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Abstract Introduction: Classical Hodgkin lymphoma (cHL) is characterized by Reed Sternberg (RS) cells surrounded by an extensive but ineffective inflammatory/immune cell infiltrate. Recent studies suggest that Hodgkin RS cells have developed mechanisms that exploit the programmed cell death-1 (PD-1) pathway to evade immune detection. In cHL, chromosome 9p24.1 gain is a frequent structural alteration that increases the gene dosage of the PD-1 ligands, PD-L1 and PD-L2, and their induction via JAK/STAT signaling. Epstein-Barr Virus (EBV) infection also increases the expression of the PD-1 ligands in EBV-positive cHL. Ligand binding to PD-1 receptor-positive activated T cells induces “T cell exhaustion,” a reversible inhibition of T cell activation and proliferation. Nivolumab (BMS-936558, Bristol-Myers Squibb) is a fully human IgG4 monoclonal PD-1 blocking antibody that potentiates anti-tumor T cell activity, and exhibits clinical efficacy in several solid tumors. We hypothesized that nivolumab may augment anti-tumor activity in patients with relapsed or refractory (R/R) cHL, including those who had failed brentuximab vedotin (BV), and evaluated the PD-1 blocking antibody. These are the first analyses being reported with PD-1 antibody for the treatment of cHL. Methods: Patients with R/R cHL were included as an independent cohort in a dose escalation and cohort expansion phase I study of nivolumab in lymphoma and multiple myeloma (MM). Results for patients with non-Hodgkin lymphoma and MM are reported separately. Patients with cHL received nivolumab 3 mg/kg every 2 weeks until confirmed tumor progression or excessive toxicity. Responses were evaluated using standard criteria. The primary endpoint was safety; key secondary endpoints included anti-tumor activity and expression of immunomodulatory proteins in tumor biopsies. Results: Twenty-three patients were enrolled with R/R cHL. Patients were heavily pre-treated, 87% had received ≥ 3 prior treatment regimens, 78% had prior autologous stem cell transplant (ASCT), and 78% had prior BV treatment. Drug-related adverse events (AEs) of any grade occurred in 78% of patients, the most common of which were rash (22%), decreased platelet count (17%), diarrhea, nausea, pruritus, fatigue, and pyrexia (each at 13%). Drug-related grade 3/4 AEs occurred in 22% of patients. Three patients experienced 1 serious AE each (grade 3 myelodysplastic syndrome [MDS], grade 3 pancreatitis, and grade 2 lymph node pain). The objective response rate (ORR) was 87% (20/23), with 4 patients (17%) achieving a complete response (CR) and 16 (70%) obtaining a partial response (PR). The remaining 3 patients (13%) had stable disease (SD). All 23 patients had a reduction in tumor burden at 1 or more efficacy assessments during treatment with nivolumab (Figure). Among the 18 patients who had previously failed BV, the ORR was 89% (16/18), with 6% (1/18) achieving CR and 83% (15/18) PR. Progression-free survival (PFS) rate at 24 weeks was 86% (95% CI, 62-95%). The median overall survival (OS) has not been reached (range, 21+ to 75+ weeks). Six of 23 patients elected to discontinue study treatment to undergo stem cell transplantation, 2 patients discontinued due to toxicities (MDS and thrombocytopenia in 1 patient; pancreatitis in 1 patient), 4 patients discontinued due to disease progression, and 11 patients continue on study as of June 16, 2014. In a subset of study patients (10/23), PD-L1 and PD-L2 copy numbers in RS cells were assessed using fixed tumor biopsy specimens and a 3-probe fluorescence in situ assay (PD-L1,PD-L2, and control centromeric probe). In all tumors, RS cells had copy gains of PD-L1 and PD-L2, as a result of either polysomy or amplification; these tumors also exhibited increased protein expression of PD-L1. RS cells were also largely positive for pSTAT3, indicative of active JAK/STAT signaling. Conclusions In patients with R/R cHL, nivolumab-mediated PD-1 blockade is safe and tolerable with a safety profile similar to that in solid tumors. The frequent and long-lasting responses in heavily pretreated, R/R patients, including those who have failed BV, highlight the importance of the PD-1 pathway in cHL, and the genetically defined sensitivity to PD-1 blockade in this disease. Based on these results, the FDA granted nivolumab breakthrough status in relapsed cHL and a large, multinational, phase II trial of this therapy is underway. Figure 1 Figure 1. Disclosures Armand: Merck: Consultancy. Off Label Use: Nivolumab was tested for the treatment of hematologic malignancies.. Ansell:Bristol-Myers Squibb: Research Funding. Lesokhin:Bristol-Myers Squibb: Consultancy, Research Funding. Timmerman:Bristol-Myers Squibb: Research Funding. Borrello:Bristol-Myers Squibb: Research Funding. Rodig:Bristol-Myers Squibb: Research Funding. Zhu:Bristol-Myers Squibb: Employment. Grosso:Bristol-Myers Squibb: Employment, Equity Ownership. Kim:Bristol-Myers Squibb: Employment. Shipp:Merck: Membership on an entity's Board of Directors or advisory committees; Pharmacyclics: Membership on an entity's Board of Directors or advisory committees; Bristol-Myers Squibb: Membership on an entity's Board of Directors or advisory committees, Research Funding; Gilead: Consultancy, Membership on an entity's Board of Directors or advisory committees; Bayer: Membership on an entity's Board of Directors or advisory committees; Sanofi: Research Funding; Janssen R&D: Membership on an entity's Board of Directors or advisory committees.

