Search

Peripheral T-cell lymphomas (PTCLs) are a heterogeneous group of aggressive non-Hodgkin lymphomas, the majority of which have high relapse rates following standard therapy. Despite use of consolidative stem cell transplant (SCT) following frontline therapy, there remains no consensus on its utility. The double-blind randomized phase 3 ECHELON-2 study (#NCT01777152; clinicaltrials.gov) demonstrated improved progression-free survival (PFS) and overall survival with frontline brentuximab vedotin plus cyclophosphamide, doxorubicin, and prednisone (A+CHP). Herein, we conducted an exploratory subgroups analysis of the impact of consolidative SCT on PFS in patients with previously untreated CD30+ PTCL (ALK− anaplastic large cell lymphoma [ALCL] and non-ALCL) who were in complete response (CR) after frontline treatment with A+CHP or cyclophosphamide, doxorubicin, vincristine, and prednisone. Median PFS follow-up was 47.57 months. The PFS hazard ratio was 0.36, equating to a 64% reduction in the risk of a PFS event in patients who underwent SCT. The median PFS in patients who underwent SCT was not reached, vs 55.66 months in patients who did not undergo SCT. PFS results favored the use of SCT in both ALK− ALCL and non-ALCL subgroups. These data support the consideration of consolidative SCT in patients with CD30+PTCL who achieve CR following treatment with A+CHP.

Darinaparsin is a novel organic arsenical compound of dimethylated arsenic conjugated to glutathione, with antitumor activity and a mechanism of action markedly different from other available agents. This phase II, nonrandomized, single-arm, open-label study evaluated the efficacy and safety of intravenous darinaparsin (300 mg/m2 over 1 hour, once daily for five consecutive days, per 21-day cycle) and its pharmacokinetics at multiple doses in 65 Asian patients with relapsed or refractory peripheral T-cell lymphoma (PTCL). The primary endpoint was the overall response rate (ORR). The ORR based on central assessment was 19.3% (90% confidence interval: 11.2-29.9%), which was significantly higher than the predefined threshold of 10% (p = 0.024). The ORR was 16.2% in patients with PTCL-not otherwise specified and 29.4% in patients with angioimmunoblastic T-cell lymphoma. The tumor size decreased in 62.3% of patients. Treatment-emergent adverse events (TEAEs) were observed in 98.5% of patients. Grade ≥3 TEAEs with an incidence rate ≥5% included anemia (15.4%), thrombocytopenia (13.8%), neutropenia (12.3%), leukopenia (9.2%), lymphopenia (9.2%), and hypertension (6.2%). Darinaparsin is effective and well tolerated, with TEAEs that were clinically acceptable and manageable with symptomatic treatment and dose reductions (ClinicalTrials.gov: NCT02653976).

Because of high relapse rates with rituximab combinations, there is an unmet need for new therapeutic agents for treatment of indolent B-cell non-Hodgkin lymphoma (iNHL) or follicular lymphoma (FL). In previous trials, ofatumumab in combination with chemotherapy showed good results in relapsed/refractory FL pretreated with rituximab. This phase 3 trial evaluated the efficacy and safety of single-agent ofatumumab vs single-agent rituximab in rituximab-sensitive relapsed FL that relapsed at least 6 months after completing the last prior treatment with single-agent rituximab or a rituximab-containing regimen. Patients were randomized 1:1 to receive either ofatumumab (1000 mg) or rituximab (375 mg/m2) every week for 4 weeks for the induction phase, followed by once every 2 months for 4 additional doses. The primary endpoint, progression-free survival (PFS) and secondary endpoints, overall response rate (ORR) and overall survival (OS), were evaluated. Overall, 438 patients were assigned to receive ofatumumab (n = 219) and rituximab (n = 219). Baseline characteristics were similar in both arms. The independent review committee assessed whether median PFS was shorter in the ofatumumab arm than in the rituximab arm (16.33 vs 21.29 months), with no significant difference (hazard ratio, 1.15; 95% confidence interval, 0.89-1.49; P = .29) and also showed a lower ORR (50%) compared with the rituximab arm (66%). At the time of analysis, data were not matured for OS results. The number of grade >3 adverse events was higher in the ofatumumab arm (37%) than the rituximab arm (28%). Ofatumumab showed no superiority over rituximab in patients with FL who had relapsed after a rituximab-containing therapy. This study was registered at www.clinicaltrials.gov as #NCT01200589.

Introduction The phase 3 ECHELON-2 study (NCT01777152) demonstrated that frontline treatment with brentuximab vedotin (BV) plus cyclophosphamide, doxorubicin, and prednisone (A+CHP) is superior to cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) for patients (pts) with systemic anaplastic large cell lymphoma (sALCL) or other CD30-expressing peripheral T-cell lymphomas (PTCL) (Horowitz S, et al. Lancet 2019). With a median follow-up of 36.2 months for progression-free survival (PFS), the hazard ratio (HR) (0.71 [95% confidence interval {CI}: 0.54, 0.93], P=0.01) favored A+CHP over CHOP. The median PFS was 48.2 months (95% CI: 35.2, not evaluable) versus 20.8 months (95% CI: 12.7, 47.6) for A+CHP and CHOP, respectively. With a median follow-up of 42.1 months for overall survival (OS), the HR (0.66 [95% CI: 0.46, 0.95], P=0.02) also favored A+CHP over CHOP. Median OS was not reached for either arm. With these results, A+CHP was the first treatment regimen to show an OS benefit over CHOP in this pt population. Herein, we report results with a median follow-up of 44.3 months for PFS and 55.5 months for OS. Methods ECHELON-2 is a phase 3, randomized, double-blind, double-dummy, placebo-controlled, active-comparator, multicenter study. Eligible adult pts with previously untreated CD30-positive PTCL (targeting 75% ± 5% with sALCL) were randomized to A+CHP or CHOP for six or eight cycles. Randomization was stratified by histological subtype and international prognostic index score. The primary endpoint of PFS was assessed per blinded independent central review in the primary analysis and per investigator in this updated analysis. Key secondary endpoints were OS, PFS in sALCL, complete remission (CR) rate, and objective response rate (ORR). Subsequent therapies, including BV or BV-containing regimens, were permitted. Results A total of 452 pts were enrolled and randomized 1:1 with 226 pts in each arm. The study included pts with advanced disease (Stage III [27%] and Stage IV [53%]; IPI ≥2 [78%]); given target enrollment, most pts (316 [70%]) had sALCL (218 [48%] anaplastic lymphoma kinase [ALK]-negative and 98 pts [22%] ALK-positive). With additional follow-up, the HRs for PFS per investigator (0.70 [95% CI: 0.53, 0.91], P=0.0075) (Figure 1) and OS (0.74 [95% CI: 0.54, 1.02], P=0.0688) continue to favor A+CHP over CHOP. The median PFS was 63.5 months (95% CI: 42.0, not evaluable) versus 23.8 months (95% CI: 13.6, 55.9) for A+CHP and CHOP, respectively. The estimated 5-year PFS was 50.9% (95% CI: 42.1, 59.1) for the A+CHP arm versus 42.7% (95% CI: 35.3, 49.8) for the CHOP arm. Median OS was not reached for either arm. The estimated 5-year OS was 68.7% (95% CI: 61.3, 75.0) for the A+CHP arm versus 60.3% (95% CI: 52.8, 67.0) for the CHOP arm. The PFS analyses for key prespecified subgroups were generally consistent with the overall study results (Figure 2). In the subset of pts with sALCL, the HR for PFS (0.55 [95% CI: 0.39, 0.78]) also favors A+CHP over CHOP, with an estimated 5-year PFS of 59.8% (95% CI: 48.0, 69.7) for the A+CHP arm versus 48.1% (95% CI: 39.1, 56.6) for the CHOP arm. A total of 23 pts (10%) in the A+CHP arm (16 pts with sALCL, 4 pts with PTCL not otherwise specified, and 3 pts with angioimmunoblastic T-cell lymphoma) and 51 pts (23%) in the CHOP arm received subsequent systemic therapy with BV. In the A+CHP arm, the median time to retreatment was 12.3 months (range, 3, 51); 15 pts (ORR: 65%) had CR (9 pts) or partial remission (6 pts) after retreatment with BV monotherapy (21 pts) or BV-containing regimen (2 pts). With additional follow-up in pts with treatment-emergent peripheral neuropathy (PN) (117 pts A+CHP and 124 pts CHOP), 68% of pts in the A+CHP arm had either resolution or improvement of these events compared with 77% of pts in the CHOP arm. Of the pts with ongoing PN events at last follow-up, 73% in A+CHP arm and 74% in the CHOP arm had grade 1 events, 25% and 23% of pts, respectively, had grade 2 events, and 2% of pts in each arm had grade 3 events. Conclusions At 5 years, frontline treatment with A+CHP continues to provide clinically meaningful improvement in PFS and OS versus CHOP, including ongoing remission in ~60% of pts with sALCL, with a manageable safety profile, including continued resolution or improvement of PN. Additional 5-year results, including data from prespecified subgroups, will be presented. Disclosures Horwitz: C4 Therapeutics: Consultancy; Daiichi Sankyo: Research Funding; Affirmed: Consultancy; GlaxoSmithKline: Consultancy; Janssen: Consultancy; Kura Oncology: Consultancy; Miragen: Consultancy; Myeloid Therapeutics: Consultancy; Verastem: Consultancy, Research Funding; ASTEX: Consultancy; Vividion Therapeutics: Consultancy; Beigene: Consultancy; ADCT Therapeutics: Consultancy, Research Funding; Aileron: Consultancy, Research Funding; Celgene: Consultancy, Research Funding; Forty Seven: Consultancy, Research Funding; Infinity/Verastem: Research Funding; Kyowa Hakka Kirin: Consultancy, Research Funding; Millenium/Takeda: Consultancy, Research Funding; Seattle Genetics: Consultancy, Research Funding; Trillium: Consultancy, Research Funding; Corvus: Consultancy; Innate Pharma: Consultancy; Mundipharma: Consultancy; Portola: Consultancy, Research Funding. Pro:Verastem Oncology: Research Funding. Illidge:Takeda: Current Employment, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Iyer:Legend Biotech: Consultancy; Rhizen: Research Funding; Spectrum: Research Funding; CRISPR: Research Funding; Curio Biosciences: Honoraria; Trillium: Research Funding; Target Oncology: Honoraria; Afffimed: Research Funding; Daiichi Sankyo: Consultancy; Merck: Research Funding; Seattle Genetics, Inc.: Research Funding. Advani:Astra Zeneca, Bayer Healthcare Pharmaceuticals, Cell Medica, Celgene, Genentech/Roche, Gilead, KitePharma, Kyowa, Portola Pharmaceuticals, Sanofi, Seattle Genetics, Takeda: Consultancy; Celgene, Forty Seven, Inc., Genentech/Roche, Janssen Pharmaceutical, Kura, Merck, Millenium, Pharmacyclics, Regeneron, Seattle Genetics: Research Funding. Bartlett:BTG: Consultancy; Seattle Genetics: Membership on an entity's Board of Directors or advisory committees, Research Funding; ADC Therapeutics: Consultancy; Forty Seven: Research Funding; Autolus: Research Funding; Acerta: Consultancy; Pfizer: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Immune Design: Research Funding; Janssen: Research Funding; Kite, a Gilead Company: Research Funding; Merck: Research Funding; Millennium: Research Funding; Pharmacyclics: Research Funding; Seattle Genetics: Consultancy, Research Funding; Affimed Therapeutics: Research Funding; BMS/Celgene: Research Funding; Roche/Genentech: Consultancy, Research Funding. Christensen:Odense University Hospital: Current Employment; Seattle Genetics, Inc.: Research Funding. Morschhauser:Abbvie: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees; Epizyme: Membership on an entity's Board of Directors or advisory committees; Gilead: Consultancy, Membership on an entity's Board of Directors or advisory committees; Janssen: Honoraria; Roche: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Servier: Consultancy. Domingo-Domenech:Takeda: Consultancy, Other: Travel, accomodations and expenses , Research Funding; Bristol-Myers Squibb: Other: Travel, Research Funding; Roche: Other: Travel, accomodations and expenses ; Janssen: Other: Travel, accomodations and expenses ; Seattle Genetics, Inc.: Research Funding. Rossi:Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees; Novartis: Other: Advisory board; Astellas: Membership on an entity's Board of Directors or advisory committees; Amgen: Honoraria; Daiichi Sankyo: Consultancy, Honoraria; Sanofi: Honoraria; Jazz: Membership on an entity's Board of Directors or advisory committees; Janssen: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees; Pfizer: Membership on an entity's Board of Directors or advisory committees; Alexion: Membership on an entity's Board of Directors or advisory committees; Abbvie: Membership on an entity's Board of Directors or advisory committees. Kim:Donga: Research Funding; Joihnson & Johnson: Research Funding; Kyowa Kirin: Research Funding; Mundipharma: Research Funding; Pfizer: Research Funding; Roche: Research Funding; Takeda: Research Funding; Celltrion: Research Funding. Feldman:Celgene: Honoraria, Research Funding; Cell Medica: Research Funding; Amgen: Research Funding; Kite: Honoraria, Other: Travel expenses, Speakers Bureau; Rhizen: Research Funding; Janssen: Speakers Bureau; Pharmacyclics: Honoraria, Other, Speakers Bureau; AstraZeneca: Consultancy; Bayer: Consultancy, Honoraria; Abbvie: Honoraria; Takeda: Honoraria, Other: Travel expenses; Pfizer: Research Funding; BMS: Consultancy, Honoraria, Research Funding; Trillium: Research Funding; Portola: Research Funding; Corvus: Research Funding; Kyowa Kirin: Consultancy, Research Funding; Eisai: Research Funding; Seattle Genetics, Inc.: Consultancy, Honoraria, Other: Travel expenses, Research Funding, Speakers Bureau; Viracta: Research Funding. Menne:Daiichi Sankyo: Honoraria; Kyowa Kirin: Other: Travel expenses; Pfizer: Honoraria, Other; Roche: Honoraria; Bayer: Other: Travel expenses; Kite/Gilead: Honoraria, Other: Travel expenses; Novartis: Honoraria, Research Funding; Celgene: Honoraria, Other: Travel expenses; Takeda: Honoraria; Atara: Honoraria; AstraZeneca: Research Funding; Amgen: Honoraria, Other: Travel expenses; Janssen: Honoraria, Research Funding. Belada:Takeda: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Travel expenses, Research Funding; Roche: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Travel expenses, Research Funding; Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Gilead: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Travel expenses, Research Funding; Celgene: Research Funding. Illés:Celgene, Janssen, Novartis,Roche, Takeda: Consultancy; Novartis, Janssen, Pfizer, Roche;: Other: Travel, Accommodations, Expenses; Janssen, Celgene, Takeda, Novartis Pharma SAS, Pfizer Pharmaceuticals Israel, Roche;: Consultancy, Honoraria; Takeda, Seattle Genetics: Research Funding. Tobinai:Daiichi Sankyo: Consultancy, Honoraria; Kyowa Kirin: Consultancy, Honoraria; Bristol-Myers Squibb: Honoraria; Celgene: Consultancy, Honoraria; Mundipharma: Consultancy, Honoraria; Ono Pharma: Consultancy, Honoraria; Solasia: Honoraria; SymBio: Consultancy; Takeda: Consultancy, Honoraria; HUYA Bioscience: Consultancy, Honoraria; Eisai: Honoraria; Yakult: Consultancy, Honoraria; Zenyaku Kogyo: Consultancy, Honoraria; Chugai Pharma: Consultancy, Honoraria. Tsukasaki:Ono Pharma: Consultancy; Mundy Pharma: Honoraria; HUYA: Consultancy, Research Funding; Kyowa Kirin: Honoraria, Research Funding; Celgene: Honoraria; Chugai Pharma: Honoraria, Research Funding; Daiichi Sankyo: Consultancy; Eizai: Research Funding; Seattle Genetics: Research Funding. Yeh:AbbVie: Membership on an entity's Board of Directors or advisory committees; Amgen: Membership on an entity's Board of Directors or advisory committees; Janssen: Membership on an entity's Board of Directors or advisory committees; Astellas: Membership on an entity's Board of Directors or advisory committees; Astex: Membership on an entity's Board of Directors or advisory committees. Shustov:Seattle Genetics: Research Funding. Hüttmann:Lead Discovery Center GmbH: Consultancy; Celgene: Honoraria, Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company); Gilead: Honoraria; Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company); Roche: Other: Travel expenses; Seattle Genetics: Research Funding; University Hospital Essen, University of Duisburg-Essen, Essen, Germany: Current Employment. Savage:Verastem: Honoraria; Takeda: Honoraria; Servier: Consultancy; Seattle Genetics: Consultancy, Honoraria, Research Funding; Merck: Consultancy, Honoraria; Bristol-Myers Squibb: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Abbvie: Consultancy, Honoraria. Zinzani:Roche: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; AbbVie: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; TG Therapeutics, Inc.: Honoraria, Speakers Bureau; EUSA Pharma: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Merck: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Immune Design: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Kirin Kyowa: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; ADC Therapeutics: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Sanofi: Consultancy, Membership on an entity's Board of Directors or advisory committees; Verastem: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Janssen: Consultancy, Honoraria, Speakers Bureau; Servier: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Incyte: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Kyowa Kirin: Consultancy, Speakers Bureau; Eusapharma: Consultancy, Speakers Bureau; Portola: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Immune Design: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Sandoz: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; MSD: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Janssen-Cilag: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Celltrion: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Gilead: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; BMS: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Miao:Takeda: Current equity holder in publicly-traded company. Bunn:Seattle Genetics: Research Funding; Takeda: Current Employment. Fenton:Seattle Genetics: Current Employment, Current equity holder in publicly-traded company. Fanale:Seattle Genetics: Current Employment, Current equity holder in publicly-traded company. Puhlmann:Seattle Genetics: Current Employment, Current equity holder in publicly-traded company. Truemper:Janssen: Consultancy; Mundipharma: Research Funding; Nordic Nanovector: Consultancy; Roche: Research Funding; Seattle Genetics: Research Funding; Takeda Europe: Consultancy, Research Funding.

Risk of hepatitis B virus (HBV) reactivation was assessed in B-cell non-Hodgkin lymphoma (NHL) patients with resolved HBV infection (hepatitis B surface antigen negative, hepatitis B core antibody positive) who received obinutuzumab- or rituximab-containing immunochemotherapy in the phase 3 GOYA and GALLIUM studies. HBV DNA monitoring was undertaken monthly to 1 year after the last dose of study drug. In case of HBV reactivation (confirmed, HBV DNA ≥29 IU/mL), immunochemotherapy was withheld and nucleos(t)ide analog treatment (preemptive NAT) started. Immunochemotherapy was restarted if HBV DNA became undetectable or reactivation was not confirmed, and discontinued if HBV DNA exceeded 100 IU/mL on NAT. Prophylactic NAT was allowed by investigator discretion. Among 326 patients with resolved HBV infection, 27 (8.2%) had HBV reactivation, occurring a median of 125 days (interquartile range, 85-331 days) after the first dose. In 232 patients without prophylactic NAT, 25 (10.8%) had HBV reactivation; all received preemptive NAT. Ninety-four patients received prophylactic NAT; 2 (2.1%) had HBV reactivation. No patients developed HBV-related hepatitis. On multivariate Cox analysis, detectable HBV DNA at baseline was strongly associated with an increased risk of reactivation (adjusted hazard ratio [HR], 18.22; 95% confidence interval [CI], 6.04-54.93; P < .0001). Prophylactic NAT was strongly associated with a reduced risk (adjusted HR, 0.09; 95% CI, 0.02-0.41; P = .0018). HBV DNA monitoring–guided preemptive NAT was effective in preventing HBV-related hepatitis during anti–CD20-containing immunochemotherapy in B-cell NHL patients with resolved HBV infection. Antiviral prophylaxis was also effective and may be appropriate for high-risk patients. These trials were registered at www.clinicaltrials.gov as NCT01287741 (GOYA) and NCT01332968 (GALLIUM).

Adult T-cell leukemia/lymphoma (ATL) is a heterogeneous group of peripheral T-cell malignancies characterized by human T-cell leukemia virus type-1 infection, whose genetic profile has recently been fully investigated. However, it is still poorly understood how these alterations affect clinical features and prognosis. We investigated the effects of genetic alterations commonly found in ATL on disease phenotypes and clinical outcomes, based on genotyping data obtained from 414 and 463 ATL patients using targeted-capture sequencing and single nucleotide polymorphism array karyotyping, respectively. Aggressive (acute/lymphoma) subtypes were associated with an increased burden of genetic and epigenetic alterations, higher frequencies of TP53 and IRF4 mutations, and many copy number alterations (CNAs), including PD-L1 amplifications and CDKN2A deletions, compared with indolent (chronic/smoldering) subtypes. By contrast, STAT3 mutations were more characteristic of indolent ATL. Higher numbers of somatic mutations and CNAs significantly correlated with worse survival. In a multivariate analysis incorporating both clinical factors and genetic alterations, the Japan Clinical Oncology Group prognostic index high-risk, older age, PRKCB mutations, and PD-L1 amplifications were independent poor prognostic factors in aggressive ATL. In indolent ATL, IRF4 mutations, PD-L1 amplifications, and CDKN2A deletions were significantly associated with shorter survival, although the chronic subtype with unfavorable clinical factors was only marginally significant. Thus, somatic alterations characterizing aggressive diseases predict worse prognosis in indolent ATL, among which PD-L1 amplifications are a strong genetic predictor in both aggressive and indolent ATL. ATL subtypes are further classified into molecularly distinct subsets with different prognosis. Genetic profiling might contribute to improved prognostication and management of ATL patients.

Background: Enhancer of zeste homolog 2 (EZH2) and its close homolog, EZH1, catalyze the attachment of 3 methyl groups to histone H3 at lysine 27 (H3K27me3). H3K27me3 is an epigenetic mark involved in downregulating gene expression associated with tumor suppression and cell differentiation. Recent evidence suggests that adult T-cell leukemia/lymphoma (ATL) can be driven by epigenetic dysregulation (Blood. 2016;127:1790-1802). Specifically, altered EZH2 expression has been implicated in the development and progression of ATL. Valemetostat tosylate (DS-3201b; valemetostat) is a novel, potent, and selective dual inhibitor of EZH2 and EZH1 that has demonstrated antitumor activity against hematologic malignancies, especially T-cell lymphoma, including relapsed or refractory (R/R) ATL in a phase 1 study (EHA 2021. Abstract S218). Here, we report the results from the primary analysis of a pivotal phase 2 study of valemetostat in Japanese patients (pts) with R/R ATL. Aims: This multicenter, single-arm, open-label, phase 2 study (NCT04102150) evaluated the efficacy and safety of single-agent valemetostat in pts with R/R ATL. The primary objective was to evaluate efficacy by central efficacy assessment committee (EAC)-assessed overall response rate (ORR), defined as the proportion of pts whose best response was complete remission (CR), uncertified CR, or partial remission using international consensus criteria (J Clin Oncol. 2009;27:453-59). The null hypothesis was an ORR of ≤5% (binomial test with a 1-sided significance level of 5%). Secondary outcome measures included CR rate, duration of response (DOR) per EAC, efficacy per investigator (INV) assessment, and the safety and pharmacokinetics of valemetostat. Methods: Pts ≥20 years of age with R/R ATL (acute, lymphomatous, or unfavorable chronic type) were enrolled from 24 sites in Japan. Pts must have had a positive antihuman T-cell leukemia virus type 1 antibody serum test and received prior therapy with mogamulizumab or ≥1 prior systemic therapy in the case of intolerance of, or contraindication for, mogamulizumab. Pts with prior allogeneic hematopoietic stem cell transplant were excluded. Valemetostat 200 mg was orally administered once daily in continuous 28-day cycles until disease progression or intolerance. The EAC-determined efficacy assessment was based on central evaluation of radiographic images and clinical data, including peripheral blood, skin, and bone marrow lesions (J Clin Oncol. 2009;27:453-59). Results: At the time of data cutoff (April 24, 2021), the study enrolled the planned 25 pts which included 16, 6, and 3 pts with acute, lymphomatous, or unfavorable chronic ATL subtypes, respectively. The median age was 69 years (range, 59-84 years). The median number of prior lines of therapy was 3 (range, 1-8). 24 pts (96.0%) had prior treatment with mogamulizumab. The study met its primary endpoint: with a median follow-up of 28 weeks (range, 14-71 weeks), valemetostat resulted in a 48% (12/25) ORR per EAC assessment (P 8 of 25 pts (32%) remained on treatment. 25 pts (100%) experienced ≥1 treatment-emergent adverse event (TEAE). Grade ≥3 TEAEs occurred in 15 pts (60%), and grade ≥3 serious TEAEs occurred in 6 pts (24%); valemetostat was not associated with any deaths. Dose interruption or reduction due to TEAEs occurred in 5 (20%) and 2 (8%) pts, respectively. Two pts (8%) discontinued due to TEAEs. The most common TEAEs (≥30% of pts) were platelet count decreased (80%), dysgeusia (36%), anemia (48%), and alopecia (40%); grade ≥4 platelet count decreased occurred in 3 pts (12%). Summary/Conclusions: Valemetostat resulted in a high response rate and durable antitumor effect in Japanese pts with R/R ATL, the majority of whom were pretreated with mogamulizumab. Valemetostat's safety profile was manageable. These results are consistent with those observed in the phase 1 study conducted in Japan and the US, suggesting that valemetostat could be a new treatment option for pts with R/R ATL. Valemetostat is also being evaluated in a global phase 2 study in pts with R/R ATL and R/R peripheral T-cell lymphoma (NCT04703192). Figure 1 Figure 1. Disclosures Yoshimitsu: Sanofi: Honoraria; Takeda: Honoraria; Novartis: Honoraria. Izutsu: Kyowa Kirin: Honoraria, Research Funding; Incyte: Research Funding; Chugai: Honoraria, Research Funding; Bayer: Research Funding; Beigene: Research Funding; AstraZeneca: Honoraria, Research Funding; Yakult: Research Funding; AbbVie: Honoraria, Research Funding; Takeda Pharmaceutical: Honoraria, Research Funding; HUYA Bioscience International: Research Funding; Eisai: Honoraria, Research Funding; MSD: Research Funding; Janssen: Honoraria, Research Funding; Genmab: Honoraria, Research Funding; Celgene: Honoraria, Research Funding; Daiichi Sankyo: Honoraria, Research Funding; Novartis: Honoraria, Research Funding; Ono: Honoraria, Research Funding; Pfizer: Research Funding; Symbio: Honoraria, Research Funding; Allergan Japan: Honoraria; FUJI FILM Toyama Chemical: Honoraria. Makita: Takeda: Consultancy, Honoraria; SymBio: Honoraria; Novartis: Honoraria; Eisai: Honoraria; Daiichi-Sankyo: Consultancy; CSL Behring: Honoraria; Chugai: Honoraria; BMS: Consultancy, Honoraria. Nosaka: Eisai Co., Ltd: Honoraria; Celgene K.K.: Honoraria; Kyowa Kirin Co., Ltd: Consultancy, Honoraria, Research Funding; Meiji Seika Parma Co., Ltd: Honoraria; Chugai Pharmaceutical Co., Ltd.: Research Funding; Janssen Pharmaceutical K.K.: Honoraria; Bristol Myers Squibb: Honoraria. Utsunomiya: Novartis Pharma: Honoraria; Kyowa Kirin: Honoraria; Daiichi Sankyo: Honoraria; Celgene: Honoraria; Pfizer: Honoraria; Janssen Pharmaceutical: Honoraria; JIMRO: Honoraria; Meiji Seika Pharma: Honoraria; Otsuka Medical Devices: Honoraria. Kusumoto: Daiichi Sankyo: Research Funding; Chugai: Honoraria, Research Funding; Kyowa Kirin: Honoraria. Tsukasaki: Solasia Pharma: Consultancy; Meiji Seika Pharma: Consultancy; Yakuruto: Consultancy; HUYABIO: Consultancy, Research Funding; Ono Pharma: Consultancy; Daiichi Sankyo: Consultancy, Research Funding; Takeda: Honoraria; Kyowa-hakko/Kirin: Honoraria, Research Funding; Eizai: Honoraria, Research Funding; Byer: Research Funding; Chugai Pharma: Honoraria, Research Funding; Celgene: Honoraria, Research Funding. Ono: Chugai Pharmaceutical Co., Ltd.: Honoraria, Research Funding; Eisai Co., Ltd.: Honoraria; Janssen Pharmaceutical K.K: Honoraria; DAIICHI SANKYO COMPANY, LIMITED.: Honoraria; Mundipharma K.K.: Honoraria; TAIHO PHARMACEUTICAL CO., LTD.: Research Funding; Merck Sharp & Dohme: Honoraria, Research Funding; Astellas Pharma Inc.: Honoraria; Bristol-Myers Squibb Company: Honoraria; Novartis Pharma KK: Honoraria; Pfizer Japan Inc.: Honoraria; Otsuka Pharmaceutical Co., Ltd.: Honoraria; ONO PHARMACEUTICAL CO., LTD.: Honoraria, Research Funding; Takeda Pharmaceutical Company Limited.: Honoraria; Kyowa Kirin Co., Ltd.: Honoraria, Research Funding; Celgene: Honoraria, Research Funding. Rai: Chugai Pharmaceutical: Speakers Bureau; Ono Pharmaceutical: Speakers Bureau; Janssen Pharmaceutical: Speakers Bureau. Yamada: Daiichi Sankyo: Current Employment. Kato: Bristol Myers Squibb: Current equity holder in publicly-traded company; Daiichi Sankyo: Current Employment. Tachibana: Daiichi Sankyo: Current Employment. Kakurai: Daiichi Sankyo: Current Employment. Adachi: Daiichi Sankyo: Current Employment. Tobinai: Celgene: Consultancy, Honoraria; Chugai Pharmaceutical: Honoraria; Eisai: Honoraria; Daiichi Sankyo: Consultancy, Honoraria; HUYA Bioscience International: Consultancy, Honoraria; Kyowa Kirin: Honoraria; Mundipharma: Consultancy, Honoraria; Ono Pharmaceutical: Consultancy, Honoraria; Solasia Pharma: Honoraria; Takeda Pharmaceutical: Consultancy, Honoraria; Yakult: Honoraria; Zenyaku Kogyo: Consultancy, Honoraria. Yonekura: AbbVie: Honoraria; Amgen: Honoraria; Celgene: Honoraria; Daiichi Sankyo: Honoraria; Eisai: Honoraria; Eli Lilly Japan: Honoraria; Janssen Pharmaceuticals: Honoraria; Kaken Pharmaceutical: Honoraria; Kyowa Kirin: Honoraria; Maruho: Honoraria; Minophagen Pharmaceutical: Honoraria; Novartis: Honoraria; Sanofi: Honoraria; Taiho Pharmaceutical: Honoraria; Torii Pharmaceutical: Honoraria; UCB Japan: Honoraria. Ishitsuka: Pfizer: Other: Personal fees; Astellas Pharma: Other: Personal fees, Research Funding; Genzyme: Other: Personal fees; Sumitomo Dainippon Pharma: Other: Personal fees, Research Funding; Eisai: Other: Personal fees, Research Funding; Novartis: Other: Personal fees; Janssen Pharmaceuticals: Other: Personal fees; Taiho Pharmaceuticals: Other: Personal fees, Research Funding; Mundipharma: Other: Personal fees; Takeda: Other: Personal fees, Research Funding; BMS: Other; Chugai Pharmaceutical: Honoraria, Other: Personal fees, Research Funding; Celgene: Honoraria, Other: Personal fees; Ono Pharmaceutical: Other: Personal fees, Research Funding; Kyowa Kirin: Other: Personal fees, Research Funding; Daiichi Sankyo: Consultancy, Other: Personal fees; Mochida: Other: Personal fees, Research Funding; Shire: Other; Otsuka Pharmaceutical: Other: Personal fees; Teijin Pharma: Research Funding; MSD: Research Funding; Asahi kasei: Research Funding; Eli Lilly: Research Funding; Huya Japan: Other: Personal fees.

Introduction While patients with r/r TCL have a poor prognosis, significant progress has been made over the past decade in developing new drugs and regimens for the disease. All of the approved agents have their own distinct advantages and issues, making it essential to critically assess the merits and limitations of each. It is well accepted that the development of acquired drug resistance to conventional chemotherapy reduces efficacy with each subsequent line of therapy. However in the era of novel single agents, less is known about the role of these new drugs in patients with chemo-sensitive and chemo-refractory disease. Based on results of the PROPEL trial in 111 treated patients, pralatrexate was the first drug approved as a novel single agent in the US for r/r TCL (O'Connor et al. J Clin Oncol. 2011). Drug registration and approval of pralatrexate was subsequently attained in many healthcare ministries around the world, including Japan, China and Taiwan based on the results of PROPEL and/or locally conducted studies (Maruyama et al. Cancer Sci 2017; Hong et al. Target Oncol 2019; Wang et al. EHA 2019). A meta-analysis of these four trials was undertaken to better understand those factors influencing efficacy and safety of pralatrexate in this patient population. Methods Patient- or summary-level data presented in the individual clinical study reports from the four regulatory-mandated prospective clinical trials of pralatrexate monotherapy in patients with r/r TCL were included in this meta-analysis. Pooled studies (phase 2 PDX-008 [PROPEL], phase 3 FOT12-CN-301, phase 4 FOT14-TW-401, phase 2 part of PDX-JP1) collected data on the primary efficacy endpoint of objective response rate (ORR) as assessed by central review. Secondary efficacy endpoints included duration of response (DOR), progression-free survival (PFS), and overall survival (OS). Data were collected in accordance with the original protocol and updated with longer survival follow-up where available. Relapse was defined as achieving a complete response (CR) or partial response (PR) on prior therapy lasting for > 3 months, and refractory was defined as stable disease or progressive disease on prior therapy or relapsed disease Results A total of 221 patients were included in the efficacy analysis set for this meta-analysis. The median age was 59 years (range 21-89) and 67% were male. Histological subtypes as assessed by the central review included PTCL-not otherwise specified (108 pts, 49%), angioimmunoblastic T-cell lymphoma (47 pts, 21%), anaplastic large cell lymphoma (ALK-negative; 26 pts, 12%), transformed mycosis fungoides (12 pts, 5%), extranodal NK/T cell lymphoma, nasal type (7 pts, 3%), and other/missing (10/11 pts, 5% each). Patients had a median of 2 prior lines of systemic therapies (range 1-14). At the most recent line of therapy prior to pralatrexate, 68 (31%) and 103 (47%) patients were classified as relapsed and refractory respectively, with the remaining 50 (23%) unable to be determined due to response to the prior therapy being unavailable or not evaluable. Ten percent (n=24) of patients had stem cell transplant prior to receiving pralatrexate. Pooled ORR of the entire cohort was 40.7% (95% CI, 34.2, 47.5), including 30 in CR (13.6%) and 60 in PR (27.2%). The median DOR was 9.1 months (95% CI, 7.4-10.8). Median PFS was 4.6 months (95% CI, 4.0-5.2) while median OS was 16.3 months (95% CI, 13.1-22.6). Conclusions This meta-analysis confirms significant clinical activity of pralatrexate in heavily treated patients with r/r TCL, with an ORR of 40.7% at a median of two lines of prior therapy. These findings meaningfully bolster the original observations from PROPEL with 3 additional regulatory mandated clinical studies and suggest that earlier use may be associated with improved outcome. Further details on the efficacy by prior lines of systemic therapy as well as safety data will be presented. Disclosures O'Connor: TG Therapeutics: Current Employment, Current equity holder in publicly-traded company; Merck: Research Funding; BMS: Research Funding; Astex: Research Funding; Kymera: Current equity holder in publicly-traded company, Honoraria, Membership on an entity's Board of Directors or advisory committees; Servier: Research Funding; Mundipharma: Honoraria; Myeloid Therapeutics: Current equity holder in publicly-traded company, Honoraria, Membership on an entity's Board of Directors or advisory committees. Maruyama: Novartis: Research Funding; Chugai: Honoraria, Research Funding; Amgen: Research Funding; BMS: Honoraria, Research Funding; Astellas Pharma,: Research Funding; Otsuka: Research Funding; MSD: Honoraria, Research Funding; Sanofi: Honoraria, Research Funding; Janssen: Honoraria, Research Funding; Takeda: Honoraria, Research Funding; Eisai: Honoraria, Research Funding; Ono: Honoraria, Research Funding; AbbVie: Honoraria, Research Funding; Celgene: Honoraria, Research Funding; Mundipharma: Honoraria; Kyowa Kirin: Honoraria; Zenyaku: Honoraria; AstraZeneca: Honoraria; Nippon: Honoraria; SymBio: Honoraria. Yeoh: Mundipharma: Current Employment. Tobinai: Celgene: Consultancy, Honoraria; Chugai Pharmaceutical: Honoraria; Eisai: Honoraria; Daiichi Sankyo: Consultancy, Honoraria; HUYA Bioscience International: Consultancy, Honoraria; Kyowa Kirin: Honoraria; Mundipharma: Consultancy, Honoraria; Ono Pharmaceutical: Consultancy, Honoraria; Solasia Pharma: Honoraria; Takeda Pharmaceutical: Consultancy, Honoraria; Yakult: Honoraria; Zenyaku Kogyo: Consultancy, Honoraria.

