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Purpose: On the basis of the recent discovery of mutations in Bruton tyrosine kinase (BTK) in follicular lymphoma, we studied their functional properties. Experimental Design: We identified novel somatic BTK mutations in 7% of a combined total of 139 follicular lymphoma and 11 transformed follicular lymphoma cases, none of which had received prior treatment with B-cell receptor (BCR) targeted drugs. We reconstituted wild-type (WT) and mutant BTK into various engineered lymphoma cell lines. We measured BCR-induced signal transduction events in engineered cell lines and primary human follicular lymphoma B cells. Results: We uncovered that all BTK mutants destabilized the BTK protein and some created BTK kinase-dead mutants. The phospholipase C gamma 2 (PLCγ2) is a substrate of BTK but the BTK mutants did not alter PLCγ2 phosphorylation. Instead, we discovered that BTK mutants induced an exaggerated AKT phosphorylation phenotype in anti-Ig-treated recombinant lymphoma cell lines. The short hairpin RNA–mediated knockdown of BTK expression in primary human nonmalignant lymph node–derived B cells resulted in strong anti-Ig-induced AKT activation, as did the degradation of BTK protein in cell lines using ibrutinib-based proteolysis targeting chimera. Finally, through analyses of primary human follicular lymphoma B cells carrying WT or mutant BTK, we detected elevated AKT phosphorylation following surface Ig crosslinking in all follicular lymphoma B cells, including all BTK-mutant follicular lymphoma. The augmented AKT phosphorylation following BCR crosslinking could be abrogated by pretreatment with a PI3Kδ inhibitor. Conclusions: Altogether, our data uncover novel unexpected properties of follicular lymphoma–associated BTK mutations with direct implications for targeted therapy development in follicular lymphoma. See related commentary by Afaghani and Taylor, p. 2123

Background There is an unmet need for antithrombotic treatments for venous thromboembolic disease that do not increase bleeding risk. Selectins are cell adhesion molecules that augment thrombosis by activating immune cells to initiate the coagulation cascade. GMI‐1271, a potent small‐molecule E‐selectin antagonist, has been shown in mouse models to decrease thrombus burden with a low risk of bleeding. Methods A first‐in‐human study of GMI‐1271 was conducted to assess its safety, tolerability, and pharmacokinetic (PK) profile. As a secondary end point, biomarkers of coagulation, cell adhesion, and leukocyte/platelet activation were evaluated. Aims 1 and 2 were performed in healthy volunteers and evaluated single and multiple doses of the study drug, respectively. Aim 3 included 2 patients with isolated calf‐level deep vein thrombosis (DVT). Results GMI‐1271 showed consistent PK parameters for doses ranging from 2 to 40 mg/kg. Plasma levels increased in a linear manner with respect to dose, while clearance, volume of distribution, and half‐life were not dose dependent. No accumulation was seen with multiple consecutive doses. No serious adverse events (grade 3 or 4) were reported. Biomarker analysis demonstrated a trend in reduction of soluble E‐selectin (sEsel) levels with GMI‐1271 exposure, while exposure did not impact laboratory testing of coagulation. Two patients with calf vein DVT were treated with GMI‐1271 and demonstrated rapid improvement of symptoms after 48 hours, with repeat ultrasound showing signs of clot resolution. Conclusions We demonstrate that GMI‐1271 is safe in healthy volunteers and provide proof of concept that an E‐selectin antagonist is a potential therapeutic approach to treat venous thrombosis.

Diffuse large B-cell lymphoma featuring overexpression of MYC and B-Cell Lymphoma 2 (double expressor lymphoma, DEL) is associated with poor outcomes. Existing evidence suggesting improved outcomes for DEL with the use of more intensive regimens than R-CHOP is restricted to younger patients and based on limited evidence from low patient numbers. We retrospectively evaluated the impact of intensive frontline regimens versus R-CHOP in a multicenter analysis across 7 academic medical centers in the United States. We collected 90 cases of DEL, 46 out of 90 patients (51%) received R-CHOP and 44/90 (49%) received an intensive regimen, which was predominantly DA-EPOCH-R. Treatment cohorts were evenly balanced for demographics and disease characteristics, though the intensive group had a higher lactate dehydrogenase (LDH, 326 vs. 230 U/L p = 0.06) and presence of B-symptoms (50% vs. 22%, p = 0.01) compared to the R-CHOP cohort. There was no difference in PFS (median 53 vs. 38 months, p = 0.49) or overall survival (67 vs. not reached months, p = 0.14) between the R-CHOP and intensive therapy cohorts, respectively. On multivariate analysis, intensive therapy was associated with a hazard ratio of 2.35 (95% CI 0.74-7.41), though this was not statistically significant. Additionally, a subgroup analysis of intermediate high-risk lymphoma defined by IPI ≥3 did not identify a difference in survival outcomes between regimens. We conclude that in our multi-center cohort there is no evidence supporting the use of intensive regimens over R-CHOP, suggesting that R-CHOP remains the standard of care for treating DEL.

Mantle cell lymphoma (MCL) is an incurable intermediate-grade lymphoma representing 5-6% of non-Hodgkin's lymphomas diagnosed in the United States. The introduction of inhibitors of Bruton's tyrosine kinase (BTK) into targeted therapy for MCL has significantly improved outcomes in patients with relapsed/refractory (R/R) disease. Since the initial approval of the first-generation inhibitor, ibrutinib, several second-generation inhibitors have been explored. Acalabrutinib, a second-generation BTK inhibitor, has demonstrated impressive efficacy in clinical trials along with a safety profile that thus far appears improved compared to ibrutinib. The results of a Phase II trial in patients with R/R MCL led to the approval of acalabrutinib in this patient population while fueling further exploration of acalabrutinib in several ongoing clinical trials.

Successful treatment of relapsed/refractory and rare subtypes of lymphomas remains a therapeutic challenge. Though the use of tumor profiling is increasing, little is described about how providers ultimately utilize this information in clinical decision-making. We reviewed 92 adult lymphoma patients who underwent an IRB-approved tumor sequencing protocol at the University of Michigan, MI-ONCOSEQ. Of this cohort, 60 had a targeted treatment suggested by their test results, and 11 patients ultimately underwent the MI-ONCOSEQ recommended therapy. One obtained complete response based on precision treatment recommendations. The two main barriers for targeted treatment utilization included inopportune timing (the patient either was sequenced too early or too late in their disease course) and clinical trial availability. While this study demonstrates the success of sequencing lymphomas for the identification of novel therapies, it also underlines the clinical challenges, namely the optimal timing and availability of trials, inherent in the successful application of this technology.

Background: All-trans retinoic acid (ATRA) serves as the backbone of the management of patients with acute promyelocytic leukemia (APL), with guidelines recommending the initiation of ATRA as soon as APL is suspected. As a regional referral center for patients with acute leukemia, those who are suspected of having APL are often transferred to our facility. However, many referring centers are unable to initiate treatment using ATRA. We conducted an exploratory analysis of the clinical availability of ATRA and the factors limiting access to this critical drug. Patients and Methods: The United States was divided into 6 geographic regions: Northwest, Southwest, Central, Southeast, Northeast, and the Great Lakes. Twenty hospitals were randomly selected from states within each of these regions and were surveyed as to whether they typically treated patients with acute leukemia, the availability of ATRA at their institution, and reported reasons for not stocking ATRA (if not available). Results: Less than one-third of hospitals queried (31%) had ATRA in stock. Neither the size of the hospital nor the hospital’s status as academic versus nonacademic (53% vs 31%; P=.08) influenced ATRA availability. Of the hospitals that referred patients with APL, only 14% (7/49) had ATRA readily available. Hospitals that treated patients with APL were more likely to have ATRA available than referring centers (58% vs 14%; P=.000002). Conclusions: Nearly two-thirds of the hospitals surveyed that cared for patients with acute leukemia do not have ATRA immediately available. Moreover, the vast majority of hospitals that refer patients to other centers do not have ATRA. These findings should spur investigation into the impact of immediate ATRA availability on the morbidity and mortality of patients with APL. A call by hematologists nationwide to their formulary committees is warranted to ensure that this lifesaving medication is available to patients suspected of having APL.

