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Angioimmunoblastic T-cell lymphoma (AITL) is a unique subtype of peripheral T-cell lymphoma (PTCL) with distinct clinicopathologic features and poor prognosis. We performed a subset analysis of 282 patients with AITL enrolled between 2006 and 2018 in the international prospective T-cell Project (NCT01142674). The primary and secondary end points were 5-year overall survival (OS) and progression-free survival (PFS), respectively. We analyzed the prognostic impact of clinical covariates and progression of disease within 24 months (POD24) and developed a novel prognostic score. The median age was 64 years, and 90% of patients had advanced-stage disease. Eighty-one percent received anthracycline-based regimens, and 13% underwent consolidative autologous stem cell transplant (ASCT) in first complete remission (CR1). Five-year OS and PFS estimates were 44% and 32%, respectively, with improved outcomes for patients who underwent ASCT in CR1. In multivariate analysis, age ≥60 years, Eastern Cooperative Oncology Group performance status >2, elevated C-reactive protein, and elevated β2 microglobulin were associated with inferior outcomes. A novel prognostic score (AITL score) combining these factors defined low-, intermediate-, and high-risk subgroups with 5-year OS estimates of 63%, 54%, and 21%, respectively, with greater discriminant power than established prognostic indices. Finally, POD24 was a powerful prognostic factor with 5-year OS of 63% for patients without POD24 compared with only 6% for patients with POD24 (P < .0001). These data will require validation in a prospective cohort of homogeneously treated patients. Optimal treatment of AITL continues to be an unmet need, and novel therapeutic approaches are required.

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.

BACKGROUND: CNS directed chemotherapy (chemo) reduces the risk of CNS relapse of ALL, but the optimal way to measure baseline CNS involvement is controversial. Baseline CSF testing can provide risk stratification and often dictates CNS prophylaxis (ppx) during initial treatment. Despite advances, up to 10% of adults still suffer CNS relapse (Blood 2008;112:1646, Cancer 2014;120:3660). Testing typically focuses on conventional cytospin (CC) of CSF, but CC is limited by interobserver variability and insensitivity (Blood 2014;124:3799). Alternatively, MFC is more sensitive (ASH 2018, #658). A previous study in children with ALL found leukemia detection in the CNS by CC or MFC at diagnosis to be associated with an increased risk of both isolated bone marrow and any CNS relapse (ASH 2018, #657). To our knowledge, this use of MFC has not specifically been studied in hyperCVAD, a commonly used chemotherapy regimen for the initial treatment of adult ALL. We hypothesized that baseline lymphoblast detection in the CSF by MFC is predictive of CNS relapse. METHODS: We included data collected from 11/6/07 to 6/22/20. Patients (pts) ≥18 years old who received ≥4 cycles (equivalent of cycle 2B) of hyperCVAD as first-line therapy were eligible. Pts must have had MFC done on CSF at baseline. Pts with mixed phenotype or insufficient follow-up data were excluded. CNS ppx with hyperCVAD historically uses intra-CSF (ie, intrathecal or intraventricular) methotrexate 12 mg on day 2 and cytarabine 100 mg on day 8 of each cycle for 6-12 doses without cranial radiation, though all patients were treated per physician discretion. CC and MFC results were taken from clinical reports and verified by an independent hematopathologist (Dr. Cherian). Baseline CSF positivity (CSF+) and negativity (CSF-) were defined by MFC, with any percentage of lymphoblasts considered CSF+. COG definitions of CNS status by CC were also used (J Clin Oncol 2016;34:2380). Univariate Cox models evaluated associations to CNS relapse. Kaplan-Meier curves were used to estimate the probabilities of overall survival (OS) and cumulative incidence of CNS relapse. RESULTS: We identified 92 eligible pts. Disease and treatment characteristics are summarized in Table 1, and results of initial CSF testing are shown in Table 2. Twenty-one pts were CSF+ by MFC at baseline: by CC, 6 of these were positive, 6 were negative, 7 were equivocal (ie, morphologic review was unable to rule out blasts), and 2 did not have baseline CC. None were positive by CC but negative by MFC. Eight of 29 (38%) with circulating blasts had a traumatic (>10 RBC/uL of CSF) first lumbar puncture (LP). Of these 8, 4 (50%) were CSF+. Five (5%) pts had an Ommaya reservoir placed during treatment. Pts received a median of 8 doses of intra-CSF chemo (range, 5-52). All but 7 pts (8%) received a combination of methotrexate and cytarabine like above. Twenty CSF+ pts (95%) achieved CSF- after a median of 1 dose of intra-CSF chemo (range, 1-5). Out of the 71 CSF- pts, none became CSF+ during initial treatment despite being tested a median of 5 times (range, 2-10). Eight pts (9%) had CNS relapse (3 isolated, 5 concurrent medullary relapse). Comparisons between baseline CSF testing, intra-CSF treatment, and CNS relapse are shown in Table 2. CSF+ pts received significantly greater doses of intra-CSF chemo. Of the 21 CSF+ pts, 5 (24%) had CNS relapse (2 isolated, 3 concurrent), and out of the 71 CSF- pts, 3 (4%) had CNS relapse (1 isolated, 2 concurrent; p=0.014). Among univariate models of CSF+ vs -, traumatic LP vs not, B vs T lineage, LDH, and WBC, only CSF+ was significantly associated with CNS relapse (hazard ratio 4.8, 95% confidence interval [CI] 1.2-20, p=0.031). Estimated 3-year cumulative incidence of CNS relapse for CSF+ was 15% vs 3.3% for CSF- (Figure 1). Median OS for the whole cohort was not reached, with estimated 3-year OS of 74% (95% CI, 65%-84%). CONCLUSIONS: MFC of CSF is more predictive of CNS relapse risk than CC in the context of front-line hyperCVAD, questioning the use of CC if MFC is performed. Further, CNS relapses were significantly more frequent when CSF+ despite administration of significantly more intra-CSF chemo. Traumatic LP per se did not increase risk of CNS relapse if CSF- by MFC. Surveillance during treatment by MFC in CSF- pts identified no cases of occult CNS relapse, arguing against this routine practice. Future studies should consider incorporating MFC of CSF into risk-adapted CNS-directed treatment strategies. Disclosures Shustov: Seattle Genetics: Research Funding. Becker:Accordant Health Services/Caremark: Membership on an entity's Board of Directors or advisory committees; Cardiff Oncology: Research Funding; SecuraBio: Research Funding; Novartis: Research Funding; Pfizer: Research Funding; JW Pharmaceutical: Research Funding; Glycomimetics: Research Funding; Abbvie: Research Funding; Bristol Myers Squibb: Research Funding; Invivoscribe: Research Funding. Oehler:Takeda: Consultancy; BMS: Consultancy; Pfizer, Inc: Research Funding. Halpern:Bayer: Other; Novartis: Other; Jazz Pharmaceuticals: Other; Imago BioSciences: Other; Tolero Pharmaceuticals: Research Funding. Walter:Amgen: Consultancy, Research Funding; Arog: Research Funding; Argenx: Consultancy; Aptevo: Consultancy, Research Funding; Amphivena: Current equity holder in publicly-traded company; Agios: Consultancy, Research Funding; StemLine: Research Funding; Selvita: Research Funding; Seattle Genetics: Research Funding; Race Oncology: Consultancy; Pfizer: Consultancy, Research Funding; New Link Genetics: Consultancy; Macrogenics: Research Funding; Kite: Consultancy; Jazz: Consultancy, Research Funding; ImmunoGen: Research Funding; Genentech: Consultancy; Daiichi: Consultancy; Celgene: Consultancy, Research Funding; Boston Biomedical: Consultancy; BiVictriX: Consultancy; BioLineRx: Consultancy, Research Funding; Astellas: Consultancy. Godwin:Pfizer Inc.: Research Funding; Immunogen Inc.: Research Funding. Cassaday:Kite/Gilead: Consultancy, Research Funding; Merck: Research Funding; Seattle Genetics: Current Employment, Current equity holder in publicly-traded company; Amgen: Consultancy, Research Funding; Vanda Pharmaceuticals: Research Funding; Pfizer: Honoraria, Research Funding.

Background: Classical Hodgkin lymphoma (CHL) patients (pts) requiring second line therapy may still be cured with multiagent salvage chemotherapy followed by autologous stem cell transplant (ASCT). The likelihood of long-term remission following ASCT for relapsed/refractory (R/R) CHL is predicted by response to pre-ASCT salvage therapy (Moskowitz et al. Blood 2012). The anti-CD30 antibody-drug conjugate brentuximab vedotin (BV) is effective as a single agent in R/R CHL. We hypothesized that concurrent therapy with dose-dense BV and 2 cycles of ICE would be safe, efficient, and produce high CR rates necessary for superior outcomes after ASCT. (#NCT02227199) Methods: Patients (pts) ≥ 18 years old with first relapse or primary refractory CD30+ cHL were eligible for this IRB-approved prospective clinical trial. Treatment included BV on Days 1 and 8 at either 1.2 or 1.5 mg/kg (based on 3+3 dose-escalation schema; capped at 150 mg), ifosfamide and mesna 5 g/m2 each on Day 2, carboplatin AUC 5 (capped at 800 mg) on Day 2, and etoposide 100 mg/m2 daily on Days 1-3. Two 21-day cycles were given with G-CSF support. BV 1.5 mg/kg was selected as the phase II dose based on reported dose escalation data (ASH 2016, #1834). PET was performed after Cycle 2, with response assigned per Cheson 2007. Stem cells were collected after Cycle 2 at discretion of treating investigator. Peripheral blood (PB) pre- and post-treatment, stem cell (PBSC) product, and (when available) archived formalin-fixed paraffin-embedded tissue (FFPET) from presentation and relapse were collected for correlative studies. Pre-treatment PB cytokine levels were measured by Luminex. Immunohistochemistry (IHC) on FFPET identified components of inflammatory microenvironment. The primary endpoint was to determine the MTD and CR rate after 2 cycles. Secondary endpoints included PFS, OS, stem cell collection, and molecular correlates. Results: All 45 pts have enrolled and completed study treatment, including 42 pts who were assigned treatment at the MTD of 1.5 mg/kg on day 1 and 8 of each cycle. Median age was 31 (range, 21-61). 16/45 (36%) were male, 28/45 (62%) had primary refractory disease, and 11/45 (24%) had extranodal involvement at relapse. 41 pts completed both cycles of therapy. One pt experienced grade 5 multi-system organ-failure during cycle 1, one pt was removed from protocol due to non-compliance, and two pts omitted cycle 2 due to toxicity (grade 4 sepsis, grade 3 Sweet syndrome attributable to G-CSF). 2 pts received all ICE dosing, but omitted at least one dose of BV due to toxicity. In addition, 13/41 (32%) pts delayed initiation of cycle 2 by a median of 7 days (range 6-17) due to toxicity, primarily elevated transaminases (10/13, 77%). 16/45 (36%) pts experienced neuropathy, but grade ≥2 neuropathy was rare (3/45, 7%). Other grade 3-4 non-hematologic toxicity included febrile neutropenia/sepsis (11%), elevated ALT (11%), hyperglycemia (7%), pulmonary embolism (4%), and elevated AST (4%). 36 pts underwent PBSC collection at our institution and had all data available for analysis. 30/36 pts were able to collect at least 5x106 CD34+ cells/kg. 5/6 of the remaining pts were still able to proceed with ASCT with the amount collected, and the other pt was not deemed an ASCT candidate due to social reasons. 37/43 pts (86%) who were evaluable for response proceeded to ASCT (2 subjects declined ASCT, 2 were ineligible due to social issues, one was lost to follow up, one remained chemorefractory despite additional salvage chemotherapy). Only 4/37 pts who received an ASCT subsequently relapsed. 43 pts were evaluable for efficacy. Overall response rate (ORR) and CR for all enrolled patients were 91% and 74%, respectively. Among primary refractory pts, ORR and CR were 86% and 68%, respectively. With a median follow-up of 26.5 months (range 0.7-62) months, 2-year PFS and OS were 82% and 98%. Updated results will be presented at the meeting. Conclusions: BV-ICE is a rapid, active and tolerable salvage regimen for R/R CHL patients, including those with primary refractory disease. Efficacy results are comparable to previously presented BV-chemo salvage combinations often delivered over longer durations. BV-ICE should be considered in R/R CHL prior to ASCT. Figure Disclosures Lynch: Juno Therpeutics: Research Funding; TG Therapeutics: Research Funding; Takeda: Research Funding; Incyte: Research Funding; Rhizen Pharmaceuticals: Research Funding; Bayer: Research Funding; Cyteir: Research Funding; MorphoSys: Consultancy; Genentech: Research Funding. Cassaday:Merck: Research Funding; Amgen: Consultancy, Research Funding; Pfizer: Honoraria, Research Funding; Vanda Pharmaceuticals: Research Funding; Seattle Genetics: Current Employment, Current equity holder in publicly-traded company; Kite/Gilead: Consultancy, Research Funding. Smith:AstraZeneca: Research Funding; Acerta Pharma BV: Research Funding; Beigene: Consultancy; Millenium/Takeda: Consultancy; AstraZeneca: Consultancy; Seattle Genetics: Research Funding; Portola: Research Funding; Pharmacyclics: Research Funding; Merck: Research Funding; Incyte: Research Funding; Ignyta: Research Funding; Genentech: Research Funding; De Novo Biopharma: Research Funding; Bristol Meyers Squibb: Research Funding; Bayer: Research Funding; Ayala: Research Funding; Karyopharm: Consultancy. Fromm:Merck: Research Funding. Cowan:Abbvie: Research Funding; Bristol Myers Squibb: Research Funding; Cellectar: Consultancy; Sanofi: Consultancy; Janssen: Consultancy, Research Funding. Shadman:Mustang Bio, Celgene, Pharmacyclics, Gilead, Genentech, Abbvie, TG therapeutics, Beigene, Astra Zeneca, Sunesis, Beigene: Research Funding; Abbvie, Genentech, Astra Zeneca, Sound Biologics , Pharmacyclics, Verastem, ADC therapeutics, Beigene, Cellectar, BMS, Morphosys and Atara Biotherapeutics: Consultancy. Shustov:Seattle Genetics: Research Funding. Till:Mustang: Patents & Royalties, Research Funding. Ujjani:MorphoSys: Consultancy; Genentech: Consultancy, Honoraria; Atara: Consultancy, Honoraria; Gilead/Kite: Consultancy, Research Funding; Verastem Oncology: Consultancy, Honoraria; Abbvie: Consultancy, Honoraria, Research Funding; AstraZeneca: Consultancy, Honoraria, Research Funding. Gopal:IgM bio, BMS, merck: Research Funding; imab bio, takeda,astrazeneca,gilead: Research Funding; Seattle Genetics; Janssen; Takeda; IgM Bio; IMab Bio; BMS; Astra Zeneca; Merck; Gilead: Research Funding; Seattle Genetics; Janssen; IMab Bio; TG Therapeutics; Astra Zeneca; Merck; Gilead; ADC Therapeutics; Nurix; TG therapeutics, Cellectar; Actinium: Consultancy.

The peripheral T-cell lymphomas (PTCLs) are uniquely sensitive to epigenetic modifiers. Based on the synergism between histone deacetylase inhibitors and hypomethylating agents that we established in preclinical PTCL models, we conducted a phase 1 study of oral 5-azacytidine (AZA) and romidepsin (ROMI) in patients with advanced lymphoid malignancies, with emphasis on PTCL. According to a 3 + 3 design, patients were assigned to 1 of 7 cohorts with AZA doses ranging from 100 mg daily on days 1 to 14 to 300 mg daily on days 1 to 21, ROMI doses ranging from 10 mg/m2 on days 8 and 15 to 14 mg/m2 on days 8, 15, and 22, with cycles of 21 to 35 days. Coprimary end points included maximum tolerated dose (MTD) and dose-limiting toxicity (DLT). We treated a total of 31 patients. The MTD was AZA 300 mg on days 1 to 14 and ROMI 14 mg/m2 on days 8, 15, and 22 on a 35-day cycle. DLTs included grade 4 thrombocytopenia, prolonged grade 3 thrombocytopenia, grade 4 neutropenia, and pleural effusion. There were no treatment-related deaths. The combination was substantially more active in patients with PTCL than in those with non-T-cell lymphoma. The overall response rate in all, non-T-cell, and T-cell lymphoma patients was 32%, 10%, and 73%, respectively, and the complete response rates were 23%, 5%, and 55%, respectively. We did not find an association between response and level of demethylation or tumor mutational profile. This study establishes that combined epigenetic modifiers are potently active in PTCL patients. This trial was registered at www.clinicaltrials.gov as NCT01998035.

The primary cutaneous CD30+ lymphoproliferative disorders are a family of extranodal lymphoid neoplasms that arise from mature postthymic T cells and localize to the skin. Current classification systems recognize lymphomatoid papulosis (LyP), primary cutaneous anaplastic large cell lymphoma, and borderline cases. In the majority of patients, the prognosis of primary cutaneous CD30+ lymphoproliferative disorders is excellent; however, relapses are common, and complete cures are rare. Skin-directed and systemic therapies are used as monotherapy or in combination to achieve the best disease control and minimize overall toxicity. We discuss 3 distinct presentations of primary cutaneous CD30+ lymphoproliferative disorder and present recommendations for a multidisciplinary team approach to diagnosis, evaluation, and management of these conditions in keeping with existing consensus guidelines.

This phase 1 study evaluated frontline brentuximab vedotin in combination with cyclophosphamide, doxorubicin, and prednisone (BV+CHP; 6 cycles, then up to 10 cycles of brentuximab vedotin monotherapy) in 26 patients with CD30+ peripheral T-cell lymphoma, including 19 with systemic anaplastic large cell lymphoma. All patients (100%) achieved an objective response, with a complete remission (CR) rate of 92%; none received a consolidative stem cell transplant. After a median observation period of 59.6 months (range, 4.6-66.0) from first dose, neither the median progression-free survival (PFS) nor the median overall survival (OS) was reached. No progression or death was observed beyond 35 months. The estimated 5-year PFS and OS rates were 52% and 80%, respectively. Eighteen of 19 patients (95%) with treatment-emergent peripheral neuropathy (PN) reported resolution or improvement of symptoms. Thirteen patients (50%) remained in remission at the end of the study, with PFS ranging from 37.8+ to 66.0+ months. Eight of these 13 patients received the maximum 16 cycles of study treatment. These final results demonstrate durable remissions in 50% of patients treated with frontline BV+CHP, suggesting a potentially curative treatment option for some patients. This trial was registered at www.clinicaltrials.gov as #NCT01309789.

Introduction The phase 3 ECHELON-2 study (NCT01777152) compared frontline treatment with brentuximab vedotin plus cyclophosphamide, doxorubicin, and prednisone (A+CHP) to cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) for patients (pts) with systemic anaplastic large cell lymphoma (sALCL) or other CD30+ peripheral T-cell lymphomas (PTCL). At 5 years, A+CHP continues to provide clinically meaningful improvement in progression-free survival (PFS) (hazard ratio [HR] 0.70 [95% confidence interval {CI}: 0.53, 0.91], P=0.0077) and overall survival (OS) (HR 0.72 [95% CI: 0.53, 0.99], P=0.0424) vs CHOP. Ongoing remission was observed in ~60% of pts with sALCL, with a manageable safety profile, including continued resolution or improvement of peripheral neuropathy (Horwitz S, et al. ASH 2020). Due to the rarity of this disease and lack of data on prospective, uniformly treated pts, ECHELON-2 provides a large and unique prospective data set with potential utility in informing future studies of PTCL. Herein, we report a series of exploratory analyses in prespecified subgroups based on age, gender, and histology to supplement the data from the full 5-year analysis. Methods ECHELON-2 (N=452) is a randomized, double-blind, double-dummy, placebo-controlled, multicenter study. Eligible pts with previously untreated CD30+ PTCL were randomized 1:1 to A+CHP or CHOP for 6 or 8 cycles. Randomization was stratified by histological subtype and international prognostic index (IPI) score. The primary endpoint of PFS was assessed per blinded independent central review in the primary analysis and per investigator in this exploratory subgroup analysis. Outcomes by age Results Among all pts The potential association of gender with PFS outcomes varied within each treatment arm: males on the CHOP arm had higher PFS than females while females had higher PFS than males on the A+CHP arm (Table 2). In addition, the OS benefit of A+CHP vs CHOP was consistent for both genders (female, HR 0.68 [95% CI: 0.40, 1.16], P=0.1597; male, HR 0.73 [95% CI: 0.49, 1.08], P=0.1148). Females and males had similar OS within each arm (A+CHP, female vs male: HR 1.00 [95% CI: 0.61, 1.64], P=0.9966; CHOP, female vs male: HR 1.03 [95% CI: 0.66, 1.60], P=0. 9054). Among all pts with PTCL-NOS, the median PFS and OS were 13.57 months and 46.4 months. When assessing by treatment arm, the PFS (Table 1) and OS (HR 0.75 [95% CI: 0.37, 1.48], P=0.4003) HRs were similar to the intent-to-treat (ITT) population. Among all pts with AITL, the median PFS was 23.75 months and the median OS was not reached. When assessing by treatment arm, the PFS (Table 1) favored CHOP and OS was similar (HR 1.01 [95% CI: 0.40, 2.55], P=0.9855). In the sALCL subgroup, PFS was superior in those treated with A+CHP overall and across IPI subgroups: 0-1, 2-3, 4-5 (Table 1). OS was also longer in the A+CHP arm (HR 0.66 [95% CI: 0.43, 1.01], P=0.0529) overall and across IPI subgroups: 0-1 (HR 0.73 [95% CI: 0.20, 2.73], P=0.6411), 2-3 (HR 0.57 [95% CI: 0.32, 1.01], P=0.0496), and 4-5 (HR 0.89 [95% CI: 0.42, 1.89], P=0.7606). Conclusions ECHELON-2 results at 5 years demonstrate a generally consistent benefit of A+CHP over CHOP across subgroups and for the ITT population. Furthermore, this large prospective dataset of pts with PTCL has redefined efficacy outcomes for this population and provides important benchmark data to inform future studies. Figure 1 Figure 1. Disclosures Horwitz: Affimed: Research Funding; Acrotech Biopharma, Affimed, ADC Therapeutics, Astex, Merck, Portola Pharma, C4 Therapeutics, Celgene, Janssen, Kura Oncology, Kyowa Hakko Kirin, Myeloid Therapeutics, ONO Pharmaceuticals, Seattle Genetics, Shoreline Biosciences, Inc, Takeda, Trillium Th: Consultancy; ADC Therapeutics, Affimed, Aileron, Celgene, Daiichi Sankyo, Forty Seven, Inc., Kyowa Hakko Kirin, Millennium /Takeda, Seattle Genetics, Trillium Therapeutics, and Verastem/SecuraBio.: Consultancy, Research Funding; Aileron: Research Funding; Celgene: Research Funding; C4 Therapeutics: Consultancy; Crispr Therapeutics: Research Funding; Daiichi Sankyo: Research Funding; Forty Seven, Inc.: Research Funding; Kura Oncology: Consultancy; Kyowa Hakko Kirin: Consultancy, Research Funding; Millennium/Takeda: Research Funding; Myeloid Therapeutics: Consultancy; ONO Pharmaceuticals: Consultancy; Seattle Genetics: Consultancy, Research Funding; Secura Bio: Consultancy; Shoreline Biosciences, Inc.: Consultancy; Takeda: Consultancy; Trillium Therapeutics: Consultancy, Research Funding; Tubulis: Consultancy; Verastem/Securabio: Research Funding. Savage: Astra-Zeneca: Consultancy, Honoraria; Servier: Consultancy, Honoraria; Takeda: Other: Institutional clinical trial funding; AbbVie: Consultancy, Honoraria; Merck: Consultancy, Honoraria, Other: Institutional clinical trial funding; BMS: Consultancy, Honoraria, Other: Institutional clinical trial funding; Seattle Genetics: Consultancy, Honoraria; Roche: Research Funding; Beigene: Other: Institutional clinical trial funding; Genentech: Research Funding. Illidge: Seagen Inc.: Research Funding. Advani: Astellas/Agensys: Research Funding; AstraZeneca: Membership on an entity's Board of Directors or advisory committees; Bayer: Membership on an entity's Board of Directors or advisory committees; Bristol Myer Squibb: Membership on an entity's Board of Directors or advisory committees; Cell Medica: Membership on an entity's Board of Directors or advisory committees; Forty Seven: Membership on an entity's Board of Directors or advisory committees, Research Funding; Genetech Inc.: Membership on an entity's Board of Directors or advisory committees, Research Funding; Gilead: Membership on an entity's Board of Directors or advisory committees; Janssen Pharmaceutical: Research Funding; Juno: Membership on an entity's Board of Directors or advisory committees; Kite Pharma: Membership on an entity's Board of Directors or advisory committees; Kura: Research Funding; Kyowa: Membership on an entity's Board of Directors or advisory committees; Merck: Research Funding; Millenium: Research Funding; Pharmacyclics: Consultancy, Research Funding; Portola Pharmaceuticals: Consultancy; Regeneron: Research Funding; Roche: Membership on an entity's Board of Directors or advisory committees; Sanofi: Membership on an entity's Board of Directors or advisory committees; Seattle Genetics: Research Funding; Takeda: Membership on an entity's Board of Directors or advisory committees. Shustov: Seagen Inc.: Research Funding. Bartlett: Pharmacyclics: Research Funding; Millennium: Research Funding; Merck: Research Funding; Kite, a Gilead Company: Research Funding; Janssen: Research Funding; Genentech: Research Funding; Forty Seven: Research Funding; Celgene: Research Funding; Bristol Myers Squibb: Research Funding; Autolus: Research Funding; Seagen: Consultancy, Research Funding; Roche/Genentech: Consultancy; ADC Therapeutics: Consultancy, Research Funding. Jacobsen: Takeda: Consultancy; Syros: Consultancy; Janssen: Research Funding; Novartis: Research Funding; Pharmacyclics: Research Funding; Acerta: Research Funding. Koch: Seagen Inc.: Research Funding. Eva: Takeda: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Fanale: Seagen, Inc: Current Employment, Current equity holder in publicly-traded company. Fenton: Seagen Inc.: Current Employment, Current equity holder in publicly-traded company. Campana: Seagen Inc.: Research Funding. Dong: Seagen Inc.: Research Funding. Truemper: Seagen Inc.: Research Funding.

Introduction ABVD (doxorubicin, bleomycin, vinblastine, and dacarbazine) represents standard frontline therapy for classical Hodgkin lymphoma (CHL) in North America. Substituting brentuximab vedotin for bleomycin in this regimen demonstrated improved efficacy in advanced stage patients (pts) but also increased toxicity (Connors et al NEJM 2017). PD-1 inhibitors are highly active in relapsed/refractory CHL, and the first-line setting may represent the ideal time for incorporating PD1 inhibition given the relatively intact host immunity and juxtaposition of malignant cells with T cells in the tumor microenvironment. Methods This was a single arm pilot study combining pembrolizumab with AVD in untreated CHL of any stage. Eligibility requiredECOG 0-1, adequate organ function, and measurable disease. The trial intended to enroll 30 pts. AVD was given at standard doses on days 1 and 15 of a 28-day cycle. Pembrolizumab (200 mg IV) was given starting cycle 1 day 1 and every 21 days thereafter (cycle 1 day 22, cycle 2 day 15 etc.). The primary objective was to estimate the safety of delivering 2 cycles of APVD. The secondary objective was to estimate the FDG-PET2 negative (Deauville score 1-3) rate after 2 cycles of APVD. Exploratory objectives included overall and progression free survival, predictive capacity of PET2 after APVD, analysis of ctDNA as well as assessments of metabolic tumor volume. After PET2 response assessment, subjects could continue APVD for up to 6 total cycles as deemed appropriate for their stage/risk factors (including alternate systemic therapy or radiotherapy). Results All 30 subjects have enrolled and received at least 2 cycles of therapy. Median age was 32 years (range 18-69). Most pts had advanced stage (stage I n =1 (3%), stage II n=11 (37%), stage III n=7 (23%), stage IV n=11, (37%)). Thirteen (43%) pts had B symptoms at diagnosis and 5 (17%) had bulky disease. Among the 30 pts enrolled, 28 are evaluable for response (one pt declined interim-PET and further treatment and final patient will have PET2 shortly after abstract deadline.Nineteen (68%) pts were PET2 neg (5PS 1-3). No PET2+ pts have progressed to date. End of therapy (EOT) PET negativity (after 2-6 cycles) was 78% (18/23). Among the 5 pts with residual FDG uptake at EOT, only 1 (20%) has developed recurrent lymphoma. With median follow-up of 10.3 months, 1-year PFS and OS were 96% and 100%, respectively. Six (20%) pts required interruption of pembrolizumab due to toxicity, primarily grade ≥ 2 transaminitis (83%). Those with grade 2 transaminitis (2/6) completed chemotherapy prior to resolving to grade 1 and did not receive additional pembrolizumab. Those with grade ≥ 3 transaminitis (3/6) were required to permanently discontinue pembrolizumab. All transaminitis was transient and resolved with steroids and/or withholding pembrolizumab. No pneumonitis and no other grade ≥ 3 immune-related AEs were observed. Toxicities were otherwise similar to those expected with ABVD chemotherapy. No pt had a treatment delay of > 21 days during the first 2 cycles, and no pt who interrupted pembrolizumab due to toxicity has relapsed. Updated efficacy and more detailed safety data will be presented at the meeting. Conclusion Pembrolizumab + AVD without a PD-1 lead-in is safe and effective therapy for frontline HL. In this study, PET2+ following APVD does not appear to be associated with high risk of disease relapse. Additional analyses of MTV and ctDNA are ongoing to better understand these results. Concurrent APVD, without an anti-PD-1 run-in, represents a well-tolerated, and efficacious backbone that can be further evaluated in all stages of CHL. Figure 1 Figure 1. Disclosures Lynch: Incyte: Research Funding; TG Therapeutics: Research Funding; Cyteir: Research Funding; Genentech: Research Funding; SeaGen: Research Funding; Bayer: Research Funding; Juno Therapetics: Research Funding; Morphosys: Consultancy. Ujjani: ACDT: Honoraria; Kite, a Gilead Company: Honoraria; Gilead: Honoraria; TG Therapeutics: Honoraria; Janssen: Consultancy; Epizyme: Consultancy, Membership on an entity's Board of Directors or advisory committees; Atara Bio: Consultancy; Loxo: Research Funding; Adaptive Biotechnologies: Research Funding; AstraZeneca: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; AbbVie: Consultancy, Research Funding; Pharmacyclics: Consultancy, Research Funding. Poh: Acrotech: Honoraria; Incyte: Research Funding; Morphosys: Consultancy. Smith: Incyte Corporation: Research Funding; Merck Sharp & Dohme Corp: Research Funding; Ignyta (spouse): Research Funding; Acerta Pharma BV: Research Funding; Portola Pharmaceuticals: Research Funding; ADC Therapeutics: Consultancy; Karyopharm: Consultancy; Ayala (spouse): Research Funding; De Novo Biopharma: Research Funding; KITE pharm: Consultancy; Genentech: Research Funding; AstraZeneca: Consultancy, Research Funding; Bristol Myers Squibb (spouse): Research Funding; Incyte: Consultancy; Bayer: Research Funding; Beigene: Consultancy, Research Funding; Millenium/Takeda: Consultancy. Shadman: Mustang Bio, Celgene, Bristol Myers Squibb, Pharmacyclics, Gilead, Genentech, Abbvie, TG Therapeutics, Beigene, AstraZeneca, Sunesis, Atara Biotherapeutics, GenMab: Research Funding; Abbvie, Genentech, AstraZeneca, Sound Biologics, Pharmacyclics, Beigene, Bristol Myers Squibb, Morphosys, TG Therapeutics, Innate Pharma, Kite Pharma, Adaptive Biotechnologies, Epizyme, Eli Lilly, Adaptimmune , Mustang Bio and Atara Biotherapeutics: Consultancy. Shustov: Seagen Inc.: Research Funding. Till: Mustang Bio: Consultancy, Patents & Royalties, Research Funding. Alizadeh: Gilead: Consultancy; Janssen Oncology: Honoraria; Roche: Consultancy, Honoraria; Celgene: Consultancy, Research Funding; Foresight Diagnostics: Consultancy, Current holder of individual stocks in a privately-held company, Current holder of stock options in a privately-held company; Bristol Myers Squibb: Research Funding; Forty Seven: Current holder of individual stocks in a privately-held company, Current holder of stock options in a privately-held company; CAPP Medical: Current holder of individual stocks in a privately-held company, Current holder of stock options in a privately-held company; Cibermed: Consultancy, Current holder of individual stocks in a privately-held company, Current holder of stock options in a privately-held company. Gopal: Epizyme: Consultancy, Honoraria; MorphoSys: Honoraria; Gilead: Consultancy, Honoraria, Research Funding; I-Mab bio: Consultancy, Honoraria, Research Funding; Genetech: Consultancy, Honoraria, Research Funding; Teva: Research Funding; Beigene: Consultancy, Honoraria; SeaGen: Consultancy, Honoraria, Research Funding; Incyte: Honoraria; Acrotech: Consultancy, Honoraria; Cellectar: Consultancy, Honoraria; Nurix Inc: Consultancy, Honoraria; ADC Therapeutics: Consultancy, Honoraria; Servier: Consultancy, Honoraria; Merck: Consultancy, Honoraria, Research Funding; Takeda: Research Funding; Astra-Zeneca: Research Funding; Agios: Research Funding; Bristol Meyers Squibb: Research Funding; Karyopharm: Consultancy, Honoraria; Janssen: Consultancy, Honoraria, Research Funding; IGM Biosciences: Research Funding; Kite: Consultancy, Honoraria.

