Stewart, A. Keith

Abstract Background: Thalidomide and its analogue lenalidomide have high response rates among patients with newly diagnosed as well as previously treated myeloma. Pomalidomide (CC4047) is the newest immunomodulatory (IMiD) agent that has shown single-agent activity in phase I studies. We report on the first Phase 2 trial of pomalidomide combined with low dose dexamethasone (Pom/dex) in patients with relapsed or refractory multiple myeloma. Methods: 37 patients (21 male and 16 female) were enrolled. Pomalidomide was given orally 2 mg daily on days 1–28 of a 28-day cycle. Dexamethasone was given orally at a dose of 40 mg daily on days 1, 8, 15 and 22 of each cycle. Response was assessed by the International Myeloma Working Group Uniform Response criteria. All patients received aspirin 325 mg daily as prophylaxis against DVT. Results: The median age was 66 years (range, 40 – 88). All patients were evaluable for response and toxicity, and all analysis were done on intent to treat basis. All patients had received prior therapy; 38% had 3 prior regimens; 35% had 2 prior regimens and 27% had one prior regimen. 76% had previous autologous stem cell transplant (ASCT) and 24% had 2 prior ASCT. 62% had previous IMiD therapy. Toxicity was mild and consisted primarily of myelosuppression. Grade 3 neutropenia occurred in 31%; grade 3 thrombocytopenia 3%; grade 3 anemia 3 %. Other grade 3/4 toxicities seen in less than 5% pts included: diarrhea, atrial fibrillation, pneumonia, dehydration and renal insufficiency. 16 % had grade 1/2 neuropathy. No grade 3 neuropathy was seen and there have been no thromboembolic events. Thirty (81%) patients are continuing study treatment. Seven patients have discontinued treatment due to: disease progression (5), died on study (1) and the medical doctor’s discretion (1). Twenty three of 37 patients (62%) achieved an objective response to therapy; including 9 (24%) with VGPR; 14 patients (38%) with PR; 6 (16%) with stable disease. Objective responses were seen in 4 of 13 patients (29%) who were refractory to lenalidomide. Conclusions: Pomalidomide plus dexamethasone (Pom/dex) is highly active and well tolerated for treatment of relapsed/refractory multiple myeloma with an objective responserate of 62%, including a 29% response rate among patients who are lenalidomiderefractory.

Abstract Background: (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 disease after one to three prior therapies. Methods: PX-171-004 is an open-label, multicenter study. Pts are stratified into bortezomib (BTZ) naïve, BTZ responsive (> 6 month response) or BTZ non-responsive(< 6 months response) cohorts. 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. Results: 31 patients were enrolled, including 45% BTZ naïve, 45% BTZ responsive, and 10% BTZ non-responsive. 29 pts initiated therapy, completed at least one cycle of CFZ, had measurable M-protein and were evaluable for response. The mean number of prior therapies (excluding transplant) was 2.4;65% received prior thalidomide(THAL), 36% prior lenalidomide (LEN) and 87% prior stem cell transplant (SCT).To date, pts received a median of 4 cycles (range 1–8) of CFZ. 19 pts started at least 4 cycles, and 17 remain on therapy. In the evaluable BTZ naïve population (n=13), the overall response rate (ORR) was 54%, including 1 complete response (CR), 2 very good partial responses (VGPR), and 4 partial responses (PR). There were 4 additional pts with stable disease (SD). In 1 pt with insufficient data to evaluate response, due to tumor lysis syndrome (TLS) onset after 2 CFZ doses, an M-protein drop was noted that suggested a PR. Time to response was rapid, frequently occurring in the 1st cycle. There have been no progressions in this subset. With a median follow-up of 109 days, the time-to-progression(TTP) has not yet been reached, and all responders remain in remission. In 16 evaluable BTZ prior treated pts, 3 pts (19%) achieved PR, 1 (6%) pt achieved a minimal response (MR, as defined by EBMT criteria), and 9 pts had SD. The median TTP is 169 days for this subset. CFZ was generally well tolerated. The most common non-hematologic adverse events (AEs) were fatigue (61%), nausea (58%), vomiting (36%), and insomnia (32%). Worsening of hematologic parameters: neutropenia (32%), anemia (29%), and thrombocytopenia (23%) were primarily Grade 1/2; Grade 3/4 occurred in 10% or less of pts. Reports of peripheral neuropathy (PN) were uncommon. Increased creatinine, both drug and non-drug related, was seen in 5 pts (16%), but treatment was discontinued in only 1 pt due to a renal adverse event. Possible tumor lysis was reported in 2 BTZ naïve patients and resulted in early drug discontinuation in 1 pt, as described above; the 2nd event was fatal. Conclusions: The preliminary results of this trial indicate that CFZ has substantial activity as a single agent in relapsed MM patients, with an ORR of >50% in BTZ naïve patients, indicating better activity in this pt population. CFZ was generally well tolerated, and toxicities were manageable. TLS, which was observed in 2 pts, may be a reflection of the robust drug activity of CFZ. As observed in prior studies with CFZ, reports of PN were uncommon. These observations support further evaluation of CFZ as a promising new agent in MM. Enrollment in this study is ongoing, and additional studies of CFZ in combination with other chemotherapy agents in MM pts are underway.

