Citations

Abstract Background: New targeted therapies continue to show improved efficacy in various stages of chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL), sparing patients from chemoimmunotherapy. However, cure remains elusive. Here, we present a front-line alternative based on a combination of high-dose methylprednisolone (HDMP) and ofatumumab, followed by consolidative therapy with lenalidomide plus ofatumumab. Methods: This is a phase II, single-center study in patients with treatment-naive (TN) CLL/SLL. During the first treatment phase (cycles 1-3) patients received HDMP 1000 mg/m2 IV and ofatumumab 2000 mg (300 mg given week 1 then 2000 mg for a total of 12 doses) IV infusions weekly x 4 doses in cycle 1 of a 28 day cycle, then every 2 weeks for cycles 2 and 3. During the second treatment phase (cycles 4-12), patients received renally adjusted lenalidomide 5-10 mg daily and ofatumumab 2000mg IV once every 8 weeks. Growth factor support was permitted at the discretion of treating physician. Prophylactic medications included allopurinol for tumor lysis syndrome (TLS) 3 days before C1D1 through C1; and trimethoprim/sulfamethoxazole and fluconazole through cycle 4, and acyclovir through C12. Patients received aspirin 81 mg/day as thrombosis prophylaxis while on lenalidomide. Patients were assessed for response by iwCLL 2008 criteria (including imaging assessment) after completion of cycles 3 and 12. The study allowed continuation of lenalidomide if patients achieved complete (CR), partial (PR) response or stable disease (SD). Primary endpoints were efficacy, adverse events (AEs) profile, and time-to-treatment failure (TTF). Results: Between January 2012 and September 2015, the study enrolled a total of 45 patients. Median follow-up was 50.4 (5.6-72.8) months. The median age was 62.6 (48.2-86.1) years. Chromosomal analysis by FISH demonstrated Del17p in 8 (17.8%), Del11q (+/- others, except Del17p) in 10 (22.2%), Trisomy 12 (+/- others, except Del17p and Del11q) in 8 (17.8%), Del13q in 10 (22.2%), no mutations in 9 (20%) patients. The IGHV status was unmutated in 34 (75.6%) cases. Indications to start treatment were: symptomatic lymphadenopathy, symptomatic splenomegaly, anemia, and thrombocytopenia in 5 (11.1%), 10 (22.2%), 12 (26.7%), and 18 (40%), respectively. The median duration of treatment was 35.6 (2.7-66.9) months. Reasons for treatment discontinuation were: progressive disease (PD) in 9 (20%), AEs in 15 (33.3%), transplantation in 3 (6.7%), consent withdrawal in 1 (2.2%), and secondary malignancies in 2 (4.4%) cases. The overall response rates (PR+CR) at 3, 12, 24, 36, and 48 months were 75.6%, 77.8%, 66.7%, 44.4%, and 37.8%, respectively. The CR rates at 3, 12, 24, 36, and 48 months were 2.2%, 11.1%, 20%, 17.8%, and 13.3% respectively. Fifteen patients remain in PR/CR and on treatment at the time of this analysis. The intention-to-treat median TTF was 45.2 (2.9-69.7) months, and was not different among high risk groups such as Del17p, Del11q and/or unmutated IgHV. In patients who discontinued for reasons other than PD the median duration of response without treatment was 30.7 (9.8-69.7) months. Three (6.7%) patients underwent allogeneic hematopoietic cell transplantation after a median of 3 (3 - 4) treatment cycles. Treatment was well tolerated with grade 3/4 infusion reaction in 1 (2.2%) patient. Grade 3/4 treatment-related hematological AEs were neutropenia, thrombocytopenia, and anemia in 33 (73.3%), 5 (11.1%), and 1 (2.2%), respectively. Grade 3/4 infections occurred in 6 (13.3%) patients. No grade 3/4 tumor flares were observed, and there were no cases of TLS or thrombosis. Conclusion: The combination of ofatumumab, HDMP and lenalidomide is effective and well tolerated in treatment-naive CLL/SLL, even when poor prognostic features are present. Disclosures Komrokji: Novartis: Honoraria, Speakers Bureau; Novartis: Honoraria, Speakers Bureau; Celgene: Honoraria, Research Funding; Novartis: Honoraria, Speakers Bureau; Celgene: Honoraria, Research Funding; Novartis: Honoraria, Speakers Bureau. Locke:Novartis Pharmaceuticals: Other: Scientific Advisor; Cellular BioMedicine Group Inc.: Consultancy; Kite Pharma: Other: Scientific Advisor. Kharfan-Dabaja:Seattle Genetics: Speakers Bureau; Incyte Corp: Speakers Bureau; Alexion Pharmaceuticals: Speakers Bureau. Sokol:Spectrum Pharmaceuticals: Consultancy; Seattle Genetics: Consultancy; Mallinckrodt Pharmaceuticals: Consultancy.

Abstract Background Melphalan, prednisone and thalidomide (MPT) is a standard therapy for NDMM recognized worldwide based on a statistically significant advantage in overall survival (OS) and progression-free survival (PFS) vs. MP (Facon Lancet 2007; Fayers Blood 2011; NCCN 2013). The combination of lenalidomide and low-dose dexamethasone (Rd) increased OS with fewer adverse events (AEs) than treatment with lenalidomide and high-dose dexamethasone in NDMM pts (ECOG E4A03) (Rajkumar Lancet Oncol 2010). The FIRST trial is a multicenter, open-label, phase III trial comparing the efficacy and safety of Rd versus MPT in transplant-ineligible NDMM pts. Methods NDMM pts either ≥ 65 years of age, or not candidates for SCT were randomized to one of three arms: Rd in 28-day cycles until disease progression (Arm A), Rd in 28-day cycles for 72 weeks (18 cycles, Arm B), or MPT in 42-day cycles for 72 weeks (12 cycles, Arm C). Assessments by International Myeloma Working Group criteria were done after each cycle. Pts with renal impairment were enrolled; however, pts on dialysis were excluded. Starting doses of lenalidomide and dexamethasone were adjusted based on renal function and age, respectively. Melphalan starting dose was adjusted based on age, absolute neutrophil count, platelet count, and renal function; and thalidomide was adjusted for age. Dose adjustments were permitted for AEs. All pts were required to receive anti-thrombotic prophylaxis. Stratification factors included age, International Stage System, and country. The primary endpoint was a comparison of PFS in Arm A vs. Arm C. Secondary endpoints included OS, overall response rate (ORR), time to response, duration of response (DOR), safety, and quality of life (QOL). A preplanned additional analysis included time from randomization to second progression event or death (PFS2). The final preplanned analysis of independently