BACKGROUND: Novel agents added to front-line treatments for adult ALL yield high rates of measurable residual disease (MRD) negativity and survival. However, these approaches are infeasible outside large centers and in lower-resource settings. HyperCVAD is commonly used regardless of Philadelphia chromosome (Ph) status but has limitations, particularly in older patients (pts). Because of its efficacy for high-grade lymphomas (NEJM 2013, p. 1915), we hypothesized that DA-EPOCH would be active and safe in adult ALL. METHODS: Details of this study have been reported (ASH 2018, #1519; NCT03023046). Adults with newly-diagnosed ALL were eligible if not candidates for pediatric-inspired therapy (ie, Ph+, age ≥ 40). DA-EPOCH was given with G-CSF (Blood 2002, p. 2685). After treatment of the 1 st 5 pts, the dose-adjustment paradigm was employed once cytopenias were not due to ALL, typically after cycle 2. If Ph+, imatinib (IM) 600 mg or dasatinib (DAS) 100 mg daily on Days 1-14 of each cycle was added. If CD20+, rituximab 375 mg/m 2 was given once per cycle regardless of Ph status. Up to 8 cycles could be given followed by maintenance (POMP ± TKI) or allogeneic transplant (HCT). Pts with WBC > 30K/µL or LDH > 3x upper limit of normal at diagnosis received 10 doses of intrathecal methotrexate as CNS prophylaxis, and others received 8. Response was determined by bone marrow aspirate morphology (morph), multiparameter flow cytometry (MFC) and (for Ph+) BCR-ABL RT-PCR, with complete molecular response (CMR) assigned when the latter was undetectable. When MRD- by MFC (MFC-) per EuroFlow criteria (Leukemia 2010, p. 521), high-throughput sequencing-based MRD testing (HTS; ClonoSEQ) was performed. IKZF1plus was identified by chromosomal microarray as defined previously (JCO 2018, p. 1240). The primary endpoint was rate of MFC- remission within 4 cycles of therapy. Based on an institutional historical rate of MFC- after ≤ 4 cycles of 50% with hyperCVAD + TKI for Ph+ ALL (Am J Hematol 2018, p. 546), we defined success if we observed such remissions in ≥ 70%. A Simon 2-stage design with α = 0.09 and 80% power led to a sample size of 28 pts and success if ≥ 18 were MFC- after ≤ 4 cycles. For Ph-, we enrolled in cohorts (up to 25 total pts) if the upper bound of a 90% confidence interval (CI) stayed ≥ 59%, our historical rate with hyperCVAD. Follow-up provided to 7/1/21. RESULTS: 53/54 enrolled pts were evaluable. Baseline characteristics are in Table 1 and response rates in Table 2. For Ph+ ALL, 20 of 28 pts (71%; 90% CI = 54-85%) reached MFC- after ≤ 4 cycles; TKI used was DAS for 23 pts and IM for 5 pts. In Ph- ALL, 16 of 25 pts (64%; 90% CI = 46-80%) were MFC- after ≤ 4 cycles. Median follow-up of survivors was 22 months (mo; range: 4-50 mo). Median and 2-yr EFS were 15 mo and 32% (respectively); median OS was not reached, and 2-yr OS was 70% (Figure). In those age > 60 yrs, 2-yr EFS was 49% and OS was 71%. In univariate Cox models, neither WBC, age, adverse-risk cytogenetics, IKZF1plus, nor MFC- after ≤ 4 cycles were significantly associated with EFS or OS; the strongest was high-risk WBC with EFS (hazard ratio 2.1, p = 0.068). In sum, 36 pts reached MFC-: relapse occurred in 12 of 23 pts (52%) given maintenance therapy vs 4 of 12 pts (33%) who received HCT (p = 0.48 by Fisher exact test). Of 18 pts without MRD by HTS, 9 (50%) relapsed. None of the 6 pts given blinatumomab for MRD after DA-EPOCH have relapsed. Four pts (8%) had isolated CNS relapse. 44 pts (83%) developed ≥ 1 Grade (Gr) 3+ non-hematologic (heme) AE related to DA-EPOCH, with a mean of 2 per pt. Those seen in ≥ 10% of pts were febrile neutropenia/infection (23 Gr 3, 2 Gr 4); mucositis (7 Gr 3); and ALT increase (6 Gr 3). There was only 1 treatment-related death (2%; gastric hemorrhage). Twelve pts (23%) discontinued due to acute or cumulative toxicity. As for heme AEs in pts treated after cycle 1 (ie, when ALL was not the cause), only 15 pts (34%) had a Gr 4 platelet count at any time. CONCLUSIONS: DA-EPOCH yields comparable response and survival rates (with manageable toxicity) as more logistically-complex therapies in primarily high-risk ALL. When TKI was added for Ph+ disease, rates of MFC- exceeded the predefined threshold for success. Its efficacy and safety profile make it an appealing backbone to which novel agents may be added. Pending results of ongoing multivariable analyses comparing DA-EPOCH to historical treatments, DA-EPOCH could be considered a standard option, particularly in older adults and/or lower-resource settings. Figure 1 Figure 1. Disclosures Cassaday: Pfizer: Consultancy, Research Funding; Kite/Gilead: Consultancy, Honoraria, Research Funding; Amgen: Consultancy, Research Funding; Pepromene Bio: Membership on an entity's Board of Directors or advisory committees; Servier: Research Funding; Merck: Research Funding; Vanda Pharmaceuticals: Research Funding. Percival: Abbvie: Research Funding; Nohla Therapeutics: Research Funding; Cardiff Oncology: Research Funding; Glycomimetics: Research Funding; Biosight: Research Funding; BMS/Celgene: Research Funding; Pfizer: Research Funding; Oscotec: Research Funding; Trillium: Research Funding. Halpern: Gilead: Research Funding; Abbvie: Consultancy; Agios Pharmaceuticals: Research Funding; Tolero Pharmaceuticals: Research Funding; Novartis: Research Funding; Bayer: Research Funding; Imago Pharmaceuticals: Research Funding; Jazz Pharmaceuticals: Research Funding; Agios: Consultancy; Nohla Therapeutics: Research Funding; Pfizer: Research Funding. Becker: Glycomimetics: Research Funding; CVS Caremark: Consultancy; Abbie: Research Funding; BMS: Research Funding; Pfizer: Research Funding; Cardiff Oncology: Research Funding; SecuraBio: Research Funding. Oehler: BMS: Consultancy; OncLive: Honoraria; Takeda: Consultancy; Pfizer: Research Funding. Shustov: Seagen Inc.: Research Funding. Orozco: Actinium Pharmaceuticals, Inc.: Other: site PI for clinical trial(s) sponsored by Actinium, Research Funding. Walter: BMS: Consultancy; Astellas: Consultancy; Agios: Consultancy; Amphivena: Consultancy, Other: ownership interests; Selvita: Research Funding; Pfizer: Consultancy, Research Funding; Jazz: Research Funding; Macrogenics: Consultancy, Research Funding; Immunogen: Research Funding; Celgene: Consultancy, Research Funding; Genentech: Consultancy; Janssen: Consultancy; Kite: Consultancy; Aptevo: Consultancy, Research Funding; Amgen: Research Funding. Radich: Amgen: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees; Genentech: Membership on an entity's Board of Directors or advisory committees; BMS: Membership on an entity's Board of Directors or advisory committees. OffLabel Disclosure: Rituximab is not FDA approved for the treatment of acute lymphoblastic leukemia.

Background: Rituximab with cyclophosphamide, doxorubicin, vincristine, and prednisone (RCHOP) remains standard therapy for previously untreated diffuse large B-cell lymphoma (DLBCL). We previously reported that adding pembrolizumab to RCHOP (PR-CHOP), shows no significant additive toxicity and a promising 2-year progression free survival of 83% (Smith B J Haem 2019), with no progression events among 19 pts with known PDL-1+ tumors. In that analysis, we noted 83% of patients had tumor PDL-1 expression by IHC using a centralized standard assay, including 18/23 (78%) and 13/23 (56%) demonstrating positivity in ≥5% and ≥30% of lymphoma cells respectively. Herein we report long-term clinical follow up, as well as results of high-resolution molecular karyotyping using chromosome genomic array testing (CGAT), to assess whether 9p24.1 abnormalities explained the extent of PDL1 tumor expression. Methods: Pts age 18 years or older with previously untreated DLBCL, transformed lymphoma and grade 3 B follicular lymphoma eligible for 6-cycle, curative-intent RCHOP were eligible. Steroids within 7 days of treatment, active autoimmune disease, or history of pneumonitis were excluded. This phase I study combined pembrolizumab (200 mg IV q 3 weeks x 6) to RCHOP x 6, with supportive care per standard practice. There was no maintenance or consolidation therapy. Baseline PDL1 expression was analyzed centrally (Merck/Qualtek). CGAT was performed from DNA extracted from formalin-fixed, paraffin-embedded tissue sections using the OncoScan platform (ThermoFisher). H&E slides of adjacent sections of the tissue used for CGAT were evaluated by a pathologist to ensure a minimum of 30% tumor content. Patients were followed for relapse and survival. Results: Among 30 treated pts with a median follow up of 32 months, there have been no additional DLBCL relapses or deaths since the published report. There has been one relapse of follicular lymphoma in a patient with initial composite lymphoma , who is now in remission 1 year after autologous stem cell transplantation. 3-year estimated PFS is 83% and OS is 86%. On univariate analysis, only tumor bulk 7.5 cm or greater (p=.02) and absence tumor PDL-1 expression by IHC (p=.001) predicted inferior PFS. Tumor bulk, (p=.03), IPI 3 or higher (p=.01), and absence of tumor PDL-1 expression (p=.001) predicted worse overall survival. PFS and OS were unaffected by cell of origin by IHC, double expresser status, or diagnosis to treatment interval greater than median (29 days). Regarding safety, there were late cases of paraneoplastic pemphigus and rheumatoid arthritis 5 and 8 months from last dose of pembrolizumab, respectively. Both of these were managed successfully with immunosuppression. Chromosome genomic array testing CGAT) was performed to assess copy number aberrations (CNAs) and copy neutral loss of heterozygosity (cnLOH), particularly for the presence of gains or amplifications involving locus 9p24.1, containing the CD274 (PDL1) gene. Of 15 tested pretreatment baseline diagnostic tissue specimens, 14 provided informative result with 12 abnormal and 2 normal. Notably, no gain or amplification in 9p24.1 were seen; there was one case of deletion and 1 with cnLOH. The percent genome altered among abnormal cases ranged from 2% to 37% (median 12%). Complex karyotype, defined as genomic aberrations involving at least 3 chromosome arms (or % genome altered greater than 5% by CGAT), was seen in 10/14 pts (71%). This 14-sample data set included 6/14 pts with >30% PDL1 tumor expression (and 10 with 5% or greater PDL1-tumor expression). Conclusions: No additional safety signals have been observed, and PFS/OS remain favorable for the combination of pembrolizumab + RCHOP in this single arm trial with the best results in PDL-1+ disease. Despite frequent tumor PDL1-expression at baseline, no gains or implications of 9p24.1 were observed suggesting alternative mechanisms for overexpression of PDL-1. Further study this regimen and others testing combinations of immune checkpoint inhibition with first-line DLBCL therapy are warranted, to better ascertain the potential superiority of this strategy in this setting. Disclosures Smith: Portola: Research Funding; Incyte: Research Funding; Ignyta: Research Funding; Genentech: Research Funding; AstraZeneca: Research Funding; Acerta Pharma BV: Research Funding; Karyopharm: Consultancy; Beigene: Consultancy; Seattle Genetics: Research Funding; AstraZeneca: Consultancy; Millenium/Takeda: Consultancy; Pharmacyclics: Research Funding; Merck: Research Funding; De Novo Biopharma: Research Funding; Bayer: Research Funding; Ayala: Research Funding; Bristol Meyers Squibb: Research Funding. Fromm:Merck: Research Funding. Till:Mustang: Patents & Royalties, Research Funding. Shadman:Mustang Bio, Celgene, Pharmacyclics, Gilead, Genentech, Abbvie, TG therapeutics, Beigene, Astra Zeneca, Sunesis, Beigene: Research Funding; Abbvie, Genentech, Astra Zeneca, Sound Biologics , Pharmacyclics, Verastem, ADC therapeutics, Beigene, Cellectar, BMS, Morphosys and Atara Biotherapeutics: Consultancy. Lynch:Bayer: Research Funding; Rhizen Pharmaceuticals: Research Funding; Incyte: Research Funding; TG Therapeutics: Research Funding; Takeda: Research Funding; Juno Therpeutics: Research Funding; MorphoSys: Consultancy; Genentech: Research Funding; Cyteir: Research Funding. Cowan:Janssen: Consultancy, Research Funding; Bristol Myers Squibb: Research Funding; Sanofi: Consultancy; Cellectar: Consultancy; Abbvie: Research Funding. Ujjani:Gilead/Kite: Consultancy, Research Funding; Atara: Consultancy, Honoraria; Genentech: Consultancy, Honoraria; MorphoSys: Consultancy; Verastem Oncology: Consultancy, Honoraria; Abbvie: Consultancy, Honoraria, Research Funding; AstraZeneca: Consultancy, Honoraria, Research Funding. Shustov:Seattle Genetics: Research Funding. Cassaday:Vanda Pharmaceuticals: Research Funding; Seattle Genetics: Current Employment, Current equity holder in publicly-traded company; Merck: Research Funding; Pfizer: Honoraria, Research Funding; Amgen: Consultancy, Research Funding; Kite/Gilead: Consultancy, Research Funding. Gopal:Seattle Genetics; Janssen; Takeda; IgM Bio; IMab Bio; BMS; Astra Zeneca; Merck; Gilead: Research Funding; Seattle Genetics; Janssen; IMab Bio; TG Therapeutics; Astra Zeneca; Merck; Gilead; ADC Therapeutics; Nurix; TG therapeutics, Cellectar; Actinium: Consultancy; IgM bio, BMS, merck: Research Funding; imab bio, takeda,astrazeneca,gilead: Research Funding.

Background: Ibrutinib (I) and venetoclax (V) have each demonstrated modest single-agent activity in relapsed/refractory follicular lymphoma (FL) (Gopal A, JCO 2018; Davids M, JCO 2017). Preclinical data have shown synergy with these agents in B-cell cell lines (Kuo H, Mol Cancer Ther 2017). Based on these observations, we proposed the first trial to combine I and V in FL. Results from the phase Ib portion of this multi-institutional investigator-initiated trial are presented here (NCT02956382). Methods: This phase Ib/II trial is open at Georgetown/Lombardi CCC, Hackensack/John Theurer CC, and University of Washington/Fred Hutchinson/Seattle Cancer Care Alliance. Eligibility criteria include WHO grade 1-3a FL, >1 prior systemic therapy, measurable disease warranting therapy by standard criteria or physician discretion, ECOG performance status < 2, adequate marrow, hepatic, renal function. Patients (pts) were enrolled in a standard phase I 3+3 design at a starting dose level (DL) of I 420 mg daily, V 400 mg daily (DL0). The highest initially planned dose level was DL3: I 560 mg daily, V 800 mg daily. There was no dose ramp up of V based on monotherapy experience in FL. Pts at high risk for tumor lysis syndrome (TLS), defined as node ≥ 8 cm and/or significant lymphocytosis, were hospitalized for initial dose. Pts received study drugs until progression or unacceptable toxicity. Response was assessed by PET-CT and bone marrow biopsy (if marrow involvement present at time of enrollment). Results: Sixteen pts were enrolled between November 2017 - May 2020. Median age was 66 years (range 50-87); 75% were male; 75% were Stage III/IV, 94% had WHO grade 1/2 FL (Table 1). FLIPI score at enrollment was 25% low risk, 44% intermediate risk, 31% high risk. Two pts were considered high risk for TLS. Pts received a median of 2 prior therapies (range 1-8); 19% were refractory to last line of therapy. Cohort enrollment was: DL0 (n=3), DL1 (n=6), DL2 (n=6), DL3 (n=1). The protocol was amended to close DL3 based on pharmacokinetic data from DL2 indicating a 1.8-fold higher mean steady-state ibrutinib plasma exposure compared to ibrutinib 560 mg monotherapy and concern for potential toxicity. Grade 3 adverse events (AE) included neutropenia (25%), thrombocytopenia (13%), lung infection (13%), upper respiratory infection (6%), neutropenic fever (6%), atrial fibrillation (6%), ALT/AST elevations (6%), mucositis (6%), failure to thrive in setting of progression (6%), abdominal pain (6%). There were no grade 4/5 AE. Grade 1/2 AE occurring in > 20% of pts included diarrhea (75%), nausea (63%), bruising (38%), rash (31%), headache (31%), constipation (25%), fatigue (25%). There was no evidence of clinical TLS; 19% had grade 1 hyperuricemia. The pt enrolled at DL3 had grade 1 diarrhea, grade 1 neutropenia. One dose limiting toxicity (DLT) occurred at DL1 (I 560 mg, V 400 mg): grade 3 neutropenia with fever and infection. There were no other DLTs. Therefore, DL2 (I 560 mg, V 600 mg) was determined to be the recommended phase 2 dose (RP2D). The ORR was 69% (0.413, 0.890); CR 25% (0.073, 0.524). The ORR at the RP2D was 83% (CR 33%). Responses by dose level are listed in Table 2. The regimen demonstrated activity in the bone marrow; 2 pts had eradication of involvement and 1 had a decrease from 60% to 0.5% by flow cytometry. Response by lines of prior therapy: 1 (86%, 6/7), > 2 (56%, 5/9). Most pts (91%) had a response by time of first assessment (12 weeks). The median progression-free survival (PFS) was 8.3 months (5.6 months, NA) (Figure 1). Of note, 2 responding pts chose to withdraw from study due to travel and were censored in the PFS analysis at time of discontinuation. One remained in a CR at least 9 months after study withdrawal as documented by PET-CT performed off protocol. No pts discontinued due to toxicity. Conclusion: In the first clinical trial to combine a BTK inhibitor and a BCL-2 inhibitor in relapsed/refractory FL, we found the I-V doublet to demonstrate a toxicity profile similar to that seen in mantle cell lymphoma and CLL. While our sample size is small, there was no evidence of clinical TLS, despite omission of the V ramp up. Preliminary results of anti-tumor activity are encouraging and further evaluation at the RP2D (I 560 mg, V 600 mg) is ongoing in the phase II trial. The combination of ibrutinib and venetoclax may provide an effective option for FL, utilizing a targeted approach distinct from other novel agents currently approved for this malignancy. Disclosures Ujjani: Verastem Oncology: Consultancy, Honoraria; Genentech: Consultancy, Honoraria; MorphoSys: Consultancy; Atara: Consultancy, Honoraria; AstraZeneca: Consultancy, Honoraria, Research Funding; Abbvie: Consultancy, Honoraria, Research Funding; Gilead/Kite: Consultancy, Research Funding. Lai:Agios: Consultancy; Macrogenics: Consultancy; Astellas: Speakers Bureau; Jazz: Speakers Bureau; Abbvie: Consultancy. Leslie:Seattle Genetics: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; KitePharma: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; BMS: Speakers Bureau; Celgene: Speakers Bureau; BeiGene: Honoraria, Speakers Bureau; Pharmacyclics: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; AstraZeneca: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Epizyme: Honoraria, Speakers Bureau; Karyopharm: Honoraria, Speakers Bureau; Bayer: Consultancy, Membership on an entity's Board of Directors or advisory committees; ADC therapeutics: Consultancy, Membership on an entity's Board of Directors or advisory committees; AbbVie: Consultancy, Membership on an entity's Board of Directors or advisory committees; TG Therapeutics: Consultancy, Membership on an entity's Board of Directors or advisory committees. Broome:sanofi: Honoraria; argenx: Honoraria; apellis: Honoraria; Alexion: Honoraria. Gopal:IgM bio, BMS, merck: Research Funding; imab bio, takeda,astrazeneca,gilead: Research Funding; Seattle Genetics; Janssen; IMab Bio; TG Therapeutics; Astra Zeneca; Merck; Gilead; ADC Therapeutics; Nurix; TG therapeutics, Cellectar; Actinium: Consultancy; Seattle Genetics; Janssen; Takeda; IgM Bio; IMab Bio; BMS; Astra Zeneca; Merck; Gilead: Research Funding. Smith:Beigene: Consultancy; Millenium/Takeda: Consultancy; AstraZeneca: Consultancy; Portola: Research Funding; Seattle Genetics: Research Funding; Pharmacyclics: Research Funding; Merck: Research Funding; Incyte: Research Funding; Ignyta: Research Funding; Genentech: Research Funding; De Novo Biopharma: Research Funding; Bristol Meyers Squibb: Research Funding; Ayala: Research Funding; Acerta Pharma BV: Research Funding; AstraZeneca: Research Funding; Bayer: Research Funding; Karyopharm: Consultancy. Till:Mustang: Patents & Royalties, Research Funding. Lynch:Morphosys: Consultancy; Takeda: Research Funding; Bayer: Research Funding; TG therapeutics: Research Funding; Incyte: Research Funding; Juno: Research Funding; Cyteir: Research Funding; Genentech: Research Funding; Rhizen: Research Funding. Shadman:Genentech: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; TG therapeutics: Research Funding; Celgene: Research Funding; Sunesis: Research Funding; Gilead: Research Funding; AstraZeneca: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Bristol Meyers Squibb: Consultancy, Membership on an entity's Board of Directors or advisory committees; Verastem: Consultancy, Membership on an entity's Board of Directors or advisory committees; ADC Therapeutics: Consultancy, Membership on an entity's Board of Directors or advisory committees; Atara Biotherapeutics: Consultancy, Membership on an entity's Board of Directors or advisory committees; AbbVie: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Cellectar: Consultancy, Membership on an entity's Board of Directors or advisory committees; Pharmacyclics: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Mustang Bio: Research Funding; BeiGene: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Acerta Pharma: Ended employment in the past 24 months; MophoSys: Consultancy, Membership on an entity's Board of Directors or advisory committees; Sound Biologics: Consultancy, Membership on an entity's Board of Directors or advisory committees. Maloney:Novartis: Consultancy, Honoraria; Bioline Rx: Consultancy, Honoraria; Juno Therapeutics: Consultancy, Honoraria, Patents & Royalties: Patents are pending, but not issued, licensed, no royalties, no licensees., Research Funding; A2 Biotherapeutics: Consultancy, Current equity holder in publicly-traded company, Honoraria; Celgene: Consultancy, Honoraria, Research Funding; Kite, a Gilead Company: Consultancy, Honoraria, Research Funding; Gilead Sciences: Consultancy, Honoraria; Amgen: Consultancy, Honoraria; MorphoSys: Consultancy, Honoraria; Genentech: Consultancy, Honoraria; Pharmacyclics: Consultancy, Honoraria. Cheson:TG Therapeutics: Speakers Bureau; Symbio: Membership on an entity's Board of Directors or advisory committees; Kite: Consultancy; Karyopharm: Consultancy, Membership on an entity's Board of Directors or advisory committees; Morphosys: Consultancy; Trillium: Research Funding; Abbvie: Consultancy, Research Funding; Jannsen: Consultancy; Pharmacyclics: Consultancy, Research Funding; Parexel: Consultancy; GSK: Membership on an entity's Board of Directors or advisory committees. OffLabel Disclosure: We are presenting data regarding the use of venetoclax and ibrutinib in follicular lymphoma.

This study evaluated the safety, antitumor activity, pharmacokinetics, and pharmacodynamics of inotuzumab ozogamicin (InO) for CD22-positive relapsed/refractory acute lymphoblastic leukemia. In phase 1, patients received InO 1.2 (n = 3), 1.6 (n = 12), or 1.8 (n = 9) mg/m2 per cycle on days 1, 8, and 15 over a 28-day cycle (≤6 cycles). The recommended phase 2 dose (RP2D) was confirmed (expansion cohort; n = 13); safety and activity of InO were assessed in patients receiving the RP2D in phase 2 (n = 35) and in all treated patients (n = 72). The RP2D was 1.8 mg/m2 per cycle (0.8 mg/m2 on day 1; 0.5 mg/m2 on days 8 and 15), with reduction to 1.6 mg/m2 per cycle after complete remission (CR) or CR with incomplete marrow recovery (CRi). Treatment-related toxicities were primarily cytopenias. Four patients experienced treatment-related venoocclusive disease/sinusoidal obstruction syndrome (VOD/SOS; 1 fatal). Two VOD/SOS events occurred during treatment without intervening transplant; of 24 patients proceeding to poststudy transplant, 2 experienced VOD/SOS after transplant. Forty-nine (68%) patients had CR/CRi, with 41 (84%) achieving minimal residual disease (MRD) negativity. Median progression-free survival was 3.9 (95% confidence interval, 2.9-5.4) months; median overall survival was 7.4 (5.7-9.2) months for all treated patients, with median 23.7 (range, 6.8-29.8) months of follow-up for all treated patients alive at data cutoff. Achievement of MRD negativity was associated with higher InO exposure. InO was well tolerated and demonstrated high single-agent activity and MRD-negativity rates. This trial was registered at www.clinicaltrials.gov as #NCT01363297.

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.

Background: An international survey we recently conducted indicated that, even today, adults with acute myeloid leukemia (AML) standardly remain hospitalized after completion of induction chemotherapy until resolution of cytopenias due to a high risk of infection and frequent need for transfusions. In contrast, over the last five years at our institution, hospital discharge immediately following completion of induction chemotherapy has become routine after a phase 2 trial evaluating an Early Hospital Discharge (EHD) strategy showed this approach to be safe and cost-effective. On the other hand, EHD is a nearly-universal practice following post-remission or "consolidation" therapy. Here, we sought to compare safety and healthcare resource utilization outcomes for patients who are discharged to the outpatient setting following intensive induction vs. consolidation chemotherapy. Methods: We retrospectively identified all adults aged ≥18 years with newly-diagnosed AML/high-grade myeloid neoplasms (≥10% blasts in peripheral blood/ bone marrow) who started AML-like intensive induction or consolidation chemotherapy ("7+3," high-dose cytarabine [HiDAC], or a regimen of similar/higher intensity) at our institution from 8/1/14 (completion of our phase 2 EHD study) to 7/31/18. EHD was defined as discharge from the hospital within 72 hours of completing chemotherapy (as done in our phase 2 study). Induction therapy was defined as the first course of intensive chemotherapy for untreated disease. Consolidation therapy was defined as intensive therapy if the marrow (and hematologic parameters) prior to starting treatment showed complete remission by standard International Working Group criteria. Patients with relapsed or primary refractory disease were excluded from this analysis. The study period began on the day of initial discharge and ended with count recovery, death, receipt of additional disease-directed therapy, transfer of care, or once 42 days elapsed. We collected baseline demographic and clinical characteristics, logistical information, and treatment regimen. Outcomes of interest including readmission timing/reasons, intensive care unit (ICU) admission, resource utilization (number of lab visits, provider visits, days of IV antimicrobial use, units of transfused red blood cell [RBC] and platelets) and survival. All analyses accounted for correlation between patients because 100 patients were in both the induction and consolidation datasets and 62 patients had more than 1 consolidation cycle in the dataset. Results: We identified 215 induction cycles and 225 consolidation cycles that met our criteria for EHD. As detailed in Table 1, induction EHD patients had worse baseline performance status and higher white blood cell counts than consolidation EHD patients. Consolidation patients spent more time on study (27.8 vs. 24.7 days) and spent a higher proportion of their study time as outpatients (mean of 79% vs. 71% of study time; p Conclusion: Although the early death rate, as would be expected given a baseline sicker population, was higher for EHD patients following induction compared to consolidation chemotherapy, there were no differences between the two groups in requirements for ICU care, laboratory monitoring, or transfusion need in the outpatient setting. This suggests that an EHD strategy following induction therapy may be safely and reasonably implemented at centers with infrastructure supporting EHD following standard consolidation therapy. Disclosures Halpern: Pfizer Pharmaceuticals: Research Funding; Bayer Pharmaceuticals: Research Funding. Othus:Glycomimetics: Other: Data Safety and Monitoring Committee; Celgene: Other: Data Safety and Monitoring Committee. Buckley:CTI BioPharma: Employment, Equity Ownership. Percival:Pfizer Inc.: Research Funding; Nohla Therapeutics: Research Funding; Genentech: Membership on an entity's Board of Directors or advisory committees. Becker:The France Foundation: Honoraria; AbbVie, Amgen, Bristol-Myers Squibb, Glycomimetics, Invivoscribe, JW Pharmaceuticals, Novartis, Trovagene: Research Funding; Accordant Health Services/Caremark: Consultancy. Scott:Novartis: Consultancy; Agios: Consultancy; Incyte: Consultancy; Celgene: Consultancy. Oehler:Pfizer Inc.: Research Funding; Blueprint Medicines: Consultancy; NCCN: Consultancy. Gernsheimer:Fuji film: Consultancy; Bioverativ: Consultancy; Dova pharmaceuticals: Consultancy; Novartis: Honoraria; Cellphire: Consultancy; Amgen: Consultancy, Honoraria; Rigel: Consultancy; Shionogi: Consultancy. Orozco:Actinium Pharmaceuticals: Research Funding. Cassaday:Amgen: Consultancy, Research Funding; Pfizer: Consultancy, Honoraria, Research Funding; Incyte: Research Funding; Kite/Gilead: Research Funding; Merck: Research Funding; Seattle Genetics: Research Funding; Seattle Genetics: Other: Spouse's disclosure: employment, stock and other ownership interests. Shustov:Seattle Genetics, Inc.: Research Funding. Hartley:Pfizer Inc.: Employment, Equity Ownership. Welch:Pfizer Inc: Employment, Equity Ownership. Walter:Agios: Consultancy; Amgen: Consultancy; Amphivena Therapeutics: Consultancy, Equity Ownership; Aptevo Therapeutics: Consultancy, Research Funding; Argenx BVBA: Consultancy; Astellas: Consultancy; BioLineRx: Consultancy; BiVictriX: Consultancy; Boehringer Ingelheim: Consultancy; Boston Biomedical: Consultancy; Covagen: Consultancy; Daiichi Sankyo: Consultancy; Jazz Pharmaceuticals: Consultancy; Kite Pharma: Consultancy; New Link Genetics: Consultancy; Pfizer: Consultancy, Research Funding; Race Oncology: Consultancy; Seattle Genetics: Research Funding.