Background: Darinaparsin is a novel organic arsenic compound composed of dimethylated arsenic linked to glutathione. In two phase I studies including Japanese and Korean patients with relapsed or refractory peripheral T-cell lymphoma (PTCL), darinaparsin was well tolerated and demonstrated potential efficacy (ASH2015 Abstract #2714 and Jpn J Clin Oncol. 2021, 51:218). The efficacy, safety and pharmacokinetics of darinaparsin in Asian patients with relapsed or refractory PTCL were evaluated in a multinational phase II study. Methods: Eligible patients had histologically confirmed PTCL not otherwise specified (PTCL-NOS), angioimmunoblastic T-cell lymphoma (AITL) or anaplastic large cell lymphoma (ALCL), which had relapsed from or were refractory to one or more prior regimen with systemic chemotherapy. Darinaparsin was intravenously administered for 5 consecutive days at 300 mg/m 2/day every 3 weeks. The primary endpoint was the overall response rate (ORR) within 6 cycles of treatment. Tumor response was assessed based on computed tomography (CT) and fluorodeoxyglucose-positron emission tomography (FDG-PET) evaluation by central review according to the Revised Response Criteria for Malignant Lymphoma (J Clin Oncol. 2007, 25:579). Secondary endpoints included progression-free survival (PFS), overall survival (OS), toxicity, and pharmacokinetic parameter. This study was conducted in 25 sites in East Asia (13 in Japan, 6 in Korea, 5 in Taiwan, and 1 in Hong Kong). Results: A total of 65 patients (37, 19, 8 and 1 from Japan, Korea, Taiwan and Hong Kong, respectively) including 43 PTCL-NOS, 17 AITL and 3 ALK-negative ALCL; 45 males and 20 females, with a median age of 68 (range 28-85) years received darinaparsin. The median number of prior systemic chemotherapy regimens was 2 (range 1-11). Approximately 30% of patients did not have evidence of response to the most recent prior systemic therapy. The median number of cycles received darinaparsin was 3 (range 1-39). In 57 evaluable patients, the ORR as assessed by an independent efficacy assessment committee was 19% (11 of 57; 90% Confidence Interval (CI) 11.2-29.9), and the lower limit of the 90% CI exceeded the predefined 10% threshold (p=0.024, binomial test). The ORR was 16.2% (6 of 37) in the subjects with PTCL-NOS and 29.4% (5 of 17) in the subjects with AITL. None of the subjects with ALCL, ALK-negative responded. Of the 11 responders, 5 achieved a Complete Response (CR) (8.8%), and 6 had a Partial Response (PR) (10.5%). Eight of the 11 responders showed response by Cycle 3. The disease control rate defined as the proportion of patients who achieved CR, PR or Stable Disease (SD) was 46% (26 of 57, 90% CI 34.3-57.3), and more than half of the patients achieved tumor shrinkage (Figure 1). Median duration of response (DOR) was 3.8 months (90% CI 2.7-5.7). Four patients who had achieved SD or better continued the treatment with darinaparsin for more than 1 year, and median duration of treatment in these subjects was 28.6 months (range 14-41). Median PFS and OS were 3.3 months (90% CI 1.9-4.2) and 13.7 months (90% CI 9.9-18.6), respectively. Among all 65 treated patients, the incidence of adverse events (AEs) was 97%, and that of drug-related AEs was 68%. AEs with an incidence of ≥ 20% were pyrexia (42%), anemia (25%), thrombocytopenia (20%) and decreased appetite (20%). The incidence of ≥ Grade 3 AEs was 62%, and that of ≥ Grade 3 drug-related AEs was 29%. The common ≥ Grade 3 AEs were anemia (15%), thrombocytopenia (12%), neutropenia (12%), lymphopenia (9%) and leukopenia (9%). While electrocardiogram (ECG) QT prolongation at 3% was reported as drug-related AEs associated with cardiac toxicity, there were no substantial changes from baseline in the descriptive statistics of ECG parameters associated with darinaparsin treatment. There was no apparent ethnic difference in pharmacokinetic profiles of patients studied. Conclusions: Darinaparsin had clinical efficacy and was well tolerated in patients with relapsed or refractory PTCL. AEs were clinically acceptable and manageable. Darinaparsin is a potential option for the treatment of relapsed or refractory PTCL. Updated results of DOR PFS, OS, and long-term safety are being analyzed for presentation at the conference. Figure 1 Figure 1. Disclosures Fukuhara: Ono Pharmaceutical: Honoraria, Research Funding; Novartis: Honoraria; Nippon Shinyaku: Honoraria; Kyowa Kirin: Honoraria; Janssen: Honoraria; Incyte: Research Funding; HUYA Bioscience International: Honoraria; Eisai: Honoraria; Chugai Pharmaceutical: Honoraria, Research Funding; Celgene: Honoraria, Research Funding; Bayer: Research Funding; AbbVie: Honoraria; Takeda Pharmaceutical: Honoraria; Zenyaku Kogyo: Honoraria. Kim: Celltrion: Research Funding; Dong-A Pharmaceutical: Research Funding; Eisai: Research Funding; Johnson & Johnson: Research Funding; Kyowa Kirin: Research Funding; Roche: Research Funding; IGM Biosciences: Research Funding; Sanofi: Research Funding. Yamamoto: Nippon Shinyaku: Honoraria, Research Funding; Otsuka: Honoraria, Research Funding; Ono: Honoraria, Research Funding; Novartis: Honoraria, Research Funding; Sanofi: Honoraria; Solasia Pharma: Research Funding; SymBio: Honoraria, Research Funding; Takeda: Honoraria, Research Funding; Yakult: Honoraria, Research Funding; Zenyaku: Honoraria, Research Funding; Micron: Honoraria; IQIVA/Genmab: Research Funding; ADC Therapeutics: Honoraria; Chugai: Honoraria, Research Funding; Daiichi Sankyo: Honoraria; Eisai: Honoraria, Research Funding; IQIVA/Incyte: Research Funding; IQIVA/HUYA: Honoraria; HUYA: Consultancy; Janssen: Honoraria; Kyowa Kirin: Honoraria; Meiji Seika Pharma: Consultancy, Honoraria, Research Funding; MSD: Honoraria; Mundipharma: Research Funding; Bristol-Myers Squibb/Celgene: Honoraria, Research Funding; AstraZeneca: Honoraria, Research Funding; AbbVie: Honoraria, Research Funding. Izutsu: Novartis: Honoraria, Research Funding; Ono: Honoraria, Research Funding; Pfizer: Research Funding; Symbio: Honoraria, Research Funding; Allergan Japan: Honoraria; FUJI FILM Toyama Chemical: Honoraria; MSD: Research Funding; Janssen: Honoraria, Research Funding; Incyte: Research Funding; Genmab: Honoraria, Research Funding; Chugai: Honoraria, Research Funding; Beigene: Research Funding; Bayer: Research Funding; AstraZeneca: Honoraria, Research Funding; AbbVie: Honoraria, Research Funding; Yakult: Research Funding; Takeda Pharmaceutical: Honoraria, Research Funding; Kyowa Kirin: Honoraria, Research Funding; HUYA Bioscience International: Research Funding; Eisai: Honoraria, Research Funding; Daiichi Sankyo: Honoraria, Research Funding; Celgene: Honoraria, Research Funding. Terui: Ono Pharmaceutical: Speakers Bureau; MSD: Speakers Bureau; Janssen: Speakers Bureau; Esai: Speakers Bureau; Chugai Pharmaceutical: Speakers Bureau; Celgene: Speakers Bureau; AbbVie: Speakers Bureau; Takeda Pharmaceutical: Speakers Bureau. Ando: Astellas Pharma: Honoraria; Celgene: Honoraria; Chugai Pharmaceutical: Research Funding; Kyowa Kirin: Research Funding; Novartis: Honoraria; Takeda Pharmaceutical: Research Funding. Suehiro: Otsuka Pharmaceutical: Research Funding; Ono Pharmaceutical: Research Funding; Novartis: Research Funding; Nippon Shinyaku: Honoraria; Kyowa Kirin: Honoraria, Research Funding; Incyte: Research Funding; Eisai: Honoraria, Research Funding; Chugai Pharmaceutical: Honoraria, Research Funding; Celgene: Research Funding; Bristol-Myers Squibb: Honoraria; Bayer: Research Funding; Amgen BioPharma: Research Funding; Pfizer: Research Funding. Nagahama: Solasia Pharma: Current Employment, Current equity holder in publicly-traded company. Sonehara: Solasia Pharma: Current Employment, Current equity holder in publicly-traded company. Nagai: Ono Pharmaceutical: Honoraria; Sanofi: Honoraria; Sumitomo Dainippon Pharma: Honoraria; SymBio Pharmaceuticals: Honoraria, Research Funding; Takeda Pharmaceutical: Honoraria, Research Funding; Zenyaku Kogyo: Research Funding; Novartis: Honoraria; Nippon Shinyaku: Research Funding; Mundipharma: Honoraria, Research Funding; Kyowa Kirin: Research Funding; Janssen: Honoraria, Research Funding; Eisai: Honoraria, Research Funding; Chugai Pharmaceutical: Honoraria, Research Funding; Chordia Therapeutics: Honoraria; Celgene: Honoraria, Research Funding; Bristol-Myers Squibb: Honoraria, Research Funding; Bayer: Research Funding; AstraZeneca: Honoraria, Research Funding; AbbVie: Research Funding. Tien: Novartis: Honoraria; Celgene: Honoraria, Research Funding; AbbVie: Honoraria. Tobinai: Ono Pharmaceutical: Consultancy, Honoraria; Solasia Pharma: Honoraria; Mundipharma: Consultancy, Honoraria; Kyowa Kirin: Honoraria; HUYA Bioscience International: Consultancy, Honoraria; Daiichi Sankyo: Consultancy, Honoraria; Eisai: Honoraria; Chugai Pharmaceutical: Honoraria; Celgene: Consultancy, Honoraria; Takeda Pharmaceutical: Consultancy, Honoraria; Zenyaku Kogyo: Consultancy, Honoraria; Yakult: Honoraria. OffLabel Disclosure: Darinaparsin is an investigational product that is not approved in any country/region in the world.

Introduction The ECHELON-2 study (NCT01777152) demonstrated significantly longer progression-free survival (PFS) and overall survival with brentuximab vedotin plus cyclophosphamide, doxorubicin, and prednisone (A+CHP) versus CHOP in the frontline treatment of patients (pts) with sALCL or other CD30-expressing PTCL and supported the 2018 FDA approval in this setting. Consistent with current guidelines, pts could have received consolidative stem cell transplant (SCT) after treatment at the discretion of the treating investigator. In all pts treated with A+CHP, only 22% (50 of 226) underwent SCT. Herein, we present outcomes from an exploratory analysis of pts in a complete remission (CR) following A+CHP who received an SCT and those who did not. Methods CR rate was defined at the end of treatment (EOT) by independent review per the Revised Response Criteria for Malignant Lymphoma. ALK+ sALCL pts were excluded because they tend to have more favorable outcomes. Consolidative transplant was not considered a PFS event. A univariate analysis of SCT versus no SCT and multivariate analyses adjusting for region and age were performed. Results Sixty-seven percent (76/113 pts) of pts with ALK- sALCL on the A+CHP arm were in CR at EOT and 36% (27/76) of them received SCT. Pts who underwent SCT were younger, with a median age of 50 years (yr) (range 18-68) compared with 59 yr (range 20-85) in those without SCT. Median PFS for pts with SCT was not reached (95% CI 36.57, not estimable [NE]) versus 55.66 mos (95% CI 23.72, 55.66) for pts without SCT. Fifty-nine percent (38/64) of pts with non-sALCL on the A+CHP arm were in CR at EOT and 29% (11/38) of them received SCT. Pts who underwent SCT were younger than those without (median age 57 yr [35-73] vs 66 yr [49-77]). Median PFS for pts who did and did not receive SCT was not reached (95% CI 20.70, NE) versus 33.22 mos (95% CI 8.08, NE), respectively. Prior to treatment start, the intent to transplant in Asian countries among ALK- sALCL and non-ALCL pts was less frequent in comparison to non-Asian countries (13% and 29% vs 49% and 57%, respectively). The proportion of pts ultimately transplanted was also less frequent (13% and 12% in Asia versus 32% and 23% in non-Asian countries). Standard PFS and multivariate proportional hazards regression analyses favored the use of SCT in PTCL pts in a CR after A+CHP (Table). Conclusions Numerical PFS estimates favor the use of SCT in PTCL pts in a CR after A+CHP; however, sample sizes are small. It is also recognized that unknown confounders may impact this post-hoc analysis. We observed that use of SCT was infrequent in Asian countries, suggesting regional practice differences. The overall impact of consolidative SCT remains unconfirmed, including in patients treated with A+CHP. Further studies are needed to establish its role in this setting. Table Disclosures Savage: BMS, Merck, Novartis, Verastem, Abbvie, Servier, and Seattle Genetics: Consultancy, Honoraria; Seattle Genetics, Inc.: Consultancy, Honoraria, Research Funding. Horwitz:Millennium/Takeda: Consultancy, Research Funding; Infinity/Verastem: Consultancy, Research Funding; Trillium: Research Funding; Infinity/Verastem: Consultancy, Research Funding; Aileron: Research Funding; Kura: Consultancy; Affimed: Consultancy; Millennium/Takeda: Consultancy, Research Funding; Celgene: Consultancy, Research Funding; Trillium: Research Funding; Portola: Consultancy; Forty-Seven: Research Funding; Mundipharma: Consultancy; Celgene: Consultancy, Research Funding; ADCT Therapeutics: Research Funding; Astex: Consultancy; Astex: Consultancy; Celgene: Consultancy, Research Funding; Infinity/Verastem: Consultancy, Research Funding; Infinity/Verastem: Consultancy, Research Funding; Innate Pharma: Consultancy; Affimed: Consultancy; Affimed: Consultancy; Kura: Consultancy; ADCT Therapeutics: Research Funding; Kyowa Hakko Kirin: Consultancy; Corvus Pharmaceuticals: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Corvus Pharmaceuticals: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Kyowa Hakko Kirin: Consultancy; Astex: Consultancy; Miragen: Consultancy; Celgene: Consultancy, Research Funding; Mundipharma: Consultancy; Innate Pharma: Consultancy; Kura: Consultancy; Millennium/Takeda: Consultancy, Research Funding; Astex: Consultancy; ADCT Therapeutics: Research Funding; Affimed: Consultancy; Portola: Consultancy; Miragen: Consultancy; Aileron: Research Funding; Trillium: Research Funding; Seattle Genetics: Consultancy, Research Funding; Portola: Consultancy; Innate Pharma: Consultancy; Forty-Seven: Research Funding; Miragen: Consultancy; Kyowa Hakko Kirin: Consultancy; Aileron: Research Funding; Corvus Pharmaceuticals: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Seattle Genetics: Consultancy, Research Funding; Miragen: Consultancy; ADCT Therapeutics: Research Funding; Corvus Pharmaceuticals: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Millennium/Takeda: Consultancy, Research Funding; Kura: Consultancy; Innate Pharma: Consultancy; Seattle Genetics: Consultancy, Research Funding; Forty-Seven: Research Funding; Mundipharma: Consultancy; Seattle Genetics: Consultancy, Research Funding; Aileron: Research Funding; Kyowa Hakko Kirin: Consultancy; Trillium: Research Funding; Forty-Seven: Research Funding; Portola: Consultancy; Mundipharma: Consultancy. Advani:Regeneron: Research Funding; Pharmacyclics: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Gilead Sciences, Inc./Kite Pharma, Inc.: Consultancy, Membership on an entity's Board of Directors or advisory committees; Celmed: Consultancy, Membership on an entity's Board of Directors or advisory committees; Bristol-Myers Squibb: Membership on an entity's Board of Directors or advisory committees, Research Funding; Millennium: Research Funding; Forty-Seven: Research Funding; AstraZeneca: Consultancy, Membership on an entity's Board of Directors or advisory committees; Cell Medica, Ltd: Consultancy; Janssen: Research Funding; Merck: Research Funding; Bayer: Consultancy, Membership on an entity's Board of Directors or advisory committees; Infinity Pharma: Research Funding; Celgene: Research Funding; Kura: Research Funding; Roche/Genentech: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Kyowa Kirin Pharmaceutical Developments, Inc.: Consultancy; Takeda: Consultancy, Membership on an entity's Board of Directors or advisory committees; Autolus: Consultancy, Membership on an entity's Board of Directors or advisory committees; Stanford University: Employment, Equity Ownership; Seattle Genetics: Consultancy, Research Funding; Agensys: Research Funding. Domingo-Domenech:Roche: Other: Travel expenses; Seattle Genetics: Research Funding; Takeda: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Travel expenses; Bristol-Myers Squibb: Other: Travel expenses. Rossi:Daiichi-Sankyo: Consultancy; Celgene: Membership on an entity's Board of Directors or advisory committees; Amgen: Membership on an entity's Board of Directors or advisory committees; Gilead: Membership on an entity's Board of Directors or advisory committees; Sanofi: Membership on an entity's Board of Directors or advisory committees; Abbvie: Membership on an entity's Board of Directors or advisory committees; Pfizer: Membership on an entity's Board of Directors or advisory committees; Jazz: Membership on an entity's Board of Directors or advisory committees; Astellas: Membership on an entity's Board of Directors or advisory committees; Novartis: Honoraria; Mundipharma: Honoraria; BMS: Honoraria; Sandoz: Honoraria; Roche: Membership on an entity's Board of Directors or advisory committees; Janssen: Membership on an entity's Board of Directors or advisory committees. Morschhauser:Roche: Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen: Honoraria; Gilead: Membership on an entity's Board of Directors or advisory committees; Epizyme: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees; Bristol-Myers Squibb: Membership on an entity's Board of Directors or advisory committees; Bayer: Membership on an entity's Board of Directors or advisory committees; Seattle Genetics: Research Funding. Alpdogan:Seattle Genetics, Inc.: Research Funding. Tobinai:Meiji Seika: Honoraria; Takeda Pharmaceutical: Consultancy, Honoraria, Research Funding; Mundi Pharma: Consultancy, Honoraria, Research Funding; AbbVie: Research Funding; Chugai Pharmaceutical: Honoraria, Research Funding; Eisai: Honoraria, Research Funding; Kyowa Kirin: Honoraria, Research Funding; Verastem: Honoraria; Zenyaku Kogyo: Consultancy, Honoraria; Yakult: Honoraria; Bristol-Myers Squibb: Honoraria; HUYA Bioscience: Consultancy, Honoraria; Janssen Pharmaceutical: Honoraria, Research Funding; Celgene: Consultancy, Honoraria, Research Funding; Solasia: Honoraria; Daiichi Sankyo: Consultancy, Honoraria; Ono Pharmaceutical: Consultancy, Honoraria, Research Funding. Shustov:Seattle Genetics, Inc.: Research Funding. Trneny:Roche: Consultancy, Honoraria; Bristol-Myers Squibb: Consultancy, Honoraria; Amgen: Consultancy, Honoraria; Abbvie: Consultancy, Honoraria; Incyte: Consultancy, Honoraria; Gilead sciences: Consultancy, Honoraria; Takeda: Consultancy, Honoraria; Janssen: Consultancy, Honoraria; Morphosys: Consultancy, Honoraria. Yuen:Seattle Genetics, Inc.: Other: Travel expenses, Research Funding. Zinzani:Verastem: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; MSD: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Eusapharma: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Sanofi: Consultancy; Celltrion: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Gilead: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Janssen-Cilag: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; BMS: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Servier: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Sandoz: Membership on an entity's Board of Directors or advisory committees; Immune Design: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Celgene: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Portola: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Roche: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Kyowa Kirin: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; TG Therapeutics: Honoraria, Speakers Bureau. Truemper:Janssen Oncology: Consultancy; Nordic Nanovector: Consultancy; Seattle Genetics, Inc.: Research Funding; Mundipharma: Research Funding; Roche: Research Funding; Takeda: Consultancy, Research Funding. Illidge:Div of Cancer Sciences, Faculty of Biology, Medicine and Health, Univ of Manchester, National Institutes of Health and Research Biomedical Research Center, Manchester Academic Health Sciences, Christie Hospital National Health Service Foundation Trust: Employment; Takeda: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Seattle Genetics, Inc.: Research Funding. O'Connor:Spectrum Pharma: Consultancy, Other: Travel expenses, Research Funding; Roche: Research Funding; Seattle Genetics, Inc.: Consultancy, Other: Travel expenses, Research Funding; Allos Therapeutics: Consultancy; Acetylon Pharma: Other: Travel expenses, Research Funding; Celgene: Research Funding; Millenium: Consultancy, Honoraria, Other: Travel expenses, Research Funding; Mundipharma: Consultancy, Honoraria, Other: Travel expenses, Research Funding; Novartis: Consultancy, Honoraria. Pro:Kyowa Hakka Kirin: Consultancy, Honoraria; Takeda: Consultancy, Honoraria, Other: Travel Expenses; Celgene: Consultancy, Honoraria; Seattle Genetics: Consultancy, Honoraria, Other: Travel Expenses, Research Funding. Little:Takeda Pharmaceuticals: Employment. Bunn:Takeda Pharmaceuticals: Employment. Fenton:Seattle Genetics, Inc.: Employment, Equity Ownership. Manley:Seattle Genetics: Employment, Equity Ownership. Iyer:Incyte: Research Funding; Bristol-Myers Squibb: Research Funding; Seattle Genetics, Inc.: Research Funding; Genentech/Roche: Research Funding; Novartis: Research Funding; Arog: Research Funding.