adjudicated progressive disease (PD) events in Arm A vs. Arm C conducted after 960 events of death or PD, and an interim of OS in 64% of survival events (574/896 events) are presented in this abstract. Comparisons of PFS and all secondary endpoints, including OS for all three arms, will be presented at the meeting. Results A total of 1,623 pts were randomized 1:1:1 in three arms. As of today, 121 pts continue to receive lenalidomide on study (Arm A). The median age was 73 (40.0–92.0) years; 35% pts were aged ≥ 75 years; and 41% of pts had ISS stage 3 disease. After a median follow-up of 37 months, the trial met its primary endpoint (PFS), demonstrating a 28% reduction in risk of progression or death (HR=0.72; p= 0.00006). The preplanned interim analysis of OS demonstrated a 22% reduction in risk of death in favor of Arm A vs. Arm C (HR=0.78, p=0.01685); however, the pre-specified boundary (p<0.0096) was not crossed. All other secondary endpoints consistently showed improvement in favor of Arm A vs. Arm C; ORR (PR or better) 75% vs. 62% (p < 0.00001), DOR (HR=0.63; p<0.00001), and PFS2 (HR=0.78, p=0.0051). Relevant Grade 3/4 adverse events in Arm A vs. Arm C were neutropenia (28% vs. 45%), thrombocytopenia (8% vs. 11%), febrile neutropenia (1% vs. 3%), infection (29% vs. 17%), neuropathy (5% vs. 15%), and deep-vein thrombosis (5% vs. 3%). The incidence of secondary primary malignancies (SPM) was evaluated. Hematologic malignancies were 0.4% in Arm A vs. 2.2% in Arm C; the overall incidence of solid tumors was identical (2.8%). Conclusion Continuous treatment with the all oral doublet Rd significantly improved the primary endpoint of PFS compared with the standard triplet, MPT. All secondary endpoints support the clinical benefit of continuous Rd treatment. The safety profile of Rd was manageable, with reduced hematologic SPM compared to MPT. Disclosures: Facon: Celgene: Membership on an entity’s Board of Directors or advisory committees, Speakers Bureau. Off Label Use: Lenalidomide as treatment for NDMM. Dimopoulos:Celgene, Orthobiotech: Honoraria. Dispenzieri:Celgene, Millenium, Jansenn, Pfizer: Research Funding. Catalano:Celgene, Roche: Honoraria, Membership on an entity’s Board of Directors or advisory committees, Research Funding. Hulin:Janssen: Honoraria; Celgene: Honoraria. Cavo:Celgene, Janssen, Millennium, Onyx, Brystol Myers Squibb: Consultancy, Honoraria, Membership on an entity’s Board of Directors or advisory committees. Pinto:Mundipharma: Consultancy, Honoraria; Roche: Honoraria; Celgene: Consultancy, Honoraria. Weisel:Janssen: Consultancy, Honoraria; Celgene: Consultancy, Honoraria, Research Funding. Ludwig:Celgene: Honoraria, Research Funding, Speakers Bureau. Bahlis:Celgene: Consultancy, Honoraria. Delforge:Celgene: Honoraria. Chen:Celgene: Consultancy, Research Funding; Lundbeck: Consultancy; Johnson & Johnson: Consultancy, Research Funding; Roche: Honoraria; GlaxoSmithKline: Research Funding. Oriol:Celgen: Consultancy. White:Celgene: Honoraria, Research Funding. Binder:Celgene: Research Funding. Anderson:Acetylon, OncoPep: Equity Ownership; Celgene, Onyx, Sanofi Aventis, Gileod: Consultancy. Moreau:Celgene Corporation: Honoraria, Speakers Bureau. Attal:Janssen: Lectures, Lectures Other, Membership on an entity’s Board of Directors or advisory committees; Celgene Corporation: Lectures Other, Membership on an entity’s Board of Directors or advisory committees. Knight:Celgene: Employment, Equity Ownership. Chen:Celgene: Employment. Van Oostendorp:Celgene: Employment. Jacques:Celgene: Employment. Ervin-Haynes:Celgene: Employment, Patents & Royalties. Benboubker:Celgene: Consultancy.

Abstract Abstract 769 Despite the many and diverse therapeutic approaches used to treat patients with mantle cell lymphoma (MCL), it remains an incurable disease. Recently, attention has turned into novel therapies targeting MCL-specific oncogenic pathways important for the growth and maintenance of the transformed phenotype. The chromosomal translocation t(11;14)(q13;q32) leading to cyclin-D1 over-expression is the hallmark of MCL. Constitute cyclin-D1 activation in B-lymphocytes maintains retinoblastoma protein in a phosphorylated state and promotes cell cycling, thus initiating the tumorigenesis process. Cyclin-D1 has been postulated as a putative target for therapeutic intervention, however its evaluation has been hampered by the incomplete understanding of the mechanism underlying this cyclin oncogenic function and by the lack of valid MCL models. To investigate these issues, we developed a combined cellular-genomics screening whereby responses to known cytotoxic compounds targeting cancer-related molecular pathways were correlated with genomic, gene expression and proteomic profiles of human MCL cells. Results showed that cyclin-D1 silencing had minimal antitumoral effects but significantly increased the therapeutic efficacy of several compounds, especially the BH3 mimetics that inhibited anti-apoptotic protein BCL-2. To further evaluate this finding we generated a MCL mouse model by transducing a tetracycline-regulatable cyclin-D1-expressing vector in murine pro-B cells, which allowed modulating cyclin-D1 expression levels. These mice generated lymphomas recapitulating most of the cellular, histopathological and molecular features of human MCL. Similar to the previous in vitro findings, cyclin-D1 inhibition in this model did not induce lymphoma regression, but sensitized cells to apoptosis. Analysis of the mechanisms underlying this therapeutic synergy identified a novel role for cyclin-D1 as a pro-survival molecule. Specifically, cyclin-D1 sequestrated the pro-apoptotic effector protein BAX in MCL cells, thereby favoring BCL2 anti-apoptotic function. Accordingly, therapeutic cyclin-D1 inactivation released BAX, thus sensitizing cells to apoptosis and inducing lymphoma regression. Interestingly, pharmacological blockade in vivo of cyclin-D1 with Roscovitine synergistically cooperated with the BH3 mimetic ABT-737 to effectively inhibit MCL tumor growth. In summary, our study reveals a novel role for cyclin-D1 in deregulating apoptosis in MCL cells and highlights the potential benefit of cyclin-D1 targeting, thus providing the rationale for the clinical evaluation of drugs targeting cell proliferation and survival pathways in MCL. Disclosures: Siebert: Abbott: Honoraria.

