Abstract: This phase 1/2 trial evaluated combination lenalidomide, bortezomib, pegylated liposomal doxorubicin, and dexamethasone (RVDD) in newly diagnosed multiple myeloma (MM) patients. Patients received RVDD at 4 dose levels, including the maximum tolerated dose (MTD). Patients with a very good partial response or better (≥ VGPR) after cycle 4 proceeded to autologous stem cell transplantation or continued treatment. The primary objectives were MTD evaluation and response to RVDD after 4 and 8 cycles. Seventy-two patients received a median of 4.5 cycles. The MTDs were lenalidomide 25 mg, bortezomib 1.3 mg/m2, pegylated liposomal doxorubicin 30 mg/m2, and dexamethasone 20/10 mg, as established with 3-week cycles. The most common adverse events were fatigue, constipation, sensory neuropathy, and infection; there was no treatment-related mortality. Response rates after 4 and 8 cycles were 96% and 95% partial response or better, 57% and 65% ≥ VGPR, and 29% and 35% complete or near-complete response, respectively. After a median follow-up of 15.5 months, median progression-free survival (PFS) and overall survival (OS) were not reached. The estimated 18-month PFS and OS were 80.8% and 98.6%, respectively. RVDD was generally well tolerated and highly active, warranting further study in newly diagnosed MM patients. This trial was registered at www.clinicaltrials.gov as NCT00724568.

Abstract: Abstract 132 Background: The RVD combination of Lenalidomide (Revlimid®, Len), Bortezomib, (Velcade®, Bz), and Dexamethasone (Dex) and the VDD combination of Bz, pegylated liposomal doxorubicin (Doxil®, PLD), and Dex are among the most active in newly diagnosed multiple myeloma (MM). Pre-clinical studies suggest that combining 4 drugs from RVD and VDD into RVDD may produce even higher activity. The aims of this Phase I/II trial were to determine the maximum tolerated dose (MTD) of the RVDD regimen and to assess its safety and evaluate efficacy in newly diagnosed MM. Methods: Patients (Pts) received Len 15–25 mg (days 1–14), Bz 1.3 mg/m2 (days 1, 4, 8, 11), Dex 20/10 mg (cycles 1–4/5–8; days of and after Bz), PLD 20 or 30 mg/m2 (day 4) at 4 dose levels for up to eight 21-day cycles. In the Phase I portion of the study, pts were assigned to dose levels 1-4 according to the TITE-CRM algorithm. Responses were assessed by modified European Group for Blood and Marrow Transplantation (EBMT) and Uniform Criteria. Pts who achieved at least partial response (PR) could proceed to autologus stem cell transplant (ASCT) after ≥ 4 cycles. After 8 cycles, pts could continue treatment using 21-day maintenance cycles with Len (days 1–14), Bz (day 1 and 8), and Dex (days of and after Bz) at the doses tolerated by the end of initial treatment. Results: The study has enrolled 68 pts to date (median age 61; 52% ISS II/III), 42 pts in phase I (including 6 pts treated at the MTD) and 26 pts in phase II, for a total of 32 of 38 planned pts at the MTD. Pts received a median of 4 cycles (range 1–16); 48 completed at least 4 cycles, 11 completed all 8 cycles, and 34 have discontinued/completed therapy. Seven patients remain on maintenance therapy. Toxicity data are available for 55 pts. In the phase I, 4 pts were assigned to level 1 (Len/PLD 15/20), 11 to level 2 (Len/PLD 20/20, 21 to level 3 (Len/PLD 25/20), and 6 to level 4 (Len/PLD 25/30). Two pts were not evaluable for DLT per protocol criteria and were replaced; 1 at level 2 and 1 at level 3, leaving 40 pts evaluable for DLTs. There were no DLTs at level 1, 2 at level 2, 3 at level 3, consisting of 2 grade (G) 3 asymptomatic neutropenia on day 1 cycle 2, 1 G3 elevation of transaminases, 1 G3 drug fever, and 1 grade 3 hypophosphatemia and none at level 4. Based on the pre-determined definition of maximum tolerated dose (MTD) and probability estimates of DLTs of 4.7% for level 1, 9.7% for level 2, 13.7% for level 3, and 17.9% for level 4, the maximum planned dose level 4 was selected as the MTD for the phase II portion of the study as the closest to, but not exceeding, a target rate of 20% of DLTs. Overall, toxicities have been manageable with G3/4 toxicities in 3–18% of all pts including neutropenia (18%), thrombocytopenia (7%) , infections (16 %) , DVT (2%). There was 4% G3 and no G4 peripheral neuropathy reported, 24% G 1/2 palmar-plantar erythrodysesthesia, and no treatment-related mortality. Response rates in 57 pts evaluable for response were as follows: 96% ≥ PR, 58% ≥ VGPR, and 30% CR/nCR. In 48 pts who completed 4 cycles, defined in the protocol for efficacy assessment, response rates were: 98% ≥ PR, 58% ≥ VGPR and 29% CR/nCR; at MTD ≥PR is 100%. Response rates were not statistically different in a subset of pts (24) with 13q deletion or t(4;14) or t(14;16) or 17p del, with PR, VGPR, and CR/nCR rates 92%, 67%, and 33%, respectively. Twenty four pts proceeded to stem cell collection with 7.5 × 106 CD34+ cells/kg collected after a median of 4 cycles of RVDD (range 3–10). After a median of 6 months of follow-up, median progresssion-free survival and overall survival have not been reached. Conclusion: RVDD is well tolerated in newly diagnosed MM and appears highly active with ≥ PR of 96%, including 58% ≥VGPR, which is unaffected by adverse cytogenetic status. Pts treated at the MTD ,which was determined as Len 25 mg, Bz 1.3 mg/m2, Dex 20 mg, and PLD 30 mg/m2, and completed at least 4 cycles, show 100% ≥PR. Stem cell mobilization and collection was successful in all pts, with unremarkable transplant course reported to date. Updated toxicity and efficacy data will be presented at the meeting. Disclosures: Jakubowiak: Bristol Myers-Squibb: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Exelixis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Centocor OrthoBiotech: Consultancy, Honoraria, Speakers Bureau; Celgene: Consultancy, Honoraria, Speakers Bureau; Millennium: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Off Label Use: Lenalidomide for newly diagnosed multiple myeloma. Reece:Ortho Biotech: Honoraria, Research Funding. Lonial:Novartis: Consultancy; Gloucester: Research Funding; Bristol Myers - Squibb : Consultancy; Millennium: Consultancy, Research Funding; Celgene: Consultancy. Zimmerman:Celgene: Speakers Bureau; Millennium: Speakers Bureau; Centocor: Speakers Bureau. Schlossman:Millennium: Speakers Bureau; Celgene: Speakers Bureau. Laubach:Novartis: Advisory Board. Raje:Celgene, Norvartis, Astrazeneca: Research Funding. Anderson:Millennium: Honoraria, Speakers Bureau; Celgene: Honoraria, Speakers Bureau. Barrickman:Celgene: Employment, Equity Ownership. Tendler:Johnson and Johnson: Employment, Equity Ownership. Esseltine:Johnson and Johnson: Equity Ownership; Milllennium: Employment, Equity Ownership. Kelley:Bristol-Myers Squibb: Equity Ownership. Anderson:Millennium: Consultancy, Honoraria, Research Funding; Novartis: Consultancy, Honoraria, Research Funding; Celgene: Consultancy, Honoraria, Research Funding. Richardson:Bristol Myers-Squibb: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Novartis: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Keryx: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; BMS: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Johnson and Johnson: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau.