Abstract Introduction: Nivolumab, a fully human IgG4 monoclonal antibody targeting programmed death receptor-1, has recently been FDA approved for classical Hodgkin lymphoma (cHL) that has relapsed or progressed after autologous stem cell transplantation (ASCT) and post-transplantation brentuximab vedotin (BV). CheckMate 205 (NCT02181738) is a phase 2, international, multicohort study evaluating nivolumab monotherapy in patients with cHL after failure of ASCT. At minimum 6 months' follow-up of Cohort B (205B) which included patients who had received BV after disease recurrence following ASCT, objective response rate (ORR) per independent radiologic review committee (IRRC) was 66% and 6-month progression-free survival (PFS) was 77%, with an acceptable safety profile (Younes et al. Lancet Oncol 2016; Jul 20 [Epub ahead of print]). Here we report outcomes with longer follow-up (minimum 12-month follow-up) in 205B. Primary results from Cohort A, which enrolled patients who relapsed after ASCT but were BV-naïve, will also be presented for the first time as data were not available at time of abstract submission. Methods: CheckMate 205 was designed to evaluate the efficacy and safety of nivolumab monotherapy in patients with cHL who relapsed after ASCT in 3 cohorts: 205A (BV-naive patients; n = 63); 205B (BV after failed ASCT; n = 80); 205C (BV at any time prior to study drug; n = 100). Nivolumab was given at 3 mg/kg intravenously every 2 weeks until disease progression or unacceptable toxicity in 205A and 205B. The primary endpoint was IRRC-assessed ORR. Results: 80 patients were treated in Cohort 205B; the median age was 37 years (range 18-72). Patients had received a median of 4 prior regimens (range 3-15). At data cut-off (April 2016) with median duration of follow-up of 15.4 months (range 1.9-18.5), 43 patients (54%) still remained on therapy. IRRC-assessed ORR for patients in 205B was 68% (95% confidence interval [CI], 56%, 78%). CR and partial response (PR) rates per IRRC were 8% (3%, 16%) and 60% (48%, 71%), respectively. With longer follow-up, the median duration of response was prolonged to 13.1 months (95% CI, 8.7, not reached; range, 0.0+, 14.2+). The median duration of CR (DOCR) was not reached (95% CI, 4.6, not available [NA]; range, 0.7+, 10.4+) and the median duration of PR was 13.1 months (95% CI, 7.79, NA; range, 0.0+, 13.4+) (Table 1). IRRC median PFS was 14.8 months (95% CI, 11.3 months, NA); 12-month PFS was 54.6% (95% CI, 40.9%, 66.4%), and 12-month overall survival (OS) was 94.9% (median OS not reached). Of 37 patients (46%) who discontinued nivolumab, the most common reasons were disease progression (n = 19 [24%]), allogeneic stem cell transplant (n = 7 [9%]) and adverse events (n = 5 [6%]). Seventy-four patients (93%) had drug-related adverse events (AEs) of any grade. The most common drug-related AEs were fatigue (28%), infusion reaction (20%), arthralgia (15%), and rash (15%). 29% of patients had Grade 3-4 drug-related AEs; the most common were increased lipase (8%), neutropenia (5%), and increased aspartate aminotransferase (4%). The most common serious AEs were pyrexia, pneumonia, tumor progression, arrhythmia, infusion reaction, and meningitis (≤4% each). Conclusions: In this report with extended 12-month follow-up, longer remissions are noted following nivolumab monotherapy in relapsed cHL, including durable PRs in heavily pretreated patients. Nivolumab has an acceptable safety profile, similar to previously reported. Primary results following nivolumab monotherapy in BV-naïve patients with cHL who progressed after ASCT (Cohort 205A) will also be presented at the meeting. Study funding: Study funded by Bristol-Myers Squibb. Professional writing assistance was provided by K. Jesien of Caudex and funded by Bristol-Myers Squibb. Disclosures Timmerman: Seattle Genetics, Genmab, Celgene: Consultancy, Honoraria; Bristol-Myers Squibb, Kite Pharma, Valor Biopharmaceuticals, Janssen: Research Funding. Engert:Takeda, BMS: Consultancy, Honoraria, Research Funding. Armand:Bristol-Myers Squibb: Consultancy, Research Funding; Pfizer: Research Funding; Roche: Research Funding; Infinity Pharmaceuticals: Consultancy; Merck: Consultancy, Research Funding; Sequenta Inc: Research Funding. Collins:Takeda: Consultancy, Honoraria, Speakers Bureau. Kuruvilla:Roche Canada: Consultancy, Honoraria, Research Funding; Janssen: Consultancy, Honoraria; Abbvie: Consultancy, Honoraria; Amgen: Honoraria; Merck: Honoraria; BMS: Consultancy, Honoraria; Celgene: Consultancy, Honoraria; Gilead: Consultancy, Honoraria; Seattle Genetics: Consultancy, Honoraria; Lundbeck: Honoraria. Cohen:Millennium/Takeda: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees; Infinity: Consultancy, Membership on an entity's Board of Directors or advisory committees; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Pharmacyclics: Consultancy, Membership on an entity's Board of Directors or advisory committees; Seattle Genetics: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Bristol-Myers Squibb: Research Funding. Trneny:Roche, Celgene, Takeda, Janssen, Gilead, Bristol-Myers Squibb: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Roche, Celgene: Research Funding. De Boer:NKI-AVL: Employment. Shipp:Cell Signaling: Honoraria; Merck, Gilead, Takeda: Other: Scientific Advisory Board; Bayer: Research Funding; Bristol-Myers Squibb: Consultancy, Research Funding. Rodig:Bristol-Myers Squibb: Honoraria, Research Funding; Perkin Elmer: Membership on an entity's Board of Directors or advisory committees. Kato:Bristol-Myers Squibb: Employment. Sumbul:Bristol-Myers Squibb: Employment. Ansell:BMS, Seattle Genetics, Merck, Celldex and Affimed: Research Funding.

Abstract Introduction: Rituximab (R) improves survival in CLL when added to intensive chemotherapy (such as fludarabine and cyclophosphamide [FCR]), and has been shown to improve progression-free survival when given as maintenance therapy following first- or second-line chemoimmunotherapy. However, early phase 2 studies demonstrated only modest activity of R monotherapy (R mono), particularly at standard dose, and its use as a single agent for pts with CLL has remained controversial. Here we describe the characteristics and outcomes of pts with CLL receiving R mono in a real-world setting. Methods: The Connect CLL registry (NCT01081015), a multicenter, prospective observational cohort study, enrolled 1,494 pts with CLL between 2010-2014 from 179 community, 17 academic, and 3 government sites throughout the USA. Pts were ≥ 18 years and were enrolled ≤ 2 months after initiating any line of therapy (LOT). Pts were treated according to individual physician/patient decision making, and adherence to IWCLL standards cannot be determined. Bone marrow biopsy and CT scans were at the physician's discretion; responses were physician assessed and not centrally reviewed. For this analysis, pts were stratified by first (LOT1) or subsequent LOT (LOT≥2), and by treatment with R mono or other treatments (Tx). Kaplan-Meier methods were used to estimate event-free survival (EFS; event defined as death, progression/relapse, or transformation). A log-rank test was used to evaluate differences in EFS. A multivariate analysis of EFS in LOT1 pts was performed using the Cox regression model. Results: Of the pts enrolled, 105 (11.8%) pts in LOT1 and 81 (13.4%) pts in LOT≥2 received R mono. Of the pts receiving other Tx, 620/784 pts (79%) in LOT1 and 333/524 pts (64%) in LOT≥2 received R in combination. In LOT1, pts receiving R mono were older than pts receiving other Tx (74 vs 67 years; P < 0.0001); in LOT≥2 median ages were comparable (71 vs 70 years). Pts receiving R mono were more likely to have Rai stage 0-1 CLL than pts receiving other Tx, both in LOT1 (63.9% vs 51.8%; P = 0.05) and LOT≥2 (70.4% vs 49.9%; P = 0.005). The proportion of pts receiving R mono vs other Tx with a CCI score of ≥ 4 was similar in LOT1 (25.7% vs 22.8%) and LOT≥2 (32.1% vs 28.4%). Median absolute lymphocyte count at enrollment was lower in pts on R mono vs other Tx in LOT1 (27.7 vs 46.1 x 109/L) but similar in LOT≥2 (35.6 vs 30.2 x 109/L). A lower proportion of pts receiving R mono had FISH/cytogenetics performed at enrollment than pts receiving other Tx in LOT1 (48.6% vs 67.0%; P = 0.0002) and LOT≥2 (30.9% vs 49.6%; P = 0.002). The most common Tx regimens in LOT1 were FCR (25.9%), bendamustine plus R ([BR] 21.0%), R mono (11.8%), fludarabine plus R ([FR] 6.3%), and chlorambucil (4.6%); and in LOT≥2, BR (27.6%), R mono (13.4%), FCR (8.6%), bendamustine (7.4%), FR (4.1%), and ofatumumab (4.0%). The most common reason to initiate treatment in any LOT was bone marrow failure (LOT1, 44.8% vs 39.3%; LOT≥2, 37.0% vs 31.5%; R mono vs other Tx). Duration of therapy was shorter for pts receiving R mono vs other Tx