Abstract Introduction Ibrutinib has become a new standard of care in patients with previously treated CLL/SLL based on the phase 3 RESONATE study (Byrd, et al. NEJM 2014) and other trials evaluating ibrutinib mainly as a single agent in CLL. The first randomized, double-blind, placebo-controlled phase 3 study (HELIOS) investigating ibrutinib in combination with bendamustine and rituximab (BR) was recently reported (Chanan-Khan, et al. ASCO 2015), with ibrutinib significantly extending progression-free survival and reducing the risk of progression/death by 80%. The study design provides an opportunity to examine the overall safety and management of adverse events (AEs) with ibrutinib and placebo in a blinded manner that previously has not been possible. Here we examine the safety and management of AEs with ibrutinib + BR vs placebo + BR in HELIOS. Methods Patients with active CLL/SLL following ≥ 1 prior line of systemic therapy were randomized 1:1 to receive BR (≤ 6 cycles) with either ibrutinib 420 mg daily or placebo (n = 289 in each group). Safety was a secondary end point. Results Median exposure to ibrutinib and placebo was 14.7 and 12.8 months, respectively. Rates of infection in the ibrutinib + BR and placebo + BR arms were similar (all-grade, 70.4%; grade ≥ 3, 26.8% vs all-grade, 70.0%; grade ≥ 3, 22.6%, respectively) but exposure-adjusted analysis reveals an overall lower rate of infections with ibrutinib + BR vs placebo + BR (10.3/100 vs 11.2/100 patient-months), with similar rates of grade ≥ 3 infections (2.4/100 patient-months each arm). Rates of all-grade (grade 3/4) anemia were 22.3% (3.5%) with ibrutinib + BR and 28.9% (8.0%) with placebo + BR. Patients also required fewer transfusions with ibrutinib + BR (23%) vs placebo + BR (29%), the majority of which were red blood cell transfusions. Similar proportions of patients used growth factors in both arms (54% vs 52%, respectively). Grade 3/4 neutropenia was reported at similar rates in both arms (53.7% vs 50.5%, respectively); however, fewer patients discontinued due to treatment-related neutropenia with ibrutinib + BR (1.0%) vs placebo + BR (2.8%). Rates of thrombocytopenia were slightly higher with ibrutinib + BR (30.7%) than placebo + BR (24.0%), but rates of grade 3/4 events were similar between arms (15.0% each arm). Atrial fibrillation (AF) was observed more frequently in patients on ibrutinib + BR than placebo + BR (7.3% vs 2.8% overall and 2.8% vs 0.7% grade 3/4, respectively). However, only 4 patients with grade 3/4 AF discontinued therapy in the ibrutinib arm. No patients with grade 1/2 AF discontinued treatment. One-third of patients held ibrutinib treatment to manage AF, with all restarting at the same dose (420 mg). Median (range) time to onset was 3.0 (0.3-17.5) months with ibrutinib + BR and 2.4 (0.6-18.9) months with placebo + BR. Importantly, in those with a prior history of AF or abnormal heart rhythm, only 7/25 receiving ibrutinib + BR and 2/22 receiving placebo + BR developed AF/atrial flutter on study. The rates of any-grade bleeding were 31.0% and 14.6%, respectively, with the majority being grade 1 (77.5% and 69.0%, respectively). Low rates of grade 3/4 major bleeding were observed in the ibrutinib + BR (2.1%) and placebo + BR (1.7%) arms. Many patients (41.8% ibrutinib + BR, 41.1% placebo + BR) were receiving concomitant anticoagulant/antiplatelet medication. A low rate of treatment-related lymphocytosis was observed in both arms (7.0% ibrutinib + BR, 5.9% placebo + BR). The majority of cases resolved within 2 weeks. Conclusions In this randomized, double-blind, placebo-controlled trial, the addition of ibrutinib to BR was well tolerated and did not significantly impact the safety profile of BR. In addition, ibrutinib was associated with reduced rates of anemia and transfusional support. Consistent with its known toxicity profile, patients in the ibrutinib + BR arm had higher rates of bleeding (mostly grade 1 or 2) and AF; however, few patients discontinued therapy as a result of these AEs. A prior history of AF or abnormal heart rhythm did not lead to recurrent episodes in the majority of cases. Taken together, the results from HELIOS establish the significant efficacy of ibrutinib and also the overall positive risk-benefit profile of ibrutinib + BR. Disclosures Cramer: Janssen: Other: Travel grant, Research Funding, Speakers Bureau; Hoffman LaRoche: Other: Travel grant, Research Funding, Speakers Bureau; Astellas: Other: Travel grant; Glaxo Smith Klein/Novartis: Research Funding; Gilead: Other: Travel grant, Research Funding; Mundipharma: Other: Travel grant. Demirkan:Celgene: Other: Travel reimbursement; Amgen: Consultancy. Fraser:Hoffman LaRoche: Consultancy, Honoraria; Janssen: Honoraria, Research Funding, Speakers Bureau; Celgene: Honoraria, Research Funding. Santucci Silva:Janssen: Other: Travel reimbursement, Research Funding; GSK: Research Funding; Celgene: Research Funding; Merck: Research Funding; Novartis: Other: Travel reimbursement; Hoffman LaRoche: Other: Travel reimbursement, Research Funding. Janssens:Roche: Consultancy, Speakers Bureau; Mundipharma: Speakers Bureau; Janssen: Consultancy. Goy:Allos, Biogen Idec, Celgene, Genentech, and Millennium. Gilead: Speakers Bureau; Celgene: Consultancy, Research Funding, Speakers Bureau. Mayer:Janssen: Research Funding. Dilhuydy:Roche: Honoraria, Other: Travel reimbursement; Janssen: Honoraria, Other: Travel reimbursement; Mundipharma: Honoraria. Bartlett:Medimmune: Research Funding; Novartis: Research Funding; Pfizer: Research Funding; Genentech: Research Funding; ImaginAB: Research Funding; Astra Zeneca: Research Funding; Pharmacyclics: Research Funding; Janssen: Research Funding; Gilead: Consultancy; Seattle Genetics: Consultancy, Research Funding; Millenium: Research Funding; Celgene: Research Funding. Rule:Roche: Consultancy, Other: Travel reimbursement; Gilead: Research Funding; Celgene: Consultancy, Other: Travel reimbursement; J&J: Consultancy, Other: Travel reimbursement, Research Funding. Sun:Janssen/J&J: Employment, Equity Ownership. Phelps:Janssen/J&J: Employment, Equity Ownership. Mahler:Janssen: Employment, Other: Travel reimbursement. Salman:Janssen/J&J: Employment, Equity Ownership. Howes:Janssen/J&J: Employment, Equity Ownership. Hallek:AbbVie: Honoraria, Other: Speakers Bureau and/or Advisory Boards, Research Funding; Roche: Honoraria, Other: Speakers Bureau and/or Advisory Boards, Research Funding; Gilead: Honoraria, Other: Speakers Bureau and/or Advisory Boards, Research Funding; Pharmacyclics: Honoraria, Other: Speakers Bureau and/or Advisory Boards, Research Funding; Celgene: Honoraria, Other: Speakers Bureau and/or Advisory Boards, Research Funding; Boehringher Ingelheim: Honoraria, Other: Speakers Bureau and/or Advisory Boards; Mundipharma: Honoraria, Other: Speakers Bureau and/or Advisory Boards, Research Funding; Janssen: Honoraria, Other: Speakers Bureau and/or Advisory Boards, Research Funding.