Abstract: Abstract 1937 Background: Three-drug combinations with bortezomib (Bz) and/or either thalidomide or lenalidomide (Len) are highly active in frontline MM and appear superior to at least some 2-drug combinations with these agents. In an attempt to further improve treatment outcomes, we developed the 4-drug RVDD regimen of lenalidomide (Revlimid®, Len), Bz (Velcade®), pegylated liposomal doxorubicin (Doxil®, PLD), and dexamethasone (Dex), which demonstrates high activity in newly diagnosed MM. Here we present final results of this Phase I/II trial. Methods: Patients (Pts) received eight 3-week cycles with Len 15–25 mg (days 1–14), Bz 1.3 mg/m2 (days 1, 4, 8, 11), Dex 20/10 mg (cycles 1–4/5-8; days of and after Bz), PLD 20 or 30 mg/m2 (day 4) at 4 dose levels and the maximum tolerated dose (MTD; Phase II). Responses were assessed by modified EBMT and IMWG criteria with the addition of nCR. Pts could proceed to autologous stem cell transplant (ASCT) or continue treatment, which after 8 cycles consisted of 21-day maintenance cycles with Len (days 1–14), Bz (day 1 and 8), and Dex (days of and after Bz) at the doses tolerated by the end of initial treatment. The primary objectives were to evaluate MTD and VGPR rate at the end of 4 and 8 cycles. Results: The study enrolled 72 pts with a median age 60 (range 29–77); 53% ISS II/III; 46% any of the del 13q, t(4;14), t(14;16), or del 17p, of which 37 were treated at the MTD (including 6 in Phase I). Pts received a median of 4.5 cycles (range 2–31); 70 pts completed at least 4 cycles and 20 at least 8 cycles. Five pts developed DLTs, including 2 pts grade (G) 3 asymptomatic neutropenia, 1 G3 elevation of transaminases, 1 G3 drug fever, and 1 G3 hypophosphatemia. Based on the pre-determined definition of MTD, the maximum planned doses of Len 25 mg, Bz 1.3 mg/m2, PLD 30 mg/m2, and Dex 20/10 mg were selected as the maximum tolerated dose (MTD) for the Phase II portion of the study as the closest to, but not exceeding, a target rate of 20% DLTs. The most common toxicities (all grades) were fatigue (83%), infections (72%), constipation (69%), and sensory neuropathy (65%) of which 8%, 14%, 1%, and 6% were G3, respectively. Other G3/4 toxicities included neutropenia (19%), infections (16 %), thrombocytopenia (11%), hyperglycemia (10%), and DVT/PE (3%). There was 25% G1/2 palmar-plantar erythrodysesthesia and 1 pt experienced G1 asymptomatic and reversible decrease in ejection fraction attributed to PLD. Importantly, there was no treatment-related mortality. The best response rates for all pts were as follows: 96% ≥ PR, 66% ≥ VGPR, and 38% CR/nCR. At the end of 4 and 8 cycles, defined in the protocol for efficacy assessment, response rates were: 96% and 95% ≥ PR, 57% and 65% ≥VGPR and 29% and 35% CR/nCR; at the MTD ≥PR was 96%, ≥VGPR 66%, and CR/nCR 34%. Response rates were not statistically different in a subset of pts with any of del 13q, t(4;14), t(14;16), or del 17p. Forty-seven (65%) pts proceeded to ASCT, after collection of a median 6.7 × 106 CD34+ cells/kg (range 1.9–17.7). At 3 months post ASCT, ≥ VGPR and CR/nCR rates improved in 45 evaluable pts from 64% to 84% and from 38% to 60%, respectively. After a median of 15.5 months of follow-up, the estimated 18-month PFS for all pts is 84% and overall survival 99%. Conclusion: RVDD is generally well tolerated and highly active with rapid reduction of MM tumor burden seen (≥ PR 96%, ≥VGPR 57% and CR/nCR rate 29% at the completion of 4 cycles). Response rates further improved after additional treatment, both in pts who continued RVDD treatment (’VGPR 65%, CR/nCR 35%) and pts who proceeded to ASCT (≥VGPR 84%, and CR/nCR 60%), although some additional toxicity was noted. Whether the incorporation of a 4th agent in the form of PLD has made an impact in this pt population remains to be defined. At equivalent time points (i.e. at the completion of 4 and 8 cycles), the ≥VGPR and CR/nCR rates as well as the current estimated PFS appear to compare favorably to RVD, which provides the rationale for consideration of further studies with this regimen, including potential randomized trials in this setting. Disclosures: Jakubowiak: Bristol-Myers Squibb: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Exelixis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Centocor OrthoBiotech: Consultancy, Honoraria, Speakers Bureau; Celgene: Consultancy, Honoraria, Speakers Bureau; Millennium: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees. Off Label Use: Lenalidomide for newly diagnosed multiple myeloma. Reece:Celgene: Unrestricted educational lectures, research funding, ad hoc advisory boards. Lonial:Millennium: Consultancy, Research Funding; Celgene: Consultancy, Research Funding; Novartis: Consultancy, Research Funding; BMS: Consultancy, Speakers Bureau. Zimmerman:Celgene: Speakers Bureau; Millennium: Speakers Bureau. Campagnaro:NIH: Research funding for NIH K12 CA076917. Raje:Celgene: Membership on an entity's Board of Directors or advisory committees; Astra Zeneca: Research Funding; Acetylon: Research Funding. Anderson:Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees; Millennium: Honoraria, Membership on an entity's Board of Directors or advisory committees. Barrickman:Celgene: Employment, Equity Ownership. Tendler:Johnson & Johnson Pharmaceutical Services: Employment, Equity Ownership. Esseltine:Millennium: The Takeda Oncology Company: Employment; Johnson & Johnson: Equity Ownership. Anderson:Millennium: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Onyx: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Acetylon: Equity Ownership. Richardson:Millennium: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees; Johnson & Johnson: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees.