in LOT1 (1.4 vs 4.1 months) and LOT≥2 (1.6 vs 3.3 months). In LOT1, responses were lower in pts on R mono vs other Tx: overall response rate (ORR) was 38.1% vs 64.2% (complete response [CR], 16.2% vs 41.2%; P < 0.0001). In LOT≥2, ORR was 25.9% vs 24.6% for pts on R mono vs other Tx (CR, 9.9% vs 11.5%; P = 0.68). Partial response did not differ significantly between pts receiving R mono vs other Tx in LOT1 and LOT≥2. Pts receiving R mono in LOT1 had inferior median EFS vs other Tx (34 vs 50 months; log-rank P = 0.04); however, after adjusting for factors such as ECOG status and del(17p) status, there was no difference in EFS (HR 0.932; P = 0.79). In pts in LOT≥2, median EFS was similar for R mono and other Tx (15 months for both groups; P = 0.93). Conclusions: Pts receiving R mono as frontline CLL therapy were older than pts receiving other Tx. They also had lower stage disease and lower lymphocyte counts, a shorter duration of treatment, and inferior response rates. Pts receiving R mono in relapsed CLL, more closely approximated pts receiving other Tx in terms of age. Despite the shorter duration of therapy for pts receiving R mono in LOT1 and LOT≥2, both groups had similar ORR and EFS in LOT≥2. These data reinforce the idea that R mono is inadequate as frontline therapy in progressive CLL, and demonstrate the opportunity for improvement in relapsed/refractory disease with novel agents relative to traditional chemoimmunotherapy approaches. Disclosures Sharman: Celgene: Research Funding; Gilead: Research Funding; Pharmacyclics: Research Funding; Acerta: Research Funding; TG Therapeutics: Research Funding; Seattle Genetics: Research Funding. Davids:Pharmacyclics: Membership on an entity's Board of Directors or advisory committees, Research Funding; Genentech: Membership on an entity's Board of Directors or advisory committees, Research Funding; Infinity: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; TG Therapeutics: Membership on an entity's Board of Directors or advisory committees, Research Funding; AbbVie, Janssen, Gilead: Consultancy; Celgene Corporation: Consultancy. Farber:Seattle Genetics: Research Funding. Grinblatt:Celgene Corporation: Consultancy, Speakers Bureau. Lamanna:Gilead: Research Funding; AbbVie: Research Funding; Genentech: Research Funding; Infinity: Research Funding; Pronai: Research Funding; Celgene Corporation: Research Funding. Mato:TG Therapeutics: Consultancy; Abbvie: Research Funding; Acerta Pharma: Research Funding; Gilead Sciences: Research Funding; ProNAi: Research Funding; TG Therapeutics: Research Funding; Theradex: Research Funding; Pharmacyclics: Consultancy; Gilead Sciences: Consultancy; Abbvie: Consultancy. Nabhan:Astellas: Research Funding; Seattle Genetics: Research Funding; Cardinal Health: Consultancy; Infinity: Consultancy; Abbvie: Consultancy; Genentech: Consultancy, Research Funding; Celgene Corporation: Consultancy, Research Funding. Sullivan:Celgene Corporation: Employment, Equity Ownership. Flick:Celgene Corporation: Employment, Equity Ownership. Kiselev:Celgene Corporation: Employment, Equity Ownership. Bhushan:Celgene Corporation: Employment, Equity Ownership. Swern:Celgene: Employment, Equity Ownership. Flowers:Seattle Genetics: Research Funding; Optum Rx, Seattle Genetics, Genentech/Roche: Consultancy; Celgene Corporation: Consultancy, Honoraria; Spectrum, Janssen, Infinity, AbbVie, Acerta, Pharmacyclics, TG Therapeutics: Research Funding; Millennium: Consultancy, Research Funding; Gilead: Consultancy, Research Funding.

Abstract Background Brentuximab vedotin (BV) is an antibody-drug conjugate directed against CD30, a receptor that engages the CD30 ligand expressed on immune cells in the tumor microenvironment, promoting tumor cell growth (Montanari 2014, Hansen 2014). Through disruption of the microtubule network, BV induces apoptotic cell death, and may initiate an antitumor immune response (i.e., immunogenic cell death) through the induction of endoplasmic reticulum (ER) stress (Gardai 2015). Nivolumab is a fully human monoclonal PD-1 blocking antibody that prevents tumor immune evasion. Both agents have independent high single-agent response rates in patients (pts) with relapsed or refractory (R/R) Hodgkin lymphoma (HL), and when used in combination, may exhibit mechanistic synergy. Given the demonstrated efficacy of both BV and nivolumab, together these agents could yield improved CR rates prior to ASCT in pts with R/R HL, and potentially better long-term outcomes. Methods A phase 1/2 study is ongoing to evaluate the safety and antitumor activity of BV administered in combination with nivolumab as first salvage therapy in pts with R/R classical HL after standard frontline chemotherapy (NCT02572167). Adult pts are treated in 21-day cycles for up to 4 cycles (12 weeks). Pts receive 1.8 mg/kg BV on Cycle 1 Day 1, and 3 mg/kg nivolumab on Cycle 1 Day 8. For cycles 2 through 4, BV and nivolumab are administered on Day 1 of each cycle at the same doses. After completion of the Cycle 4 response assessment, pts are eligible to undergo ASCT. Investigator assessment of lymphoma response and progression is per the Lugano Classification Revised Staging System for malignant lymphoma (Cheson 2014). Results Twenty-five pts (60% female) with a median age of 32 years (range, 18-69) have been enrolled to date. Sixty percent of pts have relapsed disease, 36% have primary refractory disease (failure to achieve CR with frontline therapy, or relapse within 3 months of completing frontline therapy), and 1 pt (4%) has unknown status. At the time of enrollment, 32% of pts presented with extranodal disease and 16% with bulky disease. At the time of the data extract, 23 pts had received treatment. An increased incidence of infusion-related reactions (IRRs) was observed at the start of combination treatment in Cycle 2 during the BV infusion leading to 1 dose delay. Premedication with corticosteroids (hydrocortisone 100 mg or equivalent) and antihistamines at Cycles 2-4 was instituted through a protocol amendment. Six pts have completed combination treatment, and all have achieved an objective response (ORR, 100%), with 3 of 6 achieving a complete metabolic response (CmR, 50%). All 6 pts have proceeded directly to ASCT. Median number of CD34+ cells collected was 12.9 x106 cells/kg (range, 5-26) in a mean number of 1.7 apheresis sessions (range, 1-2). Adverse events (AEs) for all pts are summarized prior to ASCT. Eighteen of the 23 treated pts (78%) experienced adverse events (AEs). Fifteen pts (65%) had AEs ≤ Grade 2 in severity and 3 pts (13%) experienced Grade 3 AEs. No pts experienced Grade 4 AEs pre-ASCT. Fatigue was the most common AE occurring in 35% of pts, followed by nausea (26%), rash (22%), dyspnea, myalgia, and pruritus (17% each). One pt experienced a treatment-related serious adverse event (SAE) of dehydration, hypercalcemia, and acute kidney injury. Immune-related adverse events (IrAEs) were experienced by 3 pts; 2 pts who experienced Grade 1 rash treated with topical steroids, and 1 pt who experienced Grade 1 hypothyroidism. No pts have discontinued treatment prematurely. In addition to Reed-Sternberg cells, CD30 is expressed on activated T cells. Preliminary biomarker data indicate a BV-induced decrease in the percentage of CD4+ T regulatory (Treg) cells at C1D8, with no decrease in proliferating CD8+ T cells, and no significant decrease observed in the percentage of CD4+ Th1 cells compared to baseline for 5 of 6 pts (83%). Nivolumab induced a robust expansion of T cells at C1D15. Conclusions Early data suggest the combination of BV and nivolumab is an active and well-tolerated salvage therapy in pts with R/R HL. While an elevated incidence of IRRs has been observed, toxicities with this regimen appear to be tolerable overall. The preliminary antitumor activity suggests this combination may be a promising option for R/R HL pts. Updated results will be shared at the time of presentation. Disclosures Herrera: Pharmacyclics: Research Funding; Merck: Research Funding; Immune Design: Research Funding; Genentech: Research Funding; Adaptive Biotechnologies: Research Funding; Seattle Genetics: Research Funding. Bartlett:Gilead: Consultancy. Moskowitz:BMS: Honoraria, Research Funding; Seattle Genetics: Honoraria, Research Funding. Feldman:Abbvie/Pharmacyclics/Janssen: Speakers Bureau; Seattle Genetics: Consultancy, Research Funding, Speakers Bureau; Celgene: Consultancy, Speakers Bureau. LaCasce:Seattle Genetics: Research Funding; Forty Seven Inc.: Consultancy. Ansell:Bristol Myers Squibb: Research Funding; Seattle Genetics: Research Funding; Celldex: Research Funding; Affimed: Research Funding. Fenton:Seattle Genetics: Employment, Equity Ownership. Kato:Bristol-Myers Squibb: Employment. Fong:Seattle Genetics: Employment, Equity Ownership.