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 3861 Poster Board III-797 Previous studies have reported that multiple myeloma (MM) patients (pts) with t(4;14) identified by FISH who are treated with a single ASCT as part of first-line therapy have worse outcomes than those lacking this adverse cytogenetic marker; two trials have described a median progression-free survival (PFS) of only 8-9 months and median overall survival (OS) of 18 mos in this setting (Chang H, et al. Bone Marrow Transplant 2005; 36: 793; Gertz M, et al. Blood 2005; 106: 2837). Since the novel agent bortezomib appears to have efficacy in patients with t(4;14), we designed a phase II protocol in which pts receive induction with pegylated liposomal doxorubicin, bortezomib and dexamethasone (DBD) x 4 cycles, followed by post-induction therapy with oral cyclophosphamide 300 mg/m2 days 1,8 15, 22 with bortezomib 1.5 mg/m2 days 1,8,15 and prednisone 100 mg q 2 days of a 28-day cycle (CyBor-P) x 8 additional cycles. Maintenance therapy with dexamethasone (dex) 40 mg/month was then administered until progression. Although elective stem cell collection was recommended after induction, routine ASCT was not performed in the absence of disease progression. Between February 2008-August 2009, 153 newly diagnosed MM pts were screened for t(4;14) in 7 Canadian centers, and 14 (9%) were found to be positive by FISH. Four did not meet the critieria for symptomatic MM, 2 had received ≥ 2 mos of prior therapy while 8 were entered onto study. One of these was later determined to have a variant abnormality of chromosome 4 but not t(4;14) and underwent ASCT after induction; this pt is included in the safety analysis only. The median age was 56 (49-69) and 43% were male. The median percent nuclei positive for t(4;14) was 30% (10-41%), serum β2-microglobulin 394 nmol/L (190-1695) and albumin 34 g/L (28-39); one pt had ISS stage 1,3 had stage 2 and 3 had stage 3 MM. Immunoglobulin subtype included IgGκ in 2 and IgAκ in 2 and IgAλ in 3. All pts have completed DBD induction, with the best response in the 7 evaluable pts consisting of PR in 2 and VGPR in 5; one in PR progressed quickly after induction and has achieved nCR after D-PACE followed by ASCT and lenalidomide maintenance. Four are receiving post-induction therapy with CyBor-P currently, with VGPR in 3 and PR in 1. No SAEs or grade3/4 neutropenia or thrombocytopenia has occurred; other toxicities were mild, with grade 2 skin toxicity noted in 37.5% and grade 2 neurotoxicity observed in 7.4%. All pts are alive at a median follow-up (F/U) of 8 mos (2-11), and 6 (86%) are free of progression. We conclude: 1) the incidence of t(4;14) in newly diagnosed MM pts appears to be lower than the 15% anticipated; 2) 28% of newly diagnosed pts with this entity have asymptomatic MM; 3) preliminarily, DBD induction has resulted in ≥ PR in all pts although 1 progressed quickly; 4) this bortezomib-based regimen is very well-tolerated; 5) longer F/U is required to determine the PFS and OS with this approach. Disclosures: Reece: Ortho Biotech: Honoraria, Research Funding, Speakers Bureau; Celgene: Honoraria, Research Funding, Speakers Bureau. Off Label Use: Use of bortezomib as part of initial therapy with pegylated liposomal doxorubicin and dexamethasone. Piza Rodriguez:Ortho Biotech: Honoraria. Belch:Ortho Biotech: Honoraria, Research Funding. Shustik:Ortho Biotech: Honoraria. Bahlis:Ortho Biotech: Honoraria; Celgene: Honoraria. White:Ortho Biotech: Honoraria, Research Funding. Chen:Ortho Biotech: Honoraria. Kukreti:Celgene: Honoraria. Stewart:Genzyme, Celgene, Millenium, Proteolix: Honoraria; Takeda, Millenium: Research Funding; Takeda-Millenium, Celgene, Novartis, Amgen: Consultancy. Trudel:Ortho Biotech: Honoraria, Research Funding.