Tenalisib (RP6530), a dual phosphoinositide 3-kinase &delta, /&gamma, inhibitor was evaluated in a phase I/Ib study for maximum tolerated dose (MTD), pharmacokinetics, and efficacy in patients with relapsed/refractory peripheral and cutaneous T-Cell Lymphoma (TCL). Histologically confirmed (TCL) patients, with &ge, 1 prior therapy received Tenalisib orally in a 28-day cycle in doses of 200 to 800 mg twice daily (800 mg in fasting and fed state) in escalation phase (n = 19) and 800 mg twice daily (fasting) in expansion phase (n = 39). The most frequently reported treatment emergent adverse events (TEAE) and related TEAE were fatigue (45%) and transaminase elevations (33%), respectively. Most frequently reported related Grade &ge, 3 TEAE was transaminase elevation (21%). Two dose-limiting toxicities occurred in the 800 mg fed cohort, hence, 800 mg fasting dose was deemed MTD. Tenalisib was absorbed rapidly with a median half-life of 2.28 h. Overall response rate in 35 evaluable patients was 45.7% (3 complete response (CR), 13 partial response (PR)) and median duration of response was 4.9 months. Responding tumors showed a marked downregulation of CD30, IL-31 and IL-32&alpha, With an acceptable safety and promising clinical activity, Tenalisib can be a potential therapeutic option for relapsed/refractory TCL. Currently, a phase I/II combination study with romidepsin is ongoing.

In relapsed/refractory Hodgkin lymphoma (R/R HL), immunotherapies such as the anti-programmed death-1 inhibitor pembrolizumab have demonstrated efficacy as monotherapy and are playing an increasingly prominent role in treatment. The CD30/CD16A-bispecific antibody AFM13 is an innate immune cell engager, a first-in-class, tetravalent antibody, designed to create a bridge between CD30 on HL cells and the CD16A receptor on natural killer cells and macrophages, to induce tumor cell killing. Early studies of AFM13 have demonstrated signs of efficacy as monotherapy for patients with R/R HL and the combination of AFM13 with pembrolizumab represents a rational new treatment modality. Here, we describe a phase 1b, dose-escalation study to assess the safety and preliminary efficacy of AFM13 in combination with pembrolizumab in patients with R/R HL. The primary objective was estimating the maximum tolerated dose; the secondary objectives were to assess safety, tolerability, antitumor efficacy, pharmacokinetics, and pharmacodynamics. In this heavily pretreated patient population, treatment with the combination of AFM13 and pembrolizumab was generally well tolerated, with similar safety profiles compared to the known profiles of each agent alone. The combination of AFM13 with pembrolizumab demonstrated an objective response rate of 88% at the highest treatment dose, with an 83% overall response rate for the overall population. Pharmacokinetic assessment of AFM13 in the combination setting revealed a half-life of up to 20.6 hours. This proof-of-concept study holds promise as a novel immunotherapy combination worthy of further investigation. This phase 1b study was registered at www.clinicaltrials.gov as NCT02665650.

7505 Background: MCL is a rare lymphoma without a standard of care but several regimens have demonstrated clinical activity, the majority based on traditional chemotherapy. We hypothesized that adding venetoclax (V) to R2 would be safe and effective in MCL pts irrespective of age, morphology or stage. Here we present safety and efficacy data from the on-going phase 1b study of R2 + V in pts with newly diagnosed MCL. Methods: This multi-center phase 1 study (NCT03523975) enrolled pts aged ≥18 yrs with untreated MCL. The primary objective was to characterize the safety and tolerability of R2 + V and determine the MTD. During induction (12 months (m)) pts received lenalidomide (L) 20 mg daily on day 1-21, Rituximab (R) was given weekly during c1 then on day 1 of every even cycle, V was escalated over 4 weeks to 400 mg beginning day 8. Each cycle is 28 days (d). The DLT period was 42 d beginning C1D8. In maintenance, R every 8 weeks for 36m, L at 10 mg or half of last dose during induction for 24 m and V for minimum 12 m. No pts have been transplanted. Pts with progression (PD) came off study. MRD was analyzed in parallel with scans during induction by clonoSEQ assay (Adaptive Biotechnologies). Results: As of Feb. 1st, 2021, we have enrolled all 28 planned pts on study. Pt characteristics/responses are summarized in Table. Among the 28 pts who have received at least one dose, the median treatment duration so far is 278d (IQR 170-560), with 24 pts still on treatment (Tx). 1 pt is off from a unrelated condition. All pts escalated to V 400 mg w/o any DLTs noted. Treatment-emergent adverse events (TEAEs) were reported in 100% of pts, and grade 3+ TEAEs were reported in 26 (93%) patients. The most common all-grade TEAEs (≥50% of pts), regardless of relationship to study Tx, were fatigue, neutropenia and diarrhea. Grade ≥3 TEAEs reported in ≥50% pts were neutropenia (68%) and thrombocytopenia (50%). No pts have withdrawn or d/c Tx due to AEs. There was one grade 5 event, in a non-evaluable pt, related to a PE that occurred prior to DLT period. In the 28 evaluable pts the ORR (CR/PR) was 96% (27/28 pts) with CR/CRu of 89%. Of the responding pts, two had PD, one w/ CR and one w/ PR. All pts with PD had baseline TP53 mutation. MRD testing was successful in all pts. At time of submission 20 of 28 (71%) were MRD - at 10-6. Conclusions: Interim results show that at the MTD the combination of V 400 mg daily, L 20 mg, with R is safe with a manageable toxicity profile and a high ORR and MRD - in pts with newly diagnosed MCL. Safety data is consistent with the AE profile noted for each drug without any unexpected or unique AEs. Updated results including BH3 profiling will be presented at the meeting. Clinical trial information: NCT03523975. [Table: see text]

The transcription factor GATA-3, highly expressed in many cutaneous T-cell lymphoma (CTCL) and peripheral T-cell lymphomas (PTCL), confers resistance to chemotherapy in a cell-autonomous manner. As GATA-3 is transcriptionally regulated by NF-κB, we sought to determine the extent to which proteasomal inhibition impairs NF-κB activation and GATA-3 expression and cell viability in malignant T cells. Proteasome inhibition, NF-κB activity, GATA-3 expression, and cell viability were examined in patient-derived cell lines and primary T-cell lymphoma specimens ex vivo treated with the oral proteasome inhibitor ixazomib. Significant reductions in cell viability, NF-κB activation, and GATA-3 expression were observed preclinically in ixazomib-treated cells. Therefore, an investigator-initiated, single-center, phase II study with this agent in patients with relapsed/refractory CTCL/PTCL was conducted. Concordant with our preclinical observations, a significant reduction in NF-κB activation and GATA-3 expression was observed in an exceptional responder following one month of treatment with ixazomib. While ixazomib had limited activity in this small and heterogeneous cohort of patients, inhibition of the NF-κB/GATA-3 axis in a single exceptional responder suggests that ixazomib may have utility in appropriately selected patients or in combination with other agents.

Intravascular large B-cell lymphoma (IVLBCL) is a rare entity, with a generally aggressive course that may vary based on geographic presentation. While a United States (US) registry study showed relatively good outcomes with IVLBCL, clinicopathological and treatment data were unavailable. We performed a detailed retrospective review of cases identified at 8 US medical centres, to improve understanding of IVLBCL and inform management. We compiled data retrieved via an Institutional Review Board-approved review of IVLBCL cases identified from 1999 to 2015 at nine academic institutions across the US. We characterized the cohort's clinical status at time of diagnosis, presenting diagnostic and clinical features of the disease, treatment modalities used and overall prognostic data. Our cohort consisted of 54 patients with varying degrees of clinical features. Adjusting for age, better performance status at presentation was associated with increased survival time for the patients diagnosed in vivo (hazard ratio: 2·12, 95% confidence interval 1·28, 3·53). Based on the data we have collected, it would appear that the time interval to diagnosis is a significant contributor to outcomes of patients with IVLBCL.

This chapter guides the reader on the diagnosis and management of leukocytosis in hospitalized patients.

This chapter guides the reader on the diagnosis and management of thrombocytosis in hospitalized patients.

This chapter guides the reader on the general principles, clinical manifestations, and management of anemia in hospitalized patients.

This chapter guides the reader on the diagnosis and management of eosinophilia in hospitalized patients.

This chapter guides the reader on the diagnosis and management of polycythemia in hospitalized patients.

