Citations

Abstract Background : Carfilzomib is an innovative second generation proteasome inhibitor (PI) that binds irreversibly and selectively to the proteasome. Carfilzomib exhibits sustained inhibition of the proteasome with minimal off-target activity. Kd was approved in 2016 as a treatment (Tx) option for R/RMM patients who have received one to three prior lines of therapy.In the ENDEAVOR phase 3, open label, multicenter randomized controlled trial assessing Kd vs Vd, median progression-free survival (PFS) was 18.7 months (95% CI:15.6 - could not be estimated) in the Kd group vs 9.4 months (8.4 - 10.4) in the Vd group at an a priori, pre-specified interim analysis (hazard ratio [HR]: 0.53 [95% CI: 0.44 - 0.65]; p<0.0001). OS data at the 1st interim analysis were immature. In the current study, we assessed the cost-effectiveness (CE) of Kd vs Vd from a US payer perspective using data from ENDEAVOR and long-term overall survival (OS) data from the Surveillance, Epidemiology, and End Results Program (SEER). Methods: A partitioned-survival model with a progression-free (PF), a post-progression (PP) and a death state was built with a 30 year horizon. PFS was modelled using separately fitted log-logistic parametric curves. In order to estimate measures of efficacy for OS and to incorporate treatment effect into the model, time-dependent multiple semiparametric Cox regression analyses were implemented for OS outcomes, which controlled for baseline covariates. OS for Vd in the base case was modelled with a separately fitted Weibull parametric curve, which was fitted to the Vd data. The time-dependent multiple Cox model generated a HR for 0 to 12 months and a HR beyond 12 months for Kd vs Vd, which were applied to model the Kd OS curve. The OS curves beyond 36 months were extrapolated with SEER data. A Weibull distribution was used for the extrapolation by matching the SEER registry data to the ENDEAVOR population, which was assumed to represent the Vd survival rate. To this extrapolated survival curve beyond 36 months, the OS treatment effect was applied in order to model the Kd curve. Grade ≥ 3 adverse events (AEs) with ≥ 2% incidence in any ENDEAVOR arm were included. Utilities were derived from the literature and adjusted for the treatment specific improvement in QoL observed when patients were PF in ENDEAVOR. Costs related to drug (WAC prices), administration, monitoring, AE management, and subsequent Tx were considered. The base case utilized OS results from an updated OS dataset (March 2016) that resulted in an ad hoc OS analysis. A 3% discount rate was applied to costs and health outcomes. Results: In the base-case, results from the model showed thatKd was more effective compared to Vd, providing 1.874 PfLY, 1.854 LY, and 1.654 QALY gains over the modelled horizon. Kd incurred $227,703 in total additional costs and the ICER vs Vd was 137,660$/QALY. Conclusions: The model predicts that Kd delivers 1.85 additional life years over the the comparator Vd. Per the base case, Kd is cost-effective vs Vd at generally accepted willingness-to-pay thresholds of $150,000/QALY and $300,000/QALY in the US. Based on the ENDEAVOR data, Kd is a superior PI-based doublet compared to Vd, and should be preferred whenever doublets are appropriate for the patient, Furthermore, this CE analysis shows that Kd delivers considerable incremental value to patients with relapsed or refractory MM and to payers who must allocate budgets for the treatment of patients. Table Table. Disclosures Jakubowiak: Takeda: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Amgen Inc.: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Karyopharm: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; SkylineDx: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Sanofi: Consultancy, Honoraria, 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; Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees. Majer:Amgen Inc: Employment, Equity Ownership. Houisse:Amgen Inc: Consultancy. Benedict:Amgen Inc: Consultancy. Campioni:Amgen: Employment, Other: Holds Amgen Stock. Panjabi:Amgen Inc: Employment, Equity Ownership. Ailawadhi:Pharmacyclics: Consultancy; Novartis: Consultancy; Amgen Inc: Consultancy; Takeda Oncology: Consultancy.

Abstract Introduction: Venetoclax (Ven), an oral agent that targets the antiapoptotic protein, BCL-2, has demonstrated efficacy, as monotherapy and combined with proteasome inhibitor (PI) bortezomib, in relapsed/refractory (R/R) multiple myeloma (MM). We report preliminary safety and efficacy data for Ven combined with the second generation PI carfilzomib (K) and dexamethasone (VenKd) in R/R MM. Methods: In this ongoing phase 2, dose escalation study (NCT02899052), patients with R/R MM and no prior K exposure received VenKd on 28-d cycles in 4 dose finding and one expansion cohorts: Ven 400 mg/day + K 27 mg/m2 Day 1, 2, 8, 9, 15, 16 + dex 40 mg Day 1, 8, 15, 22 (Cohort 1), same regimen but with Ven 800 mg/day (Cohort 2), Ven 800 mg/day + K 70 mg/m2 Day 1, 8, 15 + dex 40 mg Day 1, 8, 15, 22 (Cohort 3/expansion cohort), or Ven 800 mg + K 56 mg/m2 Day 1, 2, 8, 9, 15, 16 + dex 40 mg Day 1, 2, 8, 9, 15, 16, 22, 23 (Cohort 4). Treatment continued until progressive disease (PD) or unacceptable toxicity. Results: As of June 11, 2018, 42 patients were enrolled. The median age was 66.5 years (min, max: 37, 79), 63% had ISS II/III