Abstract: Background: FIL (ARRY-520), a specific kinesin spindle protein (KSP) inhibitor, represents a novel class of agent under investigation for the treatment of patients (pts) with MM. Prognosis of pts refractory to immunomodulatory agents (IMiDs) and proteasome inhibitors (PIs) is poor. These pts have a median survival of 9 months underscoring the importance of novel therapeutic strategies incorporating new mechanisms of action. FIL has shown interesting preliminary activity as a single agent as well as in Phase 1 studies in combination with bortezomib (BTZ) and with CFZ, all with a manageable safety profile. Methods: This trial is an ongoing, randomized, multicenter, open-label Phase 2 study for pts with relapsed and refractory MM who received at least 2 prior regimens, including BTZ and an IMiD, and with disease refractory to the last regimen as per IMWG criteria. No prior treatment with CFZ is allowed. Approximately 75 pts will be randomized 2:1 to receive CFZ (20/27 mg/m2 intravenous [IV] on Days 1, 2, 8, 9, 15 and 16) plus FIL (1.25 mg/m2 IV on Days 1, 2, 15 and 16) or single-agent CFZ, at the same dose as in the combination, in a 28-day cycle. Prophylactic filgrastim is administered in the CFZ + FIL arm. The primary endpoint is progression-free survival (PFS). Patients with progressive disease (PD) on CFZ are allowed cross-over to the CFZ + FIL arm if they continue to meet eligibility criteria. Results: As of 15 June 2015, 72 pts have been randomized (23 CFZ, 49 CFZ + FIL) with a median age of 65 years. Pts who could have potentially received ≥ 2 cycles of treatment (20 CFZ, 30 CFZ + FIL) were evaluable for efficacy. These pts were heavily pretreated with a median of 4 and 5 prior regimens in the CFZ and CFZ + FIL arm, respectively. A total of 25% and 30 % of pts, respectively, received prior pomalidomide. The objective response rate (ORR) was 10% in the CFZ arm and 30% in the CFZ + FIL arm. In the CFZ arm, 2 pts achieved a partial response (PR) and 2 pts (10%) achieved an MR. In the CFZ + FIL arm, 3 pts achieved a very good partial response and 6 pts achieved a PR, with 2 additional pts (7%) achieving an MR. In the population of pts who were refractory to both prior BTZ and prior IMiDs, the ORR was 14% and 35%, respectively. Grade 3-4 hematological laboratory abnormalities (≥ 5% of pts) were leukopenia (9% CFZ vs. 21% CFZ + FIL), neutropenia (14% vs. 24%), thrombocytopenia (14% vs. 24%), and anemia (9% vs. 26%). Neutropenia and thrombocytopenia were reversible. No adverse events (AEs) of febrile neutropenia were reported. The only Grade 3-4 non-hematological AE occurring in ≥ 5% of pts was dyspnea (5% vs.11%). The most common reason for treatment discontinuation was confirmed PD (39% vs. 28%) or Investigator discretion in case of unconfirmed PD or clinical PD (17% vs. 12%). Conclusions: The combination of FIL and CFZ was well-tolerated and noticeably increased the ORR compared to CFZ alone in heavily pretreated pts with advanced MM. The preliminary efficacy in pts who are double refractory to IMiDs and BTZ who were randomized to CFZ + FIL appears higher than in pts treated with CFZ alone (in the CFZ arm of this trial and in previously published reports involving such pts). Updated safety and efficacy data, including PFS, will be presented at the meeting. Table. Efficacy evaluable pts (potential to have received ≥ 2 cycles of treatment) CFZ (N = 20) CFZ + FIL (N = 30) Prior regimens, median (range) 4 (2,11) 5 (2,11) N cycles on study, median (range) 4 (1 - 16) 4 (1 - 15+) % ORR (≥ PR) 10 30 % CBR (≥ MR) 20 37 N (%) IMiD & BTZ Refractory 14 (70) 20 (67) % ORR (≥ PR) 14 35 % CBR (≥ MR) 21 40 CBR = clinical benefit rate Disclosures Zonder: Seattle Genetics: Membership on an entity's Board of Directors or advisory committees; Prothena: Membership on an entity's Board of Directors or advisory committees; BMS: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees, Other: research support. Off Label Use: carfilzomib; treatment of myeloma, but not in combination with filanesib. Usmani:Celgene Corporation: Consultancy, Honoraria; Onyx: Consultancy, Honoraria, Research Funding; Janssen: Research Funding. Berdeja:Onyx: Research Funding; Array: Research Funding; Takeda: Research Funding; Acetylon: Research Funding; Janssen: Research Funding; BMS: Research Funding; MEI: Research Funding; Celgene: Research Funding; Novartis: Research Funding; Abbvie: Research Funding; Curis: Research Funding. Anderson:Onyx: Speakers Bureau; Takeda: Speakers Bureau; Celgene: Speakers Bureau. Hari:BMS: Consultancy, Honoraria, Research Funding; Celgene: Consultancy, Honoraria, Research Funding; Janssen: Honoraria; Onyx: Consultancy, Honoraria, Research Funding; Takeda: Consultancy, Honoraria, Research Funding; Sanofi: Honoraria, Research Funding. Singhal:Celgene: Speakers Bureau. Valent:Takeda/Millennium: Speakers Bureau; Celgene: Speakers Bureau. Faber:Celgene: Consultancy. Schiller:Sunesis: Honoraria, Research Funding. Schreiber:Array BioPharma: Employment. Oliver:Array BioPharma: Employment. Rush:Array BioPharma: Employment. Tunquist:Array BioPharma: Employment. Ptaszynski:Array BioPharma: Employment. Raje:Eli Lilly: Research Funding; Millenium: Consultancy; Takeda: Consultancy; Onyx: Consultancy; Acetylon: Research Funding; BMS: Consultancy; AstraZeneca: Research Funding; Novartis: Consultancy; Amgen: Consultancy; Celgene Corporation: Consultancy; Acetylon: Research Funding.