Abstract Introduction Recent results from the HELIOS phase 3 study in relapsed/refractory CLL/SLL demonstrated that the addition of ibrutinib to chemoimmunotherapy with bendamustine/rituximab (BR) leads to an 80% reduction in risk of progression or death compared with placebo + BR (Chanan-Khan et al. ASCO 2015). In addition to prolongation of progression-free survival (PFS; median not reached vs 13.3 months; hazard ratio: 0.203, 95% confidence interval: 0.150-0.276, p<0.0001), overall response rate (ORR) and rates of complete response (CR) or CR with incomplete marrow recovery (CRi) were significantly improved with ibrutinib + BR (ORR: 82.7% vs 67.8%; CR/CRi: 10.4% vs 2.8%). Here we report additional analyses on the quality of response with ibrutinib combined with BR. Methods In total, 578 patients (pts) with relapsed/refractory CLL/SLL requiring treatment were randomized 1:1 (289 per arm) to receive BR (≤ 6 cycles) with either ibrutinib (420 mg daily) or placebo. Purine analog refractoriness (yes vs no) and number of prior therapies (1 vs > 1) were stratification factors. Pts with deletion 17p (del17p; > 20% of cells) were excluded. All pts were required to have ≥ 1 abnormal lymph node (LN; defined as a measurable lesion > 1.5 cm). The primary end point was independent review committee (IRC)-assessed PFS. In this analysis, individual parameters of response (LN, spleen, overall radiology, absolute lymphocyte count [ALC], complete blood count [CBC], and bone marrow [BM]) were evaluated. Minimal residual disease (MRD) was assessed by flow cytometry using an 8-color panel (Rawstron AC, et al. Leukemia. 2007;21:956-964); MRD samples were collected at confirmation of suspected CR (bone marrow) and every 3 months thereafter (peripheral blood). Rate of MRD-negative response was defined as the proportion of pts who reached negative disease status (< 0.01%, ie, < 1 CLL cell/10,000 leukocytes) in any sample. Reported MRD rates are based on the intent-to-treat (ITT) population. Results The ORR assessed by the IRC was 82.7% with ibrutinib + BR vs 67.8% with placebo + BR (p < 0.0001), and was consistent with ORR reported by the treating physician (investigator assessed) (ORR: 86.2% vs 68.9%, p < 0.0001). However, rates of CR/CRi were higher by investigator assessment (21.4%, ibrutinib + BR vs 5.9%, placebo + BR) than IRC (10.4% vs 2.8%). The IRC employed an independent evaluation of radiological scans including stringent evaluation of LN and volumetric assessment of spleen size-the main reasons for the difference in CR/CRi rates between investigator and IRC assessment. At baseline, similar proportions of pts in each arm had bulky disease defined as LN > 5 cm (54%-58%) or abnormal spleen (~40%) as assessed by IRC. Complete resolution of previous CLL/SLL manifestations as assessed by the IRC was achieved more often in the ibrutinib + BR arm in comparison with placebo + BR for LN (34.6% vs 15.2%), spleen (56.7% vs 37.0%), overall radiology (21.1% vs 9.0%), and BM (19.7% vs 5.9%). Rates of normalization of ALC (> 90%) and CBC (> 70%) were high and similar in the 2 arms. MRD was assessed in 120 pts treated with ibrutinib + BR and 57 pts treated with placebo + BR and was negative in 37 pts and 14 pts, respectively, which corresponds with an MRD-negative response rate of 12.8% vs 4.8% for ibrutinib + BR vs placebo + BR (p = 0.0011). Investigator-determined responses by different levels of MRD are shown in Table 1. The percentage of pts with an MRD level < 1% was higher with ibrutinib + BR vs placebo + BR (32.2% vs 11.8%). Moreover, the percentage of pts with an MRD level < 0.1% was higher for ibrutinib + BR vs placebo + BR (24.6% vs 7.6%) suggesting that the depth of response with ibrutinib + BR was superior. Kaplan-Meier plots by MRD level (Figure 1) show that a lower MRD level was associated with a longer PFS. However, pts in the ibrutinib + BR arm had a more sustained response at every MRD level compared with pts in the placebo + BR arm. Conclusions Pts treated with ibrutinib + BR showed not only a higher ORR, but also a greater depth of response, with more CRs and a higher rate of resolution of LN, spleen, and BM involvement. Furthermore, the rate and depth of MRD negativity was improved, and appeared to last longer in pts treated with ibrutinib + BR compared with pts receiving placebo + BR. With a median follow up of 17 months in the ibrutinib + BR arm, no MRD-negative pts and few MRD-positive pts had progressed, thus evaluating a trend in PFS with MRD negativity is currently limited in this arm. Disclosures Cramer: Gilead: Other: Travel grant, Research Funding; Glaxo Smith Klein/Novartis: Research Funding; Astellas: Other: Travel grant; Mundipharma: Other: Travel grant; Janssen: Other: Travel grant, Research Funding, Speakers Bureau; Hoffman LaRoche: Other: Travel grant, Research Funding, Speakers Bureau. Off Label Use: Combination of bendamustine, obinutuzumab and ibrutinib for treatment of CLL. Fraser:Hoffman LaRoche: Consultancy, Honoraria; Janssen: Honoraria, Research Funding, Speakers Bureau; Celgene: Honoraria, Research Funding. Demirkan:Amgen: Consultancy; Celgene: Other: Travel reimbursement. Santucci Silva:Merck: Research Funding; Celgene: Research Funding; GSK: Research Funding; Janssen: Other: Travel reimbursement, Research Funding; Hoffman LaRoche: Other: Travel reimbursement, Research Funding; Novartis: Other: Travel reimbursement. Janssens:Mundipharma: Speakers Bureau; Roche: Consultancy, Speakers Bureau; Janssen: Consultancy. Goy:Allos, Biogen Idec, Celgene, Genentech, and Millennium. Gilead: Speakers Bureau; Celgene: Consultancy, Research Funding, Speakers Bureau. Mayer:Janssen: Research Funding. Dilhuydy:Roche: Honoraria, Other: Travel reimbursement; Janssen: Honoraria, Other: Travel reimbursement; Mundipharma: Honoraria. Bartlett:Millenium: Research Funding; Medimmune: Research Funding; Novartis: Research Funding; Pfizer: Research Funding; Genentech: Research Funding; ImaginAB: Research Funding; Astra Zeneca: Research Funding; Pharmacyclics: Research Funding; Janssen: Research Funding; Gilead: Consultancy; Seattle Genetics: Consultancy, Research Funding; Celgene: Research Funding. Rule:Roche: Consultancy, Other: Travel reimbursement; J&J: Consultancy, Other: Travel reimbursement, Research Funding; Celgene: Consultancy, Other: Travel reimbursement; Gilead: Research Funding. Sun:Janssen/J&J: Employment, Equity Ownership. Phelps:Janssen/J&J: Employment, Equity Ownership. Mahler:Janssen: Employment, Other: Travel reimbursement. Salman:Janssen/J&J: Employment, Equity Ownership. Schaffer:Janssen: Employment. Balasubramanian:Pharmacyclics LLC, an AbbVie Company: Equity Ownership; Janssen: Employment, Equity Ownership. Howes:Janssen/J&J: Employment, Equity Ownership. Hallek:AbbVie: Honoraria, Other: Speakers Bureau and/or Advisory Boards, Research Funding; Celgene: Honoraria, Other: Speakers Bureau and/or Advisory Boards, Research Funding; Pharmacyclics: Honoraria, Other: Speakers Bureau and/or Advisory Boards, Research Funding; Gilead: Honoraria, Other: Speakers Bureau and/or Advisory Boards, Research Funding; Boehringher Ingelheim: Honoraria, Other: Speakers Bureau and/or Advisory Boards; Roche: Honoraria, Other: Speakers Bureau and/or Advisory Boards, Research Funding; Mundipharma: Honoraria, Other: Speakers Bureau and/or Advisory Boards, Research Funding; Janssen: Honoraria, Other: Speakers Bureau and/or Advisory Boards, Research Funding.