Introduction: MAVORIC was an open-label, multicenter, randomized phase 3 study evaluating the safety and efficacy of mogamulizumab (moga) compared to vorinostat (vori) in patients with mycosis fungoides (MF) or Sézary syndrome (SS) who had failed at least one prior course of systemic therapy (NCT01728805). Primary results have been reported (Kim et al. Lancet Oncol 2018) and were based on a data cutoff date of December 31, 2016. The primary endpoint was progression-free survival (PFS); patients in the moga treatment arm experienced significantly longer PFS compared to patients in the vori treatment arm (median 7.7 months vs 3.1 months; p Methods: Patients were randomized 1:1 to moga 1.0 mg/kg administered intravenously on Days 1, 8, 15, and 22 of the first cycle and on Days 1 and 15 of subsequent cycles or vori 400 mg administered orally once daily. Patients randomized to vori were allowed to cross over to moga upon progression or intolerable toxicity. Safety was assessed by reported adverse events (AEs), changes in physical examinations, vital sign measurements, electrocardiograms, and laboratory analyses. Results: In total, 372 patients were randomized (moga, 186; vori, 186), of whom 370 received study drug and were included in the safety analysis (moga, 184; vori, 186). For the final safety analysis, median duration of follow-up was 34.5 months (range, 0.13-70.0) in the randomized part of the study. Median treatment exposure was 170 days (range, 1-1813) for moga and 84 days (4-1230) for vori, which represent the same median values but broader ranges compared to the primary analysis (primary analysis, 170 days [1-1379] for moga and 84 days [4-1058] for vori). The type and frequency of AEs in either the moga or vori treatment groups (Table) were consistent with those reported in the primary analysis. TEAEs, regardless of causality, that were reported at similar rates in the two treatment groups included constipation, peripheral edema, headache, and anemia. TEAEs (all causality) that occurred at higher frequency in the moga vs vori arm included infusion-related reaction (33.2% vs 0.5%) and drug eruption (25.0% vs 1.1%); the majority of these events were grade 1 or 2 (Table). The types and frequencies of AEs attributable to moga (per Investigator assessment) included infusion-related reaction (33.2% [61/184]), drug eruption (23.9% [44/184]), and fatigue (18.5% [34/184]), and for vori, diarrhea (55.4% [103/186]), nausea (38.2% [71/186]), and fatigue (33.3% [62/186]). In patients who crossed over from the vori to moga arm and received study drug (n=135), the most frequently reported AEs attributable to moga were infusion-related reaction (37.8% [51/135]), drug eruption (24.4% [33/135]), fatigue (7.4% [10/135]), increased alanine aminotransferase (7.4% [10/135]), and increased aspartate aminotransferase (7.4% [10/135]). Discontinuation rates due to AEs were similar between treatment arms and in crossover patients (moga, 21.7% [40/184]; vori, 23.7% [44/186]; crossover, 25.9% [35/135]). The most common AEs leading to discontinuation were drug eruption in the moga arm (7.1% [13/184]) and fatigue in the vori arm (4.3% [8/186]). Overall, the rates of drug-related serious TEAEs were similar between treatment arms and in crossover patients (moga, 19.6% [36/184]; vori, 16.7% [31/186]; crossover, 11.9% [16/135]). After the data cutoff for the primary analysis, 1 additional patient randomized to moga (decreased appetite, general physical health deterioration, hypoalbuminemia) and 1 crossover patient (cerebral hemorrhage) experienced TEAEs with an outcome of death, all considered unrelated to study treatment per Investigator. Conclusions: This final safety analysis from the MAVORIC study in patients with previously treated MF and SS demonstrates that moga was generally well tolerated. Longer follow-up and treatment exposure did not identify any new safety signals. The type and incidence of treatment-related AEs among patients receiving moga after crossover were similar to those observed for patients initially randomized to moga. Disclosures Kim: Merck: Research Funding; Portola Pharmaceuticals: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Horizon: Research Funding; Corvus: Honoraria, Membership on an entity's Board of Directors or advisory committees; Galderma: Research Funding; Elorac: Research Funding; Soligenix: Research Funding; Kyowa Hakko Kirin: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Eisai: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Forty Seven Inc: Research Funding; Seattle Genetics: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Medivir: Honoraria, Membership on an entity's Board of Directors or advisory committees; Innate Pharma: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Trillium: Research Funding; Neumedicine: Research Funding; miRagen: Research Funding. Bagot:Innate Pharma: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding. Zinzani:MSD: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Eusapharma: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Sanofi: Consultancy; Celltrion: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Gilead: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Janssen-Cilag: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; BMS: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Servier: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Sandoz: Membership on an entity's Board of Directors or advisory committees; Immune Design: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Celgene: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Portola: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Roche: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Kyowa Kirin: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; TG Therapeutics: Honoraria, Speakers Bureau; Verastem: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Duvic:Seattle Genetics: Consultancy, Honoraria, Research Funding; Eisai: Research Funding; Shape: Research Funding; UT MD Anderson Cancer Center: Employment; USCLC Registry: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Secretary/treasurer of Item h; Spatz Foundation: Research Funding; Tetralogic: Research Funding; Millennium (formerly Takeda): Research Funding; Mallinckrodt Pharmaceuticals (formeraly Therakos, Inc): Research Funding; Kyowa Hakko Kirin Co., Ltd.: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Forty Seven Inc: Membership on an entity's Board of Directors or advisory committees; Cutaneous Lymphoma Foundation: Membership on an entity's Board of Directors or advisory committees; PleXus Communications: Speakers Bureau; Guidepoint Global: Consultancy; Evidera, Inc.: Consultancy; Cell Medica Inc.: Consultancy; Allos: Research Funding; Rhizen Pharma: Research Funding; Oncoceuticals: Research Funding; Soligenetics: Research Funding; Cell Medica Ltd.: Honoraria; Therakos: Speakers Bureau; Jonathan Wood & Assoc.: Speakers Bureau; Hawaiian Dermatology Society: Speakers Bureau; Hemedicus: Speakers Bureau; Janssen Pharmaceuticals (div of Johnson & Johnson): Speakers Bureau. Morris:Guys Hospital: Employment. Kim:Medimmune: Research Funding; Soligenix: Research Funding; Kyowa Kirin: Research Funding; Galderma: Consultancy, Research Funding; Actelion: Consultancy, Research Funding. Musiek:Menlo: Other: Investigator; Helsinn: Membership on an entity's Board of Directors or advisory committees; Soligenix: Other: Investigator; Pfizer: Other: Investigator; Elorac: Other: Investigator; Kyowa: Honoraria, Other: Above honoraria: for Ad Board; miRagen: Other: Investigator. Ortiz-Romero:Actelion: Consultancy, Membership on an entity's Board of Directors or advisory committees; Kyowa: Membership on an entity's Board of Directors or advisory committees; Takeda: Membership on an entity's Board of Directors or advisory committees; PLCG1: Patents & Royalties; miRagen: Membership on an entity's Board of Directors or advisory committees; MEDA: Research Funding; Innate Pharma: Membership on an entity's Board of Directors or advisory committees; 4SC: Membership on an entity's Board of Directors or advisory committees. Eradat:Kyowa: Research Funding; Kite: Research Funding; Pharmacyclics: Consultancy, Honoraria, Research Funding, Speakers Bureau; Roche: Research Funding; Genentech: Consultancy, Honoraria, Research Funding, Speakers Bureau; AbbVie: Consultancy, Honoraria, Research Funding, Speakers Bureau; Gilead: Research Funding. Magnolo:University Hospital of Muenster, Center of Innovative Dermatology: Employment. Scarisbrick:Kyowa Kirin: Consultancy, Membership on an entity's Board of Directors or advisory committees; Takeda: Consultancy, Membership on an entity's Board of Directors or advisory committees; Recordat: Consultancy; 4SC: Consultancy, Membership on an entity's Board of Directors or advisory committees; Innate Pharma: Consultancy, Membership on an entity's Board of Directors or advisory committees; Helsinn: Consultancy, Membership on an entity's Board of Directors or advisory committees. Dalle:Kyowa: Other: Principal Investigator in clinical trials promoted by Kyowa. Fisher:Kyowa Kirin: Consultancy. Poligone:Stemline Therapeutics: Consultancy, Speakers Bureau; Regeneron: Consultancy, Speakers Bureau; Actelion: Consultancy, Speakers Bureau; Astex Pharmaceuticals: Research Funding; Bioniz: Research Funding; Celgene: Consultancy; Helsinn: Research Funding, Speakers Bureau; Innate Pharma: Research Funding; Kyowa Hakko Kirin: Consultancy, Honoraria, Research Funding, Speakers Bureau; miRagen: Research Funding; Soligenix: Research Funding. Pro:Takeda: Consultancy, Honoraria, Other: Travel Expenses; Celgene: Consultancy, Honoraria; Kyowa Hakka Kirin: Consultancy, Honoraria; Seattle Genetics: Consultancy, Honoraria, Other: Travel Expenses, Research Funding. Quaglino:Actelion: Honoraria, Other: Advisory Board; Innate Pharma: Honoraria, Other: Advisory Board; Takeda: Honoraria, Other: Advisory Board; Kyowa Kirin: Honoraria, Other: Advisory Board; Helsinn: Honoraria, Other: Advisory Board; Therakos: Honoraria, Other: Advisory Board. Reddy:AbbVie: Honoraria; Janssen: Honoraria; KITE: Honoraria; Merck: Research Funding; Celgene: Honoraria, Speakers Bureau. Geskin:Merck: Other: Supported/Contracted Research; UpToDate: Patents & Royalties: Royalty, Receipt of Intellectual Property Rights / Patent Holder; Actelion: Other: Supported/Contracted Research; Helsinn: Consultancy, Honoraria, Other: Supported/Contracted Research; Stratpharma: Other: Supported/Contracted Research; Mallinckrodt: Consultancy, Honoraria, Other: Supported/Contracted Research; Medscape: Speakers Bureau; Medivir: Consultancy, Honoraria. Halwani:Amgen: Other: Investigator; Takeda: Other: PI; Seattle Genetics: Other: PI; Pharmacyclics: Other: Investigator; miRagen: Other: PI; Kyowa Hakko Kirin: Other: PI; Immune Design: Other: PI; Genentech, Inc.: Other: Investigator; Bristol-Myers Squibb: Other: PI; AbbVie: Other: PI. Khot:Peter MacCallum Cancer Centre: Employment; Amgen: Consultancy, Speakers Bureau; Celgene: Consultancy; Janssen: Consultancy; Kyowa Hakko Kirin: Consultancy. Korman:Genentech: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Dermira: Research Funding; Glaxo: Honoraria, Membership on an entity's Board of Directors or advisory committees; Immune Pharma: Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Kyowa: Research Funding; Leo: Research Funding; Menlo: Research Funding; Merck: Research Funding; Novartis: Consultancy, Honoraria, Speakers Bureau; Pfizer: Research Funding; Principia: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Prothena: Research Funding; Regeneron: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Rhizen: Research Funding; Sun: Honoraria, Membership on an entity's Board of Directors or advisory committees; Syntimmune: Research Funding; UCB: Research Funding; Valeant: Honoraria, Membership on an entity's Board of Directors or advisory committees; Eli Lilly: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Bristol-Myers Squibb: Research Funding; AbbVie: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Horwitz:Seattle Genetics: Consultancy, Research Funding; Affimed: Consultancy; Astex: Consultancy; Portola: Consultancy; ADCT Therapeutics: Research Funding; Kyowa Hakko Kirin: Consultancy; Infinity/Verastem: Consultancy, Research Funding; Miragen: Consultancy; Seattle Genetics: Consultancy, Research Funding; Forty-Seven: Research Funding; Celgene: Consultancy, Research Funding; Millennium/Takeda: Consultancy, Research Funding; Miragen: Consultancy; Innate Pharma: Consultancy; Kura: Consultancy; Corvus Pharmaceuticals: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Miragen: Consultancy; Infinity/Verastem: Consultancy, Research Funding; Millennium/Takeda: Consultancy, Research Funding; Portola: Consultancy; Kura: Consultancy; Celgene: Consultancy, Research Funding; Kura: Consultancy; Kyowa Hakko Kirin: Consultancy; Infinity/Verastem: Consultancy, Research Funding; Forty-Seven: Research Funding; Trillium: Research Funding; Corvus Pharmaceuticals: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Consultancy, Research Funding; Astex: Consultancy; Affimed: Consultancy; ADCT Therapeutics: Research Funding; Aileron: Research Funding; Corvus Pharmaceuticals: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Kyowa Hakko Kirin: Consultancy; Trillium: Research Funding; Millennium/Takeda: Consultancy, Research Funding; Mundipharma: Consultancy; Millennium/Takeda: Consultancy, Research Funding; Kyowa Hakko Kirin: Consultancy; Portola: Consultancy; Aileron: Research Funding; Mundipharma: Consultancy; Celgene: Consultancy, Research Funding; Mundipharma: Consultancy; Seattle Genetics: Consultancy, Research Funding; ADCT Therapeutics: Research Funding; Portola: Consultancy; Kura: Consultancy; ADCT Therapeutics: Research Funding; Corvus Pharmaceuticals: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Infinity/Verastem: Consultancy, Research Funding; Aileron: Research Funding; Affimed: Consultancy; Trillium: Research Funding; Innate Pharma: Consultancy; Affimed: Consultancy; Astex: Consultancy; Mundipharma: Consultancy; Aileron: Research Funding; Miragen: Consultancy; Trillium: Research Funding; Innate Pharma: Consultancy; Forty-Seven: Research Funding; Forty-Seven: Research Funding; Innate Pharma: Consultancy; Astex: Consultancy; Seattle Genetics: Consultancy, Research Funding. Lamar:Seattle Genetics: Consultancy; Kyowa: Consultancy, Membership on an entity's Board of Directors or advisory committees. Moskowitz:Cell Medica: Consultancy; ADC Therapeutics: Consultancy; Merck: Research Funding; Erytech Pharma: Consultancy; Takeda Pharmaceuticals: Consultancy; Erytech Pharma: Consultancy; Merck: Research Funding; Kyowa Hakko Kirin Pharma: Consultancy, Research Funding; Erytech Pharma: Consultancy; Incyte: Research Funding; Kyowa Hakko Kirin Pharma: Consultancy, Research Funding; Merck: Research Funding; Erytech Pharma: Consultancy; ADC Therapeutics: Consultancy; ADC Therapeutics: Consultancy; Bristol-Myers Squibb: Consultancy, Research Funding; Bristol-Myers Squibb: Consultancy, Research Funding; Erytech Pharma: Consultancy; Bristol-Myers Squibb: Consultancy, Research Funding; miRagen Therapeutics Inc: Consultancy, Research Funding; Kyowa Hakko Kirin Pharma: Consultancy, Research Funding; Takeda Pharmaceuticals: Consultancy; Seattle Genetics: Consultancy, Honoraria, Research Funding; Cell Medica: Consultancy; Erytech Pharma: Consultancy; Seattle Genetics: Consultancy, Honoraria, Research Funding; Cell Medica: Consultancy; Merck: Research Funding; Kyowa Hakko Kirin Pharma: Consultancy, Research Funding; ADC Therapeutics: Consultancy; Merck: Research Funding; Cell Medica: Consultancy; Cell Medica: Consultancy; ADC Therapeutics: Consultancy; Incyte: Research Funding; Takeda Pharmaceuticals: Consultancy; Seattle Genetics: Consultancy, Honoraria, Research Funding; Cell Medica: Consultancy; Cell Medica: Consultancy; miRagen Therapeutics Inc: Consultancy, Research Funding; Bristol-Myers Squibb: Consultancy, Research Funding; Bristol-Myers Squibb: Consultancy, Research Funding; miRagen Therapeutics Inc: Consultancy, Research Funding; Erytech Pharma: Consultancy; miRagen Therapeutics Inc: Consultancy, Research Funding; Incyte: Research Funding; Incyte: Research Funding; miRagen Therapeutics Inc: Consultancy, Research Funding; miRagen Therapeutics Inc: Consultancy, Research Funding; Bristol-Myers Squibb: Consultancy, Research Funding; Kyowa Hakko Kirin Pharma: Consultancy, Research Funding; Bristol-Myers Squibb: Consultancy, Research Funding; Merck: Research Funding; Seattle Genetics: Consultancy, Honoraria, Research Funding; Kyowa Hakko Kirin Pharma: Consultancy, Research Funding; ADC Therapeutics: Consultancy; Merck: Research Funding; ADC Therapeutics: Consultancy; Bristol-Myers Squibb: Consultancy, Research Funding; Merck: Research Funding; Bristol-Myers Squibb: Consultancy, Research Funding; Cell Medica: Consultancy; Seattle Genetics: Consultancy, Honoraria, Research Funding; Seattle Genetics: Consultancy, Honoraria, Research Funding; Bristol-Myers Squibb: Consultancy, Research Funding; Bristol-Myers Squibb: Consultancy, Research Funding; Bristol-Myers Squibb: Consultancy, Research Funding; Incyte: Research Funding; Takeda Pharmaceuticals: Consultancy; Takeda Pharmaceuticals: Consultancy; Cell Medica: Consultancy; Cell Medica: Consultancy; Cell Medica: Consultancy; Incyte: Research Funding; Incyte: Research Funding; Erytech Pharma: Consultancy; ADC Therapeutics: Consultancy; Erytech Pharma: Consultancy; Erytech Pharma: Consultancy; Erytech Pharma: Consultancy; Bristol-Myers Squibb: Consultancy, Research Funding; Erytech Pharma: Consultancy; Erytech Pharma: Consultancy; Seattle Genetics: Consultancy, Honoraria, Research Funding; Kyowa Hakko Kirin Pharma: Consultancy, Research Funding; Merck: Research Funding; Takeda Pharmaceuticals: Consultancy; Merck: Research Funding; Seattle Genetics: Consultancy, Honoraria, Research Funding; Merck: Research Funding; Seattle Genetics: Consultancy, Honoraria, Research Funding; Seattle Genetics: Consultancy, Honoraria, Research Funding; miRagen Therapeutics Inc: Consultancy, Research Funding; Incyte: Research Funding; Seattle Genetics: Consultancy, Honoraria, Research Funding; Merck: Research Funding; Seattle Genetics: Consultancy, Honoraria, Research Funding; Bristol-Myers Squibb: Consultancy, Research Funding; miRagen Therapeutics Inc: Consultancy, Research Funding; ADC Therapeutics: Consultancy; miRagen Therapeutics Inc: Consultancy, Research Funding; Kyowa Hakko Kirin Pharma: Consultancy, Research Funding; Takeda Pharmaceuticals: Consultancy; Takeda Pharmaceuticals: Consultancy; Kyowa Hakko Kirin Pharma: Consultancy, Research Funding; Takeda Pharmaceuticals: Consultancy; ADC Therapeutics: Consultancy; ADC Therapeutics: Consultancy; Incyte: Research Funding; Seattle Genetics: Consultancy, Honoraria, Research Funding; ADC Therapeutics: Consultancy; Incyte: Research Funding; Cell Medica: Consultancy; Incyte: Research Funding; Takeda Pharmaceuticals: Consultancy; Incyte: Research Funding; Takeda Pharmaceuticals: Consultancy; Takeda Pharmaceuticals: Consultancy; Takeda Pharmaceuticals: Consultancy; Cell Medica: Consultancy; Cell Medica: Consultancy; Kyowa Hakko Kirin Pharma: Consultancy, Research Funding; Cell Medica: Consultancy; miRagen Therapeutics Inc: Consultancy, Research Funding; miRagen Therapeutics Inc: Consultancy, Research Funding; Takeda Pharmaceuticals: Consultancy; Incyte: Research Funding; miRagen Therapeutics Inc: Consultancy, Research Funding; Erytech Pharma: Consultancy; miRagen Therapeutics Inc: Consultancy, Research Funding; Kyowa Hakko Kirin Pharma: Consultancy, Research Funding; Kyowa Hakko Kirin Pharma: Consultancy, Research Funding; Kyowa Hakko Kirin Pharma: Consultancy, Research Funding; Merck: Research Funding; miRagen Therapeutics Inc: Consultancy, Research Funding; Incyte: Research Funding; miRagen Therapeutics Inc: Consultancy, Research Funding; Incyte: Research Funding; Takeda Pharmaceuticals: Consultancy; ADC Therapeutics: Consultancy; ADC Therapeutics: Consultancy; ADC Therapeutics: Consultancy; Erytech Pharma: Consultancy; Seattle Genetics: Consultancy, Honoraria, Research Funding; Bristol-Myers Squibb: Consultancy, Research Funding; Seattle Genetics: Consultancy, Honoraria, Research Funding; Kyowa Hakko Kirin Pharma: Consultancy, Research Funding; Merck: Research Funding; Merck: Research Funding; Kyowa Hakko Kirin Pharma: Consultancy, Research Funding. Wells:Takeda Pharmaceuticals Australia Pty Limited: Membership on an entity's Board of Directors or advisory committees; MSD Australia: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Akilov:Trillium Therapeutics: Consultancy, Other: PI on the clinical trials, Research Funding; Pfizer: Research Funding. Cowan:Kyowa Kirin: Consultancy. Dummer:Merck Sharp & Dohme: Other: Intermittent, project focused consulting and/or advisory relationships; Novartis: Other: Intermittent, project focused consulting and/or advisory relationships; Bristol-Myers Squibb: Other: Intermittent, project focused consulting and/or advisory relationships; Roche: Other: Intermittent, project focused consulting and/or advisory relationships; Amgen: Other: Intermittent, project focused consulting and/or advisory relationships; Takeda: Other: Intermittent, project focused consulting and/or advisory relationships; Pierre Fabre: Other: Intermittent, project focused consulting and/or advisory relationships; Sun Pharma: Other: Intermittent, project focused consulting and/or advisory relationships; Sanofi: Other: Intermittent, project focused consulting and/or advisory relationships; Catalym: Other: Intermittent, project focused consulting and/or advisory relationships; Second Genome: Other: Intermittent, project focused consulting and/or advisory relationships. Lechowicz:Kyowa Kirin Inc: Consultancy; Spectrum: Consultancy. Foss:Eisai: Consultancy; Seattle Genetics: Consultancy, Other: fees for non-CME/CE services ; miRagen: Consultancy; Acrotech: Consultancy; Mallinckrodt: Consultancy; Spectrum: Other: fees for non-CME/CE services . Wilcox:University of Michigan: Employment. Porcu:Innate Pharma: Honoraria, Other: Scientific Board, Research Funding; Viracta: Honoraria, Other: Scientific Board, Research Funding; BeiGene: Other: Scientific Board, Research Funding; Incyte: Research Funding; Daiichi: Research Funding; Kyowa: Honoraria, Other: Scientific Board, Research Funding; ADCT: Research Funding; Spectrum: Consultancy. Vermeer:Kyowa: Membership on an entity's Board of Directors or advisory committees, Research Funding; Takeda: Membership on an entity's Board of Directors or advisory committees, Research Funding. Abhyankar:Therakos: Other: Consulting, Speakers Bureau; Incyte: Speakers Bureau. Pacheco:University of Colorado: Employment. William:Techspert: Consultancy; Guidepoint Global: Consultancy; Defined Health: Consultancy; Celgene Corporation: Consultancy; Kyowa Kirin, Inc.: Consultancy. Fukuhara:Kyowa-Hakko Kirin: Honoraria; Bayer: Research Funding; Mundi: Honoraria; Janssen Pharma: Honoraria; Mochida: Honoraria; Ono Pharmaceutical Co., Ltd.: Honoraria; Takeda Pharmaceutical Co., Ltd.: Honoraria, Research Funding; Chugai Pharmaceutical Co., Ltd.: Honoraria; Eisai: Honoraria, Research Funding; Celgene Corporation: Honoraria, Research Funding; Nippon Shinkyaku: Honoraria; Zenyaku: Honoraria; AbbVie: Research Funding; Gilead: Research Funding; Solasia Pharma: Research Funding. Munoz:Pharmacyclics /Janssen: Consultancy, Research Funding, Speakers Bureau; Bayer: Consultancy, Speakers Bureau; Merck: Consultancy; Kyowa: Consultancy, Honoraria, Speakers Bureau; Seattle Genetics: Consultancy, Honoraria, Research Funding, Speakers Bureau; Celgene/Juno: Consultancy, Research Funding; Genentech: Consultancy, Research Funding, Speakers Bureau; Fosunkite: Speakers Bureau; AstraZeneca: Speakers Bureau; Portola: Research Funding; Incyte: Research Funding; Kite/Gilead: Consultancy, Research Funding, Speakers Bureau; Bristol-Myers Squibb: Consultancy; Alexion: Consultancy; Pfizer: Consultancy. Querfeld:Elorac: Other: Investigator, Research Funding; Trillium: Consultancy, Other: Investigator, Research Funding; Medivir: Consultancy; miRagen: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Investigator; Helsinn: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Investigator; Soligenix: Other: Investigator; City of Hope Cancer Center and Beckman Research Institute: Employment; Celgene: Other: Investigator, Research Funding; Kyowa: Membership on an entity's Board of Directors or advisory committees, Other: Investigator; Eisai: Other: Investigator; Bioniz: Membership on an entity's Board of Directors or advisory committees, Other: Investigator. Uhara:Kyowa Kirin Co., Ltd: Honoraria, Research Funding. Huen:Innate Pharmaceuticals: Research Funding; Galderma Inc: Research Funding; Rhizen Pharmaceuticals: Research Funding; Glaxo Smith Kline Inc: Research Funding. Tobinai:Meiji Seika: Honoraria; Takeda Pharmaceutical: Consultancy, Honoraria, Research Funding; Daiichi Sankyo: Consultancy, Honoraria; Janssen Pharmaceutical: Honoraria, Research Funding; Kyowa Kirin: Honoraria, Research Funding; Ono Pharmaceutical: Consultancy, Honoraria, Research Funding; Zenyaku Kogyo: Consultancy, Honoraria; Celgene: Consultancy, Honoraria, Research Funding; Mundi Pharma: Consultancy, Honoraria, Research Funding; Eisai: Honoraria, Research Funding; HUYA Bioscience: Consultancy, Honoraria; Bristol-Myers Squibb: Honoraria; AbbVie: Research Funding; Verastem: Honoraria; Chugai Pharmaceutical: Honoraria, Research Funding; Yakult: Honoraria; Solasia: Honoraria. Tokura:Kyowa Kirin Pharmaceutical Development, Inc.: Honoraria. Boh:Actelion: Other: Principal Investigator; Tulane University School of Medicine: Employment; Celgene: Other: Principal Investigator, Speaker, Grants; Sun: Other: Speaker; Janssen: Other: Principal Investigator, Speaker, Grants; Novartis: Other: Principal Investigator, Speaker, Grants; Soligenix: Other: Principal Investigator; Incyte: Other: Principal Investigator; Regeneron: Other: Principal Investigator, Grants; Ortho Dermatologics: Other: Speaker, Grants; Pfizer: Other: Principal Investigator; UCB: Other: Speaker, Grants; Elorac: Other: Principal Investigator; Abbvie: Other: Principal Investigator. Nicolay:Teva Pharmaceutical Industries: Honoraria, Other: Conference participation fees; Novartis AG: Consultancy, Honoraria; Biogen GmbH: Consultancy, Honoraria; Almirall Hermal AG: Consultancy, Honoraria; Actelion Pharmaceuticals: Consultancy, Honoraria; Innate Pharma: Consultancy; Kyowa Hakko Kirin: Consultancy, Honoraria; Takeda Pharmaceuticals: Consultancy. Leoni:Kyowa Kirin Pharmaceutical Development, Inc.: Employment. Ito:Kyowa Kirin Pharmaceutical Development, Inc.: Employment. Herr:Kyowa Kirin, Inc.: Employment. Sokol:EUSA: Consultancy.

Background: Patients with follicular lymphoma (FL) have a heterogenous prognosis. Recently a simple score, the PRIMA-PI, was developed based on the PRIMA clinical trial (Bachy et al Blood. 2018). With only two factors (beta-2-microglobulin level > 3 mg/L and bone marrow involvement), this index was at least as discriminatory as FLIPI on the training and validation cohorts. The validity of the PRIMA-PI was confirmed on Czech and German FL cohorts and a patient group from the Nordic Lymphoma Group. However, further validation is needed to confirm the use of PRIMA-PI in place of FLIPI for prognostic assessment. Indeed, in the era of new chemo-free treatments, it seems important to challenge the potency of traditional prognostic factors and scores. Recently, rituximab combined with lenalidomide (R2) was compared to conventional immunochemotherapy (R-chemo) in the phase III RELEVANCE trial. The aim of our study was to validate PRIMA-PI in the RELEVANCE trial cohort and compare its performance with FLIPI (Solal-Celigny et al. Blood. 2004) and FLIPI2 (Federico et al. JCO. 2009). A secondary objective was to evaluate potential differences in terms of prognostic bio-clinical parameters between the R2 and R-chemo arms. Methods: All patients with available data for FLIPI, FLIPI2, and PRIMA-PI from the intention to treat population of the RELEVANCE study were included in the analysis. PFS according to each prognostic score were assessed in the total population and by treatment arms. Data were not mature enough to compare OS distributions. Performance metrics (log-rank p value and Net Reclassification Improvement [NRI]) were calculated for each group to assess concordance and discriminating ability of each score. Results: Median follow-up time for the study was 38 months. Overall, 846 RELEVANCE patients were included in the analysis. Data were available for 845 patients for FLIPI score assessment, 832 for FLIPI2 and 807 for PRIMA-PI. Group repartition according to the FLIPI and the FLIPI2 were largely imbalanced compared with PRIMA-PI. FLIPI classified very few patients in the low risk group (15% LR) while 49% of the patients were at high risk (HR), and 36% were at intermediate risk (IR). Similarly, FLIPI2 risk categories were as follow: 8% LR, 50% IR, and 42% HR. On the contrary, PRIMA-PI divided the study population into three equal groups (33%, 33% and 34%). In the total population, FLIPI and PRIMA-PI were predictive of PFS (p=0.029 and p=0.004, respectively); FLIPI2 showed poor performance (p=0.094). PFS curves based on each score are shown in Figure 1. NRI index indicated that the PRIMA-PI yielded analogous segregation for PFS with FLIPI (NRI 0.16; 95% CI: -0.008, 0.318; Table 1). In the R-chemo arm, both FLIPI and PRIMA-PI could isolate different prognostic groups for PFS, whereas FLIPI2 could not. Conversely, none of the indices were able to significantly discriminate outcomes for patients treated with R2. Interestingly, analysis showed that some usual prognostic factors, especially those likely to reflect tumor burden such as beta-2 microglobulin and LDH, were not predictive for PFS in the R2 arm. In contrast, low albumin ( Conclusion: For patients with FL treated upfront with immunochemotherapy, the PRIMA-PI is a valid scoring system that allows to segregate patients as efficiently as the FLIPI while using only two factors. These results confirm that the PRIMA-PI could substitute for the FLIPI for patients treated with upfront R-chemo. Athough our data have to be interpreted in light of the short median follow-up time, they also suggest that other clinical/biological parameters might be considered and new prognostic indexes established for patients treated with R2. Considering possible mechanisms of action of lenalidomide, prognostic factors related to the underlying patient's immunological status might be more predictive. Disclosures Fowler: Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding; TG Therapeutics: Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis Pharmaceuticals Corporation: Consultancy; ABBVIE: Membership on an entity's Board of Directors or advisory committees, Research Funding; Roche: Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding. Bachy:Roche: Consultancy; Janssen Cilag: Honoraria; Gilead Science: Honoraria; Amgen: Honoraria; Roche: Honoraria; Janssen Cilag: Other: Travel, accomodation, Expense. Feugier:abbvie: Honoraria, Research Funding, Speakers Bureau; roche: Honoraria, Research Funding, Speakers Bureau; janssen: Honoraria, Research Funding, Speakers Bureau; gilead: Honoraria, Research Funding, Speakers Bureau. Tilly:roche: Membership on an entity's Board of Directors or advisory committees; servier: Honoraria; merck: Honoraria; Gilead: Honoraria; Janssen: Honoraria; BMS: Honoraria; Karyopharm: Consultancy; Astra-Zeneca: Consultancy; Roche: Consultancy; Celgene: Consultancy, Research Funding. Palomba:Pharmacyclics: Membership on an entity's Board of Directors or advisory committees; Noble Insights: Consultancy; Evelo: Other: Immediate family member, Equity Ownership; MSK (IP for Juno and Seres): Other: Immediate Family Member, Patents & Royalties - describe: intellectual property rights ; Hemedicus: Other: Immediate Family Member, Speakers Bureau ; Merck & Co Inc.: Other: Immediate Family Member, Consultancy (includes expert testimony); Seres Therapeutics: Other: Immediate Family Member, Equity Ownership and Membership on an entity's Board of Directors or advisory committees; STRAXIMM: Other: Immediate Family Member, Membership on an entity's Board of Directors or advisory committees; Kite Pharmaceuticals: Other: Immediate Family Member, Membership on an entity's Board of Directors or advisory committees. Libby:Akcea: Consultancy; Alnylam: Consultancy; Abbvie: Consultancy; Pharmacyclics and Janssen: Consultancy. Casasnovas:Merck Sharp and Dohme: Membership on an entity's Board of Directors or advisory committees, Other: Travel support, Research Funding; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel support; Abbvie: Honoraria, Membership on an entity's Board of Directors or advisory committees; Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Roche: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Gilead: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Gilead: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Bristol-Myers Squibb: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel expenses. Flinn:TG Therapeutics, Trillum Therapeutics, Abbvie, ArQule, BeiGene, Curis, FORMA Therapeutics, Forty Seven, Merck, Pfizer, Takeda, Teva, Verastem, Gilead Sciences, Astra Zeneca (AZ), Juno Therapeutics, UnumTherapeutics, MorphoSys, AG: Research Funding; F. Hoffmann-La Roche Ltd: Research Funding; TG Therapeutics, Trillum Therapeutics, Abbvie, ArQule, BeiGene, Curis, FORMA Therapeutics, Forty Seven, Merck, Pfizer, Takeda, Teva, Verastem, Gilead Sciences, Astra Zeneca (AZ), Juno Therapeutics, UnumTherapeutics, MorphoSys, AG: Research Funding; AbbVie, Seattle Genetics, TG Therapeutics, Verastem: Consultancy; Acerta Pharma, Agios, Calithera Biosciences, Celgene, Constellation Pharmaceuticals, Genentech, Gilead Sciences, Incyte, Infinity Pharmaceuticals, Janssen, Karyopharm Therapeutics, Kite Pharma, Novartis, Pharmacyclics, Portola Pharmaceuticals: Research Funding. Haioun:Novartis: Honoraria; Janssen: Honoraria; F. Hoffmann-La Roche Ltd: Honoraria; Servier: Honoraria; Takeda: Honoraria; Miltenyi: Honoraria; Gilead: Honoraria; Celgene: Honoraria; Amgen: Honoraria. Bartlett:Pharmacyclics: Research Funding; Pfizer: Research Funding; Affimed: Research Funding; Celgene: Research Funding; Millenium: Research Funding; Merck: Research Funding; Seattle Genetics: Research Funding; Forty Seven: Research Funding; Bristol-Myers Squibb: Research Funding; ADC Therapeutics: Consultancy, Research Funding; Genenetech: Research Funding; Gilead: Research Funding; Immune Design: Research Funding; Janssen: Research Funding. Bouabdallah:Takeda: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Roche: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees. Brice:BMS: Honoraria; Millennium Takeda: Research Funding; Takeda France: Consultancy, Honoraria. Ribrag:Nanostring: Membership on an entity's Board of Directors or advisory committees; Servier: Consultancy, Membership on an entity's Board of Directors or advisory committees; Epizyme: Consultancy, Research Funding; ArgenX: Research Funding; Roche: Other: Travel, accommodations, and expenses ; BMS: Membership on an entity's Board of Directors or advisory committees, Other: Travel, accommodations, and expenses ; MSD: Membership on an entity's Board of Directors or advisory committees; Incyte: Membership on an entity's Board of Directors or advisory committees; Gilead: Membership on an entity's Board of Directors or advisory committees; Infinity: Membership on an entity's Board of Directors or advisory committees; AZ: Membership on an entity's Board of Directors or advisory committees. Le Gouill:Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel support; Roche-Genentech: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel support. Martín:Teva: Research Funding; Gilead: Consultancy, Honoraria; Kiowa Kirin: Consultancy; Roche: Consultancy, Honoraria, Other: Travel Expenses; iQone: Consultancy; Servier: Honoraria, Other: Travel Expenses; Janssen: Honoraria, Other: Travel Expenses, Research Funding; Celgene: Consultancy, Honoraria, Other: Travel Expenses, Research Funding. Lopez-Guillermo:Roche: Consultancy, Research Funding; Gilead: Consultancy, Research Funding; Celgene: Consultancy, Research Funding; Janssen: Research Funding. Larouche:Bayer; Gilead Sciences; Merck; Roche: Research Funding. Ando:Eisai: Research Funding. Maria:Janssen Cilag: Consultancy, Other: Travel support; Gilead Sciences: Other: Travel support, Research Funding; Abbvie: Consultancy, Other: Travel support; Celgene: Consultancy; Roche: Consultancy, Other: Travel support. André:Takeda: Membership on an entity's Board of Directors or advisory committees; Bristol-Myers-Squibb: Membership on an entity's Board of Directors or advisory committees; Karyopharm: Membership on an entity's Board of Directors or advisory committees; Gilead: Membership on an entity's Board of Directors or advisory committees, Other: Travel grants; Novartis: Membership on an entity's Board of Directors or advisory committees, Research Funding; Seattle Genetics: Membership on an entity's Board of Directors or advisory committees; Abbvie: Membership on an entity's Board of Directors or advisory committees; Roche: Other: Travel grants, Research Funding; Amgen: Other: Travel grants, Research Funding; Johnson & Johnson: Research Funding; Takeda Millenium: Research Funding; Chugai: Research Funding; Celgene: Other: Travel grants, Research Funding. Sehn:Merck: Consultancy, Honoraria; Acerta: Consultancy, Honoraria; TEVA Pharmaceuticals Industries: Consultancy, Honoraria; F. Hoffmann-La Roche/Genentech: Consultancy, Honoraria, Research Funding; TEVA Pharmaceuticals Industries: Consultancy, Honoraria; Seattle Genetics: Consultancy, Honoraria; Astra Zeneca: Consultancy, Honoraria; Lundbeck: Consultancy, Honoraria; Kite Pharma: Consultancy, Honoraria; Kite Pharma: Consultancy, Honoraria; Astra Zeneca: Consultancy, Honoraria; Acerta: Consultancy, Honoraria; Morphosys: Consultancy, Honoraria; Janssen-Ortho: Honoraria; Janssen-Ortho: Honoraria; F. Hoffmann-La Roche/Genentech: Consultancy, Honoraria, Research Funding; Merck: Consultancy, Honoraria; TG Therapeutics: Consultancy, Honoraria; TG Therapeutics: Consultancy, Honoraria; Lundbeck: Consultancy, Honoraria; Amgen: Consultancy, Honoraria; Amgen: Consultancy, Honoraria; Abbvie: Consultancy, Honoraria; Seattle Genetics: Consultancy, Honoraria; Abbvie: Consultancy, Honoraria; Morphosys: Consultancy, Honoraria. Tobinai:Daiichi Sankyo: Consultancy, Honoraria; Eisai: Honoraria, Research Funding; Verastem: Honoraria; Mundi Pharma: Consultancy, Honoraria, Research Funding; Zenyaku Kogyo: Consultancy, Honoraria; Yakult: Honoraria; Janssen Pharmaceutical: Honoraria, Research Funding; Celgene: Consultancy, Honoraria, Research Funding; HUYA Bioscience: Consultancy, Honoraria; Ono Pharmaceutical: Consultancy, Honoraria, Research Funding; Chugai Pharmaceutical: Honoraria, Research Funding; AbbVie: Research Funding; Solasia: Honoraria; Meiji Seika: Honoraria; Kyowa Kirin: Honoraria, Research Funding; Bristol-Myers Squibb: Honoraria; Takeda Pharmaceutical: Consultancy, Honoraria, Research Funding. Cartron:Roche, Celgene: Consultancy; Sanofi, Gilead, Janssen, Roche, Celgene: Honoraria. Delarue:Celgene Corporation: Employment, Equity Ownership. Czuczman:Celgene Corporation: Employment, Equity Ownership. Salles:BMS: Honoraria; Takeda: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Educational events; Autolus: Consultancy, Membership on an entity's Board of Directors or advisory committees; Novartis, Servier, AbbVie, Karyopharm, Kite, MorphoSys: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Educational events; Amgen: Honoraria, Other: Educational events; Epizyme: Consultancy, Honoraria; Roche, Janssen, Gilead, Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Educational events; Merck: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees. Morschhauser:Bayer: Membership on an entity's Board of Directors or advisory committees; Gilead: Membership on an entity's Board of Directors or advisory committees; Epizyme: Membership on an entity's Board of Directors or advisory committees; Janssen: Honoraria; BMS: Membership on an entity's Board of Directors or advisory committees; F. Hoffmann-La Roche Ltd: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees.

Background Although the proteasome inhibitor bortezomib (Btz) shows excellent efficacy in multiple myeloma (MM), some patients exhibit sub-optimal or no response to this agent. In addition, Btz-induced toxicity, such as peripheral neuropathy (PN) and skin disorders, limits its use in some patients. A comprehensive analysis of metabolites (metabolomics) in biofluids can be a potential novel strategy to predict the efficacy or adverse events of Btz treatment. With respect to the metabolic pathways in MM cells, a few studies have applied metabolomics using serum/plasma samples to elucidate MM pathogenesis or the mechanisms underlying the malignant transformation of MM cells. In addition, no metabolomic profile has been examined in terms of efficacy or toxicity of the specific MM treatment. In this study, we performed lipid metabolomics analysis using plasma samples from patients with newly diagnosed MM (NDMM) prior to the initial Btz therapy, and have attempted to identify the association between the level of specific biomarkers in plasma lipid metabolites and the efficacy or severity of Btz-related toxicity. Materials & Methods Fifty-four plasma samples were analyzed from transplant-ineligible patients with NDMM enrolled in a randomized phase II study comparing two less intensive regimens of melphalan, prednisolone, and Btz (MPB) (JCOG1105; UMIN000011180). Informed consent to participate in the JCOG-BioBank, Japan Biorepository project, was obtained from the patients prior to sample acquisition. Frozen plasma samples obtained prior to MPB therapy were subjected to lipid metabolomics analysis, and the levels of phospholipids, sphingolipids, neutral lipids, and fatty acids (FAs) were measured using Liquid Chromatography/Mass spectrometry. The levels of lipid metabolites were relatively quantified as the ion peak ratio of each metabolite to the internal standard. We then evaluated whether the level of each lipid metabolite associated with the depth of response to MPB therapy and the grade of Btz-induced toxicity, such as peripheral neuropathy (PN) and skin disorders. Statistical analysis was performed by a multivariate permutation test using the Welch's t-statistic for multiple comparisons of the metabolite levels between the two groups categorized based on their response to MPB therapy or the grade of toxicity, ie. responder vs non-responder to the therapy, and grade 0-1 vs grade 2 or higher in the toxicities. Results and Discussion Lipid metabolomics analysis detected approximately 485 lipid metabolites in 54 plasma samples. We then evaluated the association between the level of each lipid metabolite and the grade of Btz-induced PN (BiPN) or skin disorders. As shown in Figure 1, high levels of seven phospholipids, including four lysophosphatidylcholine (LPC) and three phosphatidylcholine (PC), were associated with BiPN of grade 2 or higher (n=11). LPC species were reported to facilitate neuropathic pain and nerve demyelination of the dorsal root ganglion and cuneate nucleus in the experimental model of PN. Therefore, high level of plasma LPC might worsen BiPN. Moreover, low levels of three fatty acids-FA (18:2), FA (18:1), and FA (22:6)-were observed in patients who developed severe skin disorders of grade 2 or higher (n=10). Low level of FA (18:2), also called linoleic acid, has been reported to impair the anti-inflammatory response and repair skin barrier during the healing process. Therefore, low level of plasma FA (18:2) might associate with the aggravation of Btz-induced skin disorders. No metabolite was significantly associated with tumor response, such as CR (n=9), in 53 samples evaluated for the best response to MPB therapy. Conclusion To our knowledge, this is the first plasma lipid metabolomics study to demonstrate that plasma lipid metabolite levels are associated with the severity of BiPN and skin disorders in patients with MM. These metabolites may serve as candidate biomarkers to predict Btz-induced toxicity in patients with MM before initiating Btz therapy. Our exploratory results need to be confirmed in further validation studies. Disclosures Ri: Janssen Pharmaceutical: Honoraria, Research Funding; Takeda Pharmaceutical: Honoraria, Research Funding; Celgene: Honoraria, Research Funding; Daiichi Sankyo: Research Funding; Ono Pharmaceutical: Honoraria, Research Funding; Kyowa Kirin: Research Funding; Chugai Pharmaceutical: Research Funding; Sanofi: Honoraria, Research Funding; Abbvie: Research Funding; Bristol-Myers Squibb: Honoraria, Research Funding; MSD: Research Funding; Novartis Pharma: Research Funding; Gilead Sciences: Research Funding; Astellas Pharma: Research Funding; Teijin Pharma: Research Funding. Iida:Celgene: Honoraria, Research Funding; Chugai: Research Funding; Kyowa Kirin: Research Funding; Abbvie: Research Funding; MSD: Research Funding; Novartis: Honoraria, Research Funding; Bristol-Myers Squibb: Honoraria, Research Funding; Teijin Pharma: Research Funding; Janssen: Honoraria, Research Funding; Daichi Sankyo: Honoraria, Research Funding; Takeda: Honoraria, Research Funding; Astellas: Research Funding; Gilead: Research Funding; Sanofi: Research Funding. Maruyama:Eisai: Honoraria, Research Funding. Tohkin:Towa Pharmaceutical: Research Funding. Tobinai:Kyowa Kirin: Honoraria, Research Funding; Meiji Seika: Honoraria; Zenyaku Kogyo: Consultancy, Honoraria; Takeda Pharmaceutical: Consultancy, Honoraria, Research Funding; Verastem: Honoraria; Ono Pharmaceutical: Consultancy, Honoraria, Research Funding; HUYA Bioscience: Consultancy, Honoraria; Janssen Pharmaceutical: Honoraria, Research Funding; Celgene: Consultancy, Honoraria, Research Funding; Bristol-Myers Squibb: Honoraria; Solasia: Honoraria; Chugai Pharmaceutical: Honoraria, Research Funding; Daiichi Sankyo: Consultancy, Honoraria; Eisai: Honoraria, Research Funding; Yakult: Honoraria; Mundi Pharma: Consultancy, Honoraria, Research Funding; AbbVie: Research Funding. Fukuhara:Chugai Pharmaceutical Co., Ltd.: Honoraria; Zenyaku: Honoraria; Eisai: Honoraria, Research Funding; Janssen Pharma: Honoraria; Mochida: Honoraria; Ono Pharmaceutical Co., Ltd.: Honoraria; Takeda Pharmaceutical Co., Ltd.: Honoraria, Research Funding; Mundi: Honoraria; Kyowa-Hakko Kirin: Honoraria; AbbVie: Research Funding; Celgene Corporation: Honoraria, Research Funding; Nippon Shinkyaku: Honoraria; Bayer: Research Funding; Gilead: Research Funding; Solasia Pharma: Research Funding. Miyazaki:Ono Pharmaceutical: Research Funding; Astellas Pharma: Research Funding; Eisai: Honoraria; SymBio Pharmaceuticals: Honoraria; Takeda: Honoraria; Nippon Shinyaku: Honoraria; Celgene: Honoraria; Kyowa Hakko Kirin: Honoraria, Research Funding; Chugai: Honoraria; Janssen Pharmaceutical: Honoraria. Tsujimura:Chugai Pharmaceutical: Honoraria; Eisai: Honoraria; Kyowa Kirin: Honoraria; Takeda Pharmaceutical: Honoraria. Yoshimitsu:Novartis: Speakers Bureau; Bristol-Myer-Squibb,: Speakers Bureau; Shire: Speakers Bureau; Takeda: Speakers Bureau; Chugai: Speakers Bureau; Sanofi: Speakers Bureau. Tsukasaki:Byer: Research Funding; Kyowa Kirin: Honoraria; Mundi Pharma: Honoraria; Ono Pharmaceutical: Consultancy; Daiichi Sankyo: Consultancy; Eisai: Research Funding; Celgene: Honoraria, Research Funding; Huya: Consultancy, Honoraria, Research Funding; Chugai Pharmaceutical: Honoraria, Research Funding. Nagai:SymBio Pharmaceuticals Limited: Honoraria, Research Funding; AstraZeneca: Honoraria, Research Funding; HUYA Bioscience International: Research Funding; Solasia Pharma K.K.: Research Funding; Zenyaku Kogyo: Honoraria, Research Funding; Ono Pharmaceutical: Honoraria, Research Funding; Bristol-Myers Squibb: Honoraria, Research Funding; Eisai: Honoraria, Research Funding; Kyowa Kirin: Honoraria, Research Funding; Takeda Pharmaceutical: Honoraria, Research Funding; AbbVie: Research Funding; Bayer Pharma: Honoraria, Research Funding; Mundi Pharma: Honoraria, Research Funding; Celgene: Honoraria, Research Funding; Janssen Pharmaceutical: Honoraria, Research Funding; Chugai Pharmaceutical: Honoraria, Research Funding; MSD: Honoraria; IQVIA: Research Funding; Otsuka Pharmaceutical: Research Funding; Sanofi: Honoraria; Novartis Pharma: Honoraria.

