Sexton, Rachael

Abstract Dexamethasone is a key component of induction for newly diagnosed multiple myeloma (NDMM), despite common toxicities, including hyperglycemia and insomnia. In the randomized ECOG E4A03 trial, dexamethasone 40 mg once weekly was associated with lower mortality than higher doses. However, the performance of dexamethasone dose reductions below this threshold with regard to progression-free survival (PFS) and overall survival (OS) in NDMM has not been fully characterized. We conducted a secondary pooled analysis of the SWOG 0777 and SWOG 1211 studies of NDMM, which used lenalidomide and dexamethasone (Rd) alone, with or without bortezomib, and with or without elotuzumab. The planned dexamethasone intensity was 40 to 60 mg weekly in all arms. Patients were categorized into FD-DEX (full-dose dexamethasone maintained throughout induction) or LD-DEX (lowered-dose dexamethasone or discontinuation; only permitted for grade 3+ toxicities per both study protocols). Of the 541 evaluated patients, the LD-DEX group comprised 373 patients (69%). There were no differences in PFS or OS between the FD-DEX and LD-DEX groups, which were balanced in terms of age, stage, and performance status. Predictors of PFS and OS in the multivariate models were treatment arm, age ≥70 years, and thrombocytopenia. FD-DEX did not significantly improve either outcome. Our study suggests that dexamethasone dose reductions are common in multiple myeloma, even within clinical trials. Given the many toxicities and unclear benefits of dexamethasone in the era of modern treatment regimens, dexamethasone dose reduction during NDMM induction warrants further prospective studies. These trials were registered at www.clinicaltrials.gov as #NCT00644228 and NCT01668719.

Background: Dex is a key component of induction regimens for NDMM despite common toxicities including insomnia and anxiety. The E4A03 randomized trial (Rajkumar, Lancet Oncol 2010) demonstrated that dex dosed at 40 mg weekly outperformed higher-intensity dex and established this regimen as the standard of care for NDMM. In standard practice as well as clinical trials, however, dex doses are often reduced to 20 mg weekly or lower (if not stopped entirely) among older patients or among patients experiencing toxicities. As a first step toward establishing the equipoise of planned dex dose reductions in NDMM, we investigated outcomes with patients from two previous SWOG trials to understand the impact of dex dose reductions on post-induction outcomes. Methods: This was a secondary analysis of data from two completed NDMM studies, S0777 (comparing VRd vs Rd) and S1211 (comparing Elo-VRd vs VRd). For this secondary analysis, we analyzed the subset of patients who completed all eight 3-week cycles of induction (or six 4-week cycles in the S0777 Rd arm). As shown in Figure 1A, we defined DEX fullDose as patients for whom the starting dex dose (either 40 mg once per week or 20 mg on Days 1, 2, 4, 5, 8, 9, 11, and 12 of 21-day cycles) did not change during induction. In contrast, DEX lowered was defined as patients for whom the end-of-induction dex dose and/or frequency were lower than their starting values. As an exploratory analysis, we also compared PFS and OS between the DEX fullDose (no changes to dex strength during induction) and DEX veryLow (dex dosing reduced ≥50% during induction) subgroups. All analyses were landmarked from the end of induction, defined as 24 weeks from registration, to account for the time-dependent nature of dex treatment received. Survival curves were based on the Kaplan-Meier method and comparisons were made using the log-rank test. Results: Of 541 evaluable patients ( n = 441 from S0777, n = 100 from S1211), dex was reduced during induction in 76% ( n = 410). Compared to DEX fullDose patients, DEX lowered patients were more likely to be anemic (37% vs 26%, p = 0.02) but had similar distributions of age ≥70 (24% of DEX lowered vs 26% of DEX fullDose), Performance Status > 1 (15% vs 12%), ISS stage 3 disease (33% vs 27%), ≥ 60% bone marrow plasma cell burden (37% vs 31%), M-spike > 3 g/dL (48% vs 48%) platelets < 150,000 cells/mm 3 (18% vs 14%), baseline LDH ≥ 190 U/L (36% vs 41%), and baseline CRP ≥ 8 mg/L (27% vs 30%). PFS (Figure 1B) was comparable between DEX lowered (median 36 months, 95% CI 29 to 39 months) and DEX fullDose (median 33 months, 95% CI 24 to 48 months) with p = 0.90. Similarly, OS (Figure 1C) was comparable between DEX lowered [median 77 months, 95% CI 68 months to not reached (NR)] and DEX fullDose (median 92 months, 