Abstract Background: Treatment of multiple myeloma has evolved considerably in the past few years with availability of several news drugs as well as increasing use of multidrug combinations. These changes have no doubt led to the improved survival seen among patients with MM. We have previously shown that outcomes of patients intolerant or refractory to one of the IMiDs and bortezomib had a poor outcome. Since that time, other drugs of the same class as well as new classes of drugs have been introduced for the treatment of MM. We designed this retrospective study to estimate the outcomes in patients with relapsed myeloma, who have become refractory to the current generation IMiDs and proteasome inhibitors. Patients and Methods: Patients with relapsed multiple myeloma who have received at least 3 prior lines of therapy, is refractory to both an IMiD (lenalidomide or pomalidomide) AND a proteasome inhibitor (bortezomib or carfilzomib), and has been exposed to an alkylating agent were identified from multiple centers. The time patients met the above criteria was defined as T0, and details of all treatment regimens before and after T0 were collected using electronic CRFs. The study was approved by the IRB at the respective centers. Results: 543 patients were enrolled in this study; median age was 62 years (31-87) and 61% were males. Patients were enrolled from centers in North America (n=181), Europe (n=318), and Asia Pacific (n=44). Patients were diagnosed between 2006 and 2014, the median duration between diagnosis of myeloma and study entry (T0) was 3.1 years (0.3 to 9). The median (95% CI) estimated follow up from diagnosis and from T0 were 61 (57, 66) months and 13 (11, 15) months respectively. The median number of lines of therapy prior to T0 was 4 (3-13), 48% had a prior transplant. The median OS from T0 for the entire cohort was 13 (11, 15) months. For these 462 patients, the median number of recorded regimens was 2 (1-9). The overall response and the depth of response to each line of treatment following T0 are as shown in the table. The median (95% CI) PFS and OS from T0 was 5 (4, 6), and 15.2 (13, 17), respectively. The overall survival for the 81 patients with no treatment post T0 was only 2.1 months. In a multivariate analysis, duration from diagnosis to T0, ISS stage III and number of lines of therapy were all associated with inferior PFS, as well as OS, and in addition, serum creatinine>2 mg/dL at T0 also predicted inferior OS. Conclusions: The study provides the expected outcome following development of myeloma that is refractory to a PI and an IMiD. The outcomes of these patients appear to be better than we had seen historically in patients refractory/ intolerant to bortezomib and IMiDs, highlighting the increased treatment options available for these patients. However, there is decreasing response rate to sequential regimens highlighting the development of drug resistance. The data provides a bench mark for comparison of new therapies that are being evaluated in this disease. Table Table. Disclosures Dimopoulos: Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Genesis: Consultancy, Honoraria; Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees. Kastritis:Takeda: Consultancy, Honoraria; Genesis: Consultancy, Honoraria; Janssen: Consultancy, Honoraria; Amgen: Consultancy, Honoraria. Terpos:BMS: Consultancy, Honoraria; Janssen: Consultancy, Honoraria, Other: Travel expenses, Research Funding; Celgene: Honoraria; Takeda: Consultancy, Honoraria; Genesis: Consultancy, Honoraria, Other: Travel expenses; Amgen: Consultancy, Honoraria, Other: Travel expenses, Research Funding; Novartis: Honoraria. Hillengass:Sanofi: Research Funding; Novartis: Research Funding; Amgen: Consultancy, Honoraria; BMS: Honoraria; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Celgene: Honoraria. Leleu:TEVA: Membership on an entity's Board of Directors or advisory committees; Janssen: Honoraria; LeoPharma: Honoraria; Amgen: Honoraria; Bristol-Myers Squibb: Honoraria; Pierre Fabre: Honoraria; Celgene: Honoraria; Novartis: Honoraria; Takeda: Honoraria. Oriol:Janssen: Honoraria, Other: Expert board committee; Amgen: Honoraria, Other: Expert board committee. Cavo:Celgene: Consultancy, Honoraria; Millennium: Consultancy, Honoraria; Bristol-Myers Squibb: Consultancy, Honoraria; Janssen-Cilag: Consultancy, Honoraria; Amgen: Consultancy, Honoraria. Mateos:Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees; Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees; Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Bristol-Myers Squibb: Honoraria, Membership on an entity's Board of Directors or advisory committees. Vij:Shire: Consultancy; Takeda: Consultancy, Research Funding; Jazz: Consultancy; Karyopharma: Consultancy; Janssen: Consultancy; Novartis: Consultancy; Celgene: Consultancy; Bristol-Myers Squibb: Consultancy; Amgen: Consultancy, Research Funding. Lokhorst:Genmab: Research Funding; Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding. van de Donk:Amgen: Research Funding; Janssen: Research Funding; BMS: Research Funding; Celgene: Research Funding. Mark:Onyx: Research Funding, Speakers Bureau; Millenium: 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, Research Funding, Speakers Bureau. Ludwig:Amgen: Research Funding, Speakers Bureau; Takeda: Research Funding, Speakers Bureau; BMS: Speakers Bureau; Janssen: Speakers Bureau. Jagannath:Novartis: Consultancy; Janssen: Consultancy; Bristol-Myers Squibb: Consultancy; Celgene: Consultancy; Merck: Consultancy. Usmani:Array: Research Funding; Britsol-Myers Squibb: Consultancy, Research Funding; Skyline: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Takeda: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; BioPharma: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Onyx: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding; Pharmacyclics: Research Funding; Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Sanofi: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Amgen: Consultancy, Research Funding, Speakers Bureau; Millenium: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Novartis: Speakers Bureau. Dytfeld:Janssen Poland: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Research Funding; Amgen: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Membership on an entity's Board of Directors or advisory committees. Moreau:Novartis: Honoraria; Amgen: Honoraria; Celgene: Honoraria; Bristol-Myers Squibb: Honoraria; Takeda: Honoraria; Janssen: Honoraria, Speakers Bureau. Lee:Amgen: Membership on an entity's Board of Directors or advisory committees. Shustik:Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees; Millenium: Honoraria, Membership on an entity's Board of Directors or advisory committees; Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees. de la Rubia:Celgene: Consultancy; Bristol Myers: Consultancy; Amgen,: Consultancy; Janssen: Consultancy. Durie:Takeda: Consultancy; Amgen: Consultancy; Janssen: Consultancy.