Introduction: Follicular lymphoma (FL) is an indolent form of non-Hodgkin lymphoma (NHL), which accounts for 20-30% of all NHL cases. In most patients, FL is diagnosed in advance stages, mild disease progression and long treatment period that may incur a great burden to patients and healthcare system. However, to our knowledge there is no comprehensive analysis which have been done in the real world setting in Japan. Therefore, we conducted a retrospective claim database study to elucidate the lines of treatment patterns as well as the associated healthcare resource utilization (HCRU), and 3- and 5-year overall survival (OS) among 3,593 Japanese patients with a median age of 65.0 years. Methods: This retrospective study analyzed data from the Medical Data Vision (MDV) database for patients diagnosed with FL (ICD-10: C82). The MDV database is an electronic health records-based database comprised of anonymized inpatient and outpatient data covering over 25 million patients and over 374 Japanese hospitals, approximately 22% of acute phase hospitals, including 187 cancer therapeutic facilities. Patients who received treatment during the identification period from 1 October 2008 to 31 December 2017 were selected. Patients were required to have data for at least 6 months before the first treatment date (ie, patient index date) and at least 12 months after the index date (unless they died). Costs were converted from Japanese yen to US dollars using the exchange rate based on January of each year of service. For 3- and 5-year OS, patients who had a record of death in their hospital discharge were counted as an event, otherwise they were censored at the latest of: end of patient record, end of data availability, or end of the 3- or 5- year period. Results: A total of 3,593 patients with FL met the inclusion criteria of which 51.2% was female patients. Of these 3,593 patients who met the inclusion criteria, 3,004 patients (83.6%) received rituximab-based (R) therapy as index treatment, of which 1309 (36.4%) of patients received R-CHOP. During the subsequent lines of therapies, patients received heterogeneous treatment regimens (fig 1). Overall, the average healthcare cost during follow-up period was $67,557.40 for all FL patients, ranging from $39,340 (immunotherapy, targeted therapy, or hormone therapy without R) to $ 95,095 (other R-based chemotherapy). The average number of outpatient visits during follow-up for all FL patients was 51, ranging from 44.6 to 55.1 for each treatment group. There were 3,394 (94.5%) patients who had at least one hospitalization during follow up period. Among those who had at least one hospitalization, the average number of hospitalizations was 3.8 for all FL patients, ranging from 2.5 to 4.6 for each treatment group. The average number of days of hospitalization during follow-up was 74.5 for all FL patients, ranging from 31 to 110.4 for each treatment group. 85 (2.4%) FL patients received a stem cell transplant (SCT) during follow-up at the age under 79 years, with other R-based therapies having the highest percentage (7.6%). There were 346 (9.7%) FL patients receiving radiation therapy, ranging from 8.1% (other treatment groups) to 24.1% (immunotherapy, targeted therapy, or hormone therapy without R). There were 337 deaths (9.4%) recorded within 3 years and 400 (11.1%) within 5 years of index treatment. The median Kaplan-Meier OS was not reached for most analysis groups due to the overall high survival rates. When comparing overall survival by index regimen group, chemotherapy without R consistently had worse survival, especially compared to R-based regimens (fig. 2). Conclusions: Patients with FL in Japan received diverse treatment regimens and multiple lines of therapy with relatively high survival rates. Majority of patients have received R-based therapies and have shown longer survival rates compared to those who have received chemotherapy without R. This is the first study to clarify lines of treatment patterns using retrospective claims database and treatment group-based OS in FL patients in Japan, which will give clinical insights of the landscape of daily practices and the associated real world health economic burden for patients, clinicians and healthcare providers to support their better decision makings. Disclosures Tsutsue: Celgene: Employment. Tobinai:Solasia: Honoraria; Mundi Pharma: Consultancy, Honoraria, Research Funding; Takeda Pharmaceutical: Consultancy, Honoraria, Research Funding; Celgene: Consultancy, Honoraria, Research Funding; Ono Pharmaceutical: Consultancy, Honoraria, Research Funding; Yakult: Honoraria; AbbVie: Research Funding; Meiji Seika: Honoraria; Janssen Pharmaceutical: Honoraria, Research Funding; Bristol-Myers Squibb: Honoraria; HUYA Bioscience: Consultancy, Honoraria; Zenyaku Kogyo: Consultancy, Honoraria; Daiichi Sankyo: Consultancy, Honoraria; Eisai: Honoraria, Research Funding; Chugai Pharmaceutical: Honoraria, Research Funding; Verastem: Honoraria; Kyowa Kirin: Honoraria, Research Funding. Yi:Celgene: Consultancy. Crawford:Celgene: Consultancy.

Introduction: Enhancer of zeste homolog 2 (EZH2) and EZH1 are alternative subunits of polycomb repressive complex 2 that catalyze the tri-methylation of lysine 27 residue of histone H3. This histone modification epigenetically regulates gene expression and may play an important role in tumor progression. Valemetostat (DS-3201) is a potent and highly specific orally bioavailable dual inhibitor of EZH2 and EZH1 demonstrating anti-tumor activity against various hematological malignancies in preclinical studies (Honma D, et al. Cancer Sci 2017; Fujita S, et al. Leukemia 2018). Valemetostat demonstrated clinical activity as a novel oral therapeutic option for both B-cell and T-cell NHLs in the interim analysis of a phase I study (Maruyama D, et al. ASH 2017). Here we report the updated results of this phase I study focusing on ATL patients. ATL is a peripheral T-cell malignancy caused by human T-cell leukemia virus type I (HTLV-1), and is divided into aggressive and indolent subtypes. Aggressive ATL has an extremely poor prognosis, with a median survival time of only 8 to 10 months (Katsuya H, et al. Blood 2015). Although conventional chemotherapeutic agents, anti-CCR4 antibody mogamulizmab, and oral immunomodulator lenalidomide have been used for treatment of aggressive ATL patients, most patients eventually become resistant to treatment. In addition, allogenic hematopoietic stem cell transplantation is not available for elderly patients. Therefore, new therapeutic options are urgently needed. Methods: This ongoing open-label, single-arm phase I study consists of the dose escalation part (NHLs including ATL and peripheral T-cell lymphoma [PTCL]) and the expansion part (ATL and PTCL). The drug was administered orally once daily (QD) continuously over 28-days (1 cycle) until disease progression or intolerance. Results: Thirty-eight patients (15 females) with a median age of 69 (44-88) were enrolled in this study as of the data cut-off of 24 January 2019. Of 38 patients, 25 patients were enrolled in the dose-escalation part, and additional 13 patients (7 ATLs and 6 PTCLs) were treated in the expansion part with 200 mg of valemetostat. In all patients, adverse events (≥30%) on treatment with all grades included; platelet count decreased (73.7%), dysgeusia (52.6%), anemia (42.1%), lymphocyte count decreased (39.5%), neutrophil count decreased (39.5%), and white blood cell count decreased (39.5%). Preliminary efficacy was based on investigator's assessment with an objective response rate (ORR) of 47.2%. Fifteen patients were able to stay on valemetostat for more than 24 weeks with tumor shrinkage. Of the 9 ATL patients in the study (2 in dose escalation and 7 in dose expansion), baseline characteristics are as follows: age, median age 74 (range 61-78 yrs); sex, 7 males and 2 females; ATL subtype, 6 acute- and 3 lymphoma-subtypes; median number of prior therapies, 2 (range 1-8). Adverse events (≥30%) on treatment with all grades in the 9 ATL patients included; platelet count decreased (77.8%), dysgeusia (66.7%), neutrophil count decreased (44.4%), white blood cell count decreased (44.4%), anemia (33.3%), alopecia (33.3%), and dry skin (33.3%). No grade 4 and 5 adverse events were detected. Grade 3 adverse events included; white blood cell count decreased (33.3%), platelet count decreased (22.2%), neutrophil count decreased (22.2%), lymphocyte count decreased (11.1%), and anemia (11.1%), which are consistent with those in all population. Responses for the 9 ATL patients included; 1 unconfirmed complete remission (CRu), 3 partial remission (PR), and 3 stable disease (SD) (ORR = 44.4%; 4/9). Of the 6 prior mogamulizumab treated patients, 3 patients demonstrated a response (ORR = 50%; 3/6). Five of 9 ATL patients continued on valemetostat treatment for more than 12 weeks with tumor shrinkage (Figure). Four ATL patients continue on treatment. The latest study results will be presented. Conclusion: The updated results of this ongoing phase I study showed that the oral EZH1/2 dual inhibitor valemetostat has demonstrated acceptable safety and promising preliminary efficacy in NHL. In addition, the results of ATL patients, including mogamulizumab pretreated patients, showed promising clinical activity. A subsequent pivotal phase II study for ATL will soon be initiated. Clinical trial information: NCT02732275 Disclosures Ishitsuka: Novartis: Honoraria, Research Funding; sanofi: Honoraria; Celgene: Honoraria; Astellas Pharma: Honoraria, Research Funding; Pfizer: Honoraria; Takeda Pharmaceutical: Honoraria, Research Funding; Janssen Pharmaceutical: Honoraria; Janssen Pharmaceutical: Honoraria; Shire: Honoraria; Eisai: Honoraria, Research Funding; Otsuka Pharmaceutical: Honoraria; Mochida: Honoraria, Research Funding; Shire: Honoraria; Teijin Pharma: Research Funding; Sumitomo Dainippon Pharma: Honoraria, Research Funding; Astellas Pharma: Honoraria, Research Funding; Sumitomo Dainippon Pharma: Honoraria, Research Funding; Novartis: Honoraria, Research Funding; Genzyme: Honoraria; Genzyme: Honoraria; Eisai: Honoraria, Research Funding; Ono Pharmaceutical: Honoraria, Research Funding; Teijin Pharma: Research Funding; MSD: Research Funding; Yakult: Research Funding; Asahi kasei: Research Funding; MSD: Research Funding; Asahi kasei: Research Funding; Eli Lilly: Research Funding; Eli Lilly: Research Funding; Daiichi Sankyo: Consultancy, Honoraria; Daiichi Sankyo: Consultancy, Honoraria; Kyowa Hakko Kirin: Honoraria, Research Funding; mundiharma: Honoraria; Taiho Pharmaceutical: Honoraria, Research Funding; Alexion: Honoraria; Mochida: Honoraria, Research Funding; Takeda Pharmaceutical: Honoraria, Research Funding; mundiharma: Honoraria; Taiho Pharmaceutical: Honoraria, Research Funding; Otsuka Pharmaceutical: Honoraria; Ono Pharmaceutical: Honoraria, Research Funding; Yakult: Research Funding; Bristol-Myers Squibb: Honoraria; Chugai Pharmaceutical: Honoraria, Research Funding; Pfizer: Honoraria; Alexion: Honoraria; sanofi: Honoraria. Izutsu:Eisai, Chugai, Zenyaku: Honoraria; Chugai, Celgene, Daiichi Sankyo, Astra Zeneca, Eisai, Symbio, Ono, Bayer, Solasia, Zenyaku, Incyte, Novartis, Sanofi, HUYA Bioscience, MSD, Astellas Amgen, Abbvie, ARIAD, Takeda, Pfizer: Research Funding; Celgene: Consultancy; Eisai, Symbio, Chugai, Zenyaku: Research Funding; Kyowa Kirin, Eisai, Takeda, MSD, Chugai, Nihon Medi-physics, Janssen, Ono, Abbvie, Dainihon Sumitomo, Bayer, Astra Zeneca, HUYA Japan, Novartis, Bristol-Byers Squibb, Mundi, Otsuka, Daiichi Sankyo, Astellas, Asahi Kasei: Honoraria. Kusumoto:Chugai Pharmaceutical Co., Ltd.: Consultancy, Honoraria, Research Funding; Kyowa Kirin Co., Ltd.: Honoraria, Research Funding. Araki:Daiichi Sankyo: Employment. Adachi:Daiichi Sankyo: Employment. Yamashita:Daiichi Sankyo: Employment. Atsumi:Daiichi Sankyo: Employment. Tsukasaki:Eisai: Research Funding; Mundi Pharma: Honoraria; Chugai Pharmaceutical: Honoraria, Research Funding; Huya: Consultancy, Honoraria, Research Funding; Byer: Research Funding; Kyowa Kirin: Honoraria; Ono Pharmaceutical: Consultancy; Celgene: Honoraria, Research Funding; Daiichi Sankyo: Consultancy. Tobinai:Eisai: Honoraria, Research Funding; Kyowa Kirin: Honoraria, Research Funding; Daiichi Sankyo: Consultancy, Honoraria; Takeda Pharmaceutical: Consultancy, Honoraria, Research Funding; Chugai Pharmaceutical: Honoraria, Research Funding; Celgene: Consultancy, Honoraria, Research Funding; Zenyaku Kogyo: Consultancy, Honoraria; Meiji Seika: Honoraria; Verastem: Honoraria; Solasia: Honoraria; Janssen Pharmaceutical: Honoraria, Research Funding; Yakult: Honoraria; AbbVie: Research Funding; Ono Pharmaceutical: Consultancy, Honoraria, Research Funding; Mundi Pharma: Consultancy, Honoraria, Research Funding; HUYA Bioscience: Consultancy, Honoraria; Bristol-Myers Squibb: Honoraria.

Introduction: In limited-stage diffuse large B-cell lymphoma (DLBCL), a continued risk of relapse has been reported (Stephens et al. J Clin Oncol 2016). Another report highlighted that initial limited-stage DLBCL, a favorable International Prognostic Index and extranodal involvement seemed to be risk factors for late relapse (LR; Larouche et al. J Clin Oncol 2010). However, even if a subgroup of patients (pts) with LR shows distinct clinical characteristics, the underlying biology is largely unknown. Methods: Nineteen consecutive pts who developed LR were identified among 337 pts with de novo DLBCL of Ann Arbor stage I/II who were treated with CHOP (cyclophosphamide, doxorubicin, vincristine and prednisolone), with/without rituximab, between 1997 and 2012. LR was defined as the first relapse of B-cell lymphoma (BCL; including indolent BCL) occurring more than 5 years after a primary diagnosis. The 19 pts underwent clinical, pathological (cell of origin according to the Hans algorithm) and genetic analyses. Genomic DNA (gDNA) was extracted from formalin-fixed, paraffin-embedded sections of tumor specimens at primary diagnosis and relapse, and from bone marrow (BM) specimens without tumor invasion as controls. Genomic DNA samples from paired primary and relapsed tumors were analyzed using BIOMED-2 multiplex PCR for immunoglobulin heavy chain (IGH) rearrangements (Invivoscribe Technologies, San Diego, CA, USA) to determine whether the paired tumors shared the same clonal IGH rearrangements. Target sequencing of 2709 regions across 69 lymphoma-related genes was performed on gDNA samples. Mutational calls were made in comparisons with individual control BM gDNA samples according to the criteria outlined in Table 1. All functional mutations detected in paired tumors per pt were compared, and shared and non-shared mutations were identified. Results: Baseline characteristics of the 19 pts were as follows: median age of 60 years (range, 32-77); 13 (68%) had stage I disease, and 11 (58%) had extranodal disease. At primary diagnosis, 14 of 19 pts (74%) had a non-germinal center B-cell-like (non-GCB) type DLBCL. As an initial treatment, CHOP therapy (median 4 cycles; range, 3-8), with (n=17) or without (n=2) radiation therapy, was performed in all 19 pts. Seven pts were treated with CHOP and rituximab. The median duration from initial diagnosis to LR was 8 years (range, 5-18). At LR, the median age was 71 years (range, 45-84). One pt relapsed as a composite of DLBCL and indolent BCL, and two pts relapsed as indolent BCL. Seven of the 19 pts were excluded from gene analysis because their paired gDNAs were of poor quality. The results of target sequencing combined with clinicopathological information and the results of IGH-PCR analysis are described in Table 2. Shared mutations between individual pairs of primary and relapsed tumors were detected in nine of the 12 pts analyzed. The most frequent shared mutation was a CD79B missense mutation of a single base substitution in positions 196 (n=5) or 199 (n=2). The second most frequent mutation was a MYD88 (L265P) missense mutation (n=5). Co-mutation of CD79B and MYD88 was found in four pts, who were considered to have a MCD (MyD88,CD79b) type DLBCL (Schmitz et al. N Engl J Med 2018). All eight pts with a CD79B and/or MYD88 mutation had a non-GCB type DLBCL. The same clonal IGH rearrangements between paired tumors were found in six of the eight pts. Seven of the eight pts presented with primarily extranodal disease originating from the testis (n=3), nasal/paranasal cavity (n=2) or gingiva (n=2). One pt (#9 in Table 2) with a GCB type DLBCL had shared mutations in MLL2, CREBBP, MEF2B and PIM1. However, different clonal IGH rearrangements were detected between paired tumors, implying these mutations may be the basis for lymphomagenesis; an on-going IGH rearrangement may occur. In the other three pts (#10-12), shared mutations were not detected. Mutations in TP53 were not detected in any pts. We did not identify any specific mutations considered to be associated with LR. Conclusions: Common characteristics shared in a subgroup of pts with limited-stage DLBCL who developed LR were as follows: non-GCB type, CD79B and/or MYD88 mutations, and extranodal disease at primary manifestation. The mechanisms of LR from the viewpoint of gene alterations were considered heterogeneous. Disclosures Maruyama: Asahi Kasei Pharma: Honoraria; Takeda: Honoraria, Research Funding; Bristol-Myers Squibb: Honoraria; Dai-ichi-Sankyo: Honoraria; Dai-Nippon-Sumitomo: Honoraria; MSD: Honoraria, Research Funding; Chugai Pharma: Honoraria, Research Funding; Eisai: Honoraria, Research Funding; Fujifilm: Honoraria, Research Funding; Zenyaku Kogyo: Honoraria, Research Funding; AstraZeneca: Research Funding; Ono Pharmaceutical: Honoraria, Research Funding; Kyowa Hakko Kirin: Honoraria, Research Funding; GlaxoSmithKline: Research Funding; Abbvie: Research Funding; Astellas Pharma: Research Funding; Amgen Astellas BioPharma: Research Funding; Otsuka: Research Funding; Novartis: Research Funding; Nippon Boehringer Ingelheim: Research Funding; Pfizer: Research Funding; Solasia Pharma: Research Funding; Celgene: Honoraria, Research Funding; Biomedis International: Honoraria, Research Funding; Mundipharma International: Honoraria, Research Funding; Janssen: Honoraria, Research Funding. Izutsu:Amgen: Research Funding; Daiichi Sankyo: Honoraria, Research Funding; Kyowa Hakko Kirin: Honoraria; Bayer: Consultancy, Honoraria, Research Funding; Takeda: Honoraria, Research Funding; Abbvie: Honoraria, Research Funding; MSD: Honoraria; HUYA Bioscience International: Research Funding; Celgene: Consultancy, Research Funding; Celltrion: Research Funding; Zenyaku: Research Funding; Sanofi: Research Funding; Gilead Sciences: Honoraria; Eisai: Honoraria, Research Funding; Novartis: Honoraria; Ono: Honoraria, Research Funding; Chugai: Honoraria, Research Funding; Nihon Medi-Physics: Honoraria; Symbio: Research Funding; Solasia: Research Funding; Mundhi: Honoraria; Otsuka: Honoraria; Bristol- Myers Squibb: Honoraria; Janssen: Honoraria, Research Funding; Astellas: Honoraria, Research Funding; Meiji Seika: Honoraria; Shionogi: Honoraria; Asahi Kasei: Honoraria. Tobinai:Takeda: Honoraria, Research Funding; SERVIER: Research Funding; Abbvie: Research Funding; Ono Pharmaceutical: Honoraria, Research Funding; Mundipharma: Honoraria, Research Funding; HUYA Bioscience International: Consultancy, Honoraria; Zenyaku Kogyo: Consultancy, Honoraria; Celgene: Consultancy, Honoraria, Research Funding; GlaxoSmithKline: Research Funding; Chugai Pharma: Honoraria, Research Funding; Kyowa Hakko Kirin: Honoraria, Research Funding; Janssen: Honoraria, Research Funding; Eisai: Honoraria, Research Funding. Kobayashi:Pfizer: Research Funding; Ohtuka: Research Funding; Astellas: Research Funding.

BACKGROUND JULIET (NCT02445248) is a single-arm, open-label, multicenter, global, pivotal phase 2 trial of tisagenlecleucel, a chimeric antigen receptor (CAR)-T cell therapy targeting CD19, that has shown a high rate of durable complete responses (CR) and a manageable safety profile in adult patients with clinically active relapsed/refractory (r/r) diffuse large B-cell lymphoma (DLBCL). The primary objective was met at the interim analysis, with an overall response rate (ORR) of 59% (CR, 43%; partial response [PR], 16%). Here, we present an updated analysis of the JULIET trial, with a median of 19 months of follow-up, an additional 5 months since the previous report (Schuster et al. EHA 2018), demonstrating sustained activity in this patient population. METHODS Eligible patients were ≥18 years with r/r DLBCL, had received ≥2 lines of therapy, including rituximab and an anthracycline, and were ineligible for or had failed autologous stem cell transplant (ASCT). Tisagenlecleucel was centrally manufactured at 2 facilities (Morris Plains, NJ, USA [main cohort] and Leipzig, Germany [cohort A]) using cryopreserved apheresis material and provided to patients at 27 treatment sites across 10 countries on 4 continents using a global supply chain. The primary endpoint was ORR (CR + PR) per independent review committee. Efficacy results are reported for patients in the main cohort with ≥3 months of follow-up or earlier discontinuation; safety is reported for all infused patients. RESULTS At data cutoff (May 21, 2018), 167 patients were enrolled and 115 were infused (99 in the main cohort and 16 in cohort A) with a single dose of tisagenlecleucel (median, 3.0×108 [range, 0.1-6.0×108] CAR-positive viable T cells). 90% of infused patients received bridging therapy and 93% received lymphodepleting chemotherapy. Median time from infusion to data cutoff was 19.3 months. Median age was 56 years (range, 22-76 years); 23% were aged ≥65 years. At study entry, 77% of infused patients had stage III/IV disease and 17% had double/triple hit disease. 55% and 43% had germinal center and activated B-cell molecular subtypes, respectively. 51% of patients had received ≥3 prior lines of antineoplastic therapy (range, 1-6); 49% had undergone a prior ASCT. All 99 patients in the main cohort had ≥3 months of follow-up or discontinued earlier and were evaluable for efficacy. ORR was 54% (95% CI, 43%-64%), with 40% CR and 13% PR. ORR was consistent across prognostic subgroups (including prior ASCT and double/triple-hit lymphoma). Median duration of response (DOR) was not reached; the probability of being relapse free was 66% (95% CI, 51%-78%) at 6 months and 64% (95% CI, 48%-76%) at 12 and 18 months. DOR was similar by age group (≥ vs < 65 years) and by relapsed or refractory status (Figure). No relapses were observed beyond 11 months after infusion. Median OS for all infused patients was 11.1 months (95% CI, 6.6 months-NE) and not reached (95% CI, 21 months-NE) for patients in CR. OS probability was 48% (95% CI, 38%-57%) at 12 months and 43% (95%CI, 33%-53%) at 18 months (max follow-up, 29 months). No patients proceeded to allogeneic SCT or ASCT while in remission. Grade 3 or 4 adverse events (AEs) of special interest within 8 weeks of infusion included cytopenias lasting >28 days (34%), cytokine release syndrome (CRS; 23%, by the Penn scale), infections (19%), febrile neutropenia (15%), neurological events (11%; 1 case of grade 2 cerebral edema), and tumor lysis syndrome (2%). 16% of patients received tocilizumab for CRS management. 3 patients died within 30 days of infusion (all due to disease progression). No treatment-related mortality was reported. Since the previous report, no new deaths occurred due to causes other than disease progression. CONCLUSION Results from this longer-term follow-up show that tisagenlecleucel produced high response rates and durable responses in a cohort of heavily pretreated adult patients with r/r DLBCL. Efficacy was consistent in all predefined subgroups, including elderly patients, patients with r/r disease, and other clinical or biological subgroups expected to have a worse prognosis with available treatments, as demonstrated by similar and sustained DOR and OS following tisagenlecleucel treatment. Figure. Figure. Disclosures Schuster: Genentech: Honoraria, Research Funding; Merck: Consultancy, Honoraria, Research Funding; Gilead: Membership on an entity's Board of Directors or advisory committees; Nordic Nanovector: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis Pharmaceuticals Corporation: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Dava Oncology: Consultancy, Honoraria. Bishop:Juneau Therapeutics: Speakers Bureau; Celgene: Honoraria, Speakers Bureau; Seattle Genetics: Consultancy, Membership on an entity's Board of Directors or advisory committees; United Healthcare: Employment; Novartis Pharmaceuticals Corporation: Speakers Bureau. Tam:AbbVie: Honoraria, Research Funding; Janssen: Honoraria, Research Funding; Beigene: Honoraria. Borchmann:Novartis: Consultancy, Honoraria. Jaeger:Roche: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Takeda-Millenium: Membership on an entity's Board of Directors or advisory committees; Infinity: Membership on an entity's Board of Directors or advisory committees; Mundipharma: Membership on an entity's Board of Directors or advisory committees; Takeda-Millenium: Membership on an entity's Board of Directors or advisory committees; Amgen: Membership on an entity's Board of Directors or advisory committees; MSD: Research Funding; Gilead: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Bioverativ: Membership on an entity's Board of Directors or advisory committees; Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; GSK: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees, Research Funding; AbbVie: Consultancy, Honoraria; AOP Orphan: Membership on an entity's Board of Directors or advisory committees. Waller:Pharmacyclics: Other: Travel Expenses, EHA, Research Funding; Celldex: Research Funding; Kalytera: Consultancy; Novartis Pharmaceuticals Corporation: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Cambium Medical Technologies: Consultancy, Equity Ownership. Holte:Novartis Pharmaceuticals Corporation: Membership on an entity's Board of Directors or advisory committees; Roche, Norway: Research Funding. McGuirk:Novartis Pharmaceuticals Corporation: Honoraria, Other: speaker, Research Funding; Kite Pharma: Honoraria, Other: travel accommodations, expenses, speaker ; Fresenius Biotech: Research Funding; Pluristem Ltd: Research Funding; Gamida Cell: Research Funding; Bellicum Pharmaceuticals: Research Funding; Astellas Pharma: Research Funding. Jaglowski:Kite Pharma: Consultancy, Research Funding; Novartis Pharmaceuticals Corporation: Consultancy, Research Funding; Juno: Consultancy. Tobinai:Abbvie: Research Funding; SERVIER: Research Funding; Takeda: Honoraria, Research Funding; Mundipharma: Honoraria, Research Funding; Eisai: Honoraria, Research Funding; GlaxoSmithKline: Research Funding; Janssen: Honoraria, Research Funding; Ono Pharmaceutical: Honoraria, Research Funding; Kyowa Hakko Kirin: Honoraria, Research Funding; Chugai Pharma: Honoraria, Research Funding; HUYA Bioscience International: Consultancy, Honoraria; Zenyaku Kogyo: Consultancy, Honoraria; Celgene: Consultancy, Honoraria, Research Funding. Andreadis:Cellerant Therapeutics: Research Funding; Novartis Pharmaceuticals Corporation: Honoraria, Research Funding; Incyte Pharmaceuticals: Research Funding; Pharmacyclics: Research Funding; Amgen: Research Funding; Genentech Inc.: Honoraria, Research Funding; Seattle Genetics: Honoraria; Gilead Sciences: Honoraria; Astellas: Honoraria. Fleury:F. Hoffmann-La Roche Ltd: Consultancy; Lundbeck: Consultancy; Gilead: Consultancy; Seattle Genetics: Consultancy; Janssen: Consultancy; Merck: Consultancy; Novartis Pharmaceuticals Corporation: Consultancy; Celgene: Consultancy. Mielke:Celgene: Speakers Bureau; KIADIS Pharma: Speakers Bureau; Miltenyi Biotec: Speakers Bureau; DGHO: Speakers Bureau; EHA: Speakers Bureau. Westin:Apotex: Membership on an entity's Board of Directors or advisory committees; Kite Pharma: Membership on an entity's Board of Directors or advisory committees; Celgen: Membership on an entity's Board of Directors or advisory committees; Novartis Pharmaceuticals Corporation: Membership on an entity's Board of Directors or advisory committees. Bachanova:Kite Pharma: Membership on an entity's Board of Directors or advisory committees; Gamida Cell: Research Funding; GT Biopharma: Research Funding. Foley:Celgene: Honoraria, Speakers Bureau; Novartis Pharmaceuticals Corporation: Consultancy, Honoraria, Other: Travel expenses ; Amgen: Honoraria; Janssen: Speakers Bureau; Jazz Pharma: Other: Travel expenses . Ho:Amgen: Honoraria; Janssen: Honoraria; Novartis: Honoraria; Takeda: Honoraria, Other: travel to meeting; Celgene: Other: travel to meeting. Wagner-Johnston:JUNO: Honoraria, Membership on an entity's Board of Directors or advisory committees; Merck: Research Funding; ADC Therapeutics: Honoraria, Membership on an entity's Board of Directors or advisory committees; ASTEX: Research Funding; Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Novartis: Research Funding; Celgene: Research Funding. Kersten:Millennium/Takeda: Honoraria, Research Funding; Celgene: Honoraria, Research Funding; Roche: Honoraria, Research Funding; Kite/Gilead: Honoraria; Novartis Pharmaceuticals Corporation: Honoraria. Chu:Novartis Pharmaceuticals Corporation: Employment. Jary:Novartis Pharma AG: Employment. Anak:Novartis Pharma AG: Employment. Salles:Celgene: Honoraria, Other: Advisory Board, Research Funding; F. Hoffmann-La Roche Ltd: Consultancy, Honoraria, Research Funding; Pfizer: Honoraria; Takeda: Honoraria; Amgen: Honoraria; Servier: Honoraria, Other: Advisory Board; Merck: Honoraria; Janssen: Honoraria, Other: Advisory Board; Gilead: Honoraria, Other: Advisory Board; Novartis: Consultancy, Honoraria; Acerta: Honoraria; Morphosys: Honoraria; Servier: Honoraria; BMS: Honoraria, Other: Advisory Board; Epizyme: Honoraria; Abbvie: Honoraria. Maziarz:Novartis Pharmaceuticals Corporation: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Incyte: Consultancy, Honoraria; Juno Therapeutics: Consultancy, Honoraria; Kite Therapeutics: Honoraria; Athersys, Inc.: Patents & Royalties.

Enhancer of zests homologous (EZH)1 and its close homolog EZH2 are component of polycomb repressive complex (PRC) 2 protein complex, and play redundant and crucial role for the maintenance of transcriptional repression by tri-methylating histone H3 lysine 27 (H3K27). Hyper tri-methylation of H3K27 has been associated with lymphoma and myeloma progression, suggesting that PRC2 is a therapeutic target for hematological malignancies. Selective EZH2 inhibitors induce compensatory activation of EZH1 which in turn re-activates PRC2 function. We hypothesized that dual inhibition of EZH1 and EZH2 is more effective than selective EZH2 inhibition as anti-tumor therapy. We have developed a novel EZH1 and EZH2 dual inhibitor DS-3201, which simultaneously inhibited the enzymatic activity of EZH1 and EZH2 in nano-molar concentration. DS-3201 showed anti-proliferative effect against various NHL cells, such as diffuse large B-cell lymphoma (DLBCL), mantle cell lymphoma, and peripheral T-cell lymphoma, with GI50 values less than 100 nM regardless of EZH2 gain-of-function mutations. DS-3201 also induced differentiation of undifferentiated NHL cells with increment of cell lineage specific markers and which induced cell death in vitro. DS-3201 also showed synergistic effect with the standard of care agents for NHL in vitro and in vivo. An open-label phase 1 clinical study was initiated to examine the safety and pharmacokinetics of multiple-dose monotherapy of DS-3201b which is the salt form of DS-3201 in patients with NHL (ClinicalTrials.gov Identifier: NCT02732275). Eighteen patients with relapsed or refractory NHL were enrolled. The patients received oral administration of DS-3201b once daily in a 28-day cycle at dose of 150, 200 and 300 mg. Preliminary efficacy results (D. Maruyama, et al. ASH 2017), showed that the overall response rate was 58.8% (10/17) with 1 complete response and 9 partial responses (PR). Thirteen NHL patients including five follicular lymphoma (FL) and one DLBCL were analyzed for gene mutation status by targeted gene sequencing. EZH2 mutation was detected only in one FL patient, who achieved PR. It was suggested that DS-3201b has clinical activity against NHL, regardless of the mutation status of EZH2. Disclosures Honma: Daiichi Sankyo: Employment. Nosaka:Daiichi Sankyo: Employment. Shiroishi:Daiichi Sankyo: Employment. Takata:Daiichi Sankyo: Employment. Hama:Daiichi Sankyo: Employment. Yamamoto:Daiichi Sankyo RD Novare: Employment. Adachi:Daiichi Sankyo: Employment. Maruyama:Mundipharma International: Honoraria, Research Funding; MSD: Honoraria, Research Funding; Chugai Pharma: Honoraria, Research Funding; Dai-ichi-Sankyo: Honoraria; Bristol-Myers Squibb: Honoraria; Biomedis International: Honoraria, Research Funding; Celgene: Honoraria, Research Funding; Kyowa Hakko Kirin: Honoraria, Research Funding; Fujifilm: Honoraria, Research Funding; Ono Pharmaceutical: Honoraria, Research Funding; Takeda: Honoraria, Research Funding; Janssen: Honoraria, Research Funding; Eisai: Honoraria, Research Funding; Dai-Nippon-Sumitomo: Honoraria; Asahi Kasei Pharma: Honoraria; AstraZeneca: Research Funding; Solasia Pharma: Research Funding; Pfizer: Research Funding; Nippon Boehringer Ingelheim: Research Funding; Novartis: Research Funding; Otsuka: Research Funding; Amgen Astellas BioPharma: Research Funding; Astellas Pharma: Research Funding; Abbvie: Research Funding; GlaxoSmithKline: Research Funding; Zenyaku Kogyo: Honoraria, Research Funding. Tobinai:Chugai Pharma: Honoraria, Research Funding; Kyowa Hakko Kirin: Honoraria, Research Funding; Ono Pharmaceutical: Honoraria, Research Funding; Janssen: Honoraria, Research Funding; GlaxoSmithKline: Research Funding; Eisai: Honoraria, Research Funding; Mundipharma: Honoraria, Research Funding; Takeda: Honoraria, Research Funding; SERVIER: Research Funding; Abbvie: Research Funding; Celgene: Consultancy, Honoraria, Research Funding; Zenyaku Kogyo: Consultancy, Honoraria; HUYA Bioscience International: Consultancy, Honoraria. Ishida:Kyowa Hakko Kirin Co.Ltd: Honoraria, Research Funding; Celgene K.K: Honoraria, Research Funding; Bayer AG: Research Funding; Mundiparma K: Honoraria. Kusumoto:Bristol-Myers Squibb: Honoraria, Research Funding; Chugai Pharmaceutical Co. Ltd: Honoraria, Research Funding; Kyowa Hakko Kirin: Honoraria, Research Funding. Tsukasaki:Daiich-Sankyo: Consultancy; Ono Pharma: Consultancy; HUYA: Consultancy, Research Funding; Chugai Pharma: Honoraria, Research Funding; Eisai: Research Funding; Celgene: Honoraria; Mundy Pharma: Honoraria; Kyowa-hakko/Kirin: Honoraria; Seattle Genetics: Research Funding. Fujioka:Daiichi Sankyo: Employment. Watanabe:Daiichi Sankyo: Employment. Kanno:Daiichi Sankyo: Employment. Kumazawa:Daiichi Sankyo RD Novare: Employment. Fujitani:Daiichi Sankyo: Employment. Araki:Daiichi Sankyo: Employment. Fujiwara:Daiichi Sankyo: Employment.