Abstract Introduction: REGN1979 is a hinge-stabilized CD20xCD3bispecific full-length antibody (Ab) based on an IgG4isotype modified to reduce Fc binding. It is designed to bind T cells (via CD3) and CD20-expressing cells. Cross-linking results in specific, local T cell activation and engagement ofcytolytic functions, independent of T cell receptor mediated recognition. This mechanism of action (MOA) is distinct from approved anti-CD20 Abs, and may provide additional therapeutic benefit. This report describes safety and clinical outcomes in 25 patients (pts) treated with REGN1979. Methods: The study uses a 3+3 design to assess safety, pharmacokinetics (PK), pharmacodynamics (PD), and activity of REGN1979 inpts with NHL and CLL, in separate dose escalation cohorts. REGN1979 is administered IV over 1-4 hours, weekly (QW) for 4 doses followed by every 4 weeks (Q4W) for 5 doses. Each dose level (DL) consists of an initial starting dose followed by a higher (step-up) dose.Pts with either progressive disease (PD) after initial response or suboptimal initial response could be retreated. Results: As of clinical cut-off, 25pts had been enrolled and treated with REGN1979 at flat doses ranging from 0.03 - 3.0 mg: 20pts with NHLand 5pts with CLL. NHL subtypes included DLBCL (n=12), FL (n=6), and MCL (n=2). Allpts hada medianof3 (range 1-7) prior regimens, and received a median of 5 (range 2-9) doses of REGN1979. Sixpts remained on initial treatment, 3pts completed treatment, and 16pts discontinued treatment (14 for PD; 2 subject decision). Of 4pts who entered retreatment, 2pts remained ongoing. The most common treatment-related treatment-emergent AEs (TR-TEAEs) were pyrexia (56%), infusionrelated reaction (IRR) (40%), chills (36%), cytokine release syndrome (CRS) (28%), fatigue (24%), tachycardia (24%), hypomagnesaemia (20%) and hypotension (20%). Grade >= 3 TR-TEAEs occurred in 8 pts(32%): IRR (12%), CRS (8%), hypotension (8%), and pyrexia, tachycardia, dyspnea, anemia, hypoxia, hypertension, tachypnea, transaminases increased, and tumor pain each in 1 pt(4%). All were grade 3 with the exception of 1 ptwith grade 4 hypotension. There were no protocol-defined DLTs, nor grade 5 TEAE. No ptsdiscontinued REGN1979 due to TR-TEAE. IRR and CRS events were most commonly reported with the first administration of both initial and step-up dose with incidence and severity decreasing with increasing exposure. Tenptsreported at least one TR-SAE: CRS (24%), IRR (20%), and increased AST and tumor pain, each in 1pt(4%). Threeptswith aggressive lymphoma who discontinued REGN1979 due to PD died of their disease within 30 days of their last dose. Notably, modifications to pre-medication(s) and drug administration instructions have improved tolerability (fewer and less severe IRR/CRS). No clinically significant CNS TEAEs have been observed. CT-based (Cheson, 2007) anti-tumor activity was observed in 11 ptswith NHL: PR [n=4,median duration of 50d];SD [n=7, median duration of >196d]. The overall response rate (ORR) in NHL ptsacross DLs was 20%. In 2 highest dose levels, ORR was 27% (Fig 1). Of the 14pts evaluated by PET, 4pts had a partial metabolic response, withmedian duration of 244d perLugano Criteria. Twopts with CLL attained SD as best overall response. PK: REGN1979 concentrations in serum increased with increasing DL and were variable across pts. Variability was less at higher DLs and also decreased over time during therapy. At DLs tested, REGN1979 concentrations did not notably increase over time during treatment. PD/Cytokines: At the lowest dose tested, 0.03 mg, transient B-cell depletion was observed inpts with measurable circulating B cells.Samples from 12pts were available for cytokine analysis. Interim analysis indicates REGN1979 induces cytokine release as expected based on MOA. An increase in IL-6, IL-10 and to lesser extent IFN-γ was observed. The magnitude of cytokine response generally correlated with symptomatic IRR/CRS. Conclusion: REGN1979 demonstrated an acceptable safety profile at flat doses of 0.03 - 3.0 mg (< 1% of rituximab dose) inpts with NHL and CLL. Most TEAEs were associated with IRR/CRS, and were managed with supportive therapy and modification to REGN1979 administration. No clinically significant neurological toxicity was observed. Preliminary antitumor activity demonstrates increased activity at higher doses. Dose escalation and treatment schedule optimization continue. Disclosures Brown: Acetylon, Gilead: Research Funding; Celgene, Roche/Genentech, Gilead, Infinity, Janssen, Pharmacyclics, ProNai, Sun BioPharma: Consultancy. Arnason:Gilead: Consultancy. O'Brien:Pharmacyclics, LLC, an AbbVie Company: Consultancy, Honoraria, Research Funding; Janssen: Consultancy, Honoraria. Chavez:Janssen: Speakers Bureau. Ansell:BMS, Seattle Genetics, Merck, Celldex and Affimed: Research Funding. Topp:Amgen: Consultancy, Honoraria, Other: travel, Speakers Bureau; Roche: Honoraria, Other: travel; Boehringer: Consultancy, Other: Travel, Research Funding; Jazz: Consultancy; Pfizer: Consultancy, Other: Travel. Adriaens:Regeneron Pharmaceuticals Inc.: Employment, Equity Ownership. Ufkin:Regeneron Pharmaceuticals Inc.: Employment, Equity Ownership. Kostic:Regeneron Pharmaceuticals Inc.: Employment, Equity Ownership. Paccaly:Regeneron Pharmaceuticals Inc.: Employment, Equity Ownership. Gao:Regeneron Pharmaceuticals Inc: Employment, Equity Ownership. Trail:Regeneron Pharmaceuticals Inc: Employment, Equity Ownership. Lowy:Regeneron Pharmaceuticals Inc: Employment, Equity Ownership. Brownstein:Regeneron Pharmaceuticals Inc: Employment, Equity Ownership.