95% CI 65 months to NR) with p = 0.93. In the DEX veryLow subgroup with ≥50% reduction in dex dosing during induction, median PFS was 39 months (95% CI 34 to 50 months) and median OS was NR (95% CI NR to NR). As shown in Figure 1D and Figure 1E, PFS and OS were comparable between these patients and DEX fullDose patients. Discussion: To our knowledge, this is the first analysis of dex dosing strength in NDMM since E4A03. In two separate randomized trials, over half of patients required dex reductions below a starting dose of ~40 mg weekly. Dex dose reductions during induction had no impact on post-induction PFS and OS, even in the subset of patients who required significant dose reductions. Limitations of our post hoc analysis include heterogeneity between dex dosing schedules and lack of cytogenetic data for all patients. We could not discern specifically why dex was lowered, and it is possible that dex might have been lowered disproportionately commonly in patients who had achieved early responses and thus independently did better. Regardless, these results strongly suggest that maintaining dex 40 mg weekly for the entirety of NDMM induction may be unnecessary in the modern era. Cooperative efforts to study a planned dex de-escalation protocol (i.e., once no longer needed for symptom management or as a pre-medication) alongside patient-reported outcome assessments of symptom burden are being planned. Funding: NIH/NCI/NCTN grants U10CA180888, U10CA180819, U10CA180821, U10CA180820; and in part by Millennium Pharmaceuticals, Inc. (now part of Takeda Pharmaceutical Company), and by Celgene.

8054 Background: The introduction of immunomodulatory agents, proteasome inhibitors, and autologous stem cell transplantation (ASCT) has improved outcomes for patients with multiple myeloma (MM), but those with high risk MM (HRMM) have a poor long-term prognosis. Herein we provide survival outcomes on the first randomized trial in newly diagnosed HRMM, S1211, to follow-up on the previously reported progression-free survival (PFS) (NCT01668719, Usmani SZ et al, Lancet Haem 2021). Methods: S1211 is a randomized phase II trial comparing 8 cycles of lenalidomide, bortezomib and dexamethasone (RVd) induction followed by dose-attenuated RVd maintenance until disease progression with or without elotuzumab (RVd-Elo). Stem cell collection was allowed, but ASCT was deferred until progression. HRMM was defined by one of the following: gene expression profiling high-risk (GEPhi), t(14;16), t(14;20), del(17p), amplification 1q21, primary plasma cell leukemia (pPCL), or elevated serum LDH (> 2X ULN). Median PFS was the primary endpoint, using a one-sided stratified log-rank test at a one-sided significance level of 0.1. Secondary endpoints included overall response rate (ORR), adverse events (AE), serious adverse events (SAE) and OS. Response was assessed using the IMWG 2009 criteria. Results: S1211 enrolled 103 evaluable patients, RVd n=54, RVd-Elo n=49. 74% had ISS II/III, 48% amp1q21, 38% del(17p), 11% t(14;16), 9% GEPhi, 7% pPCL, 5% t(14;20) and 4% elevated LDH (17% >1 feature). With median follow-up of 72 months (mos.), no difference in median PFS was observed [RVd-Elo=29 mos., RVd= 34 mos., HR = 1.11 (80% CI=0.82, 1.49, p=0.66]. No difference in OS was observed [RVd-Elo = median not reached (NR), RVd= 68 mos., HR = 0.85 (80% CI: 0.59, 1.23), p-value = 0.58]. 76% pts had >Grade 3 AEs, no differences in the safety profile were observed. Amongst patients with gain/amp 1q21, median PFS was [RVd-Elo=31 mos., RVd= 37 mos., HR = 1.48 (80% CI= 0.95, 2.31), p=0.25], median OS was [RVd-Elo = 61 mos., RVd= 68 mos., HR = 1.23 (80% CI: 0.72, 2.10), p-value = 0.63]. In patients with del(17p), median PFS was RVd-Elo=41 mos., RVd= 30 mos.[HR = 0.98 (80% CI= 0.60, 1.58), p=0.95], median OS RVd-Elo = NR, RVd= 72 mos., [HR = 0.77 (80% CI: 0.40, 1.48), p-value = 0.61]. Conclusions: In the first randomized HRMM study reported to date, the addition of Elo to RVd induction and maintenance did not improve PFS and OS with a median follow-up of 6 years. Although the median PFS for Del17p subgroup on RVd-Elo arm is higher than RVd, it did not achieve statistical significance. The PFS and OS observed for gain/amp 1q21 and del17p in the RVd control arm may serve as important benchmarks for future enrichment design HRMM clinical trials. The PFS and OS in both arms of the study exceeded the original statistical assumptions and support the role for PI/IMiD combination induction/maintenance therapy for this population. Clinical trial information: NCT01668719.