disease, and 8 patients (19%) had t(11;14). Patients received a median of 2 prior therapies (range: 1 - 3), 93% had received prior PI (50% refractory), 62% were refractory to immunomodulatory therapies, and 33% double refractory. At the data cut off, 29 patients were still active and had completed ≥2 cycles and 13 patients discontinued with the primary reason being disease progression (n=4), death (n=3), physician decision (n=2), withdrawal of consent (n=2), lack of efficacy (n=1), and AE (n=1). All patients experienced at least one AE, and grade 3/4 AEs experienced by >10% of subjects included: decreased lymphocyte count (26%), decreased neutrophil count (14%), and hypertension (12%). Thirteen subjects experienced at least one serious AE. Maximum tolerated dose was not reached and Ven 800 mg/day + K 70 mg/m2 was selected for expansion. Ven mean (% coefficient of variation) maximum plasma concentration (Cmax) and area under the plasma concentration-time curve over 24 hours (AUC24) on Cycle 1 Day 15 were 2.7 (57) mg/mL and 33.1 (54) mg×h/mL, respectively, at 400 mg venetoclax (n=4); and were 2.42 (53) mg/mL and 38.7 (51) mg×h/mL, respectively, at 800 mg venetoclax (n=13) in the dose escalation cohorts. The overall response rate (ORR) was 78% and the very good partial response (VGPR) or better rate was 56% (Table). Median time from first dose to the data cut or discontinuation was 5.7 months (range: 0.9 - 16.3) and the median time to first response was 1.9 months (95% CI: 0.9, 9.2). ORRs for subgroups of interest are reported in the Table. Conclusions: The combination of VenKd appears tolerable with no new safety signals or changes in Ven pharmacokinetics. VenKd shows promising preliminary efficacy in R/R MM patient subgroups. Response rates were comparable in all high risk subgroups and overall population. However, the subset of patients with t(11;14) had the highest response. Overall, these results demonstrate that VenKd is a safe and efficacious regimen in R/R MM and support the continued study of VenKd. Disclosures Costa: Abbvie: Research Funding; BMS: Research Funding; Karyopharm: Research Funding; Amgen: Honoraria, Research Funding; Sanofi: Honoraria; Celgene: Honoraria, Research Funding; Janssen: Research Funding. Stadtmauer:Celgene: Consultancy; AbbVie, Inc: Research Funding; Janssen: Consultancy; Takeda: Consultancy; Amgen: Consultancy. Morgan:Bristol-Myers Squibb: Consultancy, Honoraria; Janssen: Research Funding; Takeda: Consultancy, Honoraria; Celgene: Consultancy, Honoraria, Research Funding. Kovacsovics:Amgen: Honoraria, Research Funding; Abbvie: Research Funding. Jakubowiak:Takeda: Consultancy, Honoraria; Amgen: Consultancy, Honoraria; Janssen: Consultancy, Honoraria; Bristol-Myers Squibb: Consultancy, Honoraria; SkylineDx: Consultancy, Honoraria; Adaptive Biotechnologies: Consultancy, Honoraria; AbbVie: Consultancy, Honoraria; Karyopharm: Consultancy, Honoraria; Celgene: Consultancy, Honoraria. Kaufman:Roche: Consultancy; BMS: Consultancy; Karyopharm: Other: data monitoring committee; Janssen: Consultancy; Abbvie: Consultancy. Mobasher:Genentech Inc: Employment; F. Hoffmann-La Roche Ltd: Other: Ownership interests non-PLC. Freise:AbbVie, Inc: Employment, Equity Ownership. Ross:AbbVie, Inc: Employment, Equity Ownership. Pesko:AbbVie, Inc: Employment, Equity Ownership. Munasinghe:AbbVie, Inc: Employment, Equity Ownership. Gudipati:AbbVie, Inc: Employment, Equity Ownership. Mudd:AbbVie, Inc: Employment, Equity Ownership. Bueno:AbbVie, Inc: Employment, Equity Ownership. Kumar:Oncopeptides: Membership on an entity's Board of Directors or advisory committees; Takeda: Membership on an entity's Board of Directors or advisory committees; AbbVie: Membership on an entity's Board of Directors or advisory committees, Research Funding; Roche: Research Funding; Merck: Membership on an entity's Board of Directors or advisory committees, Research Funding; KITE: 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; Novartis: Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; KITE: Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: 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; AbbVie: Membership on an entity's Board of Directors or advisory committees, Research Funding.

Abstract Abstract 813FN2 Introduction: Carfilzomib is a next-generation proteasome inhibitor that selectively and irreversibly binds to its target, resulting in sustained inhibition absent of off-target effects relative to bortezomib. Carfilzomib has demonstrated durable anti-tumor activity and an acceptable tolerability profile in patients with multiple myeloma (MM). Final results will be presented for the bortezomib-naïve group of PX-171-004, a phase 2 study of single-agent carfilzomib in patients with relapsed and/or refractory MM. Herein we report the most recent data analysis available at time of abstract submission. Updated final results for the bortezomib-naïve group of PX-171-004, including OS data, will be presented at the meeting. Methods: Patients received either 20 mg/m2 for all treatment cycles (Cohort 1) or a stepped-up dose-escalating regimen of 20 mg/m2 for Cycle 1 and 27 mg/m2 for all treatment cycles thereafter (Cohort 2). Carfilzomib was administered over 2–10 minutes on Days 1, 2, 8, 9, 15, and 16 of every 28-day cycle, for a maximum of 12 cycles. The primary endpoint was the best overall response rate (ORR; [CR + VGPR + PR]) determined according to the IMWG Uniform Response Criteria. Secondary endpoints included the clinical benefit response rate (CBR; [ORR + MR per EBMT criteria]), progression-free survival (PFS), time to progression (TTP), duration of response (DOR), OS, and safety. The result of efficacy analysis from disease assessment by the Independent Review Committee is presented in this abstract. Results: 127 of 129 enrolled bortezomib-naïve patients were evaluable for response. Prior therapies included thalidomide (59%), lenalidomide (59%), alkylating agents (81%), and stem cell transplant (73%). Patients had received a median of 2 prior regimens (1 in 54 patients, 2 in 40 patients, 3 in 28 patients, and ≥4 in 7 patients). 