Abstract: Abstract 1024 Background: The MMRC is a non-profit, disease-focused consortium founded in 2004. Sixteen North American member institutions with expertise in multiple myeloma (MM) work collaboratively with the MMRC Inc. (Norwalk, CT) and numerous pharmaceutical partners to speed development of new treatment options to MM patients. In December 2007, MMRC Inc. implemented business solutions to address barriers to rapid activation of phase I-II trials and established benchmarks for initiating and conducting these studies. In December 2010, we reported significantly faster trial start up and accrual data from previous years1,2. Today, we update and expand on MMRC performance data and analysis of progress. Methods: Twenty-five (25) trials conducted within the Consortium from May 2006 to July 2011 had sufficient start up trial data for review. FPFD was defined as the time from the member institutions' receipt of the final protocol (FP) from the trial sponsor, to the time the first patient was dosed on the trial at any participating MMRC member institution. With respect to enrollment, pre-study enrollment commitment (EC) established between MMRC and the study sponsor was defined as the total number of subjects committed to receive at least one dose of study drug across all participating MMRC centers on a trial; baseline enrollment timeline (BET) was prospectively defined as the target time period to attain EC. Results: Mean time to FPFD in the recent group of trials (RG; n=18; Sept 08-Jul 11) held steady at 131 calendar days from receipt of FP as compared to 181 days for the early group of trials (EG; n=7; Jun06-Sept08) representing a 28% reduction in time to FPFD. More importantly, there was a 20% decrease in time to FPFD by all participating MMRC centers on any MMRC trial from 189 days in the RG compared to 236 days in the EG representing an important achievement especially in the Phase I/II arena. MMRC trial accrual data was available for 17/25 trials (2 EG trials were missing data and 6 RG trials continue enrolling). The pre-study mean MMRC EC was 44 subjects per trial (n=19 trials; 849 patients); the mean actual MMRC enrollment was 49 subjects per trial (n=19; 935 patients through July 11) representing a 10% over enrollment versus committed enrollment. A total of 17/19 evaluable trials (89%) met their EC; 12/19 trials met EC within BET (71%) of which 8/12 trials (67%) reached EC 34% faster than their BET (representing a mean reduction of 4.5 months). The overall pre-study mean BET for 19 trials was 13.6 months. MMRC's actual mean enrollment timeline was 12.8 months for the group of 17 evaluable trials representing improvement over the original BET by a mean of 10%. Discussion: MMRC's acceleration of clinical trials provides physicians and patients with rapid access to novel compounds; industry with data for important drug development decisions; and academic institutions with more trials of high scientific interest. Even so, our data uncovered opportunities for improvement. The submission time from receipt of the final protocol from the trial sponsor to Scientific Review Committee (SRC) took an average 30 calendar days across all trials. A reduction to half this time could make a difference to patients and therefore warrants further exploration. Conclusion: Today, drug development in multiple myeloma is fast-paced and highly competitive. MMRC's frequent review of trial metrics provides valuable insight to continually speed answers to physicians, patients and industry. Disclosures: Richardson: Multiple Myeloma Research Consortium: Annual grant in support Clinical Trial Project Management. Vij:Multiple Myeloma Research Consortium: Annual grant in support of clinical trial Project Management. Lonial:Multiple Myeloma Research Consortium: Annual grant in support of clinical trial Project Management. Siegel:Multiple Myeloma Research Consortium: Annual grant in support of clinical trial Project Management. Jakubowiak:Multiple Myeloma Research Consortium: Annual grant in support of clinical trial Project Management. Reece:Multiple Myeloma Research Consortium: Annual grant in support of clinical trial Project Management. Jagannath:Multiple Myeloma Research Consortium: Annual grant in support of clinical trial Project Management. Hofmeister:Multiple Myeloma Research Consortium: Annual grant in support of clinical trial Project Management. Stewart:Multiple Myeloma Research Consortium: Annual Grant in support of clinical trial Project Management. Wolf:Multiple Myeloma Research Consortium: Annual grant in support of clinical trial Project Management. Krishnan:Multiple Myeloma Research Consortium: Annual grant in support of clinical trial Project Management. Zimmerman:Multiple Myeloma Research Consortium: Annual grant in support of clinical trial Project Management. Kumar:Multiple Myeloma Research Consortium: Annual grant in support of clinical trial Project Management. Roy:Multiple Myeloma Research Consortium: Annual grant in support of clinical trial Project Management. Fay:Multiple Myeloma Research Consortium: Annual grant in support of clinical trial Project Management. Anderson:Multiple Myeloma Research Consortium: Annual grant in support of clinical trial Project Management.