Background: Multiple myeloma (MM) is common among the elderly, with 35% of patients (pts) diagnosed being aged ≥75 years (y). With increasing overall life expectancy, the incidence and prevalence of newly diagnosed and previously treated MM patients ≥80 y is expected to increase over time. Because elderly pts are often excluded from clinical trials, data focused on their treatment patterns and clinical outcomes are lacking. The Connect® MM Registry (NCT01081028) is a large, US, multicenter, prospective observational cohort study of pts with newly diagnosed MM (NDMM) designed to examine real-world diagnostic patterns, treatment patterns, clinical outcomes, and health-related quality of life patient-reported outcomes. This analysis reviews treatment patterns and outcomes in elderly pts from the Connect MM Registry. Methods: Pts enrolled in the Connect MM registry at 250 community, academic, and government sites were included in this analysis. Eligible pts were adults aged ≥18 y with symptomatic MM diagnosed ≤2 months before enrollment, as defined by International Myeloma Working Group criteria; no exclusion criteria were applied. For this analysis, pts were categorized into 4 age groups: <65, 65 to 74, 75 to 84, and ≥85 y. Pts were followed from time of enrollment to the earliest of disease progression (or death), loss to follow-up, or data cutoff date of February 7, 2019. Descriptive statistics were used for baseline characteristics and treatment regimens. Survival outcomes were analyzed using Cox regression. Time to progression (TTP) analysis excluded causes of death not related to MM. Results: Of 3011 pts enrolled (median age 67 y), 132 (4%) were aged ≥85 y, and 615 (20%) were aged 75-84 y at baseline. More pts aged ≥85 y had poor prognostic factors such as ISS stage III disease and reduced hemoglobin (<10 g/dL or >2 g/dL <LLN) compared with other age groups, although no notable differences between creatinine and calcium levels were observed across age groups (Table). A lower proportion of elderly pts (75-84 and ≥85 y) received triplet regimens as frontline therapy. More elderly pts received a single novel agent, whereas use of 2 novel agents was more common in younger pts (Table). The most common frontline regimens among elderly pts were bortezomib (V) + dexamethasone (D), followed by lenalidomide (R) + D, whereas those among younger pts included RVD, followed by VD and CyBorD (Table). No pt aged ≥85 y, and 4% of pts aged 75-84 y received high-dose chemotherapy and autologous stem cell transplant (vs 61% in the <65 y and 37% in the 65-74 y age group). The most common maintenance therapy was RD in pts ≥85 y (although the use was low) and R alone in other age groups (Table). In the ≥85 y group, 27%, 10%, and 4% of pts entered 2L, 3L, and 4L treatments respectively, vs 43%, 23%, and 13% in the <65 y group. Progression-free survival was significantly shorter in the ≥85 y age group vs the 75-84 y age group (P=0.003), 65-74 y age group (P<0.001), and <65 y age group (P<0.001; Fig.1). TTP was significantly shorter in the ≥85 y group vs the <65 y group (P=0.020); however, TTP was similar among the 65-74 y, 75-84 y, and ≥85 y cohorts (Fig. 2). Overall survival was significantly shorter in the ≥85 y group vs the 75-84 y, 65-74 y, and <65 y groups (all P<0.001; Fig. 3). The mortality rate was lowest (46%) during first-line treatment (1L) in pts aged ≥85 y (mainly attributed to MM progression) and increased in 2L and 3L (47% and 54%, respectively); a similar trend was observed in the younger age groups. The main cause of death was MM progression (29% in the ≥85 y vs 16% in the <65 y group). Other notable causes of death in the ≥85 y group included cardiac failure (5% vs 2% in <65 y group) and pneumonia (5% vs 1% in <65 y group). Conclusions: In this analysis, elderly pts received similar types of frontline and maintenance regimens as younger pts, although proportions varied with decreased use of triplet regimens with age. Considering similarities in TTP across the 65-74 y, 75-84 y, and ≥85 y cohorts, these real-world data support active treatment and aggressive supportive care of elderly symptomatic pts, including with novel agents. Additionally, further clinical studies specific to elderly patients with MM should be explored. Disclosures Lee: Amgen: Consultancy, Research Funding; GlaxoSmithKline plc: Research Funding; Sanofi: Consultancy; Daiichi Sankyo: Research Funding; Celgene: Consultancy, Research Funding; Takeda: Consultancy, Research Funding; Janssen: Consultancy, Research Funding. Ailawadhi:Janssen: Consultancy, Research Funding; Takeda: Consultancy; Pharmacyclics: Research Funding; Amgen: Consultancy, Research Funding; Celgene: Consultancy; Cellectar: Research Funding. Gasparetto:Celgene: Consultancy, Honoraria, Other: Travel, accommodations, or other expenses paid or reimbursed ; Janssen: Consultancy, Honoraria, Other: Travel, accommodations, or other expenses paid or reimbursed ; BMS: Consultancy, Honoraria, Other: Travel, accommodations, or other expenses paid or reimbursed . Jagannath:AbbVie: Consultancy; Merck & Co.: Consultancy; Bristol-Myers Squibb: Consultancy; Karyopharm Therapeutics: Consultancy; Celgene Corporation: Consultancy; Janssen Pharmaceuticals: Consultancy. Rifkin:Celgene: Membership on an entity's Board of Directors or advisory committees; Takeda: Membership on an entity's Board of Directors or advisory committees; Amgen: Membership on an entity's Board of Directors or advisory committees. Durie:Amgen, Celgene, Johnson & Johnson, and Takeda: Consultancy. Narang:Celgene: Speakers Bureau. Terebelo:Celgene: Honoraria; Jannsen: Speakers Bureau; Newland Medical Asociates: Employment. Toomey:Celgene: Consultancy. Hardin:Celgene: Membership on an entity's Board of Directors or advisory committees. Wagner:Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees; American Cancer Society: Other: Section editor, Cancer journal. Omel:Celgene, Takeda, Janssen: Other: Patient Advisory Committees. Srinivasan:Celgene: Employment, Equity Ownership. Liu:TechData: Consultancy. Dhalla:Celgene: Employment. Agarwal:Celgene Corporation: Employment, Equity Ownership. Abonour:BMS: Consultancy; Celgene: Consultancy, Research Funding; Takeda: Consultancy, Research Funding; Janssen: Consultancy, Research Funding.