84 patients (65%) were disease refractory to their most recent therapy, defined as ≤25% response or progression during or within 60 days after completion of therapy. The median duration of carfilzomib treatment is 7 cycles (range 1−12) in Cohort 1; 8 patients were receiving drug as of February 2011 in Cohort 2 with a median treatment of 6.5 cycles (range 1−13) at that time. Best ORR was 42% in Cohort 1 and 52% in Cohort 2. Median TTP was 8.3 months and median DOR was 13.1 months in Cohort 1. The median TTP and DOR for Cohort 2 have not been reached at the time of this interim analysis; the lower bound of the 95% CI for the median TTP was 10.2 months, and 84% were estimated to have DOR ≥1 year at the time of data cutoff. Higher response rates for Cohort 2 compared with Cohort 1 do not appear to be associated with higher toxicities. Patients with unfavorable cytogenetic characteristics (≥1 abnormality) per mSMART criteria had an ORR of 37% and CBR of 42% compared with 50% and 65%, respectively, for patients with no abnormality. The most common treatment-emergent adverse events (AEs), regardless of relationship to carfilzomib in Cohorts 1 and 2, respectively, were fatigue (71%, 54%), nausea (54%, 43%), anemia (46%, 37%), and dyspnea (49%, 33%). These were primarily ≤Grade 2 in severity. The most common Grade 3/4 AEs were anemia (15%), lymphopenia (15%), thrombocytopenia (13%), pneumonia (12%) and neutropenia (12%). Treatment-emergent peripheral neuropathy (PN) was mild and infrequent (16%). Only 1 case of Grade 3 PN (0.8%) was observed. Overall, 38 patients (30%) completed 12 cycles and 22 of these patients continued to receive carfilzomib therapy under a safety extension protocol (PX-171-010), an ongoing, multicenter, open-label phase 2 study to monitor long-term use of single-agent carfilzomib. Conclusions: To date we have seen robust and durable single-agent activity for carfilzomib in bortezomib-naïve patients with relapsed and often refractory MM with an ORR of 42−52% and a CBR of 59−63% from 2 separate dose cohorts in a population wherein 92% received an immunomodulatry drug and 73% had undergone an autologous stem cell transplant previously. These data are suggestive of a dose–response relationship and are being further evaluated in the exploratory phase 1b/2 study PX-171-007. Carfilzomib was associated with minimal PN and excellent long-term tolerability, with nearly one-third of patients completing 12 cycles and 22 of these continuing treatment beyond 1 year in the extension protocol PX-171-010. Disclosures: Vij: Onyx Pharmaceuticals: Consultancy, Research Funding; Celgene: Research Funding, Speakers Bureau; Millennium: Speakers Bureau. Kaufman:Millenium: Consultancy; Onyx Pharmaceuticals: Consultancy; Novartis: Consultancy; Keryx: Consultancy; Merck: Research Funding; Celgene: Research Funding. Jakubowiak:Ortho Biotech: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Celgene: Consultancy, Honoraria, Speakers Bureau; Millennium Pharmaceuticals, Inc.: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Onyx Pharmaceuticals: Consultancy, Membership on an entity's Board of Directors or advisory committees; Bristol-Myers Squibb: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Exelixis: Consultancy, Honoraria. Wang:Onyx Pharmaceuticals: Research Funding. Jagannath:Millennium: Honoraria; Celgene: Honoraria; Onyx Pharmaceuticals: Honoraria; Merck: Honoraria; OrthoBiotec.Imedex: Membership on an entity's Board of Directors or advisory committees; Medicom World Wide: Membership on an entity's Board of Directors or advisory committees; Optum Health Education: Membership on an entity's Board of Directors or advisory committees; PER Group: Membership on an entity's Board of Directors or advisory committees. Kukreti:Celgene: Honoraria. Alsina:Millennium: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees; Allergan: Research Funding. Belch:Celgene: Research Funding; Onyx: Research Funding. Gabrail:Millennium: Research Funding. Matous:Celgene: Speakers Bureau; Millenium: Speakers Bureau; Cephalon: Speakers Bureau. Vesole:Celgene: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Millennium: Speakers Bureau. Orlowski:Onyx Pharmaceuticals: Honoraria, Membership on an entity's Board of Directors or advisory committees. Kunkel:VLST biothech: Consultancy; Threshold: Consultancy; Onyx Pharmaceuticals: Consultancy. Wong:Onyx Pharmaceuticals: Employment, Equity Ownership. Stewart:Celgene: Consultancy, Research Funding; Millennium: Consultancy, Research Funding; Novartis: Consultancy, Research Funding; BMS: Consultancy, Research Funding; Onyx Pharmaceuticals: Consultancy, Research Funding.