Abstract: Background Elotuzumab is an approved monoclonal antibody targeting SLAMF7 on plasma and NK cells that enhances the activity of lenalidomide, pomalidomide, and bortezomib in multiple myeloma (MM). A recent study showed improved outcomes with the combination of pomalidomide, bortezomib, and dexamethasone vs. bortezomib and dexamethasone in relapsed or refractory MM (Richardson PG et al., Lancet Oncol 2019). We therefore studied elotuzumab with pomalidomide, bortezomib, and dexamethasone (elo-PVD) in relapsed and refractory MM. Methods The primary objective was to determine the overall response rate (ORR). Patients with relapsed and refractory disease and ≥1 prior lines of treatment (including lenalidomide and a proteasome inhibitor) were eligible to participate. Prior treatment with pomalidomide was permitted. Elotuzumab was weekly for the first 2 cycles and then every other week. Pomalidomide was given on days 1-21; bortezomib was on days 1, 8, 15; and dexamethasone was weekly. Each cycle was 28 days. Results The trial has completed accrual in September 2018 with 48 patients receiving treatment. The median age was 64 (range 40-80), and median number of prior regimens was 3 (range 1-9); 25% had high risk FISH. All patients had prior lenalidomide and proteasome inhibitor (bortezomib 96%, 29% carfilzomib) and were refractory to their last line of therapy. Other prior therapies included: autologous stem cell transplant (48%), pomalidomide (33%), daratumumab (25%), and isatuximab (4%). 46 patients were assessable for response (2 patients did not complete cycle 1 and were not evaluable for response: 1 due to rapid disease progression; 1 stroke. The median length of follow up was 18.8 months (range 0.5-23.4): 16 patients continue on study; 27 patients discontinued for progressive disease; 3 patients discontinued for adverse events (AEs) (sepsis, pneumonia, stroke); 1 patient underwent auto SCT; and 1 patient was lost to follow up. Best ORR was 61% (PR = 16, VGPR = 10, CR = 2). ORR for patients with prior anti-CD38 antibody, 46%; carfilzomib, 46%; pomalidomide, 43%. Median PFS was 9.8 months (95% CI 6.8-Inf). In patients with 1 prior line of therapy, ORR was 74% and median PFS was not reached (95% CI 12-Inf); 18 month PFS was 68%. Grade ≥ 3 hematologic AEs included anemia (10%), neutropenia (29%), and thrombocytopenia (15%). Additional common grade ≥ 3 AEs included lung infection (27%) and hypophosphatemia (15%). Common non-hematologic AEs all grades included fatigue (grade 1-2 only, 70%), upper respiratory infection (grade 1-2, 56%; grade 3, 2%), diarrhea (grade 1-2 only, 42%), constipation (grade 1-2 only, 35%), hyperglycemia (grade 1-2, 46%; grade 3, 4%), and sensory neuropathy (grade 1-2 only, 31%), with 2 possibly related deaths (sepsis, pneumonia). Conclusions Elo-PVD is one of the first trials of a quadruplet regimen in relapsed and refractory MM incorporating a monoclonal antibody. In patients with refractory disease, elo-PVD shows encouraging responses. With the limitations of cross trial comparisons and small patient numbers, for patients with 1 prior line of treatment and refractory disease, a PFS at 18 months of 68% with elo-PVD compares favorably with a median PFS of 17.8 months in a similar subgroup of PVD in the OPTIMISMM trial (Dimopoulos MA et al., ASH 2018). Patients who received prior pomalidomide, carfilzomib, and/or anti-CD38 monoclonal antibody also benefited. Treatment was well-tolerated with manageable toxicity and with attention to infectious AEs. Disclosures Yee: Celgene: Consultancy, Honoraria, Research Funding; Takeda: Consultancy; Bristol-Myers Squibb: Consultancy, Research Funding; Karyopharm: Consultancy; Adaptive: Consultancy; Amgen: Consultancy, Honoraria. Lipe:Celgene: Consultancy; amgen: Research Funding; amgen: Consultancy. Nadeem:Janssen: Consultancy; Amgen: Consultancy; Celgene: Consultancy; Sanofi: Consultancy. O'Donnell:Celgene: Consultancy; Amgen: Consultancy; BMS: Consultancy; Sanofi: Consultancy; Takeda: Consultancy. Branagan:Pharmacyclics: Consultancy; Janssen: Consultancy; Surface Oncology: Consultancy. Lohr:Celgene: Research Funding; T2 Biosystems: Honoraria. Anderson:Sanofi-Aventis: Other: Advisory Board; Bristol-Myers Squibb: Other: Scientific Founder; Oncopep: Other: Scientific Founder; Amgen: Consultancy, Speakers Bureau; Janssen: Consultancy, Speakers Bureau; Takeda: Consultancy, Speakers Bureau; Celgene: Consultancy, Speakers Bureau. Richardson:Takeda: Membership on an entity's Board of Directors or advisory committees, Research Funding; Amgen: Membership on an entity's Board of Directors or advisory committees; Karyopharm: Membership on an entity's Board of Directors or advisory committees; Bristol-Myers Squibb: Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; Oncopeptides: 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; Sanofi: Membership on an entity's Board of Directors or advisory committees. Raje:Amgen Inc.: Consultancy; Bristol-Myers Squibb: Consultancy; Celgene Corporation: Consultancy; Takeda: Consultancy; Janssen: Consultancy; Merck: Consultancy. OffLabel Disclosure: The combination of elotuzumab, pomalidomide, bortezomib, and dexamethasone is an off-label use in relapsed and refractory multiple myeloma.

Abstract: Abstract 37 The primary objective of CALGB 100104 was to determine if maintenance lenalidomide would prolong time to progression (TTP) after single AHSCT for multiple myeloma. Eligibility included: Stage I-III multiple myeloma, ≤ 1 year from diagnosis, ≥ 2 months of induction with stable disease or better and age 〈 70 years. AHSCT regimen was melphalan 200 mg/m2. Patients (pts) with stable disease or better were randomized double-blinded at day 100–110 post-AHSCT to lenalidomide or placebo, after stratification by diagnostic β2-microglobulin (β2M) level and prior thalidomide or lenalidomide therapy. Starting dose was 10 mg/day, escalated to 15 mg/day after 3 months and continued until disease progression. Drug was stopped and dose reduced according to the development of toxicity. Drug was held for ≥ Gr 3 toxicity, restarted at resolution to ≤ Gr 2 and de-escalated by 5 mg or maintained as tolerated at 15, 10, 5 mg daily or 5 mg daily for 21 of 28 days per month. All pts required some form of anticoagulation including aspirin, warfarin or heparin compounds. There was no consolidation therapy. Results: 568 pts were enrolled before AHSCT (04/15/05-07/03/09) from 47 centers. Of 108 pts (19%) not randomized, reasons were: progressive disease/no response 16%, adverse events (AEs) 5%, died during therapy 2%, refusal 26 %, other disease 1%, other therapy 4 %, other reasons 33%, unknown 14%. Pt characteristics in the lenalidomide arm and placebo arm respectively were: median age (range) 58 (29-70) and 57 (39-70); male gender 48% and 52%; β2M 〉 2.5 mg/L, 28% and 27%. For 554 pts with complete data, induction regimens were thalidomide based (27%), lenalidomide based (22%), bortezomib based (20%), bortezomib and thalidomide based (12%), bortezomib and lenalidomide based (9%), dexamethasone based (4%), lenalidomide and thalidomide (3%), lenalidomide, thalidomide and bortezomib (1%), other (1%) and missing (1%); hence 