Abstract Introduction Ibrutinib is a first-in-class, once-daily, oral, covalent inhibitor of Bruton's tyrosine kinase (BTK) that as a single agent has significantly improved overall survival in patients (pts) with both treatment naïve and relapsed/refractory chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL). In the phase 3 HELIOS trial, the addition of ibrutinib to bendamustine + rituximab (BR) resulted in an 80% reduction in disease progression or death (HR, 0.203, 95% CI, 0.150-0.276; p < 0.0001) and confirmed for the first time, in a randomized setting, the benefit of ibrutinib-based therapy compared with standard chemoimmunotherapy in previously treated pts (Chanan-Khan, et al. Lancet Oncol. 2016;17(2):200-11). Independent Review Committee assessed progression-free survival (PFS) at 18 months was 79% (95% CI: 73%-83%) in the ibrutinib +BR (I+BR) arm and 24% (95% CI: 18%-31%) in the placebo + BR (P+BR) arm. While the activity of ibrutinib is primarily in B-cells where it inhibits BTK-dependent survival pathways, it may also have significant effects on the immune system by exerting an effect on T-cells (by inhibition of interleukin-2-inducible kinase and related shift from Th2 to Th1-based immunity, which in turn affects Treg and Th17 activity) and via normalization of immune function, thus affecting tumor response. Here, we report changes in circulating T-cell immunophenotypes in a subset of pts treated with either I+BR or P+BR in the HELIOS study. Methods HELIOS is a randomized, double-blind, placebo-controlled, phase 3 study. Pts with active CLL/SLL following ≥ 1 prior therapy were randomized 1:1 to receive BR (≤ 6 cycles) with either ibrutinib (420 mg daily; n = 289) or placebo (n = 289). Pts with del17p (> 20% of cells) were excluded. Peripheral blood was collected at the start of the study, at Cycle 1, Day 15 (C1D15) and at the end of treatment/time of progressive disease (EOT/PD). From these samples, peripheral blood mononuclear cells (PBMC) were separated and cryopreserved. PBMC were subjected to flow-cytometric analysis of T-cell subsets including CD4, CD8 and markers indicative of Treg cells (CD25+CD127low) and Th17 cells (CCR4+CCR6+). In addition, expression of T-cell checkpoints ICOS, PD-1 and OX-40 by CD4 and CD8 cells were evaluated as an indicator of cell activation or activation/exhaustion. The findings from the HELIOS study reported here are based on analysis of paired samples (C1D1 and C1D15) of 29 CLL cases from the I+BR arm and 22 cases from the P+BR arm. The Mann-Whitney U test was applied to determine the significance of the differences in each of T-cell subtype between the two arms. Results Overall, there was a net increase in the percentage of CD3+ cells with treatment in both the I+BR-treated pts and P+BR-treated pts, which was observed as early as Day 15 (+12.0% and +11.42% of total lymphocytes, respectively, at C1D15 compared with C1D1; Figure 1). The EOT/PD samples showed a continued increase in the percentage of CD3+ cells in the I+BR pts, the majority of whom (11/12) were responders, while the opposite trend was observed in the P+BR patients (8/21 responders). Focusing on the early changes in the analysis of T-cell subsets, a pronounced decrease in the percentage of Th17 CD4+ cells was noted in the I+BR pts (mean: -2.49%) but in the P+BR pts, an increase of this subset (mean: +2.66%) was observed (p = 0.011; Figure 2). When comparing other CD4+ subsets, decreases in Treg cells were seen in both pt groups, with a corresponding increase in the T-cell activation marker ICOS. Less significant changes were observed in the other T-cell markers studied, however, a trend to increased PD-1 was seen in the P+BR pts but not in the I+BR pts. The safety profile in these pts was consistent with previous reports for the study. Conclusions These results suggest that the addition of ibrutinib to BR helped restore T-cell proportions in this subset of cases and it is noteworthy that this effect was visible even within 15 days of initiation of therapy. Data from the I+BR pts showed a pronounced decrease in the percentage of Th17 CD4+ cells, which are primarily pro-tumorigenic but may sometimes have anti-tumor effects, and a concomitant decrease in the percentage of Treg cells, which may explain the overall increase in T-cell activation. These findings may also be related to the observed increase in PFS with the addition of ibrutinib to BR reported in the trial. Disclosures Damle: Janssen Research & Development: Employment. Schaffer:Janssen Research & Development: Employment. Chaturvedi:Janssen Research & Development: Employment. Phelps:Johnson & Johnson: Employment, Equity Ownership. Aquino:Janssen Research & Development: Employment. Mahler:Janssen Research & Development: Employment. Salman:Janssen Research & Development: Employment, Equity Ownership, Other: Travel, Accommodations, Expenses. Howes:Janssen Research & Development: Employment. Loscertales:Janssen Research & Development: Consultancy; Roche: Consultancy; Gilead: Consultancy; AbbVie: Consultancy. Trneny:Gilead: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Roche: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; BMS: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Takeda: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen Research & Development: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Balasubramanian:Janssen Research & Development: Employment.

Abstract Background: In the pivotal FIRST trial, at the pre-specified planned analysis for progression-free survival (PFS), treatment (Tx) with lenalidomide plus low-dose dexamethasone until disease progression (Rd continuous) improved outcomes for transplant-ineligible patients (pts) with newly diagnosed multiple myeloma (NDMM) compared with melphalan, prednisone, and thalidomide (MPT), as well as Rd for 18 cycles (Rd18; Benboubker, NEJM 2014). Rd18 was added as a third arm to investigate whether Rd continuous Tx would control progression of NDMM longer than Rd18. Here, we present the final analysis of the overall survival (OS) data from the trial. Methods: Transplant-ineligible pts with NDMM were randomized 1:1:1 to Rd continuous (with lenalidomide given on days 1-21 of 28-day cycles until disease progression), Rd18 (with lenalidomide given on days 1-21 of eighteen 28-day cycles), or MPT (twelve 42-day cycles); both Rd18 and MPT were 72 weeks in duration. The primary endpoint was PFS and the key secondary endpoint was OS; the primary comparison was Rd continuous vs MPT. Other secondary endpoints included time to second therapy (TTST) and safety. Time from randomization to second progression or death (PFS2) was an exploratory analysis. Response assessment used for PFS and PFS2 analysis was determined by investigators based on International Myeloma Working Group criteria. Results: At the time of cutoff for the final OS analysis (January 21, 2016), 52 of the 535 pts in the Rd continuous arm and none of the pts in the Rd18 (n = 541) and MPT (n = 547) arms continued to receive Tx. The median follow-up for surviving pts was 67.0 months (range, 0-86.8 months). In the pre-specified final OS analysis for the primary comparison, a statistically significant advantage in OS was shown with Rd continuous over MPT (hazard ratio [HR], 0.78; 95% confidence interval [CI], 0.67-0.92; P = .00234; Table). OS for Rd continuous vs Rd18 was evaluated (HR, 1.02; 95% CI, 0.86-1.20). In this updated analysis, a PFS advantage continued to be seen for Rd continuous vs MPT (HR, 0.69; 95% CI, 0.59-0.79; P < .00001) and