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 863 Background: Patients with MM who have progressed after multiple novel agents have limited treatment options. Pomalidomide (CC4047) is the newest immunomodulatory (IMiD) agent. Pom/dex using a dose of 2 mg/day has demonstrated response rates (≥PR) of 63% in relapsed MM (Lacy, JCO 2009, 27:5008-5014) and 32% in a lenalidomide-refractory cohort (Lacy, Leukemia, in press). The maximum tolerated dose has been determined to be 4 mg/day for 21 of 28 days (Richardson, ASH, 2009), We opened two sequential phase II trials using the Pom/dex regimen at differing doses to study the efficacy of this regimen in patients who have failed both lenalidomide and bortezomib. Methods: Patients refractory to both lenalidomide and bortezomib therapy; defined as relapsing on or within 60 days of stopping each regimen, were enrolled. Pomalidomide was given orally 2 mg daily (Cohort A) or 4mg daily (Cohort B) on days 1–28 of a 28-day cycle with oral dexamethasone given 40 mg daily on days 1, 8, 15 and 22. Response was assessed by the International Myeloma Working Group Uniform Response criteria. All patients received aspirin 325 mg daily for DVT prophylaxis. Results: 35 patients with relapsed and resistant/refractory to both lenalidomide and bortezomib were enrolled in each cohort. The median age was 62 years (range, 39–77) in Cohort A and 61 (range, 45–77) years in Cohort B. The median time from diagnosis to enrollment was 57 months for Cohort A (range 12–249) and 72 months(range, 13–183) for Cohort B. 15 patients had high risk molecular markers in Cohort A and 16 in Cohort B. The median number of prior regimens was 6 in both groups. The median (range) duration on treatment was 5(1-13) and 2(0-6) cycles in cohorts A and B respectively. Toxicity at least possibly attributed to drug consisted primarily of myelosuppression: grade 3/4 neutropenia (37% Cohort A vs. 55% Cohort B); grade 3/4 thrombocytopenia (11% Cohort A vs. 13% Cohort B); and grade 3/4 anemia (9% Cohort A vs. 16% Cohort B). Grade 3/4 non-hematologic toxicities occurred in 23% Cohort A vs. 13% Cohort B. Grade 1 or 2 fatigue was the most common non-hematologic toxicity seen in 43% Cohort A vs. 52% Cohort B. Grade 1 or 2 neuropathy occurred in 17% Cohort A vs. 16% Cohort B. Other non-hematologic toxicities occurring in <5% included pneumonitis, hyperglycemia, renal failure, thrombosis. One patient in cohort B had grade 4 hepatitis. Confirmed responses in Cohort A consisted of VGPR 14%, PR 11%, and MR 24% (ORR 49%, 95% CI: 31–66), and responses in Cohort B consisted of VGPR 9%, PR 20%, and MR 12% (ORR 40%, 95% CI: 23–58). The median follow-up on alive patients was 7.5 months, and 3 months in Cohorts A and B, respectively. The median PFS in cohorts A and B are respectively 6.4 months (95% CI: 4.7-NR) and 3.3 months (95% CI: 2.3-NR). Conclusions: Pom/dex is remarkably active and well tolerated in this heavily pre-treated population of dual bortezomib/lenalidomide-refractory MM patients. The majority of patients have not progressed and objective responses (MR or better) are seen in 40–49%. This study confirms therapeutic benefit for Pom/dex in patients relapsing after other novel therapies. These studies do not show an advantage for the 4 mg/day on days 1–28 of each 28 day cycle did not show an advantage over the 2 mg/day on days 1–28 of each 28 day cycle. Disclosures: Lacy: Celgene: Research Funding. Gertz:Celgene: Honoraria; Millennium: Honoraria, Membership on an entity's Board of Directors or advisory committees. Dispenzieri:Celgene: Honoraria, Research Funding; Binding Site: Honoraria. Kumar:Celgene: Consultancy, Research Funding; Millennium: Research Funding; Merck: Consultancy, Research Funding; Novartis: Research Funding; Genzyme: Consultancy, Research Funding; Cephalon: Research Funding. Fonseca:Genzyme: Consultancy; Medtronic: Consultancy; BMS: Consultancy; AMGEN: Consultancy; Otsuka: Consultancy; Celegene: Consultancy, Research Funding; Intellikine: Consultancy; Cylene: Research Funding; Onyx: Research Funding; FISH probes prognostication in myeloma: Patents & Royalties. Bergsagel:Celgene: Consultancy; Centocor: Consultancy; Genentech: Consultancy; Amgen: Consultancy; Novartis: Consultancy. Stewart:Celgene: Honoraria.