74% of pts received either lenalidomide or thalidomide prior to enrollment. The primary endpoint of the study, TTP was met in a planned protocol interim analysis in the 3rd quarter of 2009 and the study results were released on 12/17/09. This updated 3rd interim analysis for TTP includes further events up until 12/17/09 after which study pts were un-blinded. This interim analysis is based on 460 randomized pts with approximately 33% of the required number of events (progression or death before progression) observed. The median follow-up is 17.5 months from ASHCT. The number of events among 231 pts randomized to lenalidomide was 44 compared to 91 among 229 pts randomized to placebo. The one-sided unadjusted P-value was 〈 0.0001. Pts receiving lenalidomide experienced a 61% reduction in the risk of disease progression or death when compared to pts receiving placebo. The estimated hazard ratio was 0.39 (95% CI,0.27-0.56 p 〈 0.0001). The preliminary estimated median TTP is 42.3 months for the lenalidomide arm and the estimated median TTP is 21.8 months for the placebo arm. Deaths in the lenalidomide and placebo arms were 19 and 28 respectively (p=0.13) and as of this analysis, there is no difference between these two arms. Significant improvements in TTP were observed in the lenalidomide maintenance arm regardless of β2M level or prior thalidomide or lenalidomide induction therapy. For 389 reported pts, the post-randomization, hematologic AEs were Gr 3 (32%), Gr 4 (13%) and Gr 5 (0) for the lenalidomide arm and Gr 3 (6%) Gr 4 (4%) and Gr 5 (0) for placebo (p=0.0001). The non-hematologic AEs were Gr 3 (30%), Gr 4 (3%) and Gr 5 (1%) for the lenalidomide arm and Gr 3 (19%), Gr 4 (3%), and Gr 5 (2%) for placebo (p=0.0048). Comparing lenalidomide versus placebo post-randomization pooled Gr 3–5 AEs, there were significantly more episodes of thrombocytopenia (11% versus 3%, p=0.01), neutropenia (44% vs 8%, p 〈 0.0001) anemia (5% vs 1%, p=0.0082) and all infections (16% vs 3%, p 〈 0.0001) with lenalidomide. There were no significant differences in incidence of fatigue, neuropathy, rash and thromboembolism. A minority of patients discontinued therapy due to AEs (12%, 28 of 231 on lenalidomide vs 2%, 5 of 229 on placebo) and for other reasons (13%, 29 of 231 on lenalidomide vs 6%, 14 of 231 on placebo). Conclusions: Long term administration of lenalidomide is feasible. When compared to placebo controls, lenalidomide initiated at day 100–110 post-AHSCT in multiple myeloma patients significantly delays TTP. Disclosures: McCarthy: Celgene: Honoraria, Research Funding. Off Label Use: Lenalidomide maintenance therapy for myeloma following autologous hematopoietic cell transplant. Anderson:Millenium: Consultancy, Honoraria; Celgene: Consultancy; Novartis: Consultancy; Onyx: Consultancy; Merck: Consultancy; Bristol Myers Squibb: Consultancy; Acetylon: Equity Ownership, Membership on an entity's Board of Directors or advisory committees. Hurd:Celgene: Research Funding. Giralt:Celgene: Honoraria, Speakers Bureau; Millenium: Honoraria, Speakers Bureau. Stadtmauer:Celgene: Speakers Bureau. Richardson:Celgene: Membership on an entity's Board of Directors or advisory committees; Millenium: Membership on an entity's Board of Directors or advisory committees. Vij:Celgene: Honoraria, Speakers Bureau. Callander:Millenium: Research Funding. Maziarz:Millenium: Speakers Bureau; Genzyme: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau. Landau:Millenium: Membership on an entity's Board of Directors or advisory committees. Martin:Celgene: Speakers Bureau; Millenium: Speakers Bureau; Novartis: Speakers Bureau. Qazilbash:Celgene: Speakers Bureau. Shea:Millenium: Consultancy, Research Funding.

Abstract: Background: The combination of an immunomodulatory drug with the proteasome inhibitor (PI), bortezomib (BORT), and low-dose dexamethasone (LoDEX) has demonstrated preclinical synergy and considerable clinical activity in relapsed and refractory multiple myeloma (RRMM; Mitsiades et al Blood, 2002; Richardson et al Blood, 2014). Treatment (Tx) with the immunomodulatory drug pomalidomide (POM) + LoDEX has been shown to delay disease progression and extend survival in patients (pts) with myeloma previously treated with lenalidomide (LEN) and BORT (Richardson et al Blood, 2014; San Miguel et al Lancet Oncol, 2013). This approach was tested using POM + BORT + LoDEX (PVd) in MM-005; preliminary results showed that PVd was effective and well tolerated in LEN-refractory and BORT-exposed pts. Subcutaneous (SC) BORT was shown to be non-inferior to intravenous (IV) BORT and had an improved safety profile in RRMM (Moreau et al Lancet Oncol, 2011). In addition to a cohort of PVd with IV BORT, MM-005 included a cohort of PVd with SC BORT. Methods: In this phase 1 dose-escalation trial, pts must have received 1-4 lines of prior Tx, with ≥ 2 consecutive cycles of LEN plus a PI. Pts had to be PI exposed and refractory to LEN but not to BORT. A 3 + 3 design with 21-day cycles was used to determine the maximum tolerated dose (MTD). Cycles 1-8 of dose-escalation cohorts received POM (1-4 mg/day on days 1-14), IV or SC BORT (1-1.3 mg/m2 on days 1, 4, 8, and 11), and LoDEX (20 mg/day, or 10 mg/day for pts aged 〉 75 years, on days 1, 2, 4, 5, 8, 9, 11, and 12) until progressive disease (PD) or unacceptable adverse event (AE). After cycle 8, BORT was administered on days 1 and 8, and LoDEX was administered on days 1, 2, 8, and 9. The primary endpoint was MTD, and secondary endpoints included safety, overall response rate (ORR; ≥ partial response [PR]), duration of response (DOR), and time to response. Results: Of the 34 pts enrolled from March 2012 to August 2014, the median age was 58.5 years (range, 36-76 years) and 59% were male. The median number of prior antimyeloma Tx lines (PAMTL) was 2 (range, 1-4), the proportion of pts with ≥ 2 PAMTL was 56%, and the Eastern Cooperative Oncology Group performance status was ≤ 1 for all pts. All pts were refractory to LEN, and all were exposed to prior PI (33 pts [97%] received prior BORT and 2 pts [6%] received prior ixazomib). All pts discontinued Tx, most commonly due to PD (n = 23), but none due to Tx-related AEs. No dose-limiting toxicities were reported in the dose-escalation cohorts or at the maximum planned dose (MPD) of POM 4 mg, BORT 1.3 mg/m2, and LoDEX 20 mg (10 mg for pts aged 〉 75 years). The median number of Tx cycles received was 9 (range, 2-36) for all pts and was 11 (range, 2-19) vs 8 (range, 3-15) in the MPD with IV BORT (n = 10) vs SC BORT (n = 12) cohorts. The ORR for all pts was 65% (n = 22), with 2 complete responses (CRs), 1 stringent CR, 10 very good PRs (VGPRs), and 9 PRs; all pts achieved at least stable disease. The median DOR for the 22 responders was 7.4 months. Commonly reported grade 3/4 AEs were more frequent at the MPD level with IV BORT vs SC BORT (90% vs 75%), including neutropenia (60% vs 17%), thrombocytopenia (40% vs 8%), and pneumonia (30% vs 8%). There were no reports of grade 3/4 peripheral neuropathy (PN) or deep vein thrombosis (DVT) in any of the cohorts. Conclusions: PVd was effective, with an ORR of 65% in pts with LEN-refractory and PI-exposed myeloma. PVd was well tolerated, with no grade 3/4 PN or DVT and no Tx discontinuation due to Tx-related AE; toxicities were well managed. Moreover, AEs were generally less frequent with SC vs IV BORT. Thus, the favorable tolerability and efficacy of PVd, which could be a highly attractive therapeutic option in pts with RRMM, is under further evaluation in the large ongoing phase 3 trial MM-007. Disclosures Richardson: Millennium Takeda: Membership on an entity's Board of Directors or advisory committees; Gentium S.p.A.: Membership on an entity's Board of Directors or advisory committees, Research Funding; Jazz Pharmaceuticals: 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; Celgene Corporation: Membership on an entity's Board of Directors or advisory committees. Off Label Use: Pomalidomide in combination with bortezomib. Raje:BMS: Consultancy; Takeda: Consultancy; Millenium: Consultancy; Novartis: Consultancy; Celgene Corporation: Consultancy; Onyx: Consultancy; Eli Lilly: Research Funding; Amgen: Consultancy; AstraZeneca: Research Funding; Acetylon: Research Funding. Siegel:Celgene Corporation: Consultancy, Speakers Bureau; Amgen: Speakers Bureau; Takeda: Speakers Bureau; Novartis: Speakers Bureau; Merck: Speakers Bureau. Lonial:Janssen: Consultancy, Research Funding; Onyx: Consultancy, Research Funding; Celgene: Consultancy, Research Funding; Novartis: Consultancy, Research Funding; Bristol-Myers Squibb: Consultancy, Research Funding; Millennium: Consultancy, Research Funding. Laubach:Novartis: Research Funding; Millennium: Research Funding; Onyx: Research Funding; Celgene Corporation: Research Funding. Vesole:Celgene Corporation: Speakers Bureau; Idera Pharmaceuticals: Research Funding. Nooka:Spectrum Pharmaceuticals: Consultancy; Onyx: Consultancy. Zaki:Celgene Corporation: Employment, Equity Ownership. Herring:Celgene Corporation: Employment. Li:Celgene Corporation: Employment, Equity Ownership. Shah:Celgene Corporation: Employment, Equity Ownership. Chen:Celgene Corporation: Employment, Equity Ownership. Anderson:Oncocorp: Equity Ownership; Celgene Corporation: Consultancy; acetylon pharmaceuticals: Equity Ownership; Gilead: Consultancy; BMS: Consultancy; Millennium: Consultancy.

Abstract: Introduction: Despite recent advances in the treatment of multiple myeloma, responses may be short-lived and therapeutic resistance develops almost invariably. Non-genetic cellular plasticity and dedifferentiation have recently emerged as a basis for therapeutic resistance in cancer as cells acquire transcriptional states which no longer depend on the drug target. Therefore, a better understanding of plasticity and adaptive state changes in myeloma cells is critical to develop effective therapeutic approaches that can overcome drug resistance. Here we show that cellular plasticity, though frequently invoked as a basis for therapeutic resistance in cancer, can also lead to new therapeutic opportunities. Methods: To define transcriptional states in myeloma at a single cell level, we performed fluorescence activated cell sorting and full-length single-cell RNA sequencing. We assayed a total 6000 CD38+CD138+ plasma cells and CD45+ immune cells from the bone marrow of 8 patients with relapsed and refractory multiple myeloma (RRMM) before and after immuno-modulatory treatment on a clinical trial with elotuzumab, pomalidomide, bortezomib and dexamethasone (Elo-PVD; NCT02718833) and 2 healthy donors. Surface expression of selected markers was validated by flow cytometry. Results: Assessing pre-treatment samples, we discovered that the transcriptional states of single myeloma cells are highly distinct between individual patients, despite the presence of the same established genomic classifiers, such as t(11;14). Furthermore, distinct transcriptional states co-exist within individual patients, indicating there is substantial inter- and intra-individual heterogeneity. Transcriptional states diverge from normal plasma cells towards more immature cells, of the B lymphoid lineage, suggesting a substantial cellular plasticity. Notably, we detected co-expression of myeloid and lymphoid developmental programs in the same single cells. Interestingly, these altered differentiation states were associated with up-regulation of potential immunotherapeutic targets, such as CD20, CD19, and CD33, indicating that this plasticity may result in novel therapeutic vulnerabilities. To define gene-regulatory relationships, we identified a shared core regulatory network present in malignant and normal plasma cells with the active transcription factors XBP1, ATF4, and CREB3, suggesting that myeloma cells retain lineage-specific regulons. However, we further identified patient-specific regulons not detected in any of the mature immune cell populations assayed, such as TEAD4, ELF3 and SNAI1, illustrating an aberrant and promiscuous activation of transcriptional regulators in myeloma cells. Consistent with this finding, we observed an increased number of expressed genes in myeloma cells compared to normal plasma cells as well as an increase in single cell transcriptional entropy, measures that have been linked to cell potency in normal development and cancer. Comparison of pre- and post-treatment samples interestingly revealed a further increase in transcriptional diversity and signatures associated with stemness and developmental potential following treatment. Conclusions: In conclusion, we find that higher transcriptional diversity and activation of alternate gene regulatory programs facilitate the emergence of altered transcriptional states. Interestingly, these altered states are associated with up-regulation of putative immune-therapeutic targets in myeloma cells, thus providing novel therapeutic vulnerabilities. Disclosures Lipe: amgen: Research Funding; Celgene: Consultancy; amgen: Consultancy. O'Donnell:Celgene: Consultancy; Takeda: Consultancy; BMS: Consultancy; Sanofi: Consultancy; Amgen: Consultancy. Munshi:Celgene: Consultancy; Amgen: Consultancy; Oncopep: Consultancy; Janssen: Consultancy; Abbvie: Consultancy; Celgene: Consultancy; Janssen: Consultancy; Takeda: Consultancy; Adaptive: Consultancy; Oncopep: Consultancy; Takeda: Consultancy. Richardson:Karyopharm: Membership on an entity's Board of Directors or advisory committees; Takeda: Membership on an entity's Board of Directors or advisory committees, Research Funding; Bristol-Myers Squibb: Research Funding; Amgen: Membership on an entity's Board of Directors or advisory committees; Janssen: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; Oncopeptides: Membership on an entity's Board of Directors or advisory committees, Research Funding; Sanofi: Membership on an entity's Board of Directors or advisory committees. Anderson:Gilead Sciences: Other: Advisory Board; Janssen: Other: Advisory Board; Sanofi-Aventis: Other: Advisory Board; OncoPep: Other: Scientific founder ; C4 Therapeutics: Other: Scientific founder . Lohr:T2 Biosystems: Honoraria; Celgene: Research Funding. OffLabel Disclosure: Samples for ancillary research were obtained in the context of a phase II clinical trial evaluating Elotuzumab, pomalidomide, bortezomib, dexamethasone The combination of elo-PVD is off label.