vs Rd18 (HR, 0.70; 95% CI, 0.60-0.81). Median TTST was longer for Rd continuous vs MPT (HR, 0.63; 95% CI, 0.54-0.73; Table). More pts in the Rd18 and MPT arms started second-line therapy (n = 377 and 381, respectively) compared with the Rd continuous arm (n = 299). Pts received a variety of Tx at progression, with bortezomib-based regimens the most common in the Rd continuous (n = 179; 59.9%), Rd18 (n = 208; 55.2%), and MPT (n = 170; 44.6%) arms. Pts who received bortezomib after Rd continuous or Rd18 had better outcomes than those who received it after MPT. PFS2 for Rd continuous was improved vs MPT (HR, 0.74; 95% CI, 0.64-0.85). Grade 3/4 adverse events (AEs) occurred in 86.3%, 80.2%, and 88.7% of the 532, 540, and 541 pts in the safety populations of the Rd continuous, Rd18, and MPT arms, respectively; the most common grade 3/4 AEs were neutropenia (29.5%, 26.5%, and 44.9%) and infections (31.6%, 21.9%, and 17.2%), and no new safety signals were seen compared with earlier analyses. Study discontinuation was most commonly due to disease progression and was less common in the Rd continuous vs Rd18 and MPT arms (50.7% vs 66.9% and 61.6%, respectively). Discontinuation due to AEs was similar across the Rd continuous, Rd18, and MPT arms (12.0%, 13.1%, and 13.9%). Solid tumor second primary malignancies (SPMs) occurred in 6.0, 6.9%, and 5.9% of pts, and hematologic malignancies occurred in 0.8%, 0.4%, and 2.6% of pts in the Rd continuous, Rd18, and MPT arms, respectively. Conclusions: Rd continuous significantly prolonged PFS and OS, and improved other secondary endpoints compared with MPT in transplant-ineligible pts with NDMM. Rd continuous also showed a PFS benefit compared with Rd18, delaying the time to next Tx. PFS2 outcomes suggest that Rd does not induce resistant relapses. Few hematologic malignancies occurred in the Rd arms, and the incidence of SPMs was similar between Rd continuous and Rd18. Rd continuous remains a standard of care for transplant-ineligible pts with NDMM. Disclosures Facon: Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: travel and expense, Speakers Bureau. Dimopoulos:Genesis: Consultancy, Honoraria; Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees. Dispenzieri:Celgene: Research Funding. Belch:Takeda: Honoraria; Janssen: Honoraria; Amgen: Honoraria; Celgene: Honoraria. Cavo:Bristol-Myers Squibb: Consultancy, Honoraria; Janssen-Cilag: Consultancy, Honoraria; Amgen: Consultancy, Honoraria; Celgene: Consultancy, Honoraria; Millennium: Consultancy, Honoraria. Weisel:BMS: Consultancy, Honoraria; Amgen: Consultancy, Honoraria; Janssen: Consultancy, Honoraria, Research Funding; Celgene: Consultancy, Honoraria, Research Funding; Onyx: Consultancy, Research Funding; Takeda: Consultancy, Research Funding; Novartis: Consultancy, Research Funding. Ludwig:Janssen: Speakers Bureau; BMS: Speakers Bureau; Takeda: Research Funding, Speakers Bureau; Amgen: Research Funding, Speakers Bureau. Bahlis:BMS: Honoraria; Amgen: Consultancy, Honoraria; Celgene: Consultancy, Honoraria, Other: Travel Expenses, Research Funding, Speakers Bureau; Janssen: Consultancy, Honoraria, Other: Travel Expenses, Research Funding, Speakers Bureau; Onyx: Consultancy, Honoraria. Delforge:Janssen: Honoraria; Celgene: Honoraria; Amgen: Honoraria. Cavenagh:Amgen: Consultancy, Speakers Bureau; Novartis: Consultancy, Speakers Bureau; Janssen: Consultancy, Speakers Bureau; Celgene: Consultancy, Speakers Bureau. Geraldes:Celgene: Consultancy, Honoraria; Amgen: Consultancy, Honoraria; BMS: Consultancy, Honoraria; Janssen: Consultancy, Honoraria. Oriol:Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees. De La Rubia:Amgen, Bristol, Celgene, Janssen: Consultancy, Speakers Bureau. White:Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Moreau:Celgene: Honoraria; Amgen: Honoraria; Takeda: Honoraria; Novartis: Honoraria; Janssen: Honoraria, Speakers Bureau; Bristol-Myers Squibb: Honoraria. Attal:janssen: Consultancy, Research Funding; amgen: Consultancy, Research Funding; celgene: Consultancy, Research Funding; sanofi: Consultancy. Ervin-Haynes:Celgene: Employment, Equity Ownership. Chen:Celgene: Employment, Equity Ownership. Houck:Celgene: Employment. Hulin:celgene: Honoraria; Bristol: Honoraria; Janssen: Honoraria; Amgen: Honoraria; takeda: Honoraria. Benboubker:Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees.

Abstract Background: Patients (pts) with refractory aggressive non-Hodgkin lymphoma (NHL) have poor outcomes with currently available therapies, with a complete response (CR) rate of 8%, a partial response (PR) rate of 18%, and median overall survival (OS) of 6.6 months (mo) as demonstrated in the 635 pt SCHOLAR-1 meta-analysis (Crump, ASCO 2016; abstract 7516). ZUMA-1 is the first multicenter trial of anti-CD19 chimeric antigen receptor (CAR) T cells in refractory, aggressive NHL (NCT02348216). The phase 1 portion of ZUMA-1 showed ongoing CRs at 12+ mos in 43% of pts (Locke, ESMO 2016; abstract 1048O). The pivotal phase 2 portion of ZUMA-1 comprises 2 cohorts based on tumor type: DLBCL (cohort 1) and primary mediastinal B-cell lymphoma or transformed follicular lymphoma (cohort 2). Here, we present results of a prespecified interim analysis from cohort 1. Methods: Pts received a target dose of 2 × 106 anti-CD19 CAR T cells/kg after a low-dose conditioning regimen of cyclophosphamide (500 mg/m2) and fludarabine (30 mg/m2) daily for 3 days. The primary endpoint is objective response rate (ORR) per 2007 IWG criteria. Key secondary endpoints include duration of response, frequency of adverse events (AEs), and levels of CAR T cells and serum cytokines. Key inclusion criteria include age ≥18 years, ECOG performance status (PS) 0-1, and refractory disease defined as progressive disease or stable disease as best response to last line of therapy, or disease progression ≤12 mos after autologous stem cell transplant (ASCT). Pts must have received a prior anti-CD20 antibody and an anthracycline-containing regimen. A prespecified interim analysis was to be conducted to determine early efficacy with a nominal alpha level of 0.017 in 50 treated pts in cohort 1 with a minimum follow-up of 3 mos. Results: In total, 111 pts from 22 institutions were enrolled and leukapheresed, and 101 pts received KTE-C19. As of August 24, 2016, 51 pts in cohort 1 were eligible for analysis. Median age was 58 years (range, 25-76), 73% were male, 71% had ECOG PS 1, 78% were refractory to ≥2 lines of therapy, 20% relapsed ≤12 mos of ASCT, and 61% were treated with ≥3 lines of prior therapy. KTE-C19 was successfully manufactured in 99% of pts enrolled. Average turnaround time from apheresis to receipt of KTE-C19 at the clinical site was 17.4 days. With an ORR of 76%, the study met the primary endpoint (P<0.0001; exact binomial test comparing observed ORR to a historical control assumption of 20%), with 47% CRs and 29% PRs. 92% of responses occurred within the 1st mo, and 39% of pts had ongoing responses (CR in 33%) at 3 mos. Responses were seen across key covariates, including refractory subgroup (refractory to chemotherapy=76%, relapse post ASCT=80%). Kaplan-Meier estimates of progression-free survival at 1 and 3 mos were 92% and 56%, respectively. The most common grade ≥3 treatment-emergent AEs were neutropenia (67%), anemia (39%), thrombocytopenia (29%), febrile neutropenia (27%), and encephalopathy (24%). Grade ≥3 cytokine release syndrome (CRS) and neurologic events occurred in 20% and 29% of pts, respectively. There was 1 grade 5 KTE-C19-related event of