Introduction: CD19-specific chimeric antigen receptor (CAR) T-cell therapy is FDA approved in patients with relapsed or refractory large B-cell lymphomas. While 35-40% of patients may achieve a durable complete response (CR), the toxicity incurred with CAR-T therapy could impact the ability to receive subsequent treatment in those who progress after CAR-T infusion. Our prior data suggested that patients who experienced early progression had inferior overall survival. We now update our results and evaluate the impact of laboratory abnormalities and comorbidities at the time of progression on overall survival. Methods: Adults with large B-cell lymphomas who received CD19-specific CAR T-cells at the University of Washington/Seattle Cancer Care Alliance were included. Patients who received CAR T-cell therapy with additional concurrent protocol-specified therapy were excluded. Those who exhibited progressive disease (PD) or persistent lymphoma after CAR T-cell therapy were the focus of this study. We defined patients who progressed or received additional lymphoma directed therapy after last CAR-T cell infusion as early PD, with all other patients defined as late PD. We collected laboratory data closest to the date of progression. We defined an absolute neutrophil count < 1000, platelet count < 75K, Creatinine > upper limit of normal (ULN), INR > ULN, AST/ALT > 2.5x ULN, total bilirubin > ULN, and LDH > ULN as abnormal. Primary endpoint of this analysis was overall survival (OS) landmarked to date of progression. Secondary endpoints include sub-group analyses based on early PD as well as lab abnormalities at the time of progression. A multi-variate analysis with select baseline and progression variables was also performed. Results: We identified 66 patients who met the above criteria. Median follow up for the entire cohort is 30.4 months (range 0.1-64 months) by reverse KM method. Median time from last planned CAR infusion to progression was 43.5 days (range 11-658). Median OS of the entire cohort was 5.43 months (95% CI 3.75-12.2). 25 (38%) patients experienced early PD, which was associated with inferior OS (median 3.75 vs. 10.4 months, P=0.02). LDH > ULN at the time of progression defined a group with inferior outcomes (median OS 3.16 vs. 17.5 months, P1 indicator of hematologic and/or organ dysfunction (excluding LDH) at the time of progression had worse outcomes compared to those with one or fewer abnormalities (median OS 1.74 vs. 7.14 months, P=0.001). Multivariate analysis identified pre-CAR IPI score 4-5 (HR 6.33, 95% CI 1.97-20.36), LDH > ULN at progression (7.01, 95% CI 2.89-17.013), and abnormal creatinine at progression (5.32, 95% CI 1.71-16.53), as factors associated with increased risk of death. Conclusions: Patients with PD post CD19-specific CAR T-cell therapy, particularly those with early PD, elevated LDH, or renal failure experience extremely poor outcomes. These data can inform discussion of prognosis for patients who progress after CAR T-cell therapy and may predict which patients may benefit from additional anti-lymphoma therapy. Figure Disclosures Lynch: Johnson Graffe Keay Moniz & Wick LLP: Consultancy; Juno Therapeutics: Research Funding; Takeda Pharmaceuticals: Research Funding; T.G. Therapeutics: Research Funding; Incyte Corporation: Research Funding; Rhizen Pharmaceuticals S.A: Research Funding. Maloney:A2 Biotherapeutics: Honoraria, Other: Stock options ; Celgene,Kite Pharma: Honoraria, Research Funding; Juno Therapeutics: Honoraria, Patents & Royalties: patients pending , Research Funding; BioLine RX, Gilead,Genentech,Novartis: Honoraria. Turtle:Nektar Therapeutics: Other: Ad hoc advisory board member, Research Funding; Juno Therapeutics: Patents & Royalties: Co-inventor with staff from Juno Therapeutics; pending, Research Funding; Eureka Therapeutics: Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Caribou Biosciences: Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Novartis: Other: Ad hoc advisory board member; Precision Biosciences: Equity Ownership, Membership on an entity's Board of Directors or advisory committees; T-CURX: Membership on an entity's Board of Directors or advisory committees; Allogene: Other: Ad hoc advisory board member; Kite/Gilead: Other: Ad hoc advisory board member; Humanigen: Other: Ad hoc advisory board member. Smith:Portola Pharmaceuticals: Research Funding; Pharmacyclics: Research Funding; Ignyta (spouse): Research Funding; Genentech: Research Funding; Denovo Biopharma: Research Funding; Ayala (spouse): Research Funding; Bristol-Myers Squibb (spouse): Research Funding; AstraZeneca: Membership on an entity's Board of Directors or advisory committees, Research Funding; Acerta Pharma BV: Research Funding; Merck Sharp & Dohme Corp: Consultancy, Research Funding; Seattle Genetics: Research Funding; Incyte Corporation: Research Funding. Shadman:TG Therapeutic: Research Funding; Mustang Bio: Research Funding; Atara Biotherapeutics: Consultancy; Pharmacyclics: Consultancy, Research Funding; Genentech: Consultancy, Research Funding; AbbVie: Consultancy, Research Funding; Sunesis: Research Funding; Verastem: Consultancy; Astra Zeneca: Consultancy; ADC Therapeutics: Consultancy; Sound Biologics: Consultancy; Celgene: Research Funding; Gilead: Consultancy, Research Funding; BeiGene: Research Funding; Acerta Pharma: Research Funding. Ujjani:Pharmacyclics: Honoraria; Atara: Consultancy; Gilead: Consultancy; Genentech: Honoraria; Astrazeneca: Consultancy; AbbVie: Honoraria, Research Funding; PCYC: Research Funding. Cassaday:Amgen: Consultancy, Research Funding; Pfizer: Consultancy, Honoraria, Research Funding; Incyte: Research Funding; Kite/Gilead: Research Funding; Merck: Research Funding; Seattle Genetics: Research Funding; Seattle Genetics: Other: Spouse's disclosure: employment, stock and other ownership interests. Till:Mustang Bio: Patents & Royalties, Research Funding. Shustov:Seattle Genetics, Inc.: Research Funding. Gopal:Seattle Genetics, Pfizer, Janssen, Gilead, Sanofi, Spectrum, Amgen, Aptevo, BRIM bio, Acerta, I-Mab-pharma, Takeda, Compliment, Asana Bio, and Incyte.: Consultancy; Seattle Genetics, Pfizer, Janssen, Gilead, Sanofi, Spectrum, Amgen, Aptevo, BRIM bio, Acerta, I-Mab-pharma, Takeda, Compliment, Asana Bio, and Incyte: Honoraria; Teva, Bristol-Myers Squibb, Merck, Takeda, Seattle Genetics, Pfizer, Janssen, Takeda, and Effector: Research Funding.

Background: Patients infected with HIV have an 8 to 150-fold risk of lymphoma compared to HIV uninfected patients, with certain aggressive non-Hodgkin lymphoma (NHL) histologies being AIDS-defining. Despite the decrease in incidence of both NHL and Hodgkin lymphoma (HL) in the current anti-retroviral treatment (ART) era, HIV-infected patients remain at significantly increased risk of lymphoma compared to the general population. Over the last decade, advances have been made in the treatment of both NHL and HL with 18 agents approved since 2009. Unfortunately, safety and efficacy data in the HIV-infected population have been lacking in part due to exclusion of such patients from clinical trials. As such, the optimal treatment of HIV-associated lymphomas is unknown. In 2017, the National Comprehensive Care Network (NCCN) and the American Society of Clinical Oncology (ASCO) advocated expanding clinical trial opportunities for HIV-infected patients. However, exclusion criteria precluding HIV-infected patient participation likely persist. We sought to document and describe the current status of clinical trial exclusion criteria for NHL and HL as they relate to HIV infection. Methods We extracted data from the National Institute of Health's (NIH) registry of clinical trials (ClinicalTrials.gov) using the search term 'lymphoma' and reviewed all clinical trials (independent of funding source) in the United States that were recruiting or not yet recruiting adult patients for therapeutic trials (phase 1, 2, or 3) as of June 2019. A total of 734 trials met the above criteria; of these 206 were excluded as they were not primarily adult lymphoma trials (allogeneic transplant [n=87], leukemia [n=79], pediatric [n=87], lung cancer [n=12], and other [n=12]). As such, 526 clinical trials were included in the final sample. The primary outcome measure was whether HIV infection was an exclusion criterion for participation in the clinical trial. With the exception of the sample size, which was measured as a continuous variable, explanatory variables were dichotomized and included funding source (NIH vs. non-NIH), phase (phase 1 vs. phase 2 or 3), start date (start date prior to January 2018 vs. start date on or after January 2018), and recruitment status (recruiting vs. not yet recruiting). If the lymphoma under study was an aggressive subtype it was dichotomized as an AIDS-defining malignancy (aggressive NHL vs. other). We assessed whether these explanatory variables were associated with the primary outcome measure. We utilized bivariate analyses to identify measures with p < 0.20 for inclusion in a multivariate logistic regression model. Results: Of the 526 lymphoma-related trials, 352 (66.9%) excluded HIV-infected patients. Among all studies, the target sample sizes of these studies ranged from 6 to 6,542 (median 52) and were primarily phase 1 (219; 41.6%) or phase 2 (277; 52.7%) studies. Only 30 of the clinical trials were phase 3 (5.7%). The majority of studies (493; 93.7%) were actively recruiting and were initiated prior to January 1, 2018 (302; 57.4%). The majority of the 526 trials (320; 60.8%) included patients with aggressive NHL. The remaining trials included patients with indolent lymphoma, HL, or NHL with an unspecified subtype. Only 39 (7.4%) of all studies were funded strictly by NIH; the remainder were funded strictly by industry (192; 36.5%), 'other' (107; 20.3%), or a combination (188; 35.7%).[Table 1] Of the explanatory variables, funding source, sample size, and a start date on or after January 1, 2018 were associated with the outcome measure in the bivariate analysis and were included in a multivariate model. In the multivariate analyses, NIH-funded studies (OR 0.34 [0.17, 0.67], studies which began recruitment after January 1, 2018 (OR 0.66 [0.45, 0.97]) and larger studies (OR 0.998 [0.996, 0.999] were less likely to exclude HIV-infected patients. [Table 2] Conclusions: Despite support from ASCO and specific NCCN guidance which advocates that the participation in cancer clinical trials of patients living with HIV/AIDS "should be encouraged whenever feasible," the majority of interventional clinical trials for the treatment of lymphoma currently exclude participants based on infection with HIV. This goal of inclusion could be accomplished by adding an additional HIV-specific safety and efficacy cohort to most studies which could potentially be mandated by the FDA for all registrational trials. Disclosures Lynch: Rhizen Pharmaceuticals S.A: Research Funding; Takeda Pharmaceuticals: Research Funding; T.G. Therapeutics: Research Funding; Incyte Corporation: Research Funding; Johnson Graffe Keay Moniz & Wick LLP: Consultancy; Juno Therapeutics: Research Funding. Shadman:Sound Biologics: Consultancy; Acerta: Research Funding; Pharmacyclics: Consultancy, Research Funding; Celgene: Research Funding; Gilead: Research Funding; TG Therapeutics: Research Funding; Atara: Consultancy; Verastem: Consultancy; Mustang Biopharma: Research Funding; Bigene: Research Funding; ADC Therapeutics: Consultancy; Merck: Research Funding; AbbVIe: Consultancy, Research Funding; Sunesis: Research Funding; Genentech, Inc.: Consultancy, Research Funding; Emergent: Research Funding; AstraZeneca: Consultancy. Shustov:Spectrum Pharmaceuticals: Consultancy, Research Funding. Smith:AstraZeneca: Membership on an entity's Board of Directors or advisory committees, Research Funding; Acerta Pharma BV: Research Funding; Merck Sharp & Dohme Corp: Consultancy, Research Funding; Denovo Biopharma: Research Funding; Genentech: Research Funding; Ignyta (spouse): Research Funding; Bristol-Myers Squibb (spouse): Research Funding; Ayala (spouse): Research Funding; Pharmacyclics: Research Funding; Portola Pharmaceuticals: Research Funding; Seattle Genetics: Research Funding; Incyte Corporation: Research Funding. Till:Mustang Bio: Patents & Royalties, Research Funding. Ujjani:PCYC: Research Funding; Pharmacyclics: Honoraria; Pharmacyclics: Honoraria; Genentech: Honoraria; PCYC: Research Funding; Gilead: Consultancy; Gilead: Consultancy; Astrazeneca: Consultancy; Astrazeneca: Consultancy; Atara: Consultancy; Genentech: Honoraria; Atara: Consultancy; AbbVie: Honoraria, Research Funding; AbbVie: Honoraria, Research Funding. Uldrick:Roche: Other: commercial research support through a CTA with Fred Hutchinson Cancer Research Center; Merck: Other: drug for a clinical trial from Merck through a CRADA with the NCI; Celgene: Other: research support from Celgene through a CRADA at the NCI; Patent: Patents & Royalties: co-inventor on US Patent 10,001,483 entitled . Gopal:Seattle Genetics, Pfizer, Janssen, Gilead, Sanofi, Spectrum, Amgen, Aptevo, BRIM bio, Acerta, I-Mab-pharma, Takeda, Compliment, Asana Bio, and Incyte.: Consultancy; Seattle Genetics, Pfizer, Janssen, Gilead, Sanofi, Spectrum, Amgen, Aptevo, BRIM bio, Acerta, I-Mab-pharma, Takeda, Compliment, Asana Bio, and Incyte: Honoraria; Teva, Bristol-Myers Squibb, Merck, Takeda, Seattle Genetics, Pfizer, Janssen, Takeda, and Effector: Research Funding.

Introduction: Peripheral T-cell lymphomas (PTCL) represent a heterogeneous group of aggressive non-Hodgkin lymphomas, with suboptimal outcomes with conventional chemotherapy. Autologous hematopoietic stem cell transplant (AHCT) is a therapeutic strategy for patients in first remission. However, progression-free survival (PFS) after AHCT is only 36-45% (d'Amore et al JCO 2012, Reimer et al JCO 2009), signifying an unmet therapeutic need for improving outcomes post-transplant. Maintenance therapy after AHCT may improve PFS. Romidepsin is a histone deacetylase (HDAC) inhibitor that is FDA approved for the treatment of relapsed/refractory T-cell lymphoma, and is a potential option for maintenance therapy. We present the results of the first multicenter study to evaluate the PFS of patients receiving maintenance therapy after upfront AHCT in PTCL patients. Methods: This was a phase 2, open-label, multicenter, investigator-initiated study in adult patients with PTCL (Table 1). 25 patients transplanted in first complete response or first partial response (CR1 or PR1) (Cohort 1) were evaluable for the primary endpoint of 2-year PFS. We enrolled another cohort (n=8) with high-risk histologies in CR/PR1 (n= 1), or transplanted in CR/PR2 or later (n=7) (Cohort 2). Patients underwent AHCT with carmustine, etoposide, cytarabine and melphalan (BEAM) conditioning. Maintenance romidepsin 14 mg/m2 was initiated between days 42-80 post AHCT, and administered every other week through 6 months, every 3 weeks through 1 year and every 4 weeks from 1 year through 2 years post AHCT. The Kaplan-Meier method was used to estimate PFS. Desired 2-year PFS was 70%. Results: Table 1 lists patient and disease characteristics. In Cohort 1, median follow up was 13.8 months (3.5 - 54.1 mon). Estimated 2-year PFS was 49% (30 - 80, 95% CI) (Figure 1). Median PFS was 20.0 months (12.0- NA, 95% CI). In Cohort 2, median follow up was 23.2 months (range, 9.1 - 35.7 months). Median PFS was 13.9 months (5.6 - NA, 95% CI). Estimated 2-year PFS was 47% (21 - 100, 95% CI). Angioimmunoblastic T-cell lymphoma (AITL) patients represented the largest subgroup within the study. 2-year PFS of these patients in Cohort 1 was 44% (20-96, 95% CI). In Cohort 1, 16 patients are off therapy (9 for disease progression, 2 for toxicity, 2 for patient choice and 3 completed therapy). Across cohorts, 5 patients required dose reduction. 6 patients experienced ≥ grade 3 toxicity (neutropenia=4, anemia=2, thrombocytopenia=2 and lymphopenia=2). 8 serious adverse events (SAEs) occurred in 6 patients after romidepsin treatment (epistaxis, fever, febrile neutropenia, hypotension, fatigue, myalgia, generalized muscle weakness, dyspnea, and CMV retinitis). Grade 2 toxicities included dysgeusia (5), neutropenia (3), anorexia (2), atrial fibrillation (1), hematuria (1), nausea (1), and fatigue (1). Grade 1 toxicities included dysgeusia (7), fatigue (4), nausea (4), anorexia (2), constipation (2), diarrhea (1), neutropenia (1), thrombocytopenia (1), and vomiting (1). Conclusions: Maintenance romidepsin was overall well-tolerated without significant additional grade 3-4 toxicity. At first assessment, the estimated median 2-year PFS in Cohort 1 of 49% does not indicate PFS improvement with romidepsin maintenance. Enrollment is complete and 9 patients in Cohort 1 are still on treatment. Final PFS will be updated. Disclosures Khan: ASCO/Conquer Cancer Foundation sponsored by Gilead Sciences: Research Funding; Back Bay Life Science Advisors: Honoraria. Shustov:Seattle Genetics, Inc.: Research Funding. Shadman:Sound Biologics: Consultancy; Sunesis: Research Funding; ADC Therapeutics: Consultancy; BeiGene: Research Funding; Pharmacyclics: Consultancy, Research Funding; Verastem: Consultancy; Celgene: Research Funding; TG Therapeutic: Research Funding; Gilead: Consultancy, Research Funding; AbbVie: Consultancy, Research Funding; Genentech: Consultancy, Research Funding; Acerta Pharma: Research Funding; Astra Zeneca: Consultancy; Atara Biotherapeutics: Consultancy; Mustang Bio: Research Funding. Cassaday:Kite/Gilead: Research Funding; Amgen: Consultancy, Research Funding; Pfizer: Consultancy, Honoraria, Research Funding; Merck: Research Funding; Seattle Genetics: Research Funding; Seattle Genetics: Other: Spouse's disclosure: employment, stock and other ownership interests; Incyte: Research Funding. Ruan:AstraZeneca: Consultancy, Honoraria; Seattle Genetics: Consultancy, Honoraria, Research Funding; Celgene: Consultancy, Honoraria, Research Funding; Janssen: Consultancy, Honoraria; Pharmacyclics LLC, an AbbVie company: Research Funding; Juno: Consultancy; Kite: Consultancy. Moskowitz:Takeda Pharmaceuticals: Consultancy; Merck: Research Funding; ADC Therapeutics: Consultancy; Erytech Pharma: Consultancy; Incyte: Research Funding; Bristol-Myers Squibb: Consultancy, Research Funding; Erytech Pharma: Consultancy; Incyte: Research Funding; ADC Therapeutics: Consultancy; Merck: Research Funding; miRagen Therapeutics Inc: Consultancy, Research Funding; Bristol-Myers Squibb: Consultancy, Research Funding; miRagen Therapeutics Inc: Consultancy, Research Funding; Seattle Genetics: Consultancy, Honoraria, Research Funding; Kyowa Hakko Kirin Pharma: Consultancy, Research Funding; Incyte: Research Funding; Takeda Pharmaceuticals: Consultancy; ADC Therapeutics: Consultancy; miRagen Therapeutics Inc: Consultancy, Research Funding; ADC Therapeutics: Consultancy; Incyte: Research Funding; ADC Therapeutics: Consultancy; Bristol-Myers Squibb: Consultancy, Research Funding; ADC Therapeutics: Consultancy; ADC Therapeutics: Consultancy; Bristol-Myers Squibb: Consultancy, Research Funding; Bristol-Myers Squibb: Consultancy, Research Funding; Seattle Genetics: Consultancy, Honoraria, Research Funding; Seattle Genetics: Consultancy, Honoraria, Research Funding; Cell Medica: Consultancy; Kyowa Hakko Kirin Pharma: Consultancy, Research Funding; Bristol-Myers Squibb: Consultancy, Research Funding; Erytech Pharma: Consultancy; Erytech Pharma: Consultancy; Bristol-Myers Squibb: Consultancy, Research Funding; Incyte: Research Funding; Merck: Research Funding; Merck: Research Funding; Kyowa Hakko Kirin Pharma: Consultancy, Research Funding; Kyowa Hakko Kirin Pharma: Consultancy, Research Funding; Merck: 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; Seattle Genetics: Consultancy, Honoraria, Research Funding; Seattle Genetics: Consultancy, Honoraria, Research Funding; Seattle Genetics: Consultancy, Honoraria, Research Funding; Merck: Research Funding; miRagen Therapeutics Inc: Consultancy, Research Funding; Cell Medica: Consultancy; Merck: Research Funding; miRagen Therapeutics Inc: Consultancy, Research Funding; Takeda Pharmaceuticals: Consultancy; ADC Therapeutics: Consultancy; Bristol-Myers Squibb: Consultancy, Research Funding; ADC Therapeutics: Consultancy; Erytech Pharma: Consultancy; Erytech Pharma: Consultancy; Incyte: Research Funding; ADC Therapeutics: Consultancy; ADC Therapeutics: Consultancy; Kyowa Hakko Kirin Pharma: Consultancy, Research Funding; Takeda Pharmaceuticals: Consultancy; Takeda Pharmaceuticals: Consultancy; Seattle Genetics: Consultancy, Honoraria, Research Funding; Takeda Pharmaceuticals: Consultancy; Takeda Pharmaceuticals: Consultancy; Seattle Genetics: Consultancy, Honoraria, Research Funding; Kyowa Hakko Kirin Pharma: Consultancy, Research Funding; Merck: Research Funding; Kyowa Hakko Kirin Pharma: Consultancy, Research Funding; Seattle Genetics: Consultancy, Honoraria, Research Funding; Merck: Research Funding; Kyowa Hakko Kirin Pharma: Consultancy, Research Funding; Takeda Pharmaceuticals: Consultancy; Takeda Pharmaceuticals: Consultancy; miRagen Therapeutics Inc: Consultancy, Research Funding; Cell Medica: Consultancy; Kyowa Hakko Kirin Pharma: Consultancy, Research Funding; Cell Medica: Consultancy; Kyowa Hakko Kirin Pharma: Consultancy, Research Funding; Seattle Genetics: Consultancy, Honoraria, Research Funding; Seattle Genetics: Consultancy, Honoraria, Research Funding; Takeda Pharmaceuticals: Consultancy; ADC Therapeutics: Consultancy; Takeda Pharmaceuticals: Consultancy; Incyte: Research Funding; Seattle Genetics: Consultancy, Honoraria, Research Funding; miRagen Therapeutics Inc: Consultancy, Research Funding; Kyowa Hakko Kirin Pharma: Consultancy, Research Funding; Merck: Research Funding; Seattle Genetics: Consultancy, Honoraria, Research Funding; miRagen Therapeutics Inc: Consultancy, Research Funding; Merck: Research Funding; Cell Medica: Consultancy; Merck: Research Funding; Merck: Research Funding; miRagen Therapeutics Inc: Consultancy, Research Funding; Bristol-Myers Squibb: Consultancy, Research Funding; Bristol-Myers Squibb: Consultancy, Research Funding; Bristol-Myers Squibb: Consultancy, Research Funding; Erytech Pharma: Consultancy; Merck: Research Funding; Kyowa Hakko Kirin Pharma: Consultancy, Research Funding; Merck: Research Funding; ADC Therapeutics: Consultancy; Erytech Pharma: Consultancy; Erytech Pharma: Consultancy; Erytech Pharma: Consultancy; Bristol-Myers Squibb: Consultancy, Research Funding; Bristol-Myers Squibb: Consultancy, Research Funding; miRagen Therapeutics Inc: Consultancy, Research Funding; Incyte: Research Funding; Takeda Pharmaceuticals: Consultancy; Erytech Pharma: Consultancy; Seattle Genetics: Consultancy, Honoraria, Research Funding; Incyte: Research Funding; Incyte: Research Funding; Incyte: Research Funding; miRagen Therapeutics Inc: Consultancy, Research Funding; miRagen Therapeutics Inc: Consultancy, Research Funding; Cell Medica: Consultancy; Cell Medica: Consultancy; Cell Medica: Consultancy; Cell Medica: Consultancy; Cell Medica: Consultancy; Cell Medica: Consultancy; Incyte: Research Funding; Takeda Pharmaceuticals: Consultancy; Takeda Pharmaceuticals: Consultancy; Incyte: Research Funding; Takeda Pharmaceuticals: Consultancy; ADC Therapeutics: Consultancy; ADC Therapeutics: Consultancy; Erytech Pharma: Consultancy; Cell Medica: Consultancy; Cell Medica: Consultancy; Kyowa Hakko Kirin Pharma: Consultancy, Research Funding; Seattle Genetics: Consultancy, Honoraria, Research Funding; Bristol-Myers Squibb: Consultancy, Research Funding; Erytech Pharma: Consultancy; Cell Medica: Consultancy; Kyowa Hakko Kirin Pharma: Consultancy, Research Funding; Cell Medica: Consultancy; Erytech Pharma: Consultancy; Erytech Pharma: Consultancy; miRagen Therapeutics Inc: Consultancy, Research Funding. Zelenetz:Pfizer: Consultancy, Membership on an entity's Board of Directors or advisory committees; DAVA Oncology: Consultancy, Membership on an entity's Board of Directors or advisory committees; Amgen: Consultancy, Membership on an entity's Board of Directors or advisory committees; Genentech/Roche: Consultancy, Membership on an entity's Board of Directors or advisory committees; Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees; Bayer: Consultancy, Membership on an entity's Board of Directors or advisory committees; Morphosys: Consultancy, Membership on an entity's Board of Directors or advisory committees; Beigene: Consultancy, Membership on an entity's Board of Directors or advisory committees; Beigene: Consultancy, Membership on an entity's Board of Directors or advisory committees; Pharmacyclics/AbbVie: Consultancy, Membership on an entity's Board of Directors or advisory committees; Karyopharm: Consultancy, Membership on an entity's Board of Directors or advisory committees; MEI Pharma: Consultancy, Membership on an entity's Board of Directors or advisory committees; Amgen: Consultancy, Membership on an entity's Board of Directors or advisory committees; Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees; Astra-Zeneca: Consultancy, Membership on an entity's Board of Directors or advisory committees; Gilead: Consultancy, Membership on an entity's Board of Directors or advisory committees; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees; Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees; Morphosys: Consultancy, Membership on an entity's Board of Directors or advisory committees; Verastem: Consultancy, Membership on an entity's Board of Directors or advisory committees; Karyopharm: Consultancy, Membership on an entity's Board of Directors or advisory committees; Astra-Zeneca: Consultancy, Membership on an entity's Board of Directors or advisory committees; Bayer: Consultancy, Membership on an entity's Board of Directors or advisory committees; MEI Pharma: Consultancy, Membership on an entity's Board of Directors or advisory committees; Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees; DAVA Oncology: Consultancy, Membership on an entity's Board of Directors or advisory committees; Pharmacyclics/AbbVie: Consultancy, Membership on an entity's Board of Directors or advisory committees; Genentech/Roche: Consultancy, Membership on an entity's Board of Directors or advisory committees; Pfizer: Consultancy, Membership on an entity's Board of Directors or advisory committees; Verastem: Consultancy, Membership on an entity's Board of Directors or advisory committees; Gilead: Consultancy, Membership on an entity's Board of Directors or advisory committees. Noy:Medscape: Honoraria; Janssen: Consultancy; Prime Oncology: Honoraria; NIH: Research Funding; Pharamcyclics: Research Funding; Raphael Pharma: Research Funding. Straus:Hope Funds for Cancer Research: Membership on an entity's Board of Directors or advisory committees; Elsevier (PracticeUpdate): Consultancy, Honoraria; Seattle Genetics: Consultancy, Honoraria. Kumar:Seattle Genetics: Research Funding. Sauter:Celgene: Consultancy; Novartis: Consultancy; Genmab: Consultancy; Precision Biosciences: Consultancy; Kite/Gilead: Consultancy; Juno Therapeutics: Consultancy, Research Funding; Sanofi-Genzyme: Consultancy, Research Funding; Spectrum Pharmaceuticals: Consultancy; GSK: Consultancy. Shah:Amgen: Research Funding; Janssen: Research Funding. Matasar:Genentech, Inc.: Consultancy, Honoraria, Other: Travel, accommodation, expenses , Research Funding; Bayer: Consultancy, Honoraria, Other; Roche: Consultancy, Honoraria, Other: Travel, accommodation, expenses , Research Funding; Merck: Consultancy, Equity Ownership; Juno Therapeutics: Consultancy; Teva: Consultancy; Rocket Medical: Consultancy, Research Funding; Seattle Genetics: Consultancy, Honoraria, Other: Travel, accomodation, expenses, Research Funding; Daiichi Sankyo: Consultancy; GlaxoSmithKline: Honoraria, Research Funding; Pharmacyclics: Consultancy, Honoraria, Research Funding; Janssen: Honoraria, Research Funding; Bayer: Other: Travel, accommodation, expenses. Van Besien:Miltenyi Biotec: Research Funding. Giralt:Sanofi: Consultancy, Research Funding; Amgen: Consultancy, Research Funding; Celgene: Consultancy, Research Funding; Takeda: Consultancy. Horwitz:Mundipharma: Consultancy; Astex: Consultancy; Trillium: Research Funding; Kyowa Hakko Kirin: Consultancy; Millennium/Takeda: Consultancy, Research Funding; Corvus Pharmaceuticals: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Portola: Consultancy; Aileron: Research Funding; Miragen: Consultancy; Celgene: Consultancy, Research Funding; Kura: Consultancy; Millennium/Takeda: Consultancy, Research Funding; Portola: Consultancy; ADCT Therapeutics: Research Funding; Innate Pharma: Consultancy; Affimed: Consultancy; Aileron: Research Funding; Seattle Genetics: Consultancy, Research Funding; Seattle Genetics: Consultancy, Research Funding; Corvus Pharmaceuticals: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Infinity/Verastem: Consultancy, Research Funding; ADCT Therapeutics: Research Funding; Corvus Pharmaceuticals: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Astex: Consultancy; Innate Pharma: Consultancy; Kyowa Hakko Kirin: Consultancy; Seattle Genetics: Consultancy, Research Funding; Mundipharma: Consultancy; Affimed: Consultancy; Forty-Seven: Research Funding; Portola: Consultancy; Trillium: Research Funding; Affimed: Consultancy; Miragen: Consultancy; Astex: Consultancy; Millennium/Takeda: Consultancy, Research Funding; Miragen: Consultancy; Astex: Consultancy; Infinity/Verastem: Consultancy, Research Funding; Mundipharma: Consultancy; Celgene: Consultancy, Research Funding; Celgene: Consultancy, Research Funding; Kura: Consultancy; Corvus Pharmaceuticals: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Forty-Seven: Research Funding; Portola: Consultancy; Mundipharma: Consultancy; Aileron: Research Funding; Kura: Consultancy; Celgene: Consultancy, Research Funding; Infinity/Verastem: Consultancy, Research Funding; Infinity/Verastem: Consultancy, Research Funding; Seattle Genetics: Consultancy, Research Funding; Kura: Consultancy; Innate Pharma: Consultancy; Aileron: Research Funding; Kyowa Hakko Kirin: Consultancy; Millennium/Takeda: Consultancy, Research Funding; Miragen: Consultancy; Affimed: Consultancy; ADCT Therapeutics: Research Funding; Trillium: Research Funding; Kyowa Hakko Kirin: Consultancy; Forty-Seven: Research Funding; Forty-Seven: Research Funding; Trillium: Research Funding; Innate Pharma: Consultancy; ADCT Therapeutics: Research Funding. OffLabel Disclosure: Romidepsin has been FDA approved for the treatment of relapsed/refractory cutaneous T-cell lymphoma and has accelerated approval for treatment of relapsed/refractory peripheral T cell lymphoma. We are studying its use as maintenance therapy after autologous stem cell transplant.