Introduction: The phase 3 international, randomized, double-blind ROBUST clinical trial (NCT02285062) compared progression-free survival between patients with previously untreated ABC-type DLBCL treated with placebo plus rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (placebo-R-CHOP) versus lenalidomide + R-CHOP (R2-CHOP) for 6 21-day cycles. HRQoL, as measured by the Functional Assessment of Cancer Therapy-Lymphoma (FACT-Lym) and the EuroQoL 5-dimension 3-level (EQ-5D-3L) patient-reported questionnaires, was evaluated as a secondary endpoint for the 2 treatment arms. Methods: For each treatment group, FACT-Lym and EQ-5D-3L scores were measured at baseline (BL), mid-, end-of-treatment (EOT), and post-treatment, in 12-week intervals from Week 34 onward. Patients were evaluated if they had completed BL and ≥ 1 post-BL calculable FACT-Lym subscale measurements. Non-inferiority (NI) of R2-CHOP versus placebo-R-CHOP was measured for 4 key FACT-Lym subscales: Physical Well-Being (PWB), Additional Concerns (AC), Functional Well-Being (FWB), and Trial Outcome Index (TOI). NI was assessed at EOT (typically 3-4 weeks after completing Cycle 6) and at post-treatment follow-up at Week 34 by analysis of covariance (ANCOVA). The NI margins were prespecified as 1 less than the higher published minimal important difference (MID) for each subscale. Since a range of MIDs have been published, a more conservative value was also used as a sensitivity analysis. Time to improvement (TTI), using published responder definitions, was also assessed for the FACT-Lym subscales. EQ-5D-3L scores were summarized descriptively. Results: Demographic and baseline disease characteristics were balanced across the 2 treatment arms (N = 285 per arm). The percentage of patients who completed the FACT-Lym out of the expected population remained &gt; 85% at all time points with &gt; 50 patients still on the study in each treatment arm up to Week 142. Completion rates and reasons for missing assessments were balanced across the 2 treatment arms. FACT-Lym subscale scores were generally higher after EOT, similar for both treatment groups, and mean changes from BL were close to or above MID (where defined), except for the Social/Family Well-Being subscale. Mean differences in FACT-Lym TOI between treatment arms are shown in Table 1. As positive treatment differences favor R2-CHOP and -10 was the predefined NI margin, NI was demonstrated for the FACT-Lym TOI subscale at both EOT and Week 34 assessments. Superiority of R2-CHOP was demonstrated at EOT as the confidence interval (CI) lies completely above 0 (P &lt; 0.04); however, this difference was not clinically meaningful. Furthermore, NI was also demonstrated when using the sensitivity analysis margin of -4.5. ANCOVA models were also fitted for the other key subscales of PWB, AC and FWB (Table 2). NI was demonstrated for all NI margins at both time points for the PWB and AC subscales. The FACT-Lym FWB subscale demonstrated NI for both margins at EOT and Week 34 for the primary NI margin of -2 based on the MID minus 1, but did not demonstrate NI when an NI margin of -1, based on an alternative published MID, was used. The TTI curves and associated summary statistics were similar for the 2 treatment arms, with a median TTI for the FACT-Lym TOI of 21 weeks (95% CI 15-22) for patients treated with R2-CHOP and 18 weeks (95% CI 15-22) for patients treated with placebo-R-CHOP. Mean EQ-5D-3L visual analogue scale (VAS) and Utility Index (UK weights) change from baseline scores were higher in both treatment arms and the mean changes were above, or close to, the published MID (7 for VAS, 0.1 for Utility Index) at EOT assessments. Prespecified sensitivity and subgroup analyses supported the conclusions from the primary HRQoL analyses. Conclusions: The predefined NI levels were met for the 4 key FACT-Lym subscales. Similar results were observed across the other HRQoL assessments, sensitivity, and subgroup analyses. Adding lenalidomide to the R-CHOP regimen did not adversely affect the HRQoL of patients with DLBCL as measured by FACT-Lym and EQ-5D-3L. These data serve as a benchmark for future clinical trials combining next-generation immunomodulatory drugs with standard R-CHOP to improve clinical efficacy while maintaining HRQoL in patients with DLBCL. HRQoL analyses should become an integral part of future clinical trials of novel combination regimens in DLBCL. Disclosures Chiappella: Roche: Speakers Bureau; Teva: Speakers Bureau; Servier: Other: advisory board, Speakers Bureau; Janssen: Other: advisory board, Speakers Bureau; Celgene: Other: advisory board, Speakers Bureau. Cocks:Adelphi Values: Employment; Amgen: Consultancy; BMS: Consultancy; Celgene Corporation: Consultancy; Endomag Ltd.: Consultancy. Greenwood:Adelphi Values: Employment. Williams:Adelphi Values: Employment. Scott:Celgene: Consultancy; Roche/Genentech: Research Funding; NanoString: Patents & Royalties: Named inventor on a patent licensed to NanoSting [Institution], Research Funding; Janssen: Consultancy, Research Funding. Yamamoto:SymBio: Research Funding; Ono: Consultancy, Honoraria, Research Funding; Otsuka: Honoraria; Sanofi: Honoraria; Astra-Zeneca: Consultancy, Research Funding; Sumitomo Dainippon: Honoraria; Chugai: Consultancy, Honoraria, Research Funding; Eisai: Consultancy, Honoraria, Research Funding; Janssen: Honoraria; Gilead Sciences: Research Funding; Solasia Pharma: Research Funding; Bayer: Research Funding; Celgene Corporation: Consultancy, Honoraria, Research Funding; ARIAD: Research Funding; Pfizer: Honoraria; Bristol-Myers Squibb: Consultancy, Honoraria; Kyowa Kirin: Honoraria; MSD: Consultancy, Honoraria; Mundipharma: Consultancy, Honoraria, Research Funding; AbbVie: Consultancy, Research Funding; Meiji Seika Pharma: Consultancy, Honoraria; HUYA/IQVIA Services Japan: Consultancy, Honoraria; Novartis: Honoraria, Research Funding; Incyte: Research Funding; Takeda: Consultancy, Honoraria, Research Funding. Jurczak:Bayer: Research Funding; Takeda: Research Funding; Gilead: Research Funding; Sandoz: Membership on an entity's Board of Directors or advisory committees, Research Funding; Morphosys: Research Funding; Incyte: Research Funding; Celgene Corporation: Research Funding; Loxo: Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding; Roche: Research Funding; AstraZeneca: Membership on an entity's Board of Directors or advisory committees, Research Funding; Celtrion: Research Funding; Novo Nordisk: Research Funding; Servier: Research Funding; TG Therapeutics: Research Funding. Özcan:Sanofi: Other: Travel support; Abdi Ibrahim: Other: Travel support; BMS: Other: Travel support; Takeda: Honoraria, Other: Travel support, Research Funding; Archigen: Research Funding; Roche: Other: Travel support, Research Funding; Bayer: Research Funding; Janssen: Other: Travel support, Research Funding; Celgene Corporation: Research Funding, Travel support; AbbVie: Other: Travel support, Research Funding; MSD: Research Funding; Novartis: Research Funding; Jazz: Other: Travel support; Amgen: Honoraria, Other: Travel support. Belada:Roche: Consultancy; Gilead Sciences: Consultancy; Takeda: Consultancy. Margunato-Debay:Celgene Corporation: Employment, Equity Ownership. Czuczman:Celgene Corporation: Employment, Equity Ownership. Zhai:Celgene Corporation: Employment, Equity Ownership. Braverman:Celgene Corporation: Employment. Vitolo:Juno Therapeutics: Membership on an entity's Board of Directors or advisory committees; Abbvie: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Janssen: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Celgene: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Novartis: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Kite: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; F. Hoffmann-La Roche: Speakers Bureau; Gilead: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Nowakowski:Selvita: Membership on an entity's Board of Directors or advisory committees; NanoString: Research Funding; MorphoSys: Consultancy, Research Funding; Curis: Research Funding; Bayer: Consultancy, Research Funding; Celgene: Consultancy, Research Funding; Genentech, Inc.: Research Funding; F. Hoffmann-La Roche Ltd: Research Funding.