8507 Background: The introduction of immunomodulatory agents, proteasome inhibitors, and autologous stem cell transplantation (ASCT) has improved outcomes for patients with multiple myeloma (MM), but those with high risk MM (HRMM) have a poor long-term prognosis. To date, no trials have addressed optimal treatment for these patients. Methods: S1211 is a randomized phase II trial (NCT01668719) comparing 8 cycles of lenalidomide, bortezomib and dexamethasone (RVd) induction followed by dose-attenuated RVd maintenance until disease progression with or without elotuzumab. Stem cell collection was allowed, but ASCT was deferred until progression. HRMM was defined by one of the following: gene expression profiling high-risk (GEPhi), t(14; 16), t(14; 20), del(17p) or amplification 1q21, primary plasma cell leukemia (pPCL) and elevated serum LDH (> 2X ULN). Median progression-free survival (PFS) was the primary end-point, using a one-sided stratified log-rank test at a one-sided significance level of 0.1. Secondary endpoints included overall response rate (ORR), adverse events (AE), serious adverse events (SAE) and OS. Response was assessed using the IMWG 2009 criteria. Results: S1211 enrolled 103 evaluable patients, RVd n = 54, RVd-Elo n = 49. 75% had ISS II/III, 47% amp1q21, 38% del17p, 12% t(14; 16), 9% GEPhi, 7% pPCL, 5% t(14; 20) and 4% elevated serum LDH (18.5% > 1 feature). With median follow-up of 53 months (mos.), no difference in median PFS was observed [RVd-Elo = 31 mos., RVd = 34 mos.,HR = 0.968 (80% CI = 0.697-1.344), p = 0.449]. No difference in OS was observed [RVd-Elo = 68 mos, RVd = not reached, HR = 1.279 (80% CI: 0.819, 2.000), p-value = 0.478]. 72% pts had > Grade 3 AEs, no differences in the safety profile were observed except >Grade 3 infections (RVd 8%, RVd-Elo 16%), >Grade 3 sensory neuropathy (RVd 8%, RVd-Elo 13%). Conclusions: In the first randomized HRMM study reported to date, the addition of elotuzumab to RVd induction and maintenance did not improve patient outcomes. However, the PFS and OS seen in both arms of the study exceeded the original statistical assumptions and support the role for PI/IMiD combination maintenance therapy for this patient population. The S1211 data will serve as an important benchmark for future HRMM clinical trials. Clinical trial information: NCT01668719 .

Abstract Purpose: Treatment of multiple myeloma has evolved tremendously and optimal utilization of available therapies will ensure maximal patient benefits. Patients and Methods: We report the Southwest Oncology Group randomized phase II trial (S1304) comparing twice weekly low-dose (27 mg/m2; arm 1) to high-dose carfilzomib (56 mg/m2; arm 2), both with dexamethasone, administered for 12 cycles (11 months) for relapsed and/or refractory multiple myeloma with up to six prior lines of therapy (NCT01903811). The primary endpoint was progression-free survival (PFS), and patients on arm 1 could cross-over to arm 2 after progression on treatment. Results: Among 143 enrolled patients, of whom 121 were eligible and analyzable, the overall response rate was 42.8%, with no significant difference between the arms (P = 0.113). Also, neither the median PFS [5 months and 8 months, respectively; HR, 1.061; 80% Wald confidence interval (CI), 0.821–1.370; P = 0.384] nor the median overall survival were significantly different (26 and 22 months, respectively; HR, 1.149, 80% Wald CI, 0.841–.571; P = 0.284). Sixteen patients crossed over to arm 2 with a median PFS benefit of 3 months. Certain adverse events (AE) were more frequent in arm 2, including fatigue, thrombocytopenia, and peripheral neuropathy, but there was no significant difference in cardiopulmonary AEs. Conclusions: This randomized trial did not support a benefit of fixed duration, twice weekly 56 mg/m2 dosing of carfilzomib over the 27 mg/m2 dose for the treatment of relapsed and/or refractory multiple myeloma. However, treatment to progression in earlier patient populations with high-dose carfilzomib using different schedules should still be considered as part of the standard of care.