hemophagocytic lymphohistiocytosis. CAR T cells expanded within 14 days of KTE-C19 infusion, and peak expansion was associated with ongoing response at mo 3 (P=0.008). Pts who developed grade ≥3 neurological events had increased serum levels of IL-15 (P=0.0002), IL-6 (P=0.003); IL-10 (P=0.009) and IP-10 (P=0.0003). Cytokines/chemokines returned to baseline levels in most pts by day 28. Data from 93 pts with at least 1 mo of follow-up at the data cutoff will be presented. Conclusions: ZUMA-1 is the first reported multicenter trial of CAR T cell therapy in pts with refractory aggressive NHL. KTE-C19 induced a nearly 6-fold higher CR rate compared to historical outcomes in SCHOLAR-1. Efficacy strongly associated with peak CAR T levels. Central manufacturing, logistics, and AE management were successfully implemented across 22 sites, most with no prior CAR T therapy experience. Results from cohort 2 of ZUMA-1 are also presented (Abstract #998). KTE-C19 demonstrated significant clinical benefit in pts with no curative treatment options. Supported in part by funding from The Leukemia & Lymphoma Society Therapy Acceleration Program®. Drs Neelapu and Locke contributed equally to this study. Disclosures Neelapu: Kite Pharma: Membership on an entity's Board of Directors or advisory committees, Research Funding. Locke:Kite: Membership on an entity's Board of Directors or advisory committees. Miklos:pharmacyclics: Research Funding; Kite Pharma: Research Funding; Roche: Research Funding; Novartis: Research Funding. Jacobson:Kite: Membership on an entity's Board of Directors or advisory committees. Siddiqi:Pharmacyclics: Speakers Bureau; Janssen: Speakers Bureau; Seattle Genetics: Speakers Bureau. Lin:Mayo Clinic: Employment; Janssen: Research Funding. Timmerman:Bristol-Myers Squibb, Kite Pharma, Valor Biopharmaceuticals, Janssen: Research Funding; Seattle Genetics, Genmab, Celgene: Consultancy, Honoraria. Goy:COTA: Membership on an entity's Board of Directors or advisory committees; Janssen/Pharmacyclics: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Research funding for clinical trials through institution, Speakers Bureau; Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Research funding for clinical trials through institution; Acerta: Consultancy, Membership on an entity's Board of Directors or advisory committees; Takeda: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Genentech: Other: Research funding for clinical trials through institution. Smith:Abbvie: Research Funding; Celgene: Honoraria; Spectrum: Honoraria; Genentech: Honoraria. Deol:Jazz Pharmaceuticals: Consultancy. Avivi:Tel Aviv Sourasky Medical center: Consultancy, Other: consultancy to :BMS Roche. Westin:Genentech: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees; Amgen: Membership on an entity's Board of Directors or advisory committees; Spectrum: Membership on an entity's Board of Directors or advisory committees; ProNAi: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees. Chavez:Janssen: Speakers Bureau. Levy:Kite Pharma: Consultancy; Five Prime Therapeutics: Consultancy; Innate Pharma: Consultancy; Beigene: Consultancy; Corvus: Consultancy; Dynavax: Research Funding; Pharmacyclics: Research Funding. Reagan:Seattle Genetics: Research Funding. Bot:Kite Pharma: Employment, Equity Ownership. Rossi:Kite Pharma: Employment, Equity Ownership. Navale:Kite Pharma: Employment, Equity Ownership. Jiang:Kite Pharma: Employment, Equity Ownership. Aycock:Kite Pharma: Employment, Equity Ownership. Elias:Kite: Employment, Equity Ownership. Wiezorek:Kite Pharma: Employment, Equity Ownership. Go:Kite Pharma: Employment, Equity Ownership.

Abstract Background A meta-analysis by our group has shown an elevated risk of lymphoma with thiopurine therapy for IBD (Kandiel 2005 Gut). It summed referral data and population (pop) data, but the risk of lymphoma in referral centers may be skewed higher due to referral bias (Ang 2006 PMID 16531538). Since a previous meta-analysis presented in 2012 (Kotlyar 2012, DDW), there have been two large population based studies published (Pasternak 2013 Am J of Epidemiol, Abbas 2013 Gastroenterology). The latter study reported on a nationwide database of patients from the Veterans Affairs (VA) Hospitals from the United States. Aims Calculate the standard incidence rate of lymphoma in pts exposed to AZA/6-MP in population cohort studies and contrast these results to referral center studies. Methods We searched MEDLINE and the Cochrane Database for: “lymphoproliferative and thiopurines”; and “azathioprine and lymphoma”. Included citations were IBD cohort studies, evaluated cancer as an outcome, and pts. received AZA and/or 6-MP. Additionally a comprehensive search of the literature and abstracts from international meetings (2005-2013) was done. In our study additional data were extracted from the Spanish collaborative registry ENEIDA. Pooled standardized incidence ratios (SIRs) and 95% confidence intervals (CIs) were estimated. CIs assumed a Poisson distribution. To examine for heterogeneity, the deviance statistic from Poisson regression models was examined. Results There were 507 citations, and fifteen citations were included. Two studies (Korelitz and Kinlen) were obtained from Kandiel 2005, and Lewis 2001 was replaced by Armstrong 2010 as data were of the GPRD database. In referral studies (n=7), the SIR = 6.47 (95% CI: 3.77-10.36). In pop studies (n=8), the SIR = 2.27 (95% CI: 1.76-2.88). Overall the SIR was = 2.61 (95% CI: 2.08-3.23). Data from referral centers did not show significant heterogeneity (p=0.052), while pop studies did show significant heterogeneity (p=0.003). Results between referral and pop centers showed a significant difference (p<0.01). Conclusion Pts with IBD who are treated with thiopurines have approximately a 3-fold increased risk of lymphoma as compared to the general pop. The SIR of referral studies were seen to be significantly higher than those of population based studies, consistent with possible referral bias. Also, the addition of two population based studies have added 58,349 person-years of follow-up to our analysis.With a total of 84 lymphomas observed, and with total pt-years being 184,085, this study shows 2,191 pt-yrs per lymphoma in the exposed group. Meta-analysis of Standardized Incidence Ratios (SIR) Disclosures: Lewis: Pfizer: Consultancy; Centocor: Consultancy; Allos: Research Funding; Shire: Consultancy; Takeda: Research Funding; Amgen: Research Funding; Millenium: Consultancy; AstraZeneca: Consultancy; GlaxoSmithKline: Consultancy; Dark Canyon Labs: Consultancy; Roche Pharma AG: Consultancy. Beaugerie:Ferring : Speakers Bureau; Schering-Plough: Speakers Bureau; Merck : Speakers Bureau. Loftus:Pfizer: Consultancy; Genentech: Research Funding; Braintree: Research Funding; Abbott: Consultancy, Research Funding; UCB: Consultancy, Research Funding; Bristol-Myers Squibb: Consultancy, Research Funding; Shire: Membership on an entity’s Board of Directors or advisory committees; Centocor: Research Funding; Takeda: Research Funding; Amgen: Research Funding. Lichtenstein:Abbott: Research Funding; BristolMyers: Consultancy; Centocor: Consultancy, Research Funding; Elan: Research Funding; Ferring: Consultancy; MilleniumResearch: Consultancy; Procter and Gamble: Consultancy, Research Funding; Prometheus: Consultancy, Research Funding; Salix: Consultancy, Research Funding; Warner-Chilcotte: Consultancy, Research Funding; Schering-Plough: Consultancy; Shire: Consultancy, Research Funding; Wyeth: Consultancy; UCB: Consultancy.