Background: CHOP plus rituximab (R-CHOP) is the standard of care for previously untreated DLBCL. R-CHOP comprises CHOP and one-dose rituximab in each 21-day cycle; however, the schedule of rituximab administration has not been fully optimized. Dose-dense rituximab was expected to increase its peak concentration to enhance the synergistic effect with chemotherapy at early phase of treatment. To compare weekly administration of rituximab combined with CHOP (RW-CHOP) with standard R-CHOP in patients with previously untreated DLBCL, we conducted a multicenter, randomized phase II/III study (JCOG0601, UMIN000000929). Methods: Previously untreated patients with CD20+ DLBCL were eligible. Other major inclusion criteria were as follows: aged 20-79 years; ECOG performance status 0-2, at least 1 measurable lesion and preserved organ functions. At the beginning of the study, patients with advanced stage disease and the low or low-intermediate risk group by the International Prognostic Index (IPI) were eligible. These criteria were amended in September 2010 to allow enrollment of the patients with any IPI risk and any clinical stage because of slow accrual. Patients were randomly assigned to standard R-CHOP (rituximab 375 mg/m2, cyclophosphamide 750 mg/m2, doxorubicin 50 mg/m2, vincristine 1.4 mg/m2 [max 2 mg], all IV on day 1, and prednisone 100 mg/day PO [40mg/m2 for aged >65] on days 1-5, every 3 weeks) or RW-CHOP (standard CHOP with eight doses of weekly rituximab [375mg/m2 IV on days1, 8, 15, 22, 29, 36, 43 and 50]). Six cycles of CHOP were given in stage I non-bulky patients, 8 cycles were given in stage I bulky and II-IV patients, and rituximab was given 8 times regardless of cycles of CHOP. Randomization was stratified by institution, presence or absence of bulky mass and patient age. The primary endpoint of phase III part was progression-free survival (PFS). Secondary endpoints included overall survival (OS) and adverse events (AE). Assuming 3-year PFS in the R-CHOP arm to be 77% and expecting a 7% increase in 3-year PFS of the RW-CHOP arm, required sample size was 211 per arm with a one-sided alpha of 5%, power of 80%, an accrual period of 7 years, and a follow-up period of 3 years. Results: Between December 2007 and December 2014, a total of 422 patients were randomized to study treatments but primary analysis was performed in 421 patients: 213 to the R-CHOP arm and 208 to the RW-CHOP arm, because of one consent withdrawal. Baseline characteristics of 421 eligible patients were as follows (R-CHOP vs. RW-CHOP): median age, 61 vs. 62 years; male sex, 54.5% vs. 55.8%; Ann Arbor stage I/II/III/IV, 14.6/32.9/26.8/25.8% vs. 16.3/42.8/20.2/20.7%; and IPI score ≤2, 77.0% vs. 87.5%. With a median follow-up of 63.4 months (range: 3.2-119.2) among all patients, there was no significant difference in PFS between the arms (hazard ratio [HR], 0.95; 90.6% confidence interval [CI], 0.68 to 1.31; one-sided log-rank P = 0.39). The 3-year PFS and OS were 79.2% and 88.7% with the R-CHOP arm and 80.3% and 90.4% with the RW-CHOP arm, respectively. The complete response rate and overall response rate were 77.0% and 93.0% in the R-CHOP arm and 82.2% and 91.8% in the RW-CHOP arm, respectively. Major AEs were hematological toxicities and infections. Grade (G) 3/4 neutropenia and G 3/4 thrombocytopenia were observed in 97.7% and 8.0% in the R-CHOP arm and 97.1% and 5.3% in the RW-CHOP arm, respectively. G3 febrile neutropenia was occurred in 33.8% in the R-CHOP arm and in 22.1% in the RW-CHOP arm. The frequency of severe AE was 2.3% in the R-CHOP arm and 3.8% in the RW-CHOP arm. Safety profile was comparable. No unexpected AEs were experienced. Conclusion: In combination of standard CHOP and rituximab, dose-dense weekly rituximab at early phase of treatment did not improve the PFS in patients with untreated DLBCL. Figure. Figure. Disclosures Ohmachi: Celgene: Honoraria; Takeda Pharmaceutical Co., Ltd,: Honoraria; Pfizer: Honoraria; Chugai Pharma: Honoraria; Kyowa Hakko Kirin: Honoraria; Eisai: Honoraria; Janssen: Honoraria; Meiji Pharma: Honoraria. Kinoshita:Takeda: Honoraria; Takeda: Research Funding; Ono: Research Funding; MSD: Research Funding; Solasia: Research Funding; Janssen: Honoraria; Ono: Honoraria; Zenyaku: Research Funding; Eisai: Research Funding; Gilead: Research Funding. Tobinai:Kyowa Hakko Kirin: Honoraria, Research Funding; Zenyaku Kogyo: Consultancy, Honoraria; Celgene: Consultancy, Honoraria, Research Funding; Janssen: Honoraria, Research Funding; GlaxoSmithKline: Research Funding; Ono Pharmaceutical: Honoraria, Research Funding; Eisai: Honoraria, Research Funding; Mundipharma: Honoraria, Research Funding; Takeda: Honoraria, Research Funding; Chugai Pharma: Honoraria, Research Funding; HUYA Bioscience International: Consultancy, Honoraria; SERVIER: Research Funding; Abbvie: Research Funding. Fukuhara:Sumitomo Dainippon: Research Funding; Solasia: Research Funding; Symbio: Research Funding; Sanofi: Research Funding; Pfizer: Research Funding; Otsuka Pharmaceutical: Research Funding; Ono: Honoraria, Research Funding; Novartis pharma: Research Funding; Nippon-shinyaku: Research Funding; MSD: Research Funding; Mundipharma: Honoraria, Research Funding; Mitsubishi Tanabe: Research Funding; Kyowa Hakko Kirin: Honoraria, Research Funding; Japan Blood Products Organization: Research Funding; Janssen: Honoraria, Research Funding; GlaxoSmithKline: Research Funding; Eisai: Honoraria, Research Funding; Boehringer Ingelheim: Research Funding; Daiichi-Sankyo: Research Funding; Chugai: Research Funding; Celgene: Research Funding; Baxalta: Research Funding; Bristol-Myers Squibb: Honoraria, Research Funding; Bayer Yakuhin: Research Funding; Alexionpharma: Research Funding; AbbVie: Research Funding; Astellas: Research Funding; Nihon Ultmarc: Research Funding; Taiho: Research Funding; Teijin Pharma: Research Funding; Zenyaku Kogyo: Honoraria, Research Funding; Takeda: Honoraria. Uchida:Takeda Pharmaceutical: Honoraria; Chugai Pharmaceutical: Honoraria; Kyowa Hakko Kirin: Honoraria; Meiji Seika Pharma: Honoraria; Bristol-Myers Squibb: Honoraria; Pfizer: Honoraria; Nippon Shinyaku: Honoraria; Novartis: Honoraria; Teijin: Honoraria; Celgene: Honoraria; Mundipharma: Honoraria; Janssen Pharma: Honoraria; Otsuka Pharmaceutical: Honoraria; Eisai: Honoraria. Yamamoto:Solasia Pharma: Research Funding; Bristol-Myers Squibb: Honoraria; Novartis: Honoraria, Research Funding; ARIAD Pharmaceuticals: Research Funding; Bayer: Research Funding; Celgene: Honoraria, Research Funding; Eisai: Honoraria, Research Funding; Ono: Consultancy, Honoraria, Research Funding; AbbVie: Research Funding; Boehringer Ingelheim: Consultancy; Chugai: Consultancy, Honoraria, Research Funding; Meiji Seika Pharma: Consultancy; MSD: Research Funding; Takeda: Honoraria, Research Funding; Zenyaku: Research Funding; Kyowa Hakko Kirin: Honoraria; Otsuka: Honoraria; Pfizer: Honoraria; Sumitomo Dainippon: Honoraria; Mundipharma: Consultancy, Honoraria; HUYA: Honoraria; SymBio: Research Funding; Gilead Sciences: Research Funding. Miyazaki:Kyowa Hakko Kirin,: Honoraria, Research Funding; Celgene: Honoraria; Chugai Pharma,: Honoraria, Research Funding; Sumitomo Group: Research Funding; Nippon Shinyaku: Research Funding; Takeda: Research Funding; Astellas Pharma: Research Funding; Shionogi Pharmaceutical: Research Funding; Daiichi Sankyo: Research Funding; Eisai: Research Funding; Novartis: Research Funding; Pfizer: Research Funding; Teijin Pharma: Research Funding; Ono Pharmaceutical: Research Funding; Toyama Chemical Co: Research Funding; Mochida Pharmaceutical Co. Ltd.: Research Funding; Novo Nordisk: Research Funding. Tsukamoto:Kyowa-Kirin: Research Funding; Pfizer: Research Funding; Chugai: Research Funding; Eisai: Research Funding. Iida:Teijin Pharma: Research Funding; Toyama Chemical: Research Funding; Ono: Consultancy, Honoraria, Research Funding; Kyowa-Hakko Kirin: Research Funding; Chugai: Research Funding; Celgene: Honoraria, Research Funding; Novartis: Honoraria, Research Funding; Astellas: Research Funding; Takeda: Consultancy, Honoraria, Research Funding; Gilead: Research Funding; MSD: Research Funding; Janssen: Consultancy, Honoraria, Research Funding; Bristol Myers Squibb: Honoraria, Research Funding; Sanofi: Consultancy. Yoshida:Taiho Pharma: Honoraria; Takeda Pharma: Honoraria; Celegene: Honoraria; Chugai Pharma: Honoraria, Research Funding; Kyowa Hakko Kirin: Honoraria, Research Funding. Masaki:Ono: Research Funding; Kyowa Hakko Kirin: Research Funding; Phizer: Research Funding; Astellas: Research Funding; Eisai: Research Funding. Yakushijin:Mundipharma Co.,: Research Funding; Chugai Co.,: Research Funding; Kyowa-kirin Co.,: Research Funding; Merch Sharp & Dohme Corp.,,: Research Funding; Daiichi-Sankyo Inc.,: Research Funding; Eisai Co.: Research Funding. Suehiro:Kyowa Hakko Kirin: Research Funding; Ono Pharmaceutical: Research Funding; Chugai Pharmaceutical: Research Funding; Takeda Pharmaceutical: Research Funding. Nosaka:Bristol-Myers Squibb: Honoraria; Ono Pharmaceutical Co.LTD.: Honoraria; Eisai Co. Ltd.,: Honoraria; Kyowa Kirin Pharmaceutical Development, Inc.,: Honoraria; Chugai Pharmaceutical Co.LTD.,: Honoraria; Celgene Co. LTD.,: Honoraria. Dobashi:Celgene Co.: Research Funding; Otsuka Pharmaceutical Co., Ltd.: Research Funding; Eisai Co., Ltd.: Research Funding; Zenyaku Kogyo Co., Ltd.: Research Funding; Kyowa Hakko Kirin Co. Ltd.: Research Funding; Astellas Pharma Inc.: Research Funding; Chugai Pharmaceutical Co., Ltd.: Research Funding; Pfizer Inc.: Research Funding; Sysmex Co.: Research Funding. Kuroda:Chugai Pharma: Honoraria, Research Funding. Takamatsu:Taisho Toyama Pharmaceutical: Research Funding; TAIHO Pharmaceutical: Research Funding; Pfizer: Research Funding; Bristol-Myers Squibb: Research Funding; Ono Pharmaceutical: Research Funding; Astellas Pharma: Research Funding; Kyowa Hakko Kirin: Research Funding; Chugai Pharma: Research Funding; Takeda Pharmaceutical: Research Funding; Celgene: Honoraria. Maruyama:Ono Pharmaceutical: Honoraria, Research Funding; Fujifilm: Honoraria, Research Funding; Kyowa Hakko Kirin: Honoraria, Research Funding; Asahi Kasei Pharma: Honoraria; AstraZeneca: Research Funding; Solasia Pharma: Research Funding; Pfizer: Research Funding; Nippon Boehringer Ingelheim: Research Funding; Dai-Nippon-Sumitomo: Honoraria; Dai-ichi-Sankyo: Honoraria; Bristol-Myers Squibb: Honoraria; Takeda: Honoraria, Research Funding; Janssen: Honoraria, Research Funding; Eisai: Honoraria, Research Funding; Biomedis International: Honoraria, Research Funding; Celgene: Honoraria, Research Funding; Chugai Pharma: Honoraria, Research Funding; MSD: Honoraria, Research Funding; Novartis: Research Funding; Otsuka: Research Funding; Amgen Astellas BioPharma: Research Funding; Zenyaku Kogyo: Honoraria, Research Funding; GlaxoSmithKline: Research Funding; Abbvie: Research Funding; Astellas Pharma: Research Funding; Mundipharma International: Honoraria, Research Funding. Ando:Eisai: Research Funding; Meiji Seika Pharma: Research Funding; Takeda Pharmaceutical: Research Funding; Kyowa Hakko Kirin: Research Funding; Japan Blood Products Organization: Research Funding. Ishizawa:Eisai: Honoraria; Janssen: Honoraria; Chugai: Honoraria; Celgene: Honoraria; Otsuka: Research Funding; Sanofi: Research Funding; Phizer: Research Funding. Ogura:Celltrion: Consultancy, Research Funding; Mundi Pharma: Consultancy; SymBio: Research Funding; Takeda: Honoraria; Cellgene: Honoraria; MeijiSeika Pharma: Consultancy. Hotta:SymBio: Consultancy; CellSeed Inc.: Membership on an entity's Board of Directors or advisory committees. Tsukasaki:Celgene: Honoraria; Eisai: Research Funding; Chugai Pharma: Honoraria, Research Funding; HUYA: Consultancy, Research Funding; Ono Pharma: Consultancy; Daiich-Sankyo: Consultancy; Mundy Pharma: Honoraria; Kyowa-hakko/Kirin: Honoraria; Seattle Genetics: Research Funding. Nagai:HUYA Bioscience International: Research Funding; Chugai Pharmaceutical Co., Ltd.: Honoraria, Research Funding; Ono Pharmaceutical Co., Ltd.: Honoraria, Research Funding; Celgene Corporation: Honoraria, Research Funding; Gilead Sciences Inc.: Honoraria, Research Funding; Bayer Yakuhin Ltd.: Research Funding; Sanofi K. K.: Honoraria; Zenyaku Kogyo Co., Ltd.: Honoraria, Research Funding; Solasia Pharma K.K.: Research Funding; Otsuka Pharmaceutical Co., Ltd.: Research Funding; Roche Ltd.: Honoraria; Esai Co., Ltd.: Honoraria, Research Funding; Takeda Pharmaceutical Co., Ltd.: Honoraria, Research Funding; Bristol-Myers Squibb: Honoraria, Research Funding; SymBio Pharmaceuticals Limited: Research Funding; Janssen Pharmaceutical K.K.: Honoraria, Research Funding; Kyowa Hakko Kirin Co., Ltd.: Honoraria, Research Funding; Mundipharma K.K.: Honoraria, Research Funding; AstraZeneca plc.: Research Funding; Abbvie G. K.: Research Funding.

Introduction: Peripheral T-cell lymphoma (PTCL) is an aggressive lymphoma associated with poor prognosis. There is no consensus on standard therapy, and options are limited for patients with relapsed/refractory (R/R) disease. Romidepsin, a potent histone deacetylase inhibitor, has US FDA approval for patients with >=1 prior treatment for PTCL based on 25%-38% overall response rates (ORR) and durable responses (Piekarz et al, Blood. 2011;117:5827; Coiffier et al, J Clin Oncol. 2012;30:631). Here we report results from the phase I/II, multicenter, open-label study of romidepsin in Japanese patients with R/R PTCL or cutaneous T-cell lymphoma (CTCL) (TCL-001; NCT01456039). Methods: Patients aged >=20 years with R/R PTCL or CTCL received romidepsin via a 4-hour IV infusion on days 1, 8, and 15 of each 28-day cycle until progressive disease or unacceptable toxicity. The phase I portion of the study used a 3+3 design to identify any dose-limiting toxicity (DLT; phase I primary endpoint) with romidepsin 9 mg/m2 (cohort 1) and 14 mg/m2 (cohort 2). The phase II dose was based on the highest dose where =1 day. Assessments of the intent-to-treat (ITT) population included all patients receiving at least 1 dose of romidepsin. Results: The ITT population comprised 48 patients with PTCL and 2 with CTCL (1 each in the 9 and 14 mg/m2 cohorts). The common PTCL subtypes were angioimmunoblastic T-cell lymphoma (AITL, n=21, 44%), PTCL not otherwise specified (PTCL-NOS, n=20, 42%), and anaplastic large-cell lymphoma (ALCL ALK-1 negative, n=3, 6%). Most patients had a favorable ECOG performance status (86% 0-1) and 72% were >=65 years of age. Patients had received a median of 2 prior therapies (range, 1-9). Of 9 patients assessable in phase I (n=3 at 9 mg/m2 and n=6 at 14 mg/m2), none experienced a DLT. The recommended phase II dose was 14 mg/m2 in 40 subsequently treated patients. The overall population received a median of 10 doses (range, 1-135) for a median treatment duration of 12.9 weeks (range, 0.1-184.3; 8 patients were treated for >=36 weeks). The common all-grade adverse events (AEs) were thrombocytopenia (n=49, 98%), lymphopenia (n=44, 88%), leukopenia (n=42, 84%), neutropenia (n=40, 80%), pyrexia (n=33, 66%), dysgeusia (n=31, 62%), decreased appetite (n=28, 56%), and nausea (n=27, 54%). The common grade >=3 AEs were lymphopenia (n=37, 74%), neutropenia (n=27, 54%), leukopenia (n=23, 46%), and thrombocytopenia (n=19, 38%). Of the 39 patients whose CD4+ T-cell counts were monitored, while decreased CD4+ T-cell counts ( Among the 40 patients with PTCL (phase II), the ORR was 43% (95% CI, 27%-58%), including 10 patients (25%) with complete response (CR) or CR unconfirmed (CRu) and 7 (17%) with partial responses (PR) (Table 1). The obtained ORR was significantly higher compared with the threshold ORR of 10% (P Conclusions: Results from this phase I/II study identified a tolerable dose of romidepsin and indicated that romidepsin has an acceptable toxicity profile with clinically meaningful, efficacy in Japanese patients with R/R PTCL. The efficacy and safety data were comparable with results from other romidepsin phase II studies. Disclosures Ogura: Celltrion, Inc.: Consultancy, Honoraria; SymBio Pharmaceuticals: Consultancy, Honoraria. Maruyama:Janssen: Honoraria; Takeda: Honoraria. Tobinai:Chugai Pharma: Research Funding; Daiichi Sankyo Co., Ltd.: Consultancy; Mundipharma KK: Honoraria, Research Funding; SERVIER: Research Funding; HUYA Bioscience: Honoraria; Celgene: Research Funding; Kyowa Hakko Kirin: Research Funding; GlaxoSmithKline: Research Funding; Janssen Pharmaceuticals: Honoraria, Research Funding; Abbvie: Research Funding; Takeda: Honoraria, Research Funding; Zenyaku Kogyo: Honoraria; Eisai: Honoraria, Research Funding; Ono Pharmaceutical: Research Funding. Uchida:SymBio Pharmaceuticals: Research Funding. Hatake:Chugai: Research Funding; Meiji-Seika: Consultancy; Otsuka: Consultancy; Kyowa Kirin: Honoraria, Research Funding. Tsukasaki:Daiichi Sankyo Co., Ltd.: Consultancy; Takeda: Research Funding. Ishida:Celgene KK: Research Funding; Kyowa Hakko Kirin, Co., Ltd.: Honoraria, Research Funding; Bayer Pharma AG: Research Funding. Ishizawa:SymBio Pharmaceuticals: Research Funding. Laille:Celgene: Employment, Equity Ownership. Ro:Celgene: Employment, Equity Ownership. Tamakoshi:Celgene: Employment, Equity Ownership. Sakurai:Celgene: Employment. Ohtsu:Celgene: Employment, Equity Ownership.

Background Obinutuzumab (GA101) is a novel humanized, glycoengineered Type II anti-CD20 monoclonal antibody. It has greater direct cell death induction and antibody-dependent cell-mediated cytotoxicity and lower complement-dependent cytotoxicity than Type I anti-CD20 antibody rituximab. Studies of obinutuzumab in patients (pts) with previously untreated or relapsed/refractory NHL demonstrated clinical activity with an acceptable safety profile. Infusion-related reactions (IRRs) were the most common adverse event, typically associated with the first infusion. Obinutuzumab 1000 mg is being administered over 4 hrs 15 min for the first infusion on Cycle 1 Day 1, and over 3 hrs 15 min for subsequent infusions. Shortening administration times can result in greater patient convenience and more efficient use of infusion facilities. To evaluate the tolerability of a Shorter Duration of Infusion (SDI), we conducted a Phase II study (JO29737, JapicCTI-152848, 'GATS') of G-CHOP (obinutuzumab in combination with CHOP [cyclophosphamide, doxorubicin, vincristine, prednisolone]) in Japanese pts with previously untreated CD20-positive B-cell NHL. Methods This study included adult pts with previously untreated CD20-positive B-cell NHL. Treatment consisted of 8 cycles of obinutuzumab (1000 mg intravenously on Day 1 of each 21-day cycle, with additional doses on Days 8 and 15 of Cycle 1) plus standard CHOP on Day 1 of Cycles 1-6. Obinutuzumab SDI is administered over 1 hr 30 min. Obinutuzumab was administered as an SDI from Cycle 2 to pts who met the following criteria: (1) No ≥ Gr 3 IRR related to obinutuzumab during regular infusions (RI) in Cycle 1, and (2) Lymphocyte count ≤ 5000/µL in peripheral blood prior to SDI. Primary endpoints were tolerability of SDI, pharmacokinetics (PK) of obinutuzumab. Tolerability of SDI was assessed by incidence of ≥ Gr 3 IRR in Cycle 2. Secondary endpoints were overall safety profile and efficacy. IRRs were defined as AEs related to obinutuzumab occurring during infusion or within 24 hrs from the end of infusion. Results were compared to the multicenter, open-label, randomized GOYA study (phase III, RI G-CHOP), and the multicenter, open-label, single-arm GATHER study (phase II, SDI G-CHOP). The GOYA study included 111 Japanese pts. Results At database lock date, 35 pts were enrolled and treated, including 19 diffuse large B-cell lymphoma, 13 follicular lymphoma, and 3 other histologies; median age was 66 yrs (range, 35-78); 12/35 female; Ann Arbor stage I 11.4%, II 25.7%, III 20.0%, IV 42.9%; 7/35 positive bone marrow involvement. In 7 pts, treatment was prematurely discontinued due to AE (n=3; infected dermal cyst, bronchiolitis, and pneumonia aspiration, 1 pt each), progressive disease (n=2), or physician's decision (n=2). Thirty-three pts received at least one SDI of obinutuzumab, given in Cycle 2 and subsequent cycles in 31 pts. Overall, 48.6% of pts (17/35) experienced IRRs. They were Gr 1/2 in all cases and occurred most commonly on Day 1 Cycle 1 (RI). No SDI-associated IRR was observed in Cycle 2, and very rare cases (2 pts) were noted in Cycles 6, 7, and 8. IRRs occurring in ≥5% pts were pyrexia (25.7%), chills (8.6%), and nausea, blood pressure increased, and headache (5.7%). Gr ≥3 AEs observed in ≥10% of pts were neutropenia (40.0%), neutrophil count decreased (25.7%), febrile neutropenia (17.1%), and leukopenia (14.3%). Obinutuzumab concentration just after Cycle 2 SDI was the same level as the concentration in Cycle 8. This shows PK reached a steady state at Cycle 2 and was not affected by shortening of administration. From PK analysis in the GATS study, AUC7day was 4170±885 µg·day/mL and t1/2 was 15.4±7.0 day, similar to the GATHER values (AUC7day, 3300±1130 µg·day/mL; t1/2, 23.0±15.9 day) after considering individual variability. No ethnic difference was observed. Overall response rate was 82.9% (29/35) (CR 62.9% [22/35], PR 20.0% [7/35]); 2 pts were not evaluable for response. Conclusions Obinutuzumab can be safely administered as SDI. No SDI-associated IRR was observed in Cycle 2. A few IRRs were observed with SDI in later cycles, but all were tolerable and manageable. RI and SDI have comparable safety, PK, and efficacy profiles in Japanese and non-Japanese. Disclosures Hatake: Meiji-Seika: Consultancy; Kyowa Kirin: Honoraria, Research Funding; Otsuka: Consultancy; Chugai: Research Funding. Izutsu:Abbvie: Research Funding; Gilead: Research Funding; Celgene: Research Funding; Janssen Pharmaceutical K.K.: Honoraria; Eisai: Honoraria; Kyowa Hakko Kirin: Honoraria; Chugai Pharmaceutical: Honoraria, Research Funding; Takeda Pharmaceutical: Honoraria; Mundipharma KK: Research Funding. Kinoshita:Janssen: Honoraria; Solasia: Research Funding; Eisai: Honoraria, Research Funding; Ono: Research Funding; Gilead: Research Funding; Kyowa Kirin: Honoraria; Zenyaku: Honoraria, Research Funding; Takeda: Research Funding; Chugai: Honoraria, Research Funding. Tobinai:Kyowa Hakko Kirin: Research Funding; Ono Pharmaceutical: Research Funding; HUYA Bioscience: Honoraria; Chugai Pharma: Research Funding; Eisai: Honoraria, Research Funding; Daiichi Sankyo Co., Ltd.: Consultancy; Celgene: Research Funding; GlaxoSmithKline: Research Funding; Zenyaku Kogyo: Honoraria; SERVIER: Research Funding; Abbvie: Research Funding; Takeda: Honoraria, Research Funding; Mundipharma KK: Honoraria, Research Funding; Janssen Pharmaceuticals: Honoraria, Research Funding.

Epigenetic program is a molecular basis of cellular identity and functions. We have shown the transcriptome (Cancer Cell, 2012) and the underlying histone methylation patterns (Blood, 2016) of adult T-cell leukemia-lymphoma (ATL). The epigenetic landscape of ATL is defined as "genome-wide H3K27me3 accumulation". Similar accumulation has been detected in multiple cancers, particularly in hematological malignancies. Relief of the cumulative methylation may restore the aberrant transcriptome to ideal expression signature, leading to a promising treatment. Due to variation characteristics, EZH2 is recognized as a druggable target. However, extrinsic regulation of methylation pattern is still challenging without knowledge of molecule(s) and their combination that needs to be targeted to reprogram the epigenome in anticipation of synthetic lethality. To redefine the conventional concept, we first examined expression and global occupancy patterns of H3K27 methyltransferases EZH1 and EZH2. EZH2 expression was low in CD4+ T cells and significantly high in ATL. In contrast, basal EZH1 was very high in mature lymphocytes compared with undifferentiated lineages and also high in ATL. ChIP-on-chip analysis revealed significant changes in distributions of both EZH1 and EZH2 in primary ATL cells, which caused abnormal H3K27me3 accumulation. Importantly, over 80% of H3K27me3 are specifically induced by either EZH1 (28.9%) or EZH2 (14.4%), or by both (39.3%). Moreover, they have differential functions by regulating specific targets; EZH2 suppresses various transcription regulators, establishing complex gene regulatory network. EZH1 would rather directly induce H3K27me3 at genes involving functional processes such as lymphocyte activation. We detected EZH1 and EZH2 in functional polycomb repressive complex 2 (PRC2) in ATL and DLBCL cells. Unexpectedly, EZH1/2 were co-localized with H3K4me3 at a small population of the lymphoma genome. The "EZH1/2 + H3K4me3" non-canonical targets such as cell cycle activators were highly expressed in ATL. We next compared functions of EZH1/2. Single depletion of EZH1 or EZH2 suppressed T- and B-lymphoma cell proliferation, which supports their unique functions. The broad reduction of H3K27me3 was achieved by EZH2 inhibition; however, genome-wide ChIP demonstrated that EZH2 inhibition or depletion triggered strong compensatory action of EZH1, followed by rebound accumulation of H3K27me3 at many functional genes in EZH1+ lymphoma cells. We found that a transcription factor YY1 affects PRC2 recruitment and EZH1 compensation after EZH2 inhibition. Double depletion of EZH1+EZH2 or YY1+EZH2 surmounted the epigenetic homeostasis. In addition, depletion of EZH1 significantly enhanced effects of EZH2 inhibitors in ATL and DLBCL cells (5.47~205-fold). These data indicate requirements for the aberrant epigenome, namely, fluctuating EZH2 (upregulation or mutation) and underlying stable EZH1. We have succeeded in developing an unprecedented EZH1/2 dual-inhibitor (IC50 9.0 nM (EZH1); 10 nM (EZH2)). The new drug successfully inhibited genome-wide EZH1/2 occupancies without compensation, resulting in effective H3K27me3 reduction and gene reactivation compared with the single inhibitor. Of note, the dual-inhibitor suppressed expression of the non-canonical EZH1/2 + H3K4me3 target genes. Besides H3K27me3 reprogramming, EZH1/2 inhibition could modulate genes through H3K4me3 regulation and indirect influence on the secondary regulatory network and signaling pathways such as NF-kB. The EZH1/2 dual-inhibitor significantly blocked primary ATL cell survival and in vivo tumor growth of ATL and DLBCL models. Furthermore, we evaluated drug efficacy in various models of hematological malignancies including ATL, DLBCL (EZH2 WT and mutant), Burkitt lymphoma, and PTCL, which are all originated from EZH1+ differentiated lymphocytes. All of them showed higher sensitivity against the EZH1/2 inhibitor compared with the EZH2 solo inhibitor (5.2~200-fold). We did not detect strong adverse effects in normal T cells. These integrated molecular and phenotypic analyses provide a novel concept "EZH1+EZH2 dual-targeting" and demonstrate validity of the new drug in the treatment of malignant lymphomas. Taking these results, a Phase I clinical trial against T- and B-cell non-Hodgkin lymphomas including ATL is now under way in Japan. Disclosures Yamagishi: Daiichi Sankyo Co., Ltd.: Research Funding. Honma:Daiichi Sankyo Co., Ltd.: Employment. Adachi:Daiichi Sankyo Co., Ltd.: Employment. Ohsugi:Daiichi Sankyo Co., Ltd.: Research Funding. Utsunomiya:Daiichi Sankyo Co., Ltd.: Speakers Bureau. Tsukasaki:Daiichi Sankyo Co., Ltd.: Consultancy; Takeda: Research Funding. Tobinai:Zenyaku Kogyo: Honoraria; Takeda: Honoraria, Research Funding; Mundipharma KK: Honoraria, Research Funding; Kyowa Hakko Kirin: Research Funding; Celgene: Research Funding; Daiichi Sankyo Co., Ltd.: Consultancy; SERVIER: Research Funding; Ono Pharmaceutical: Research Funding; Eisai: Honoraria, Research Funding; Chugai Pharma: Research Funding; Abbvie: Research Funding; Janssen Pharmaceuticals: Honoraria, Research Funding; GlaxoSmithKline: Research Funding; HUYA Bioscience: Honoraria. Araki:Daiichi Sankyo Co., Ltd.: Employment.

Background: Adult T-cell leukemia-lymphoma (ATL) is a rare and refractory malignancy of regulatory T /TH2 cell associated with human T-lymphotropic virus type I (HTLV-1). In recent years, the introduction of intensive chemotherapy, allogeneic hematopoietic stem cell transplantation (Allo-HSCT), and mogamulizumab (anti-CCR4 antibody, which was approved in Japan in May 2012 for relapsed/refractory ATL, and in Dec. 2014 for newly diagnosed ATL) are expected to improve the prognosis of ATL. Meanwhile, the aging tendency of the ATL patient population has been recognized recently in Japan. Therefore, for the development of future treatment strategies for ATL, it is important to assess the therapeutic utilization and prognosis in patients with ATL not only in clinical trials but also in clinical practices. Aim: To report the current clinical features and outcomes of patients with ATL who were newly diagnosed during 2010-2011 from 114 hospitals in Japan. Methods: A questionnaire for each of 996 patients was sent to the hospitals, requesting information on treatment options and outcomes in detail. Statistical analysis was undertaken using Chi-squared tests to identify significant differences in the proportion, and using Kaplan-Meier curves to estimate the probability of overall survival (OS) with the log-rank test to identify significant differences in the probability, according to age, subtypes, and initial treatment. Results: We received 94.7% response rate from hospitals. Among 800 patients registered in this prognosis survey, 45 patients were not assessable for outcomes because of insufficient data, therefore, 755 (male 397, female 355, unknown 3) were included in the outcome analysis. The median age at diagnosis was 68 years old for all and the median follow-up time was 49 months for survivors. The distributions of ATL subtypes according to Shimoyama criteria were 382 (51%) for acute, 192 (25%) for lymphoma, 86 (11%) for chronic, and 95 (13%) for smoldering types, respectively. The median survival time and 2-year survival rate were: acute (n=377) (264 days, 24%), lymphoma (n=212) (293 days, 26%), chronic (n=71) (1,094 days, 56%), and smoldering (n=99) (1,900 days, 80%), respectively. Overall, the initial therapy-regimens used for aggressive ATL (acute and lymphoma subtypes) were VCAP-AMP-VECP-like regimen in 49%, CHOP-like regimen in 42%, and others in 9%. However, the utilization percentage of each option varied with age, VCAP-AMP-VECP-like regimen was used 68% of those aged 65 or younger but 32% of those over 65, respectively. CHOP-like regimen was used 29% for those aged 65 or younger but 52% for those over 65, respectively. Allo-HSCT for aggressive ATL was performed about 50% for those aged 55 or younger, 30% for those aged 56-65, but only 1% for those aged over 66, respectively. A total of 75 (10%) patients were treated with mogamulizumab. Fifty-six of them were treated with mogamulizumab after May 2012, when mogamulizumab was approved and generally adopted in Japan. When comparing the OS by pre- or post- general adoption of mogamulizumab, the 2-year OS was significantly worse in those treated after general adoption (18%) than those before (61%). When the response to initial chemotherapies was poor, the prognosis was worse regardless of treatment options, i.e., chemotherapy, allo-HSCT, and mogamulizumab. Response rate to initial chemotherapy differed by age, i.e., the older the age, the worse the response rate. Conclusion: This work highlights the difference in the treatment and the prognosis by age in patients with ATL in the current clinical practice in Japan. Intensive chemotherapy and allo-HSCT are not fully applicable for the elderly patients, who account for more than half of the ATL patients. Better strategies are required to improve clinical outcomes of the primary treatment, especially of the elderly ATL patients. Funding : This work was supported by Health and Labor Science Research Grant, Grant Number H26-ganseisaku-ippan-006. Disclosures Utsunomiya: Daiichi Sankyo Co., Ltd.: Speakers Bureau. Tobinai:Kyowa Hakko Kirin: Research Funding; Eisai: Honoraria, Research Funding; Abbvie: Research Funding; Chugai Pharma: Research Funding; Janssen Pharmaceuticals: Honoraria, Research Funding; Zenyaku Kogyo: Honoraria; Celgene: Research Funding; GlaxoSmithKline: Research Funding; Ono Pharmaceutical: Research Funding; SERVIER: Research Funding; HUYA Bioscience: Honoraria; Mundipharma KK: Honoraria, Research Funding; Takeda: Honoraria, Research Funding; Daiichi Sankyo Co., Ltd.: Consultancy. Tsukasaki:Daiichi Sankyo Co., Ltd.: Consultancy; Takeda: Research Funding.