Abstract Background: Race/ethnicity is associated with disparate incidence and outcomes in MM, as seen in population-based studies. Their effect on outcomes has not been reported in prospective studies. Obesity is the most consistently associated modifiable risk factor for MM and is influenced by race/ethnicity but its association with outcomes has not been explored. We analyzed patient-level data from published ECOG-ACRIN/SWOG clinical trials in newly diagnosed MM (NDMM) patients (pts) to explore the interplay of race/ethnicity, obesity and outcomes. Methods: Pooled data from 9 ECOG-ACRIN/SWOG clinical trials (E1A06, E4A03, E1A00, E2A02, E5A93, E9486, S0204, S0232, S9321) in NDMM (1988-2011) were analyzed. Pts were divided by race: White (W), African-American (AA), other (O); race/ethnicity: Hispanic (H), non-Hispanic White (NHW), non-Hispanic AA (NHAA), non-Hispanic other (NHO); and body mass index (BMI): <25, 25-29.9, ≥30. Associations between these and baseline pt/disease characteristics were assessed using chi-square (categorical) and Wilcoxon rank sum (continuous) tests. Survival distributions were estimated with Kaplan-Meier method and compared between groups using log-rank test. Cox proportional hazards regression was used to estimate hazard ratios in univariate and multivariate models. Time to event data was censored at 6 yrs. Results: Pt distribution by race, race/ethnicity and BMI is shown in Table 1. Race: AA were younger than W (median 59 vs 62 yr), had significantly more females (48% vs 40%; p=0.001) and had a smaller proportion of pts ≥70 yr (18% vs 26%; p<0.001). Median BMI was highest in AA (27.2) and lowest in O (24) (p=0.001) but not significantly different categorically between W and AA only (p=0.908). AA had significantly more pts with hemoglobin (Hb) ≤10 g/dL than W (55% vs 36%; p<0.001). Median creatinine (Cr) was 1.3 mg/dL in O and 1.1 mg/dL in W (p=0.03). There were no differences by race for ECOG performance status (PS), MM stage, lytic lesions, paraprotein subtype, serum calcium (Ca) or β2-microglobulin (β2M). Enrollment to clinical trials over years was significantly different by race (p=0.009). The only study design showing different enrollment by race was with/out stem cell transplant (SCT) (p=0.03; 37% of AA vs 31% of W got SCT trials). Race/Ethnicity: NHO were the youngest (median 58 yr) and NHW the oldest (median 62 yr) subgroup (p<0.001). NHAA had the highest proportion of pts with BMI ≥30 (16%) and NHO the lowest (7%) (p=0.018). H had the smallest proportion of females (33%) while NHO had the largest (54%) (p=0.002). H had the highest number of pts ≥70 yr (28%) and NHAA the smallest (18%) (p=0.003). Anemia rates were significantly different (p<0.001) with Hb ≤10 g/dL in 36% NHW vs 56% in NHAA. No significant differences were seen for PS, MM stage, lytic lesions, paraprotein subtype or other lab parameters. H and NHAA were enrolled in larger numbers in 1992-2011 rather than prior or later years (p<0.001). Among the subgroups, H had largest proportion of patients (75%) on trials without novel agent vs 61.5% for NHW (p=0.047). NHAA had the highest proportion of patients on trials with SCT (38%) while NHO had the smallest (27.3%) (p=0.034). BMI: By gender, 30% of males and 39% of females having BMI <25 (p<0.001). BMI <25 had the highest proportion of pts with ISS stage III (31%) vs 21.5% for ≥30 (p=0.001). A similar trend was seen for DS stage (p=0.005). 64% of ≥30 pts had Hb >10 while 51% of <25 did (p=0.003). There was significant difference in continuous Cr distribution by BMI (p=0.004). Efficacy analysis did not show any significant difference in response rate by race (p=0.132), race/ethnicity (p=0.286) or BMI (p=0.896). In univariate/multivariate analysis, significantly worse overall survival (OS) was seen in males, age ≥70 yr, ECOG PS >0, ISS and DS stage III, presence of lytic lesions, Cr ≥2 mg/dL, Ca >12 mg/dL, Hb ≤10 g/dL. No significant difference was seen in OS or progression free survival by race, race/ethnicity or BMI (Figure 1). Conclusions: Significant differences exist in demographic and clinical characteristics of NDMM pts by race/ethnicity. Median OS was significantly associated with these characteristics but not with race/ethnicity itself. Observed racial/ethnic disparity in outcomes for MM pts may be overcome by access to comparable therapeutic options as seen in clinical trials. Obesity, while associated with MM incidence, does not seem to influence outcomes. Figure 1 Figure 1. Disclosures Ailawadhi: Pharmacyclics: Consultancy; Novartis: Consultancy; Amgen Inc: Consultancy; Takeda Oncology: Consultancy. Stewart:Janssen Pharmaceuticals: Consultancy; Takeda Oncology: Consultancy; Celgene: Consultancy; Bristol Myers Squibb: Consultancy. Hussein:Celgene: Employment. Zonder:Takeda: Consultancy, Honoraria; Bristol Myers Squibb: Consultancy, Honoraria; Seattle Genetics: Consultancy, Honoraria; Celgene: Consultancy, Honoraria, Research Funding; Janssen: Consultancy, Honoraria; Pharmacyclics: Other: DSMC membership; Prothena: Consultancy, Honoraria. Barlogie:Mount Sinai Hospital: Employment.