Abstract Background LGH447 is a novel, specific pan-Pim kinase inhibitor in development for the treatment of patients with multiple myeloma (MM) and other hematologic malignancies. The PIM kinase gene family encodes 3 serine/threonine protein kinases that have roles in cell cycle progression and survival. In human disease, elevated levels of Pim1 and Pim2 are associated with hematologic malignancies, with MM showing the highest level of Pim2 expression. In preclinical studies, a majority of MM cell lines proved sensitive in vitro to LGH447-mediated Pim inhibition, exhibiting a dose-dependent decrease in cell proliferation. Furthermore, LGH447 was well tolerated and demonstrated significant inhibition of tumor growth in xenograft mouse models of MM as compared with control animals, supporting the clinical development of LGH447 in MM patients. Methods Patients with relapsed/refractory MM for whom no effective treatment options exist were enrolled on this first-in-human, multicenter, open-label phase 1 dose-escalation study (CLGH447X2101). Escalating doses of single-agent LGH447 were administered orally on a continuous daily dosing schedule. Treatment continued until disease progression, unacceptable toxicity, consent withdrawal, or death. The primary objective was to estimate the maximum tolerated dose (MTD) of LGH447 administered as a single agent, orally, once daily. Secondary objectives included assessing the safety, tolerability, preliminary antimyeloma activity, and pharmacokinetic (PK) profiles of LGH447. Dose escalation followed a Bayesian logistic regression model based on dose-limiting toxicities (DLTs) occurring in cycle 1. Adverse events (AEs) were graded according to National Cancer Institute-Common Terminology Criteria for Adverse Events v4.03. Efficacy assessments were made by investigators according to International Myeloma Working Group (IMWG) uniform response criteria with modifications. Following determination of the MTD for LGH447, additional patients will be enrolled in an expansion cohort to further characterize the safety and tolerability profile of LGH447. Results At the data cutoff, 19 patients have been treated at the following doses: 70 mg (n = 5), 150 mg (n = 6), 200 mg (n = 4), 250 mg (n = 4), with enrollment ongoing in dose escalation. Median age was 66 years (range, 41-75 years). Most patients (94.7%) presented with baseline Eastern Cooperative Oncology Group performance status 0-1. Most patients (73.7%) had received ≥ 2 prior regimens (median 4; range, 1-11), 89.5% had received prior bortezomib, and 84.2% had received prior lenalidomide and/or thalidomide (68.4% and 47.4%, respectively). Ten patients are ongoing at doses between 150-250 mg, with a median duration of exposure of 6 weeks (range, 1-26.6 weeks), and 9 patients discontinued (disease progression [n = 6], AEs [n = 2], withdrawal of consent [n = 1]). There was 1 DLT consisting of grade 3 thrombocytopenia at the 200 mg dose level and no reported suspected unexpected serious AEs. The majority of AEs regardless of study drug relationship were grade 1/2. Most common grade 3/4 AEs were thrombocytopenia (31.6%), anemia (21.1%), and neutropenia (15.8%). No deaths have occurred on study. LGH447 displayed time-dependent PK with a 3- to 6-fold accumulation from day 1 to steady state (day 14). After a single oral dose, area under the curve and maximum concentration increased somewhat more than in proportion to the dose from 70 to 250 mg. Evidence of single-agent activity, as determined by investigators using IMWG criteria, has been seen in multiple patients, with best response to date being a very good partial response (VGPR). Conclusion In heavily treated patients with relapsed/refractory MM, LGH447 was generally well tolerated and exhibited evidence of single-agent efficacy in multiple patients, validating Pim kinase inhibition as a promising therapeutic rationale and supporting its further clinical development in patients with MM and other hematologic malignancies. Dose escalation is ongoing and updated results will be presented. Disclosures: Ocio: BMS: Consultancy; Arry-520: Consultancy; Pharmamar: Research Funding; Celgene: Honoraria, Research Funding; Onyx: Consultancy, Research Funding; Novartis: Honoraria. Thomas:Novartis: Research Funding; Celgene: Research Funding; Immunomedics: Research Funding; Pharmacyclics: Membership on an entity’s Board of Directors or advisory committees; Onyx: Membership on an entity’s Board of Directors or advisory committees; Millenium: Research Funding. Günther:Novartis: Consultancy, Research Funding. Lebovic:Celgene: Speakers Bureau; Allos/Spectrum: Speakers Bureau; Genentech: Speakers Bureau; Onyx: Speakers Bureau. Kumar:Onyx: Consultancy, Research Funding; Millennium: Consultancy, Research Funding; Celgene: Consultancy, Research Funding. Jakubowiak:Onyx: Consultancy, Honoraria, Speakers Bureau; Millennium: Consultancy, Honoraria; Celgene: Consultancy, Honoraria, Speakers Bureau; BMS: Consultancy, Honoraria. Song:Novartis: Employment. Xiang:Novartis: Employment. Hynds:Novartis: Employment. Vanasse:Novartis: Employment. Goh:Jannsen: Research Funding; BMS: Membership on an entity’s Board of Directors or advisory committees; Gilead: Honoraria, Membership on an entity’s Board of Directors or advisory committees; Hospira: Honoraria, Membership on an entity’s Board of Directors or advisory committees; Novartis: Honoraria, Membership on an entity’s Board of Directors or advisory committees, 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 Introduction Multiple Myeloma is not a single disease. There is increasing support for risk classification in combination with treatment decision making because of its impact on clinical outcomes. Here we demonstrate additional evidence of the prognostic value of SKY92, an established genetic marker of high risk Multiple Myeloma in a multicenter collection of samples with undisclosed treatments. Materials Methods A public GEP dataset (MMRC, MMGI portal) contained 114 cases of untreated Multiple Myeloma and was used for SKY92 high risk OS prediction (Kuiper et al. Leukemia 2012). In collaboration with MMRC, OS (with a minimum of at least 2 year follow-up) was collected for 91 of 114 cases for the purpose of this analysis. Briefly, CD138-positive plasma cells had been purified prior to total RNA extraction and subsequent gene expression profiling on Affymetrix U133Plus2.0 GeneChips. The 91 cases represented 9 different clinical sites and their CEL files were normalized as a single batch against a reference cohort of 329 cases after which the SKY92 risk scores were determined as either standard risk or high risk. Results SKY92 resulted in 19 high risk (20.9%) versus 72 standard risk (79.1%) cases in the unselected 91 case-cohort. Comparisons with other high risk GEP signatures will be performed. The OS analysis (Figure 1) shows that the HR cases have significantly shorter survival (Hazard Ratio 11, p = 7 x 10-5). Table 1 shows that high risk patients had more elevated B2M (26.3% vs 13.9%), more low albumin (26.3% vs 16.7%) and more high creatinine (26.3% vs 11.0%). There was no difference between high and standard groups in diagnosis dates (not shown). Cause of the 16 (84.2%) deaths among the high risk cases, and 21 (29.1%) deaths among the standard risk cases indicates that high risk contains less disease progression deaths (57.1% vs 31.3%), and more unknown deaths (56.3% vs 23.8%). Conclusions The SKY92 classifier identified 19 of 91 cases (21%) as high risk, recapitulating the percentage of high risk in previously studied cohorts (Kuiper et al. 2012). Moreover the hazard ratio of 11 when events up to 24 months or 8.18 when all events are considered, emphasizes the unmet medical need of high risk cases identified with SKY92 as 69% of all deaths within 2 years (9/13 death events) were in this category. Acknowledgments This research was performed within the framework of CTMM, the Center for Translational Molecular Medicine, project BioCHIP grant 03O-102. Rafael Fonseca is a Clinical Investigator of the Damon Runyon Cancer Research Fund. This work is supported by grants R01 CA83724, ECOG CA 21115T, Predolin Foundation, Mayo Clinic Cancer Center and the Mayo Foundation. Disclosures: van Beers: Skyline Diagnostics: Employment. Van Vliet:Skyline Diagnostics: Employment. Anderson:celgene: Consultancy; onyx: Consultancy; gilead: Consultancy; sanofi aventis: Consultancy; oncopep: Equity Ownership; acetylon: Equity Ownership. Jagannath:Celgene: Honoraria; Millennium: Honoraria. Jakubowiak:BMS: Consultancy, Membership on an entity’s Board of Directors or advisory committees; Celgene: Consultancy, Honoraria, Membership on an entity’s Board of Directors or advisory committees, Speakers Bureau; Millennium: Consultancy, 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, Speakers Bureau. Kumar:Celgene: Clinical Trial Support Other, Membership on an entity’s Board of Directors or advisory committees; Cephalon: Clinical Trial Support, Clinical Trial Support Other; Millennium: Clinical Trial Support, Clinical Trial Support Other, Membership on an entity’s Board of Directors or advisory committees; Novartis: Clinical Trial Support, Clinical Trial Support Other; Onyx: Clinical Trial Support Other, Membership on an entity’s Board of Directors or advisory committees. Lebovic:Celgene: Speakers Bureau; Onyx: Speakers Bureau. Lonial:Millennium: Consultancy; Celgene: Consultancy; Novartis: Consultancy; BMS: Consultancy; Sanofi: Consultancy; Onyx: Consultancy. Reece:Onyx: Honoraria; Novartis: Honoraria; Millennium: Research Funding; Merck: Honoraria, Research Funding; Janssen: Honoraria, Research Funding; Celgene: Honoraria, Research Funding; BMS: Research Funding. Siegel:Celgene: Membership on an entity’s Board of Directors or advisory committees, Speakers Bureau; Millennium: Membership on an entity’s Board of Directors or advisory committees, Speakers Bureau; Onyx: Membership on an entity’s Board of Directors or advisory committees, Speakers Bureau. Vij:Celgene: Honoraria, Research Funding, Speakers Bureau; Millennium: Honoraria, Speakers Bureau; Onyx: Honoraria, Research Funding, Speakers Bureau. Zimmerman:Celgene: Honoraria; Millennium: Honoraria; Onyx: Honoraria. Fonseca:Medtronic: Consultancy; Otsuka: Consultancy; Celgene: Consultancy; Genzyme: Consultancy; BMS: Consultancy; Lilly: Consultancy; Onyx: Consultancy, Research Funding; Binding Site: Consultancy; Millennium: Consultancy; AMGEN: Consultancy; Cylene: Research Funding; Prognostication of MM based on genetic categorization of the disease: Prognostication of MM based on genetic categorization of the disease, Prognostication of MM based on genetic categorization of the disease Patents & Royalties.

Abstract Background: Carfilzomib (CFZ) is a novel proteasome inhibitor of the epoxyketone class that exhibits a high level of selectivity for the proteasome and has been shown in a phase 1 study to result in greater than 80% proteasome inhibition on a QDx2 consecutive day schedule. We piloted this agent in MM patients with relapsed and refractory disease, who had failed bortezomib (BTZ) and at least one immunomodulatory (IMiD) agent, e.g., thalidomide (THAL) and/or lenalidomide (LEN). Methods: PX-171-003 is an open-label, multicenter study enrolling pts with MM who have relapsed from at least 2 prior therapies and who are refractory; defined as progressing on or within 60 days of last therapy or<25% response to the last therapy. Pts received CFZ 20 mg/m2 IV Days 1, 2, 8, 9, 15 and 16 every 28 days, for up to 12 cycles. Dexamethasone 4 mg po was administered prior to each dose in Cycle 1. Responses were evaluated by the International Uniform Response Criteria for Multiple Myeloma. Clinical benefit response (CBR) was defined as complete response (CR) + partial/very good partial response (PR/VGPR) + minimal response (MR, as defined by EBMT criteria). Responses were adjudicated by an independent review committee. Results: 46 pts were enrolled, including 78% with progression on or within 60days of last therapy and 22% with no response to last therapy. 39 pts initiated treatment, completed at least one cycle of CFZ, had measurable M-protein, and were evaluable (eval) for response. The mean number of prior therapies (excluding transplant) was 6.4(range 1 to 18). 100% of pts received prior BTZ, 91% prior THAL, 89% prior LEN, and 83% prior stem cell transplantation (SCT). To date, pts received a median of 3 cycles(range 1–9) of CFZ; 22 started at least 4 cycles. The CBR was 26% (10/39 eval pts), including 5 pts achieving PR, 5 pts achieving MR, and 16 additional patients achieving stable disease (SD). Time to response was rapid, frequently occurring in the 1st cycle. CFZ was generally well tolerated; the most common adverse events (AEs) were fatigue(65%), nausea (37%), upper respiratory infection (37%), and diarrhea (33%). Worsening of hematologic parameters: anemia (65%); thrombocytopenia (46%) and neutropenia(20%) were predominantly Grades 1 and 2. Increased creatinine, both drug and non-drug related, was seen in 15/46 pts (33%), but treatment was discontinued in only 3 patients due to a renal adverse event. Acute renal failure was documented in 4 pts (9%), 2 (4%) of whom also had possible tumor lysis. 78% of pts had Grade 1 or 2 peripheral neuropathy (PN) at baseline. Exacerbation of PN was rare, and there were no study discontinuations or dose reductions due to PN. Conclusions: In the context of this heavily pre-treated MM population, single agent CFZ was able to induce CBR in 26% of MM patients, the majority of whom had failed BTZ, LEN, THAL, and SCT. CFZ was generally well-tolerated, and toxicities were manageable. Importantly, exacerbation of pre-existing PN was rare and did not result in dose reduction or discontinuation of therapy. These observations support further evaluation of CFZ as a promising new agent in MM. Enrollment is proceeding at an escalated dose (based on tolerability) in this trial. Additional studies of CFZ in patients who are less heavily pretreated and in combination with other chemotherapy agents are ongoing.