Background: HBI-8000 is an orally bioavailable member of the benzamide class of histone deacetylase inhibitors (HDACi), that inhibits cancer-associated HDAC enzymes (Class I and IIb). HBI-8000 has anti-tumor activity through various mechanisms of action, including epigenetic reprogramming and immunomodulation. It was recently approved by the Chinese FDA under the name chidamide (Epidaza) for relapsed or refractory (R/R) peripheral T-cell lymphoma (PTCL) with a recommended dose of 30 mg twice weekly (BIW). HBI-8000 is also being manufactured in the USA for clinical development outside of China. The preliminary results of a phase I trial of HBI-8000 to confirm the safety and maximum tolerated dose (MTD) in Japanese patients (pts) with advanced NHL are presented (NCT02697552). Methods: This is a multicenter, prospective phase I trial in Japan. Inclusion criteria: patients are eligible if they have histologically or cytologically proven NHL and no other standard therapy is available. The primary endpoint is the MTD based on the frequency of dose-limiting toxicities (DLTs) observed within 28 days of the first dose. Secondary endpoints include pharmacokinetic (PK) profile and anti-tumor activity. At the time of this abstract submission, the trial is still ongoing. Results: Thirteen out of 14 pts were eligible for the 1st cycle DLT assessment (6 pts in the 30 mg, 7 pts in the 40 mg cohort). Median age was 68 years, gender well balanced, and the majority of pts had ≥ 2 prior treatment regimens. Five pts had the diagnosis of adult T-cell leukemia-lymphoma (ATL), 2 pts presented with PTCL, 3 with diffuse large B-cell lymphoma (DLBLC), 2 with follicular lymphoma (FL), 1 with cutaneous T-cell lymphoma (CTCL), and 1 with marginal zone lymphoma. Overall, the treatment was well tolerated, and adverse drug reactions (ADRs) were predominantly hematologic, consistent with the previous experiences. There were 7 pts in the 40 mg dose cohort because one of the first 3 pts had to be replaced for incomplete dosing due to grade 3 hypertriglyceridemia which was not regarded as DLT by the Data Monitoring Safety Committee (DMC/SMC). In the 40 mg cohort, 2 pts were considered as DLTs by definition in the protocol: grade 4 neutropenia and grade 3 alanine transaminase (ALT) increase. Both pts were asymptomatic. The grade 4 neutropenia promptly resolved with the administration of G-CSF and the grade 3 ALT elevation resolved with dose interruption. The 30 mg dose cohort completed with no DLT after the 1st cycle in 6 pts. The following hematologic grade 3/4 toxicities were noted in the 40 mg dose cohort (N=7): leukopenia (2 pts, 29%), neutropenia (3 pts, 43%), and thrombocytopenia (3 pts, 43%). Non-hematologic ADRs included fatigue, nausea, diarrhea, decreased appetite, erythema and pyrexia. The preliminary pharmacokinetic (PK) results from the 3 patients in the 30 mg cohort, and 7 patients in the 40 mg dose cohort show inter-patient variability as expected of an oral agent. Mean half-life (t ½ ) was between16.5 and 20 hours (h) with a Tmax between 2.5 and 3.5h and consistent with previous findings. Mean Cmax and AUC increased with dose (30 mg: 210 ng/mL; 3660 h*ng/mL and 40 mg: 590 ng/mL; 7200 h*ng/mL). The patient with neutropenia as DLT presented with the highest exposure. Cardiovascular assessments including serial ECGs and troponin assessments did not reveal clinically relevant findings. Best overall response was noted in 40 mg BIW cohort (N=7): 1 CR (10%), 5 PR (30%), 1 SD (20%). Four of the partial responders were ATL patients. In the 30 mg BIW dose cohort, 4/6 patients had stable disease after the 1st cycle. Summary: In this phase l trial evaluating the safety of twice weekly 30 mg and 40 mg doses, HBI-8000 was well tolerated with expected toxicities that could be managed with dose interruptions/reductions. Tumor response results in pts who completed at least one cycle of treatment indicate some clinical benefit especially in pts who started with the 40 mg dose level. The DMC/SMC has provided an opinion that the 2 observed DLTs with HBI-8000 in the phase I trial were clinically manageable and that 40 mg BIW would be recommended as the dosage for subsequent phase II studies. Registration enabling phase II trials to evaluate efficacy and safety in R/R ATL pts (Japan) and R/R PTCL pts (Japan and Korea) are being initiated. Disclosures Ando: SymBio Pharmaceuticals: Research Funding. Yoshimitsu:HUYA Bioscience International: Research Funding. Ishida:Kyowa Hakko Kirin, Co., Ltd.: Honoraria, Research Funding; Celgene KK: Research Funding; Bayer Pharma AG: Research Funding. Hidaka:Chugai-pharm: Research Funding. Nagashima:HUYA Bioscience International: Employment. Miyazato:HUYA Bioscience International: Employment. Schupp:HUYA Bioscience International: Employment. Rolland:HUYA Bioscience International: Employment. Gillings:HUYA Bioscience International: Employment. Lee:HUYA Bioscience International: Employment. Tobinai:Eisai: Honoraria, Research Funding; GlaxoSmithKline: Research Funding; HUYA Bioscience: Honoraria; Janssen Pharmaceuticals: Honoraria, Research Funding; Kyowa Hakko Kirin: Research Funding; Mundipharma: Honoraria, Research Funding; Ono Pharmaceuticals: Research Funding; Servier: Research Funding; Takeda: Honoraria, Research Funding; Zenyaku Kogyo: Honoraria; Chugai Pharma: Research Funding; Celgene: Research Funding; Abbvie: Research Funding.

Introduction:Central nervous system invasion in multiple myeloma (CNS-MM) is extremely rare (approximately 1% of MM). Prognosis of patients with CNS-MM is generally poor, and the median overall survival (OS) time from its diagnosis (Dx) has been reported to be 2 to 7 months. However, because of its rareness, most available data concerning CNS-MM are based on anecdotal reports on small case series. In this study, we retrospectively collected clinical data of Japanese patients with CNS-MM and analyzed them to reveal clinical features and prognosis of this disease entity. Methods:We conducted a nationwide multicenter retrospective study involving 107 centers that consist of educational facilities authorized by Japanese Society of Hematology and its related hospitals. CNS-MM was defined based on the previously reported criteria (Br J Haematol 2013;162:483-48). Univariate and multivariate analyses were performed to explore prognostic factors and the suitable treatment of CNS-MM. Results:From December 1978 to February 2016, 75 patients with CNS-MM were identified. The median age was 58 (range: 32-77 years). CNS invasion was detected at initial Dx of MM in 4% and at relapse in 96%. The median time from Dx of MM to that of the secondary CNS-MM was 1.8 years. Concomitant plasma cell leukemia (18%), skull plasmacytoma (12%), and myeloma cells in the cerebrospinal fluid (63%) were observed at the Dx of CNS-MM. Common symptoms of CNS-MM included consciousness disturbance (37%), cranial nerve palsy (25%), diplopia (18%), headache (16%), spinal nerve disorder (13%), and nausea/vomiting (12%). Intrathecal chemotherapy (IT) was used in 37%, cranial and/or spinal irradiation therapies (RTx) in 45% in addition to various systemic therapies, which included immunomodulatory drugs (IMiDs) (21%), bortezomib (19%), alkylators (21%), dexamethasone alone (6%), autologous stem cell transplant (auto-SCT, 4%), and allogeneic stem cell transplant (allo-SCT, 3%). With a median follow-up of 3.4 months from Dx of CNS-MM and of 31.5 months from that of MM, the median OS time from Dx of CNS-MM was only 3.7 months. The median OS times for the 12 untreated and 61 treated patients were 0.2 and 5.1 months, respectively (P < 0.01), suggesting that the patients who did not receive any treatments (Txs) were in a severe condition and their prognoses were extremely poor. In univariate analyses for the entire group, absence of both atypical lymphocytes and plasma cells in the peripheral blood at Dx of MM and no Tx for MM before Dx of CNS-MM were significantly favorable prognostic factors (P = 0.008 and P < 0.0001, respectively). Regarding Tx for CNS-MM patients who received any Txs (conventional chemotherapies, bortezomib, IMiDs, IT, and RTx), only RTx was correlated with longer OS time (P = 0.047). In multivariate analyses, RTx and IT had a significant impact on longer OS time (>6 months, OR = 3.80, 3.97, P = 0.002, 0.01, respectively). Although the prognosis of CNS-MM in this study cohort was very poor, seven patients could survive for >1 year from Dx of CNS-MM. Among them, RTx, IMiDs, IT, bortezomib, auto-SCT, and allo-SCT were given to 5, 4, 5, 3, 1, and 1 patients, respectively. Conclusions:Prognosis of CNS-MM is extremely poor in general. Although there must be a selection bias that patients who received various salvage Txs for CNS-MM were in a better condition, the results of our study suggest that multi-modality Txs with RTx, IT, and IMiDs/bortezomib may prolong the survival time in some cases. Prospective studies are needed to confirm our preliminary observations. Disclosures Takamatsu: Celgene: Honoraria; Janssen Pharmaceuticals: Honoraria. Sunami:Janssen Pharmaceutical: Research Funding; Sanofi: Research Funding; Daiichi Sankyo: Research Funding; Bristol-Myers Squibb K.K.: Research Funding; Novartis: Research Funding; Celgene: Honoraria, Research Funding; Takeda: Research Funding; Ono Pharmaceutical: Research Funding. Hagiwara:Takeda: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees. Kuroda:Janssen: Honoraria; Bristol Myers Squibb: Honoraria, Research Funding; Astra Zeneca: Research Funding; Celgene: Honoraria, Research Funding. Murakami:Bristol Meyers Squibb: Honoraria; Astellas: Honoraria; Mochida: Honoraria; Eisai: Honoraria; Takeda: Honoraria; MSD: Honoraria; Chugai: Honoraria; Celgene: Honoraria. Nakao:Alexion Pharmaceuticals: Honoraria, Research Funding. Tobinai:Celgene: Research Funding; Mundipharma KK: Honoraria, Research Funding; Eisai: Honoraria, Research Funding; Takeda: Honoraria, Research Funding; SERVIER: Research Funding; HUYA Bioscience: Honoraria; Kyowa Hakko Kirin: Research Funding; Zenyaku Kogyo: Honoraria; Chugai Pharma: Research Funding; Abbvie: Research Funding; GlaxoSmithKline: Research Funding; Ono Pharmaceutical: Research Funding; Daiichi Sankyo Co., Ltd.: Consultancy; Janssen Pharmaceuticals: Honoraria, Research Funding. Iida:Celgene: Honoraria, Research Funding; Janssen Pharmaceuticals: Honoraria, Research Funding.

[Graphic][1] Introduction: Adult T-cell leukemia-lymphoma (ATL), a distinct subtype of peripheral T-cell lymphoma (PTCL), is caused by human T-lymphotropic virus type-I (HTLV-1). Although rare in the rest of the world, ATL accounts for 25% of PTCL cases diagnosed in Japan, where ATL cases are clustered in areas endemic for HTLV-1 infection. Studies of lenalidomide, an oral immunomodulatory agent that has antiproliferative and direct antineoplastic activity in cutaneous T-cell lymphoma and PTCL, have reported encouraging clinical activity. On the basis of the results from the ATLL-001 dose-finding study of lenalidomide (Uike et al. ASH 2012. Abstract 2737), this multicenter phase II study (ATLL-002) was designed to investigate the efficacy and safety of single-agent lenalidomide in Japanese patients with relapsed ATL. Methods: Patients with relapsed acute, lymphoma, or the unfavorable chronic subtype of ATL who were at least 20 years of age, had ECOG performance status 0-2, no prior allogeneic stem cell transplant, and who had failed at least 1 chemotherapy were included in the study. Patients refractory to their last prior therapy were excluded. Treatment consisted of oral lenalidomide 25 mg/day administered continuously until disease progression or unacceptable toxicity. The primary endpoint was overall response rate (ORR). The secondary endpoints were progression-free survival (PFS), duration of response (DOR), overall survival (OS), and safety. Response was assessed by central review using the criteria proposed by Tsukasaki et al in their international consensus report (J Clin Oncol. 2009;27:453-459.); safety was assessed per NCI CTCAE v4.0 criteria. The estimated number of patients required was 25, for 90% power to detect a lower limit of the 95% confidence interval (CI) exceeding the 5% threshold of ORR, based on the assumptions that the minimum required ORR to a new drug for relapsed or recurrent ATL is 5% and the expected ORR to lenalidomide is 25%. Results: Twenty-six patients were enrolled and received lenalidomide. The median age was 68.5 years (range, 53-81), with 15 (58%) acute, 7 (27%) lymphoma, and 4 (15%) unfavorable chronic type ATL patients. Patients had received a median of 2 (range, 1-4) prior chemotherapeutic or antibody agents for ATL, 11 (42%) of whom received prior mogamulizumab (anti-CCR4 antibody). At a median 3.8-month follow-up, lenalidomide met the primary endpoint by exhibiting an ORR of 42% (11/26; 95% CI, 23-63) (acute 33% [5/15], lymphoma 57% [4/7], unfavorable chronic 50% [2/4]), including 5 (19%) complete responses (CR)/CR unconfirmed (95% CI, 7 to 39; Table 1). Stable disease was 31%, and progressive disease was 27%. The median time to response was 1.9 months (95% CI, 1.8 to 3.7). Although the data were immature at the time of analysis, median DOR for all responders was not reached (NR) (95% CI, 0.5 months to NR), median PFS was 3.8 months (95% CI, 1.9 months to NR), and median OS was 20.3 months (95% CI, 9.1 months to NR). At the time of the data cut-off, 5 (19%) patients remained on lenalidomide treatment. The most common grade 3/4 adverse events (AEs), accounting for at least 10% of all cases, were neutropenia (65%), leukopenia (39%), lymphopenia (39%), thrombocytopenia (23%), anemia (19%), and hypokalemia (12%). Serious AEs were reported in 9 (35%) patients; only thrombocytopenia (2 patients [8%]) was observed in >1 patient. AEs led to dose reduction/interruption in 17 (65%) patients and study discontinuation in 6 (23%). Seven deaths occurred during the study, 6 due to disease progression and 1 due to pneumonia unrelated to lenalidomide treatment. Conclusions: In this multicenter, open-label, phase II study, lenalidomide monotherapy demonstrated a 42% ORR and acceptable tolerability profile. These results support the potential for lenalidomide monotherapy becoming a treatment option for patients with relapsed ATL. | ATL type | All patients (N = 26) | Acute (n = 15) | Lymphoma (n = 7) | Unfavorable chronic (n = 4) | | ------------- | ------------------------------ | ----------------------- | ------------------------- | --------------------------- | | ORR, n (%) | 11 (42) | 5 (33) | 4 (57) | 2 (50) | | CR/CRu, n (%) | 5 (19) | 3 (20) | 2 (29) | | | PR, n (%) | 6 (23) | 2 (13) | 2 (29) | 2 (50) | | SD, n (%) | 8 (31) | 6 (40) | | 2 (50) | | PD, n (%) | 7 (27) | 4 (27) | 3 (43) | | * CR, complete response; CRu, CR unconfirmed; ORR, overall response rate; PD, progressive disease; PR, partial response; SD, stable disease. Table. Best response to lenalidomide in relapsed ATL Disclosures Fujiwara: Celgene: Honoraria, Other: Research funding to my institution; travel, accommodations, expenses. Off Label Use: Lenalidomide to treat ATL. Ishida: Celgene K.K.: Other: Research Funding to my institution; Bayer Pharma AG: Other: Research Funding to my institution; Kyowa Hakko Kirin Co., LTD: Honoraria, Other: Research Funding to my institution. Moriuchi: Celgene: Other: Research Funding to my institution; travel, accommodations, expenses, Speakers Bureau. Jo: Celgene: Honoraria; Janssen: Honoraria; Takeda: Honoraria; Kyowa Kirin: Honoraria; Nippon Shinyaku: Honoraria. Ishizawa: Kyowa Kirin: Research Funding; Celgin: Research Funding; Janssen: Research Funding; Takeda: Research Funding; GSK: Research Funding; Takeda: Speakers Bureau; Kyowa Kirin: Speakers Bureau; Pfizer: Speakers Bureau; Celgin: Speakers Bureau. Tobinai: Gilead Sciences: Research Funding. Tsukasaki: Celgene: Consultancy, Research Funding; Takeda: Consultancy, Research Funding; Chugai: Consultancy, Research Funding; Novartis: Research Funding; Pfizer: Research Funding; Mundipharma: Research Funding; Kyowa Kirin Hakkou: Research Funding. Ogura: Mundipharma: Consultancy, Research Funding; MeijiSeika Pharma: Consultancy; Zenyaku: Research Funding; Eisai: Research Funding; Pfizer: Research Funding; Janssen: Research Funding; Celgene: Research Funding; Solaisia: Research Funding. Midorikawa: Celgene K.K.: Employment; Celgene Corporation: Equity Ownership. Ruiz: Celgene K.K.: Employment. Ohtsu: Celgene: Employment, Equity Ownership, Other: travel, accommodations, expenses. [1]: /embed/inline-graphic-2.gif

Introduction: Adult T-cell leukemia-lymphoma (ATL) is a distinct peripheral T-cell lymphomacaused by human T-lymphotropic virus type I (HTLV-1), which is endemic in Japan. Only a small percentage of HTLV-1 carriers infected through breast-feeding develop the disease. Previous nationwide surveys during 1980s-2000s in Japan provided a comprehensive view on the clinio-epidemiological profiles of ATL, including the establishment of the subtype-classification (i.e., the Shimoyama criteria: acute, lymphoma, chronic, and smoldering type) based on the diversity of the clinical features and prognosis. Treatment strategies have been developed by the subtype-classification; watchful waiting for indolent ATL, intensive chemotherapy followed by allogeneic hematopoietic stem cell transplantation (allo-HSCT) for aggressive ATL. The aim of this 11th survey is to characterize the current clinio-epidemiological features of ATL in Japan in the light of previous surveys. Methods: In 2013-14, we conducted an anonymous, cross-sectional, hospital-based survey of patients with ATL who were newly diagnosed during 2010-2011 across Japan. First, we asked 2500 hospitals with departments of hematology and dermatology to participate in this survey, and then we sent questionnaires to 128 participating hospitals to accumulate data of ATL. Skilled five hematologists reviewed the data of each questionnaire sheet, and the agreements of ATL diagnosis including the subtypes between the central review and participating hospitals were evaluated using Kappa statistics. Most of the collected data were analyzed by descriptive statistics. Results: A total of 996 ATL patients were registered; of these, 41 were eliminated because of the insufficient information for the diagnosis of ATL. Overall diagnostic agreement on subtype of ATL was substantial, with a kappa value 0.71 (standard error, 0.021); most of the disagreement was within aggressive/indolent category, acute vs. lymphoma types or acute vs. unfavorable chronic types. Among the 955 evaluable patients (M/F ratio, 1.12), 70% were diagnosed in the southwest region of Japan (Kyusyu/Okinawa) where HTLV-1 is endemic, which was consistent with the past surveys. The mean age at diagnosis was 68.3 years (median 68.8, range 24.7-100.3), which was significantly higher than 60.3 years in 1994-1995 and 57.7 years in 1986-1987. The proportion of ATL patients aged over 65 years was 79 % in this survey (whereas, 48% in the 1990-1991 survey), which indicates that the allo-HSCT is not applicable to the majority of current ATL patients in Japan. The proportion of acute, lymphoma, chronic, and smoldering types was 48, 28, 10 and 13%, respectively. The proportion of smoldering and chronic types tended to be greater than previous surveys (7% and 10% in the 1988-1997 surveys combined). The proportion of subtype by age group in this survey showed that the older in age at diagnosis are, the higher proportion of lymphoma subtype (10% in those aged younger than 40 years, 20% in those 50-59, and 31% in those 70 years or older. Discussion: This 11th survey revealed several clinio-epidemiological features of current ATL in Japan different from those in past two decades. First, a considerably increasing proportion of elderly ATL patients were diagnosed, which may be expected from a recent distribution of nationwide HTLV-1 carriers in Japan (Satake, et al, 2011). Second, there is an increasing tendency in the proportion of indolent types of ATL. This may be partly influenced by participation of the dermatology departments for the first time, because early phase of ATL localized in skin were frequently diagnosed in the dermatology department. Third, the proportion of lymphoma subtype was increased with age, which suggests that aging-related unknown mechanisms may affect the subtype distribution. More detailed analysis and subsequent surveys are planned to further evaluate clinical features and the efficacy of modern therapies on prognosis of ATL. Disclosures Ishizawa: Kyowa Kirin: Speakers Bureau; GSK: Research Funding; Takeda: Research Funding; Celgin: Speakers Bureau; Kyowa Kirin: Research Funding; Celgin: Research Funding; Janssen: Research Funding; Takeda: Speakers Bureau; Pfizer: Speakers Bureau. Ishida:Bristol-Myers Squibb: Honoraria. Ishida:Kyowa Hakko Kirin Co., LTD: Honoraria, Other: Research Funding to my institution; Bayer Pharma AG: Other: Research Funding to my institution; Celgene K.K.: Other: Research Funding to my institution. Tobinai:Gilead Sciences: Research Funding. Watanabe:Daiichi Sankyo Co., Ltd.: Research Funding.

Adult T-cell leukemia/lymphoma (ATL) is a distinct subtype of peripheral T-cell neoplasms associated with human T-cell leukemia virus type-1 retrovirus. ATL includes a heterogeneous group of patients in terms of pathological and clinical features as well as prognosis, suggesting the presence of underlying molecular pathogenesis that could explain such heterogeneity among patients. Recently, we performed an integrated molecular analysis of a large number of ATL cases and delineated a comprehensive registry of gene mutations and other genetic/epigenetic lesions in ATL. In this study, we investigated possible correlations between these genetic/epigenetic lesions and clinical/pathological phenotypes in a large set of ATL patients, with a special focus on the impact of mutations and copy number alterations (CNAs) on clinical outcome. We analyzed a total of 361 ATL samples, including acute (n = 192), lymphoma (n = 66), chronic (n = 89), and smoldering (n = 14) subtypes, for recurrent mutations and CNAs. Each subtype had characteristic genetic/epigenetic features, suggesting a distinct molecular pathogenesis therein. Aggressive (acute and lymphoma) subtypes were characterized by a higher number of mutations and CNAs including focal amplifications/deletions, hyperploid status, and CIMP phenotype, compared with indolent (chronic and smoldering) tumors. Two mutations (TP53 and IRF4) and eight focal deletions involving 1p13 (CD58), 6p21 (HLA-B), 9p21 (CDKN2A), 10p11 (CCDC7), 13q32 (GPR183), 16q23 (WWOX), 17p13 (TP53), and 19q13 (CEBPA), were more common in aggressive ATL than in indolent ATL. In contrast, showing a similar mutational distribution to those found in large granular lymphocytic leukemia, STAT3 mutations were characteristic of the indolent diseases. Gene set enrichment analysis of RNA-seq data showed a significant enrichment of MYC pathway and genes regulating cell cycle and DNA repair in upregulated genes in aggressive ATL. Next, we assessed the impact of mutations and CNVs on prognosis among 215 ATL cases, for which survival data were available. In the entire cohort, mutation in CCR4 and IRF4, focal amplification in 9p24 (CD274) and 14q32 (BCL11B), and focal deletion in 9p21 (CDKN2A) were found to be significant predictors of poor overall survival, after adjustment for disease subtype and age. Multivariate analysis revealed that disease subtype (aggressive vs. indolent) was the most significant predictor of clinical outcome in ATL. Subsequent multivariate analysis according to disease subtype showed that within the patients with aggressive ATL, older age (≥ 70 years), CCR4 mutations, and 9p24 amplification were independently associated with an adverse outcome. Based on the number of the risk factors they owned, patients with aggressive ATL were classified into three categories showing marked difference in 3-year overall survival (OS) (P < 0.001): those with no risk factors (OS, 32%), with one risk factor (18%), and with two or more (0%). Among the patients with indolent ATL, we found IRF4 and TP53 mutations, 9p24 amplification, and deletions in 9p21 and 10p11 were independently associated with reduced survival. Interestingly, these alterations, except for 9p24 amplification, were also identified as genes more frequent in aggressive ATL. More importantly, based on these risk factors, the patients with indolent ATL can be classified into two categories showing very different prognostic profiles: patients with no risk factors (OS, 89%) and those with one or more risk factors (21%) (P < 0.001, HR = 16.8, 95% CI:5.4-52.5), suggesting that patients with indolent ATL having a genetic feature of the aggressive subtypes might genetically and biologically represent a distinct subset, which should be better managed as having an aggressive disease. Among these poor prognostic factors, 9p24 amplification and CCR4 mutation are especially interesting, because these lesions might be plausible targets of available agents, including anti-PD1/PD-L1 and anti-CCR4 antibodies. In conclusion, based on the comprehensive genetic profiling, we demonstrated that the known subtypes of ATL can be further classified into genetically and biologically distinct subsets of tumors characterized by discrete sets of genetic lesions and substantially different prognosis. Our results suggest that molecular profiling can improve the prediction of prognosis in ATL patients and better guide therapy. Disclosures Tobinai: Gilead Sciences: Research Funding. Miyazaki:Shin-bio: Honoraria; Chugai: Honoraria, Research Funding; Sumitomo Dainippon: Honoraria; Celgene Japan: Honoraria; Kyowa-Kirin: Honoraria, Research Funding. Watanabe:Daiichi Sankyo Co., Ltd.: Research Funding.

Adult T-cell leukemia/lymphoma (ATL) is a peripheral T-cell neoplasm of largely unknown genetic basis, which is associated with human T-cell leukemia virus type-1 (HTLV-1) infection. To delineate a genetic landscape of somatic alterations in ATL, we have performed an integrated genetic study, in which whole-genome/exome (WGS/WES) and transcriptome sequencing (RNA-seq) was performed for a cohort of 83 paired ATL samples, followed by extensive validation using targeted sequencing of detected mutations in 370 follow-up samples. A striking feature of driver lesions in ATL was their strong enrichment in the components of T-cell receptor (TCR) / NF-κB pathway. Accounting for more than 90% of ATL cases, these lesions were characterized by the predominance of activating alterations, including hotspot missense mutations in PLCG1 (36%), PRKCB (33%), CARD11 (24%), VAV1 (18%), IRF4 (14%) and FYN (4%). Among these, most frequently mutated was PLCG1, which encodes phospholipase C γ1 (PLCγ1), a key regulator of the proximal TCR signaling. Besides the S345F and S520F mutations recently reported in cutaneous T-cell lymphoma, we identified an additional hotspot mutations (R48W, E1163K, and D1165H). The second most frequently mutated gene was PRKCB, encoding a member of the protein kinase C (PKC) family of proteins (PKCβ), a pivotal signaling molecule downstream of PLCγ. The frequent mutations of PKCβ were unexpected, because it is PKCθ that has been implicated in TCR signaling, whereas PKCβ has been more focused in the context of B-cell receptor signaling. Approximately 93% of the PRKCB mutations were confined to the catalytic domain with a prominent hotspot at D427, suggesting gain-of-function nature of these mutations. Consistent with this, when transduced with the D427N PKCβ mutant, HEK293T and/or Jurkat cells showed increased membrane translocation after PMA/Ionomycin-stimulation, enhanced IKK phosphorylation and p65 nuclear translocation, and augmented NF-κB transcription, compared to wild-type PKCβ-transduced cells. Thus, these PRKCB mutations are the first activating mutations of this family identified in human cancers. Downstream to PKC lies CARD11, a scaffolding protein required for antigen receptor-induced NF-κB activation. Although previously reported in B-cell lymphomas, CARD11 mutations were more common in ATL (24%). In B-cell lymphomas, mutations are largely limited to the coiled-coil (CC) domain, whereas in ATL, they were clustered not only within the CC domain, but also within the PKC-responsive inhibitory domain, showing a prominent mutational hotspot at E626. The inhibitory domain has been implicated in autoinhibition, whose deletion leads to constitutive activation of CARD11. Intriguingly, WGS identified small intragenic deletions confined to this domain (exons 14-17) in 4 cases (8%) without canonical mutations, and RNA-seq confirmed the skipping of the corresponding exons in these cases. Remarkably, CARD11 mutation significantly co-occurred with PRKCBmutations, suggesting potential functional synergism between these lesions. Actually, overexpression of wild-type CARD11 induced NF-κB activation, which was further augmented by E626K mutation. Similarly, when both CARD11 (E626K) and PRKCB (D427N) mutants were co-expressed, more enhanced NF-κB activation was observed. RNA-seq and follow-up RT-PCR screening also identified novel gene fusions in TCR / NF-κB pathway: five CTLA4-CD28 and three ICOS-CD28 fusions were observed in seven (7%) of the 105 cases examined, of whom one patient carried both chimeric fusions. WGS revealed tandem duplications of 2q33.2 segments containing CD28, CTLA4, and ICOS, compatible with the corresponding fusion transcripts. B7/CD28 co-signaling molecules, including CD28, CTLA4, and ICOS co-receptors, play pivotal roles in positive and negative regulations of TCR signaling. All the predicted chimeric proteins had the cytoplasmic part of CD28, and are expected to be expressed under the control of the regulatory element of CTLA4 or ICOS, likely leading to prolonged expression of CD28 co-stimulator. Our findings suggest that deregulated TCR / NF-κB pathway caused by genetic alterations is a hallmark of ATL pathogenesis. The predominance of gain-of-function mutations in this pathway offers good opportunities for exploiting these mutations for the targets of novel drugs to better manage patients. Disclosures Tobinai: Gilead Sciences: Research Funding. Miyazaki:Sumitomo Dainippon: Honoraria; Celgene Japan: Honoraria; Chugai: Honoraria, Research Funding; Shin-bio: Honoraria; Kyowa-Kirin: Honoraria, Research Funding. Watanabe:Daiichi Sankyo Co., Ltd.: Research Funding.

Background: E7777 is a recombinant cytotoxic fusion protein composed of diphtheria toxin fragments A, B and human interleukin-2. E7777 has the same amino acid sequence as denileukin diftitox, approved in the USA for treatment of persistent or recurrent CD25 positive cutaneous T-cell lymphoma on 1999, but with improved purity and an increased percentage of active protein monomer species. Since the specific bioactivity of E7777 is 1.5-2 times higher than that of the prior less purified form, a phase 1 study of E7777 in Japanese patients (pts) with peripheral and cutaneous T-cell lymphoma (PTCL and CTCL) was conducted. Methods: This multicenter, phase 1, dose-escalation (3+3 design) study assessed the safety, maximum tolerated dose (MTD), recommended dose (RD), pharmacokinetics (PK), immunogenicity (IM) and anti-tumor activity in pts with relapsed or refractory PTCL and CTCL. E7777 was administered by IV infusion over 60 min on 5 consecutive days of every 21 day cycle (up to 8 cycles) at planned dose-levels of 6, 12, 15 and 18 μg/kg/day (with evaluation of intermediate dose levels if necessary). Premedication including systemic steroid was required. Dose-limiting toxicity (DLT) was evaluated during the first cycle and MTD was determined as the highest dose at which less than 2 of a total 6 pts experienced a DLT. In the event that 2 of 6 pts experienced DLTs in a dose level, an Independent Safety Committee (ISC) will be consulted on whether that dose can be considered the MTD. Anti-tumor activity was evaluated by IWG-2007 criteria (only CT assessment) for PTCL and mSWAT for CTCL. Tumor CD25 expression was examined by immunohistochemistry in pts with available archival samples. Results: A total of 13 pts were enrolled at E7777 dose-levels of 6, 9 and 12 μg/kg/day. 10 pts had PTCL [PTCL-not otherwise specified (NOS), n=4; angioimmunoblastic T-cell lymphoma (AITL), n=3; anaplastic large cell lymphoma (ALCL)-ALK positive, n=1; ALCL-ALK negative, n=1; enteropathy-associated T-cell lymphoma, n=1] and 3 had CTCL [mycosis fungoides (MF), n=3]. The median age was 64 years (range 23-75), and the median number of prior chemotherapy regimens (excluding PUVA, interferon, retinoid) was 1 (range 0-8). DLTs were observed in 3 of 3 pts in the 12 μg/kg/day cohort; ALT increased, hyponatremia, hypokalemia and lymphopenia in one pt, ALT increased, fatigue, hypoalbminemia, hyponatremia and rash in another, and lipase increased in the third. This dose-level was considered to exceed the MTD and the 9 μg/kg/day dose level was expanded. Per recommendation of the ISC, the DLT definition was modified to not include lymphopenia, Grade 3 abnormality of hepatic enzyme recovered to Grade 2 or lower within cycle 1, and any other Grade 3 clinical abnormal laboratory result without clinical symptoms recovered within 7 days. Two of 6 pts in 9 μg/kg/day cohort experienced DLT of decreased appetite and fatigue, respectively. These events were recovered from within 2-3 weeks while interrupting the treatment. Per protocol, the ISC evaluated the toxicity profile of all the pts, and recommended the MTD and RD to be 9 μg/kg/day. As of 10 May 2015, the common adverse events (AEs) were ALT increased (85%), AST increased (77%), decreased appetite (77%), fatigue (77%), lymphopenia (77%), hypoalbuminemia (69%) and nausea (62%). Serious AEs considered related to study drug were reported in 3 pts; ALT increased, AST increased and fatigue in one pt, decreased appetite and hypoxia in another, and delirium in the third. AEs leading to study discontinuation were reported in 3 pts; AEs were hypersensitivity, respiratory failure (not related) and delirium. Objective response rate as assessed by investigator was 38% (5/13 pts), including response in 4 of 10 pts with PTCL and 1 of 3 pts with CTCL. All responses were PRs including 2 pts (AITL) at 6 μg/kg/day, 1 pt (MF) at 12 μg/kg/day followed by 6 μg/kg/day from 2nd cycle, and 2 pts (PTCL-NOS) at 9 μg/kg/day. Tumor responses were observed regardless of the level of CD25 expression in tumors. PK and IM data will be presented. Conclusions: The MTD and RD of E7777 was 9 μg/kg/day. The common AEs observed were considered manageable. Tumor responses were observed in PTCL, which firstly demonstrated with E7777, and also for CTCL pts regardless of level of tumor CD25 expression. Subsequent phase 2 study to evaluate the efficacy and safety of E7777 in pts with PTCL and CTCL, including evaluation of the relationship with CD25 expression, is warranted. Disclosures Maruyama: Takeda Pharmaceutical Company Limited: Honoraria; Eisai Co., Ltd.: Honoraria. Tobinai:Gilead Sciences: Research Funding. Ando:Eisai Co., Ltd.: Honoraria, Research Funding. Ogura:Kyowa Hakko Kirin co., Ltd.: Research Funding; Eisai Co., Ltd.: Research Funding; Zenyaku Kogyo Co., Ltd.: Research Funding; Chugai Pharmaceutical Co., Ltd.: Research Funding; Phizer Japan Inc.: Research Funding; Janssen Pharmaceutical K.K.: Research Funding; GlaxoSmithKline K.K.: Research Funding; MSD K.K.: Research Funding; AstraZeneca K.K.: Research Funding; Takeda Pharmaceutical Company Limited: Research Funding; Symbio Pharmaceuticals Limited: Research Funding; Solasia Phama K.K.: Research Funding; Mundipharma K.K.: Research Funding; Celgene K.K.: Research Funding; Sumitomo Dainippon Pharma Co., Ltd.: Research Funding. Uchida:Eisai Co., Ltd.: Research Funding. Nakanishi:Eisai Co., Ltd.: Employment. Namiki:Eisai Co., Ltd.: Employment.

Background: Increased phosphatidylinositol-3-kinase delta (PI3Kd) activity drives proliferation and survival of malignant B-cells and mediates trafficking to lymphoid tissues. Idelalisib, a first-in-class, selective, oral inhibitor of PI3Kd, is approved in combination with rituximab for patients with relapsed CLL and as monotherapy in patients with relapsed/refractory (R/R) follicular lymphoma (FL) in North America and the EU. Methods: Six Japanese patients were enrolled between October 2014 and November 2014. This is an open-label 6+6 study design for continuous dosing of idelalisib 150mg BID in patients with R/R CLL and iNHL until PD or intolerable toxicity. The primary objective was to evaluate the 28-day safety, tolerability and pharmacokinetics of idelalisib and its metabolite GS-563117. The primary endpoint was the incidence of dose-limiting toxicity (DLT) defined as grade 4 hematological toxicities persisting for >14 days, grade ≥3 non-hematological toxicities, grade >3 laboratory abnormalities, red cell transfusion, and a therapeutic platelet transfusion. Key inclusion criteria were: age ≥20 yrs, patient of Japanese ancestry. Key exclusion criteria were known histological transformation to an aggressive histology, history of iNHL or CLL with CNS involvement. Response assessments as per modified Hallek 2008 and Cheson criteria 2007 were performed using CT scans at pre-determined time points by investigators. Results: Baseline characteristics included 3 patients each with CLL (2/3 refractory, 1/3 relapsed) or FL (3/3 refractory), and median age was 64 years (range 49-74). Median number of prior Rx regimens was 3.5 (range 1-6). Prior therapies included bendamustine plus rituximab (67%), R-CHOP (67%), and R-CVP (33%). No Japanese patients experienced a DLT within the 28-day window. The PK of idelalisib and GS-563117 were comparable between Japanese and non-Japanese patients; non-Japanese PK data predicted from preceding Phase 2 and Phase 3 studies. The most common treatment-emergent any grade/≥ grade 3 AEs in increasing frequency were gastritis (33%/0%), pyrexia (33%/0%), transaminases increased (33%/33%), chest pain (17%/0%), decreased appetite (17%/17%), diarrhea (17%/17%), neutrophil count decreased (17%/17%) and common laboratory abnormalities were decreased WBC (50%/17%), decreased neutrophil count (50%/17%), increased ALT (33%/17%), and increased AST (17%/17%). At the time of this analysis, a total of 3 patients experienced serious AEs (50%); decreased appetite, diarrhea, and increased transaminases. Investigator response assessments were 5/6 (83%) patients achieving partial response (PR) and 1/6 (17%) stable disease. Conclusions: Continuous dosing of idelalisib demonstrated a manageable safety profile with promising efficacy in Japanese patients with R/R CLL and FL. The PK of idelalisib and GS-563117 were comparable between Japanese and non-Japanese patients. The study was registered at ClincalTrials.gov (NCT02242045). Disclosures Kinoshita: Gilead Sciences: Research Funding. Fukuhara:Gilead Sciences: Research Funding. Nagai:Gilead Sciences: Research Funding. Izutsu:Gilead Sciences: Research Funding. Kobayashi:Gilead Sciences: Research Funding. Higuchi:Gilead Sciences: Research Funding. Harigae:Gilead Sciences: Research Funding. Tokunaga:Gilead Sciences: Research Funding. Adewoye:Gilead Sciences: Employment, Equity Ownership. Robeson:Gilead Sciences: Employment, Equity Ownership. Sharma:Gilead Sciences: Employment, Equity Ownership. Fukui:Gilead Sciences: Research Funding. Gao:Gilead Sciences: Employment, Equity Ownership. Christenson:Gilead Sciences: Employment, Equity Ownership. Tobinai:Gilead Sciences: Research Funding.

Background: Darinaparsin is a novel organic arsenic compound composed of dimethylated arsenic linked to glutathione, and has similar structure to one of the intermediates of the arsenic detoxification pathway. The mechanism of action includes induction of apoptosis in tumor cells, primarily through disruption of mitochondrial functions and increase in reactive oxygen species production. Two phase I studies of darinaparsin for injection were conducted in patients with relapsed or refractory (r/r) PTCL to evaluate its safety, efficacy and pharmacokinetics in Japan and Korea, respectively. Methods: Patients with histologically confirmed PTCL not otherwise specified (PTCL-NOS), angioimmunoblastic T-cell lymphoma (AITL), anaplastic lymphoma kinase (ALK) -positive anaplastic large cell lymphoma (ALCL) or ALK-negative ALCL who failed or were refractory to 1 or more prior systemic therapy were eligible. Darinaparsin was administered for 5 consecutive days at 200 mg/m2/day or 300 mg/m2/day every 4 weeks, or at 300 mg/m2/day every 3 weeks in the Japanese phase I study, and at 300 mg/m2/day every 4 weeks or every 3 weeks in the Korean phase I study. Darinaparsin was given intravenously over 1 hour, and the treatment was continued until disease progression or unacceptable toxicity. As one of the secondary endpoints, tumor response was explanatorily assessed by using the Revised Response Criteria for Malignant Lymphoma (Cheson BD et al, J Clin Oncol 2007) in patients who completed at least 2 cycles of treatment and who had evaluable data of FDG-PET and CT scan. Since use of an inorganic arsenic compound is limited by cardiotoxicity, the potential of darinaparsin to prolong QTcF and any possible relationship between darinaparsin plasma concentration and change in QTcF were assessed. Results: In these 2 studies, 17 Japanese patients and 6 Korean patients; a total of 23 patients, included 16 PTCL-NOS, 6 AITL and 1 ALK-negative ALCL; 14 males and 9 females, with a median age of 63 (range 22-83) years were enrolled. Dose-limiting toxicities occurred in 1 Japanese patient who received 300 mg/m2/day (grade [G] 3 hepatic dysfunction). Drug-related adverse events >= G3 were reported in 4 Japanese patients who received 300 mg/m2/day. Occurrence of diffuse large B-cell lymphoma was reported in 1 patient, anemia in 1, leukopenia in 1, neutropenia in 2, febrile neutropenia in 1, lymphopenia in 2, thrombocytopenia in 2, hepatic dysfunction in 1, nausea in 1 and activated partial thromboplastin time (APTT) prolonged in 1. No drug-related adverse event >= G3 was reported in Korean patients. No patient showed QTcF >500 msec or delta QTcF >60 msec throughout the study period. Concentration-dependent or treatment-duration-independent effect on the QTcF was not identified. There was no significant relationship between the plasma concentration of darinaparsin and a change in QTcF interval (r=0.003). Tumor response was assessed in 14 patients who completed at least 2 cycles of treatment, and objective response was observed in 4 patients (1 complete response and 3 partial responses). Five of 6 patients with stable disease showed tumor shrinkage to some extent. In Japanese and Korean patients who received 300 mg/m2/day, the mean (± SD) values of Cmax were 838 ± 181 and 708 ± 81 ng/mL, AUC0-24 were 12759 ± 3419 and 11282 ± 905 ng•h/mL, and t1/2 were 20 ± 6.3 and 20.6 ± 2.8 h, respectively. The systemic arsenic exposures were similar between Japanese and Korean patients. There was no apparent difference in the mean plasma concentration-time profiles between Japanese and Korean patients at the doses studied. Conclusion: The results from integrated data analysis of these 2 phase I studies revealed that darinaparsin was well tolerated at all doses and dosing schedules studied, and demonstrated its potential efficacy against r/r PTCL. Furthermore, it was suggested that 300 mg/m2/day for 5-consecutive days every 3 weeks would be the recommendable dosing schedule of darinaparsin for subsequent studies. Based on the promising results of these phase I studies, we are planning to conduct an Asian multicenter phase II study for r/r PTCL. Disclosures Kim: Kyowa-Kirin: Research Funding; Takeda: Research Funding; Novartis: Research Funding; Roche: Research Funding; Donga: Research Funding; Merck: Research Funding. Ogura:Eisai Co., Ltd.: Research Funding; Kyowa Hakko Kirin co., Ltd.: Research Funding; Zenyaku Kogyo Co., Ltd.: Research Funding; Chugai Pharmaceutical Co., Ltd.: Research Funding; Phizer Japan Inc.: Research Funding; Janssen Pharmaceutical K.K.: Research Funding; GlaxoSmithKline K.K.: Research Funding; MSD K.K.: Research Funding; AstraZeneca K.K.: Research Funding; Takeda Pharmaceutical Company Limited: Research Funding; Symbio Pharmaceuticals Limited: Research Funding; Solasia Phama K.K.: Research Funding; Mundipharma K.K.: Research Funding; Celgene K.K.: Research Funding; Sumitomo Dainippon Pharma Co., Ltd.: Research Funding. Uchida:Eisai Co., Ltd.: Research Funding. Ishizawa:Takeda: Speakers Bureau; Janssen: Research Funding; Takeda: Research Funding; Kyowa Kirin: Speakers Bureau; GSK: Research Funding; Kyowa Kirin: Research Funding; Celgin: Research Funding; Pfizer: Speakers Bureau; Celgin: Speakers Bureau. Tobinai:Gilead Sciences: Research Funding. Nagahama:Solasia Pharma K.K.: Employment. Sonehara:Solasia Pharma K.K.: Employment. Nagai:Servier: Research Funding; Mundipharma: Research Funding; Otsuka: Research Funding; Takeda: Research Funding; CMIC: Research Funding; Janssen: Research Funding; Gilead Sciences: Research Funding.

Introduction: Pomalidomide plus low-dose dexamethasone (POM + LoDEX) is approved for the treatment of patients with relapsed and refractory multiple myeloma (RRMM). In RRMM, POM + LoDEX significantly prolonged progression-free survival (PFS) compared with POM alone (MM-002; Richardson et al Blood, 2014) and significantly improved PFS and overall survival (OS) compared with high-dose DEX alone (MM-003; San Miguel et al Lancet Oncol, 2013), while demonstrating an acceptable safety profile. In Japanese patients with RRMM, a phase 1 study identified POM 4 mg/day as the tolerated dose (MM-004; Iida ASH 2014), consistent with observations in Caucasian patients. The study presented here, MM-011, was conducted to evaluate the efficacy and safety of POM + LoDEX in Japanese patients with RRMM. Methods: MM-011 was a multicenter, single-arm, open-label phase 2 study in patients with RRMM. Eligible patients had received ≥ 2 prior therapies, including ≥ 2 cycles of lenalidomide and ≥ 2 cycles of bortezomib (either separately or in combination) and had developed progressive disease on or within 60 days of the last prior therapy. Patients received POM 4 mg orally on days 1-21, and LoDEX orally on days 1, 8, 15, and 22 of each 28-day cycle. LoDEX was given at 40 or 20 mg in patients aged ≤ 75 or > 75 years, respectively. Treatment was continued until disease progression, unacceptable toxicity, or withdrawal of consent. The primary endpoint was overall response rate (ORR; partial response rate [PR] or better) of POM + LoDEX according to the International Myeloma Working Group criteria. The required sample size was calculated using the expected response rate of 25%, the threshold response rate of 10% on 1-sided alpha of 0.05, and the statistical power of 80% based on the test for 1 sample proportion. Thirty-three pts were needed as a result of this calculation. Results: A total of 36 patients were enrolled. Median age was 64.5 years (range, 43-78 years), and 11% were aged > 75 years. Patients had a high tumor burden (81% had Durie-Salmon stage II or III disease) and were heavily pretreated (median of 6.5 prior anti-myeloma regimens; range, 2-15 regimens). All but 1 patient (97%) were refractory to lenalidomide and 58% were refractory to both lenalidomide and bortezomib. At the data cutoff (February 3, 2015), 16 patients (44%) remained on treatment. Disease progression was the most common reason for discontinuation (n = 14; 39%). All 36 patients enrolled were evaluable for efficacy. The ORR was 42% (n = 15 [95% CI, 26%-58%]), including complete response in 3% (n = 1) and PR in 39% (n = 14). Median PFS was 10.2 months (median follow-up, 4.6 months), and median OS was not reached (median follow-up, 7.7 months). In the 15 responders, median time to response was 1.9 months and median duration of response was not reached. The most common grade 3/4 hematologic adverse events (AEs) were neutropenia (n = 23; 64%), anemia (n = 15; 42%), and thrombocytopenia (n = 11; 31%), and the most common grade 3/4 non-hematologic AEs were pneumonia (n = 3; 8%) and decreased appetite (n = 3; 8%). Peripheral neuropathy (any grade) occurred in 8% (n = 3). No deep vein thrombosis or pulmonary embolism was reported. Overall, AEs were similar to those in other POM studies, and no new significant AEs were reported in Japanese RRMM patients. Three patients (8%) had an AE that led to discontinuation. Three patients died on study (or within 28 days of the last dose of study drug). Two of these patients died due to multiple myeloma and 1 due to AE (asthma and pneumonia, suspected to be related to study drug). Conclusions: POM + LoDEX is an effective regimen in heavily pretreated Japanese patients with RRMM with acceptable safety profiles that are comparable with those of POM studies in RRMM in other regions. Disclosures Hagiwara: Celgene Corporation: Membership on an entity's Board of Directors or advisory committees. Matsue:Celgene Corporation: Honoraria. Iida:Celgene Corporation: Honoraria, Research Funding; Janssen Pharmaceuticals Inc: Honoraria; Kyowa Hakko Kirin Inc: Research Funding; Ono Pharmaceutical Inc: Research Funding; Chugai Pharmaceutical Co: Research Funding; Eli Lilly Inc: Research Funding. Sunami:Ono Pharmaceutical Company, Limited: Research Funding; Takeda Pharmaceutical Company Limited: Research Funding. Ando:Kyowa Hakko Kirin Co., Ltd: Research Funding. Tobinai:Gilead Sciences: Research Funding. Chou:Celgene Corporation: Consultancy, Honoraria; Janssen: Consultancy, Honoraria; Novartis: Consultancy, Honoraria; Ono Pharmaceutical CO., LTD.: Consultancy, Honoraria. Kaneko:Celgene Corporation: Research Funding. Uemura:Celgene Corporation: Employment. Tamakoshi:Celgene Corporation: Employment. Zaki:Celgene Corporation: Employment, Equity Ownership. Doerr:Celgene Corporation: Employment.

Introduction The watch and wait (WW) strategy has been regarded as one of the standard approaches in patients with asymptomatic follicular lymphoma (FL) regardless of their tumor burden. However, the impacts of initial WW on treatment efficacy, outcomes and histologic transformation in FL patients in the rituximab era remain elusive. Patients and methods We retrospectively analyzed 348 consecutive patients who were initially diagnosed as having FL of grade 1 to 3a at our institution between 2000 and 2012. We analyzed time to treatment failure (TTF), and compared patients who underwent treatment following WW with those who immediately received treatment without WW. Both overall survival (OS) and time to transformation in the WW cohort and the immediate treatment cohort were also analyzed. In this particular study, TTF was defined as the time from diagnosis until progression after the initiation of first treatment. Results In all 348 patients with a median age of 57 years (range: 19-85), 101 patients were initially managed with WW and 247 were immediately treated at the physician's discretion. The proportions of patients with low tumor burden according to the GELF criteria were 80% (81 patients) in the WW cohort and 47% (117 patients) in the immediate treatment cohort. The median follow-up duration of all 348 patients was 75 months (range: 7-169). In the WW cohort, 45 patients (45%) received anti-lymphoma treatment, mainly because of FL progression, after a median WW duration of 16 months (range: 3-122). The majority of patients (84% in the treatment following WW group, 77% in the immediate treatment group) received a rituximab-containing regimen. The estimated median TTF in the treatment following WW cohort and the immediate treatment cohort were 92 months (95%CI, 60.1-NA) and 85 months (95%CI, 66.3-113), respectively, which were not significantly different (P=0.336) (Figure 1). In multivariate analysis, clinical stage was the predictive factor of TTF (HR 1.18, 95% CI, 1.02-1.38, P 60years (HR 3.87, 95% CI, 1.52-9.85, P Conclusion The results of our analysis suggested that the WW strategy does not have negative impacts on TTF, OS and histologic transformation in selected patients with FL regardless of tumor burden, indicating that this strategy can still be regarded as an acceptable approach to FL patients in the rituximab era. Further investigations, especially a prospective cohort study including evaluation of the optimal timing for starting anti-lymphoma treatment following WW, are needed to confirm our results. Figure 1 Figure 1. Figure 2 Figure 2. Disclosures Maruyama: Eisai Co., Ltd: Honoraria. Kobayashi:Behringer Ingelheim GmbH: Research Funding; Ohtsuka Pharmaceutical Co., Ltd: Research Funding; ARIAD Pharmaceutical Co., Ltd: Research Funding. Tobinai:Chugai Pharmaceutical: Research Funding; Zenyaku Kogyo: Research Funding.

Introduction: Although bendamustine with or without rituximab has demonstrated remarkable efficacy in patients with relapsed or refractory indolent B-cell lymphoma (B-NHL) and mantle cell lymphoma (MCL), previous reports showed that the incidence of lymphocytopenia was higher in patients receiving bendamustine with or without rituximab than in those receiving other conventional cytotoxic chemotherapies such as R-CHOP regimen. However, the length of time until recovery of the decreased lymphocytes and CD4-positive T cells to the baseline upon bendamustine treatment is still unclear. Patients and Methods: We retrospectively analyzed 56 consecutive patients with relapsed or refractory B-NHL and MCL who received bendamustine with or without rituximab at our institution between 2011 and 2014. We analyzed their peripheral blood lymphocytes and CD4-positive T-cell counts at baseline, during, and after bendamustine treatment, the details of infectious events, and their correlations. Results: Thirty-one (55%) patients were male and 25 (45%) female, with a median age of 63 years (range: 36-86). Twenty (35%) patients had follicular lymphoma, 14 (25%) MCL, nine (16%) transformed lymphoma, five (9%) extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue, four (7%) small lymphocytic lymphoma, two (4%) nodal marginal zone lymphoma, and one (2%) each had lymphoplasmacytic lymphoma and low-grade B-NHL, unclassifiable. The median number of prior regimens administered was two (range: 1-9). Twenty-three (41%) of the 56 patients received rituximab in combination with bendamustine. The median number of bendamustine cycles was four (range: 1-6). The median follow-up period was nine months (range: 0-33 months). At baseline, median lymphocyte and CD4-positive T-cell counts were 1,025/µL (range: 270-3,420/µL) and 282/µL (range: 83-645/µL), respectively. After the first cycle, they immediately decreased to 545/µL (range: 60-2,900/µL) and 190/µL (range: 116-635/µL), respectively. The median lymphocyte and CD4-positive T-cell count nadirs during observation were 365/µL (range: 20-1,310/µL) and 93/µL (range: 7-178/µL), respectively. Significantly decreased lymphocyte counts (median: 260 vs. 410/µL) were detected in the patients who received bendamustine with rituximab compared with those who received bendamustine alone (p=0.03). Recovery of lymphocyte and CD4-positive T-cell counts to those at baseline was observed at 7-9 months after the completion of bendamustine with or without rituximab, and median lymphocyte and CD4-positive T-cell counts were 1,045/µL (range: 170-2,580/µL) and 223/µL (range: 47-709/µL), respectively (Figures A, B). The numbers of patients who received prophylaxis against pneumocystis pneumonia (PCP), varicella zoster virus (VZV), and fungal infection were 44 (78%), 37 (66%), and four (7%), respectively, at the physician's discretion. Infectious events were observed in 32 (57%) patients during follow-up. Cytomegalovirus antigenemia was detected in 15 (27%) patients, VZV infection in two (3%), cytomegalovirus colitis in one (2%), and other infectious complications such as sepsis or febrile neutropenia in 20 (35%) patients. Interestingly, all infectious events occurred within nine months after the completion of bendamustine with or without rituximab in patients who received no treatment after bendamustine during follow-up. Conclusion: The results of this analysis revealed that the majority of relapsed or refractory patients with indolent B-NHL and MCL showed prolonged lymphocytopenia and low CD4-positive T-cell counts, for at least 7-9 months, after the completion of bendamustine with or without rituximab. Because lymphocytopenia, especially low CD4-positive T-cell counts, may increase the risk of opportunistic infections, the prophylaxis against PCP and VZV deserves consideration for at least 7-9 months after bendamustine treatment. Further investigations, especially a prospective study, are needed to confirm our results. Figure A: Figure A:. Figure B: Figure B:. Box plots of lymphocyte counts (Figure A) and CD4-positive T-cell counts (Figure B) among patients who were treated with bendamustine with or without rituximab. Disclosures Maruyama: Eisai Co., Ltd: Honoraria. Kobayashi:Boehringer Ingelheim GmbH: Research Funding; ARIAD Pharmaceuticals, Inc.: Research Funding; Otsuka Pharmaceutical Co., Ltd.: Research Funding. Tobinai:Eisai Co., Ltd.: Research Funding; SymBio Pharmaceuticals Ltd.: Research Funding; Chugai Pharmaceutical Co., Ltd.: Research Funding; Zenyaku Kogyo Co., Ltd.: Research Funding.

Introduction Although the Japanese multicenter phase II trial in localized primary gastric diffuse large B-cell lymphoma (PG-DLBCL), which evaluated three cycles of CHOP followed by radiotherapy (RT), showed good prognosis (Cancer Sci 2005; 96: 349), reports about outcomes and prognostic factors of localized PG-DLBCL patients in the rituximab era are limited. Recently, it has been reported that the concurrent expression of MYC and BCL2 predicts unfavorable outcome in DLBCL patients treated with R-CHOP (J Clin Oncol 2012; 30: 3460). However, the impact of the concurrent expression of MYC and BCL2 on outcomes of localized PG-DLBCL patients has never been reported. Patients and Methods We retrospectively analyzed 52 consecutive patients diagnosed as having localized (stage I or II according to the Lugano Staging System for Gastrointestinal Lymphomas) PG-DLBCL who were initially treated at our institution between 2003 and 2013. Positivity of MYC in immunohistochemistry was defined as labeling of tumor cells of more than 40% and positivity of BCL2 was defined as more than 70%. The lymphoma cells were assigned a GCB or non-GCB phenotype using the Hans algorithm for determining the cell-of-origin (COO) subtyping. Results Twenty-four (46%) patients were male and 28 (54%) female, with a median age of 62 years (range: 29-85). Thirty (58%) patients presented with stage I disease, 15 (29%) with stage II1, two (4%) with stage II2 and five (9%) patients with stage IIE. Most patients (47 patients; 90%) had low or low-intermediate risk based on the International Prognostic Index. Fifty (96%) patients received R-CHOP with or without RT, and one each received CHOP plus RT, and total gastrectomy followed by rituximab. The median number of CHOP cycles was three (range: 2-8). The majority (43 patients; 83%) of patients were treated with R-CHOP followed by RT. COO subtype could be determined in 48 of the 52 patients (63% GCB and 37% non-GCB). Both MYC and BCL2 expression could be assessed in 47 of the 52 patients, and the concurrent expression of MYC and BCL2 was confirmed in seven (15%) patients. In this analysis, no patients showed positivity for EBER-1 in situ hybridization, which was reported as an adverse prognostic factor of localized PG-DLBCL in the pre-rituximab era. Median follow-up duration was 76 months (range: 4-127 months). Fifty (96%) patients achieved complete responses, and the remaining two without concurrent expression of MYC and BCL2 had primary refractory disease. The estimated 5-year overall and progression-free survival rates of all 52 patients were 90% (95% CI, 75-96%) and 89% (95% CI, 75-95%), respectively (Fig. 1). The estimated 5-year overall survival rates of GCB phenotype and non-GCB phenotype cases were 86% (95% CI, 63-96%) and 93% (95% CI, 59-99%), respectively, with no statistically significant difference (p=0.96). The estimated 5-year overall survival rates of the patients with and without concurrent expression of MYC and BCL2 were 100% and 88% (95% CI, 72-96%), respectively (Fig. 2). There was no significant difference between the two cohorts (p=0.74). Conclusions The results of our analysis showed good prognosis, and revealed that COO subtype and concurrent expression of MYC and BCL2 did not influence the outcome in patients with localized PG-DLBCL treated with rituximab-containing chemotherapy with or without RT. Further investigations, especially a prospective cohort study, are needed to confirm our results. Figure 1 Figure 1. Figure 2 Figure 2. Disclosures Maruyama: Eisai Co., Ltd: Honoraria. Kobayashi:Otsuka Pharmaceutical Co., Ltd.: Research Funding; ARIAD Pharmaceuticals, Inc.: Research Funding; Boehringer Ingelheim GmbH: Research Funding. Tobinai:Zenyaku Kogyo: Research Funding; Chugai Pharmaceutical: Research Funding.

Introduction Multiple myeloma (MM) is an incurable plasma cell neoplasm developing through long-term multistep genetic events. Biological and clinical features of the MM are known to be associated in part with relatively early genetic aberrations such as chromosomal translocations involving IGH. The t(14;16)(q32;q23) involving c-MAF oncogene locus is an important chromosomal aberration observed in approximately 5 percent of newly diagnosed MM. Various studies have suggested that MM carrying t(14;16) is associated with specific clinical characteristics. However, these studies were not definitive, since the number of the patients analyzed was relatively small. The aim of this study is to clarify the clinical features of patients with newly diagnosed MM harboring t(14;16) detected by double-color fluorescence in situ hybridization (FISH) in Japan. Methods Clinical and laboratory features of t(14;16)-positive MM diagnosed between 2002 and 2013 were collected retrospectively as a nationwide study in Japan after approval by each institutional ethical committee. The t(14;16) translocation was detected by FISH analysis using bone marrow or peripheral blood samples from all patients. Expression of surface antigens such as CD56 and CD20 was detected by flow cytometric analysis (FCM) and defined as positive when more than 20% of the CD38-positive plasma cells were positive. To compare t(14;16)-positive and t(14;16)-negative MM, we also assessed 132 patients with newly diagnosed symptomatic MM and without c-MAF mRNA expression, as confirmed by global RQ/RT-PCR using purified plasma cells (Tajima E, et al.:Haematologica 2005; 90: 559, Inagaki A et al.: Leuk Res 2013; 37: 1648) at Nagoya City University Hospital. Results In total, 37 patients carrying t(14;16)-positive MM were enrolled from 19 institutions. Median ages of the MM patients with or without t(14;16) at diagnosis were 62 and 68, respectively. Regarding the cell surface phenotype, none of the t(14;16)-positive MM cells was positive for CD56 (Fig. 1), whereas 82 of 118 (69%) t(14;16)-negative ones were positive. Positivity for CD20 antigen was more common in t(14;16)-positive MM cells (11/23, 48%) than in t(14;16)-negative ones (16/115, 14%)(p= 0.001). The proportion of patients with additional chromosome aberrations other than t(14;16), determined by G-banded karyotyping, was higher in patients with t(14;16) (16/30, 53%) than in those without (19/131 cases, 15%) (p< 0.001). Moreover, MM patients with t(14;16) showed higher frequencies of IgG subtype M protein, leukocytosis (p= 0.001), thrombocytopenia (p< 0.001) and hyperproteinemia (p= 0.001), and a lower frequency of hypercalcemia (p= 0.001), compared to those without t(14;16). Overall survival (OS) of the patients with t(14;16) was significantly shorter than that of those without t(14;16) even though the patients received one or more lines of treatment containing novel drugs such as bortezomib, thalidomide and lenalidomide (p= 0.014) (Fig. 2). Poor PS (PS ≥ 2-4), low PLT count (1.0N) were significantly unfavorable prognostic factors for OS in patients with t(14;16)-positive MM, whereas they were not in those without t(14;16). Progression-free survival (PFS) of the patients with t(14;16) was also significantly shorter than those without t(14;16) (p= 0.002) Conclusion The t(14;16)-positive MM comprises a specific category in MM, which is featured by negativity for CD56, higher positivity for CD20 and unfavorable outcome, even in the novel drug era. Unraveling biological characteristics of this specific disease category will lead us to establish novel treatment strategies. Disclosures No relevant conflicts of interest to declare.

Background Despite improvements in outcome following the addition of rituximab (R) to CHOP (cyclophosphamide, doxorubicin, vincristine, prednisone) (R-CHOP), patients with newly diagnosed diffuse large B-cell lymphoma (DLBCL) and International Prognostic Index (IPI) scores of 3-5 at diagnosis have a poor outcome. Enzastaurin is a potent inhibitor of PKCβ, a component of the B-cell receptor signaling complex, with preclinical activity and clinical activity in a phase II trial in patients with relapsed DLBCL, providing the rationale for this study in the primary therapy setting. Methods PRELUDE was a multi-national, randomized, double-blinded, placebo-controlled study. Patients were required to have a histologic diagnosis of DLBCL, pre-treatment IPI score ≥3, and a complete response (CR) or CRu by International Working Group Criteria, or a negative FDG-PET scan after 6–8 cycles of R-CHOP. Patients were randomly assigned in a 2:1 ratio to receive either enzastaurin 500 mg daily or an identical placebo as maintenance therapy, for a planned treatment duration of 3 years. The primary endpoint was DFS, defined as lack of disease progression or death. Assuming a 2-year DFS rate in the control group of 70%, the primary analysis had 80% power to detect a HR of 0.67, eg, a 2-year DFS rate of 79% in the enzastaurin group. Secondary endpoints included overall survival (OS) and event-free survival (EFS). Data were analyzed 3 years after the last enrolled patient initiated treatment. Results From May 2006–April 2010, 758 patients were enrolled (enzastaurin, n=504; placebo, n=254). Median age at enrollment was 64 years (range 21-89); at diagnosis, 65% of patients had stage IV disease, 48% had B symptoms, and 25% had a mass >10 cm; baseline disease and patient characteristics were well balanced between treatment arms. Fifty-seven percent had a negative PET scan following completion of R-CHOP. Median follow-up time for all patients was 48 months (range 0.03–80). At the time of analysis, 209 events had occurred. The DFS HR for enzastaurin vs. placebo was 0.92 (95% CI: 0.69, 1.22; 2-sided log-rank p=0.54). DFS at 24 and 48 months were 79% and 70% for the enzastaurin arm, and 75% and 71% for placebo, respectively. OS at 24 and 48 months was 87% and 81% for enzastaurin, and 89% and 82% for placebo; HR for enzastaurin vs. placebo was 1.04 (95% CI: 0.74, 1.47; 2-sided log-rank p=0.81). Percent of ITT population patients on therapy at 12, 24, and 36 months was 70.6%, 60.6%, and 20.1% for enzastaurin; 72.3%, 60.6%, and 22.1% for placebo. Biomarker subgroup analysis was performed and will be available at time of presentation. Treatment emergent AEs (all grades) that were possibly study drug-related and significantly different between enzastaurin and placebo included chromaturia (18.5% vs. 0.4%), QTc prolongation (10.8% vs. 3.6%), and diarrhea (10.3% vs. 2.8%). There were no significant differences in number of patients with at least 1 grade 3 or higher AE between treatment arms. No significant differences were observed in the frequency of deaths while on therapy. Conclusion Enzastaurin did not improve DFS, EFS, or OS in patients with high-risk DLBCL and CR following R-CHOP treatment. Disclosures: Crump: Roche: Honoraria; Jansen-Ortho: Honoraria; Celgene: Honoraria; Lundbeck: Honoraria; Novartis: Research Funding; Seattle Genetics: Honoraria. Off Label Use: rituximab for maintenance therapy post autolgous transplant for lymphoma. Leppä:Eli Lilly: Research Funding. Ogura:Eli Lilly: Research Funding. Rifkin:Millenium, Celgene, ONYX: Membership on an entity’s Board of Directors or advisory committees. Mackensen:Eli Lilly: Consultancy. Offner:Eli Lilly: Membership on an entity’s Board of Directors or advisory committees. Smith:Genentech, Celgene, Spectrum, Seattle Genetics, Gilead, Amgen/Micronet: Consultancy. Tobinai:Eli Lilly: Research Funding. Hahka-Kemppinen:Eli Lilly: Employment. Thornton:Eli Lilly: Employment. Shi:Eli Lilly: Employment. Lin:Eli Lilly: Employment. Kahl:Genentech: Consultancy. Savage:Eli Lilly: Consultancy.

Background B-cell lymphoma, unclassifiable, with features intermediate between diffuse large B-cell lymphoma and Burkitt lymphoma (iBL/DLBCL) by WHO classification 2008 is a rare subtype. Some cases of iBL/DLBCL have both MYC and BCL2 translocations (double hit translocation, DHT) by fluorescent in situ hybridization (FISH) or G-band staining, and DHT is an indicator of poor prognosis. Recently, detection method of c-MYC protein was developed. The staining might be an emerging tool to detect DLBCL cases with poor prognosis. Using this staining, double hit score (DHS) is defined as a sum of the numbers, whose count is 1 (positive) or 0 (negative) according to the status of MYC and BCL2 immunoreactivity, and those patients in whom DHS is 2 (DHS 2) have been reported to have a poor prognosis in DLBCL. However, the incidence of DHT and the significance of DHS in iBL/DLBCL has not been adequately studied. Herein we evaluated these parameters as potential prognostic indicators of iBL/DLBCL. Patients and Methods We retrospectively analyzed the clinicopathological features of 24 patients with iBL/DLBCL between 2000 and 2011. MYC split and IGH/BCL2 fusion by FISH analysis and MYC and BCL2 immunostaining were performed. Immunoreactivity of MYC was judged to be positive when MYC protein was expressed in more than 40% of the lymphoma cells. Survival analyses were performed using the Kaplan-Meier curves and compared using the log-rank test. Results The median age of the 24 patients with iBL/DLBCL was 47 years (range:16-79 years). All patients had received systemic chemotherapy regimens such as CHOP (n=9) or CODOX-M/IVAC (n=15), with or without rituximab. The iBL/DLBCL patients 60 years or older had received CHOP +/- R, and those patients younger than 60 years had received CODOX-M/IVAC +/- R according to our institution’s policy. The 4-year progression-free survival (PFS) and overall survival (OS) rates were 63 and 72%, respectively. Twelve patients (50%) had stage IV disease, 14 (58%) had high serum LDH levels, and 16 (66%) had extranodal presentation. IPI was low in 9 patients, low-intermediate in 4, high-intermediate in 3, and high in 7. The incidence of MYC, BCL2 immunoreactivity, and both (DHS 2) was 81%, 29%, and 14%, respectively. Three patients were not evaluated for MYC immunoreactivity. The incidence of MYC split, IGH/BCL2 fusion, and DHT was 55%, 30%, and 17%, respectively. Two patients were not evaluated for MYC split and 4 patients were not evaluated for IGH/BCL2 fusion. More patients with MYC immunoreactivity were found than those with MYC split, and 4 patients (21%) had MYC immunoreactivity despite lack of MYC split, and only one patient (5%) had MYC split without MYC immunoreactivity. All patients with IGH/BCL2 fusion had BCL2 immunoreactivity. The incidence of patients with Ki67 index more than 90% was 88%. Univariate analysis revealed that PFS was significantly shorter in patients aged ≥60 years (P =.042) and in those with high IPI scores (P Conclusions Immunoreactivity of MYC was more frequently observed than MYC split and its positivity with combination of IGH/BCL2 fusion or immunoreactivity of BCL2 provides clinical significance, thus, serving as a useful tool. Disclosures: Kobayashi: Ariad, Behringer, Ohtsuka, Onconova, Novartis: Research Funding.

Latent membrane protein 1 (LMP1), cutaneous lymphocyte antigen (CLA), NK-cell origin, and pretreatment bone marrow Epstein-Barr virus - encoded RNA by in situ hybridization (EBER-ISH) have been reported as prognostic biomarkers in patients with extranodal NK/T-cell lymphoma (NKTCL), nasal type when treated with conventional therapy (Kanemitsu N, et al. Clin Cancer Res 2012; Yoshino T, et al. Br J Haematol 2002; Kim GE, et al. Head Neck 2004; Lee J, et al. Clin Cancer Res 2007). Recently, concurrent chemoradiotherapy has become a standard management approach for newly diagnosed, localized, nasal NKTCL (Yamaguchi M, et al. J Clin Oncol 2009; Kim SJ, et al. J Clin Oncol 2009). Because it is a new treatment modality for lymphoma, little data are available on the prognostic biomarkers of NKTCL among patients treated with concurrent chemoradiotherapy. To evaluate the prognostic significance of known immunophenotypic biomarkers among patients treated with concurrent chemoradiotherapy, we conducted an ancillary clinicopathologic study of JCOG0211, which was a phase I/II trial of concurrent chemoradiotherapy (RT-DeVIC) for newly diagnosed, localized, nasal NKTCL (Yamaguchi M, et al. J Clin Oncol 2009 & 2012). The histological diagnoses of all 33 patients who were enrolled in JCOG0211 were confirmed as extranodal NKTCL, nasal type, by the Central Pathology Review. Pathological samples from 32 patients were available for the study. Patients received concurrent chemoradiotherapy comprising RT of 50 Gy and 3 cycles of DeVIC. The expression of LMP1 and CLA in tumor cells was examined using immunohistochemistry with paraffin sections of pretreatment lymphoma samples. Two monoclonal antibodies for TCRβ (βF1) and TCRγ (CγM1) were used to evaluate the cell of origin of lymphoma cells. Preliminary examination revealed that βF1 and CγM1 specifically recognized αβ and γδ T cells, respectively. Cases were considered to be of NK-cell origin if both TCRβ and TCRγ were negative. Cases showing positive staining for one or both of the antibodies (TCRβ and TCRγ) were determined to be of T-cell origin. Pretreatment bone marrow specimens from patients were examined for EBER-ISH. LMP1 and CLA were positive in 66% (19/29) and 29% (9/31) of the cases, respectively. Among 32 cases examined for cell lineage, 27 (84%) cases were of NK-cell origin. Two (6%) cases were of αβ T-cell origin on the basis of positivity for TCRβ but not TCRγ, and 3 (9%) cases were of γδ T-cell origin on the basis of positivity for TCRγ but not TCRβ. Pretreatment bone marrow EBER-ISH was positive in 2 (7%) out of 29 cases examined. The median follow-up was 68 months (range, 61-94). The overall survival (OS) was better in the LMP1-positive (LMP1+) group than in the LMP1-negative (LMP1-) group [hazard ratio (HR), 0.240; 95% confidence interval (CI), 0.057-1.013; 80% CI, 0.093-0.615; P=0.035]. The OS at 5 years was 84% (95% CI, 59-95%) in the LMP1+ patients and 50% (95% CI, 18-75%) in the LMP1- patients. The progression-free survival (PFS) at 5 years was 74% (95% CI, 48-88%) in the LMP1+ patients and 50% (95% CI, 18-75%) in the LMP1- patients. The HR of PFS in the LMP1+ patients was 0.421 (95% CI, 0.121-1.463; 80% CI, 0.187-0.950). There were no significant differences in the OS and PFS between the CLA+ and CLA- patients (5-yr OS, 56% vs. 77%; 5-yr PFS, 56% vs. 68%). All 5 patients of T-cell origin achieved complete response by RT-DeVIC and were alive without relapse at the last follow-up. The OS and PFS at 5 years in the 27 patients of NK-cell origin were 67% (95% CI, 46-81%) and 59% (95% CI, 39-75%), respectively. Two patients who were positive for pretreatment bone marrow EBER-ISH survived more than 5 years without disease progression (5-yr OS and PFS, 100%). Our current study, for the first time, validated a favorable impact on the OS of LMP1 expression in newly diagnosed, localized, nasal NKTCL in a cohort uniformly treated with concurrent chemoradiotherapy. Further evaluation with a larger number of patients is warranted. (Supported in part by The National Cancer Center Research and Development Funds #21-6-3 & #23-A-17) Disclosures: Ishizuka: Sanofi: Employment. Oshimi:Eisai: Employment.

Abstract 3693 Background: Histopathologically, some FLs have components of DLBCL at diagnosis. In the pre-rituximab era, there were two reports regarding the characteristics and prognosis of patients (pts) with these particular FLs1,2). Hans et al. reported that the overall survival (OS) of pts with FL grade 3 having a predominant (> 50%) DLBCL component is similar to that of pts with DLBCL1). Ghesquières et al. concluded that pts with DLBCL presenting with a low-grade component have a similar OS to those with de novo DLBCL2). However, the clinical implications and prognosis of FL pts with coexisting DLBCL at diagnosis undergoing rituximab-containing chemotherapy remain unclear. Patients and Methods: We retrospectively analyzed the clinicopathologic features of 59 FL pts with coexisting DLBCL (FL/DLBCL) initially undergoing rituximab-containing chemotherapy. Furthermore, the prognosis of FL/DLBCL pts was compared with that of 223 FL pts without DLBCL as well as 285 DLBCL pts without FL3). All pts received a rituximab-containing regimen as the initial chemotherapy. These pts with FL/DLBCL or FL were diagnosed and treated at our institution between 2001 and 2010, and DLBCL pts between 2003 and 2010. Results: The median age of the 59 pts with FL/DLBCL was 54 years (range: 22–83). Among them, 41 (69%) pts had FL grade 1–3a and the remaining 18 (31%) had FL grade 3b components. Thirty (51%) pts had a predominant (> 50%) DLBCL component. With regard to treatment, all pts except one received the R-CHOP regimen. Forty-nine (83%) pts achieved CR, but 22 of them (37%) relapsed. With a median follow-up of 5.4 years, the estimated 5-year OS and progression-free survival (PFS) for all 59 pts were 83 and 64%, respectively. The International Prognostic Index (IPI) and FLIPI were not correlated with OS and PFS, whereas the revised-IPI (R-IPI) and FLIPI2 were significantly correlated with PFS. A predominant DLBCL component was predictive of neither OS nor PFS. In the 41 pts with FL grade 1–3a with DLBCL, %CR, 5-year OS, and PFS rates were 80, 84, and 60%, respectively. On the other hand, in the 18 pts with FL grade 3b with DLBCL, they were 89, 82, and 72%, respectively. The %CR and PFS rates of the latter cohort showed superior tendencies to those of the former cohort, with no statistically significant difference. Among 22 relapses, 10 were confirmed histologically: 5 DLBCL, 4 FL, and 1 HL. In 16 relapsed pts with FL grade 1–3a at initial diagnosis, 4 relapsed as FL, one each as DLBCL and HL. Two pts who had relapsed as FL and HL subsequently developed DLBCL. On the other hand, 4 out of 5 relapsed pts with FL grade 3b at the initial diagnosis relapsed as DLBCL. Additionally, the prognosis of FL/DLBCL pts was compared with that of FL and DLBCL pts. The 5-year OS rate of FL/DLBCL pts (83%) was significantly worse than that of DLBCL pts (91%, p=0.039) as well as FL pts (97%, p=0.001) (Fig 1). The 5-year PFS rate of FL/DLBCL pts (64%) was not significantly different from that of DLBCL pts (72%, p=0.120). The PFS curves (Fig 2) suggested a slight increase in progression or mortality in FL/DLBCL pts during the first 2 years. However, the FL/DLBCL pts had a low incidence of events after 2 years. The PFS curve of FL/DLBCL pts was similar to that of DLBCL pts. By multivariate analysis of pts with FL/DLBCL and DLBCL, coexisting FL components was a significant predictor of inferior OS, but not PFS. Conclusions: The PFS curve of FL/DLBCL pts was similar to that of DLBCL pts, although pts with FL/DLBCL had poorer prognosis than DLBCL pts in the rituximab era. Furthermore, in our present analysis, predominant DLBCL component was predictive of neither OS nor PFS. Disclosures: Kobayashi: Nippon Shinyaku: Research Funding; Ariad: Research Funding; Ohtsuka: Research Funding; Celgene: Research Funding; Behringer : Research Funding. Tobinai:Grant Support: Zenyaku, Chugai/Roche, GSK, Biomedics Other.

Abstract 4884 Background: Ocaratuzumab, previously known as AME-133v, is a Fc- and Fab- engineered humanized anti-CD20 monoclonal antibody designed for optimized affinity to the CD20 antigen as well as to the FcγRIIIa (CD16a) receptor on effector cells. Compared to rituximab, ocaratuzumab has been optimized with a 13- to 20-fold increase in binding affinity to CD20 and improved binding to the low-affinity (FF and FV) polymorphisms of FcγRIIIa, which are thought to predict lower response rates and shorter duration of responses to rituximab. Ocaratuzumab also demonstrates 6-fold higher antibody-dependent cellular cytotoxicity compared to rituximab. Goal: This abstract assesses the efficacy of a 100 mg/m2 dose of ocaratuzumab given once weekly for 4 weeks in previously treated follicular lymphoma patients with low affinity FcγRIIIa genotypes. Methods: A total of 9 patients (6 in US and 3 in Japan) were treated with 100mg/m2 of ocaratuzumab given once weekly for 4 weeks as part of dose escalation studies. Response assessments to treatment were performed 9 and 21 weeks after the last infusion (Japanese study) or 9 weeks after the last infusion (US study) and subsequently every 3 months until disease progression, death, or until another therapy was initiated. Responses were assessed according to the 1999 NCI Working Group criteria. Results: The 9 patients in this analysis included 5 males and 4 females, all of whom were F-carriers (4 FV and 5 FF); 1 patient was rituximab naïve. The median age of the patients at enrollment was 66 years (mean: 60 years, range: 37–75). Anti-tumor activity of ocaratuzumab was assessed as the decrease in the sum of products of the greatest diameters (SPD) from baseline. Tumor shrinkage was seen in 8 of the 9 patients (Figure 1). Three of the 9 patients achieved a response following ocaratuzumab (1 complete response and 2 partial responses). Five patients had stable disease and 1 patient had progressive disease. The median progression-free survival (PFS) was 258 days (range: 52–834 days) which is similar to the median PFS of 50 patients who received a much higher dose of ocaratuzumab (375mg/m2 per week for 4 weeks) in a phase II trial. At the end of the study, 4 patients had still not progressed. Two of those patients had PFS exceeding 800 days. Conclusions: Even when administered at approximately a quarter of the conventional dose of rituximab, ocaratuzumab demonstrated clinical activity in patients with relapsed follicular lymphoma. Administering ocaratuzumab at this low dose could substantially reduce the cost of therapy for patients with follicular lymphoma. Randomized trials will be needed to formally assess the clinical efficacy of low doses of ocaratuzumab in follicular lymphoma. Disclosures: Le: Mentrik Biotech LLC: Employment. Smith:Genentech: Speakers Bureau. Link:Genentech: Consultancy, Membership on an entity's Board of Directors or advisory committees. Tobinai:Grant support: Eli Lilly, Zenyaku, Chugai, GSK, Biomedics Other. Du:Mentrik Biotech LLC: Employment. O'Reilly:Mentrik Biotech LLC: Employment. Jain:Mentrik Biotech LLC: CEO Other, Employment, Equity Ownership, Patents & Royalties.

Abstract 795 Background: Mogamulizumab (KW-0761) is a humanized anti-CCR4 antibody engineered to exert potent ADCC by defucosylation. In a phase I study for patients with CCR4-positive T-cell malignancies, once weekly administration for 4 weeks of mogamulizumab was well tolerated up to 1.0 mg/kg, and encouraging efficacy was observed (J Clin Oncol 2010;28:1591). In a subsequent phase II study in CCR4-positive relapsed adult T-cell leukemia-lymphoma (ATL) patients, mogamulizumab exhibited an overall response rate (ORR) of 50% (J Clin Oncol 2012;30:837), leading to its approval in Japan in 2012 for relapsed/refractory ATL. In addition, a phase I/IIa study for previously treated cutaneous T-cell lymphoma (CTCL) in the USA showed an ORR of 37% (14/38) (T-CELL LYMPHOMA FORUM 2012). Based on these findings, a phase II study of mogamulizumab for relapsed peripheral T-cell lymphoma (PTCL) and CTCL was conducted in Japan. Methods: A multicenter phase II study of mogamulizumab monotherapy for patients with relapsed CCR4-positive PTCL and CTCL was conducted to evaluate efficacy, pharmacokinetic profile, and safety. The primary endpoint was ORR and secondary endpoints included progression-free survival (PFS) and overall survival (OS). At least 35 patients were needed to detect a lower limit of the 95% confidence interval (CI) exceeding the 5% threshold, with an expected ORR for mogamulizumab of 25% with 90% statistical power. Patients received intravenous infusions of mogamulizumab once per week for 8 weeks at a dose of 1.0 mg/kg. Responses were assessed after the 4th and 8th infusions of mogamulizumab by an independent efficacy assessment committee. The histopathological subtypes of PTCL were confirmed by an independent pathology review committee according to the 2008 WHO classification. In addition, we examined blood T-cell subset distributions. Results: A total of 38 patients were enrolled, and 37 patients (male/female 23/14; median age 64 years, range 33–80) received mogamulizumab. One patient was withdrawn due to an infectious complication. Twenty-nine of the 37 assessable patients had PTCL [PTCL- not otherwise specified (NOS), n=16; angioimmunoblastic T-cell lymphoma (AITL), n=12; anaplastic large cell lymphoma (ALCL)-ALK negative, n=1] and 8 had CTCL [mycosis fungoides (MF), n=7; cutaneous ALCL, n=1]. Performance status at enrollment was 0 (n=24), 1 (n=12), and 2 (n=1). The median number of prior systemic chemotherapy regimens was 2 (range 1–6). Of the 37 patients, 25 completed the schedule of 8 planned infusions. Nine patients (24%) discontinued the treatment protocol due to progressive disease and 3 due to adverse events (AEs). The ORR in 37 patients was 35% (13/37, 95% CI, 20 to 53%) with 14% having a complete response (5/37) (Table 1). By PTCL subtype, the ORR was 34% (10/29) for PTCL (3/16 for PTCL-NOS, 6/12 for AITL, and 1/1 for ALCL-ALK negative) and 38% (3/8) for CTCL (2/7 for MF and 1/1 for cutaneous ALCL). AEs possibly, probably, or definitely related to mogamulizumab monotherapy were as follows. Lymphopenia of all grades and that of grades 3–4 were observed in 78% and 70% of the 37 patients, respectively. Leukopenia of all grades and that of grades 3–4 were observed in 43% and 14% of the 37 patients. For all grades and grades 3–4, neutropenia was observed in 35% and 16%, thrombocytopenia in 35% and 3%, ALT increases in 22% and 3%, and skin eruptions in 49% and 8% of patients, respectively. Infusion-related toxicities occurred in 22%, which were all within grade 2 or lower. Fourteen severe AEs were observed in 7 patients, including a grade 3 polymyositis in 1 and grade 2 cytomegalovirus retinitis in 2. All severe AEs were improved. No grade 5 AEs were observed. Pharmacokinetic analysis demonstrated that Cmax and trough (C168h) after the 8th infusion were 45.9 ± 9.3 and 29.0 ± 13.3 μg/mL, respectively. No anti-mogamulizumab antibody has been detected. Updated results of PFS, OS, and T-cell subset analysis are being analyzed for presentation. Conclusions: Mogamulizumab monotherapy showed promising antitumor activity with acceptable toxicity profiles in patients with relapsed PTCL and CTCL, warranting further investigation. Disclosures: Ishida: Kyowa Hakko Kirin Co., Ltd,: Honoraria, Research Funding, Speakers Bureau. Ogura:Kyowa Hakko Kirin Co., Ltd,: Consultancy. Suzumiya:Kyowa Hakko Kirin Co., Ltd,: Consultancy. Inagaki:Kyowa Hakko Kirin Co., Ltd,: Consultancy. Tamura:Kyowa Hakko Kirin Co., Ltd,: Consultancy. Akinaga:Kyowa Hakko Kirin Co., Ltd,: Employment. Tomonaga:Kyowa Hakko Kirin Co., Ltd,: Consultancy. Ueda:Kyowa Hakko Kirin Co., Ltd,: endowed chair Other.

Abstract 2737 Introduction: ATL is prevalent in Japan and has the worst prognosis among T-cell malignancies. PTCL also has a poor prognosis with currently available chemotherapeutic regimens, and both would benefit from better treatment modality. Lenalidomide is an immunomodulatory agent with direct tumoricidal and antiproliferative activity, and is approved for multiple myeloma (MM) in combination with dexamethasone after at least 1 prior therapy and for transfusion-dependent anemia due to low- or intermediate-1-risk myelodysplastic syndromes associated with 5q deletion. We conducted a phase 1 study of lenalidomide in patients with relapsed ATL or PTCL to establish the recommended dose and schedule for a subsequent phase 2 study. Patients and Methods: This multicenter, phase 1, dose-escalation study assessed the safety, maximum tolerated dose (MTD), pharmacokinetics, and efficacy in patients with relapsed advanced ATL or PTCL. Dose-escalation was conducted according to the standard 3+3 design. Up to one PTCL patient was allowed to be included in each cohort of 3 patients. Patients in Cohort 1 received oral lenalidomide 25 mg daily on Days 1–21 of a 28-day cycle. Patients in Cohorts 2 and 3 received 25 and 35 mg/day, respectively, on each day of the 28-day cycle. Dose-limiting toxicity (DLT) was defined as febrile neutropenia lasting 5 or more days; thrombocytopenia (platelets Results: From July 2010–June 2012, 13 Japanese patients (9 ATL and 4 PTCL; age 32–74 years [median, 64]; 1–11 prior therapies [median, 1]) were enrolled: 3 in Cohort 1, 6 in Cohort 2, and 4 in Cohort 3. The 3 patients in Cohort 1 received lenalidomide for 21, 103, and 637 days, respectively, until PD with no instances of DLT. In Cohort 2, 1 patient experienced DLT (thrombocytopenia, platelets 75% reduction in lymph nodes, which lasted for 282 days. PK profiles of patients in the study were generally consistent with that observed in Japanese MM patients. Plasma exposure of lenalidomide increased with increasing dose with a mean Cmax on Day 1 for 25 mg and 35 mg of 493 ng/mL and 628 ng/mL, respectively, and a mean AUC24 of 2774 ng/mL and 3062 ng/mL, respectively. There was no evidence of accumulation following multiple dosing for 8 days. Conclusions: This phase 1 study identified lenalidomide 25 mg daily per 28-day cycle as the dose and schedule for a subsequent phase 2 study in patients with ATL or PTCL. Based on the preliminary evidence of antitumor activity in ATL and PTCL patients, a phase 2 study in patients with relapsed ATL in Japan is planned. Disclosures: Off Label Use: Lenalidomide (CC-5013) is an investigational agent in Japan; this abstract assesses its use in adult ATL patients. Tobinai:Merck: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Mundipharma: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Zenyaku: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Genzyme: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Eisai: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Symbio: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Eli Lilly: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Kyowa-Kirin: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Biomedics: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Solasia Pharma: Clinical trials, Clinical trials Other, Research Funding; Novartis: Research Funding; Johnson & Johnson: Research Funding; Pfizer: Research Funding; GSK: Research Funding; Chugai/Roche: Research Funding; Takeda: Clinical trials, Clinical trials Other, Research Funding.

Abstract 1633 Background: Inotuzumab ozogamicin (INO) is a humanized anti-CD22 antibody conjugated to calicheamicin, a potent antitumor antibiotic. CD22 is expressed on the majority of B-cell non-Hodgkin's lymphomas (NHL). This phase 1 study was conducted to identify the maximum tolerated dose (MTD) of INO when given in combination with R-CVP (rituximab 375 mg/m2, cyclophosphamide 750 mg/m2, and vincristine 1.4 mg/m2 all on Day 1 and prednisone 40 mg/m2on Days 1–5) every 21 days, and to obtain preliminary safety and efficacy data for this regimen. Patients and methods: The study enrolled patients with relapsed/refractory CD22+ B-cell NHL. The dose-escalation part (Part 1; previously presented) identified the MTD as INO 0.8 mg/m2 given on Day 2 with R-CVP q3wks [Blood. 2011;118:3715]. Subsequent cohorts included the MTD confirmation cohort (Part 2) and MTD expansion cohort (Part 3), for collection of additional safety and preliminary efficacy data. Untreated patients who were not candidates for anthracyclines were allowed in Part 2 and Part 3 of the study. In Part 2 (n = 10), confirmation of the MTD required a dose-limiting toxicity (DLT) rate of Results: In Parts 2 and 3, a total of 32 patients with follicular lymphoma (FL; n = 15), diffuse large B-cell lymphoma (DLBCL; n = 16), or mantle cell lymphoma (n = 1) were enrolled. CD22 expression was confirmed by immunohistochemistry or flow cytometry prior to enrollment. The median age was 65 years (range, 44–81 years); 34% of patients had 1 prior anti-lymphoma regimen, 34% had 2, 28% had ≥3, and 3% (n = 1) had no previous therapy (median, 2; range, 0–6). The median number of cycles received was 5 (range, 1–6). In Part 2, the MTD was confirmed as standard-dose R-CVP plus INO 0.8 mg/m2, with 2 of 10 patients presenting with a DLT (grade 3 increase in alanine/aspartate aminotransferases [ALT/AST] and grade 4 neutropenia requiring granulocyte-colony stimulating factor). Four patients discontinued due to AEs after 2 cycles (n = 1), 3 cycles (n = 2), and 5 cycles (n = 1), respectively. Across Parts 2 and 3, the most common treatment-related AEs (all grades) were thrombocytopenia (78%), neutropenia (66%), fatigue (53%), constipation (50%), leukopenia (50%), and nausea (41%); the most common grade 3/4 AEs included neutropenia (63%), thrombocytopenia (53%), leukopenia (38%), lymphopenia (31%), increased ALT (9%), increased AST (6%), and febrile neutropenia (6%). There was 1 case of treatment-related fatal pneumonia associated with grade 4 neutropenia. Ten patients discontinued study treatment due to AEs, with thrombocytopenia or delayed recovery from thrombocytopenia being the leading AE causing study drug discontinuation (n = 9 [grade 1/2, n = 6; grade 3/4, n = 3]). The best overall response (ORR; partial + complete response [CR]) from Part 2 and 3 (31 evaluable patients) was 77% (n = 24/31), including 29% (n = 9/31) with CR. Of patients with FL, the ORR was 100% (n = 15/15), including 53% (n = 8/15) with CR. Of patients with DLBCL, the ORR was 60% (n = 9/16), including 7% (n = 1/16) with CR. Conclusions: Results from this phase I study showed that R-CVP in combination with INO 0.8 mg/m2 may have acceptable toxicity and promising activity in patients with relapsed or refractory CD22+ B-cell NHL, based on the response rates in FL and DLBCL. The most common grade 3/4 AEs were hematological toxicities, notably thrombocytopenia and neutropenia. Follow-up for progression-free survival and overall survival is currently ongoing; however, the observed results warrant additional study in both indolent and aggressive B-cell NHL. Disclosures: Ogura: Pfizer Inc: Research Funding. Hatake:Pfizer Inc: Research Funding. Davies:Pfizer Inc: Research Funding. Crump:Pfizer, Celgene, Roche, Millennium, Seattle Genetic: Membership on an entity's Board of Directors or advisory committees. Tobinai:Merck, Zenyaku, Symbio, Biomedics, Pfizer, GSK, Chugai/Roche: Research Funding. Smith:Pfizer Inc: Research Funding. Offner:Pfizer Inc: Research Funding. Wang:Pfizer Inc: Employment, Equity Ownership. Ishibashi:Pfizer Inc: Employment, Equity Ownership. Paccagnella:Pfizer Inc: Employment, Equity Ownership. Vandendries:Pfizer Inc: Employment, Equity Ownership. MacDonald:Roche Canada: Membership on an entity's Board of Directors or advisory committees, Research Funding.

Abstract 881 Background. The Japan Clinical Oncology Group (JCOG)-Lymphoma Study Group (LSG) conducted 3 clinical trials in the 1990s for aggressive ATL, i.e. acute, lymphoma, and unfavorable chronic types, associated with human T-lymphotropic virus type-I. The prognosis of aggressive ATL patients (pts) is still poor, but the 5-year survival rate was improved from 5% in the 1980s to 15% in a JCOG study in late 1990s. To characterize long-term survivors and to develop a new predictive model for aggressive ATL, we performed a combined analysis of enrolled pts in the 3 JCOG studies. Methods. A total 276 pts with aggressive ATL were registered in 3 consecutive JCOG-LSG trials exclusively against aggressive ATL, i.e. JCOG9109, a phase II (pII) study of LSG11 consisting of pentostatin, VCR, ETP, PSL and DOX; JCOG9303, a pII study of LSG15 consisting of VCAP-AMP-VECP; and JCOG9801, a pIII study comparing modified (m) LSG15 with CHOP-14. The pts were analyzed for their prognosis, the effects of central nervous system (CNS) prophylaxis in the protocol treatment and allogeneic hematopoietic cell transplantation (allo-HCT) after the protocol treatment, and the outcome of long-term survivors with a follow-up survey. To build a predictive index, multivariate analyses with a Cox proportional hazard model were conducted using the test sample of 193 pts without missing covariate data from the entire cohort of 276 pts. Validation was carried out using external data for 136 pts, who were independent from those included in the JCOG studies. Results. The MST, 5- and 8-yesr OS rates of the entire cohort of 276 pts were 10.9 months, 13.6% and 10.0%, respectively. The median and longest follow-up periods were 10.9 months and 17.5 years, respectively. The differences of CNS prophylaxis by each regimen did not significantly affect the CNS relapse rate. We analyzed 269 eligible pts (acute 170, lymphoma 78, chronic 21). In 67 pts who survived for more than 2 years, there were 38 (22%) pts with acute type, 21 (28%) with lymphoma type and 5 (24%) with chronic type. The major proportion of relapse in pts with acute type occurred within 2 years after initiating chemotherapy, and occurred earlier than in pts with other types. In 37 pts who survived for more than 5 years (acute 22 (13%), lymphoma 8 (10%), chronic 7 (33%)), there were no disease-related deaths among lymphoma type pts, which was in contrast to the 10 disease-related deaths that occurred in pts with acute or chronic type during the follow-up period. The numbers of pts achieving CR and the other response category at the end of the protocol treatment were 24 and 13 in the 37 pts who survived for more than 5 years, respectively, and 11 and 1 in the 12 who survived for more than 10 years, respectively. Six of the 37 pts who survived for more than 5 years and 2 of 12 who survived for more than 10 years had received allo-HCT. In a test sample of 193 pts, two unfavorable factors associated with OS, high calcium (Ca) level and ECOG performance status (PS) of 2 to 4, were identified. The hazard ratio (HR) [95% confidence interval (CI)] of Ca and PS were 1.574 [1.09–2.28] and 1.554 [1.12–2.16], respectively. Considering the potential for clinical usage, four categories using these two factors were combined into a predictive index with 2 strata, thus resulting in pts with both Ca=5.5 mEq/l and/or PS 2 to 4, respectively (Fig 1). The HR [95% CI] was 1.926 [1.42–2.61]. The predictive model was reproducible in the validation set. Conclusion. There were no disease-related deaths in 8 lymphoma type pts who survived for more than 5 years, suggesting that about 10% of pts with lymphoma type may be curable. We developed a predictive model for aggressive ATL based on Ca and PS, however, the MST was only 14.3 months even in the better prognostic group. To further improve the outcome, a pII trial of VCAP-AMP-VECP followed by allo-HCT (JCOG0907) and a randomized pII study of VCAP-AMP-VECP with or without anti-CCR4 antibody are underway. Disclosures: No relevant conflicts of interest to declare.

Abstract 3715 Background: Inotuzumab ozogamicin (INO) is a humanized anti-CD22 antibody conjugated to calicheamicin, a potent antitumor antibiotic. CD22 is expressed on the majority of B-cell non-Hodgkin lymphomas (NHL). Although safety and preliminary efficacy data of INO as monotherapy and in combination with rituximab have previously been reported, there is no report of combination use of INO with chemotherapy. This phase I study evaluated the safety of INO in combination with chemotherapy (R-CVP regimen) in patients with relapsed or refractory CD22+ B-cell NHL. Preliminary efficacy data were also collected. Patients and Methods: Patients with either relapsed or refractory CD22+ B-cell NHL and at least 1 prior treatment regimen, including rituximab and chemotherapy, were enrolled in a phase I dose-finding study (part 1), with a planned expansion cohort (n = 10) to confirm the safety and tolerability of the maximum tolerated dose (MTD; part 2), and a further expansion cohort (n = 20) to estimate antitumor activity (part 3). In the dose-escalation study, INO (0.8 mg/m2) was given on Day 2 with R-CVP (rituximab 375 mg/m2, vincristine 1.4 mg/m2, and escalating doses of cyclophosphamide 375, 550, and 750 mg/m2 all on Day 1; prednisone 40 mg/m2 on Days 1–5) q3wks. After the highest dose of cyclophosphamide was evaluated for safety, INO was escalated to 1.3 mg/m2. Dose reductions and/or dose delays were performed, as needed, based on toxicities. The current analysis presents the completed dose-escalation phase, with preliminary safety and efficacy data. Results: 23 patients with follicular (FL; n = 15), mantle cell (n = 3), diffuse large B-cell (n = 3), or small lymphocytic (n = 1) lymphomas (missing diagnosis, n = 1) have been enrolled so far: 65% of patients were male, and the median age was 62 years (range, 42–74 years). In part 1 of the study, approximately 50% of patients had received 2 or more prior chemotherapy regimens, and all had received prior rituximab. As of the time of this analysis, 11 patients had completed at least 5 treatment cycles (ie, ≥105 days on study drug). No dose-limiting toxicities (DLTs) were reported with INO 0.8 mg/m2 plus R-CVP at the lower doses of cyclophosphamide (375 and 550 mg/m2). At a dose level of INO 0.8 mg/m2 plus full-dose R-CVP (cyclophosphamide 750 mg/m2), 1 out of 6 patients had a DLT of grade 4 neutropenia requiring treatment with granulocyte colony-stimulating factor (G-CSF). At a dose level of INO 1.3 mg/m2 plus R-CVP, 2 out of 3 patients had a total of 3 DLTs (acute hepatitis, thrombocytopenia, and neutropenia requiring G-CSF). Therefore, the MTD was determined to be rituximab 375 mg/m2, vincristine 1.4 mg/m2, and cyclophosphamide 750 mg/m2 all given on Day 1, INO 0.8 mg/m2 given on Day 2, and prednisone 40 mg/m2 given on Days 1 through 5 of each 3-week cycle. Treatment-emergent grade ≥3 adverse events included neutropenia (57%), lymphopenia (52%), leukopenia (35%), thrombocytopenia (30%), increased alanine aminotransferase (9%), increased aspartate aminotransferase (4%), decreased blood sodium (4%), fatigue (4%), febrile neutropenia (4%), hyperbilirubinemia (4%), hypoxia (4%), lethargy (4%), pleural effusion (4%), and pollakiuria (4%). Enrollment is continuing in parts 2 and 3 of the study. Preliminary efficacy data from the escalation portion of the study (n = 15 evaluable patients) is notable for an overall response rate (ORR) of 87% (33% with complete response; 53% with partial response). In patients with FL, the ORR was 100% (45% with complete response). Conclusions: INO 0.8 mg/m2 appears to be tolerable when given in combination with full dose R-CVP chemotherapy. DLTs were hematologic and hepatic, and encouraging signs of antitumor activity have been reported. Disclosures: MacDonald: Roche Canada: Honoraria, Research Funding. Davies:Pfizer Inc: Research Funding. Sangha:Roche: Honoraria; Boehringer Ingelheim: Honoraria. Crump:Millenium: Consultancy, Honoraria; Celgene: Consultancy, Honoraria; Roche Canada: Consultancy, Honoraria; Pfizer Inc: Consultancy, Honoraria; Seattle Genetics: Consultancy, Honoraria; Janssen-Ortho: Consultancy, Honoraria. Thieblemont:Assistance Publique - Hôpitaux de Paris: Employment; Institut National du Cancer - INCa [French National Cancer Institute]: Research Funding. Ishibashi:Pfizer Inc: Employment, Equity Ownership. Hua:Pfizer Inc: Employment, Equity Ownership. Paccagnella:Pfizer Inc: Employment, Equity Ownership, Patents & Royalties. Vandendries:Pfizer Inc: Employment, Equity Ownership. Kobayashi:Ohtsuka Pharmaceutical: Research Funding; Nippon Shiyaku: Honoraria; BMS: Honoraria. Tobinai:Bayer: Research Funding; Celgene: Research Funding; Chugai: Research Funding; Eli Lilly: Research Funding; Genzyme: Research Funding; GSK: Research Funding; Kyowa Hakko Kirin: Research Funding; Janssen: Research Funding; MSD: Research Funding; Mundipharma: Research Funding; Novartis: Research Funding; Pfizer Inc: Research Funding; Symbio: Research Funding; Zenyaku: Research Funding.

Abstract 5132 BACKGROUND AND PURPOSE: Although bortezomib is widely used both in newly diagnosed and in relapsed/refractory multiple myeloma (MM) patients (pts), it is only approved for relapsed/refractory MM in Japan. To evaluate safety, pharmacokinetics (PK) and efficacy of bortezomib combined with melphalan and prednisolone (MPB) therapy, we conducted a phase I/II study in untreated Japanese MM pts who were ineligible for hematopoietic stem cell transplant (HSCT). METHODS: This was a dose-escalation study designed to determine the recommended dose (RD) of bortezomib in combination with melphalan and prednisolone by estimating the maximum tolerated dose based on dose-limiting toxicity (DLT) in the phase I portion, and to investigate the overall response rate (ORR; CR+PR) and safety of MPB therapy in the phase II portion. Particularly, a continuity of treatment was historically compared with a global phase III study (VISTA trial), and the incidence of interstitial lung disease was assessed. Pts were planned to receive 9 cycles (6-week/cycle) of bortezomib (days 1, 4, 8, 11, 22, 25, 29, and 32 in cycles 1 to 4; and days 1, 8, 22, and 29 in cycles 5 to 9) plus melphalan (9 mg/m2) and prednisolone (60 mg/m2) administered on days 1 to 4 of each cycle. RESULTS: A total of 101 pts were enrolled and 99 received at least one dose of the study treatment. The median age was 72 years (range: 48–84), and 5 were under 65 years. The most common type of MM was IgG (66%), followed by IgA (25%). In the phase I portion, each 6 pts were assigned to receive 0.7 mg/m2 and 1.0 mg/m2, and no DLTs were observed in either dose level. In 1.3 mg/m2 group, 2 events of DLTs (enterocolitis infections and ileus) occurred in 1 of the 6 pts. Therefore, 1.3 mg/m2 was determined as RD for the subsequent phase II portion. In the phase I portion, PK parameters, Cmax (120 ng/mL), tmax (0.078 h) and AUC24 (74.1 ng·h/mL) in plasma bortezomib at RD, were similar to those in VISTA trial and no apparent drug-drug interaction was observed in the PK of bortezomib in the MPB therapy. The response was evaluated in 17 pts in the phase I portion, and in 86 pts in the phase II portion (including 5 pts receiving 1.3 mg/m2 in the phase I portion). In the phase I portion, all 6 pts in 0.7 mg/m2 achieved partial response (PR). In 1.0 mg/m2, 3 pts achieved complete response (CR), and 2 pts achieved PR out of 6 pts. In 1.3 mg/m2, 2 pts achieved CR, and 2 pts achieved PR out of 6 pts. In the phase II portion, 17 pts achieved CR, and 43 pts achieved PR. The ORR was 70% (60/86) with the two-sided 90% confidence interval of the ORR was 61% to 78%. This ORR (70%) was comparable with the ORR (71%) in the MPB group of VISTA trial. The median time to response was 51 days (range: 43–82). In the phase II portion, the frequent (≥50%) adverse events (AEs) were hematologic toxicities (neutropenia, lymphopenia, thrombocytopenia and anemia), diarrhea, nausea, constipation, rash, elevated c-reactive protein, elevated lactate dehydrogenase, weight loss, anorexia, hyponatremia, peripheral neuropathy, leukocytosis and hepatic dysfunction. The incidence of AEs was generally higher and AEs were generally more severe in this study compared with the MPB group of VISTA trial, but most of the AEs were clinically manageable. Incidence of interstitial lung disease (interstitial pneumonia, pneumonitis and hypoxia) was 10% (9/87) in the phase II portion (with chest X-ray and oximeter analysis periodically and arterial oxygen partial pressure and chest CT as needed) and 1% (4/340) in the MPB group of VISTA trial, respectively. There was no death due to lung disorder in this study. Only rare cases of grade 3 events (pneumonitis and hypoxia) or serious events were reported, and all of the events were clinically manageable. Whereas the incidence of peripheral neuropathy (grade 3 and 4), the median number of treatment cycles (range) and the median dose intensity for bortezomib in the first 4 cycles were 10% (9/87), 5 cycles (1–9) and 6.86 mg/m2/cycle in the phase II portion of this study, those in the MPB group of VISTA trial were 14% (46/340), 9 cycles (1–9) and 8.32 mg/m2/cycle, respectively. CONCLUSION: This phase I/II study in Japan suggests that the RD of bortezomib in MPB therapy is 1.3 mg/m2 and MPB therapy in newly diagnosed Japanese MM pts ineligible for HSCT is effective as well as those in VISTA trial. Further investigation is needed to refine the administration schedule of this combination in Japanese pts. Disclosures: No relevant conflicts of interest to declare.