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.

Abstract Abstract 1876 Carfilzomib (CFZ), 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, is being evaluated in MM patients. The selectivity of CFZ for the proteasome may explain the low rates of peripheral neuropathy (PN) relative to historical data for bortezomib (BTZ). Safety data have been compiled for >700 patients who received CFZ in 9 Phase (Ph) 1 or 2 trials, 4 of which are completed. The majority of patients had relapsed and refractory (R/R) MM, and many had comorbidities including baseline PN and renal insufficiency. This abstract updates and summarizes mature safety data for single-agent CFZ in 526 patients with R/R MM who took part in 1 of 3 Ph 2 studies and is a follow-up with more mature data compared with those presented at ASH 2010. Patients enrolled and treated with CFZ in the following trials are included in this analysis: PX-171-003 (conducted in 2 parts, a pilot study, PX-171-003-A0 [R/R MM], followed by PX-171-003-A1 [R/R MM]), PX-171-004 (relapsed MM), and PX-171-005 (R/R MM with varying degrees of renal function). In all studies, CFZ was dosed on Days 1, 2, 8, 9, 15, and 16 of a 28-day cycle (C). Doses were 20 mg/m2 in C1, escalating to 27 mg/m2 in C2 for all studies with the exception of 005 (15 mg/m2 in C1, 20 mg/m2 in C2, and 27 mg/m2 in C3). Overall, CFZ had a favorable safety profile in these studies. The most frequently reported adverse events (AEs) occurring in ≥30% of patients included fatigue (55%), anemia (47%), nausea (45%), thrombocytopenia (36%), dyspnea (35%), diarrhea (33%), and pyrexia (30%). The most common (≥10% of patients overall) ≥G3 AEs were thrombocytopenia (23%), anemia (22%), lymphopenia (18%), pneumonia (11%), and neutropenia (10%). The assessment of PN was based on a pooled aggregate of PN preferred terms, including neuropathy peripheral, neuropathy, peripheral sensory neuropathy, and peripheral motor neuropathy. PN was reported infrequently (14% overall) across all studies. Although 378 (72%) patients had baseline PN (≤G 2), only 13% reported treatment-emergent symptoms during the study. PN was generally mild to moderate in severity (1.3% G3 PN with no G4 PN), and only 5 patients (1%) required dose modification or discontinuation due to PN. Renal AEs (mainly ≤G2) were reported in 174 (33%) patients, and CFZ was discontinued because of a renal AE in only 21 patients (4%). A summary of CFZ exposure and discontinuation rates is reported in the table. There were a total of 37 (7%) deaths on study, including within 30 days of the last dose of study drug. The primary cause of death was due to disease progression in 22/37 patients (4.2%); however, AEs, including in order of frequency, cardiac events, hepatic failure, and infection, contributed to 14 of these deaths.No. of Patients (%) in Ph 2 MM Studies Who Received Carfilzomib003-A0 (N = 46)003-A1 (N = 266)004 (N = 164)005 (N = 50)All Patients (N = 526)Cycles, mean, n (SD)4.4 (3.4)5.3 (4.1)7.0 (4.4)5.5 (3.7)5.7 (4.2)Completed ≥12 cycles4 (8.7)40 (15.0)47 (28.7)3 (6.0)94 (17.9)Reason for not completing 12 cycles Progressive Disease23 (50.0)157 (59.0)64 (39.0)24 (48.0)268 (51.0) Adverse Event13 (28.3)33 (12.4)26 (15.9)6 (12.0)78 (14.8) Withdrew Consent2 (4.3)22 (8.3)9 (5.5)4 (8.0)37 (7.0) Other4 (8.7)14 (5.3)10 (6.1)028 (5.3) Of the 526 patients included in these analyses, >50% were treated on the 003-A1 dose and schedule (20/27 mg/m2), and fewer than 10% required dose reduction. 18% of patients completed ≥12 cycles (∼1 y) and were eligible to participate in an ongoing, multicenter, open-label Ph 2 study (PX-171-010) to monitor long-term single-agent CFZ safety. To date, patients in this extension trial have not shown evidence of cumulative toxicity. In summary, these data confirm and extend results that were previously presented, namely that single-agent CFZ has an acceptable safety profile in heavily pretreated patients with R/R MM, including those with pre-existing renal dysfunction and PN. Disclosures: Singhal: Onyx Pharmaceuticals: Research Funding, Speakers Bureau; Millennium: Speakers Bureau; Celgene: Speakers Bureau. 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. Martin:Celgene: Honoraria; Onyx Pharmaceuticals: Consultancy. Vij:Onyx Pharmaceuticals: Consultancy, Research Funding; Celgene: Research Funding, Speakers Bureau; Millennium: Speakers Bureau. Wang:Onyx Pharmaceuticals: Research Funding. Jakubowiak:Ortho Biotech: 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; 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. Lonial:Millennium: Consultancy; Celgene: Consultancy; Novartis: Consultancy; BMS: Consultancy; Onyx Pharmaceuticals: Consultancy; Merck: Consultancy. Kukreti:Celgene: Honoraria. Zonder:Millennium: Consultancy, Research Funding, Speakers Bureau; Celgene: Speakers Bureau; Medtronics: Honoraria; Amgen: Consultancy. Wong:Onyx Pharmaceuticals: Employment, Equity Ownership. McCulloch:Onyx Pharmaceuticals: Employment. Niesvizky:Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Millennium Pharmaceuticals, Inc.: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Onyx: Research Funding; Seattle Genetics Inc: Research Funding, Speakers Bureau. Orlowski:Onyx Pharmaceuticals: Honoraria, Membership on an entity's Board of Directors or advisory committees. Stewart:Celgene: Consultancy, Research Funding; Millennium: Consultancy, Research Funding; Novartis: Consultancy, Research Funding; BMS: Consultancy, Research Funding; Onyx: Consultancy, Research Funding. Kotlovker:Onyx Pharmaceuticals: Employment. 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.

Abstract Abstract 621 Background: Two- and three-drug regimens incorporating bortezomib (Velcade®, V), lenalidomide (Revlimid®, R), dexamethasone (D), or cyclophosphamide (C) have been shown to be effective and well tolerated in previously untreated multiple myeloma (MM). Combining all four drugs in a single regimen (VDCR) may further enhance efficacy. Published results from the phase 1 dose-escalation portion of the non-comparative, multi-center EVOLUTION study showed that the VDCR regimen was highly active and generally well tolerated (Kumar et al Leukemia 2010). Here we present updated results from the phase 2 portion of the trial, focusing on efficacy and safety of the VDCR, VDR, and VDC regimens. Methods: Previously untreated patients with measurable disease were randomized to one of four treatment groups receiving up to eight 21-d cycles of VDCR (V 1.3 mg/m2 d 1, 4, 8, 11; D 40 mg d 1, 8, 15; R 15 mg d 1–14; C 500 mg/m2 d 1, 8), VDR (VD as in VDCR but with R 25 mg d 1–14), VDC (VDC as in VDCR), or VDC-mod (as for VDC but with an additional dose of C on d 15) as induction therapy, followed by four 42-d maintenance cycles of V 1.3 mg/m2 (d 1, 8, 15, 22) (all treatment arms). Patients eligible for autologous stem cell transplant (SCT) could undergo stem cell mobilization any time after cycle 2 and SCT any time after cycle 4. The primary endpoint was the combined complete response (CR) + very good partial response (VGPR) rate; secondary endpoints included safety/tolerability, time to response, duration of response, progression-free survival, and rate of minimal residual disease (MRD) negativity. Responses were assessed according to International Myeloma Working Group (IMWG) uniform criteria using an automated computer algorithm. Adverse events (AEs) were graded using the CTCAE v3.0. Results: Patient characteristics were similar among the groups with respect to age, performance status, ISS stage, and proportion of patients with high-risk cytogenetic features. Patients received a median of 5, 6, 6, and 6 treatment cycles in the VDCR, VDR, VDC, and VDC-mod arms, respectively; 65%, 60%, 52%, and 47% of patients had