Abstract Abstract 430 Background: Peripheral neuropathy (PN) is a feature of multiple myeloma (MM) itself as well as a debilitating side effect and major dose-limiting toxicity of thalidomide (THAL) and bortezomib (BTZ) (Chaudry et al, J Peripher Nerv Syst. 2008). Although the mechanism of BTZ-induced PN (BIPN) is unknown, PN may not be a proteasome inhibitor class effect. Carfilzomib (CFZ) is a highly selective proteasome inhibitor with activity in relapsed or refractory MM. CFZ overcomes BTZ-resistance in vitro (Kuhn et al, Blood 2007), lacks the off-target activities of BTZ (Kapur et al, Blood 2008), and does not cause neurotoxicity in long-term chronic (e.g. up to 9 months) animal toxicology studies (Kirk et al, Blood 2008). In Phase I and 1b/2 trials (total n=138), CFZ was not associated with dose-limiting PN. Here we report on the experience of CFZ treatment from two ongoing Phase 2 trials in relapsed or refractory MM. Methods: Patients with relapsed or refractory MM received CFZ, 20 mg/m2 IV, Days 1, 2, 8, 9, 15, and 16 in a 28-day cycle for up to 12 cycles on studies PX-171-003 and PX-171-004. Neuropathy history, neurological physical exam and PN-related quality of life data (FACT-GOG/NTx v 4.0 scores) were collected at screening. Prospective neurological exams and subjective reporting of PN using the FACT-GOG/Ntx subscale v.4 questionnaire occurred every 2 cycles until study discontinuation to proactively assess for PN. Adverse Event (AE) data were also collected. AEs reported as ‘neuropathy peripheral', ‘neuropathic pain', ‘neuropathy', and ‘peripheral sensory neuropathy' were included as PN. AE reports of ‘paraesthesias' and ‘dysesthesias' were counted separately. Results: To date, baseline data are availabel for 136 patients. At screening, 73 (54%) patients had active PN, including 64 (47%) with Grade (G) 1 and 9 (7%) with G2. 111 (82%) patients had a history of PN which was attributed to prior chemotherapy, 86 cases of which were attributed to either THAL or BTZ. THAL was implicated in 57 cases, BTZ in 45 cases, and both THAL and BTZ in 17 cases. For 27 of these patients, PN was the primary reason for THAL or BTZ discontinuation. The mean number of CFZ doses was 27 (4.5 four-week cycles) and 27 (20%) patients completed at least 8 cycles. Peripheral neuropathy AEs (all grades) were reported in 21 (15%) patients; 12 (9%) cases were considered possibly related to CFZ. Grade ≥ 3 PN was reported in only 3 (2%) patients. In one patient, the Grade 3 neuropathy lasted from treatment days 2 to 3 (i.e., < 36 hours) and resolved; the patient continued on CFZ at full dose for 30 days before discontinuing study due to progressive MM. In a second patient, Grade 3 neuropathy occurred on study day 91. The dose was reduced from 20 mg/m2 to 15 mg/m2, at the same twice-weekly frequency; the PN resolved to G1 and the patient continued on therapy until day 133. The third patient had G3 PN that occurred from days 260-281 and resolved to G1 while still on full dose CFZ. This patient completed the full 12-cycle protocol (∼1 year CFZ treatment). Paraesthesias and dysesthesia were reported in 10 (7%) patients; all were G1 or 2. There were no missed doses or CFZ treatment discontinuations due to PN, paraesthesias or dysesthesias. Comparative FACT-GOG/Ntx subscale scores were availabel for 95 patients. There was no statistically significant change in FACT-GOG/NTx scores from baseline to the end of the study. Neurological exams did not identify any additional peripheral neuropathy beyond those reported as AEs. Conclusions: In MM patients receiving CFZ therapy, reports of PN, paraesthesias and dysesthesia are generally mild and do not result in missed doses or CFZ discontinuation, allowing long-term treatment and prolonged disease control. These data, along with the experience from other clinical trials, indicate that PN is not a class effect of proteasome inhibitors. Disclosures: Vij: Proteolix: Consultancy, Research Funding. Wang:Proteolix, Inc.: Research Funding. Stewart:Genzyme, Celgene, Millenium, Proteolix: Honoraria; Takeda, Millenium: Research Funding; Takeda-Millenium, Celgene, Novartis, Amgen: Consultancy. Lonial:Celgene: Consultancy; Millennium: Consultancy, Research Funding; BMS: Consultancy; Novartis: Consultancy; Gloucester: Research Funding. Trudel:Celgene: Honoraria, Speakers Bureau; Ortho Biotech: Honoraria. Jakubowiak:Millennium Pharmaceuticals, Inc.: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Centocor Ortho Biotech: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Exelixis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Bristol-Myers-Squibb: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Belch:Ortho Biotech: Honoraria, Research Funding. Bahlis:Celgene: Honoraria, Speakers Bureau; Ortho Biotech: Honoraria, Speakers Bureau. Le:Proteolix, Inc.: Employment. Cruickshank:Proteolix, Inc.: Employment. Bennett:Proteolix: Employment. Molineaux:Proteolix, Inc.: Employment, Equity Ownership. Siegel:Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Millennium: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau.