Influenza morbidity and mortality can be severe and costly. Vaccination rates remain suboptimal in cancer patients due to provider- and patient-related factors. The objective of this study was to evaluate whether low-cost provider- and patient-focused interventions would increase influenza vaccination rates at the University of Michigan Comprehensive Cancer Center (UMCCC). This quality improvement project included all patients without documentation of influenza vaccination prior to their first outpatient appointment during the 2011-2012 and 2012-2013 influenza seasons. The multi-stepped intervention included provider and patient reminders. Influenza vaccination rates were compiled using CPT-4 codes. Same-day (with appointment) vaccination rates during the intervention seasons were compared to historical (2005-2011 seasons) controls; vaccination rates were also compared to contemporary control population at the University of Michigan Health System (UMHS). Reasons for non-adherence with vaccination were explored. The cumulative same-day vaccination rate in eligible adults was 10.1 % (2011-2012) and 9.4 % (2012-2013) compared to an average 6.9 % during influenza seasons 2005-2011. Based on logistic regression analysis, there was a 37.6 % (95 % CI 35-40.3 %) and 56.1 % (95 % CI 40.9-73 %) relative increase in the adult vaccination rate associated with the intervention, with 399 and 697 additional vaccinations, respectively, for each season. During the 2012-2013 season, the UMCCC adult vaccination rate was higher compared to the remainder of that of the UMHS. The intervention was well accepted by providers. Reasons for no vaccination were provider- and patient-related. Increasing provider and patient awareness with a simple, inexpensive intervention was associated with higher influenza vaccination rates at a large academic cancer center. The intervention is permanently implemented during influenza seasons.

Cutaneous T-cell lymphomas (CTCLs) are a heterogeneous group of extranodal lymphomas involving the skin. Diagnosis of the two main subtypes of CTCL-mycosis fungoides (MF) and Sézary syndrome (SS)-is based on the International Society for Cutaneous Lymphomas/European Organization for Research and Treatment of Cancer (ISCL/EORTC) classification system, which utilizes clinical, histopathological, molecular biologic, and immunopathologic features. Risk stratification, based on TNMB (tumor, node, metastasis, and blood) staging, provides prognostic information, with limited-stage disease conferring the longest median overall survival. Skin-directed therapies are preferred in the management of limited-stage disease, whereas advanced-stage disease requires systemic therapies. As the mechanisms of CTCL pathogenesis are increasingly understood, new monoclonal antibodies, checkpoint inhibitors, immunomodulatory agents, and small molecules are under investigation and may provide additional therapeutic options for those with advanced CTCL. This review examines the current landscape of targeted therapies in the treatment of CTCLs.

Advanced classical Hodgkin lymphoma (cHL) is a rare lymphoid disease characterized by the presence of Hodgkin and Reed-Sternberg (HRS) cells. Each year, cHL accounts for 0.5% of all new cancer diagnoses and about 80% are diagnosed with advanced stage disease. Given the significant improvement in cure rates, the focus of treatment has shifted towards minimization of acute and long-term toxicities. PET-adapted strategies have largely been adopted as standard of care in the United States in an attempt to balance toxicities with adequate lymphoma control. However, the appropriate upfront chemotherapy regimen (ABVD versus eBEACOPP) remains controversial.

Background: The DIAL study is testing the efficacy of dual immunomodulation in patients with advanced aggressive B cell non-Hodgkin lymphoma (B-NHL). Sponsored by the Cancer Therapy Evaluation Program (CTEP), the trial combines the use of a programmed cell death protein 1 (PD-1) inhibitor (nivolumab) with an agonist of the CD27 receptor (varlilumab) in a randomized phase 2 design. CD27, a co-stimulatory receptor, regulates T cell activation in the context of T cell receptor (TCR) engagement through interaction with CD70. T cell exhaustion plays a major role in immune evasion in B-NHL. Varlilumab is an agonistic IgG1 monoclonal antibody that recognizes CD27 leading to prevention or reversal of exhaustion in pre-clinical models. Varlilumab also demonstrates direct anti-tumoral activity in xenograft models of human lymphoma cell lines via antibody-dependent cell-mediated cytotoxicity. Phase 1 data supports the safety and tolerability of single-agent varlilumab in advanced hematologic malignancies (NCT01460134). We hypothesize that CD27 activation synergizes with PD-1 inhibition resulting in a superior anti-lymphoma effect compared to PD-1 blockade alone. The study will also evaluate the effect of these agents on tumor and immune cells using immunohistochemistry (IHC), mass cytometry (CyTOF), multiplex ELISA, imaging mass cytometry (IMC), and whole exome sequencing. Methods: The trial is enrolling patients with advanced aggressive B-NHL. Standard inclusion criteria and prior treatment with at least 2 lines of standard therapy are required. Prior autologous stem cell transplant and/or chimeric antigen receptor (CAR) T cell therapy is allowed. Patients with active CNS disease are excluded. Eligible patients are randomized to treatment with single-agent nivolumab (group 1) or dual immunotherapy with nivolumab and varlilumab. Group 1 is allowed to cross-over at the time of progression. Nivolumab will be administered intravenously (IV) every 2 weeks (240 mg) for 4 months followed by monthly dosing thereafter (480 mg). Varlilumab will be given IV every 4 weeks (3 mg/kg). Response assessment will be done by PET-CT scan every 12 weeks. Primary outcome is overall response rate (ORR) according to the LYRIC criteria. The trial will enroll 48 patients per arm, allowing 80% power to detect at least 20% increase in ORR in the experimental arm (group 2) assuming a 25% ORR in the control arm (group 1). The trial is registered (NCT03038672) and open to participation to members of the Experimental Therapeutics Clinical Trials Network (ETCTN) and Early Drug Development Opportunity Program (EDDOP). Figure Disclosures Tun: BMS: Research Funding; Celgene: Research Funding; Curis: Research Funding; TG Therapeutics: Research Funding; Mundi-pharma: Research Funding; DTRM Biopharma: Research Funding. Bartlett:Pharmacyclics: Research Funding; Merck: Research Funding; Incyte: Research Funding; ADC Therapeutics: Membership on an entity's Board of Directors or advisory committees, Research Funding; Pfizer: Research Funding; Millennium: Research Funding; Kite Pharma: Research Funding; Janssen: Research Funding; Immune Design: Research Funding; Affimed: Research Funding; Autolus: Research Funding; Bristol-Myers Squibb: Research Funding; Celgene: Research Funding; Forty Seven: Research Funding; Genentech, Inc.: Research Funding; Gilead: Research Funding. Kline:Merck: Honoraria; Merck: Research Funding. Awan:Janssen: Consultancy; Gilead: Consultancy; Sunesis: Consultancy; Genentech: Consultancy; Abbvie: Consultancy, Speakers Bureau; Pharmacyclics: Consultancy, Research Funding; AstraZeneca: Consultancy, Speakers Bureau. Lazaryan:Kadmon: Consultancy. Ansell:Affimed: Research Funding; Affimed: Research Funding; Bristol-Myers Squibb: Research Funding; Mayo Clinic Rochester: Employment; Affimed: Research Funding; Bristol-Myers Squibb: Research Funding; Bristol-Myers Squibb: Research Funding; Affimed: Research Funding; Affimed: Research Funding; Affimed: Research Funding; LAM Therapeutics: Research Funding; Mayo Clinic Rochester: Employment; LAM Therapeutics: Research Funding; LAM Therapeutics: Research Funding; Seattle Genetics: Research Funding; LAM Therapeutics: Research Funding; Affimed: Research Funding; Bristol-Myers Squibb: Research Funding; LAM Therapeutics: Research Funding; Trillium: Research Funding; Regeneron: Research Funding; Regeneron: Research Funding; Regeneron: Research Funding; Regeneron: Research Funding; Bristol-Myers Squibb: Research Funding; Mayo Clinic Rochester: Employment; Seattle Genetics: Research Funding; Seattle Genetics: Research Funding; Regeneron: Research Funding; Seattle Genetics: Research Funding; LAM Therapeutics: Research Funding; Seattle Genetics: Research Funding; Affimed: Research Funding; Trillium: Research Funding; Trillium: Research Funding; LAM Therapeutics: Research Funding; Trillium: Research Funding; Trillium: Research Funding; Seattle Genetics: Research Funding; Mayo Clinic Rochester: Employment; Regeneron: Research Funding; Mayo Clinic Rochester: Employment; Regeneron: Research Funding; Bristol-Myers Squibb: Research Funding; Mayo Clinic Rochester: Employment; Mayo Clinic Rochester: Employment; Trillium: Research Funding; Seattle Genetics: Research Funding; Seattle Genetics: Research Funding; Mayo Clinic Rochester: Employment; Trillium: Research Funding; Mayo Clinic Rochester: Employment; LAM Therapeutics: Research Funding; Trillium: Research Funding; Seattle Genetics: Research Funding; Bristol-Myers Squibb: Research Funding; Affimed: Research Funding; Bristol-Myers Squibb: Research Funding; Regeneron: Research Funding; Bristol-Myers Squibb: Research Funding; LAM Therapeutics: Research Funding; Regeneron: Research Funding; Trillium: Research Funding. Diefenbach:Bristol-Myers Squibb: Consultancy, Research Funding; Denovo: Research Funding; Genentech: Consultancy, Research Funding; Incyte: Research Funding; LAM Therapeutics: Research Funding; MEI: Research Funding; Merck: Consultancy, Research Funding; Seattle Genetics: Consultancy, Research Funding; Millenium/Takeda: Research Funding; Trillium: Research Funding.

Introduction: Tenalisib (RP6530) is a novel, highly specific, dual PI3K δ/γ inhibitor with nano-molar inhibitory potency at the enzyme and cellular level. PI3K plays a critical role in T-cell development and activation and several studies have validated the PI3K-AKT pathway as a potential therapeutic target in T cell lymphomas. Preliminary results of the ongoing Phase 1/1b T-cell lymphoma (TCL) study demonstrated an acceptable safety profile with encouraging clinical activity in relapsed/refractory TCL (Oki, ASCO 2018 and Iyer, ASH 2018). We now present the final results of the study (NCT02567656). Methods: This study comprised of four-dose escalation cohorts, followed by two dose expansion cohorts at MTD enrolling 20 patients each in PTCL and CTCL cohorts. Patients had histologically confirmed TCL, ECOG PS ≤2, and had received ≥1 prior therapy. Patients received Tenalisib [200 mg BID-800 mg BID (fasting), 800 mg (fed only)] orally until progression or unacceptable toxicity. The primary objectives were to determine the MTD and pharmacokinetic profile. The secondary objective was to evaluate overall response rate (ORR) and duration of response. Responses were evaluated for PTCL and CTCL based on IWG criteria (Cheson 2007) and mSWAT respectively. Adverse events were graded according to CTCAE v4.03. Results: Fifty-eight patients were enrolled in study, 19 in dose escalation and 39 in dose expansion (28 PTCL and 30 CTCL). Median number of prior therapies was 4 (range, 1-15). Safety assessment of 58 patients receiving at least one dose of Tenalisib demonstrated an acceptable safety profile. Treatment related Grade≥3 AEs were elevated ALT/AST (21%), rash (5%), and hypophosphatemia (3%). These events were reversible and managed by withholding study drug. Additionally, in few patients (N=9), steroids were used to manage elevated ALT/AST. There were six treatment related serious adverse events, none of these led to fatal outcome. At end of the study, four (3 CTCL; 1 PTCL) patients who completed minimum 8 cycles of therapy were rolled over to a compassionate use study (NCT03711604) and were followed up. Efficacy assessments demonstrated an ORR of 46% (3 CR and 13 PR) and clinical benefit rate (CR+PR+SD) of 77%. Subset efficacy analysis showed an ORR in PTCL of 47% (3 CR; 4 PR) and in CTCL of 45% (9 PR). The median time to initial response was 1.8 months and was similar in both sub-types. The overall median DOR was 4.91 months (range 0.9-26.6); in PTCL patients the DOR was 6.53 months, (range: 0.97-21.0) and 3.8 months (range: 1.67-25.67) in CTCL patients. In 3 PTCL patients who achieved CR, the median DOR was 19.5 months (range 7.5-21). Conclusion: Tenalisib demonstrated promising clinical activity and an improved safety profile in patients with relapsed/ refractory TCL. Currently, a phase I/II combination study to further evaluate safety and efficacy with romidepsin is ongoing in this target population. Disclosures Iyer: Arog: Research Funding; Bristol-Myers Squibb: Research Funding; Novartis: Research Funding; Seattle Genetics, Inc.: Research Funding; Genentech/Roche: Research Funding; Incyte: Research Funding. Zain:Spectrum: Consultancy; Seattle Genetics: Consultancy. Korman:Genentech: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Glaxo: Honoraria, Membership on an entity's Board of Directors or advisory committees; Immune Pharma: Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Kyowa: Research Funding; Leo: Research Funding; Menlo: Research Funding; Merck: Research Funding; Novartis: Consultancy, Honoraria, Speakers Bureau; Pfizer: Research Funding; Principia: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Prothena: Research Funding; Regeneron: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Rhizen: Research Funding; Sun: Honoraria, Membership on an entity's Board of Directors or advisory committees; Syntimmune: Research Funding; UCB: Research Funding; Valeant: Honoraria, Membership on an entity's Board of Directors or advisory committees; Eli Lilly: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Dermira: Research Funding; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Bristol-Myers Squibb: Research Funding; AbbVie: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Routhu:Rhizen Pharmaceuticals S.A.: Employment. Barde:Rhizen Pharmaceuticals S.A.: Employment. Nair:Rhizen Pharmaceuticals S.A.: Employment. Huen:Galderma Inc: Research Funding; Glaxo Smith Kline Inc: Research Funding; Rhizen Pharmaceuticals: Research Funding; Innate Pharmaceuticals: Research Funding.

Survival following anthracycline-based chemotherapy remains poor among patients with most T-cell lymphoproliferative disorders. This may be attributed, at least in part, to cell-autonomous mechanisms of chemotherapy resistance observed in these lymphomas, including the loss of important tumor suppressors and the activation of signaling cascades that culminate in the expression and activation of transcription factors promoting cell growth and survival. Therefore, the identification of novel therapeutic targets is needed. In an effort to identify novel tumor dependencies, we performed a loss-of-function screen targeting ≈500 kinases and identified polo-like kinase 1 (PLK-1). This kinase has been implicated in the molecular cross-talk with important oncogenes, including c-Myc, which is itself an attractive therapeutic target in subsets of T-cell lymphomas and in high-grade ("double hit") diffuse large B-cell lymphomas. We demonstrate that PLK-1 expression is prevalent among these aggressive lymphomas and associated with c-myc expression. Importantly, PLK-1 inhibtion with the PLK-1 inhibitor volasertib significantly reduced downstream c-myc phosphorylation and impaired BRD4 binding to the c-myc gene, thus inhibiting c-myc transcription. Therefore, volasertib led to a nearly complete loss of c-myc expression in cell lines and tumor xenografts, induced apoptosis, and thus warrants further investigation in these aggressive lymphomas.

Optimal salvage therapy for primary refractory peripheral T-cell lymphomas (PTCL) and the role of hematopoietic stem cell transplant (SCT) remain poorly defined. We conducted a retrospective review of clinical outcomes and prognostic factors in a single-center cohort of 93 patients with primary refractory PTCL, defined as progression during first-line therapy or relapse within 6 months of its completion. Clinical outcomes were poor in this population, with median event-free survival (EFS) of 3.5 months, median overall survival (OS) of 9.1 months, and 34% 3-year survival. Outcomes were comparable in patients who progressed through first-line therapy and patients who achieved CR/PR and subsequently relapsed within 6 months. A majority exhibited high-risk features and had intermediate to high risk IPI, which correlated with inferior outcomes. There was no difference in outcomes between patients who received single-agent salvage regimens and patients who underwent traditional, multi-agent salvage regimens. Thus, participation in well-designed clinical trials should be encouraged in this population. Additionally, there may be a trend toward improved EFS and OS in patients who underwent autologous or allogeneic SCT compared to patients who achieved CR or PR but were not transplanted.

Successful treatment of relapsed/refractory and rare subtypes of lymphomas remains a therapeutic challenge. Though the use of tumor profiling is increasing, little is described about how providers ...

e14645 Background: Despite the increasing availability of targeted and novel therapies, successful treatment of many relapsed/refractory lymphomas remains a challenge. Tumor sequencing is becoming an increasingly available technique to identify potential therapeutic targets; however, there remains considerable uncertainty about the successful application of this data in a “real world” clinical setting. Methods: Herein, we describe 91 lymphoma patients who underwent DNA & RNA sequencing of tumor biopsies via the MIONCOSEQ protocol to identify actionable therapeutic targets. Their charts were reviewed for the clinical use of MIONCOSEQ recommendations. Results: Among the 91 patients were 13 Lymphoma subtypes. Most patients had Stage III/IV disease (68%) at diagnosis, underwent an average of 4 treatments before sequencing (range 0-16) and had approximately 47 distinct molecular alterations (range 2-447). Of the cohort, 60 patients (65%) had actionable targets identified of which 11 ultimately received treatment based on MIONCOSEQ recommendations. The remaining patients did not receive treatment due to multiple reasons: prior CR or on surveillance not requiring treatment (10); death (12); trial ineligibility (4); trial unavailability at the institution (8); patient preference for local treatment (6); and already on alternative treatments (9). Taken as a whole, sequencing late in the disease course and a lack of available clinical trials were identified as barriers for the incorporation of MIONCOSEQ data into clinical practice. Therefore, earlier sequencing and strategies to bolster the availability of targeted therapies may significantly increase the application of genomic data and precision medicine in clinical practice. Conclusions: While next generation sequencing (NGS) is a powerful tool for advancing precision medicine, meaningful clinical application of these results remains a challenge. Our study indicates that early sequencing and improved trial availability could be beneficial in increasing real-world therapeutic options for relapsed/refractory lymphoma. Further research is needed to determine the extent to which a personalized approach, informed by NGS data, improves outcomes.

Desmoid tumors are rare, clonal collections of benign fibrous tissue that exhibit a highly variable clinical course. This article presents a comprehensive review of desmoid tumors and summarizes the current literature pertaining to clinical presentation, diagnostic modalities, pathogenesis, prognostic factors, and management options.

Introduction: Hemophagocytic lymphohistiocytosis (HLH) is a devastating disorder with protean clinical manifestations caused by the overproduction of T-cell derived cytokines. Cytokine-dependent activation of the Janus family kinases (JAK) is a hallmark of the final common pathway in HLH pathogenesis. Therefore, we initiated a single center, open-label, investigator-initiated trial to assess the efficacy and safety of ruxolitinib in adult patients with secondary HLH. Methods: Adult patients (≥18 years) who fulfilled 5 of 8 diagnostic criteria were eligible. Patients with CNS involvement or an active malignancy were ineligible. Patients who had received any prior systemic therapy (excluding corticosteroids) within 7 days of treatment were ineligible. Patients with normal renal function received oral ruxolitinib 15 mg twice daily on a continuous, 28-day cycle. Dose reductions for renal insufficiency and toxicity are permitted. Treatment was continued indefinitely until disease progression, unacceptable toxicity, or any other conditions for treatment discontinuation were met. The first patient was enrolled in February, 2016 and enrollment is ongoing. The primary endpoint is overall survival at 2 months. Secondary endpoints include the response rate, duration of response, progression-free and overall survival. Adverse events were graded and attributed in accordance with the National Cancer Institute Guidelines for the Cancer Therapy Evaluation Program. Disease parameters evaluable for response included all quantifiable signs and laboratory abnormalities included in the diagnostic criteria for HLH. A complete response (CR) required normalization of all signs and laboratory abnormalities. At least 25% improvement in two or more signs/laboratory abnormalities was required for a partial response (PR). At least a 50% worsening in two or more signs/laboratory abnormalities was considered progressive disease (PD), while failure to fulfill any of these criteria was considered stable disease (SD). Results: A total of 4 patient have been enrolled, all of whom fulfilled at least 5 of 8 diagnostic criteria for HLH. Hemophagocytosis, a pathologic hallmark of HLH, was observed in every patient. At the time of treatment initiation, all patients were anemic [median hemoglobin 7.1 g/dL (range: 6.2-7.5 g/dL)] and thrombocytopenic [median platelet count 47 K/uL (range: 14-107 K/uL)]. Three patients were neutropenic [median ANC 0.95 K/uL (range: 0-1.9 K/uL)]. HLH was secondary to an autoimmune disorder (n=3), infection (n=1), and a homozygous mutation in the STXBP2 gene, recently identified as a causative defect in primary HLH, was observed in one patient. Cytopenias significantly improved within the first week of treatment in all patients. On day +7, the mean increase in hemoglobin was 1.88 g/dL (0.2-3 g/dL), in ANC was 1.53 K/uL (range 0.1-5.3 K/uL) and platelet count was 74 K/uL (range 17-116 K/uL). Neutropenia resolved by day +40 and thrombocytopenia resolved by day +47 in all patients. Three of four patients became transfusion independent within 2 days of treatment initiation. Three of four patients received corticosteroids prior to and after initiation of ruxolitinib. The mean corticosteroid (prednisone equivalent) dose prior to treatment initiation was 225 mg/day (range: 60-391 mg/day) and was 38 mg/day (range: 0-75 mg/day) on day +30. Within 47 days of treatment initiation, corticosteroids were discontinued in 2 patients, and were discontinued in all patients by day +54. Significant improvements in ferritin and sIL-2R were also observed with a median 92.6% decrease in ferritin by day +30 (range 86.4-92.6%) and 86% median decrease in sIL-2R by day +30 (range 66.6-92.7%). All patients achieved at least a PR, and 2 patients remain on treatment (>2 months, >8 months). Two patients discontinued treatment, one for progressive disease (due to recurrent symptoms), and another for drug intolerance (neuropathic foot pain). No severe adverse events have been observed. In addition to the patients enrolled in this study, two additional patients who met eligibility criteria were similarly treated (off study) at another institution. Both of these patients achieved at least a PR and remain on treatment (>8 months, >14 months). Conclusions: Ruxolitinib led to rapid and durable responses and was well tolerated in adult patients with secondary HLH. Disclosures Devata: Affimed: Research Funding. Phillips:Abbvie: Research Funding; Pharmacyclics: Consultancy, Research Funding; Genentech: Consultancy; Bayer: Consultancy; Seattle Genetics: Consultancy; Gilead: Consultancy. Sood:Bayer: Research Funding. Wilcox:Incyte, Corp: Research Funding.

Background AFM13 is a bispecific, tetravalent NK cell-engaging antibody construct binding to CD30 on CD30+ tumor cells and CD16A on NK cells. By engaging CD16A-positive NK cells, AFM13 leads to NK cell-mediated killing of CD30-positive lymphoma cells (Reusch et al., 2014) making it an attractive agent to target classical Hodgkin lymphoma (HL). Pembrolizumab is a PD-1 blocking antibody which has shown high single-agent response rates in patients (pts) with relapsed/refractory HL (RRHL; Armand et al., 2016, Chen et al., 2017). AFM13 has shown clinical activity in RRHL as a single agent in a preceding Phase 1 study (Rothe et al., 2015). Preclinical in vivo data of the combination of AFM13 with PD-1 blockade showed synergistic activity and the potential for induction of cross-talk between innate and adaptive immunity (Zhao et al., 2016). We hypothesize that the combination of the two agents could improve outcomes in pts with RRHL. Methods This Phase 1b study is evaluating the safety and tolerability of the combination of AFM13 with pembrolizumab (Keytruda) as salvage therapy after failure of standard therapies including brentuximab vedotin (BV) in HL (NCT02665650). Pts receive escalating doses of AFM13 in combination with pembrolizumab at a dose of 200 mg flat administered every 3 weeks following a classical 3+3 design, followed by enrollment into an extension cohort at the maximum tolerated dose (MTD)/maximum administered dose (MAD). Response assessment is performed every 12 weeks by PET/CT according to the Lugano Classification (Cheson et al., 2014). The main objectives of the study is to ascertain the MTD/MAD along with the preliminary efficacy of the combination. Results As of June 29, 2018, 30 pts have been enrolled into the study. The median age is 34 years (range, 18-73), with a median of 4 (range 3-7) prior lines of therapy. All pts had relapsed or refractory disease (43% relapsed, 57% refractory) and had failed standard treatments including BV and 43% of pts (13/30) had BV as their latest therapy. Thirty seven percent (11/30) had undergone prior autologous stem cell transplantation. All 30 pts have completed the 6-week dose-limiting toxicity (DLT) observation period. Twelve pts were enrolled into the dose escalation cohorts (Cohorts 1 (n=3), 2 (n=3), and 3 (n=6)) and 18 into the Extension Cohort, with a total of 24 patients treated at the MAD (dose level 3). One DLT was observed in Cohort 3 (missing ≥25% of AFM13 during the DLT period) and another observed in the Extension Cohort (G4 infusion-related reaction; IRR). The most common related adverse events (AEs) were IRRs (80%), rash (30%), pyrexia (23%), nausea (23%), diarrhea (20%), fatigue (17%), headache (17%), increased aspartate aminotransferase (13%), and increased alanine aminotransferase (10%). Treatment related G3/4 AEs included IRRs (13%), elevated AST (3%), gastritis (3%), hypotension (3%), nausea (3%), neutropenia (3%), and vomiting (3%). The majority of IRRs were manageable with standard of care measures and did not lead to treatment discontinuations. Included in the efficacy analysis were the best response from 29 evaluable pts who had at least one post-baseline disease assessment as of the data cutoff on June 29, 2018. The overall response rate (ORR) and complete response (CR) rate for evaluable pts treated at the dose and schedule chosen for expansion (n=23; Cohort 3 and Extension Cohort) were 87% and 35% by the investigator-confirmed assessment, respectively. Independent assessment resulted in an ORR of 87% and CR rate of 39% for these pts. Updated data for all 30 patients will be presented at the meeting. Conclusions The combination of AFM13 and pembrolizumab is a well-tolerated salvage therapy in pts with RRHL. IRRs were the most frequently observed adverse events; however, most of these events were of mild or moderate severity and manageable. Both the ORR and CR rate compare favorably to monotherapy pembrolizumab in a similar RRHL population (Chen et al., 2017). The combination of AFM13 and pembrolizumab could be a potential new therapeutic option for HL patients. Disclosures Bartlett: Immune Design: Research Funding; Affimed: Research Funding; Bristol-Meyers Squibb: Research Funding; Merck & Co: Research Funding; Pharmacyclics: Research Funding; Celgene: Research Funding; Pharmacyclics: Research Funding; Genentech: Research Funding; Forty Seven: Research Funding; Novartis: Research Funding; Novartis: Research Funding; Millennium: Research Funding; ImaginAB: Research Funding; Pfizer: 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, Research Funding; Janssen: Research Funding; KITE: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Seattle Genetics: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Astra Zeneca: Research Funding; Acerta: Membership on an entity's Board of Directors or advisory committees. Chen:Affimed: Research Funding; Bristol-Myers Squibb: Consultancy, Research Funding; Genentech Inc.: Consultancy; Seattle Genetics: Consultancy, Honoraria, Research Funding, Speakers Bureau; Merck & Co., Inc.: Consultancy, Research Funding, Speakers Bureau; Millennium Pharmaceuticals: Consultancy, Research Funding; Pharmacyclics: Consultancy, Research Funding. Domingo-Domenech:Affimed: Research Funding. Forero-Torres:Affimed: Research Funding. Garcia-Sanz:Affimed: Research Funding. Devata:Affimed: Research Funding. Rodriguez Izquierdo:Affimed: Research Funding. Lossos:Affimed: Research Funding. Reeder:Affimed: Research Funding. Sher:Affimed: Research Funding. Choe-Juliak:Affimed: Employment. Prier:Affimed: Research Funding. Schwarz:Affimed: Employment. Strassz:Affimed: Employment. Alland:Affimed: Employment. Ansell:Bristol-Myers Squibb: Research Funding; Celldex: Research Funding; LAM Therapeutics: Research Funding; Trillium: Research Funding; Pfizer: Research Funding; Regeneron: Research Funding; Seattle Genetics: Research Funding; Merck & Co: Research Funding; Affimed: Research Funding; Takeda: Research Funding.

Introduction Tenalisib (RP6530) is a next generation, oral, selective, PI3Kδ/g inhibitor with nanomolar inhibitory potency. Besides its apoptotic and anti-proliferative activity, Tenalisib modulates the tumor microenvironment resulting in reprogramming of tumor associated-macrophages (TAMs) from a protumor M2 phenotype to an antitumor M1 phenotype and a marked reduction of angiogenesis in pre-clinical models. Tenalisib has demonstrated activity in patients with relapsed/refractory lymphoid malignancies (Carmelo, ASH 2016 and Oki, ASCO 2018). Since there are concerns over long-term safety of PI3K δ or PI3K dual δ/g inhibitors with respect to immune-mediated toxicities (e.g. transaminitis, colitis and pneumonitis), cytopenias, and infections, a pooled safety analysis across two Phase I studies in patients treated with Tenalisib was performed. Methods Safety data was pooled from two Phase I Tenalisib monotherapy trials (NCT02017613 and NCT02567656) with similar key eligibility criteria. Patients had R/R lymphoid malignancies with ≥1 prior therapy. Responses were evaluated in lymphoid malignancies using IWG criteria (Cheson et al., 2007) and in CTCL using the modified Severity Weighted Assessment Tool (mSWAT). Adverse events were graded according to CTCAE v4.03. Results A total of 93 patients were included in the analysis. Among these patients, 34% were PTCL, 32% CTCL, 16% HL, 6% DLBCL and 12% were other lymphomas. Patients received a median of 5 prior therapies. 53 % of patients received Tenalisib for ≤ 3 months, 21% for 3-6 months and 26% for > 6 months. The overall incidence of related AEs and ≥G3 AEs were 58% and 29% respectively (Table 1). Very few AEs were seen with exposures >6 months and mainly included single cases of diarrhea, anemia, edema, and abdominal pain. There were no incidences of late onset toxicities such as colitis and pneumonitis and most of the AEs happened during the initial three months of therapy. No treatment discontinuations due to AE's were seen in patients exposed to > 6 months of treatment. Efficacy response assessments of the 66 evaluable patients demonstrated an ORR of 45% in TCL (44% in PTCL (8/18, 3 CR, 4 PR) & 45% in CTCL (9/20, 9 PR)), 29% (4/14; 1CR; 3PR) in HL, and 13% (1/6; 1CR) in DLBCL. Conclusion In this pooled safety analysis with long term follow-up, Tenalisib exhibited an improved safety profile when compared to other investigational/marketed PI3K inhibitors. The incidence of transaminitis was low and occurred within the first two to three cycles of therapy. In particular, there were no occurrences of pneumonitis or colitis in patients that had been on treatment for > 3 months and beyond. Incidence of neutropenia/thrombocytopenia and infections was limited. Tenalisib can therefore be safely combined with a diverse array of other agents active in lymphoid malignancies. Tenalisib is currently being studied in combination with Pembrolizumab and Romidepsin and as a monotherapy in a Phase II trial in indolent NHL. Disclosures Haverkos: Viracta Therapeutics: Membership on an entity's Board of Directors or advisory committees. Ramchandren:Pharmacyclics LLC an AbbVie Company: Consultancy, Research Funding; Seattle Genetics: Consultancy, Research Funding; Bristol-Myers Squibb: Consultancy; Merck: Research Funding; Janssen: Consultancy, Research Funding. Devata:Affimed: Research Funding. Routhu:Rhizen Pharmaceuticals SA: Employment. Barde:Rhizen Pharmaceuticals SA: Employment. Nair:Rhizen Pharmaceuticals SA: Employment. Carlo-Stella:Boehringher Ingelheim Italia: Consultancy; Sanofi: Consultancy; MSD Italia: Speakers Bureau; Rhizen Pharmaceuticals: Research Funding; AstraZeneca: Speakers Bureau; ADC Therapeutics: Research Funding, Speakers Bureau; Janssen: Speakers Bureau; Genenta Science: Speakers Bureau; Bristol-Myers Squibb: Speakers Bureau; Amgen: Speakers Bureau.

Pancreatic neuroendocrine tumors (PNETs) are relatively rare tumors that arise in the endocrine cells of the pancreas. Historically, somatostatin analogues have been used in this disease primarily for symptom control and, to a limited extent, disease stability. More recently, sunitinib and everolimus have been approved for advanced stage PNETs based on a survival benefit. However, both agents have a

7510Background: Tenalisib is a novel, next generation, highly specific, dual equi-potent PI3K δ/γ inhibitor. Early results demonstrated an acceptable safety profile with encouraging clinical activi...

TPS219 Background: Talimogene laherparepvec, a modified herpes virus agent, induces a response in 65% of injected melanoma tumors. The combination of talimogene laherparepvec with ipilimumab or pembrolizumab appears promising in clinical trials of advanced melanoma. Talimogene laherparepvec-based therapy may be effective in other cancers of the skin and lymph nodes that are anatomically accessible for intratumoral injection. Methods: This phase II study will evaluate intratumoral talimogene laherparepvec monotherapy in 4 parallel disease cohorts: 1) Refractory T cell and NK cell lymphomas including cutaneous T cell lymphoma, 2) Merkel cell carcinoma 3) Cutaneous squamous cell carcinoma and 4) Other advanced/refractory non-melanoma skin cancers. Lymphoma patients must be refractory to or intolerant of all standard life-prolonging therapies. Skin cancer patients must be advanced/unresectable or refractory to one or more treatments including surgery, radiation therapy, or medical therapy. Prior PD-1-directed therapy is allowed. If an objective response is not achieved by Week 12, the PD-1 blocking antibody nivolumab will be added. The primary endpoint is the response rate with talimogene laherparepvec and secondary endpoints include response rate with the combination and overall survival. Using a two-stage design, if 1 or more response is observed in the first 9 patients in each parallel cohort, 8 additional patients will be accrued for a total sample size of 36 to 68 patients across the 4 disease cohorts. Tumor biopsies of injected lesions are mandatory at baseline and Week 6, and optional at Week 16 and the time of progression. Optional biopsies of non-injected lesions (when applicable) at Week 6 and 16 will be analyzed to identify biomarkers of systemic immunity. Tumor tissue and/or blood will be assayed for PD-L1 expression, RNA profiling, immune cell profiling, HVEM, NECTIN 1/2, IDO, tryptophan and L-kynurenine, mutational load, TIL TCR clonality, and prior exposure to herpes simplex type 1 virus and Merkel cell polyomavirus. Clinical trial information: NCT02978625.

Introduction: Follicular lymphoma (FL) constitutes the second most common non-Hodgkin's lymphoma in the Western world. Recently, novel mutations in the Bruton's Tyrosine Kinase (BTK) have been identified in FL (Krysiak et al, Blood 2017). Additional mutations in other components of BCR signaling pathways in FL have been reported as well but functional consequences have not been fully explored. Methods: Using a combination of WES on N=82 FLand BTK resequencing in an extended FL panel we uncovered novel BTK mutations in FL. These BTK mutations are all distinct from the previously identified mutations suggesting that a full complement of BTK mutations has not yet been identified. Using crispr-Cas9-mediated BTK gene targeting in multiple lymphoma cell lines, we generated novel BTK-/- null lines. We introduced all BTK mutations by site-directed mutagenesis into a reference BTK cDNA. Subsequently, we re-introduced HA-tagged wild type and mutated BTK constructs using lentiviral transduction into the BTK-/- cell lines and also into BTK-/- DT40 cells. We measured signal transduction pathway components following BCR cross linking. The location of BTK mutations was modeled onto a 3D-model assembled from various published BTK substructures. Results: Mutations in BTK are distributed along the entire length of the gene and are targeting the PH-, SH2- and catalytic domain, with the catalytic domain carrying the majority of BTK mutations. Interestingly, occasional frame shift mutations as reported and a splice acceptor site mutation by genetic criteria suggest gene inactivation. The 3D modeling data show that all BTK mutations are on the surface of the BTK protein within the various functional domains. The quantitation of BTK protein after reconstitution into various engineered BTK-/- cell lines uncovered lower steady state levels of various mutants especially for mutations targeting the catalytic domain. PLCγ2 remains the best studied BTK substrate and various sites have been reported to be phosphorylated by BTK in vivo (PLCγ2 amino acids 753, 759 and 1217). Following BCR crosslinking in engineered BTK-/- lymphoma cell lines we found only a modest reduction in the phosphorylation of PLCγ2 residue 759 or 1217 demonstrating that these sites are under the control of various tyrosine kinases and not exclusively targeted by BTK. After BCR crosslinking in the BTK-/- cells lines we detected a substantial increase in PLCy2 residues 759 or 1217 phosphorylation over baseline and this increase was abolished by ibrutinib pre-treatment. Therefore, PLCγ2 residue 759 or 1217 phosphorylation is due to multiple BCR stimulated and ibrutinib sensitive tyrosine kinases. In engineered BTK-/- lymphoma cell lines reconstituted with HA-tagged wild type and mutated BTK we did not detect major effects by the BTK mutants on the phosphorylation state of PLCγ2 residue 759 or 1217. In addition, phosphorylation of BTK at residue 223 (a major autophosphorylation site) was reduced or absent in multiple BTK mutants. Summarizing these findings, FL-associated BTK mutations do not activate the BTK kinase; instead, multiple BTK mutants are inactivating. Focusing on BCR-regulated signaling pathways, we measured ERK and AKT phosphorylation in the engineered BTK-/- lymphoma cell lines reconstituted with HA-tagged wild type and mutated BTK. Following BCR crosslinking, we detected increased p-AKT-473 phosphorylation in most BTK mutants in a total of 4 separate cell lines. In contrast, p-ERK was largely unaffected. Recent reports implicated AKT activation as a major factor in tonic BCR signaling in germinal center type DLBCL. We did not detect elevated AKT phosphorylation prior to BCR stimulation in our BTK reconstituted cell systems but an exaggerated response following BCR engagement. The effects of BTK mutations on protein-protein interactions within the BTK signalosome as well as effects on sensitivity to ibrutinib will be updated at the meeting. Conclusion : Our initial efforts at functional characterization of FL-associated BTK mutations uncovered that despite reduced stability and impaired catalytic activity most BTK mutations resulted in enhanced AKT activation following BCR crosslinking. Given the established pro-growth and pro-survival function of AKT, the data provide a clear reason why FL would select for such mutations. Disclosures Phillips: Incyte: Other: Travel/Expenses; Pharmacyclics: Consultancy; KITE: Consultancy; Seattle Genetics: Consultancy. Malek: Abbvie: Equity Ownership; Janssen R&D: Honoraria, Research Funding; Pharmacyclics: Honoraria, Research Funding.

e23169 Background: Personalized therapy through the identification of targetable mutations within individual tumors has increasingly become a focus in the management of patients (pts) with relapsed/refractory malignancy. To better understand how this is clinically applied, we reviewed 29 cases of B- and T-cell lymphomas that had genetic sequencing of their tumor. Methods: The electronic medical records of 29 pts who underwent Michigan Oncology Sequencing (MI-ONCOSEQ) testing at the University of Michigan from 2013-2016 were reviewed for disease and treatment history. Reports from whole-genome tumor sequencing were obtained for each patient to identify putative molecular targets. Results: Sixteen male and 13 female pts had a median age of 59 years (range 30-80 years) and median disease stage of IV at diagnosis. Five had CTCL, 5 PTCL, 11 follicular, 1 CLL/ mantle cell (MC), 1 MC, 1 marginal zone, 1 Waldenstrom’s (WM) and 4 DLBCL. Pts received a median of 2 therapies prior to MI-ONCOSEQ biopsy. Targetable mutations were identified in 15 pts and a total of 5 pts underwent MI-ONCOSEQ-based treatments. Bosutinib was given for FYB-FGR fusion, imatinib for FLI1-PDGFRB fusion, and everolimus for activating mTOR mutation with an avg. treatment duration of 3.6 weeks due to progressive disease. Bosutinib and imatinib were 3rd line therapies and everolimus was 5th. Another 2 pts were treated with ibrutinib for transformed WM with MYD88 mutation and bortezomib after classification of DLBCL as ABC-type based on MI-ONCOSEQ results, with CR in both. Other targetable mutations identified include BRAF, CDK, BCL2, EZH2 and NOTCH. Of the remaining 12 pts with targetable mutations, 8 pursued clinical trials, 2 responded to standard therapy, 1 died shortly after genetic analysis and 1 declined further therapy. About 50% of these pts remain alive. Conclusions: Our results demonstrate that targeted therapy is favored after standard therapy or clinical trial options are exhausted. Barriers to its use include the availability of clinical trials, off-label drug access and our incomplete knowledge of driver mutations. With further understanding of disease pathogenesis, we expect personalized therapy will be possible for all patients.

Background : Selectins, among other adhesion-mediated functions, facilitate and augment thrombosis; standard anticoagulants address thrombosis but also increase bleeding risk. Previous work in animal models showed inhibiting E-selectin decreases venous thrombosis (VTE) and vein wall inflammation without adverse bleeding events, making E-selectin inhibition a favorable therapeutic candidate for VTE. GMI-1271 is a potent, specific E-selectin antagonist. Here we report final analysis of safety, PK, biomarker and bleeding risk profile for GMI-1271 in 2 phase 1 studies of healthy subjects. Methods: The first study was a blinded single ascending dose (SAD) evaluation of 2, 5, 20, or 40mg/kg of GMI-1271 (n=4/cohort), vs placebo control saline (n=4) or active control Lovenox 1mg/kg (n=4). The second was an open-label multiple ascending dose (MAD) study of 10 (n=3) or 20mg/kg (n=3) of GMI-1271 QD d 1-5 vs Lovenox 1mg/kg (n=2) d 1-5. Assessments included safety (adverse events [AEs], clinical labs, bleeding time, PT/PTT, vitals, exam); PK (plasma and urine); and biomarkers. Biomarkers included ELISAs (CRP, D-dimer, IL-10, MPO, Prothrombin fragment 1.2, soluble E-selectin (sEsel), soluble P-selectin (sPsel), sICAM, Thrombin-antithrombin complex (TAT), Tissue Factor (TF), TNFα, VWF activity, and sCD40L); PicoGreen Assay for circulating DNA; flow cytometry (Platelet Monocyte Aggregates (PMA), Mac-1, LFA-1, and CD44) and Thromboelastography (TEG). See Table 1 for functional description. SAD remains blinded to GMI-1271 or placebo (GMI-1271/p). In SAD, we measured biomarker values at baseline, 8 and 24 h after dosing. Analysis was performed of biomarkers at each dose level and then pooled by GMI-1271/p vs Lovenox. In MAD, we measured biomarker values at baseline and day 4. Comparisons were made using unpaired t-test. Results: In total, 32 subjects enrolled and received GMI-1271/placebo (GMI-1271/p; 20), GMI-1271 (6) or Lovenox (L; 6). Safety: All subjects completed dosing uneventfully. Safety findings for GMI-1271/p were unremarkable. No moderate or serious AE were seen. AE overall were as expected in healthy volunteers. In SAD, only 1/20 GMI-1271/p subjects experienced an AE possibly related to study drug (mild transient headache); 0/6 in MAD. In the L group we saw expected mild transaminitis and injection site bruising. In all studies, GMI-1271 had no effect on bleeding time, PT, or PTT. PK: Plasma levels, Cmax, and AUC increased in a linear manner. Cl, Vz, and t ½ were not dose dependent; no accumulation was seen with multiple dosing (Fig 1 and 2). TEG: In SAD, there was a tendency to increase R, K, and decrease A and MA with no change in % lysis in L vs GMI-1271/p. In MAD, we saw a similar trend as SAD except for an increase in % lysis in L. In the pooled SAD analysis, there was a statistically significant difference between GMI-1271/p and L (higher values) for R (p sEsel: In SAD, there was a trend for sEsel to decrease with treatment in all cohorts (combined GMI-1271/p vs L p= 0.017). In MAD, there was non-significant trend for sEsel to decrease between Day 0 and Day 4 in GMI-1271; sEsel levels trended upward with L in comparison. MPO: In SAD, there was a trend for increased values in L vs GMI-1271/p, except for the 40mg/kg cohort. When pooled, there was a significant difference between GMI-1271/p vs L (higher levels) p MAC-1 In SAD, there was no change. In MAD, there was a significant decrease in MAC-1 at the 10mg/kg dose (p No other notable trend was seen in the other biomarkers measured. Conclusion: We report a favorable safety, biomarker and bleeding profile for the E-selectin antagonist GMI-1271 in healthy subjects. There is no signal to suggest GMI-1271 increases bleeding potential based on adverse events, PT, PTT, bleeding time, and TEG values, unlike traditional anticoagulants. An additional unblinded analysis of the biomarkers will be presented at ASH. We note a trend for sE-sel to decrease with GMI-1271 treatment even in this healthy volunteer population, consistent with previous experience and as expected based on mechanism of action. A phase 1 study of GMI-1271 is currently ongoing to evaluate the safety and efficacy of E-selectin antagonism for the treatment of patients with calf vein DVT. PK Figures: Figure 1: SAD; Figure 2: MAD. Figure 1 Figure 1. Figure 2 Figure 2. Disclosures Hemmer: GlycoMimetics, Inc.: Employment, Equity Ownership. Flanner:GlycoMimetics, Inc.: Employment. Parker:GlycoMimetics, Inc.: Employment. Li:GlycoMimetics, Inc.: Employment, Equity Ownership. Froehlich:Novartis: Consultancy; Janssen: Consultancy; Pfizer: Membership on an entity's Board of Directors or advisory committees; Boehringer-Ingelheim: Membership on an entity's Board of Directors or advisory committees; Fibromuscular Disease Society of America: Research Funding; Blue Cross/Blue Shield of Michigan: Research Funding; Merck: Consultancy. Magnani:GlycoMimetics: Employment, Equity Ownership, Membership on an entity's Board of Directors or advisory committees. Thackray:GlycoMimetics: Employment, Equity Ownership. Sood:Bayer: Research Funding.

Background: Resistance to conventional anthracycline-based regimens (CHOP/CHOEP) and the emergence of primary refractory disease remains a clinical challenge in PTCL, and is observed in ≈25% of patients. Outcomes in the setting of primary refractory disease, particularly for those patients who fail to achieve a remission with second-line chemotherapy, are poorly described and the optimal therapeutic strategy for these patients remains uncertain. Patients and Methods: We identified 159 patients with PTCL who received multi-agent, anthracycline-based treatment from 1988 to 2011 in the PTCL database at our institution. Primary refractory disease, defined as disease progression during initial therapy or relapse within 6 months of its completion, was observed in 58 (36%) of patients. Results: The median age at diagnosis with primary refractory PTCL was 49 years (range, 18.8-77.1). Median follow up was 2.7 years among surviving patients (95% CI, 1.2-6.3). Median overall survival (OS) was 1.1 years (95% CI, 0.7-1.9). The median number of lines of therapy underwent by patients was 3 (range, 1-9). PTCL, NOS (n=24), angioimmunoblastic T-cell lymphoma (n=6), and ALK-positive anaplastic large cell lymphoma (n=7) accounted for the majority (63.8%) of these patients. No difference in OS was observed between patients who failed to respond to initial therapy and those who relapsed within 6 months after a first remission (median OS 0.9 [95% CI, 0.6-1.9] vs. 1.3 [95% CI, 0.5-6.3], p=0.6). After developing primary refractory disease, 48.3% of patients received aggressive, multi-agent salvage regimens (ICE, n=16; DHAP, n=3; ESHAP, n=6; other, n=3), 29.3% of patients received other systemic therapies (HDAC inhibitor, n=1; gemcitabine-based therapies, n=5; pralatrexate, n=3; other, n=8), and 22.4% of patients received no systemic therapies. Patients who received no systemic salvage therapy had reduced OS compared to both patients who received aggressive regimens and patients who received other types of systemic therapies (median OS 0.3 [95% CI, 0.2-1.1] vs. 1.7 [95% CI, 0.8-11.7] vs. 1.3 [95% CI, 0.4-8.6], respectively, p Conclusion: Primary refractory PTCL is associated with dismal outcomes. The likelihood of achieving a remission and proceeding to transplant is ≈30% and with transplant, only 11 (19% of patients with primary refractory disease) achieved a durable remission. Improved understanding of resistance mechanisms in PTCL and the development of improved therapeutic strategies are needed. A significant survival benefit was not observed for patients receiving traditional salvage regimens compared to other systemic second-line regimens, with median survival Disclosures No relevant conflicts of interest to declare.

Desmoid tumors are rare, clonal collections of benign fibrous tissue that exhibit a highly variable clinical course. This article presents a comprehensive review of desmoid tumors and summarizes the current literature pertaining to clinical presentation, diagnostic modalities, pathogenesis, prognostic factors, and management options.