dose reductions of any drug. In the VDCR, VDR, VDC, and VDC-mod arms, respectively, 52%, 62%, 58%, and 65% of patients completed treatment; 31%, 43%, 24%, and 41%, respectively, underwent SCT. In the phase 2 response-evaluable patients (n=132), all treatment regimens showed substantial efficacy, with CR+VGPR rates of 59% (VDCR), 50% (VDR), 41% (VDC), and 59% (VDC-mod) (Table) (includes pre-transplant responses only in SCT patients). Of MRD-assessed patients, 46% (21/46) of those who achieved CR (including sCR) or nCR were MRD-negative; 48% (10/21), 75% (9/12), 0% (0/7) and 33% (2/6) in the VDCR, VDR, VDC and VDC-mod arms, respectively. Median time to first response was similar across arms (range 1.6–1.8 months); median time to best response of CR+VGPR was 4.0 months (VDCR), 3.4 months (VDR), 5.1 months (VDC), and 3.1 months (VDC-mod). Median duration of response has not been reached in any arm to date. All treatment regimens were generally well tolerated. In the VDCR, VDR, VDC, and VDC-mod arms, at least one grade ≥3 AE was observed in 81%, 76%, 79%, and 88% of enrolled patients, respectively; serious AEs were experienced by 42%, 40%, 21%, and 41% of patients, and AEs resulting in study discontinuation were reported for 19%, 17%, 12%, and 6% of patients. The five most common all-grade AEs across all treatment groups were fatigue (range 47–67%), nausea (36–67%), constipation (40–62%), diarrhea NOS (42–65%), and neutropenia (19–52%). The incidence of grade ≥3 (grade ≥2) peripheral neuropathy (PN) was 13% (40%) in the VDCR arm, 14% (45%) VDR, 9% (48%) VDC, and 18% (41%) VDC-mod; there was no grade 4 PN. Rates of grade ≥3 neutropenia/thrombocytopenia were 42%/10% for VDCR, 7%/7% VDR, 36%/12% VDC, and 65%/18% VDC-mod. Conclusions: All regimens appear highly active and generally well tolerated in previously untreated MM patients. The four-drug combination did not result in a substantial increase in response rate and was associated with a modest increase in the incidence of hematologic toxicities. Continuous weekly C in the VDC regimen was associated with high response rates and rapid responses, comparable to the VDR and VDCR arms. Outcome data will be presented following longer follow-up. Disclosures: Kumar: Celgene: Consultancy, Research Funding; Millennium: Consultancy, Research Funding; Merck: Consultancy, Research Funding; Novartis: Research Funding; Genzyme: Consultancy, Research Funding; Cephalon: Research Funding; Bayer: Research Funding. Off Label Use: Lenalidomide for treatment of newly diagnosed myeloma. Flinn:Millennium Pharmaceuticals, Inc.: Research Funding. Richardson:Celgene, Millennium, Novartis, Johnson & Johnson: Membership on an entity's Board of Directors or advisory committees. Hari:Celgene: Research Funding. Callander:Millennium Pharmaceuticals, Inc.: Research Funding. Noga:Amgen: Honoraria, Research Funding, Speakers Bureau; Millennium: Consultancy, Honoraria, Research Funding, Speakers Bureau; Ortho-Centicor: Honoraria, Speakers Bureau; Cephalon: Honoraria, Research Funding, Speakers Bureau; Celgene: Honoraria, Research Funding, Speakers Bureau. Stewart:Millennium Pharmaceuticals, Inc.: Honoraria, Research Funding; Celgene: Honoraria. Rifkin:Millennium Pharmaceuticals, Inc.: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Celgene: Speakers Bureau; Amgen: Speakers Bureau; Cephalon: Speakers Bureau; Dendreon: Speakers Bureau. Wolf:Millennium Pharmaceuticals: Consultancy, Honoraria, Speakers Bureau; Genentech and Multiple Myeloma Research: Membership on an entity's Board of Directors or advisory committees; Novartis: Honoraria, Speakers Bureau; OrthoBiotech: Honoraria, Speakers Bureau; Celgene: Honoraria, Speakers Bureau. Estevam:Millennium Pharmaceuticals: Employment. Mulligan:Millennium Pharmaceuticals, Inc.: Employment. Shi:Millennium Pharmaceuticals: Employment. Webb:Millennium Pharmaceuticals: Employment.