Abstract Abstract 1875 Introduction: Carfilzomib (CFZ) is a next-generation proteasome inhibitor that has demonstrated durable single-agent antitumor activity in patients (pts) with relapsed and/or refractory multiple myeloma (R/R MM). Previously we have shown that unfavorable cytogenetic features, defined as presence of any of del 13 or hypodiploidy by metaphase cytogenetic analysis and/or del 17p13, t(4;14), t (14;16) by fluorescence in situ hybridization (FISH), did not appreciably affect overall (≥PR) and clinical benefit (≥MR) response rates (ORR and CBR) in PX-171-003-A1, a large phase 2 study of single-agent CFZ in pts with R/R MM (Jakubowiak et al. Ann Oncol. 2011;22(S4): Abstract 117). The objectives of the present analysis were to evaluate the impact of specific cytogenetic abnormalities on efficacy and treatment outcomes. Methods: Pts with unfavorable cytogenetic abnormalities (defined above) were eligible for inclusion in this analysis. All pts received CFZ at 20 mg/m2 IV on days 1, 2, 8, 9, 15, and 16 of 28-day cycles (C) and were dose-escalated to 27 mg/m2 at C2. Pts were treated for up to 12 C. Responses were assessed by International Myeloma Working Group criteria, with minimal response (MR) by European Group for Blood and Marrow Transplantation criteria. Assessments were confirmed by an Independent Review Committee (IRC). Results: A total of 234 pts were included in this analysis. Metaphase cytogenetic data were available for 203 pts (87%), and FISH data were available for 210 pts (90%); 178 pts had both (76%). Seventy-five of 234 pts (32%) had ≥1 abnormality and represented the unfavorable group in this analysis. Of these, 49 (65%) had abnormalities detected via metaphase cytogenetics, 47 (63%) by FISH, and 21 (28%) by both methods. Characteristics of pts in the unfavorable and normal/favorable groups were comparable overall, with the exception of a higher proportion of pts with International Staging System stage II/III in the unfavorable group (83% vs 64%). Response rates per the IRC, presented previously, included an ORR of 30% for pts with ≥1 abnormality compared with 23% for pts with none. The corresponding CBRs were 34% and 40%, respectively. Duration of response (DOR) and time to progression (TTP) values were 7 months (mo) (95% CI 4–9) and 4 mo (95% CI 3–6), respectively, for pts with ≥1 abnormality and 8 mo (95% CI 6–12) and 5 mo (95% CI 3–6), respectively, for pts with none. The ORRs, CBRs, and disease control rates (DCRs) according to specific cytogenetic abnormalities are presented below. Response rates were largely unaffected by the presence of specific unfavorable cytogenetic abnormalities, with the possible exceptions of trends toward a higher response rate for t(4;14) and a lower rate for t(14;16), although the latter abnormality was only noted in 3 pts. The trend for better response rates in pts with t(4;14) corresponded to a DOR of 5.6 mo (95% CI 2.8–10.2). In contrast, the DOR appeared shorter for the subgroup of pts with del 17p13 (4.6 mo, 95% CI: 3.7–Not reached). Time-to-event endpoints including TTP are being analyzed for these and the other subpopulations, and data on these will be presented, along with overall survival stratified by cytogenetic abnormality. Conclusions: CFZ demonstrated comparable response rates in pts with relapsed/refractory MM in both the absence and presence of unfavorable cytogenetic abnormalities in the 003-A1 study. Similarly, in the phase 2 PX-171-004 study, no significant difference in response rates between unfavorable and normal/favorable groups has been observed in a population of less heavily-pretreated pts with relapsed or R/R MM. Taken together, the results of these and other analyses to date suggest that responses to single-agent CFZ can be achieved in heavily pretreated pts and that overall, these responses appear not to be significantly influenced by poor prognostic cytogenetic features. Further analyses from studies with CFZ in newly diagnosed MM and in less heavily-pretreated pts are needed to determine whether a trend toward lower response rates and DOR for pts with del 17p13 is consistently observed in other populations. Disclosures: Jakubowiak: Ortho Biotech: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Celgene: Consultancy, Honoraria, Speakers Bureau; Millennium Pharmaceuticals, Inc.: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Onyx Pharmaceuticals: Consultancy, Membership on an entity's Board of Directors or advisory committees; Bristol-Myers Squibb: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Exelixis: Consultancy, Honoraria. Off Label Use: Use of the investigational agent carfilzomib, proteasome inhibitor, in the treatment of relapsed and/or refractory multiple myeloma. Siegel:Millennium: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees. Singhal:Celgene: Speakers Bureau; Millennium: Speakers Bureau; Onyx Pharmaceuticals: Research Funding. Martin:Celgene: Honoraria; Onyx Pharmaceuticals: Consultancy. Lonial:Onyx: Consultancy; Bristol-Myers Squibb: Consultancy; Novartis: Consultancy; Celgene: Consultancy; Millennium Pharmaceuticals, Inc.: Consultancy; Merck: Consultancy. Kukreti:Celgene: Honoraria. Bahlis:Celgene: Honoraria, Speakers Bureau. Alsina:Millennium: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees; Allergan: Research Funding. Kunkel:Onyx Pharmaceuticals: Consultancy; Threshold: Consultancy; VLST biothech: Consultancy. Wong:Onyx Pharmaceuticals: Employment, Equity Ownership. Orlowski:Onyx Pharmaceuticals: Honoraria, Membership on an entity's Board of Directors or advisory committees. Stewart:Celgene Corporation: Consultancy, Research Funding; Millenium: Consultancy, Research Funding; Novartis: Consultancy, Research Funding; BMS: Consultancy, Research Funding; Onyx: Consultancy, Research Funding. Jagannath:Millennium: Honoraria; Celgene: Honoraria; Onyx Pharmaceuticals: Honoraria; Merck: Honoraria; OrthoBiotec. Imedex: Membership on an entity's Board of Directors or advisory committees; Medicom World Wide: Membership on an entity's Board of Directors or advisory committees; Optum Health Education: Membership on an entity's Board of Directors or advisory committees; PER Group: Membership on an entity's Board of Directors or advisory committees. Wang:Onyx Pharmaceuticals: Research Funding.

Abstract Abstract 985 Introduction: CFZ is a novel and highly selective epoxyketone proteasome inhibitor currently in clinical development for the treatment of multiple myeloma (MM). Ph 1 and 2 studies with CFZ have demonstrated durable single-agent antitumor activity in pts with relapsed or refractory (R/R) MM. The present study, PX-171-003-A1, was an open-label, single-arm Ph 2b trial and enrolled patients with multiply relapsed MM whose disease was refractory (defined as <25% response on, or progression during or <60 days after completion of, therapy) to their last treatment regimen. Patients must have received ≥2 prior therapies including: 1) bortezomib (BTZ) and either thalidomide (THAL) or lenalidomide (LEN), and 2) an alkylating agent. Materials and Methods: Pts received CFZ at 20 mg/m2 on a QDx2 schedule (Days 1, 2, 8, 9, 15, and 16 every 28 days) in cycle (C) 1 and were dose escalated to 27 mg/m2 on the same schedule thereafter for up to 12 C. Pts completing 12 C were eligible to enter an extension study (PX-171-010). The primary endpoint was overall response rate (ORR) (≥ partial response [PR]). Secondary endpoints included: clinical benefit response (CBR) (ORR + Minimal response [MR]), duration of response for ≥PR (DOR), overall survival (OS), time to progression (TTP), progression free survival (PFS), and safety. Responses and progression were determined according to the International Myeloma Working Group (IMWG) criteria and were assessed and confirmed by an Independent Response Committee (IRC). Results: 266 pts were enrolled with a median duration of MM of 5.4 years including 83% whose disease had progressed on or within 60 d of last therapy and 17% whose disease had achieved <25 % response to the regimen immediately preceding study entry. Of the 266 pts enrolled pts, 257 were evaluable for response; 9 patients were considered not evaluable based on missing baseline or lacking at least one post-baseline M-protein. An ORR (≥PR) of 24% with a median DOR of 7.4 mo (range 6.2–10.3) was determined. Responses are detailed in the table. The CBR (ORR + MR) was 36%. Median DOR of pts with MRs was 6.3 months, indicating that long-term MRs were observed. An additional 32% (83 pts) achieved SD for at least 6 wks. To date, 79 pts (30%) completed ≥6 C and >11% of pts have completed all 12 C of protocol specified therapy and most have entered the extension protocol; 15 pts remain on study (all >10 C). OS and TTP data for the overall population will also be reported. The enrolled pts in this study were heavily pretreated having received a median of 5 prior lines of therapy (range 1–20, median of 13 anti-myeloma agents). 85% of pts had received at least 2 and 37% had received at least 3 drugs in the regimen just prior to entering the study. Prior anti-myeloma agents included 99.6% (265/266 pts) BTZ (median 2 prior regimens containing BTZ), 99.6% either THAL (74%) or LEN (94%), 98% corticosteroids, 91% alkylating agents, and 74% stem cell transplant; 65% of pts were refractory to BTZ at any point in time prior to study entry. The most common treatment-emergent adverse events ≥ Grade (G) 3 regardless of relationship to study drug were predominantly hematologic and included thrombocytopenia (22%), anemia (20%), lymphopenia (10%), pneumonia (8%), neutropenia (8%), fatigue (7%), hyponatremia (5%), and hypercalcemia (5%). Although 206 pts (77%) had G1/2 peripheral neuropathy (PN) at baseline, new onset PN was infrequent and G ≥3 PN occurred in <1%. Interestingly, in this subset of patients, efficacy response was nearly identical to that seen in the full study population with an ORR (≥PR) of 24%. Conclusions: Single-agent CFZ achieved durable responses in pts with R/R MM whose disease had relapsed after all available therapies including BTZ and immunomodulatory agents. The CBR and median DOR achieved with this steroid-sparing regimen establish that CFZ has the potential to offer substantial clinical benefit to patients with relapsed or refractory disease. CFZ was well-tolerated and side effects were clinically manageable with no new or unexpected toxicities observed. Importantly, exacerbation of pre-existing PN was uncommon. Cumulative side effects were not observed, allowing prolonged single-agent dosing for chronic disease control. Disclosures: Siegel: Millenium: Consultancy, Honoraria; Celgene: Consultancy, Honoraria. Martin:Celgene: Honoraria; Onyx: Consultancy. Wang:Celgene: Research Funding; Onyx: Research Funding; Millenium: Research Funding; Novartis: Research Funding. Vij:Onyx: Honoraria. Jakubowiak:Millennium Pharmaceuticals, Inc.: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Celgene: Consultancy, Honoraria; Centocor Ortho Biotech: 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; Bristol-Myers Squibb: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees. Jagannath:Millenium, OrthoBiotec, Celgene, Merck, Onyx: Honoraria; Imedex, Medicom World Wide, Optum Health Education, PER Group: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Lonial:Millennium: Consultancy, Research Funding; Celgene: Consultancy, Research Funding; Novartis: Consultancy, Research Funding; BMS: Consultancy, Research Funding; Onyx: Consultancy, Research Funding. Kukreti:Celgene: Honoraria; Roche: Honoraria; Ortho Biotech: Honoraria. Alsina:Millenium: Consultancy, Research Funding; Celgene: Research Funding; Novartis: Consultancy. Zonder:Millenium: Consultancy, Honoraria, Research Funding; Cephalon: Research Funding; Celgene: Honoraria. Wong:Onyx Pharmaceuticals: Employment. Vallone:Onyx Pharmaceuticals: Employment. Chang:Onyx Pharmaceuticals: Employment. Kauffman:Onyx Pharmaceuticals: Employment. Stewart:Millennium: Consultancy; Celgene: Honoraria. Singhal:Celgene: Speakers Bureau; Takeda/Millenium: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Onyx : Research Funding.