Background: Mutations in isocitrate dehydrogenase 1 (IDH1) occur in ~3% of individuals with myelodysplastic syndrome (MDS) and have been associated with increased transformation to acute myeloid leukemia (AML). Ivosidenib (AG-120) is an oral, potent, targeted inhibitor of the mutant isocitrate dehydrogenase 1 enzyme (mIDH1) and is approved in the US for the treatment of newly diagnosed AML with a susceptible IDH1 mutation in patients ≥75 years of age or who have comorbidities that preclude the use of intensive induction chemotherapy, and in adult patients with relapsed or refractory (R/R) AML. The first-in-human, phase 1 dose escalation and expansion study of ivosidenib (NCT02074839) enrolled adults with mIDH1 advanced hematologic malignancies, including R/R MDS, and the study is ongoing. In the initial phase of the study (DiNardo et al. N Engl J Med 2018), the 12 patients with R/R MDS received 500 mg ivosidenib once daily and were characterized as follows: 75% were male, median age was 72.5 years (range 52-78), and 42% were ≥75 years of age; median number of prior therapies was 1 (range 1-3). Adverse events (AEs) of any grade, irrespective of causality, occurring in ≥20% of the 12 patients were diarrhea, fatigue, back pain, rash (n=4 each, 33.3%), anemia, urinary tract infection, decreased appetite, hypokalemia, arthralgia, dyspnea, pruritus, and hypotension (n=3 each, 25.0%). No AEs led to permanent discontinuation of treatment. Response was assessed according to International Working Group 2006 criteria for MDS. According to investigators, five of 12 patients achieved complete remission (CR) (41.7%; 95% CI 15.2%, 72.3%); median duration of CR was not estimable for these patients (95% CI 2.8 months, not estimable). Nine of 12 patients were transfusion independent for at least 56 days during study treatment. Mutation clearance was observed in one of the 5 CR patients. Here we report the design of a new sub-study of this trial, which is being undertaken to further assess the safety, tolerability, and clinical activity of treatment with ivosidenib in patients with R/R MDS. Methods: This sub-study is evaluating the safety, tolerability, pharmacokinetics, pharmacodynamics, and clinical activity of ivosidenib. Adults with R/R MDS with an IDH1 mutation will be enrolled in the MDS sub-study. These individuals must have R/R disease after treatment with standard agents indicated for MDS. Eligible patients must have a platelet count of ≥20,000/μL, and adequate hepatic function (total bilirubin ≤1.5 × upper limit of normal [ULN]; aspartate aminotransferase, alanine aminotransferase, and alkaline phosphatase ≤3.0 × ULN) and renal function (serum creatinine ≤2.0 × ULN or creatinine clearance >40 mL/min). Additional key inclusion criteria are bone marrow blasts >5% and/or transfusion dependence. Ivosidenib is to be administered at a dose of 500 mg once daily orally on Days 1 to 28 of 28-day cycles. The addition of the MDS sub-study to this phase 1 clinical study in patients with hematological malignancies will provide additional insights into the use of ivosidenib for the treatment of mIDH1 R/R MDS. Disclosures Foran: Agios: Honoraria, Research Funding. DiNardo:notable labs: Membership on an entity's Board of Directors or advisory committees; medimmune: Honoraria; daiichi sankyo: Honoraria; abbvie: Consultancy, Honoraria; agios: Consultancy, Honoraria; jazz: Honoraria; celgene: Consultancy, Honoraria; syros: Honoraria. Watts:Takeda: Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees; Pfizer: Membership on an entity's Board of Directors or advisory committees; Jazz Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Stein:Agios: Consultancy, Membership on an entity's Board of Directors or advisory committees; Astellas Pharma US, Inc: Membership on an entity's Board of Directors or advisory committees; Celgene Corporation: Membership on an entity's Board of Directors or advisory committees; Daiichi Sankyo, Inc.: Membership on an entity's Board of Directors or advisory committees; Bioline: Membership on an entity's Board of Directors or advisory committees; Genentech: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees; PTC Therapeutics: Membership on an entity's Board of Directors or advisory committees; Syros: Membership on an entity's Board of Directors or advisory committees. De Botton:Daiichi Sankyo: Consultancy; Astellas: Consultancy; Bayer: Consultancy; AbbVie: Consultancy; Syros: Consultancy; Forma: Consultancy, Research Funding; Janssen: Consultancy; Novartis: Consultancy; Pfizer: Consultancy; Servier: Consultancy; Pierre Fabre: Consultancy; Celgene: Consultancy, Speakers Bureau; Agios: Consultancy, Research Funding. Fathi:Amphivena, Kite, Jazz, NewLink Genetics,: Honoraria; Agios, Astellas, Celgene, Daiichi Sankyo, Novartis, Takeda, Amphivena, Kite, Forty Seven,Trovagene, NewLink genetics, Jazz, Abbvie, and PTC Therapeutics: Consultancy. Stein:Stemline: Speakers Bureau; Amgen: Consultancy, Speakers Bureau; Celgene: Speakers Bureau. Stone:AbbVie, Actinium, Agios, Argenx, Arog, Astellas, AstraZeneca, Biolinerx, Celgene, Cornerstone Biopharma, Fujifilm, Jazz Pharmaceuticals, Amgen, Ono, Orsenix, Otsuka, Merck, Novartis, Pfizer, Sumitomo, Trovagene: Consultancy; Argenx, Celgene, Takeda Oncology: Other: Data and Safety Monitoring Board/Committee: ; Novartis, Agios, Arog: Research Funding. Patel:France Foundation: Honoraria; Celgene: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Dava Oncology: Honoraria. Tallman:UpToDate: Patents & Royalties; Daiichi-Sankyo: Consultancy, Membership on an entity's Board of Directors or advisory committees; BioLineRx: Consultancy, Membership on an entity's Board of Directors or advisory committees; Rigel: Consultancy, Membership on an entity's Board of Directors or advisory committees; Jazz Pharmaceuticals: Consultancy, Membership on an entity's Board of Directors or advisory committees; Cellerant: Research Funding; Abbvie: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Delta Fly Pharma: Consultancy, Membership on an entity's Board of Directors or advisory committees; Nohla: Consultancy, Membership on an entity's Board of Directors or advisory committees; ADC Therapeutics: Research Funding; Tetraphase: Consultancy, Membership on an entity's Board of Directors or advisory committees; Orsenix: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Biosight: Research Funding; Oncolyze: Consultancy, Membership on an entity's Board of Directors or advisory committees; KAHR: Consultancy, Membership on an entity's Board of Directors or advisory committees. Choe:Agios: Employment, Equity Ownership; Agios: Employment, Equity Ownership. Wang:Agios: Employment, Equity Ownership. Zhang:Agios: Employment, Equity Ownership; Agios: Employment, Equity Ownership. Fan:Agios: Employment, Equity Ownership. Yen:Agios: Employment, Equity Ownership. Oluyadi:Agios: Employment, Equity Ownership. Winkler:Agios: Employment. Hickman:Agios: Employment, Equity Ownership. Agresta:Agios: Employment, Equity Ownership. Liu:Agios: Employment, Equity Ownership. Wu:Agios: Employment, Equity Ownership. Attar:Aprea Therapeutics: Employment; Agios: Employment, Equity Ownership. Kantarjian:Astex: Research Funding; Takeda: Honoraria; Actinium: Honoraria, Membership on an entity's Board of Directors or advisory committees; Immunogen: Research Funding; AbbVie: Honoraria, Research Funding; Jazz Pharma: Research Funding; Agios: Honoraria, Research Funding; Ariad: Research Funding; Amgen: Honoraria, Research Funding; Cyclacel: Research Funding; BMS: Research Funding; Daiichi-Sankyo: Research Funding; Novartis: Research Funding; Pfizer: Honoraria, Research Funding. OffLabel Disclosure: Ivosidenib (AG-120) is an IDH1 inhibitor indicated for the treatment of AML with a susceptible IDH1 mutation as detected by an FDA-approved test in: 1) adult patients with newly-diagnosed AML who are more than 75 years old or who have comorbidities that preclude use of intensive induction chemotherapy and 2) adult patients with relapsed or refractory AML. It is being evaluated in clinical trials for mutant IDH1 advanced hematologic malignancies.

Introduction: Despite advances in treatment strategy, multiple myeloma (MM) remains a challenging, incurable disease as patients (pts) often relapse. Here we describe preclinical data of a novel cereblon (CRBN) E3 ligase modulatory compound (CELMoD), iberdomide (IBER; CC-220), as well as clinical and translational data from a current phase 1/2 clinical trial (NCT02773030). These data support a differentiated profile for IBER from immunomodulatory agents (IMiD agents), and development of IBER as a foundation of combination therapy for the treatment of relapsed/refractory MM (RRMM). Methods: Preclinical analyses were performed on pomalidomide (POM)-sensitive and acquired-resistant MM cell lines and peripheral blood mononuclear cells from healthy volunteers. Eligible pts enrolled on the clinical trial had RRMM and had received ≥ 2 prior regimens, containing at least an IMiD agent and proteasome inhibitor (PI), and had experienced disease progression within 60 days of last MM therapy. Escalating doses of IBER were given on Days 1-21, in combination with dexamethasone (DEX; 40 mg; 20 mg in pts aged > 75 years) on Days 1, 8, 15, and 22, of each 28-day cycle. Immunohistochemistry (IHC) data on CRBN, Ikaros, Aiolos, and ZFP91 expression was obtained from pt bone marrow specimens at screening and at Cycle 2, Day 15. Immune profiling was evaluated by flow cytometry of peripheral blood at Cycle 1, Day 1 and Cycle 2, Day 15. Primary objectives were to evaluate maximum tolerated dose (MTD), recommended phase 2 dose (RP2D), safety, and preliminary efficacy. Results: Preclinically, IBER exhibited potent tumoricidal anti-MM and immunostimulatory activity. IBER was more potent than lenalidomide (LEN) or POM in overcoming the immunosuppressive activity of bortezomib (BORT), inducing a more than twofold increase in T cell proliferation in the presence of BORT. IBER also enhanced the antibody-dependent cell-mediated cytotoxicity and complement-dependent cytotoxicity of daratumumab (DARA), leading to deeper responses than combinations with LEN or POM. Further differentiating from both LEN and POM, IBER showed activity alone and in combination with BORT or DARA in POM-resistant MM cell lines. As of June 28, 2019, 69 pts with RRMM had received IBER + DEX. Median age was 65 years (range 33-80), and median number of prior regimens was 5 (range 2-12). Prior therapies included autologous stem cell transplantation (80%), LEN (100%), POM (70%), PIs (100%), DARA (71%) and anti-BCMA (6%), including CAR T cells. Clinical activity was observed across all dose levels with an overall response rate (ORR) of 29%, clinical benefit rate of 45%, and disease control rate of 80%. ORR was 30%, 28% and 29% in IMiD agent-refractory, DARA-refractory and Quad-class (IMiD agents/PIs/steroids/CD-38 antibodies)-refractory pts, respectively. IBER + DEX showed a favorable safety profile, with grade 3-4 neutropenia, infections, and thrombocytopenia, occurring in 29%, 25%, and 12% of pts, respectively. To date, IBER doses range from 0.3 to 1.3 mg and the MTD/RP2D has not yet been reached. Pharmacodynamic immunophenotyping changes were dose-dependent. Treatment with IBER (at doses > 0.75mg) + DEX doubled the percentage of proliferating T cells and NK cells (P < 0.001 for each) and increased activated and effector memory CD8+ and CD4+ T cells by > 50% (P < 0.01 for each subset). Pharmacodynamic changes in pt bone marrow by quantitative IHC scoring showed significant degradation of substrates (Ikaros, P = 0.006; Aiolos, P < 0.001; ZFP91, P < 0.001) and downregulation of c-myc (P = 0.027), including in pts refractory to POM and with low CRBN expression. Conclusions: IBER + DEX has shown notable clinical activity and favorable tolerability in heavily pretreated pts with RRMM, including pts refractory to prior IMiD therapy. Preclinical and translational data suggest a differentiated profile of IBER from IMiD agents in regard to activity in POM-resistant models, potency in combination with BORT and DARA, and by inducing changes in CD4+ T cells that were not observed in pts treated with POM from prior studies. Taken together, these data support a differentiated profile for IBER from IMiD agents, and the clinical development of IBER as a foundation of combination therapy for the treatment of RRMM. This study is ongoing, and includes cohorts evaluating the combinations of IBER + DEX with DARA, BORT, and carfilzomib. Updated results will be presented at the meeting. Disclosures Lonial: Karyopharm: Consultancy; GSK: Consultancy; Takeda: Consultancy, Research Funding; Celgene Corporation: Consultancy, Research Funding; Amgen: Consultancy; Genentech: Consultancy; Janssen: Consultancy, Research Funding; BMS: Consultancy. Amatangelo:Celgene Corporation: Employment, Equity Ownership. Popat:Celgene Corporation: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: travel, accommodations, expenses; AbbVie: Consultancy, Membership on an entity's Board of Directors or advisory committees; GSK: Consultancy, Honoraria; Takeda: Honoraria, Other: travel, accommodations, expenses; Janssen: Honoraria, Other: travel support to meetings. Minnema:Gilead: Honoraria; Celgene Corporation: Honoraria, Research Funding; Amgen: Honoraria; Servier: Honoraria; Jansen Cilag: Honoraria. Zonder:Alnylam: Consultancy, Membership on an entity's Board of Directors or advisory committees; BMS: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees; Oncopeptides: Consultancy, Membership on an entity's Board of Directors or advisory committees; Takeda: Membership on an entity's Board of Directors or advisory committees; Amgen: Consultancy, Membership on an entity's Board of Directors or advisory committees; Intellia: Consultancy, Membership on an entity's Board of Directors or advisory committees; Caelum: Consultancy, Membership on an entity's Board of Directors or advisory committees; Celgene Corporation: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Larsen:Janssen Oncology: 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. Oriol Rocafiguera:Celgene Corporation: Consultancy, Speakers Bureau; Janssen: Consultancy; Amgen: Consultancy, Speakers Bureau. Rodriguez Otero:Celgene Corporation: Consultancy, Honoraria, Speakers Bureau; Janssen: Consultancy, Honoraria; Takeda: Consultancy; BMS: Honoraria; Kite Pharma: Consultancy. Badros:Celgene Corporation: Consultancy; Amgen: Consultancy. Siegel:Amgen: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Bristol-Myers Squibb Company: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Takeda: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau. Jagannath:Bristol-Myers Squibb: Consultancy; Janssen Pharmaceuticals: Consultancy; Karyopharm Therapeutics: Consultancy; AbbVie: Consultancy; Merck & Co.: Consultancy; Celgene Corporation: Consultancy. Bringhen:Bristol-Myers Squibb: Honoraria; Celgene Corporation: 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; Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Karyopharm: Membership on an entity's Board of Directors or advisory committees; Takeda: Consultancy. Gironella:Amgen: Honoraria; Janssen: Honoraria; Celgene Corporation: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Kaiser:Takeda, Janssen, Celgene, Amgen: Honoraria, Other: Travel Expenses; Abbvie, Celgene, Takeda, Janssen, Amgen, Abbvie, Karyopharm: Consultancy; Celgene, Janssen: Research Funding. Cook:Janssen, Takeda, Sanofi, Karyopharm, Celgene: Consultancy, Honoraria, Speakers Bureau; Amgen, Bristol-Myers Squib, GlycoMimetics, Seattle Genetics, Sanofi: Honoraria; Celgene, Janssen-Cilag, Takeda: Honoraria, Research Funding. Gamberi:Janssen: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Sanofi: Consultancy, Membership on an entity's Board of Directors or advisory committees; Amgen: Honoraria; Celgene Corporation: Consultancy, Membership on an entity's Board of Directors or advisory committees. Sonneveld:SkylineDx: Research Funding; Takeda: Honoraria, Research Funding; Karyopharm: Honoraria, Research Funding; Janssen: Honoraria, Research Funding; Celgene: Honoraria, Research Funding; BMS: Honoraria; Amgen: Honoraria, Research Funding. Nguyen:Celgene Corporation: Employment, Equity Ownership. Chen:Celgene Corporation: Employment, Equity Ownership. Homan:Celgene Corporation: Employment. Bjorklund:Celgene Corporation: Employment, Equity Ownership. Wang:Celgene Corporation: Employment, Equity Ownership. Pierceall:Celgene Corporation: Employment, Equity Ownership. Bensmaine:Celgene Corporation: Employment, Equity Ownership. Thakurta:Celgene: Employment, Equity Ownership. Peluso:Celgene Corporation: Employment. Van De Donk:Janssen Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene Corporation: Membership on an entity's Board of Directors or advisory committees, Research Funding; Servier: Membership on an entity's Board of Directors or advisory committees; Bristol-Myers Squibb: Membership on an entity's Board of Directors or advisory committees, Research Funding; Takeda: Membership on an entity's Board of Directors or advisory committees; Roche: Membership on an entity's Board of Directors or advisory committees; AMGEN: Membership on an entity's Board of Directors or advisory committees, Research Funding; Bayer: Membership on an entity's Board of Directors or advisory committees.