Abstract Background: SWOG S0777, a randomized phase III trial, compared bortezomib, lenalidomide and dexamethasone (VRd) with lenalidomide and dexamethasone (Rd). The primary end point was progression-free survival (PFS) using a pre-specified one-sided stratified log rank test at a significance level of 0.02. The stratification factors were International Staging System (ISS) stage (I, II or III) and intent to transplant (yes or no), among a total of 6 strata. Overall response rate (ORR), overall survival (OS) and safety were secondary end points. Results of the primary analysis of this trial were published in Lancet (2016, Volume 389, Issue 10068, 519 - 527). Methods: This updated analysis includes 460 patients evaluable for survival endpoints: 225 eligible and analyzable patients were randomized to Rd and 235 patients to VRd. Rd patients received lenalidomide 25 mg/day on days 1-21 and dexamethasone 40 mg/day on days 1, 8, 15 and 22 of a 28-day cycle. VRd patients received lenalidomide 25 mg/day on days 1-14 and dexamethasone 20/mg/day on days 1, 2, 4, 5, 8, 9, 11 and 12 plus bortezomib 1.3 mg/m2 IV push on days 1, 4, 8 and 11 of a 21-day cycle. All patients received aspirin 325 mg/day and VRd patients received VZV prophylaxis per institutional standard. The 6-month induction was six 28-day cycles of Rd and eight 21-day cycles of VRd followed by Rd maintenance for all patients until progression, unacceptable toxicity or withdrawal of consent. Results: Between 2008 and 2012, 525 patients from 48 institutions were randomized. Patient data have been rigorously updated for this analysis based upon a May 15, 2018 datalock. The median follow up is now 84 months (7 years). The median PFS is 41 months for VRd and 29 months for Rd: stratified hazard ratio (96% Wald Confidence Interval) was 0.742 (0.594, 0.928) and one-sided stratified log-rank P-value 0.003 (see Figure 1). The median OS for VRd is still not reached with median OS for Rd being 69 months: stratified hazard ratio (96% Wald Confidence Interval) was 0.709 (0.543, 0.926) and stratified two-sided P-value was 0.0114 (see Figure 2). The impact of age was assessed in several ways including using 3 cutoffs (<65 years; 65-75 years; >75 years) and multivariate cox proportional hazards regression analyses adjusted for age. As in prior analyses, both PFS and OS were improved with VRd versus Rd adjusting for age (P-values: 0.013 [PFS]; 0.033 [OS])). Depth of response was assessed incorporating new serial data and additional bone marrow results. The CR plus VGPR was 74.9% for VRd versus CR plus VGPR of 53.7% for Rd (P-value 0.006 for response differences using a stratified Cochran-Mantel- Haenszel analysis). The median duration of lenalidomide plus dexamethasone maintenance was 17.4 months. The number of second cancers was 19/235 (8%) with VRd and 16/225 (7%) with Rd. Conclusion: The addition of bortezomib to lenalidomide dexamethasone for induction therapy in previously untreated myeloma results in a statistically significant and clinically meaningful improvement in PFS as well as better OS with follow up of 7 years. VRd had an acceptable safety and tolerability profile and continues to represent an appropriate standard of care irrespective of age. Disclosures Durie: Takeda: Consultancy; Amgen: Consultancy; Celgene: Consultancy; Johnson & Johnson: Consultancy. Abidi:Millenium Takeda: Research Funding. Epstein:University of Arkansas for Medical Sciences: Employment. Dispenzieri:Celgene, Takeda, Prothena, Jannsen, Pfizer, Alnylam, GSK: Research Funding. Reu:Bristol Myers Squibb: Employment; Millenium Takeda: Consultancy; Novartis: Consultancy, Research Funding; Celgene: Research Funding. Orlowski:Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees; Millenium Pharmaceuticals: Consultancy, Research Funding; Amgen: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; BioTheryX, Inc: Consultancy, Membership on an entity's Board of Directors or advisory committees; Genentech: Consultancy; Janssen Pharmaceuticals: Consultancy, Membership on an entity's Board of Directors or advisory committees; Poseida: Research Funding; Bristol Myers Squibb: Consultancy. Barlogie:Dana Farber Cancer Institute: Other: travel stipend; Celgene: Consultancy, Research Funding; International Workshop on Waldenström's Macroglobulinemia: Other: travel stipend; Multiple Myeloma Research Foundation: Other: travel stipend; European School of Haematology- International Conference on Multiple Myeloma: Other: travel stipend; Myeloma Health, LLC: Patents & Royalties: : Co-inventor of patents and patent applications related to use of GEP in cancer medicine licensed to Myeloma Health, LLC; ComtecMed- World Congress on Controversies in Hematology: Other: travel stipend; Millenium: Consultancy, Research Funding.

Abstract Background: Lenalidomide with dexamethasone (Rd) is a standard of care for patients with previously untreated multiple myeloma. SWOG S0777, a randomized phase III trial, has compared Rd with bortezomib, lenalidomide and dexamethasone (VRd). The primary end point is progression-free survival (PFS) using a pre-specified one-sided stratified log rank test at a significance level of 0.02. The stratification factors are International Staging System (ISS) stage (I, II or III) and intent to transplant (yes or no), a total of 6 strata. Overall response rate (ORR), overall survival (OS) and safety are secondary end points. Methods: This analysis includes 474 patients evaluable for survival endpoints: 232 patients were randomized to Rd and 242 patients to VRd. Rd patients received lenalidomide 25 mg/day on days 1-21 and dexamethasone 40 mg/day on days 1, 8, 15 and 22 of a 28-day cycle. VRd patients received lenalidomide 25 mg/day on days 1-14 and dexamethasone 20/mg/day on days 1, 2, 4, 5, 8, 9, 11 and 12 plus bortezomib 1.3 mg/m2 IV push on days 1, 4, 8 and 11 of a 21-day cycle. All patients received aspirin 325 mg/day and VRd patients received HSV prophylaxis per institutional standard. Induction was six 28-day cycles of Rd and eight 21-day cycles of VRd followed by Rd maintenance for all patients until progression, unacceptable toxicity or withdrawal of consent. Initial analyses utilized the pre-specified one-sided stratified log rank test. Results: Data are presented for VRd followed by Rd throughout. Between 2008 and 2012, 525 patients from 48 institutions were randomized. Fifty-one patients, 29 randomized to Rd and 22 randomized to RVd, were ineligible for the following reasons: missing, insufficient or early or late baseline labs (40); not meeting requirements of measurable disease (6); inadequate marrow function (1); inadequate creatinine clearance (1); prior malignancy (1); prior therapy (1); and more than 2 weeks of prior steroid therapy (1). The pre-specified significance level of 0.02 was reached in the log rank testing. The stratified hazard ratio (HR) was 0.742 (96% Wald confidence interval: 0.579, 0.951), and the one-sided stratified log rank p-value for PFS (VRd vs. Rd) was 0.0066. The OS was improved for VRd vs. Rd with HR = 0.666; two-sided log-rank p-value = 0.0114. The PFS and OS survival charts are displayed