Abstract: Abstract 450 Background: New antimyeloma treatments that re-establish tumor response are required to improve survival for pts with advanced, treatment-refractory MM. The MM-002 phase 2 study evaluated the safety and efficacy of oral pomalidomide, in combination with low-dose dexamethasone (POM+LoDex), in pts with relapsed and refractory multiple myeloma (RRMM) who have who have received ≥2 prior therapies including LEN and BORT (Richardson PG, et al. Blood 2011;118:abs 634). Updated results from March 2012 for pts and the outcomes of subgroup analyses are presented. Methods: Eligible pts with MM who had received at least 2 prior therapies (including LEN and BORT) and had disease progression within 60 days of their last treatment were randomized (1:1 ratio) to either POM+LoDEX (POM, 4 mg/day for days 1–21 of a 28-day cycle; LoDex, 40 mg/week) or POM alone. At progression, pts receiving POM alone could receive POM+LoDEX at investigator's discretion. Pts aged over 75 years received LoDex, 20 mg/week. All pts received mandatory thromboprophylaxis (daily low-dose aspirin). Pts were stratified within each treatment group according to age. The key efficacy endpoints included the objective response rate using European Bone Marrow Transplantation (EBMT) criteria, duration of response, progression free survival (PFS) and overall survival (OS), and safety. This updated analysis focused on pts on the POM+LoDex arm. Results: The intention-to-treat efficacy analysis included 113 pts in the POM+LoDex group. The mean age of pts treated with POM+LoDex was 64 years (range, 34–88); 99 pts (88%) were aged ≤75 years. Response rates, median duration of response, and age subgroups are presented in the Table. Median PFS and OS were 4.6 months (mos) and 16.5 mos, respectively, in the POM+LoDex group overall. In the age subgroup analysis of pts treated with POM+LoDex, the median PFS was 4.7 mos in pts aged ≤65 years, and 3.7 mos in pts 〉 65 years. Median OS was 19.7 mos in pts aged ≤65 years and 11.8 mos in pts 〉 65 years. The most common grade 3 or 4 adverse events (AEs) occurring in 〉 5% of pts were neutropenia (41%), anemia (22%), pneumonia (22%), thrombocytopenia (19%), fatigue (14%), dyspnea (13%), leukopenia (10%), back pain (10%), and urinary tract infection (9%). AEs led to at least one dose reduction in 26% of pts; neutropenia was associated with a dose reduction in 4% of pts. Overall, 78% of pts who developed grade 3 or 4 neutropenia used G-CSF during study treatment. There were no reports of grade 3 or 4 peripheral neuropathy (PN); grade 1 or 2 PN occurred in 7% of pts treated with POM+LoDex. Deep vein thrombosis (any grade) occurred in 2 pts (2%), both aged ≤65 years. Grade 3 or 4 neutropenia occurred in 46% of pts aged ≤65 years and in 35% of pts aged 〉 65 years. Despite this, only 1 pt in each age group developed febrile neutropenia (2%). The mean relative dose intensity (dose intensity/planned dose intensity) was 0.9 in both pt groups of ≤65 years and 〉 65 years receiving POM+LoDex. Overall, 21 pts (19%) of the POM+LoDex group died during the study. The most common cause of death was progressive MM (52%; only in 14% of all cases was it due to disease progression); other causes of death (48%) included infections, cerebral/intracranial/subarachonoid hemorrhage, acute respiratory distress syndrome, and suicide in one pt with a history of severe depression. Conclusions: POM, 4 mg/day for days 1–21 of a 28-day cycle in combination with LoDex, is clinically effective and generally well tolerated in pts with RRMM who have received multiple prior treatments including LEN and BORT. POM+LoDex represents an important potential new treatment option for pts with advanced MM and appears active in both younger and older pts, with tolerability similar across different age groups. Phase 3 studies of POM+LoDEX in combination with other agents (e.g. bortezomib) are ongoing. Disclosures: Jagannath: Millennium Pharma: Honoraria, Membership on an entity's Board of Directors or advisory committees; Merck Sharp & Dohme: Honoraria, Membership on an entity's Board of Directors or advisory committees; Onyx Pharma: 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. Off Label Use: Pomalidomide is an investigational drug and is not approved for the treatment of patients with any condition. Hofmeister:Celgene: Advisory Board Other, Honoraria. Siegel:Onyx: Advisory Board, Advisory Board Other, Honoraria, Speakers Bureau; Millennium Pharma: Advisory Board, Advisory Board Other, Honoraria, Speakers Bureau; Celgene: Advisory Board Other, Honoraria, Speakers Bureau; Merck: Advisory Board, Advisory Board Other, Honoraria, Speakers Bureau. Vij:Onyx: Consultancy, Research Funding; Millennium Pharma: Speakers Bureau; Celgene: Consultancy, Research Funding, Speakers Bureau. Lonial:Millennium, Celgene, Novartis, BMS, Onyx, Merck; all 〈 $10,000 per year and disclosed to my institution: Consultancy. Anderson:Acetylon, Oncopep: Scientific Founder, Scientific Founder Other; Celgene, Millennium, BMS, Onyx: Membership on an entity's Board of Directors or advisory committees. Chen:Celgene: Employment, Equity Ownership. Zaki:Celgene: Employment, Equity Ownership. Richardson:Celgene, Millennium, Johnson & Johnson: Advisory Board Other.