Background: Angioimmunoblastic T-cell lymphoma (AITL) is a relatively common subtype of peripheral T-cell lymphoma (PTCL) that typically presents with lymphadenopathy, extranodal disease, including rash, and is associated with frequent infections due to immune dysregulation. Patients with AITL generally have a poor prognosis, even with aggressive chemotherapy as responses to standard chemotherapy are often suboptimal. Recent advances in cancer biology suggest that AITL is derived from T-follicular helper cells and is often characterized by gross epigenetic dysregulation. Histone deacetylase (HDAC) inhibitors have demonstrated significant activity in T-cell neoplasms. The BELIEF trial established an overall response rate of 25% in patients with relapsed/refractory PTCL who were treated with belinostat, with a duration of response of about 1 year, leading to accelerated approval. Herein, we present a subset analysis of the data for patients with AITL. Methods: Patients with histologically confirmed PTCL (N = 129) who experienced failure with or refractory to ≥ 1 prior systemic therapy received belinostat 1,000 mg/m(2) as daily 30-minute infusions on days 1 to 5 every 21 days. Central assessment of response used International Working Group criteria. Primary endpoint was overall response rate (ORR). Secondary endpoints included duration of response (DoR) and progression-free and overall survival (PFS). Results: Of 129 patients, 22 patients had AITL; most had advanced disease (91% stage III/IV; 36% with bone marrow involvement). The median number of prior therapies was 2 (range, 1-5), and 3 (14%) patients were refractory to their last line of therapy. The ORR for patients with AITL was 46% (10/22; 95%CI: 24 - 68%), with a complete response (CR) in 4 of 22 patients (18%). Of the ten responders, the median time to response of 11.3 weeks (range, 4.7 - 24.4 weeks) in the AITL subgroup. After a median follow up of 21.5 months, the median PFS was 4.2 months (95%CI: 1.5 -13.9) and the median DOR was 13.6 months (95%CI: 1.4 - 29.4) as shown in Figure 1. For all patients with AITL treated with belinostat, the median OS was 9.2 months (95%CI: 6.8 - 21.5). The most common grade 3 to 4 adverse events were asthenia (n=2), fatigue (n=2), anemia (n=2), thrombocytopenia (n=2), neutropenia (n=2), and septic shock (n=2). Conclusions: Single-agent belinostat induced rapid and durable responses in patients with relapsed/refractory AITL. At the end of the study, there were 37% patients with ongoing responses at 2 years. Patients with clinical benefit from belinostat continued treatment until progression of disease. These results support the use of belinostat in relapsed/refractory AITL as a single agent and provide rationale for combination therapies in clinical trials. Disclosures Sawas: Seattle Genetics, Gilead, Daiichi Sanko: Consultancy; Affimed: Research Funding. Shustov:Spectrum Pharmaceuticals: Consultancy, Research Funding. Hsu:Spectrum Pharmaceuticals: Employment. Bhat:Spectrum Pharmaceuticals: Employment. Acosta:Acrotech Biopharma: Employment. Horwitz:Astex: Consultancy; Kyowa Hakko Kirin: Consultancy; Infinity/Verastem: Consultancy, Research Funding; Innate Pharma: Consultancy; Kyowa Hakko Kirin: Consultancy; Trillium: Research Funding; Affimed: Consultancy; ADCT Therapeutics: Research Funding; Kura: Consultancy; ADCT Therapeutics: Research Funding; Aileron: Research Funding; Seattle Genetics: Consultancy, Research Funding; Corvus Pharmaceuticals: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Trillium: Research Funding; Aileron: Research Funding; Trillium: Research Funding; Miragen: Consultancy; Millennium/Takeda: Consultancy, Research Funding; Infinity/Verastem: Consultancy, Research Funding; Kura: Consultancy; Forty-Seven: Research Funding; Millennium/Takeda: Consultancy, Research Funding; ADCT Therapeutics: Research Funding; Mundipharma: Consultancy; Kura: Consultancy; Miragen: Consultancy; Corvus Pharmaceuticals: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Mundipharma: Consultancy; Astex: Consultancy; Seattle Genetics: Consultancy, Research Funding; Astex: Consultancy; Portola: Consultancy; Celgene: Consultancy, Research Funding; Celgene: Consultancy, Research Funding; Infinity/Verastem: Consultancy, Research Funding; Aileron: Research Funding; Trillium: Research Funding; Forty-Seven: Research Funding; Infinity/Verastem: Consultancy, Research Funding; Innate Pharma: Consultancy; Miragen: Consultancy; Millennium/Takeda: Consultancy, Research Funding; Mundipharma: Consultancy; Portola: Consultancy; Mundipharma: Consultancy; Portola: Consultancy; Aileron: Research Funding; Forty-Seven: Research Funding; Kura: Consultancy; Kyowa Hakko Kirin: Consultancy; Seattle Genetics: Consultancy, Research Funding; Portola: Consultancy; ADCT Therapeutics: Research Funding; Corvus Pharmaceuticals: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Astex: Consultancy; Innate Pharma: Consultancy; Kyowa Hakko Kirin: Consultancy; Miragen: Consultancy; Affimed: Consultancy; Affimed: Consultancy; Corvus Pharmaceuticals: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Consultancy, Research Funding; Celgene: Consultancy, Research Funding; Innate Pharma: Consultancy; Seattle Genetics: Consultancy, Research Funding; Forty-Seven: Research Funding; Affimed: Consultancy; Millennium/Takeda: Consultancy, Research Funding. O'Connor:Mundipharma: Consultancy, Membership on an entity's Board of Directors or advisory committees; ADCT Therapeutics, Affimed, Agensys, Merck, Seattle Genetics, Spectrum, Trillium, and Verastem Oncology.: Research Funding; TG Therapeutics: Other: Travel Support, Research Funding; Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding.

INTRODUCTION While chemoimmunotherapy is effective in indolent B-cell non-Hodgkin lymphoma (iBCL), most patients are older and may benefit from a chemotherapy-free approach. Pembrolizumab is an immune checkpoint inhibitor which blocks the PD-1 receptor. Upon chronic antigen stimulation, T-cells can lose their anti-tumor activity due to PD-1 signaling. Multiple in vitro and in vivo studies have demonstrated that blockade of PD-1 can reverse the T-cell dysfunction induced by the tumor microenvironment. Pembrolizumab has shown an excellent safety and toxicity profile. Pembrolizumab as a single agent is FDA approved for numerous solid tumors and some lymphoma subtypes including Hodgkin lymphoma and primary mediastinal B-cell lymphoma. PD-1 inhibitors have also shown activity in the relapsed/refractory iBCL with overall responses reported to range from 10 to 60% (Ding et al., 2017; Lesokhin et al., 2016; Nastoupil et al., 2017a). However, the overwhelming majority of the patients in these studies had received prior chemotherapy. Patients with untreated iBCL have a relatively intact immune system and may have a greater capacity to mount an effective anti-tumor immune response upon reversal of T-cell dysfunction. OBJECTIVES The primary objective is evaluate the efficacy of pembrolizumab as monotherapy for patients with untreated iBCL based on ORR measured at the end of a 6-cycle treatment period. Secondary objective include: Safety and toxicity.Efficacy including complete response, clinical benefit rate (complete response + partial response + stable disease) ≥6 months, time to next therapy, progression-free survival, and duration of response. SUBJECTS AND METHODS Patients ≥ 18 years of age with previously untreated radiographically measurable follicular or marginal zone lymphoma with an indication for treatment are included. These indications include significant symptoms, end organ damage, cytopenias, or steady progression. Major exclusions include known autoimmune disease, major organ dysfunction, or ECOG ≥ 2. Treatment consists of 200 mg pembrolizumab IV on day 1 of each 21-day cycle. Initial response assessment occurs after 6 cycles. Patients with a complete or partial response can remain on the trial. Patients who have stable disease or progressive disease and are asymptomatic (excluding hyperprogression) will receive 3 additional cycles and then will be restaged to account for a delayed response. Those patients with a complete or partial response after those additional cycles can remain on the trial. Subsequently, response assessment occurs every 3 cycles. Patients without progressive disease or unacceptable toxicity are able to continue up to 18 cycles. Up to 33 patients will be enrolled, and follow-up may continue for an additional 2 years. STATISTICAL METHODS The primary efficacy endpoint is the overall response rate (CR + PR). Secondary endpoints include duration of response, progression free survival, and time to next therapy (see treatment schema). A sample size of 33 participants is planned to provide 80% power at the 5% significance level to distinguish the observed overall response rate from a true rate of ≥ 40% versus ≤ 20%) using a Simon 2-stage minimax design. The trial will be terminated early if fewer than 5 of the first 18 patients have a response. The thresholds used in this design are based on what is considered to be a clinically meaningful response rate with a novel agent with very low rates of adverse events and toxicity compared to standard regimens. This response rate threshold is also higher than what has been observed using anti-PD-1 therapy in the relapsed/refractory setting. RECRUITMENT Three patients have been accrued to the study. To date, all patients have remained on study with no grade 3-5 adverse events. CORRELATIVE STUDIES Given that pembrolizumab is known to modulate the tumor immune microenvironment, we are also performing clinical correlates on a companion protocol. Using several 22 color flow cytometry panels and 6-color multiplex immunohistochemistry, we will analyze pre- and post-treatment lymph nodes and peripheral blood. These studies will examine over 50 populations of immune cells in addition to T-cell activation/exhaustion markers such as PD-1, TIM-3, LAG-3, CTLA-4, and PD-L1. TRIAL REGISTRATION Clinicaltrials.gov (NCT03498612). Funding for both the trial and correlative studies has been provided by Merck. Figure Disclosures Gopal: Seattle Genetics, Pfizer, Janssen, Gilead, Sanofi, Spectrum, Amgen, Aptevo, BRIM bio, Acerta, I-Mab-pharma, Takeda, Compliment, Asana Bio, and Incyte.: Consultancy; Seattle Genetics, Pfizer, Janssen, Gilead, Sanofi, Spectrum, Amgen, Aptevo, BRIM bio, Acerta, I-Mab-pharma, Takeda, Compliment, Asana Bio, and Incyte: Honoraria; Teva, Bristol-Myers Squibb, Merck, Takeda, Seattle Genetics, Pfizer, Janssen, Takeda, and Effector: Research Funding. Lynch:Rhizen Pharmaceuticals S.A: Research Funding; Johnson Graffe Keay Moniz & Wick LLP: Consultancy; T.G. Therapeutics: Research Funding; Takeda Pharmaceuticals: Research Funding; Incyte Corporation: Research Funding; Juno Therapeutics: Research Funding. Ujjani:Pharmacyclics: Honoraria; PCYC: Research Funding; Astrazeneca: Consultancy; Atara: Consultancy; Gilead: Consultancy; Genentech: Honoraria; AbbVie: Honoraria, Research Funding. Shadman:ADC Therapeutics: Consultancy; Genentech: Consultancy, Research Funding; Sound Biologics: Consultancy; Mustang Bio: Research Funding; TG Therapeutic: Research Funding; Pharmacyclics: Consultancy, Research Funding; Verastem: Consultancy; Gilead: Consultancy, Research Funding; Celgene: Research Funding; AbbVie: Consultancy, Research Funding; Acerta Pharma: Research Funding; BeiGene: Research Funding; Sunesis: Research Funding; Astra Zeneca: Consultancy; Atara Biotherapeutics: Consultancy. Smith:Denovo Biopharma: Research Funding; Incyte Corporation: Research Funding; Pharmacyclics: Research Funding; Genentech: Research Funding; Ignyta (spouse): Research Funding; Merck Sharp & Dohme Corp: Consultancy, Research Funding; AstraZeneca: Membership on an entity's Board of Directors or advisory committees, Research Funding; Acerta Pharma BV: Research Funding; Ayala (spouse): Research Funding; Bristol-Myers Squibb (spouse): Research Funding; Seattle Genetics: Research Funding; Portola Pharmaceuticals: Research Funding. Till:Mustang Bio: Patents & Royalties, Research Funding. Fromm:Merck, Inc.: Research Funding. Shustov:Seattle Genetics, Inc.: Research Funding. OffLabel Disclosure: Pembrolizumab for the treatment of indolent non-Hodgkin lymphoma

Background: Because infections are a major cause of morbidity and mortality after AML induction chemotherapy, patients typically remain hospitalized for monitoring and rapid antimicrobial therapy until hematopoietic recovery. With declining early mortality and improved oral antimicrobials, interest in moving post-induction care to the outpatient setting has emerged. In the 5-year period since completing a prospective phase 2 trial evaluating an Early Hospital Discharge (EHD) strategy, EHD following AML-like induction chemotherapy has become routine at our institution. In recent retrospective analyses, we found >80% of EHD patients required hospital readmission, primarily for neutropenic fever. Still, the EHD strategy was safe and reduced healthcare resource utilization, and EHD patients spent >70% of their post-chemotherapy time as outpatients. Here, we investigated differences in the pattern of infectious complications between patients managed as outpatients following induction chemotherapy and those who remain hospitalized until hematopoietic recovery. Methods: We retrospectively identified all adults ≥18 years with untreated AML/high-grade myeloid neoplasms (≥10% blasts in blood/ bone marrow) who started intensive induction chemotherapy ("7+3" or a regimen of similar/higher intensity) at our institution from 8/1/2014-7/31/2018. Patients were considered "EHD" if they were discharged from the hospital Results: We identified 354 inductions that met our criteria: 215 (61%) in the EHD group and 139 (39%) in the control group (baseline characteristics in Table 1). For antimicrobial prophylaxis, more EHD patients than controls used levofloxacin vs. other agents (98% vs. 93%; p=0.03) and controls more likely used posaconazole vs. EHD patients (64% vs. 52%; p Conclusion: An EHD care strategy following AML-like induction chemotherapy is associated with a higher rate of infection but not an increased risk for ICU stay or early death. Central catheter type, specifics of antimicrobial prophylaxis, and distance to our institution were not associated with infection risk in the EHD group. Further investigation to elucidate the risk factors for the increased rate of infection in the EHD group is warranted. Disclosures Halpern: Pfizer Pharmaceuticals: Research Funding; Bayer Pharmaceuticals: Research Funding. Othus:Glycomimetics: Other: Data Safety and Monitoring Committee; Celgene: Other: Data Safety and Monitoring Committee. Buckley:CTI Biopharma: Employment. Percival:Pfizer Inc.: Research Funding; Nohla Therapeutics: Research Funding; Genentech: Membership on an entity's Board of Directors or advisory committees. Becker:The France Foundation: Honoraria; Accordant Health Services/Caremark: Consultancy; AbbVie, Amgen, Bristol-Myers Squibb, Glycomimetics, Invivoscribe, JW Pharmaceuticals, Novartis, Trovagene: Research Funding. Scott:Incyte: Consultancy; Novartis: Consultancy; Agios: Consultancy; Celgene: Consultancy. Oehler:Pfizer Inc.: Research Funding; Blueprint Medicines: Consultancy; NCCN: Consultancy. Gernsheimer:Bioverativ: Consultancy; Novartis: Honoraria; Dova pharmaceuticals: Consultancy; Shionogi: Consultancy; Rigel: Consultancy; Fuji film: Consultancy; Amgen: Consultancy, Honoraria; Cellphire: Consultancy. Orozco:Actinium Pharmaceuticals: Research Funding. Cassaday:Seattle Genetics: Other: Spouse's disclosure: employment, stock and other ownership interests; Amgen: Consultancy, Research Funding; Merck: Research Funding; Seattle Genetics: Research Funding; Pfizer: Consultancy, Honoraria, Research Funding; Incyte: Research Funding; Kite/Gilead: Research Funding. Shustov:Seattle Genetics, Inc.: Research Funding. Hartley:Pfizer Inc.: Employment, Equity Ownership. Welch:Pfizer Inc: Employment, Equity Ownership. Walter:Seattle Genetics: Research Funding; Jazz Pharmaceuticals: Consultancy; Amphivena Therapeutics: Consultancy, Equity Ownership; Agios: Consultancy; Amgen: Consultancy; Aptevo Therapeutics: Consultancy, Research Funding; Argenx BVBA: Consultancy; Astellas: Consultancy; BioLineRx: Consultancy; BiVictriX: Consultancy; Boehringer Ingelheim: Consultancy; Daiichi Sankyo: Consultancy; New Link Genetics: Consultancy; Pfizer: Consultancy, Research Funding; Kite Pharma: Consultancy; Covagen: Consultancy; Boston Biomedical: Consultancy; Race Oncology: Consultancy.

Background: Current treatment of advanced stage Mycosis fungoides (MF) and Sézary syndrome (SS) remains unsatisfactory. Complete responses (CR) are typically Methods: This single-arm, multicenter study by the Cancer Immunotherapy Trials Network (CITN) enrolled 24 patients with MF/SS stages IB-IV, with at least one prior systemic therapy. Pembrolizumab was administered at 2 mg/kg every 3 weeks for up to two years. The primary endpoint was overall response rate (ORR) using global response criteria according to the ISCL/EORTC consensus guidelines. Skin responses were measured by mSWAT. Secondary endpoints were safety/tolerability, time to response (TTR), duration of response (DOR) and progression-free survival (PFS). Correlative studies included immunohistochemistry (IHC), mass cytometry, whole exome sequencing, gene expression profiling, and serum cytokine analysis. Results: Patients had advanced stage disease (23/24 with stage IIB-IV MF/SS), and were heavily pretreated (median of 4 prior systemic therapies). The ORR was 38% with 2 CR and 7 PR. Of the 9 responding patients, 6 had ≥90% improvement in skin disease by mSWAT. The median TTR was 11 weeks. Responses were durable, with 8 of 9 responses ongoing at last follow up (median DOR 64 weeks, range 32-153 weeks). One responding patient progressed 2 months after discontinuing treatment due to an adverse event (AE). The median PFS was not reached. Overall, the toxicity profile was similar to prior studies of pembrolizumab. Four patients discontinued treatment due to treatment related serious AEs of duodenitis, pneumonitis, hepatitis, and corneal ulcer. Skin flare reactions were observed early in the treatment course in 40% of patients with SS, but none with MF. The skin flare reactions did not result in any treatment discontinuation, and did not correlate with subsequent response to treatment. There was no significant association between response and clinical characteristics including stage, disease type (MF vs. SS), or number of prior therapies. IHC assessment of PD-1, PD-L1, and PD-L2 did not predict response. Treatment resulted in an increase of PD-L1 expression by both IHC and nanoString analysis. A nanoString18 gene signature of tumor inflammation that is predictive of response to pembrolizumab in other tumor types was not predictive in this cohort. High dimensional mass cytometry enabled precise identification and phenotyping of malignant T cells. There was a positive correlation between PD-1 expression on the malignant T cells and development of the skin flare reaction. Whole exome sequencing revealed genomic disruptions of PD-1 signaling including copy loss of PD-1. No associations were found between outcomes and genomic events involving the PD1/PD-L1 axis, total mutation number, or neoantigen numbers. Conclusions: The 38% ORR rate in this heavily pretreated population was 38% with a highly encouraging DOR of 64 weeks. No predictive biomarkers have emerged thus far, but additional studies are ongoing. Additional combination studies with pembrolizumab are warranted to improve response rates. Figure. Figure. Disclosures Khodadoust: Innate Pharma: Research Funding. Porcu:Innate Pharma: Consultancy. Foss:Miragen: Consultancy, Speakers Bureau; Seattle genetics: Consultancy; Spectrum: Consultancy; Mallinkrodt: Consultancy. Moskowitz:Bristol Myers-Squibb: Consultancy, Research Funding; Seattle Genetics: Consultancy, Honoraria, Research Funding; Incyte: Research Funding; Merck: Research Funding; Takeda: Honoraria; ADC Therapeutics: Research Funding. Shustov:Seattle Genetics: Research Funding. Sokol:Seattle Genetics: Consultancy; Mallinckrodt Pharmaceuticals: Consultancy; Spectrum Pharmaceuticals: Consultancy. Yearley:Merck: Employment. Horwitz:Mundipharma: Consultancy; Celgene: Consultancy, Research Funding; Seattle Genetics: Consultancy, Research Funding; ADC Therapeutics: Consultancy, Research Funding; Kyowa-Hakka-Kirin: Consultancy, Research Funding; Forty Seven: Consultancy, Research Funding; Millennium/Takeda: Consultancy, Research Funding; Infinity/Verastem: Consultancy, Research Funding; Aileron Therapeutics: Consultancy, Research Funding; Portola: Consultancy; Trillium: Consultancy; Innate Pharma: Consultancy; Spectrum: Research Funding; Corvus: Consultancy. Kim:miRagen: Research Funding; Horizon Pharma: Consultancy, Research Funding; Neumedicine: Consultancy, Research Funding; Takeda: Membership on an entity's Board of Directors or advisory committees, Research Funding; Galderma: Research Funding; Soligenix: Research Funding; Eisai: Membership on an entity's Board of Directors or advisory committees, Research Funding; Tetralogic: Research Funding; Seattle Genetics: Membership on an entity's Board of Directors or advisory committees; Portola: Research Funding; Merck: Research Funding; Medivir: Membership on an entity's Board of Directors or advisory committees; Kyowa-Kirin-Pharma: Membership on an entity's Board of Directors or advisory committees, Research Funding; Innate Pharma: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Forty Seven Inc: Research Funding.

Background: Rituximab with cyclophosphamide, doxorubicin, vincristine, and prednisone (RCHOP) remains standard therapy for previously untreated diffuse large B-cell lymphoma (DLBCL). However, a substantial proportion of patients (pts) will relapse. The anti-PD-1 monoclonal antibody pembrolizumab has shown modest efficacy in previously treated DLBCL. We postulated that the first-line setting, with relatively intact host immunity and coexistence of malignant cells with T-cells in the microenvironment, may represent an opportunity for effective immune checkpoint inhibition. We carried out the first known prospective trial of anti-PD1 therapy with anthracycline chemotherapy in lymphoma, to evaluate the safety of this combination. Methods: Pts age 18 years or older with previously untreated DLBCL, transformed lymphoma and grade 3B follicular lymphoma with a plan for 6-cycle, curative-intent RCHOP were eligible. Steroids within 7 days of treatment, active autoimmune disease, or history of pneumonitis were excluded. This phase I study combined pembrolizumab (200 mg IV q 3 weeks x 6) to RCHOP x 6, with supportive care per standard practice. A 30-pt sample size permitted estimation of the rate of clinically relevant grade 3-5 toxicity, assumed to occur in 40% of pts with RCHOP alone. A stopping rule for more than 3 instances of non-relapse death or inability to complete 6 cycles of RCHOP for any reason was applied. Secondary endpoints included response rates, overall (OS) and progression-free survival (PFS). Baseline PDL1 expression was analyzed centrally (Merck/Qualtek). Peripheral blood flow cytometry for changes in PD1, PDL-1, and PDL-2 subsets were performed. After PET-based response assessment, pts were followed for relapse and survival. Results: Since March 2016, 29 pts were treated on study; 28 have finished all therapy. One is currently on therapy, and 1 remains to be enrolled. Pt characteristics are in Table 1. In 29 pts to date, 18 grade 3-5 clinically significant AE's occurred in 13 unique pts (13/29, 45%). 16 SAE's occurred in 11 pts (11/29, 38%); none qualified as unanticipated events. Two deaths occurred: One in the first accured patient, who had extensive gastric involvement by DLBCL, and died during cycle 1 of bleeding from the responding tumor bed despite maximal inpatient intervention. The other death occurred due to steroid-refractory GVHD after haploidenticial allogeneic transplant for relapsed disease. Four immune-related adverse events (IRAE) occurred: grade 3 rash, resolving with oral steroids and not recurring with further pembrolizumab, grade 1 hyperthyroidism, grade 2 colitis, and 1 episode of grade 3 pneumonitis. This case of pneumonitis was the only immune-related SAE, occurring in a 78 yo with a history of tobacco use and COPD, and resulted in stopping therapy after cycle 3. Among 27 completing treatment (excluding the pt who died during cycle 1), average anthracycline dose was 95% of expected; anthracycline relative dose intensity (RDI: delivered dose intensity/standard dose intensity) was 94%. PET response assessment among 26 evaluable pts showed 18 CR (69%), 7 PR, and 1 primary refractory disease. Among 7 PR, 1 relapsed, 3 had negative biopsies, and 3 remain in remission. Median follow-up of survivors is 13 months and 2 relapses (1 primary progressive disease, 1 after PET PR) occurred. One-year PFS is 87% (Figure 1). Baseline PDL-1 staining available for 19 pts showed a median % tumor cell staining of 30% (moderate 2+ plus strong 3+ staining; range, 0-100%). Tumor PDL1 was ≤5% in 4, 10-29% in 5, 30-49% in 4, and ≥50% in 6 pts. Both EBV+ DLBCL had 60% tumor PDL1 expression. 1 relapsing pt had no detectable tumor PDL1, and the THRLBL failed for technical reasons. Conclusions: RCHOP with pembrolizumab 200 mg q 3 weeks x 6 cycles is safe, with toxicity similar to RCHOP alone and only 4 IRAE's. Anthracycline dose intensity, CR rate, and PFS are favorable. PDL1 tumor cell expression of 10% or more was observed in 15/19 pts. These data support further study of pembrolizumab with chemotherapy in untreated lymphoid malignancies. Final response/progression, correlative studies, and survival data will be presented in December after final accrual. Disclosures Smith: Merck Sharp and Dohme Corp.: Consultancy, Research Funding; Pharmacyclics: Research Funding; Portola Pharmaceuticals: Research Funding; Acerta Pharma BV: Research Funding; Genentech: Research Funding; Seattle Genetics: Research Funding; Incyte Corporation: Research Funding. Lynch:Johnson Graffe Keay Moniz & Wick LLP: Consultancy; Incyte Corporation: Research Funding; Takeda Pharmaceuticals: Research Funding; T.G. Therapeutics: Research Funding; Rhizen Pharmaceuticals S.A.: Research Funding. Till:Mustang Bio: Patents & Royalties, Research Funding. Cowan:Sanofi: Research Funding; Juno Therapeutics: Research Funding; Abbvie: Research Funding; Janssen: Research Funding. Shadman:Acerta Pharma: Research Funding; Genentech: Research Funding; Verastem: Consultancy; Gilead Sciences: Research Funding; Qilu Puget Sound Biotherapeutics: Consultancy; Celgene: Research Funding; Genentech: Consultancy; Beigene: Research Funding; Pharmacyclics: Research Funding; AbbVie: Consultancy; Mustang Biopharma: Research Funding; TG Therapeutics: Research Funding; AstraZeneca: Consultancy. Shustov:Seattle Genetics: Research Funding. Cassaday:Amgen: Consultancy, Research Funding; Incyte: Research Funding; Seattle Genetics: Other: Spouse Employment, Research Funding; Merck: Research Funding; Jazz Pharmaceuticals: Consultancy; Adaptive Biotechnologies: Consultancy; Pfizer: Consultancy, Research Funding; Kite Pharma: Research Funding. Gopal:Pfizer: Research Funding; Janssen: Consultancy, Research Funding; BMS: Research Funding; Takeda: Research Funding; Incyte: Consultancy; Spectrum: Research Funding; Gilead: Consultancy, Research Funding; Merck: Research Funding; Aptevo: Consultancy; Asana: Consultancy; Seattle Genetics: Consultancy, Research Funding; Brim: Consultancy; Teva: Research Funding.

Background: Chemorefractory diffuse large B-cell lymphoma (DLBCL) is associated with poor outcomes. Recent Car-T therapy trials, including Zuma-1 which led to the first FDA approval of Car-T for DLBCL (Neelapu NEJM), have shown sustained complete remission, disease control, and long-term survival in a proportion of patients. As with all trials, results must be interepreted in context of study definitions and eligibility parameters. While selection bias is often discussed, little published data regarding specific eligibility requirements on accrual of DLBCL trials exists. To better understand factors influencing Car-T trial eligibility in DLBCL, and context for observed survival rates in Car-T trials, we examined chemorefractory DLBCL patients seen from 2011-2015 at our center, applying key eligibility criteria from Zuma-1 and describing likely reasons for trial exclusion. Methods: Pts with DLBCL seen at our institution from 2011-2015, who had received at least 2 lines of therapy, were reviewed under IRB approval to determine chemorefractory status based on ZUma-1 definition, and potential eligibility for the Zuma-1 trial. Chemorefractory status per Zuma 1 was defined as stable disease (lasting 6 months or less) or progressive disease as best response to most recent chemotherapy, or disease progression within 12 months of autologous stem cell transplant. "Chemorefractory date" was identified by the chart reviewed, based on biopsy or imaging showing progression, and served as the reference date for reviewing potential Zuma-1 eligibility in detail. Specifically, clinical data (ECOG, labs, organ function) within 8 weeks of chemorefractory date was examined to estimate potential Zuma-1 eligibility. On occasion, more remote studies (e.g., an echocardiogram >8 weeks prior) were applied when data appeared relevant. Descriptive statistics and a Kaplan-Meier survival estimate were performed, with a comparison between those potentially Zuma-1 eligible and those not. No attempt was made to compare outcomes among pts receiving specific therapies for chemorefractory DLBCL. The specific eligibility factors examined were: histology (DLBCL, PMBCL and tFL); prior therapy including history of allogeneic SCT; CNS involvement, performance status (ECOG 01- vs 2 or higher), laboratory parameters, cardiac disease, infectious comorbidities; history of second malignancy other than nonmelanoma skin cancer/in situ cance or FL; need for urgent therapy due to tumor mass effect or rapid progression. Results: Of 404 in our DLBCL database from 2011-2015, 163 had received at least 2 therapies and were examined. 36 had inadequate follow up, leaving 127 for detailed analysis. Of these 127, 78 were determined chemorefractory as per Zuma-1. Of these 78 chemorefractory pts, median age was 63 (18-82), 17 had transformed lymphoma, 30 underwent transplant (20 auto, 2 allo, 8 auto-allo), 18 relapsed within 1 year of autologous transplant, and 30 had primary refractory disease. 43 patients (55%) were deemed ineligible for Zuma-1 by retrospective review, for reasons given in Table 1. Figure 1 shows survival. Among "eligible" pts vs not: Median OS was 15 vs 8 months (eligible vs not, p=.04). 1 yr OS was 56% vs 33%, and 2 yrs OS 40% vs 22%. Conclusion: When applied to a historical cohort, about half of chemorefractory DLBCL pts met eligibility criteria for Zuma-1. The survival of "eligible" patients appears significantly better than others. A need for acute therapy (for rapid progression), ECOG performance status 2 or greater, and non-FL transformation (Richter's/CLL history) were the most common reasons for exclusion. Since these three features may not impact safety of Car-T therapy, but are associated with agrgessive disease, broadening eligibility around these criteria could represent a step toward testing Car-T therapies among those with greatest unmet need. Disclosures Lynch: T.G. Therapeutics: Research Funding; Rhizen Pharmaceuticals S.A.: Research Funding; Incyte Corporation: Research Funding; Takeda Pharmaceuticals: Research Funding; Johnson Graffe Keay Moniz & Wick LLP: Consultancy. Shadman:TG Therapeutics: Research Funding; AstraZeneca: Consultancy; Genentech: Research Funding; Verastem: Consultancy; Mustang Biopharma: Research Funding; Celgene: Research Funding; Gilead Sciences: Research Funding; AbbVie: Consultancy; Qilu Puget Sound Biotherapeutics: Consultancy; Acerta Pharma: Research Funding; Pharmacyclics: Research Funding; Genentech: Consultancy; Beigene: Research Funding. Till:Mustang Bio: Patents & Royalties, Research Funding. Shustov:SPECTRUM PHARMACEUTICALS: Consultancy, Research Funding. Gopal:Janssen: Consultancy, Research Funding; Asana: Consultancy; Takeda: Research Funding; Merck: Research Funding; BMS: Research Funding; Spectrum: Research Funding; Teva: Research Funding; Pfizer: Research Funding; Seattle Genetics: Consultancy, Research Funding; Gilead: Consultancy, Research Funding; Brim: Consultancy; Aptevo: Consultancy; Incyte: Consultancy. Smith:Pharmacyclics: Research Funding; Genentech: Research Funding; Acerta Pharma BV: Research Funding; Incyte Corporation: Research Funding; Merck Sharp and Dohme Corp.: Consultancy, Research Funding; Portola Pharmaceuticals: Research Funding; Seattle Genetics: Research Funding.

Introduction: Patients with aggressive peripheral T-cell lymphoma (PTCL) often undergo induction with anthracycline-based chemotherapy followed by autologous stem cell transplantation in fit patients. Up to 40% of patients have primary refractory disease, and even for those who respond to induction, 5-year overall survival (OS) is 32% with the exception of ALCL. This results in a significant number of patients who need treatment in the relapsed and refractory (R/R) setting. While there is no standard approach for this group, multiagent chemotherapy regimens are often used, particularly in those who may be transplant candidates. Several novel single agents have shown activity in R/R PTCL and can often be given in a more continuous fashion than combination chemotherapy. In order to explore the potential benefits of single agents in comparison to combination chemotherapy in R/R PTCL, we examined treatment outcomes in a prospectively enrolled cohort of PTCL patients. Methods: Patients were enrolled in the Comprehensive Oncology Measures for Peripheral T-cell Lymphoma Treatment (COMPLETE), a multinational prospective cohort of 500 newly diagnosed PTCL patients. Demographics, treatments, and outcomes were recorded until death or for at least 5 years. Analysis was restricted to 6 subtypes of PTCL: PTCL-NOS, AITL, ALCL, EATL, NKT, HSTCL. Primary refractory was defined as lack of a complete response (CR) to initial treatment. Relapsed was defined as a CR to initial treatment with progression at a later date. Patients in whom initial treatment was ≤4 days, unreported, or began >30 days before or after informed consent were excluded. Single agents were pralatrexate, romidepsin, brentuximab vedotin (BV), bendamustine, alisertib, denileukin diftitox, and lenalidomide. Combinations were any multiagent chemotherapy regimen excluding the above agents. Results: Of 462 patients with locked records, 57 met the above eligibility criteria and had treatment and followup data available for analysis. As first treatment in R/R disease, 26 patients received combination therapy (by subtype: PTCL-NOS [10], AITL [6], ALCL [3], EATL [1], NKT [5], HSTCL [1]) and 31 received single agents (by subtype: PTCL-NOS [13], AITL [5], ALCL [7], EATL [2], NKT [2], HSTCL [2]). The most common combination regimens had an ifosfamide-, gemcitabine-, or platinum-based backbone. Single agents used were: BV (12), romidepsin (8), pralatrexate (5), alisertib (3), bendamustine (1), denileukin diftitox (1), and lenalidomide (1). The objective response rate (ORR) for single agents was higher than for combination therapy (59% [17/29] vs. 46% [12/26], P=0.36), as was the CR rate (41% [12/29] vs. 19% [5/26], P=0.02). In those with R/R ALCL who received BV, ORR was 83% (5/6) and CR was 67% (4/6). Given these expected high response rates of BV in R/R ALCL, a subtype analysis excluding ALCL patients who received BV (ALCL-BV) was conducted and showed similar ORR between single and combination therapy (52% [12/23] vs. 46% [12/26], P=0.26), though CR still favored single agents (35% [8/23] vs. 19% [5/26], P=0.07). Excluding the ALCL-BV group, CRs were observed with BV (3/6), romidepsin (2/8), pralatrexate (1/5), bendamustine (1/1), and alisertib (1/3). Median progression-free survival (PFS) favored single over combination therapy (11.2 vs. 6.7 months, P=0.02). PFS in the ALCL-BV group was comparable at 11 months. Stem-cell transplantation occurred more frequently after single agent use than combination therapy (25% [8/31] vs. 7% [2/26]). Conclusion: Our analysis confirms the unmet need for better therapies in R/R PTCL. This data shows a trend towards increased CR and PFS with single agents in comparison to combination therapy, while maintaining the potential to bridge to transplantation. It is unclear whether the differences were driven by reduced toxicity and longer treatment duration with single agents, increased efficacy from BV in CD30-expressing cancers, or patient factors that led to therapy selection. However, despite the small size and exploratory nature of this analysis, single agents do not appear inferior to combination therapy with respect to disease control or ability to bridge to transplant with intent to cure. Our data can serve as a foundation for larger datasets or randomized trials which are needed to identify the truly superior strategy. In the meantime, the optimal approach for R/R PTCL remains unclear. Disclosures Schwartz: MS Biostatistics, LLC: Employment. Acosta:Spectrum: Employment. Pro:Seattle Genetics: Consultancy, Other: Travel expenses, Research Funding; kiowa: Honoraria; portola: Honoraria; Takeda Pharmaceuticals: Honoraria, Other: Travel expenses. Shustov:Seattle Genetics: Research Funding. Horwitz:Aileron Therapeutics: Consultancy, Research Funding; Millennium/Takeda: Consultancy, Research Funding; Mundipharma: Consultancy; ADC Therapeutics: Consultancy, Research Funding; Spectrum: Research Funding; Trillium: Consultancy; Corvus: Consultancy; Forty Seven: Consultancy, Research Funding; Seattle Genetics: Consultancy, Research Funding; Celgene: Consultancy, Research Funding; Innate Pharma: Consultancy; Infinity/Verastem: Consultancy, Research Funding; Portola: Consultancy; Kyowa-Hakka-Kirin: Consultancy, Research Funding. Foss:Seattle genetics: Consultancy; Miragen: Consultancy, Speakers Bureau; Mallinkrodt: Consultancy; Spectrum: Consultancy.

BACKGROUND: HyperCVAD is used commonly in adult ALL but can be difficult for older or infirm patients (pts) to tolerate (JCO 2000, p. 547; Cancer 2008, p. 2097). At our center, only 50% who receive it reach a minimal residual disease negative (MRD-) state within 90 days (Am J Hematol 2018, p. 546). Lower-intensity options with ABL tyrosine kinase inhibitors (TKIs) yield high response rates in Philadelphia chromosome (Ph)+ disease, but long-term efficacy may be limited (Blood 2016, p. 774; ASH 2017, #99). DA-EPOCH is effective and relatively well-tolerated in high-grade lymphomas (NEJM 2013, p. 1915; Blood 2014, p. 2354). This prompted us to study DA-EPOCH as initial treatment of adult ALL. METHODS: Pts ≥ 18 years old with newly-diagnosed ALL were eligible if they were not a candidate for pediatric-inspired therapy (e.g., Ph+, age ≥ 40) and had adequate liver and kidney function. All pts signed IRB-approved consent forms. This single-center trial is registered on clinicaltrials.gov (NCT03023046) and supported by NCI 5P30 CA015704-41. DA-EPOCH was given as initially described (Blood 2002, p. 2685). Doses of myelosuppressive agents were adjusted based on the hematologic nadir after the previous cycle, but pts could start the next cycle before day 21 once ANC ≥ 1K/μL and platelets (plt) ≥ 50K/μL, and (after 1st 5 pts treated) dose-reduction was deferred if cytopenias reflected ALL. If Ph+, imatinib (IM) 600 mg or dasatinib (DAS) 100 mg daily on Days 1-14 of each cycle was added. If CD20+, rituximab (R) 375 mg/m2 was given once per cycle. All pts received G-CSF and intrathecal prophylaxis. Response was determined by morphology (morph), multiparameter flow cytometry (MFC) and (for Ph+) BCR-ABL RT-PCR on bone marrow aspirate (BMA). When MRD- by MFC (MFC-), high-throughput sequencing (HTS)-based MRD testing was performed as described previously (Clin Cancer Res 2014, p. 4540). BMA was performed after cycle 1, then repeated as needed to confirm MFC- or persistence. Up to 8 cycles could be given followed by maintenance (POMP ± TKI) or hematopoietic cell transplant (HCT) at physician's discretion, though morph CR after ≤ 2 cycles was needed to continue. The primary endpoint was rate of MFC- after ≤ 4 cycles (i.e., < 90 days), defined by EuroFlow criteria (Leukemia 2010, p. 521). Using a historical rate with hyperCVAD of 50% (cited above) and defining success if observed rate is 70%, a Simon 2-stage design with α = 0.09 and 80% power led to the following: total sample size of 28 pts, stop enrollment if ≤ 7 of 15 were MFC- after ≤ 4 cycles, and judge the regimen of interest if ≥ 18 of 28 were MFC- after ≤ 4 cycles. Follow-up provided to 7/10/18. RESULTS: 18 pts have received ≥ 1 cycle (Table). 15 (83%) achieved morph CR after ≤ 2 cycles. 8 of 14 (57%; 95% CI 0.29-0.82) evaluable for the primary endpoint were MFC- after ≤ 4 cycles; 3 pts remain too early to evaluate; 1 pt was removed after 2 cycles to continue DA-EPOCH closer to home. 2 Ph+ pts received IM, and 10 received DAS. 7 of 9 (78%) evaluable Ph+ pts were MFC- after ≤ 4 cycles, 3 after 1 cycle. 6 Ph+ pts (5 p190 and 1 p210; 67%) were MRD- by PCR after ≤ 4 cycles. 1 of 5 evaluable Ph- pts (20%) reached MFC- after 1 cycle. MRD by HTS was sought in 5 MFC- patients: clonal sequence was identifiable pre-treatment in 4, and 3 (75%) achieved MRD- by HTS, including 2 after only 1 cycle (both Ph+). 16 (89%) pts developed Grade (Gr) 3+ non-hematologic toxicity at some point throughout treatment, with febrile neutropenia (7 Gr 3), hypofibrinogenemia (4 Gr 3), and GI bleed (2 Gr 3, 1 Gr 5) the most common. 1 pt (6%) died in morph CR after Cycle 3; no other pts stopped due to toxicity. Median cycle length was 21 days (range: 16-27). Once beyond Cycle 2, only 7 of 28 total cycles (25%) yielded ANC < 500/μL for ≥ 1 week or any plt < 25K/μL (i.e., dose-reduction per the DA-EPOCH paradigm). 5 pts (28%) have undergone HCT, 3 of whom were in CR1 after DA-EPOCH (all Ph+). 5 in CR after DA-EPOCH have relapsed (33%), 1 of whom was post-HCT. No deaths from ALL have occurred. Median and 6-mo EFS are 8 mo and 61% (respectively). Median OS is not reached, and 6-mo OS is 94% (Figure). CONCLUSIONS: DA-EPOCH yields deep remissions (including by HTS) in newly-diagnosed ALL, particularly with TKI for Ph+ disease. Toxicity is manageable and rarely leads to discontinuation or delay. Because of the relatively high rate of early MFC-, the interim stopping rule for efficacy was not met, and enrollment continues. Updated results (including genomic profiling by RNAseq) will be presented. Disclosures Cassaday: Kite Pharma: Research Funding; Pfizer: Consultancy, Research Funding; Merck: Research Funding; Amgen: Consultancy, Research Funding; Incyte: Research Funding; Jazz Pharmaceuticals: Consultancy; Adaptive Biotechnologies: Consultancy; Seattle Genetics: Other: Spouse Employment, Research Funding. Shustov:Seattle Genetics: Research Funding. Becker:GlycoMimetics: Research Funding. Radich:TwinStrand Biosciences: Research Funding.

BACKGROUND: CD19-specific chimeric antigen receptor (CAR) T-cell therapy has proven to be highly effective in patients with relapsed or refractory large B-cell lymphomas, yielding early complete response (CR) rates of ~40%, which are typically sustained. Unfortunately, most patients will not experience prolonged disease control. Despite this fact, little data exist defining the outcomes and impact of subsequent therapies for such individuals. Limited data also exist on the ability for such patients to pursue further clinical trials or allogeneic hematopoietic stem-cell transplant (HSCT). This project details the specific interventions and outcomes of this population to better inform the management of patients who suffer progressive disease (PD) after CD19-specific CAR T-cell therapy. METHODS: Adults with diffuse large B-cell lymphoma (DLBCL), transformed follicular lymphoma (tFL), primary mediastinal B-cell lymphoma (PMBCL), and high-grade B-cell lymphomas (HGBCL) who received CD19-specific CAR T-cells at the University of Washington/Seattle Cancer Care Alliance were included in this analysis. Patients who received CAR T-cell therapy in conjunction with additional protocol-specified therapy were excluded. Those who exhibited PD or persistent lymphoma after CAR T-cell therapy were the focus of this study. We defined initial PD as patients who had evidence of disease progression on the initial response assessment. Delayed PD was defined as achieving a CR, partial response (PR), or stable disease (SD) on the initial response assessment, but eventually progressed or received subsequent anti-lymphoma therapy. Baseline characteristics and all data were retrieved from the electronic medical record up until date of death or date of last contact in our system, including subsequent interventions and outcomes. Primary endpoint of this analysis was overall survival (OS). RESULTS: Between October 2013 and May 2018, we identified 51 patients with PD following CD19-specific CAR T-cell therapy. Baseline characteristics are listed in the Table 1. Histologies included DLBCL (29), HGBCL (11), tFL (8) and PMBCL (3). Median age was 60 years (range 26-75), 65% were male, median prior regimens was 3 (range 1-8). Median time from CAR T infusion to PD was 42 days (range 11-609), with 27 (53%) patients exhibiting initial PD. Median follow up after time of progression was 4.2 months. Initial PD was associated with a higher risk of death (HR 2.376, 95% CI 1.19-4.75, p=0.0143, Figure 1). The median OS for those with initial PD and delayed PD was 5.1 months (95% CI 2.0-9.3) and 13.6 months (4.1-not reached) respectively. 39 (76%) patients received ≥ 1 subsequent therapies after PD. Initial therapies included: 2nd CAR T infusion (14), targeted therapy (10), chemotherapy +/- rituximab (7), other immunotherapy (3), radiotherapy (3), intrathecal chemotherapy (1) and allogeneic HSCT (1). 12 (24%) patients received no further therapy despite PD. Those who received ≥ 1 subsequent therapies after PD had a lower risk of death (HR 0.344, 95% CI 0.149-0.793, P=0.0122) compared to those who did not. There was no difference in survival if 2nd CAR T infusion was the next line therapy compared to others (p=0.449), targeted therapy compared to others (p=0.417), or chemotherapy compared to others (p=0.565). 5 (10%) patients enrolled onto a clinical trial as next line therapy. 4 (8%) patients eventually received an allogeneic HSCT after PD, 2 of whom are still alive. We identified 8 patients who were alive for ≥ 12 months after progression without evidence of lymphoma. Last line of therapy for these patients included allogeneic HSCT (2), subsequent CD19-specific CAR-T cell infusion (2), ibrutinib (2), lenalidomide/rituximab (1), and radiotherapy (1). CONCLUSIONS: Patients with PD post anti-CD19 CAR T-cell therapy, particularly those exhibiting initial PD, have poor long-term outcomes. Patients receiving at least one anti-lymphoma therapy after PD had improved overall survival, although no single approach appeared to confer a survival benefit. Few enrolled onto a clinical trial or received an allogeneic HSCT. These data reinforce the need to both further improve the durable CR rate after CAR T-cell therapy and to develop effective strategies for those not achieving a CR. Figure 1 Figure 1. Disclosures Gopal: Spectrum: Research Funding; Pfizer: Research Funding; BMS: Research Funding; Seattle Genetics: Consultancy, Research Funding; Merck: Research Funding; Takeda: Research Funding; Brim: Consultancy; Janssen: Consultancy, Research Funding; Asana: Consultancy; Gilead: Consultancy, Research Funding; Aptevo: Consultancy; Incyte: Consultancy; Teva: Research Funding. Maloney:Juno Therapeutics: Research Funding; Roche/Genentech: Honoraria; Janssen Scientific Affairs: Honoraria; Seattle Genetics: Honoraria; GlaxoSmithKline: Research Funding. Turtle:Caribou Biosciences: Consultancy; Adaptive Biotechnologies: Consultancy; Nektar Therapeutics: Consultancy, Research Funding; Bluebird Bio: Consultancy; Precision Biosciences: Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Juno Therapeutics / Celgene: Consultancy, Patents & Royalties, Research Funding; Eureka Therapeutics: Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Aptevo: Consultancy; Gilead: Consultancy. Smith:Genentech: Research Funding; Acerta Pharma BV: Research Funding; Incyte Corporation: Research Funding; Merck Sharp and Dohme Corp.: Consultancy, Research Funding; Pharmacyclics: Research Funding; Portola Pharmaceuticals: Research Funding; Seattle Genetics: Research Funding. Shadman:TG Therapeutics: Research Funding; Mustang Biopharma: Research Funding; Acerta Pharma: Research Funding; AstraZeneca: Consultancy; Verastem: Consultancy; Gilead Sciences: Research Funding; AbbVie: Consultancy; Qilu Puget Sound Biotherapeutics: Consultancy; Beigene: Research Funding; Genentech: Research Funding; Pharmacyclics: Research Funding; Genentech: Consultancy; Celgene: Research Funding. Cassaday:Seattle Genetics: Other: Spouse Employment, Research Funding; Incyte: Research Funding; Jazz Pharmaceuticals: Consultancy; Pfizer: Consultancy, Research Funding; Kite Pharma: Research Funding; Merck: Research Funding; Amgen: Consultancy, Research Funding; Adaptive Biotechnologies: Consultancy. Till:Mustang Bio: Patents & Royalties, Research Funding. Shustov:Seattle Genetics: Research Funding. Acharya:Juno Therapeutics: Research Funding; Teva: Honoraria. Lynch:Takeda Pharmaceuticals: Research Funding; T.G. Therapeutics: Research Funding; Rhizen Pharmaceuticals S.A.: Research Funding; Johnson Graffe Keay Moniz & Wick LLP: Consultancy; Incyte Corporation: Research Funding.

Background: A frequent complication of Pralatrexate therapy is development of oral mucositis. In a recent pivotal trial of pralatrexate (PROPEL, O'Connor et al. J Clin Onc 2011) the incidence of ≥ Grade 2 mucositis was 52%, occurring primarily in the first treatment cycle. Mucositis often leads to dose reduction or omission and possibly, diminished efficacy of pralatrexate in relapsed/refractory (R/R) PTCL. Leucovorin (d,l-folinic acid) is an approved rescue therapy for high-dose methotrexate (MTX) therapy, mitigating gastrointestinal lining, and bone marrow cell toxicity and has been used adjunctively with pralatrexate to manage mucositis. The objective of this prospective Phase 2, single-arm study was to evaluate the effect of leucovorin on the incidence of pralatrexate-induced mucositis in patients with R/R PTCL, including primary cutaneous T-cell lymphomas. Methods: Eligible patients had diagnosis of PTCL, including CTCL, confirmed by local hematopathologist or dermatopathologist and were deemed appropriate for pralatrexate therapy by investigator. Study treatment consisted of two cycles of Pralatrexate, (6 weekly doses (30 mg/m2) followed by 1 week of rest per cycle, currently approved label). All patients received vitamin B12 and folic acid supplementation; oral leucovorin, 25 mg TID was self-administered for 2 consecutive days (a total of 6 doses) beginning 24 hours after each dose of Pralatrexate. Patients underwent in-clinic oral mucositis assessment at baseline and at each visit prior to pralatrexate administration by healthcare professional. Patients also completed a daily oral mucositis questionnaire (OMDQ) from Day 1 of Cycle 1 to the end of treatment visit. Mucositis was assessed by the investigator and recorded as an AE along with grade and causality. Toxicities were assessed using Common Terminology Criteria (CTCAE V4.03). Responses were assessed by the investigator per revised Response Criteria for Malignant Lymphoma (Cheson 2007) and Modified SWAT Criteria for CTCL.The primary endpoint was the incidence of Grade 2 or higher oral mucositis in Cycle 1. Secondary endpoints included the incidence of ≥ Grade 3 mucositis, and overall response rate. Results: A total of 30 patients have been enrolled as of time of data analysis. The majority of patients were male, white, with the median age of 63 yrs (range, 31-85). To date (5 July 2018) 11 patients have completed the study treatment, 12 patients discontinued (1 AE, 9 PD, 1 death, and 1 withdrawal) and 7 patients remain in the trial. All 30 subjects reached the assessment of the primary endpoint. The primary endpoint of the study has been met. Twenty (67%) patients have reported TEAEs, of which 11 (37%) have been ≥Grade 3 AEs. Overall toxicity profile was consistent with previously reported in the PROPEL trial. Most common Pralatrexate-related AEs were fatigue in 6 (20%) patients and diarrhea that occurred in 4 (13%) patients. SAEs occurred in 9 patients (only pyrexia in >1 pt; N=2), none were treatment-related. The rate of ≥2 mucositis was 4% (95% C.I. = 0, 20%). No Grade 3 or higher mucositis occurred; Grade 1 mucositis was observed in 4 patients. Assessment of treatment response rate (secondary endpoint) is ongoing and will be reported at the meeting. Conclusions: Overall safety profile of the study treatment was consistent with pivotal trial of Pralatrexate in R/R PTCL. Leucovorin as adjunctive treatment resulted in a significant reduction in rates of both ≥Grade 2, and ≥Grade 3 mucositis and should be considered in patients treated with Pralatrexate. Disclosures Shustov: SPECTRUM PHARMACEUTICALS: Consultancy, Research Funding. Bhat:SPECTRUM PHARMACEUTICALS: Employment.

Background: Peripheral T-cell lymphomas (PTCL) are a rare and heterogeneous group of NHL with poor prognosis. Frontline therapy yields a 50-70% overall response rate, but the majority of pts will relapse, which translates to poor overall survival. ALRN-6924, the first-in-class clinical stage stapled peptide, has been structurally stabilized ("stapled") in an α-helical configuration, to mimic the inhibitor-binding region of the tumor suppressor protein, p53. By mimicking this region, ALRN-6924 binds the two most important endogenous inhibitors of p53, murine double minute-X (MDMX) and -2 (MDM2), thereby restoring p53's ability to induce cell cycle arrest and apoptosis in TP53 wild-type (WT) cancer cells. ALRN-6924 is the first known synthetic agent to simultaneously target both of these important p53 inhibitors. A durable CR has been reported in a pt with an angioimmunoblastic subtype of PTCL who is part of the first-in-human study of ALRN-6924 (Meric-Bernstam et al., 2017), providing the rationale for two PTCL expansion cohorts. The PTCL QW cohort is receiving treatment at the recommended Phase 2 dose (QWx3 every 28 days). Preclinical data suggest that more frequent dosing may enhance efficacy (Carvajal et al., 2018; Ng et al., 2018) and this hypothesis is being evaluated in a second PTCL cohort, treated TIWx1 every 21 days. Methods: Pts with relapsed or refractory PTCL are receiving treatment with 3.1 mg/kg of ALRN-6924 IV over 1 hour, on Days 1, 8, and 15 of a 28-day cycle (QW) or Days 1, 3, and 5 of a 21-day cycle (TIW). Treatment continues until symptomatic progressive disease (PD), unacceptable toxicity, or other indication for treatment withdrawal. Due to documented cases of pseudoprogression, continuation beyond radiographic PD is permitted at the investigator's discretion. Response is evaluated by investigators according to IWG 2014. Additionally, an independent radiologist reviews response using IWG 2014 and modified Cheson 2007. Adverse events (AEs) are assessed per CTCAE V4.03. Results: As of 13 July 2018, 26 PTCL pts have been treated (16 QW, including one from Phase 1, 10 TIW) with a median age of 63 years (31-82). Here, we report safety from the QW and TIW cohorts as well as efficacy from the QW cohort. Accrual to TIW continues; its efficacy data as well as updated safety data will be presented at the meeting. Median number of prior systemic therapies is 3 (1-10). Pts have received 1-34 cycles. Of the 16 QW-pts and 10 TIW-pts, 2 and 6 pts remain on therapy, respectively. Treatment-related AEs have been reported in 76.9% of 26 PTCL pts dosed QW or TIW. Fatigue (50.0%), nausea (42.3%), anemia (19.2%), diarrhea (15.4%), headache (15.4%), vomiting (15.4%), and hyperbilirubinemia (11.5%) are most frequent. 46.2% have experienced grade 3 AEs, most commonly fatigue (7.7%), anemia (7.7%), and hyperbilirubinemia (7.7%). No related grade 4 or 5 AEs have been reported. SAEs have been reported in 10 pts, including 3 treatment-related SAEs: a grade 3 lung infection, a grade 3 nausea/vomiting, and a grade 3 hyperbilirubinemia, which is a known transient effect of ALRN-6924 and has not been associated with liver injury. Treatment has been discontinued due to related AEs in 2 pts, for a grade 1 infusion-related reaction and a grade 3 lung infection (pneumonia). Main reasons for treatment discontinuation include disease progression (46.1%; objective PD 19.2%, clinical PD 26.9%) and AE (7.7%). Pts receiving QW treatment who received at least one dose of ALRN-6924, had TP53 WT, and a post-baseline assessment or evidence of clinical disease progression were evaluated for efficacy. Table 1 shows responses determined by IWG 2014 (investigator-reported) and modified-Cheson 2007 (independent radiologist-determined) for the evaluable QW patients. One pt was not evaluable per IWG 2014. Cases of pseudoprogression during treatment of PTCL pts with ALRN-6924 have been documented. Several pts with new FDG-avid lesions and/or transient lymph node enlargement on CT have benefitted from treatment continuation, including pts who went on to achieve a subsequent response. Conclusion: ALRN-6924 has shown activity against PTCL and has an acceptable safety profile across QW and TIW dosing. The potential for pseudoprogression was not initially recognized, hence raising the possibility that the true response rate for QW may be higher. These early data support continued development of ALRN-6924 for the treatment of PTCL. Disclosures Shustov: Seattle Genetics: Research Funding. Horwitz:Celgene: Consultancy, Research Funding; Forty Seven: Consultancy, Research Funding; Infinity/Verastem: Consultancy, Research Funding; Seattle Genetics: Consultancy, Research Funding; Mundipharma: Consultancy; Kyowa-Hakka-Kirin: Consultancy, Research Funding; Spectrum: Research Funding; Millennium/Takeda: Consultancy, Research Funding; ADC Therapeutics: Consultancy, Research Funding; Portola: Consultancy; Aileron Therapeutics: Consultancy, Research Funding; Innate Pharma: Consultancy; Trillium: Consultancy; Corvus: Consultancy. Sokol:Seattle Genetics: Consultancy; Mallinckrodt Pharmaceuticals: Consultancy; Spectrum Pharmaceuticals: Consultancy. Meric-Bernstam:Genentech: Consultancy; Inflection Biosciences: Consultancy; Pieris Pharmaceuticals: Consultancy; Clearlight Diagnostics: Consultancy; Darwin Health: Consultancy; Bioepis: Consultancy; Novartis: Research Funding; AstraZeneca: Research Funding; Taiho Pharmaceuticals: Research Funding; Genentech: Research Funding; Calithera Biosciences: Research Funding; Debiopharm: Research Funding; Bayer: Research Funding; Aileron Therapeutics: Research Funding; PUMA Biotechnology: Research Funding; CytomX Therapeutics: Research Funding; Zymeworks: Research Funding; Curis: Research Funding; Pfizer: Research Funding; eFFECTOR Therapeutics: Research Funding; Abbvie: Research Funding; Sumitomo Group: Honoraria; Dialecta: Honoraria. Shapiro:Roche: Membership on an entity's Board of Directors or advisory committees; Merck/EMD Serono: Research Funding; G1 Therapeutics: Membership on an entity's Board of Directors or advisory committees; Merck/EMD Serono: Membership on an entity's Board of Directors or advisory committees; Pfizer: Research Funding; Lilly: Membership on an entity's Board of Directors or advisory committees; Pfizer: Membership on an entity's Board of Directors or advisory committees; Sierra Oncology: Research Funding; Lilly: Research Funding. Dwivedy Nasta:Roche: Research Funding; Takeda/Millenium: Research Funding; Aileron: Research Funding; Rafael/WF: Research Funding; Merck: Other: DSMC; Debiopharm: Research Funding; Pharmacyclics: Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees; Incyte: Research Funding. Janakiram:Seattle Genetics: Membership on an entity's Board of Directors or advisory committees. Weinstock:Novartis, Astra Zeneca, Abbvie, Aileron, Surface Oncology, Daiichi Sankyo: Research Funding; Novartis: Consultancy, Research Funding; Genentech/Roche, Monsanto: Consultancy; Novartis, Dragonfly, Travera, DxTerity, Travera: Consultancy; Travera: Equity Ownership; Astra Zeneca, JAX, Samumed, Regeneron, Sun Pharma, Prescient: Patents & Royalties. Korn:Imaging Endpoints: Employment, Equity Ownership; Aileron Therapeutics Inc.: Other: Client. Payton:Aileron Therapeutics: Employment, Equity Ownership. Annis:Aileron Therapeutics Inc.: Employment, Equity Ownership, Patents & Royalties. Pinchasik:Aileron Therapeutics Inc.: Employment, Equity Ownership. Aivado:Aileron Therapeutics Inc.: Employment, Equity Ownership, Patents & Royalties. Mehta:Kite: Consultancy, Speakers Bureau; Celgene: Consultancy; Spectrum: Consultancy; Bristol-Myers Squibb: Consultancy, Research Funding; F. Hoffmann-La Roche Ltd: Research Funding; Incyte: Research Funding; Merck: Research Funding; Gilead: Consultancy, Speakers Bureau; Epizyme: Research Funding; Seattle Genetics: Research Funding; AstraZeneca: Consultancy, Speakers Bureau; Carevive: Other: Patient engagement; Medpage: Other: Medical website.

Background: ALRN-6924, an α-helical stapled p53 peptide, is the first-in-class and only dual inhibitor of MDMX and MDM2 currently in clinical trials for both, solid and hematologic malignancies. In tumors with wild-type (WT) TP53, ALRN-6924 can induce p53-dependent cell cycle arrest and apoptosis and separately can invoke p53-mediated immunomodulatory effects, including but not limited to lymphocyte chemotaxis and diminution of PD-L1 expression on tumor cells. This report begins to describe the biologic underpinnings of PsP in selected PTCL patients (pts) treated with ALRN-6924. Despite imaging-based progressive disease (PD), careful monitoring for clinical benefit in light of conflicting imaging (PsP) results led to the decision to treat beyond radiologic progression and the observation of subsequent, delayed radiologic responses. Methods: Pts with relapsed or refractory PTCL received either 3.1 mg/kg ALRN-6924 on days 1, 8, and 15 of a 28-day cycle (QW) or Days 1, 3, and 5 of a 21-day cycle (TIW). Responses were assessed locally using IWG 2014 criteria as well as through independent radiology assessment. Treatment continued until symptomatic PD, unacceptable toxicity, or other indication for withdrawal. Continuation beyond radiologic PD was permitted for perceived clinical benefit. RNA-based immune profiles from pre- and post-treatment tumor biopsies from pts who were treated with ALRN-6924 were evaluated by gene expression panels. Clinical findings were correlated with CT26 and MC38 murine syngeneic tumor models, where immune cell infiltration after ALRN-6924 dosing was measured by flow cytometry. Results: PsP was observed in 3 PTCL pts who eventually achieved a PR. A pattern of transient tumor flare and new lesion formation was noted in one pt (pt 13-196) while the other 2 PsP pts (pt 3-159 and 11-155) had atypical PsP patterns, including tumor shrinkage by CT, but transient new and/or increased 18Fluorodeoxyglucose (FDG)-PET uptake. In one pt, there was rapid clinical improvement of malignant hypercalcemia and B symptoms despite formal IWG 2014 progression after 2 cycles of ALRN-6924 QW treatment plus an additional transient episode of PsP due to new FDG-avid lesions at cycle 8. Another pt had a similar PsP pattern with decrease in lesion size on CT but increased FDG-avidity of target lesions following 2, 4, and 6 cycles of QW-therapy with ALRN-6924, with new FDG-avid lesions that appeared, and then resolved in different anatomical locations at each imaging assessment. Local pathology reported findings consistent with PTCL upon post-baseline biopsy of one of these lesions. Pre- and post-baseline biopsies were analyzed for differences in RNA-expression of immune-related genes, and showed changes consistent with p53-mediated immunomodulatory effects. Despite formal progression due to transient PET-avid lesions, both pts remained on therapy, subsequently achieving a confirmed PR. A pt treated with TIW ALRN-6924 (pt 13-196) exhibited worsening abdominal pain by Day 5 of ALRN-6924, with CT scans on days 6, 11, and 22 showing transient enlargement and increased number of nodes, splenomegaly, and ascites, consistent with progression. The pt continued therapy with resolution of clinical symptoms, and an efficacy assessment after 3 cycles showed dramatic reduction in lesion sizes and FDG-avidity, assessed as a PR (unconfirmed). Preclinically, in mice treated with ALRN-6924, a significant increase in tumor-infiltrating CD8+ T cells and M1-polarized macrophages was found in murine TRP53-WT CT26 tumors as well as in TRP53-mutant MC38 tumors. Conclusion: Treatment of PTCL with ALRN-6924 can be associated with PsP. Pts have benefitted from treatment beyond radiologic progression, with new FDG-avid lesions resolving over time. Murine tumor models plus changes in immune-related gene expression in pre- and post-baseline tumor samples from pts suggest that p53-mediated immune-activation may account for these findings. Transient tumor flare observed in pts, was consistent with increased immune cell infiltration that was detected after p53-activation in the tumor microenvironment of TRP53-mutant syngeneic models. ALRN-6924 is a promising anticancer agent that warrants further investigation and consideration should be given to possible pseudoprogression prior to discontinuing pts from treatment with ALRN-6924. Disclosures Shustov: Seattle Genetics: Research Funding. Mehta:Spectrum: Consultancy; Gilead: Consultancy, Speakers Bureau; Incyte: Research Funding; Bristol-Myers Squibb: Consultancy, Research Funding; Kite: Consultancy, Speakers Bureau; Celgene: Consultancy; F. Hoffmann-La Roche Ltd: Research Funding; Merck: Research Funding; Epizyme: Research Funding; Seattle Genetics: Research Funding; AstraZeneca: Consultancy, Speakers Bureau; Carevive: Other: Patient engagement; Medpage: Other: Medical website. Sokol:Mallinckrodt Pharmaceuticals: Consultancy; Seattle Genetics: Consultancy; Spectrum Pharmaceuticals: Consultancy. Carvajal:Aileron Therapeutics Inc.: Employment, Equity Ownership. Guerlavais:Aileron Therapeutics Inc.: Employment, Equity Ownership, Patents & Royalties. Samant:Aileron Therapeutics Inc.: Employment, Equity Ownership, Patents & Royalties. Narasimhan:Aileron Therapeutics Inc.: Employment, Equity Ownership. Sutton:Aileron Therapeutics Inc.: Consultancy. Annis:Aileron Therapeutics Inc.: Employment, Equity Ownership, Patents & Royalties. Pinchasik:Aileron Therapeutics Inc.: Employment, Equity Ownership. Aivado:Aileron Therapeutics Inc.: Employment, Equity Ownership, Patents & Royalties. Korn:Aileron Therapeutics Inc.: Other: Client; Imaging Endpoints: Employment, Equity Ownership.

Background: The prognosis of patients with PTCL remains poor after standard CHOP therapy - the most commonly used combination regimen. Relapses occur in the majority of patients, and curability rates of the relapsed disease are very low. Hence, advances in front-line therapy of PTCL are long overdue. Pralatrexate, a second-generation antifolate, demonstrated a single agent activity in patients with relapsed and refractory PTCL with a response rate of 27%, including complete remissions in 11% of patients (O'Connor et al. J Clin Onc 2011). We conducted a Phase 1 multi-center dose-escalation study of pralatrexate in combination with standard CHOP (Fol-CHOP) in treatment-naïve PTCL patients. Objectives: The primary objective of the study was to determine the maximum tolerated dose (MTD) of pralatrexate when administered with a standard CHOP regimen to patients with newly diagnosed PTCL. The secondary objectives included safety, tolerability, efficacy and pharmacokinetics of pralatrexate in combination with CHOP (Fol-CHOP). Methods: In Part 1 of this 3+3 dose-escalation study, pralatrexate was administered at 10, 15, 20, 25, or 30 mg/m2 as an IV push on days 1 and 8 of a standard 21-day CHOP regimen (cyclophosphamide 750 mg/m2, doxorubicin 50 mg/m2, vincristine 1.4 mg/m2 [maximum 2 mg] on day 1 and oral prednisone 100 mg on days 1-5). In Part 2 of the study patients were treated at the MTD of pralatrexate established in Part 1, with standard CHOP. In both parts of the study patients were treated with up to 6 cycles of therapy, or until toxicity or disease progression. Patients received antimicrobial prophylaxis, myeloid growth factor support, and "leucovorin rescue" throughout 6 cycles of therapy. Dose-limiting toxicities (DLT) were considered during the 1st cycle of Fol-CHOP and included: Grade 4 infections, treatment-related non-hematological toxicity ≥Grade 3, platelet count < 25 X 109/L at any time, or ANC < 0.5 X 109/L for >7 days despite G-CSF administration. Responses were assessed by the investigator per the Revised Response Criteria for Malignant Lymphoma (Cheson 2007). Results: A total of 31 patients have been enrolled (19 in Part 1; 12 in Part 2). MTD was not reached and pralatrexate dose of 30 mg/m2 in combination with CHOP was selected for Part 2 of the study as predefined by the protocol. The majority of patients were male, White, with the median age of 66 yrs (range, 18-78) at the time of enrolment. PTCL diagnoses included: anaplastic large cell lymphoma, anaplastic lymphomakinase-negative (ALCL, ALK-, n=5), peripheral T-cell lymphoma, not-otherwise specified (PTCL-NOS, n=18), and angioimmunoblastic T-cell lymphoma (AITL, n=5). Fol-CHOP was generally well tolerated with median RDI of 98%. Common (≥ 30%) adverse events (AEs) of any grade were fatigue (n=23), constipation (n=20), nausea (n=16), mucositis (n=14), diarrhea (n=12), anemia (n=9), vomiting (n=10) and oral pain (n=10). Most common (≥ 10%) AEs ≥ grade 3 were anemia (n=6), fatigue (n=4) and neutrophil count decreas (n=5). The only Grade >3 treatment-related AEs (≥10%) was neutrophil count decrease (n=4). SAEs were observed in 13 patients, treatment related SAEs were anemia, febrile neutropenia, dehydration, mucositis and nausea. Five patients withdrew from study: 2 due to disease progression, 1 due to AE and 2 due lapse >28 days between doses. In the 27 patients avaluable for response, the investigator assessed objective response (OR) and complete response (CR) rates were 89% wand 67%, respectively. Conclusions: The combination of pralatrexate and CHOP was well tolerated in treatment-naive PTCL patients. MTD of pralatrexate was not reached, and the protocol-defined maximum dose of 30 mg/m2 on days 1 and 8 of a 21-day CHOP cycle was recomended for future studies. The observed OR and CR rates warrant further evaluation of this regimen in newly diagnosed PTCL patients. Disclosures Shustov: Celgene: Other: Publication assistance; Spectrum Pharmaceuticals: Consultancy, Research Funding. Bhat: Spectrum Pharmaceuticals: Employment. Reddy: Spectrum Pharmaceuticals: Employment.

Recommendations in the form of clinical practice guidelines are increasingly common. Clinical guidelines are systematically developed statements designed to help administrators, practitioners and patients make decisions about appropriate health care for specific circumstances. In North America, guidelines developed by professional societies, government panels and cooperative groups are frequently used to measure quality, to allocate resources and to determine how health care dollars are spent. For clinicians, guidelines provide a summary of the relevant medical literature and offer assistance in deciding which diagnostic tests to order, which treatments to use for specific conditions, when to discharge patients from the hospital, and many other aspects of clinical practice.

Introduction: Entospletinib is an orally bioavailable, selective inhibitor of spleen tyrosine kinase. Targeting the B-cell receptor (BCR) signaling pathway with Bruton's tyrosine kinase (BTK) and PI3Kd inhibitors (BTKi and PI3Kdi), approved for treatment of chronic lymphocytic leukemia (CLL), has been a successful therapeutic strategy. Entospletinib is active in CLL and preclinical data suggest that entospletinib may be effective even in the context of resistance to BTKi, including that conferred by activation of PLCγ2 (Liu et. al. Blood 2015). Methods: This is an ongoing phase 2 trial (NCT01799889) of entospletinib in CLL and non-Hodgkin lymphoma. The study protocol includes 2 CLL cohorts for patients who have been previously treated with BTKi or PI3Kdi and 2 additional cohorts for patients with Richter's transformation who have had analogous prior treatment. Patients were treated with entospletinib monotherapy (400 mg BID) and evaluated using modified Hallek/IWG-CLL criteria every 2 to 3 months as previously described (Sharman et. al. Blood 2014). Results: As of June 28, 2016, 34 patients have been enrolled, and 33 have been treated. Of the 28 patients without Richter's transformation, 23 were previously treated with a BTKi (22 ibrutinib, 1 CC-292) and 5 with a PI3Kdi (idelalisib). Median number of prior treatments was 3 (1-7) for patients with prior BTKi and 5 (3-8) for prior PI3Kdi treatment. In total, 35% of the BTKi patients and 60% of the PI3Kdi patients had either a TP53 mutation or del17p; 75% did not have IgHV hypermutation. A median of 2 months (0-14) had elapsed since the prior treatment; 17 patients had progressive disease on prior therapy, while 11 discontinued prior therapy due to intolerance. Thirteen of the 28 patients enrolled without Richter's transformation remain on study with a median PFS of 5.6 months for the prior BTKi cohort and a median PFS of 6.9 months for the prior PI3Kdi cohort. Of the 15 patients who have stopped therapy, 9 discontinued due to disease progression, 5 discontinued due to an AE, and 1 withdrew consent. Overall, 19 patients were evaluable for response (15 BTKi/4 PI3Kdi; Table 1). Of the 6 patients who achieved a PR, all lacked IgHV hypermutation and 3 had either a TP53 mutation or del17p, and 3 had progressed on prior therapy. Following Richter's transformation, 5 patients have been treated with entospletinib (3 with prior BTKi therapy and 2 with prior PI3Ki). The interval since prior treatment was short ( All patients on study experienced a treatment-emergent AE (TEAE) and 49% experienced a serious AE (SAE; Table 2). Only 1 SAE, pancreatitis, was attributed to entospletinib. The most common TEAEs and laboratory abnormalities are listed in Table 2. Additional Grade ≥3 TEAEs reported in more than 1 patient included sepsis (3), atrial fibrillation (2), dehydration (2), neutropenia (2), pneumonia (2), respiratory failure (2), and urinary tract infection (2). The only TEAE attributable to entospletinib that led to discontinuation of treatment was fatigue. Five patients died on study; 2 from progressive disease and 1 each from heart failure, Guillain-Barre syndrome, and cardiac arrest; 3 of these 5 patients died within 30 days of the last dose of study drug [disease progression (2), cardiac arrest (1)]. Conclusion: Early experience from this trial with ongoing enrollment demonstrates that entospletinib has clinical activity following therapy with either BTKi or PI3Kdi. Continued investigation of treatment with entospletinib following progression after therapy with BCR signaling pathway inhibitors is warranted. Disclosures Sharman: Gilead Sciences, Inc.: Honoraria, Research Funding. Shustov:Celgene: Consultancy, Honoraria; SPECTRUM: Consultancy, Research Funding; Seattle Genetics: Research Funding; Novartis: Research Funding; BMS: Consultancy, Honoraria. Smith:Celgene: Honoraria; Spectrum: Honoraria; Abbvie: Research Funding; Genentech: Honoraria. Kolibaba:Cell Therapeutics: Research Funding; Gilead: Consultancy, Research Funding; Genentech: Research Funding; GSK: Research Funding; Janssen: Research Funding; Acerta: Research Funding; Amgen: Research Funding; Celgene: Research Funding; Novartis: Research Funding; Pharmcyclics: Research Funding; Seattle Genetics: Research Funding; TG Therapeutics: Honoraria, Research Funding. Abella-Dominicis:Gilead Sciences: Employment, Equity Ownership. Zhang:Gilead Sciences: Employment, Equity Ownership. Mitra:Gilead Sciences: Employment, Equity Ownership. Yasenchak:Seattle Genetics: Research Funding. Awan:Pharmacyclics: Consultancy; Innate Pharma: Research Funding; Novartis Oncology: Consultancy.

Background : Increasing data from single-arm studies suggest da-EPOCH-R may be optimal therapy for subsets of aggressive B-NHL, including primary mediastinal B-cell lymphoma, germinal-center DLBCL, and forms with MYC dysregulation. However, da-EPOCH-R administration is considerably more complex than R-CHOP, requiring twice-weekly laboratory monitoring and critical dose adjustments. Major studies in DLBCL (Wilson Blood 2002, Wilson JCO 2008) employ daily GCSF in particular. When daily GCSF is used, a mean overall dose intensity equivalent to dose level 2 is achieved. In younger patients with mediastinal B-cell lymphoma, more than half of patients attained dose level 4. We hypothesized that the use of da-EPOCH in general would have increased over the last decade. In a key subset of patients receiving first-line da-EPOCH-R for aggressive B-NHL, we sought to identify frequency of peg-filgrastim use, as a fundamental deviation from protocol-specified therapy, and identify maximum dose level achieved with peg-GCSF vs. daily GCSF. Given their similarity, we did not anticipate that choice of growth factor would predict likelihood of reaching dose level 4. Methods: We identified all patients receiving da-EPOCH from 2005 to 2015 at the University of Washington and Seattle Cancer Care Alliance and analyzed cases for baseline features, growth factor employed, and maximum dose level attained. Patients with DLBCL and variants (PMBCL, transformed lymphoma, DLBCL-PTLD) and BCL-unclassifiable (BCLU), who received at least 4 cycles of da-EPOCH with rituximab as first-line standard of care therapy (not in context of a clinical trial) were subject to detailed analysis regarding growth factor and dose level achieved. IRB approval was obtained. Results: 165 patients receiving da-EPOCH were initially identified, demonstrating an over 5-fold increase in use of this regimen over the 10-year period (Figure 1). Of these, 73 patients with DLBCL and BCLU met the above criteria, receiving da-EPOCH-R as first-line therapy. Median age was 60 (range 24-78) and patients received a median of 6 cycles (range 4-8; 75% of pts received 6 cycles) of da-EPOCH-R. Most patients (44/73, or 60%) received peg-GCSF rather than daily GCSF with da-EPOCH-R. Overall, the median, highest dose level during first-line therapy was 2 without a difference in groups receiving peg-GCSF or daily GCSF. 61% of patients attained dose level of 2, 41% achieved level 3, and 15% achieved level 4. The proportion of patients who achieved dose level 4 was comparable in the peg-GCSF group (11%) and daily GCSF (21%, p=.24, chi-2). Conclusions: Infusional da-EPOCH is being increasingly used, despite limited single arm data supporting its benefit. For first-line therapy of aggressive B-NHL, da-EPOCH-R is being broadly applied to older subgroups of patients. In that subgroup, peg-GCSF is used more than half of the time. In our population, only 15% achieved a dose level of 4 or higher, compared to over half of patients with PMBCL and a median age of 30 (Dunleavy NEJM 2013). Age is well known as a predictor of da-EPOCH dose intensity (Wilson 2002). Variations from the published protocol due to clinical judgment, as well as patient factors, are also possible factors influencing our dosing findings. Peg-GCSF vs. GCSF did not appear to impact the ability to attain dose level 4, although our study design cannot answer this definitely. Since peg-GCSF is cost effective compared to daily GCSF in lymphoma treated with CHOP (Lyman Curr Med Res Opin 2009) and more convenient, our data suggests that peg-GCSF may be a reasonable strategy to support the da-EPOCH-R regimen. Disclosures Gopal: Seattle Genetics: Research Funding. Shadman:Gilead: Honoraria, Research Funding; Acerta: Research Funding; Pharmacyclics: Honoraria, Research Funding; Emergent: Research Funding.

Background: Peripheral T-cell lymphomas (PTCL) are a heterogeneous group of mature T-cell and natural-killer-cell aggressive non-Hodgkin lymphomas associated with poor prognosis with current therapies. Numerous studies have reported poor survival for PTCL patients with a median Overall Survival (OS) shorter than 2 years and 5-year survival rates of Pralatrexate (Folotyn) is a folate analogue metabolic inhibitor that was the first drug approved in the US for the treatment of patients with relapsed or refractory PTCL (R/R PTCL). Approval was based on results from the pivotal Phase 2 PROPEL study (O'Connor et al, JCO, 2011) of pralatrexate in R/R PTCL, in which pralatrexate monotherapy demonstrated a durable clinical benefit (objective response rate of 29%). Pralatrexate is administered intravenously (IV) at a dose of 30 mg/m2 weekly for 6 weeks of a 7-week treatment cycle. Since pralatrexate and each of the components of the CHOP regimen target different aspects of tumor cell growth and proliferation, there is a potential for synergistic anti-tumor effect, and limited additive toxicities. Objectives: The primary endpoint of the study is the determination of the MTD of pralatrexate in combination with CHOP (Fol-CHOP) in previously untreated PTCL patients. Secondary endpoints included safety, tolerability and ORR (complete response [CR] + partial response [PR]) and pharmacokinetics. Methods: In this study, patients with PTCL received CHOP in combination with pralatrexate, repeated every 3-weeks for up to 6 cycles. Part 1 of the study was to determine the Maximum Tolerated Dose (MTD) of the Fol-CHOP combination. Once the MTD was determined, an additional 10 patients were treated in the Expansion Phase (Part 2). The cohort schema followed a traditional "3+3" design. Pralatrexate was to be administered as 10, 15, 20, 25, or 30 mg/m2 IV push over 3 to 5 minutes on Days 1 and 8 of each cycle. The starting cohort was CHOP + 10 mg/m2 of pralatrexate. Patients received prophylaxis with acyclovir and sulfamethoxazole/trimethoprim during the study and primary prophylaxis with growth factor (filgrastim or pegfilgrastim) support. Dose-limiting toxicities (DLT) were considered during the 1st cycle and included: Severe infections, study treatment-related non-hematological toxicity Grade 3-4, platelet count < 25 X 109/L at any time or ANC < 0.5 X 109/L lasting more than 7 days despite G-CSF administration. Results: A total of 12 patients have been enrolled in Part 1 of the study at the time of abstract submission. Nine patients have completed Cycle 1 and no DLT was reported. Among these nine patients, three patients each were treated at CHOP + 10 mg/m2, 15 mg/m2 and 20 mg/m2 of pralatrexate. One patient (11%) treated with CHOP + 10 mg/m2 had one serious adverse event (SAE) of febrile neutropenia that was deemed unrelated to any study drug. Only four Grade 3 AEs (anemia, constipation, mucosal inflammation, and nausea) were reported, in one patient (11%). The enrollment into the study continues. Conclusions: These interim results demonstrate that the combination of pralatrexate with CHOP (Fol-CHOP) is well tolerated, with all components of CHOP as well as pralatrexate being given at close to or at standard doses. The rates of AEs are comparable to those typically reported with CHOP alone. The study is ongoing to confirm the MTD and to assess preliminary efficacy of the Fol-CHOP combination. Updated results will be presented at the meeting. Disclosures Oki: Novartis: Research Funding. Barta:Celgene, Merck, Seattle Genetics: Research Funding; Janssen: Honoraria, Speakers Bureau. Sharma:Spectrum Pharmaceuticals: Employment. Song:Spectrum Pharmaceuticals: Employment. Mourya:Spectrum Pharmaceuticals: Employment.

Background Peripheral T-cell lymphomas (PTCLs) encompass ~10-15% of aggressive non-Hodgkin lymphomas. Cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP), or variations thereof, are the most commonly used treatment regimens with complete remission (CR) rates ranging from 39-55% (Reimer 2009, d'Amore 2012). With the exception of low international prognostic index (IPI)-anaplastic lymphoma kinase (ALK)-positive ALCL, with 4-year progression-free survival (PFS) and overall survival (OS) ranging from 25-35% and 30-40%, respectively (Ellin 2014). We previously reported the results of this phase 1 trial that evaluated brentuximab vedotin (BV) administered in sequence with CHOP, or in combination with CHP (CHOP without vincristine) in treatment-naive patients (pts) with CD30-expressing PTCL (NCT01309789). The combination therapy (BV+CHP) showed safety and activity at standard doses, with an objective response rate (ORR) of 100% and complete response (CR) rate of 88% (Fanale 2014). The most common adverse events (AEs) experienced by pts were nausea and peripheral sensory neuropathy (69% each). Four-year durability data and updated results on peripheral neuropathy (PN) resolution from the BV+CHP combination treatment arm are presented herein. Methods Adults with CD30-expressing PTCL, including systemic ALCL (anaplastic large cell lymphoma, ALK-negative, or ALK-positive with IPI score ≥2) were eligible for this study. CD30 expression for non-ALCL pts was defined as ≥1% CD30 expression in malignant cells. Pts on the combination treatment arm received 1.8 mg/kg BV and standard-dose CHP q3wk for up to 6 cycles. Pts who achieved at least a partial response (PR) following treatment could receive continued BV 1.8 mg/kg q3wk as single-agent for up to 10 additional cycles. Antitumor response was assessed by the investigator according to the Revised Response Criteria for Malignant Lymphoma (Cheson 2007). Results Twenty-six previously untreated pts received BV+CHP. Disease diagnoses included systemic ALCL (n=19; including ALK-negative, n=16 and ALK-positive, n=3), PTCL-NOS (n=2), angioimmunoblastic T-cell lymphoma (AITL, n=2), adult T-cell leukemia/lymphoma (ATLL, n=2), and enteropathy-associated T-cell lymphoma (EATL, n=1). Twenty-one of the 26 pts who achieved remission with combination treatment continued on to receive single-agent BV. Overall, the 26 pts received a median of 13 cycles (range, 3 to 16) of BV. After a median observation period of 52 months (range 4.6 to 58.3) from first dose, 18 pts remain on study. The estimated 4-year PFS and OS rates are 52% (95% CI: 31, 69) and 80% (95% CI: 59, 91), respectively. The median PFS has not been reached (95% CI: 12.3, -). To date, 15 of 19 ALCL (3/3 ALK-positive, 12/16 ALK-negative), and 6 of 7 non-ALCL pts were alive at last follow-up. Five pts (19%) received subsequent treatment with single-agent BV in long-term follow-up and 3 pts received stem cell transplants (1 autologous, 2 allogeneic) for relapsed disease. There were no pts who underwent a consolidative stem cell transplant. Of the 26 pts treated with combination therapy, 19 (73%) experienced PN. Of these pts, 95% (18 of 19) experienced complete resolution (8 pts), or some resolution or improvement (defined as a decrease by at least 1 grade from worst grade, 10 pts). Of the pts who experienced improvement, 1 pt each improved from Grade 3 to a lowest Grade 2 and from Grade 3 to a lowest Grade 1, and 5 pts improved from Grade 2 to a lowest Grade 1. The median time to resolution of PN symptoms was 5.7 months. Eleven pts had ongoing neuropathy at last follow-up, of which, 9 pts had Grade 1 severity and 2 pts had Grade 2. Conclusions These 4-year durability results demonstrate that among pts with PTCL, initial therapy with BV in combination with CHP can induce long-term remissions with a tolerable safety profile. A phase 3 randomized trial comparing BV+CHP with CHOP for the frontline treatment of CD30-expressing PTCL is ongoing (NCT01777152). Progression-free Survival Figure Figure. Disclosures Horwitz: Celgene: Consultancy, Research Funding; Takeda Pharmaceuticals International Co.: Consultancy, Research Funding; Infinity: Research Funding; Huya: Consultancy; FortySeven: Consultancy; Kyowa Hakka Kirin: Consultancy, Research Funding; Seattle Genetics: Consultancy, Research Funding; Spectrum: Consultancy, Research Funding. Forero-Torres:Seattle Genetics: Research Funding; Genentech/Roche: Research Funding; Juno: Research Funding; Incyte: Research Funding; Abbvie: Research Funding; Novartis: Research Funding; Pfizer: Research Funding. Bartlett:Gilead: Consultancy. Pro:Takeda: Honoraria; Seattle Genetics: Honoraria; Celegene: Honoraria. Chen:Seattle Genetics: Consultancy, Honoraria, Research Funding, Speakers Bureau; Millenium: Consultancy, Research Funding, Speakers Bureau; Genentech: Consultancy, Speakers Bureau; Merck: Consultancy, Research Funding. Davies:Takeda: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Roche: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, accommodation, expenses, Research Funding; Gilead: Consultancy, Honoraria, Research Funding; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel to scientific conferences, Research Funding; GSK: Research Funding; Mundipharma: Honoraria; Janssen: Honoraria; Bayer: Research Funding; Karyopharma: Honoraria, Research Funding; Pfizer: Research Funding. Illidge:Seattle Genetics: Consultancy, Research Funding; Takeda Pharmaceuticals International Co.: Consultancy, Honoraria. Uttarwar:Seattle Genetics: Employment, Equity Ownership. Huebner:Takeda Pharmaceuticals International Co.: Employment, Equity Ownership. Ren:Seattle Genetics: Employment, Equity Ownership.

Introduction: Entospletinib (GS-9973) is an orally bioavailable, selective inhibitor of spleen tyrosine kinase (Syk). Syk is a mediator of B-cell receptor signaling in normal and transformed B-cells. Targeting the B-cell receptor (BCR)-signaling pathway has been the focus in many types of B-cell related hematological malignancies including mantle cell lymphoma (MCL). Methods: This reports the MCL cohort in a phase 2 trial that more broadly evaluated the efficacy and safety of entospletinib (800 mg BID) in patients with relapsed and refractory hematological malignancies (NCT01799889). Tumor response was assessed per Cheson 2007 criteria with imaging planned at weeks 8, 16, 24, and then every 12 weeks. The primary endpoint was PFS at week 16. All efficacy data were assessed by an Independent Review Committee. Results: A cohort of 39 patients with MCL was enrolled. The median age was 72 years (range: 49-92), 64% were male, and a median number of prior regimens were 2 (range: 1-6). Prior therapy included anti-CD20 antibodies (95%), alkylating agents (95%; bendamustine 44%), and anthracyclines (77%). Three patients (8%) have received ibrutinib either as investigational drug (n = 1) or as an approved drug (n = 2), and 1 patient (3%) received idelalisib. Median duration of treatment was 21 weeks (range: 1-87), with 1 patient continuing on treatment. Thirty-five (90%) patients were evaluable for tumor response. Four patients (10%) discontinued prior to initial tumor assessment: death (n = 1), disease progression (n = 2) and investigator's discretion (n = 1). The most common TEAEs (any grade/≥gr 3, independent of causality) and common lab abnormalities are summarized in Table 1. There were 4 TEAEs that led to study drug discontinuation (all n = 1): cardiac arrest, pruritus, pyrexia, and maculopapular rash. Six deaths were reported, none of which were related to study drug. The ORR was 15% (90% CI: 6.9%, 28.1%), with 6 (15%) patients achieving a PR and 23 (59%) patients maintaining a stable disease. The PFS rate at week 16 was 66% (95% CI: 46%, 79%). Median PFS was 5.6 months (95% CI: 3.6 months, 8.9 months). These results are based on data analysis of June 28, 2016. Conclusion: Entospletinib was well tolerated and demonstrated modest activity in patients with relapsed or refractory MCL. Further development of entospletinib in MCL will focus on the development of combination therapy. Figure 1 Waterfall Plot of Best % Change from Baseline in SPD. Figure 1. Waterfall Plot of Best % Change from Baseline in SPD. Figure 2 Kaplan-Meier Curve of Progression-Free Survival. Figure 2. Kaplan-Meier Curve of Progression-Free Survival. Disclosures Sharman: Gilead Sciences, Inc.: Honoraria, Research Funding. Kolibaba:Amgen: Research Funding; Celgene: Research Funding; Cell Therapeutics: Research Funding; Genentech: Research Funding; GSK: Research Funding; Janssen: Research Funding; Acerta: Research Funding; Gilead: Consultancy, Research Funding; Novartis: Research Funding; Pharmcyclics: Research Funding; Seattle Genetics: Research Funding; TG Therapeutics: Honoraria, Research Funding. Shustov:Seattle Genetics: Research Funding; BMS: Consultancy, Honoraria; Celgene: Consultancy, Honoraria; SPECTRUM: Consultancy, Research Funding; Novartis: Research Funding. Nay:Gilead Sciences, Inc.: Honoraria; Janssen: Honoraria, Other: Advisory board; Celgene: Honoraria, Other: Advisory board; Amgen: Other: Advisory board; Lyndbeck: Honoraria; BMS: Honoraria. Zhang:Gilead Sciences: Employment, Equity Ownership. Shi:Gilead Sciences, Inc.: Employment, Equity Ownership. Forero:University of Alabama at Birmingham: Research Funding. Assouline:BMS: Speakers Bureau; Lundbeck: Consultancy; Janssen: Consultancy, Speakers Bureau; Pfizer: Speakers Bureau.

Background Systemic anaplastic large cell lymphoma (ALCL) is a CD30-expressing subtype of peripheral T-cell lymphoma (PTCL). Approximately 40 to 65% of ALCL patients (pts) will develop recurrent disease after frontline treatment, with median overall survival (OS) and progression-free survival (PFS) after relapse of 5.5 and 3.1 months (mos) (Savage 2008, Mak 2013). We have previously reported results of a pivotal phase 2 study of brentuximab vedotin in pts with relapsed or refractory (R/R) systemic ALCL (NCT00866047). Efficacy was demonstrated with an objective response rate (ORR) per investigator of 86% and a complete response (CR) rate of 66%. Peripheral sensory neuropathy was the most common adverse event (AE), experienced in 41% of pts. Herein, we present the end-of-study results with updated data on response durability and peripheral neuropathy (PN) resolution. Methods Fifty-eight pts with R/R systemic ALCL, ALK-positive or ALK-negative, received 1.8 mg/kg brentuximab vedotin every 3 weeks as a 30-minute outpatient IV infusion for up to 16 cycles. The primary endpoint was the ORR per independent review according to the Revised Response Criteria for Malignant Lymphoma (Cheson 2007). Long-term follow-up to evaluate disease status was assessed per the investigator every 3 mos for 2 years, every 6 mos through Year 5, and annually thereafter. CT scans were required if progression was suspected clinically. Pts who experienced PN were followed for symptom improvement/resolution until approximately 3 years into long-term follow-up. Results The estimated 5-year OS and PFS for all enrolled patients was 60% (95% CI: 47%, 73%) and 39% (95% CI: 25%, 52%), respectively. At study closure, which occurred 5 years after the last patient's end-of-treatment (EOT) visit, the median OS was not reached (95% CI: 21.3, -), and the median PFS was 20 mos (95% CI: 9.4, -). Pts were observed for a median of 71.4 mos (range, 0.8 to 82.4) from first dose. Of the pts who achieved a CR per investigator (38 of 58, 66%), the median OS (endpoints of 95% CI not estimable) and PFS (95% CI: 21.3, -) were not reached. Median OS for pts who achieved partial response per investigator (PR, 12 of 58, 21%) was 11.6 mos (95% CI: 3.1, -). Median duration of objective response was 25.6 mos (95% CI: 11.8, - [range, 0.9 to 79.7+]) and was not reached for CR pts (95% CI: 20.0, - [range, 0.9 to 79.7+]). Of the 58 enrolled pts, 42 (72%) had ALK-negative disease. Median PFS for ALK-negative and ALK-positive ALCL was 20 mos (95% CI: 6.7, -) and 25.5 mos (95% CI: 8.0, -) respectively, with the median OS not reached for each. The estimated 5-year OS was 61% (95% CI: 47%, 76%) for ALK-negative and 56% (95% CI: 32%, 81%) for ALK-positive pts. Of the 38 CR pts, 16 received a consolidative stem cell transplant (SCT, 8 allogeneic, 8 autologous). Median PFS was not reached in these pts who underwent transplant. Median PFS for the CR pts that did not undergo transplant was 39.4 mos (95% CI: 14.3, -). Sixteen pts, with a median observation time of 75.4 mos (range 69 to 82.4), remained in remission at the end of the study without the start of new therapy other than consolidative SCT. Among these pts, 8 received a consolidative SCT, and the remaining 8 pts (14% of all enrolled pts) remained on study and in remission without any additional therapy after single-agent brentuximab vedotin. Thirty-three pts (57% of enrolled pts) experienced PN. Thirty pts (30 of 33, 91%) experienced resolution or improvement, of whom, 22 (67%) reported complete resolution, and 8 (24%) reported some resolution or improvement at last assessment. Of the 11 pts with ongoing neuropathy at last follow-up, 8 pts had Grade 1 severity and 3 pts had Grade 2. Conclusions These end-of-study results demonstrate that among pts with R/R systemic ALCL, the majority of pts have achieved clinically significant durable remissions, and a subset may have been cured with single-agent brentuximab vedotin. Furthermore, associated toxicities are manageable, with high rates of resolution for PN, the most common toxicity associated with brentuximab vedotin. A randomized phase 3 trial is ongoing to evaluate the combination of brentuximab vedotin with cyclophosphamide, doxorubicin, and prednisone for frontline treatment of CD30-expressing peripheral T-cell lymphomas, including systemic ALCL (NCT01777152). Overall Survival and Progression-Free Survival Figure. Figure. Disclosures Pro: Takeda: Honoraria; Seattle Genetics: Honoraria; Celegene: Honoraria. Brice:Gilead: Honoraria; Takeda Pharmaceuticals International Co.: Honoraria, Research Funding; Seattle Genetics: Research Funding; Bristol Myers-Squibb: Honoraria; Roche: Honoraria. Bartlett:Gilead: Consultancy. Rosenblatt:University of Miami: Employment; Seattle Genetics: Research Funding. Illidge:Takeda Pharmaceuticals International Co.: Consultancy, Honoraria; Seattle Genetics: Consultancy, Research Funding. Matous:Seattle Genetics: Research Funding, Speakers Bureau; Celgene: Consultancy, Speakers Bureau; Takeda Pharmaceuticals International Co.: Speakers Bureau. Connors:Bristol Myers Squib: Research Funding; F Hoffmann-La Roche: Research Funding; Millennium Takeda: Research Funding; Seattle Genetics: Research Funding; NanoString Technologies: Research Funding. Fenton:Seattle Genetics: Employment, Equity Ownership. Huebner:Takeda Pharmaceuticals International Co.: Employment, Equity Ownership. Pinelli:Seattle Genetics, Inc.: Employment, Equity Ownership. Shustov:Seattle Genetics: Research Funding; Celgene: Consultancy, Honoraria; Novartis: Research Funding; SPECTRUM: Consultancy, Research Funding; BMS: Consultancy, Honoraria.

Introduction: Outcomes for patients with aggressive T cell lymphomas who are not cured by frontline therapies are poor. A Canadian retrospective analysis showed median overall survival (OS) to be 6.5 months combined for peripheral T-cell lymphoma (PTCL) patients in first relapse (Rel) and patients with primary refractory (Ref) disease (Mak, et al. JCO 2013). There have been no prospective studies that have examined the differences between Rel and Ref patients. In this analysis, we examined clinical features and outcomes for 285 patients prospectively enrolled in the COMPLETE Registry who completed frontline therapy and identified 119 patients with either Rel or Ref disease. We describe differences in clinical features, treatment, and outcomes between Rel and Ref patients. Methods: Patients with all subtypes of PTCL from 72 sites in the US were prospectively enrolled in the COMPLETE registry at initial diagnosis. Clinical and histopathologic features, treatment regimens, goals of therapy, toxicities, and outcomes were recorded. For this analysis, Ref disease was defined as no response to initial treatment or progression during or within 1 month of completing frontline therapy. Rel disease was defined as progression at least 1 month from completion of frontline therapy in patients who achieved a complete response (CR) or partial response (PR). Results: Of 285 patients in COMPLETE who had locked treatment and follow-up records required for this analysis, 50 met the criteria for Rel and 69 for Ref PTCL. Demographics (age, gender, race) and key clinical characteristics at initial diagnosis (histology [Table 1], bone marrow involvement, LDH, ECOG performance status) did not significantly differ between Rel and Ref patients. According to the treating physician, the primary goal of second-line therapy was cure in over half of both groups (52% for Rel, 60% for Ref); the remainder were managed with palliative intent. Rel patients received novel therapies (see Table 2 for definition) more frequently than Ref patients (58% vs. 28%) (P = 0.005) and were less likely to receive multi-agent regimens (24% vs. 45%; P = 0.04) [Table 2]. In the 55 Rel and Ref patients who received single-agent therapy, the most common agents were brentuximab vedotin (20%), romidepsin (15%), pralatrexate (9%) and gemcitabine (7%). In the 30 patients who received multi-agent therapy, the most common regimens were ICE (ifosfamide, carboplatin and etoposide) (17%), GemOx (gemcitabine and oxaliplatin) (17%), and CHOP or CHOP-like plus etoposide (13%). Despite similar frontline therapy with combination chemotherapy regimens, more Rel patients underwent high dose therapy and transplant compared to the Ref group (30% vs. 4%; P = 0.0005). Although single agent versus combination therapy showed similar objective response rates (ORR= CR+PR), the ORR of novel vs. traditional chemotherapy showed a trend favoring novel agents for the entire cohort (57% vs. 38%; P = 0.07). The ORR to second-line therapy was higher in Rel patients (63% vs. 38%; P = 0.02) as was the proportion achieving a CR (38% vs. 15%; P = 0.02). Further, Rel patients had longer OS compared Ref patients, with a median OS of 31 months (95% CI: 22.1 months to not reached) versus 10.2 months (95% CI: 6.5 - 15.9 months) from first diagnosis (Figure 1a) and 14.6 months versus 6.1 months (P = 0.048) from the time of relapse or progression (Figure 1b). For both Rel and Ref patients, there was no difference in survival by PTCL subtype. In both the Rel group and Ref groups, survival was significantly longer in patients treated with curative vs. palliative (as determined by the treating physician) intent (P = 0.01). Conclusions: Our analysis of real world outcomes in patients with aggressive T cell lymphomas demonstrates that outcomes are significantly worse for patients with Ref compared to those with Rel disease. Interestingly, novel single agent therapies were used most often as second-line therapy in Rel patients while multi-agent chemotherapy was used more frequently in Ref patients, despite the demonstration of activity of novel single agents in the Ref setting in other studies. The high proportion of patients with Rel or Ref disease in COMPLETE, and the demonstrated activity of novel agents in the Rel and Ref settings, supports initiatives to incorporate novel agents into frontline therapy for PTCL. Download : Download high-res image (122KB) Download : Download full-size image Download : Download high-res image (156KB) Download : Download full-size image Download : Download high-res image (109KB) Download : Download full-size image Disclosures Lansigan: Spectrum: Consultancy, Research Funding; Pharmacyclics: Consultancy; Teva: Research Funding; Celgene: Consultancy. Horwitz: Huya: Consultancy; Celgene: Consultancy; Takeda: Consultancy, Research Funding; Infinity: Consultancy, Research Funding; Bristol-Myers Squibb: Consultancy; Kyowa Hakka Kirin: Consultancy, Research Funding; Spectrum: Consultancy, Research Funding; Seattle Genetics: Consultancy, Research Funding; ADCT Therapeutics: Research Funding. Pinter-Brown: Celgene: Consultancy; Spectrum Pharmaceuticals: Consultancy; Seattle Genetics: Consultancy. Carson: American Cancer Society: Research Funding. Pro: Seattle Genetics: Honoraria; Takeda: Honoraria; Celegene: Honoraria. Hsi: Onyx Pharmaceuticals: Honoraria; Seattle Genetics: Honoraria; Eli Lilly: Research Funding; Cellerant: Honoraria, Research Funding; Abbvie: Honoraria, Research Funding; HTG Molecular Diagnostics: Consultancy. Federico: MedNet Solutions: Consultancy. Gisselbrecht: Roche/Genentech: Research Funding, Speakers Bureau. Schwartz: MedNet Solutions: Employment. Bellm: Merck: Equity Ownership; Johnson & Johnson: Equity Ownership; BMS: Equity Ownership; MedNet Solutions: Consultancy, Other: Reimbursement of travel-related expenses. Acosta: Spectrum Pharmaceuticals: Employment, Equity Ownership. Foss: Celgene: Consultancy, Research Funding, Speakers Bureau; Seattle Genetics: Consultancy, Speakers Bureau; Spectrum Pharmaceuticals: Consultancy; Eisai: Consultancy.

Background:PD-1 and PD-L1/PD-L2 are expressed by malignant T-cells in mycosis fungoides (MF) and Sézary syndrome (SS). PD-1 is additionally expressed by tumor-infiltrating cytotoxic T-cells and PD-L1 is expressed by macrophages and other stromal components of the tumor microenvironment in these diseases. Moreover, reports of 9p24.1/PD-L2 translocation and CTLA4-CD28 fusion events in MF/SS support a genomic basis for immune evasion. Here, we explore the clinical activity of pembrolizumab, an immune checkpoint inhibitor of the PD-1/PD-L1 axis, in MF/SS. Methods:Patients (pts) with MF/SS stages IB-IV treated with at least 1 prior systemic therapy were enrolled in this phase 2, single-arm study coordinated by the Cancer Immunotherapy Trials Network (CITN). A Simon two-stage design was applied where stage 2 is initiated if 1 of 9 pts had an objective response. An additional 15 pts were planned in stage 2. Pembrolizumab was administered at 2 mg/kg every 3 weeks and treatment was allowed up to 2 years. The primary endpoint was overall response rate (ORR) as determined by the consensus global response criteria. Secondary endpoints were safety/tolerability, time to response (TTR), duration of response (DOR) and progression-free survival (PFS). Correlative biomarker studies included immunohistochemistry (IHC) staining for PD-L1, PD-L2, and multiple immune subsets as well as serum analysis of 62 cytokines and chemokines. Phenotypic and functional profiling of malignant and non-malignant immune cells will be performed by flow cytometry and mass cytometry (CyTOF). Results: The study completed enrollment and all 24 patients received at least one dose of pembrolizumab. Median age was 67 (range 44-85); 18 were male. Patients were advanced stage with 23 patients (96%) stage IIB or higher, including 15 patients (63%) with stage IVA SS. Most pts were heavily treated with a median of 4 prior systemic therapies (range 1-11). The median follow-up time was 40 weeks (range 9-60 weeks). The objective response rate (ORR) was 38% with 1 complete response (CR) and 8 partial responses (PR). Of the responding pts, 6 pts had 90% or greater improvement in skin disease as measured by mSWAT. An additional 9 pts (38%) had stable disease (SD). The median TTR was 11 weeks (range 8-41 weeks). Responses were durable with 8 of 9 (89%) responses currently ongoing at a median of 32 weeks of duration (4-46). The median PFS has not yet been reached, and the one-year PFS was 69%. There was no significant association between response and clinical characteristics including stage, disease type (MF vs. SS), and number of prior therapies, nor with skin tissue expression of PD-1, PD-L1, PD-L2, or infiltrating CD8+ T-cells as determined by IHC. Planned additional correlatives including CyTOF profiling, gene expression profiling, T cell receptor high throughput sequencing, multiplexed ion beam imaging (MIBI), and whole exome sequencing will explore potential predictive biomarkers of response. Adverse events (AE) were consistent with those seen in prior studies of pembrolizumab with the exception of an immune-mediated skin flare reaction seen in 6 pts (2 grade 2 and 4 grade 3). Skin flares occurred exclusively in patients with SS (6/15; 40%) and were associated with lower serum levels of the cytokines IL-7 and SCF prior to pembrolizumab treatment (p=0.01 and p=0.02 respectively, n.s. by Bonferroni correction). Pts with the skin flare reaction experienced increases in serum IFN-gamma, IL-12p40, IL-15, LIF, G-CSF, and CCL4 following treatment. There were two treatment related serious adverse events (SAE), both immune related. One pt experienced grade 2 pneumonitis which resolved with systemic corticosteroids. Another patient experienced grade 3 diarrhea secondary to steroid-refractory duodenitis. Conclusions: Pembrolizumab has significant clinical activity in pts with previously treated MF/SS. Responses were durable and were not associated with any identifiable clinical or pathologic characteristics. Treatment was well tolerated with a toxicity profile consistent with prior pembrolizumab studies, though 40% of pts with SS developed a notable skin flare reaction. These findings support further study of PD-1 blockade in the treatment of MF and SS. A phase 2 trial of pembrolizumab in combination with interferon-gamma is being developed based on these results. Disclosures Porcu: Millenium: Other: investigator in a clinical trial; miRagen: Other: Investigator in a clinical trial; celgene: Other: Investigator in a clinical trial; Innate Pharma: Other: Investigator in a clinical trial. Foss:Celgene: Consultancy, Research Funding, Speakers Bureau; Eisai: Consultancy; Seattle Genetics: Consultancy, Speakers Bureau; Spectrum Pharmaceuticals: Consultancy. Moskowitz:Bristol Myers Squibb: Honoraria; Merck: Honoraria; Seattle Genetics: Honoraria, Research Funding. Sokol:Seattle Genetics: Consultancy; Spectrum: Consultancy. Yearley:Merck: Employment. Chartash:Merck: Employment. Townson:Merck: Employment. Horwitz:Spectrum: Consultancy, Research Funding; Bristol-Myers Squibb: Consultancy; Huya: Consultancy; Infinity: Consultancy, Research Funding; Kyowa Hakka Kirin: Consultancy, Research Funding; Takeda: Consultancy, Research Funding; Seattle Genetics: Consultancy, Research Funding; Celgene: Consultancy; ADCT Therapeutics: Research Funding. Kim:Seattle Genetics: Consultancy, Other: Investigator in a clinical trial; Merck: Other: Investigator in a clinical trial; Neumedicine: Consultancy; Soligenix: Consultancy; Galderma: Consultancy; Genentech: Other: Investigator in a clinical trial; Innate Pharma: Other: Investigator in a clinical trial; Kyowa Hakko Kirin: Consultancy, Honoraria, Other, Research Funding; Millenium: Consultancy, Other: Investigator in a clinical trial; Eisai: Consultancy, Other: Investigator in a clinical trial; Actelion: Consultancy, Other: Investigator in a clinical trial; Celgene: Consultancy; MiRagen: Consultancy; Horizon: Consultancy.

A 58-year-old woman presents with a recent diagnosis of peripheral T-cell lymphoma, unspecified. She has read through Google® that the “best treatment” for this disorder is stem cell transplantation—she asks you if you recommend this treatment?

BACKGROUND: Peripheral T-cell lymphomas (PTCL) encompass a heterogeneous group of neoplasms accounting for 10 to 15% of non-Hodgkin lymphomas worldwide. Prognosis for PTCL patients is poor and consolidation in first remission with autologous stem cell transplantation (ASCT) is widely used. Most patients though still relapse after transplant. We hypothesized that pre-ASCT bone marrow (BM) involvement detected by multi-parameter flow cytometry (FC) would identify patients with inferior outcome after ASCT. METHODS: We retrospectively analyzed the outcome of 29 consecutive PTCL patients who underwent ASCT at the Fred Hutchinson Cancer Research Center from April 2004 through July 2014. Pre-ASCT BM involvement by flow cytometry (FC) was defined as the presence of an abnormal T-cell population detected by multi-parameter FC analysis in a BM aspirate obtained within 30 days prior to ASCT. An abnormal T-cell population accounting for a percentage equal or greater than 0.01% of total leukocytes after red blood cell lysis was considered significant. RESULTS: Ten patients (34%) with angioimmunoblastic T cell lymphoma (AITCL), 8 (27%) with ALK-negative anaplastic large cell lymphoma (ALCL), 8 (27%) with peripheral T cell lymphoma, not otherwise specified (PTCL-NOS) and 3 (12%) with other PTCL sub-types were included. Median age at transplant was 54 (range: 29-71). Twenty patients (76%) presented at ASCT in complete remission (CR) per 1999 Cheson criteria and 9 (31%) were in first CR (CR1). Fifteen patients (50%) underwent ASCT upfront. Pre-ASCT BM involvement was detected by FC analysis in 7 patients (24%, 3 patients with AITCL, 1 patient with ALCL and 3 patients with PTCL-NOS) and by morphology in 2 patients (7%, 2 patients with AITCL). The 7 patients with pre-ASCT BM involvement detected by FC experienced a significantly higher 4-year cumulative incidence of relapse (CIR) (85% versus 36%, p < 0.001) and lower overall survival (OS) (19% versus 89%, p < 0.001) with a median follow-up of 51 months. These findings were confirmed in multivariable analysis for CIR (HR = 7.37, CI = 1.14 - 47.61, p = 0.03) and OS (HR = 7.04, CI = 1.29 - 38, p = 0.024). The IPI score, absence or presence of CR1 and the number of prior therapies were included in a multivariable model for CIR, while age and the IPI score at diagnosis were taken into account for OS. ASCT performed in CR1 was associated with lower CIR (HR = 0.11, CI = 0.03-0.041, p < 0.001). Histologic subtypes did not impact CIR (p = 0.97) nor OS (p = 0.91) and they did not significantly differ between the groups with and without pre-ASCT BM involvement detected by FC (p = 0.60) after applying Fisher's exact test. Further analysis of the 22 patients presenting in CR at ASCT revealed that in this subgroup, pre-ASCT BM involvement by FC (n = 4) was also associated with higher CIR (75% versus 32%, p = 0.002) and lower OS (25 versus 94%, p CONCLUSION: Pre-ASCT BM involvement by FC correlated with dramatically higher relapse rates and an inferior OS in PTCL patients after ASCT. Furthermore, we demonstrate that residual disease, detected only in patients meeting Cheson 1999 criteria for CR at ASCT is capable of predicting a higher risk for relapse. These findings should encourage further evaluation of minimal residual disease in PTCL patients achieving complete remission as defined per Cheson 1999 and 2007 criteria. Figure 1. Cumulative incidence of relapse Figure 1. Cumulative incidence of relapse Figure 2. Overall survival Figure 2. Overall survival Disclosures Gopal: Merck: Research Funding; Emergent/Abbott: Research Funding; Cephalon/Teva: Research Funding; BioMarin: Research Funding; Sanofi-Aventis: Honoraria; Millenium: Honoraria, Research Funding; Seattle Genetics: Consultancy, Honoraria, Research Funding; Janssen: Consultancy, Research Funding; Pfizer: Consultancy, Research Funding; Spectrum: Consultancy, Research Funding; Gilead: Consultancy, Research Funding; Piramal: Research Funding; Biogen Idec, BMS: Research Funding. Maloney:Juno Therapeutics: Research Funding; Roche/Genentech: Honoraria; Janssen Scientific Affairs: Honoraria; Seattle Genetics: Honoraria. Till:Roche-Genentech: Research Funding.

Background PTCL is an aggressive subgroup of NHL. Outcomes in R/R PTCL remain poor and alternative therapies are needed. Alisertib is an investigational, oral, selective inhibitor of Aurora A kinase, a key mitotic regulator that is overexpressed/amplified in various cancers, including lymphomas. Phase 2 data with single-agent alisertib in R/R NHL (Friedberg et al JCO 2014) and R/R PTCL (Barr et al JCO 2015) suggested promising antitumor activity. This international phase 3 trial evaluated single-agent alisertib vs investigator's choice in pts with R/R PTCL, and was the first initiated randomized trial in this setting. Methods Adult pts with R/R PTCL (WHO criteria) after ≥1 prior conventional systemic cytotoxic therapy, who had measurable disease by 2007 IWG criteria, tumor biopsy for central hematopathology review, and ECOG PS 0-2, were eligible. Pts were randomized 1:1 (stratified by nodal vs extranodal disease, IPI score [0/1/2 vs 3/4/5], and region [North America + EU vs Rest of World]) to receive alisertib 50 mg twice daily as an enteric coated tablet on d 1-7 in 21-d cycles (alisertib arm), or investigator's choice of: pralatrexate 30 mg/m2 IV once weekly for 6 weeks in 7-week cycles; romidepsin 14 mg/m2 IV on d 1, 8, and 15 in 28-d cycles; or gemcitabine 1000 mg/m2 IV on d 1, 8, and 15 in 28-d cycles (comparator arm), until disease progression, unacceptable toxicity, or 2 yrs (extendable if benefit shown). Selected comparator drug could not have been previously received by the pt, and crossover to another study drug was not permitted. The primary endpoints were ORR (CR+PR) and PFS by IWG criteria per central (IRC) assessment. Secondary endpoints included OS, CR rate, DOR, and safety. The study employed an adaptive sample size reassessment approach, with two interim analyses (IA1, futility analysis; IA2) plus a planned final analysis. Sample size was determined to give 80% power to detect a difference in ORR (assumed 55% alisertib vs 30% comparator) at IA2, and ~85% power to detect a reduction in HR for PFS in favor of alisertib at the final analysis with a maximum of 354 randomized pts and a maximum of 261 PFS events. Conditional power calculation based on PFS at IA2 could determine whether the study would be stopped for futility or if sample size would be expanded for the final analysis. Here we report data from IA2 (17Sep2014 data cut-off). Results 238 pts were randomized across 27 countries (120 alisertib, 118 comparator). Baseline characteristics were balanced between arms (alisertib vs comparator): median age 63 vs 64 yrs; male 68% vs 64%; Ann Arbor stage III/IV 74% vs 72%; bone marrow involvement at study entry 29% vs 35%. Efficacy data are shown in the Table. ORR by IRC with alisertib vs comparator was 33% vs 43% (OR 0.65 [95% CI: 0.34-1.23]), including 16% vs 25% CR. Median duration of follow-up was 9.5 vs 9.2 mos with alisertib vs comparator. Median PFS by IRC was 3.7 vs 3.4 mos (HR 0.939 [95% CI: 0.681-1.293]; Figure) and median OS was 9.9 vs 12.2 mos (HR 0.901 [95% CI: 0.607-1.337]; OS data not mature at current follow-up). Median treatment duration with alisertib vs comparator was 12 vs 10 weeks and 15% vs 5% of pts remained on treatment at data cut-off. With alisertib vs comparator, rates of Gr ≥3 AEs were 85% vs 81%, serious AEs 53% vs 55%, discontinuations due to AEs 9% vs 13%, and on-study treatment-related deaths 2% vs 2%. Gr ≥3 AEs (>20% all pts) were neutropenia 44% vs 27%, thrombocytopenia 29% vs 27%, and anemia 30% vs 11%. Conclusion While alisertib showed activity in R/R PTCL, there was no significant efficacy benefit vs comparator. Based on IA2, there was a low probability of claiming superiority of alisertib for PFS at the final analysis; therefore, per IDMC recommendation enrollment was stopped at 271 pts and pts deriving benefit continue on treatment. The study was unblinded and final data are pending. Table. Efficacy Alisertib Comparator All Pralatrexate Romidepsin Gemcitabine Response, n (%)*† n=83 n=80 n=40 n=17 n=23 ORR (CR+PR) 27 ( 33) 34 (43) 16 (40) 10 (59) 8 (35) CR 13 (16) 20 (25) 10 (25) 5 (29) 5 (22) PR 14 (17) 14 (18) 6 (15) 5 (29) 3 (13) SD 26 (31) 18 (23) 13 (33) 2 (12) 3 (13) PD 30 (36) 27 (34) 11 (28) 4 (24) 12 (52) Median DOR*† (responders), mos 5.0 5.8 - - - PFS*‡ n=120 n=118 n=67 n=21 n=30 Events, n (%) 78 (65) 73 (62) 45 (67) 7 (33) 21 (70) Median, mos 3.7 3.4 3.4 8.0 1.9 *IRC assessment †Response-evaluable pts (n=163); n=75 not evaluable (not dosed/ no post-baseline IRC assessment/ no central confirmation of PTCL) ‡ITT analysis (n=238) Disclosures O'Connor: Spectrum: Research Funding; Seattle Genetics: Research Funding; Takeda Pharmaceutical Company Limited: Research Funding. Off Label Use: Investigational Aurora A kinase inhibitor, alisertib, for patients with relapsed/refractory peripheral T-cell lymphoma.. Demeter:Amgen: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees; Roche: Membership on an entity's Board of Directors or advisory committees; BMS: Membership on an entity's Board of Directors or advisory committees. Masszi:BMS: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees; Janssen-Cilag: Membership on an entity's Board of Directors or advisory committees; Takeda: Membership on an entity's Board of Directors or advisory committees. Ramchandren:Kite Pharma: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Seattle Genetics: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Pharmacyclics: Research Funding. d'Amore:Takeda Pharmaceutical Company Limited: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau. Foss:Celgene: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Millennium Pharmaceuticals, Inc., a wholly owned subsidiary of Takeda Pharmaceutical Company Limited: Membership on an entity's Board of Directors or advisory committees; Spectrum: Membership on an entity's Board of Directors or advisory committees; Seattle Genetics: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Kim:Merck: Research Funding; Takeda: Research Funding; Novartis: Research Funding; Kyowa-Kirin: Research Funding; Donga: Research Funding; Roche: Research Funding. Zinzani:J&J: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Pfizer: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Gilead: 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; Takeda: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Liu:Millennium Pharmaceuticals Inc., a wholly owned subsidiary of Takeda Pharmaceutical Company Limited: Employment. Jung:Millennium Pharmaceuticals Inc., a wholly owned subsidiary of Takeda Pharmaceutical Company Limited: Employment. Zhou:Millennium Pharmaceuticals Inc., a wholly owned subsidiary of Takeda Pharmaceutical Company Limited: Employment. Leonard:Millennium Pharmaceuticals Inc., a wholly owned subsidiary of Takeda Pharmaceutical Company Limited: Employment. Dansky Ullmann:Millennium Pharmaceuticals Inc., a wholly owned subsidiary of Takeda Pharmaceutical Company Limited: Employment. Shustov:Seattle Genetics: Research Funding.

Background: Peripheral T-cell lymphomas (PTCL) encompass a subset of aggressive non-Hodgkin lymphomas. Many PTCL tumor cells express the surface marker CD30, including systemic anaplastic large cell lymphoma (ALCL) where CD30 is uniformly expressed. Multi-agent chemotherapy regimens provide inadequate long-term outcomes: complete remission (CR) rates range from 39-53% and 5-year overall survival (OS) rates are 12-49%, depending on subtype. Three-year progression-free survival (PFS) and OS rates are approximately 30% and Methods: The analysis set consisted of patients who received the combination treatment (tx) regimen (BV+CHP; 6 cycles, q3wk, IV). Patients who achieved at least a partial remission (PR) following BV + CHP could subsequently receive up to 10 additional cycles of single-agent BV (1.8 mg/kg q3wk). ALK+ systemic ALCL pts must have had an International Prognostic Index (IPI) score ≥2. Antitumor response assessments were per investigator according to the Revised Response Criteria for Malignant Lymphoma (Cheson 2007). Efficacy endpoints included PFS and OS, which were estimated using Kaplan-Meier methodology. Results: Twenty-six pts received BV + CHP combination treatment. Diagnoses included systemic ALCL (n=19; 3ALK+, 16 ALK-), peripheral T-cell lymphoma-NOS (n=2), angioimmunoblastic T-cell lymphoma (n=2), adult T-cell leukemia/lymphoma (n=2), and enteropathy-associated T-cell lymphoma (n=1). The objective response rate to tx was 100% and CR rate was 88%. Treatment-emergent adverse events (TEAEs) with a severity of at least Grade 3 (≥10% incidence) were febrile neutropenia, neutropenia, anemia and pulmonary embolism with 73% reporting any grade peripheral neuropathy. At the time of this analysis, 20 pts remained on study for long term follow-up (LTFU). The median observation time from first dose was 38.7 months (range, 4.6 to 44.3). The 3-year OS rate was 80% (95% CI: 59, 91 months) and the median PFS was not reached (95% CI: 12.3, -). Twenty one pts received a median of 10 doses (range, 1 to 10) of BV post BV-CHP. Nine/19 (47%) ALCL and 5/7 (71%) non-ALCL pts have not experienced disease progression or death. A Standardized Medical Dictionary for Regulatory Activities (MedDRA) Query (SMQ) was performed for peripheral neuropathy (PN). Eighteen of 19 (95%) patients who received combination therapy experienced either complete resolution (n=7, 37%) or improvement by at least 1 grade level (n=11, 58%) in neuropathy symptoms. There were a total of 44 PN events of which 23 (52%) resolved and 14 (32%) improved. Five pts (19%) who experienced disease progression after completing treatment received subsequent treatment with BV in LTFU, and 3 patients received stem cell transplants (1 autologous, 2 allogenic). There were no patients who received a consolidative stem cell transplant in first remission. Conclusions: Durable remissions were observed with BV in combination with CHP in newly diagnosed pts with PTCL. After over 3 years of follow-up, clinical outcomes compare favorably with historical data in PTCL pts. An ongoing randomized trial with 450 pts is comparing BV+CHP with CHOP for the frontline treatment of CD30+ PTCL (ClinicalTrials.gov NCT01777152). Final resultsfrom this trial are expected in 2017 to 2018. Progression-Free Survival: Brentuximab Vedotin in Combination with CHP Figure 1. Figure 1. Disclosures Off Label Use: Brentuximab vedotin (BV) is indicated in the US for treatment of patients with Hodgkin lymphoma after failure of autologous stem cell transplant or after failure of at least two prior multi-agent chemotherapy regimens in patients who are not ASCT candidates and for the treatment of patients with systemic anaplastic large cell lymphoma after failure of at least one prior multi-agent chemotherapy regimen. This study evaluates the use of brentuximab vedotin as a frontline treatment in patients with systemic ALCL or CD30-positive mature T-cell and NK-cell neoplasms in combination with multiagent chemotherapy.. Shustov:Seattle Genetics: Research Funding. Forero-Torres:Seattle Genetics: Research Funding. Bartlett:Seattle Genetics: Consultancy, Research Funding; Gilead: Consultancy, Research Funding; Janssen: Research Funding; Pharmacyclics: Research Funding; Genentech: Research Funding; Pfizer: Research Funding; Novartis: Research Funding; Millennium: Research Funding; Colgene: Research Funding; Medimmune: Research Funding; Kite: Research Funding; Insight: Research Funding; MERC: Research Funding; Dynavax: Research Funding; Idera: Research Funding; Portola: Research Funding; Bristol Meyers Squibb: Research Funding; Infinity: Research Funding; LAM Theapeutics: Research Funding. Advani:Genetech: Consultancy; Seattle Genetics, Inc.: Research Funding. Pro:Seattle Genetics: Consultancy, Other: Travel expenses, Research Funding; Takeda: Honoraria, Other: Travel expenses. Chen:Genentech: Consultancy, Speakers Bureau; Seattle Genetics, Inc.: Consultancy, Other: Travel expenses, Research Funding, Speakers Bureau; Millennium: Consultancy, Research Funding, Speakers Bureau. Davies:Takeda: Honoraria; Seattle Genetics: Research Funding. Illidge:Seattle Genetics: Consultancy, Research Funding; Takeda: Consultancy, Honoraria. Huebner:Takeda Pharmaceuticals International Co.: Employment, Equity Ownership. Kennedy:Seattle Genetics,Inc: Employment, Equity Ownership, Honoraria, Speakers Bureau. Fanale:Merck: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; BMS: Research Funding; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Takeda: Honoraria, Research Funding; Infinity: Membership on an entity's Board of Directors or advisory committees; Spectrum: Membership on an entity's Board of Directors or advisory committees; Seattle Genetics: Honoraria, Research Funding; Genentech: Research Funding; Medimmune: Research Funding; Novartis: Research Funding; Bayer: Membership on an entity's Board of Directors or advisory committees; Amgen: Membership on an entity's Board of Directors or advisory committees; Molecular Templates: Research Funding; ADC Therapeutics: Research Funding; Onyx: Research Funding; Gilead: Research Funding.

Background: MRD is an established prognostic/predictive factor in ALL. Achieving MRD negativity (MRDNeg) early during treatment is associated with superior outcomes with pediatric regimens. However, little is known about how to use MRD assessments with hyperCVAD (hyperfractionated cyclophosphamide, vincristine, doxorubicin, and dexamethasone, alternating with methotrexate and cytarabine), one of the most commonly used regimens in adults with ALL. MRDNeg at 3 months has been shown to be predictive of outcome with hyperCVAD + tyrosine kinase inhibitor (TKI) in Philadelphia chromosome (Ph)+ ALL (Ravandi, Blood, 2013, p. 1214), but this is relatively late in the treatment course. We hypothesized that achieving MRDNeg earlyduring treatment would be associated withbetter outcomes with hyperCVAD. Methods: We performed a retrospective analysis of our center's experience since 2005 under an IRB-approved protocol. We included pts with ALL (excluding Burkitt and mixed-phenotype) age >18 years (yrs) who received hyperCVAD as initial therapy. MRD was assessed primarily by either multiparameter flow cytometry or BCR-ABL quantitative PCR on bone marrow, though other techniques (e.g., cytogenetics [CG]) were considered if obtained. Timing and nature of assessments were left to treating physicians. Pts were not defined as MRDNeg until all assays performed were unable to detect any disease. Clinical risk at diagnosis was defined by age (> 35 yrs), white blood cells (WBC; > 30 for B-ALL, > 100 for T-ALL), and CG (Ph+, MLL rearranged, -7, +8, complex, low hypodiploid, and near triploid). Events included morphologic or MRD recurrence, change in treatment due to inadequate response, death from any cause, or secondary malignancy. Frequencies of characteristics between groups were compared using a Fisher exact test. Cox proportional hazards (PH) models were used to investigate associations between variables. A test of PH was used to assess the impact of time on the association between MRD and outcome, in which MRD was modeled as a time-dependent covariate with left-truncation. Clinical follow-up was updated as of June 2015. Results: We identified 142 pts for this analysis: 18% T-ALL, 73% > 35 yrs, 24% had high WBC (6 unknown), and 48% had high-risk CG, 71% of which (34% of total) were Ph+ (11 unknown). Sixty-five pts (46%) underwent hematopoietic cell transplantation (HCT) in first remission (CR1): 32% with reduced-intensity and 68% with myeloablative conditioning. All Ph+ pts received TKI with hyperCVAD: 23 (48%) received imatinib and 25 (52%) received dasatinib. Median time of 1st MRD assessment (relative to start of treatment) was 37 days, with 27% occurring by 21 days and 85% by 90 days; 42% were MRDNeg at 1stassessment, 26% became MRDNeg later, and 32% did not become MRDNeg during treatment with hyperCVAD. Incidences of age > 35 yrs (P = 1), high-risk CG (P = 0.08), Ph+ (P = 0.72), and high WBC (P = 0.38) were not significantly different in MRDNeg pts. HCT in CR1 was more common in MRDNeg pts (P = 0.05). In Cox PH models adjusted for HCT in CR1, CG, and WBC, MRDNeg pts had significantly better overall survival (OS; hazard ratio [HR] 0.43, 95% confidence interval [CI] 0.23-0.81; P = 0.01; 48 events) and event-free survival (EFS; HR 0.27, 95% CI 0.16-0.46; P < 0.01; 84 events). Through an exploratory landmark analysis, the benefit of MRDNeg on EFS became more pronounced after 8 weeks: pts who were MRDNeg by 8 weeks had significantly better EFS (HR 0.53, 95% CI 0.32-0.89; P = 0.02) than those who were not. Further, achieving MRDNeg earlier during treatment was associated with better EFS. In a test of PH on the time-dependent Cox PH model, time to MRDNeg had a significant impact on the association between MRD status and EFS (P = 0.02) but not OS (P = 0.19). This is depicted in Fig 1, where being MRDNeg earlier after treatment initiation is associated with a smaller beta (i.e., significantly less hazard for an event). Conclusions: MRDNeg is an independent predictor of superior OS and EFS in adults receiving hyperCVAD for ALL. Further, achieving MRDNeg earlier during treatment was associated with better EFS. When considering the time-dependent nature of MRD status relative to EFS, 8 weeks after initiation of hyperCVAD may represent an important prognostic time point. If confirmed in an independent dataset, this may prove to be a useful surrogate in both routine clinical practice and future clinical trials with this regimen. Disclosures Cassaday: Pfizer: Research Funding; Seattle Genetics: Research Funding.

Background Entospletinib (GS-9973) is an orally bioavailable, selective inhibitor of spleen tyrosine kinase (Syk). Syk is a mediator of B-cell receptor signaling in normal and transformed B-cells. Targeting the B-cell receptor (BCR) signaling pathway has been a successful therapeutic strategy for chronic lymphocytic leukemia (CLL), with both ibrutinib, an inhibitor of BTK (BTKi) and idelalisib, an inhibitor of PI3Kdelta (PI3Ki), approved for this indication. Entospletinib activity in CLL was recently reported, and preclinical data suggested that entospletinib may be effective even in the context of resistance to BTK therapy, including that conferred by activation of PLCγ2. (Liu, Blood -2015-02-626846) Methods GS-US-339-0102 is an ongoing phase2 trial of entospletinib in CLL and NHL (NCT01799889). The study protocol was amended to add 40 patients in each of 2 CLL cohorts who have been previously treated with BCR signaling pathway (BTK/PI3K) inhibitors. These patients were treated with entospletinib monotherapy (400mg BID) and evaluated using modified Hallek/IWG-CLL criteria every 2-3 months as previously described in Sharman, Blood 2015:125(5). Results As of July 20, 2015, 8 patients with preceding BCR pathway signaling inhibitor treatment have been enrolled, 5 with preceding BTKi therapy (4 with ibrutinib, 1 with AVL-292) and 3 with preceding PI3Ki therapy (idelalisib). The median duration of preceding BTKi treatment was 51 weeks (range 2-85 weeks) and the median duration of preceding PI3Ki treatment was 106 weeks (range 74-168 weeks). Two patients had progressed on prior BTKi and 2 were intolerant (cause missing for 1 patient), while 2 patients progressed on PI3Ki and 1 was intolerant. All 5 patients with preceding BTKi and 2 out of 3 patients with prior PI3Ki remain on entospletinib treatment. Of the 5 patients who were previously treated with BTKi, the ongoing duration of treatment with entospletinib is 8, 8, 13, 25, and 39 weeks. For the 3 patients with preceding PI3Ki, two patients have ongoing treatment of 18 and 26 weeks; one patient stopped treatment and died after 23 weeks due to a cardiac arrest that is not believed to be related to the study drug. The most common treatment-emergent AEs (N=number; any Grade/≥Gr 3, independent of causality) were decreased appetite (3/0), contusion (2/0), dyspepsia (2/0), fatigue (2/0), dehydration (1/1), cardiac arrest (1/1); common laboratory abnormalities were anemia (5/1), neutropenia (4/1), thrombocytopenia (3/2), increased lipase (1/1). Early responses were seen with entospletinib treatment (3 partial response (PR), 1 stable disease, & 3 patients were too early to evaluate) and 1 PD. PR occurred in 1 BTKi and 2 PI3Ki previously treated patients. One patient with preceding PI3Ki developed progressive disease after 8 weeks. Conclusions Early experience from this trial with ongoing enrollment demonstrates that entospletinib has clinical activity following therapy with either BTKi or PI3Ki. No additional safety signals were seen from earlier studies. Additional investigation of treatment with entospletinib following progression with B-cell receptor signaling pathway inhibitors is warranted. Disclosures Sharman: Celgene Corporation: Consultancy, Research Funding; TG Therapeutics, Inc.: Research Funding; Gilead: Consultancy, Honoraria, Research Funding, Speakers Bureau; Pharmacyclics: Consultancy, Honoraria, Research Funding; Roche: Research Funding; Calistoga: Honoraria; Janssen: Research Funding. Shustov:Celegene, BMS: Consultancy, Honoraria, Research Funding. Smith:celegene, spectrum, genentech: Honoraria. Boyd:US Oncology: Research Funding; Celgene: Speakers Bureau; Genentech, Inc.: Research Funding. Kolibaba:Gilead: Consultancy, Research Funding; Seattle Genetics, Inc.: Research Funding; Acerta: Research Funding; Celgene: Research Funding; Genentech: Research Funding; Takeda Pharmaceuticals International Co.: Research Funding; GSK: Research Funding; Janssen: Research Funding; Pharmacyclics: Research Funding; TG Therapeutics: Research Funding. Abella:Gilead: Employment. He:Gilead Sciences: Employment. Eng:Gilead: Employment. Hu:gilead: Employment. Reddy:gilead: Employment. Mitra:Gilead: Employment. Yasenchak:Seattle Genetics, Inc.: Research Funding.

Background High dose therapy and autologous stem cell transplantation (ASCT) can improve outcomes for patients with mantle cell lymphoma (MCL), yet relapse ultimately occurs in the majority of patients. Maintenance rituximab (MR) administered after induction chemotherapy has been shown to improve overall survival (OS), but limited comparative data are available regarding the impact of MR following ASCT. We report the impact of MR on outcomes following ASCT in a large series of patients with MCL. Methods One hundred sixty four consecutive patients with MCL that underwent ASCT for MCL at our center between November 1995 and May 2011 were included in this retrospective analysis. Patients that received MR after ASCT were compared to patients that did not receive maintenance rituximab after ASCT (no-MR). Two patients underwent tandem autologous/allogeneic stem cell transplants and were excluded from analysis; inadequate follow-up data precluded the evaluation of MR administration in an additional 5 patients. MR was treated as a time-dependent covariate to account for the variability in the time to initiation after ASCT. Statistical significance of differences in event rates between the MR and no-MR groups was evaluated with the Cox proportional hazards regression model. Two-sided p-values less than 0.05 were considered statistically significant. Results A total of 157 patients met the above criteria and were evaluated in this study. MR was administered to 50 (32%) patients and the remaining 107 (68%) patients received no MR after ASCT. Median age at the time of ASCT was 58 (range 35–71). All patients in the MR group had received rituximab prior to ASCT, whereas 13 of the 107 patients in the no-MR group had no prior rituximab (p = 0.01). Patients in the MR group were more likely to have had chemo-sensitive disease (p = 0.05) and to have undergone ASCT during first remission (p = 0.0001) and in complete remission (CR) (p = 0.0003). Patients in the no-MR group were more likely to have received radio-immunotherapy based conditioning (p < 0.0001). The groups were well matched for simplified MIPI score (sMIPI) at the time of diagnosis (p = 0.50) and at ASCT (p = 0.88). A median of 8 (range 1 to 16) doses of MR was administered at a dose of 375 mg/m2. MR was initiated at a median of 77 days after ASCT (range 27 to 287) and the last dose was administered at a median of 271 days after ASCT (range 55 to 1074). The most common dosing schedules included weekly dosing for 4 weeks for two cycles separated by 6 months (n = 15), monthly dosing (n = 8), and every 3-month dosing (n = 7); a variety of dosing schedules were used in the remaining cases (n = 20). Grade 4 neutropenia was observed in 16 of 47 evaluable patients (34%) in the MR group, and 16 of 87 evaluable patients (18%) in the no-MR group (p = 0.04). Granulocyte colony stimulating factor (GCSF) was administered for neutropenia in 15 of 47 evaluable patients (32%) in the MR group, and 10 of 85 evaluable patients (12%) in the no-MR group (p = 0.005). MR was associated with a significantly prolonged PFS (HR 0.33, p = 0.0005) and OS (HR 0.40, p = 0.01) following a multivariate adjustment (Table 1) with a median follow up of 4.75 years. Likewise, in a landmark analysis limited to patients alive and without progression at day 100 after ASCT (n = 147), 3-year PFS and OS were 78% and 86%, respectively, in the MR group and 59% and 71%, respectively, in the no-MR group (Figure 1). Conclusion These data suggest that MR administered following ASCT improves both PFS and OS for patients with MCL with an associated increase in the risk of severe neutropenia and consequent use of GCSF. Randomized, prospective trials are needed to confirm these findings and establish post-ASCT MR as standard of care in treating MCL. Table 1. Multivariate Cox proportional hazards modeling using maintenance rituximab as a time-dependent covariate Progression Free Survival1 Overall Survival2 HR p-value HR p-value Maintenance rituximab 0.33 (0.18 – 0.62) 0.0005 0.40 (0.20 – 0.81) 0.01 1Adjusted for: Age, B-symptoms, MIPI at time of ASCT, disease status at ASCT, chemo-sensitivity, ASCT in first remission, conditioning regimen 2Adjusted for: Age, disease status at ASCT, chemo-sensitivity, ASCT in first remission, conditioning regimen Figure 1. Kaplan-Meier plots using landmark of day 100 after ASCT for (A) progression free survival and (B) overall survival Figure 1. Kaplan-Meier plots using landmark of day 100 after ASCT for (A) progression free survival and (B) overall survival Disclosures Off Label Use: Rituximab as maintenance therapy after autologous stem cell transplantation for mantle cell lymphoma.

Background: Aggressive B-cell non-Hodgkin lymphomas (B-NHL) harboring MYC oncogene abnormalities carry a poor prognosis and frequently relapse after standard front-line therapy. However, little is known about the outcomes following these relapses. Multiple series have suggested that survival is very poor, but detailed descriptions are generally lacking. We sought to examine this under-described yet frequent scenario. Methods: We performed a retrospective analysis of our center’s experience under an IRB-approved protocol. Patients included those with MYC copy number alteration (CN) or gene rearrangement (GR) as detected by fluorescence in situ hybridization and/or metaphase cytogenetics that did not meet diagnostic criteria for Burkitt lymphoma and who experienced initial treatment failure (ITF): relapse after or unable to achieve complete remission (CR) following upfront therapy. Frequencies of characteristics between groups were compared using a chi-square test. Kaplan-Meier plots and Cox proportional hazard models were used to investigate associations between variables. Clinical follow-up was updated as of June 2014. Results: We identified 43 pts with relapsed/refractory B-NHL and a MYC gene abnormality, 31 (72%) of which were MYC GR. Of these 31, 18 (64%) were “double-hit” lymphomas with concurrent BCL2 GR, plus another 2 (7%) that also possessed BCL6 GR (“triple-hit”; BCL2/BCL6 data missing from 3). There were no significant differences in overall survival (OS) from ITF between MYC CN, MYC-only GR, and double-/triple-hit (p = 0.73). Additional clinical features at initial diagnosis included median age of 60 years (yrs) (range: 19-72 yrs), stage III-IV disease in 84% (n = 36), elevated LDH in 83% (n = 24; missing data from 14), and B symptoms in 42% (n = 18). Median time from diagnosis until ITF was 6 months (mo) (range: 1-41 mo). Median follow-up from ITF of surviving pts was 8 mo (range: 2-66 mo). Initial chemotherapy consisted of CHOP in 56% (n = 24), while 35% (n = 15) received a more intense regimen: hyperCVAD (n = 7), dose-adjusted EPOCH (n = 6), or CODOX-M/IVAC (n = 2); all but 1 pt received rituximab (R) with initial therapy. There was no significant difference in the use of CHOP vs intensified regimens with regard to the presence of MYC CN (33% vs 20%, respectively) or MYC GR (67% vs 80%, respectively; p = 0.37). However, 1-yr OS from ITF among those who received CHOP upfront was significantly higher than those who received intensified upfront therapy (34% vs 0%, p = 0.01; Figure 1). CHOP was used more frequently among those who later received ICE salvage (n = 21) than cytarabine (Ara-C)-based salvage (n = 10; 71% vs 40%, respectively; p = 0.09). The rates of subsequent stem cell transplantation (SCT) following ICE and Ara-C were comparable (57% vs 40%, respectively; p = 0.37). R was included in all but 1 pt who received Ara-C. Pts who received ICE had a significantly higher 1-yr OS from ITF than those treated with Ara-C (28% vs 8%, p = 0.01; not shown). 1-yr OS from ITF was significantly better among the 17 pts (40%) who were able to undergo autologous (auto) SCT than the 22 (51%) who did not (38% vs 7%, respectively; p = 0.02; Figure 2). Four pts (9%) received an allogeneic (allo) SCT for their initial salvage SCT and were analyzed separately: Three pts relapsed at 1, 4, and 8 mo post-SCT, while the fourth died in CR 3 yrs later. Rates of SCT use were comparable for pts who initially received CHOP (50%) and those treated with intensified initial therapy (60%; p = 0.54). All but 1 pt in this cohort were treated with the intent of undergoing SCT. Six pts (14%) had confirmed central nervous system (CNS) relapse, 1 of whom received CNS prophylaxis during initial therapy. Among these, 4 died within 6 mo of ITF and 1 was lost to follow-up with progressive disease only 2 mo after ITF. The remaining pt underwent auto SCT in CR and is alive but with only 1 mo of follow-up. Conclusions: We have described the outcomes of one of the largest cohorts of relapsed/refractory MYC+ B-NHL reported to date. Though intensified initial therapy may improve outcomes upfront, pts for whom these regimens fail do exceedingly poorly. Pts unable to undergo SCT also have exceptionally dismal outcomes. These subsets of pts in particular should be offered novel therapies in the context of clinical trials. Further, more aggressive initial therapies including consolidative SCT are worth studying since the outcomes after ITF are so poor. Figure 1 Figure 1. Figure 2 Figure 2. Disclosures Gopal: Seattle Genetics: Consultancy, Honoraria, Research Funding, Speakers Bureau; Takeda/Millennium: Honoraria, Research Funding, Speakers Bureau; Gilead: Research Funding; Janssen: Research Funding; Pfizer: Consultancy, Honoraria, Research Funding; BMS: Research Funding; Piramal: Research Funding; Teva: Research Funding; Spectrum: Research Funding; BioMarin: Research Funding; Merck: Research Funding; Emergent: Research Funding.

Background: Autologous stem cell transplantation (ASCT) is commonly employed in the treatment of mantle cell lymphoma (MCL), though long-term remission following this intervention is relatively uncommon, particularly for patients with relapsed/refractory disease. We hypothesized that high-dose radioimmunotherapy-(RIT) based conditioning prior to ASCT could improve outcomes based on the radiosensitivity of MCL and reduced cross-resistance with chemotherapy. Methods: We evaluated the outcomes of patients with MCL treated with myeloablative conditioning using iodine-131 (131I) conjugated to the anti-CD20 antibody tositumomab with or without additional chemotherapy followed by ASCT on 4 sequential prospective clinical trials. These trials included single agent RIT, RIT + etoposide + cyclophosphamide, and RIT + fludarabine. We retrospectively identified a comparator group of patients at our institution undergoing ASCT for MCL without RIT, using conditioning regimens including carmustine, etoposide, cytarabine, and melphalan (BEAM); busulfan, melphalan, and thiotepa (BuMelT); and 12 Gy of total body irradiation (TBI) plus cyclophosphamide with or without etoposide. We described and compared the outcomes from each group including differences in event rates evaluated by the Cox proportional hazards regression model. To account for imbalanced covariates between subgroups, adjusted estimates of survival were generated (Storer, et al., Lifetime Data Anal, 2008, p. 484). Follow-up was updated as of October 2013. Results: From November 1995 to May 2011, 162 sequential MCL patients received high-dose therapy and ASCT at our center, including 61 (38%) who received RIT-based conditioning. RIT patients received a median of 19.8 GBq (534 mCi; range: 7.6-40.7 GBq [205-1100 mCi]) of 131I to deliver a median of 25 Gy (range: 20-27) absorbed dose to critical organs. Median follow-up from ASCT for all surviving patients was 5.1 yrs (range: 0.3-17.1). Patients treated with RIT-based ASCT were less likely to be in first remission (48% vs 72%; p = 0.002), be in complete remission (CR) at ASCT (26% vs 61%; p < 0.001), or have chemosensitive disease (84% vs 96%; p = 0.006) compared to controls. The 2-year, 5-year, and median PFS were 66%, 49%, and 64 months (respectively) for the control group compared to 70%, 45%, and 54 months (respectively) for the RIT group (p = 0.77; see Table). The 2-year, 5-year, and median OS were 76%, 64%, and 126 months (respectively) for the control group compared to 82%, 62%, and 80 months (respectively) for the RIT group (p = 0.75; see Table). Multivariate analysis (adjusting for chemosensitivity, remission status, ASCT in first remission, and age) indicated that RIT-based conditioning was associated with a reduced risk of mortality and treatment failure (i.e., death or relapse; see Table and Figure). Furthermore, the relative benefit of RIT increased with worsening pre-ASCT disease status (from CR to partial remission to stable/progressive disease), with HRs for mortality 1.1, 0.53, and 0.04, and HRs for treatment failure 1.2, 0.38, and 0.07 (respectively). Incidences were comparable between the RIT and control groups in terms of non-relapse mortality (NRM) (7% vs 8%, respectively) and secondary malignancies (9.8% vs 12%), including acute myeloid leukemia or myelodysplasia (4.9% vs 3%). Conclusions: RIT-based conditioning is associated with improved outcomes following ASCT for MCL after controlling for imbalances in important risk factors, with the greatest benefit among patients with more advanced disease. Rates of NRM and secondary malignancies were comparable with both approaches. These data support the further study of high-dose RIT in a risk-adapted approach to ASCT for MCL. Table: Univariate and multivariable comparison of high-dose RIT-based vs conventional ASCT. Comparison ASCT Conditioning Treatment Failure Overall Mortality HR (95% CI) P HR (95% CI) P Univariate Control 1 - 1 - RIT 1.01 (0.69-1.6) 0.77 1.1 (0.67-1.8) 0.75 Multivariable Control 1 - 1 - RIT 0.47 (0.27-0.79) 0.005 0.49 (0.28-0.86) 0.01 Figure: Estimated PFS after adjusting for chemosensitivity, remission status, ASCT in first remission, and age following high-dose RIT-based or conventional (Control) ASCT for MCL. Figure 1 Figure 1. Disclosures Off Label Use: 131I-tositumomab is not FDA approved for autologous stem cell transplant conditioning.. Gopal:Seattle Genetics: Consultancy, Honoraria, Research Funding, Speakers Bureau; Takeda: Honoraria, Research Funding, Speakers Bureau; Janssen: Research Funding; Pfizer: Consultancy, Research Funding; BMS: Research Funding; Gilead: Research Funding; Spectrum: Research Funding; Teva: Research Funding.

[Graphic][1] Background: InO is a humanized anti-CD22 antibody conjugated to calicheamicin. CD22 is expressed on the majority of cells derived from patients (pts) with B-cell ALL. An initial study suggested InO efficacy and tolerability in ALL (Kantarjian, et al. Cancer. 2013;119(15):2728-36 ). Aims: This ongoing study was preceded by phase 1 dose-escalation and expansion cohorts to select the recommended phase 2 dose (RP2D), determined as 1.8 mg/m2/cycle (0.8 mg/m2 on day 1 and 0.5 mg/m2 on days 8 and 15) as an initial starting dose followed by a dose reduction to 1.6 mg/m2/cycle upon achievement of complete response (CR) or CR without absolute neutrophil count (ANC) or platelet recovery (CRi). One dose-limiting toxicity (elevated lipase) was reported at this starting dose; however, dose delays and reductions were subsequently required in 5 patients for AEs (mostly owing to increased aspartate aminotransferase [AST]). Here we report the results of the phase 2 portion of the study which further evaluates the safety and efficacy of this regimen in patients with CD22+ relapsed/refractory ALL in the second and later salvage settings. Methods: Pts aged ≥18 y with CD22+ ALL in second or later salvage and no known central nervous system disease were enrolled. InO was administered in 28-d cycles up to 6 cycles. Adverse event (AE) severity was assessed per Common Terminology Criteria for Adverse Events (CTCAE) v3. CR was defined as 100,000/µL and no extramedullary disease. Blood samples were collected for pharmacokinetic analyses. Results: We report data for 35 pts: median age was 34 y (range, 20–79y); 77% were men; 6 (17%) pts were in salvage 5 or greater; 15 (43%) pts had prior allogeneic stem cell transplant (SCT). CD22 was expressed on a median of 99% blasts (range, 78%–100%); median peripheral blast count was 317.6/µL (range, 0–41,099/µL) and 28 (80%) pts presented with ≥50% bone marrow blasts. Aberrant baseline cytogenetics were reported in 27 (77%) pts including 9 (26%) with Ph+, 9 (26%) with complex cytogenetics (5 aberrations) and 9 (26%) with other aberrations. Three pts had normal cytogenetics at baseline and 5 had insufficient yield/unknown. Median follow-up in surviving pts was 4.4 (range, 0.7–11) months. Thirty-four pts discontinued InO: 17 owing to progressive disease (PD)/relapse or resistant disease; 7 proceeded to SCT (1 relapsed before SCT); 5 owing to AEs (grade [gr] 4 respiratory failure, gr 2 ascites in the setting of global deterioration, gr 2 increased alkaline phosphatase, gr 2 elevated AST and gr 2 increased transaminases); 2 died due to PD; 1 completed 6 cycles of InO and proceeded to maintenance therapy; 1 refused further treatment and 1 proceeded to DLI. InO-related gr ≥3 AEs (≥10% of pts) were thrombocytopenia (31%), neutropenia (26%) and febrile neutropenia (20%). Other gr ≥3 hepatic AEs included increased ALT/ increased transaminases (6%). Venoocclusive disease/sinusoidal obstruction syndrome occurred in 3 pts during the follow-up period: 2 (salvage 2 and 5) post-SCT and 1 (salvage 4) after the start of subsequent therapy. Prestudy SCT was not reported for these 3 pts. Nineteen deaths were reported: leukemia (n=14), hepatic failure/SOS (n=1), pneumonia (n=1), septic shock and graft versus host disease (n=1), subdural hematoma (n=1), and leukemia/liver failure (n=1). The remission rate (CR+CRi) was 65.7% (95% CI, 47.8, 80.9); 18/23 (78%) patients with CR/CRi achieved MRD negativity. Overall, the median time to remission and MRD negativity was 25 d (range, 15–86 d) and 25.5 d (range, 21–80 d), respectively. Six (67%) Ph+ pts and all 13 pts (100%) without peripheral blood blasts at baseline achieved CR/CRi. The median overall survival for the study population was 7.4 months (95% CI, 4.3–9.9). Summary/Conclusion: InO had a tolerable safety profile primarily characterized by hematologic, gastrointestinal and hepatic AEs. Single-agent InO demonstrated encouraging clinical activity in this multiply relapsed/refractory population. Further exploration in CD22+ ALL is ongoing. | Median (range) InO cycles initiated, n | 3 (1–6) | | ------------------------------------------- | ---------------------- | | CR + CRi rate, n (%) [95% CI] | 23 (65.7) [47.8, 80.9] | | CR | 11 (31.4) | | CRi | 12 (34.3) | | MRD negative rate in pts with CR/CRi, n (%) | 18 (78.2) | | CR (n=11) | 8 (73) | | CRi (n=12) | 10 (83) | | OS (95% CI) at 12 mo, % | 26 (10, 50) | | Median (95% CI) OS, mo | 7.4 (4.3, 9.9) | Table 1 Disclosures Advani: Pfizer Inc: Research Funding. Kantarjian: Pfizer Inc: Research Funding. DeAngelo: Pfizer Inc: Advisory Board Other. Ananthakrishnan: Pfizer Inc: Employment. Liau: Pfizer Inc.: Employment. Vandendries: Pfizer Inc.: Employment. Stock: Amgen: Consultancy; Sigma Tau: Consultancy; Jazz: Consultancy; Seattle Genetics: Consultancy; UpToDate: Honoraria; American Board of Internal Medicine: Honoraria. [1]: /embed/inline-graphic-2.gif