below. Median PFS was 43 months (VRd) versus 31 months (Rd). Median OS was not reached (VRd) versus 63 months (Rd). Patient characteristics were well-matched between VRd and Rd with the exception of fewer women (37% vs. 47%: P = 0.033) and fewer older patients (≥ 65 years 38% vs. 48%: P = 0.042) receiving VRd. With univariate Cox regression analysis correlates of better PFS/OS were: use of VRd (HR 0.72/0.65; P = 0.006); hemogoblin ≥10 g/dl (HR 1.17/1.43; P = 0.2/0.026) and lower ISS disease stage (HR 1.35/1.98; P = 0.014/< 0.001). The ORR for VRd was 71.07% versus 63.79% for Rd. The adverse events by CTC category and toxicity category were fairly well balanced. The most common hematologic adverse events (≥ Grade 3 and at least possibly attributable to therapy) were low hemoglobin (RVd=13%; Rd=16%), leukopenia (RVd=14%; Rd=16%), lymphopenia (RVd=23%; Rd=18%), neutropenia (RVd=19%; Rd=21%), and thrombocytopenia (RVd=18%; Rd=14%). The most common non-hematologic adverse events (≥ Grade 3 and at least possibly attributable to therapy) were: fatigue (RVd=16%; Rd=14%), sensory neuropathy (RVd=23%; Rd=3%), hyperglycemia (RVd=7%; Rd=11%), thrombosis/embolism (RVd=8%; Rd=9%), hypokalemia (RVd=9%; Rd=6%), muscle weakness (RVd=7%; Rd=4%), diarrhea (RVd=8%; Rd=2%), and dehydration (RVd=8%; Rd=2%). As expected ≥ Grade 3 neuropathy was more frequent with VRd (24% vs. 5%: P < 0.0001). Sixteen patients experienced a second primary malignancy, 7 (3%) on VRd and 9 (4%) on Rd. Conclusion: The addition of bortezomib to lenalidomide dexamethasone for induction therapy in previously untreated myeloma results in a statistically significant and clinically meaningful improvement in PFS as well as better OS. VRd had an acceptable safety and tolerability profile despite increased neurotoxicity and represents a potential new standard of care. Support: NIH/NCI/NCTN grants CA180888, CA180819, CA180821, CA180820; and in part by Millennium Pharmaceuticals, Inc., The Takeda Oncology Company, for provision of study drug. Figure 1. Figure 1. Figure 2. Figure 2. Disclosures Durie: Johnson & Johnson: Consultancy; Takeda: Consultancy; Onyx: Consultancy; Celgene: Consultancy. Abidi:Millennium: Research Funding. Epstein:University of Arkansas for Medical Sciences: Employment. Reu:Takeda/Millennium: Research Funding; Novartis: Research Funding; Celgene: Research Funding. Orlowski:BioTheryX, Inc.: Membership on an entity's Board of Directors or advisory committees; Janssen Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees; Celgene: Consultancy, Research Funding; Spectrum Pharmaceuticals: Research Funding; Onyx Pharmaceuticals: Consultancy, Research Funding; Bristol-Myers Squibb: Consultancy, Research Funding; Millennium Pharmaceuticals: Consultancy, Research Funding; Acetylon: Membership on an entity's Board of Directors or advisory committees; Genentech: Consultancy; Forma Therapeutics: Consultancy; Array BioPharma: Consultancy, Research Funding. Barlogie:Dana Farber Cancer Institute: Other: Travel Stipend; International Workshop on Waldenström's Macroglobulinemia: Other: Travel Stipend; ComtecMed- World Congress on Controversies in Hematology: Other: Travel Stipend; European School of Haematology- International Conference on Multiple Myeloma: Other: Travel Stipend; Celgene: Consultancy, Research Funding; Millennium: Consultancy, Research Funding; Myeloma Health, LLC: Patents & Royalties: Co-inventor of patents and patent applications related to use of GEP in cancer medicine licensed to Myeloma Health, LLC; Multiple Myeloma Research Foundation: Other: Travel Stipend.

Abstract BACKGROUND: The introduction of novel agents and proteasome inhibitors, and advances in high dose therapy administration has made an impact on the survival outcomes for MM patients. However, HRMM still remains a therapeutic challenge with poor prognosis. Even with aggressive approaches such as the Total Therapy protocols, patients with poor genomic risk have a 2-year event-free survival of ~50% (Nair et al, Blood 2010). A randomized Phase I/II trial was designed to evaluate the efficacy of adding immunotherapy into the first line for HRMM patients, comparing lenalidomide, bortezomib and dexamethasone (RVD) with or without addition of elotuzumab (Elo), a humanized monoclonal antibody that binds to SLAMF7/CS1. We are reporting on the Phase I portion of the study. PATIENTS & METHODS: The objective of Phase I was to determine the maximum tolerated dose (MTD) of RVD-Elo. Both low/standard risk MM and HRMM patients were eligible. HRMM was defined by one or more of the following: (1) poor risk genomics by the Arkansas 70-gene model, (2) translocation (14;16), translocation (14;20) and/or deletion (17p) by florescent in-situ hybridization (FISH), (3) primary plasma cell leukemia and (4) serum LDH > 2 times normal levels. The treatment consisted of induction chemotherapy for 8 cycles with RVD-Elo (lenalidomide 25 mg orally days 1-14 of every 21-day cycle; bortezomib 1.3 mg/m2 subcutaneously days 1,4,8,11; dexamethasone 20 mg orally days 1,2,4,5,8,9,11,12; elotuzumab 10 mg/kg intravenously days 1,8,15 cycles 1-2 then days 1,11 cycles 3-8) followed by dose-attenuated RVD-Elo maintenance (lenalidomide 25 mg orally days 1-14; bortezomib 1.0 mg/m2 subcutaneously days 1,8,15; dexamethasone 12 mg orally days 1,8,15; elotuzumab 10 mg/kg intravenously days 1,15) until disease relapse, progression or intolerance. Adverse events (AE) were recorded as per the NCI CTCAEv4.0. RESULTS: Eight newly diagnosed MM patients were enrolled on the Phase I run-in study. Six patients (Figure 1) were evaluable for dose limiting toxicities (DLT) during Cycle 1 as per protocol. The median age of patients was 67 years (range: 56-79 years), with 67% ≥65 years, Hgb was less than 10 g/dL in 50%, creatinine was greater than 2 mg/dL in all patients. ISS stage distribution was 17% (I), 33% (II) and 50% (III). Deletion 13 was observed in 1 patient (17%). The most common AEs (all grades) were fatigue (100%), peripheral sensory neuropathy (83%), edema (83%), lymphopenia (66%) and leukopenia (50%). The most common Grade 3 AEs were peripheral sensory neuropathy (33%), one of which was a DLT, neutropenia (17%) and thrombocytopenia (17%). One Grade 4 lymphopenia was observed. All 6 patients have completed 8 cycles of RVD-Elo induction therapy and 5 patients have completed at least 4 cycles of RVD-Elo maintenance. Overall median days on therapy per cycle were 13 days during induction and 20 days per cycle during maintenance. Dose adjustments were made in 83% of patients for bortezomib, 83% for lenalidomide and 33% for dexamethasone. There were no dose reductions for elotuzumab, although three patients had 1 event each of dose delays/missed dosing attributable to AE/SAE from RVD. Efficacy data will be released at the time that the phase II study of RVD +/- Elo is mature. Discussion/Conclusion: The RVD-Elo is a safe well-tolerated regimen for newly diagnosed MM patients without major additive AE/SAE beyond what is already known about RVD. This is the first report of the only phase I experience combining the triple-drug regimen RVD with the monoclonal antibody Elotuzumab for newly diagnosed MM. Support: NCI grants CA32102, CA38926, CA180821, CA31946, CA21076, CA180799, CA21115, CA180820 and in part by Bristol-Myers Squibb Company Disclosures Usmani: Celgene Corporation: Consultancy, Honoraria, Research Funding; Millennium: Consultancy, Honoraria; Onyx: Consultancy, Honoraria, Research Funding; Sanofi: Consultancy; Array BioPharma: Research Funding; Janssen: Research Funding; Pharmacyclics: Research Funding. Off Label Use: Lenalidomide in newly diagnosed multiple myeloma patients. Ailawadhi:Millennium: Honoraria. Shah:Onyx Pharmaceuticals: Consultancy, Research Funding; Celgene: Consultancy, Research Funding; Millennium Pharmaceuticals: Consultancy, Research Funding; Novartis: Consultancy, Research Funding; Array: Consultancy, Research Funding. Rosenzweig:Celgene: Speakers Bureau. Durie:IRC J&J: Membership on an entity's Board of Directors or advisory committees; Celgene Corp: Expert Board Committee Other; IRC Onyx: Membership on an entity's Board of Directors or advisory committees; DMC Millennium: Membership on an entity's Board of Directors or advisory committees. Orlowski:Bristol-Myers Squibb: Membership on an entity's Board of Directors or advisory committees, Research Funding; Onyx Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees, Research Funding; Millennium: The Takeda Oncology Company: Membership on an entity's Board of Directors or advisory committees, Research Funding; Spectrum Pharmaceuticals: Research Funding; JW Pharmaceutical: Research Funding; Array BioPharma: 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; Novartis: Membership on an entity's Board of Directors or advisory committees; Janssen Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees.