Orlowski, Robert Z.

Abstract Introduction: In oncology clinical trials, overall survival (OS) is considered the gold standard efficacy endpoint. However, in multiple myeloma, the prolonged survival times and availability of multiple salvage therapies render it difficult to rely on OS as a primary endpoint. Instead, progression-free survival (PFS) or clinical response can be a relevant biomarker. At the same time, some health technology assessment bodies will only consider evidence based on patient-relevant endpoints, such as morbidity, mortality, and health-related quality of life (HRQoL), within their benefit assessments. Patient-reported outcomes (PROs) provide insights into how a treatment affects HRQoL, including symptoms and functioning. In the phase 3 MAIA trial, daratumumab, lenalidomide, and dexamethasone (D-Rd) demonstrated a significantly prolonged PFS and rapid and sustained improvements in PROs compared with lenalidomide and dexamethasone (Rd) alone at a median follow-up of 28 months. Updated results with longer follow-up confirmed a continued PFS benefit, deepening best clinical responses, and a significant OS benefit with D-Rd. Here, we report the results of analyses exploring the relationship between clinical efficacy endpoints and PROs in the MAIA trial. Methods: In MAIA (NCT02252172), TIE patients with NDMM were randomized to D-Rd or Rd until disease progression (PD) or unacceptable side effects. Clinical response and PD were defined per the International Myeloma Working Group uniform response criteria. PROs were assessed at baseline, on day 1 of cycles 3, 6, 9, and 12 for year 1, every 6 months thereafter until PD, or at end of treatment and at 8 and 16 weeks post-progression using the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire Core 30-item (EORTC QLQ-C30). The current analyses were conducted on patients with a baseline PRO assessment and ≥1 post-baseline PRO assessment using a clinical cutoff date of February 19, 2021. Patients from both treatment groups were pooled and stratified by best clinical response. For PROs, the threshold for clinically meaningful change from baseline was defined a priori as ≥10 points based on published literature. Analyses were conducted for the global health status (GHS), fatigue, and pain scales of the EORTC QLQ-C30. The proportions of patients with clinically meaningful improvement in these PROs from baseline at any time while on treatment were calculated for and compared across best clinical response subgroups. For this analysis, patients were censored at the time of PD or discontinuation of therapy. Results were summarized with odds ratios and 95% confidence intervals. Additionally, the proportions of patients with clinically meaningful worsening in PROs from baseline at the time of and post-progression were also calculated for those who had PD. No adjustments were made for multiplicity. Nominal P-values are presented. Results: Best clinical response at a median follow-up of 56.2 months for the 710 patients included in this analysis is shown in the Table. For GHS, fatigue, and pain, the proportion of patients who reported clinically meaningful improvement from baseline increased with increasing depth of best clinical response. Odds ratios comparing best clinical response vs stable disease reflect this relationship and are shown in the Figure. Of the 264 patients who experienced PD and had PRO data at the time of or post-progression, 38.6%, 54.9%, and 39.4% reported meaningful worsening of GHS, pain, and fatigue, respectively, at the time of or post-progression. Conclusions: Patients with deeper best clinical response were more likely to report meaningful improvements in PROs. Patients who experienced PD reported worsening of GHS and symptoms at the time of or following progression. These analyses provide evidence of the association between key clinical efficacy endpoints and PROs and demonstrate the patient relevance of these clinical endpoints. Figure 1 Figure 1. Disclosures Perrot: Abbvie: Honoraria; BMS Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees; GSK: Honoraria, Membership on an entity's Board of Directors or advisory committees; Sanofi: Honoraria, Research Funding; Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Kumar: Amgen: Consultancy, Research Funding; BMS: Consultancy, Research Funding; KITE: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Research Funding; Astra-Zeneca: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Merck: Research Funding; Abbvie: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Roche-Genentech: Consultancy, Research Funding; Bluebird Bio: Consultancy; Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Carsgen: Research Funding; Antengene: Consultancy, Honoraria; Oncopeptides: Consultancy; Beigene: Consultancy; Tenebio: Research Funding; Takeda: Consultancy, 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; Adaptive: Membership on an entity's Board of Directors or advisory committees, Research Funding; Sanofi: Research Funding. Plesner: Takeda: Research Funding; Genentech: Other: Advisor, Research Funding; Oncopeptides: Other: Advisor, Research Funding; AbbVie: Other: Advisor, Research Funding; CSL Behring: Other: Advisor; Janssen: Other: Advisor, Research Funding; Celgene: Other: Advisor, Research Funding; Genmab: Research Funding. Orlowski: Asylia Therapeutics, Inc., BioTheryX, Inc., and Heidelberg Pharma, AG.: Other: Laboratory research funding; CARsgen Therapeutics, Celgene, Exelixis, Janssen Biotech, Sanofi-Aventis, Takeda Pharmaceuticals North America, Inc.: Other: Clinical research funding; Amgen, Inc., BioTheryX, Inc., Bristol-Myers Squibb, Celgene, EcoR1 Capital LLC, Genzyme, GSK Biologicals, Janssen Biotech, Karyopharm Therapeutics, Inc., Neoleukin Corporation, Oncopeptides AB, Regeneron Pharmaceuticals, Inc., Sanofi-Aventis, and Takeda P: Consultancy, Honoraria; Asylia Therapeutics, Inc.: Current holder of individual stocks in a privately-held company, Patents & Royalties; Amgen, Inc., BioTheryX, Inc., Bristol-Myers Squibb, Celgene, Forma Therapeutics, Genzyme, GSK Biologicals, Janssen Biotech, Juno Therapeutics, Karyopharm Therapeutics, Inc., Kite Pharma, Neoleukin Corporation, Oncopeptides AB, Regeneron Pharmaceuticals, I: Membership on an entity's Board of Directors or advisory committees. Moreau: Abbvie: Honoraria; Oncopeptides: Honoraria; Celgene BMS: Honoraria; Sanofi: Honoraria; Amgen: Honoraria; Janssen: Honoraria. Bahlis: Amgen: Consultancy, Honoraria; Janssen: Consultancy, Honoraria; Abbvie: Consultancy, Honoraria; Pfizer: Consultancy, Honoraria; Sanofi: Consultancy, Honoraria; BMS/Celgene: Consultancy, Honoraria; Karyopharm: Consultancy, Honoraria; Takeda: Consultancy, Honoraria; Genentech: Consultancy; GlaxoSmithKline: Consultancy, Honoraria. Nahi: XNK Therapeutics AB: Consultancy. Hulin: abbvie: Honoraria; Celgene/BMS: Honoraria; Sanofi: Honoraria; Takeda: Honoraria; Janssen: Honoraria. Quach: Bristol Myers Squibb: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; CSL: Consultancy, Membership on an entity's Board of Directors or advisory committees; Janssen/Cilag: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; GlaxoSmithKline: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Antengene: 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, Research Funding; Karyopharm: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Takeda: Consultancy, Membership on an entity's Board of Directors or advisory committees; Sanofi: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding. Goldschmidt: GSK: Honoraria; Incyte: Research Funding; Janssen: Consultancy, Honoraria, Other: Grants and/or Provision of Investigational Medicinal Product, Research Funding; Amgen: Consultancy, Honoraria, Other: Grants and/or Provision of Investigational Medicinal Product, Research Funding; BMS: Consultancy, Honoraria, Other: Grants and/or Provision of Investigational Medicinal Product, Research Funding; Adaptive Biotechnology: Consultancy; Celgene: Consultancy, Honoraria, Other: Grants and/or Provision of Investigational Medicinal Product, Research Funding; Chugai: Honoraria, Other: Grants and/or Provision of Investigational Medicinal Product, Research Funding; Novartis: Honoraria, Research Funding; Dietmar-Hopp-Foundation: Other: Grant; Sanofi: Consultancy, Honoraria, Other: Grants and/or Provision of Investigational Medicinal Product, Research Funding; Takeda: Consultancy, Research Funding; Johns Hopkins University: Other: Grant; Mundipharma: Research Funding; MSD: Research Funding; Molecular Partners: Research Funding. O'Dwyer: Bristol Myers Squibb: Research Funding; ONK Therapeutics: Current Employment, Current equity holder in publicly-traded company, Membership on an entity's Board of Directors or advisory committees; Janssen: Consultancy. Venner: Amgen: Research Funding; Celgene: Research Funding; Takeda: Honoraria; Amgen: Honoraria; Janssen: Honoraria; BMS: Honoraria; Sanofi: Honoraria; Pfizer: Honoraria. Weisel: Adaptive Biotechnologies: 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, Research Funding; Takeda: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Roche: Honoraria; Sanofi: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Karyopharm: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; GSK: 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, Research Funding; Oncopeptides: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Abbvie: Consultancy; Novartis: Honoraria; Pfizer: Honoraria. Raje: Celgene, Amgen, Bluebird Bio, Janssen, Caribou, and BMS: Other. Macro: Takeda: Honoraria, Other: Travel accomodation, Research Funding; Janssen: Honoraria, Other: Travel accomodation, Research Funding; GSK: Honoraria; Celgen/BMS: Honoraria; Sanofi: Honoraria. Leleu: Sanofi: Honoraria; Roche: Honoraria; Pierre Fabre: Honoraria; Oncopeptides: Honoraria; Novartis: Honoraria; Mundipharma: Honoraria; Merck: Honoraria; Karyopharm Therapeutics: Honoraria; Amgen: Honoraria; Bristol-Myers Squibb: Honoraria; Carsgen Therapeutics Ltd: Honoraria; Celgene: Honoraria; Gilead Sciences: Honoraria; Janssen-Cilag: Honoraria; AbbVie: Honoraria; Takeda: Honoraria, Other: Non-financial support. Liu: Janssen: Current Employment, Current equity holder in publicly-traded company. Fastenau: Janssen: Current Employment, Current equity holder in publicly-traded company. Gries: Janssen: Current Employment, Current holder of individual stocks in a privately-held company. Ho: DRG Abacus: Consultancy; Emalex Biosciences: Consultancy; Janssen: Consultancy. Mistry: Janssen: Current Employment, Current equity holder in publicly-traded company. Tromp: Janssen: Current Employment, Current equity holder in publicly-traded company. Delioukina: Janssen: Current Employment. Vermeulen: Janssen: Current Employment, Current equity holder in publicly-traded company. Usmani: Amgen: Consultancy, Research Funding, Speakers Bureau; Abbvie: Consultancy; Array BioPharma: Consultancy, Research Funding; GSK: Consultancy, Research Funding; EdoPharma: Consultancy; SkylineDX: Consultancy, Research Funding; Celgene/BMS: Consultancy, Research Funding, Speakers Bureau; Takeda: Consultancy, Research Funding, Speakers Bureau; Seattle Genetics: Consultancy, Research Funding; Pharmacyclics: Consultancy, Research Funding; Merck: Consultancy, Research Funding; Janssen: Consultancy, Research Funding, Speakers Bureau; Sanofi: Consultancy, Research Funding, Speakers Bureau; Janssen Oncology: Consultancy, Research Funding; Bristol-Myers Squibb: Research Funding.

Background: Isatuximab (SAR650984) is an IgG1k monoclonal antibody that binds with high affinity to CD38 expressed on plasma cells in AL amyloidosis. It has been shown to be efficacious and well tolerated in relapsed and refractory multiple myeloma as a single agent and in combination. Here we report on the preliminary results of a prospective multi-center, phase II study of isatuximab in previously treated patients with AL amyloidosis (NCT03499808). Methods: Eligibility included age ≥ 18 years, relapsed or refractory systemic AL amyloidosis, ≥ 1 prior line of therapy, measurable disease (defined as a positive monoclonal serum immunofixation electrophoresis (IFE) or urine IFE, a serum free light chain ratio outside of the normal range (0.25-1.65), and a difference in the involved versus the uninvolved serum free light chain of ≥ 4.5 mg/dL), at least one organ involved, not refractory to daratumumab, ECOG performance status 0-2, creatinine clearance ≥25 mL/min as measured by 24-hour urine collection or as estimated by Cockcroft and Gault formula, and NT-proBNP ≤8500 pg/mL. Patients received isatuximab intravenously 20 mg/kg weekly during the first 28 day cycle and every other week during cycles 2 through 24 for a maximum of 24 cycles. The primary objective was hematologic response with secondary objectives of organ response, safety, progression free survival, and overall survival. Results: At data cut-off (July 24, 2020), 43 patients were registered from March 2018 to September 2019 at 14 institutions. Thirty six patients were eligible with 35 patients receiving at least one dose of isatuximab. Of the eligible patients, the median age was 70 (range 40-81). Prior therapies included proteasome inhibitors in 32 patients (89%), high dose therapy followed by autologous stem cell transplant in 17 patients (47%), immunomodulatory therapy in 9 patients (25%), and anti-CD38 monoclonal antibody therapy in 2 patients (6%). Single organ system involvement was seen in 19 patients (53%), ≥ 2 organ systems in 17 patients (47%), 16 patients (44%) had renal involvement, and 24 (67%) had cardiac involvement. For those with cardiac involvement, 7 patients (29%) had cardiac biomarker stage II and 9 patients (38%) had stage III disease using the Revised Mayo Staging (Kumar S et al., J Clin Oncol, 2012). A total of 17 patients remain on therapy. The median duration on treatment for eligible patients is currently 11.8 months (current range, 0.3-22.1). Of the 19 patients who discontinued treatment, the most common reasons included adverse events in 5 patients (26%), disease progression in 4 patients (21%), sub-optimal response in 2 patients (11%), and concerns related to COVID-19 in 2 patients (11%). The current median follow up is 16.3 months. The most common drug-related AEs were infusion related reactions in 18 patients (50%) with the majority (16/18) being grade I or II, anemia in 9 patients (25%) with the majority (8/9) being grade I, and lymphopenia in 8 patients (22%). Patient characteristics and preliminary safety data were previously presented at the International Symposium on Amyloidosis. The overall hematologic response rate was 77%. Hematological complete response (CR) was observed in 1 of 35 evaluable (completing at least 1 dose) patients (3%), very-good-partial response (VGPR) in 19 patients (54%), and partial response (PR) in 7 patients (20%). Conclusions: Isatuximab demonstrates encouraging efficacy in previously treated patients with AL amyloidosis. The administration of isatuximab in these patients is associated with a good safety profile similar to other monoclonal antibodies against CD38. The data will be updated at the meeting. Disclosures Sanchorawala: Prothena: Research Funding; Caelum: Research Funding; Oncopeptide: Research Funding; Janssen: Research Funding; Regeneron: Other: advisory board; Caleum: Other: advisory board; Proclara: Other: advisory board; Abbvie: Other: advisory board; UpToDate: Patents & Royalties; Takeda: Research Funding; Celgene: Research Funding. Kapoor:Sanofi: Consultancy, Research Funding; Celgene: Honoraria; Cellectar: Consultancy; Janssen: Research Funding; Amgen: Research Funding; GlaxoSmithKline: Research Funding; Takeda: Honoraria, Research Funding. Neparidze:GlaxoSmithKline: Research Funding; Janssen: Research Funding; Sanofi: Membership on an entity's Board of Directors or advisory committees, Other: Advisory board; Eidos Therapeutics: Membership on an entity's Board of Directors or advisory committees, Other: Diagnostic committee member . Sarosiek:Spectrum: Research Funding. Durie:Amgen, Celgene, Johnson & Johnson, and Takeda: Consultancy. Usmani:Incyte: Research Funding; Takeda: Consultancy, Honoraria, Other: Speaking Fees, Research Funding; Sanofi: Consultancy, Honoraria, Research Funding; Janssen: Consultancy, Honoraria, Other: Speaking Fees, Research Funding; SkylineDX: Consultancy, Research Funding; Merck: Consultancy, Research Funding; Array Biopharma: Research Funding; Pharmacyclics: Research Funding; Celgene: Other; Seattle Genetics: Consultancy, Research Funding; GSK: Consultancy, Research Funding; BMS, Celgene: Consultancy, Honoraria, Other: Speaking Fees, Research Funding; Amgen: Consultancy, Honoraria, Other: Speaking Fees, Research Funding; Abbvie: Consultancy. Orlowski:Laboratory research funding from BioTheryX, and clinical research funding from CARsgen Therapeutics, Celgene, Exelixis, Janssen Biotech, Sanofi-Aventis, Takeda Pharmaceuticals North America, Inc.: Research Funding; STATinMED Research: Consultancy; Founder of Asylia Therapeutics, Inc., with associated patents and an equity interest, though this technology does not bear on the current submission.: Current equity holder in private company, Patents & Royalties; Sanofi-Aventis, Servier, Takeda Pharmaceuticals North America, Inc.: Honoraria, Membership on an entity's Board of Directors or advisory committees; Amgen, Inc., AstraZeneca, BMS, Celgene, EcoR1 Capital LLC, Forma Therapeutics, Genzyme, GSK Biologicals, Ionis Pharmaceuticals, Inc., Janssen Biotech, Juno Therapeutics, Kite Pharma, Legend Biotech USA, Molecular Partners, Regeneron Pharmaceuticals, Inc.,: Honoraria, Membership on an entity's Board of Directors or advisory committees. OffLabel Disclosure: Isatuximab is FDA approved for relapsed refractory myeloma in combination with pomalidomide and dexamethasone. Isatuximab is not FDA approved for AL amyloidosis.

PURPOSE To evaluate the effects of daratumumab, lenalidomide, and dexamethasone (D-Rd) versus lenalidomide and dexamethasone (Rd) on patient-reported outcomes (PROs) in the phase III MAIA study. PATIENTS AND METHODS PROs were assessed on the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire Core 30-item and the EuroQol 5-dimensional descriptive system at baseline and every 3 months during treatment. By mixed-effects model, changes from baseline are presented as least squares means with 95% CIs. RESULTS A total of 737 transplant-ineligible (TIE) patients with newly diagnosed multiple myeloma were randomly assigned to D-Rd (n = 368) or Rd (n = 369). Compliance with PRO assessments was high at baseline (> 90%) through month 12 (> 78%) for both groups. European Organization for Research and Treatment of Cancer Quality of Life Questionnaire Core 30-item global health status scores improved from baseline in both groups and were consistently greater with D-Rd at all time points. A global health status benefit was achieved with D-Rd, regardless of age (< 75 and ≥ 75 years), baseline Eastern Cooperative Oncology Group (ECOG) performance status score, or depth of response. D-Rd treatment resulted in significantly greater reduction in pain scores as early as cycle 3 ( P = .0007 v Rd); the magnitude of change was sustained through cycle 12. Reductions in pain with D-Rd were clinically meaningful in patients regardless of age, ECOG status, or depth of response. Similarly, PRO improvements were observed with D-Rd and Rd on the EuroQol 5-dimensional descriptive system visual analog scale score. CONCLUSION D-Rd compared with Rd was associated with faster and sustained clinically meaningful improvements in PROs, including pain, in transplant-ineligible patients with newly diagnosed multiple myeloma regardless of age, baseline ECOG status, or depth of treatment response.

Introduction: Daratumumab (DARA) is a human, CD38-targeting, IgG1κ monoclonal antibody approved as monotherapy in relapsed/refractory multiple myeloma (RRMM) and in combination with standard of care for RRMM and NDMM. The addition of DARA to standard-of-care regimens in phase 3 studies has consistently improved progression-free survival (PFS) and led to deep and durable responses, including higher rates of minimal residual disease (MRD) negativity compared with standard of care. In the primary analysis of the phase 3 MAIA study (median follow-up, 28.0 mo), D-Rd vs Rd significantly improved PFS and MRD-negativity rates in transplant-ineligible NDMM (Facon T, N Engl J Med 2019). With longer follow-up (36.4 mo), D-Rd maintained a PFS benefit and deeper and more durable responses vs Rd alone (Bahlis N, Blood 2019. 134[Suppl 1]:1875). Here, we report updated efficacy and safety findings from MAIA after approximately 4 years of follow-up. Methods: Patients with NDMM ineligible for high-dose chemotherapy and autologous stem cell transplantation due to age ≥65 years or comorbidities were randomly assigned (1:1) to receive Rd ± DARA. Stratification factors included International Staging System stage (ISS [I vs II vs III]), region (North America vs other), and age (&lt;75 vs ≥75 years). All patients received 28-day cycles of Rd (R: 25 mg orally once daily on Days 1-21; d: 40 mg orally on Days 1, 8, 15 and 22). In the D-Rd arm, DARA (16 mg/kg intravenously) was given weekly for Cycles 1-2, every 2 weeks in Cycles 3-6, and every 4 weeks thereafter. Patients were treated until disease progression or unacceptable toxicity in both treatment arms. The primary endpoint was PFS. Key secondary endpoints included overall response rate (ORR), MRD-negativity rate (10‒5 sensitivity, clonoSEQ® version 2.0), and safety. PFS on the next line of therapy (PFS2), defined as the time from randomization to progression on the next subsequent line of therapy or death, was also measured. Results: A total of 737 patients were randomized (D-Rd, n = 368; Rd, n = 369). Patient baseline characteristics were well balanced between the two treatment arms. Median (range) age was 73 (45-90) years, with 44% of patients ≥75 years of age. 27%, 43%, and 29% of all patients were ISS stage I, II, and III, respectively. Among 642 patients evaluable for FISH/karyotyping analysis, 86% had standard and 14% had high cytogenetic risk. After a median follow-up of 47.9 months, 176 (48%) and 273 (75%) patients discontinued study treatment in the D-Rd vs Rd groups, respectively, with 85 (23%) and 113 (31%) patients discontinuing treatment due to progressive disease. PFS remained improved for D-Rd vs Rd (median, not reached [NR] vs 34 mo; HR, 0.54; 95% CI, 0.43-0.67; P&lt;0.0001; Figure). The estimated 48-month PFS rate was 60% with D-Rd vs 38% with Rd. The PFS benefit of D-Rd in prespecified subgroups, including patients with high cytogenetic risk, was generally consistent with overall results. Adding DARA to Rd continued to result in deeper responses with higher rates of ≥CR and ≥very good partial response (VGPR; Table). Median duration of response among responders was NR with D-Rd vs 44 months with Rd. Median PFS2 was NR vs 51 months with D-Rd vs Rd, respectively (HR, 0.65; 95% CI, 0.52-0.83; P=0.0005); follow up is ongoing. 107 (29%) patients in the D-Rd group and 132 (36%) in the Rd group have discontinued the study due to death. Grade 3/4 treatment-emergent adverse events (TEAEs; D-Rd/Rd) occurring in ≥10% of patients were neutropenia (53%/37%), pneumonia (18%/11%), anemia (16%/21%), lymphopenia (16%/11%), hypokalemia (12%/10%), leukopenia (11%/6%), and cataract (11%/10%); grade 3/4 infection rates were 40%/29%. The most common serious TEAE was pneumonia (17%/11%). 11% of patients in the D-Rd arm and 22% in the Rd arm discontinued treatment due to an adverse event. The complete updated data set will be presented at the meeting with additional efficacy endpoints, including MRD-negativity rate. Conclusion : After 48 months follow up, the addition of DARA to Rd continues to demonstrate a superior PFS benefit. More patients continued to have deeper and more durable responses with D-Rd vs Rd alone. No new safety concerns were observed with longer follow-up. These results continue to support the use of D-Rd in the first line of treatment for patients with transplant-ineligible NDMM. Disclosures Kumar: Sanofi: Research Funding; Carsgen: Other, Research Funding; Cellectar: Other; Celgene/BMS: Other: Research funding for clinical trials to the institution, Consulting/Advisory Board participation with no personal payments; Genentech/Roche: Other: Research funding for clinical trials to the institution, Consulting/Advisory Board participation with no personal payments; Takeda: Other: Research funding for clinical trials to the institution, Consulting/Advisory Board participation with no personal payments; Janssen Oncology: Other: Research funding for clinical trials to the institution, Consulting/Advisory Board participation with no personal payments; Novartis: Research Funding; Oncopeptides: Consultancy, Other: Independent Review Committee; IRC member; Karyopharm: Consultancy; Merck: Consultancy, Research Funding; Kite Pharma: Consultancy, Research Funding; AbbVie: Other: Research funding for clinical trials to the institution, Consulting/Advisory Board participation with no personal payments; Tenebio: Other, Research Funding; BMS: Consultancy, Research Funding; MedImmune: Research Funding; Genecentrix: Consultancy; Dr. Reddy's Laboratories: Honoraria; Amgen: Consultancy, Other: Research funding for clinical trials to the institution, Consulting/Advisory Board participation with no personal payments, Research Funding; Adaptive Biotechnologies: Consultancy. Facon:Celgene, Janssen, Takeda, Amgen, Roche, Karyopharm, Oncopeptides, BMS, Sanofi: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Usmani:Abbvie: Consultancy; Janssen: Consultancy, Honoraria, Other: Speaking Fees, Research Funding; Takeda: Consultancy, Honoraria, Other: Speaking Fees, Research Funding; Sanofi: Consultancy, Honoraria, Research Funding; Celgene: Other; GSK: Consultancy, Research Funding; Merck: Consultancy, Research Funding; BMS, Celgene: Consultancy, Honoraria, Other: Speaking Fees, Research Funding; Amgen: Consultancy, Honoraria, Other: Speaking Fees, Research Funding; SkylineDX: Consultancy, Research Funding; Seattle Genetics: Consultancy, Research Funding; Pharmacyclics: Research Funding; Incyte: Research Funding; Array Biopharma: Research Funding. Plesner:Janssen: Consultancy. Orlowski:Founder of Asylia Therapeutics, Inc., with associated patents and an equity interest, though this technology does not bear on the current submission.: Current equity holder in private company, Patents & Royalties; STATinMED Research: Consultancy; Laboratory research funding from BioTheryX, and clinical research funding from CARsgen Therapeutics, Celgene, Exelixis, Janssen Biotech, Sanofi-Aventis, Takeda Pharmaceuticals North America, Inc.: Research Funding; Amgen, Inc., AstraZeneca, BMS, Celgene, EcoR1 Capital LLC, Forma Therapeutics, Genzyme, GSK Biologicals, Ionis Pharmaceuticals, Inc., Janssen Biotech, Juno Therapeutics, Kite Pharma, Legend Biotech USA, Molecular Partners, Regeneron Pharmaceuticals, Inc.,: Honoraria, Membership on an entity's Board of Directors or advisory committees; Sanofi-Aventis, Servier, Takeda Pharmaceuticals North America, Inc.: Honoraria, Membership on an entity's Board of Directors or advisory committees. Touzeau:Takeda: Consultancy, Honoraria, Other: Travel, Accommodations, Expenses; Abbvie: Consultancy, Honoraria, Other: Travel, Accommodations, Expenses, Research Funding; Amgen: Consultancy, Honoraria, Other: Travel, Accommodations, Expenses; GlaxoSmithKline: Honoraria, Research Funding; Janssen: Consultancy, Honoraria, Other: Travel, Accommodations, Expenses; Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Sanofi: Honoraria, Research Funding. Bahlis:BMS/Celgene and Janssen: Consultancy, Honoraria, Other: Travel, Accomodations, Research Funding; Genentech: Consultancy, Honoraria; GSK: Consultancy, Honoraria; Sanofi: Consultancy, Honoraria; Takeda: Consultancy, Honoraria; Amgen: Consultancy, Honoraria; Karyopharm Therapeutics: Consultancy, Honoraria; AbbVie: Consultancy, Honoraria. Goldschmidt:Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Grants and/or provision of Investigational Medicinal Product:, Research Funding; Takeda: Membership on an entity's Board of Directors or advisory committees, Research Funding; Johns Hopkins University: Other: Grants and/or provision of Investigational Medicinal Product; Incyte: Research Funding; University Hospital Heidelberg, Internal Medicine V and National Center for Tumor Diseases (NCT), Heidelberg, Germany: Current Employment; GlaxoSmithKline (GSK): Honoraria; Adaptive Biotechnology: Membership on an entity's Board of Directors or advisory committees; Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Grants and/or provision of Investigational Medicinal Product, Research Funding; Mundipharma GmbH: Research Funding; Sanofi: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other, Research Funding; Novartis: Honoraria, Research Funding; Chugai: Honoraria, Other: Grants and/or provision of Investigational Medicinal Product:, Research Funding; Dietmar-Hopp-Foundation: Other: Grants and/or provision of Investigational Medicinal Product:; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Grants and/or provision of Investigational Medicinal Product:, Research Funding; BMS: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Grants and/or provision of Investigational Medicinal Product:, Research Funding; Molecular Partners: Research Funding; Merck Sharp and Dohme (MSD): Research Funding. O'Dwyer:Celgene: Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company); BMS: Research Funding; Carrick Therapeutics: Current equity holder in publicly-traded company, Membership on an entity's Board of Directors or advisory committees; Adaptive Biotechnologies: Consultancy, Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company); Janssen: Consultancy, Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company); AbbVie: Consultancy; ONK Therapeutics: Consultancy, Current Employment, Current equity holder in publicly-traded company, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties, Research Funding. Venner:Celgene, Amgen: Research Funding; Janssen, BMS/Celgene, Sanofi, Takeda, Amgen: Honoraria. Weisel:Adaptive: Consultancy, Honoraria; Bristol-Myers Squibb: Consultancy, Honoraria; Sanofi: Consultancy, Honoraria, Research Funding; Amgen: Consultancy, Honoraria, Research Funding; Roche: Consultancy, Honoraria; Janssen: Consultancy, Honoraria, Research Funding; Celgene: Consultancy, Honoraria, Research Funding; Karyopharm: Consultancy, Honoraria; GlaxoSmithKline: Honoraria; Takeda: Consultancy, Honoraria; Abbvie: Consultancy, Honoraria. Hulin:Celgene/Bristol-Myers Squibb, Janssen, GlaxoSmithKline, and Takeda: Honoraria. Karlin:GlaxoSmithKline: Honoraria, Membership on an entity's Board of Directors or advisory committees; Takeda: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel support, personal fees; Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel support, personal fees; Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel support, personal fees; Celgene: Other: Personal fees; Sanofi: Honoraria; AbbVie: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel support; Celgene/Bristol-Myers Squibb: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel support. Preis:Janssen: Other: for factor XI inhibitor. Broyl:Janssen, Celgene, Takeda, Amgen: Honoraria. Hansson:Amgen, Celgene, Takeda, Janssen Cilag: Consultancy. Krevvata:Janssen: Current Employment. Wang:Janssen: Current Employment. Van Rampelbergh:Janssen: Current Employment. Ukropec:Janssen: Current Employment, Current equity holder in publicly-traded company. Uhlar:Janssen: Current Employment, Current equity holder in publicly-traded company. Kobos:Janssen: Current Employment, Current equity holder in publicly-traded company. Perrot:Amgen, BMS/Celgene, Janssen, Sanofi, Takeda: Consultancy, Honoraria, Research Funding.

CT053 comprises autologous T cells genetically modified with a second-generation chimeric antigen receptor (CAR) incorporating a fully human B-cell maturation antigen (BCMA)-specific single-chain fragment variant (25C2) with high binding affinity. Twenty-four subjects have been treated in phase 1 studies with an 87.5% overall response rate (ORR), 79.2% complete response (CR), and a median duration of response of 21.8 months without inducing immunogenicity [Blood (2019) 134 (Supplement_1): 4435]. Here we present the ongoing phase 1b/2 study (LUMMICAR-2) conducted in North America (NCT03915184) to evaluate safety and clinical efficacy. Eligible subjects with relapsed/refractory multiple myeloma (RRMM) had received ≥3 prior lines of therapy including a proteasome inhibitor (PI), an immunomodulatory drug (IMiD), and an anti-CD38 antibody, and had measurable disease per International Myeloma Working Group (IMWG) criteria. All subjects received a lymphodepletion regimen of cyclophosphamide (500 mg/m2/day ×2 days) and fludarabine (25 mg/m2/ day × 3 days). A single infusion of CT053 at the targeted 1.5-3.0×108 CAR+ T-cell dose was administered after lymphodepletion. Primary objectives for phase 1b were to evaluate the safety and tolerability of CT053 and to identify the recommended phase 2 dose. Adverse events (AEs) were graded using CTCAE, v5.0; cytokine release syndrome (CRS) and neurotoxicity were graded according to ASTCT CRS consensus grading system (Lee DW et al, 2019). The response was assessed per 2016 IMWG criteria, and minimal residual disease (MRD) was assessed by next generation flow cytometry or sequencing. As of July 28, 2020, 20 subjects have enrolled, and 14 subjects have received CT053 infusion in the phase 1b portion of the study, including 8 subjects who received 1.5-1.8×108 CAR+ T cells while 6 subjects received 2.5-3.0×108 CAR+ T cells. The treated subjects had a median age of 59 years (range 42-73), had received a median of 6 (range 3-11) prior lines of treatment, 93% were triple refractory to a PI, IMiD, and anti-CD38 antibody, and 64% were penta-refractory. In addition, 36% of the subjects had extramedullary disease at baseline, and 64% had high-risk cytogenetics. All subjects received bridging therapy. The most common ≥ grade 3 AE was hematological toxicity. All subjects experienced ≥ grade 3 neutropenia (100%) and leukopenia (100%), and 36% of subjects had ≥ grade 3 thrombocytopenia within 30 days of treatment. No grade 3 or higher CRS or neurotoxicity was observed. Twelve of 14 subjects (86%) experienced grade 1 or 2 CRS, including 2 subjects who experienced grade 2 CRS and 1 subject who had grade 2 neurotoxicity. CRS events had a generally predictable time to onset, occurring at a median of 2 days post infusion with a median duration of 4 days (range 1-6). Two subjects received tocilizumab, and one subject with grade 2 CRS received both tocilizumab and steroids. One subject experienced grade 2 neurotoxicity with complete resolution within 24 hours upon administration of dexamethasone. At the data cutoff, 10 subjects were evaluable for at least two months of efficacy assessment with a median follow-up of 4.5 months (range 2-8). A 100% ORR was observed, with 2 stringent complete responses, 2 CRs, 1 very good partial response, and 5 partial responses. Of the 12 subjects with evaluable bone marrow samples, 11 were MRD-negative at the 10-5 sensitivity level. Responses were independent of baseline bone marrow BCMA expression. CT053 transgene levels showed expansion and persistence in peripheral blood, with peak expansion at 7-14 days after infusion. All subjects showed similar kinetics of rapid declines in serum free light chains and soluble BCMA (sBCMA) levels within 1 month, and continued depletion in sBCMA suggests CT053-mediated pharmacodynamic activity. Serum C-reactive protein and cytokine levels (i.e., IL-6, IFNγ, IL-8, IL-10) increased post-infusion within 7 days and correlated with the onset of CRS symptoms. Collectively, these results demonstrate that CT053 at a target dose of 1.5-3.0×108 CAR+ T cells delivers early and deep responses, including MRD negativity, with an acceptable safety profile in subjects with heavily pretreated relapsed or refractory MM. The promising results from the ongoing LUMMICAR-2 study are consistent with the previous phase 1 studies and support the launch of a pivotal Phase 2 LUMMICAR-2 study. Updated results will be presented at the conference. Disclosures Kumar: Carsgen: Other, Research Funding; Kite Pharma: Consultancy, Research Funding; Oncopeptides: Consultancy, Other: Independent Review Committee; IRC member; Celgene/BMS: Other: Research funding for clinical trials to the institution, Consulting/Advisory Board participation with no personal payments; Genentech/Roche: Other: Research funding for clinical trials to the institution, Consulting/Advisory Board participation with no personal payments; Adaptive Biotechnologies: Consultancy; Janssen Oncology: Other: Research funding for clinical trials to the institution, Consulting/Advisory Board participation with no personal payments; Dr. Reddy's Laboratories: Honoraria; Tenebio: Other, Research Funding; Genecentrix: Consultancy; BMS: Consultancy, Research Funding; AbbVie: Other: Research funding for clinical trials to the institution, Consulting/Advisory Board participation with no personal payments; Amgen: Consultancy, Other: Research funding for clinical trials to the institution, Consulting/Advisory Board participation with no personal payments, Research Funding; MedImmune: Research Funding; Cellectar: Other; Merck: Consultancy, Research Funding; Takeda: Other: Research funding for clinical trials to the institution, Consulting/Advisory Board participation with no personal payments; Sanofi: Research Funding; Novartis: Research Funding; Karyopharm: Consultancy. Baz:Sanofi, Karypharm, Janssen, Celgene: Other: Advisory board; Karyopharm, janssen, Bristol Myers Squibb, Celgene, Merck, Sanofi, Abbvie Inc.: Research Funding. Orlowski:Amgen, Inc., AstraZeneca, BMS, Celgene, EcoR1 Capital LLC, Forma Therapeutics, Genzyme, GSK Biologicals, Ionis Pharmaceuticals, Inc., Janssen Biotech, Juno Therapeutics, Kite Pharma, Legend Biotech USA, Molecular Partners, Regeneron Pharmaceuticals, Inc.,: Honoraria, Membership on an entity's Board of Directors or advisory committees; Founder of Asylia Therapeutics, Inc., with associated patents and an equity interest, though this technology does not bear on the current submission.: Current equity holder in private company, Patents & Royalties; STATinMED Research: Consultancy; Sanofi-Aventis, Servier, Takeda Pharmaceuticals North America, Inc.: Honoraria, Membership on an entity's Board of Directors or advisory committees; Laboratory research funding from BioTheryX, and clinical research funding from CARsgen Therapeutics, Celgene, Exelixis, Janssen Biotech, Sanofi-Aventis, Takeda Pharmaceuticals North America, Inc.: Research Funding. Anderson:Amgen: Consultancy, Honoraria, Research Funding; BMS: Consultancy, Honoraria, Research Funding; GSK: Consultancy, Honoraria, Research Funding; Janssen: Consultancy, Honoraria, Research Funding; Karyopharm: Consultancy, Honoraria, Research Funding. Ma:CARsgen Therapeutics Corp.: Current Employment. Bilgi:CARsgen Therapeutics Corp.: Other: Current shareholder in the company. Kansagra:Alnylam Pharmaceuticals, Bristol Myers Squibb /Celgene, GlaxoSmithKline, Janssen, Pharmacyclics, Takeda Pharmaceuticals, Pfizer, Karyopharm Therpeutics: Other: Advisory Board. Kapoor:Janssen: Research Funding; Cellectar: Consultancy; Takeda: Honoraria, Research Funding; GlaxoSmithKline: Research Funding; Celgene: Honoraria; Amgen: Research Funding; Sanofi: Consultancy, Research Funding. Li:CARsgen Therapeutics Co. LtD: Current Employment, Current equity holder in private company. Brayer:Bristol-Myers Squibb, WindMIL Therapeutics: Research Funding; Janssen: Consultancy; Bristol-Myers Squibb, Janssen, Amgen: Speakers Bureau.

Abstract Background: Persons of African ancestry (AA) experience a 1.5-2-fold risk of multiple myeloma (MM) compared to persons of European ancestry (EA). We assembled a set of MM patients with self-reported AA in order to evaluate the contribution of genetics to etiology in this high-risk group. Methods: Here we present the results of a meta-analysis of two GWAS in 1,813 cases and 8,871 controls of AA. We also conducted an admixture mapping scan to identify risk alleles associated with local ancestry, fine-mapped the 23 known susceptibility loci to find markers that could better capture MM risk in individuals of AA, and constructed a polygenic risk score (PRS) to assess the aggregated effect of known MM risk alleles. Finally, we conducted an eQTL analysis measuring gene expression in those genes harboring a risk variant in malignant plasma cells from 292 of the patients from a single site. Results: In GWAS analysis, we identified two suggestive novel loci located at 9p24.3 and 9p13.1 at P&lt;1 × 10-6, but no genome-wide significant association was noted. In admixture mapping, we observed a genome-wide significant inverse association between local AA at 2p24.1-23.1 and MM risk in AA individuals. 20 of the 23 known EA risk variants showed directional consistency and 9 replicated at P&lt;0.05 in AA individuals. In eight regions, we identified markers that better capture MM risk in persons of AA. AA individuals with a PRS in the top 10% had a 1.82-fold (95%CI: 1.56, 2.11) increased MM risk compared to those with average risk (25-75%). The strongest functional association was between the risk allele for variant rs56219066 at 5q15 and lower ELL2 expression (P= 5.1 × 10–12). Conclusion: Our study shows that common genetic variation contributes to MM risk individuals of AA. This abstract is also being presented as Poster C040. Citation Format: Zhaohui Du, Niels Weinhold, Gregory Chi Song, Kristen A. Rand, David J. Van Den Berg, Amie E. Hwang, Xin Sheng, Victor Hom, Sikander Ailawadhi, Ajay K. Nooka, Seema Singhal, Karen Pawlish, Edward Peters, Cathryn Bock, Ann Mohrbacher, Alexander Stram, Sonja I. Berndt, William J. Blot, Graham Casey, Victoria L. Stevens, Rick Kittles, Phyllis J. Goodman, W. Ryan Diver, Anselm Hennis, Barbara Nemesure, Eric A. Klein, Benjamin A. Rybicki, Janet L. Stanford, John S. Witte, Lisa Signorello, Esther M. John, Leslie Bernstein, Antoinette Stroup, Owen W. Stephens, Maurizio Zangari, Frits Van Rhee, Andrew Olshan, Wei Zheng, Jennifer J. Hu, Regina Ziegler, Sarah J. Nyante, Sue Ann Ingles, Michael Press, John David Carpten, Stephen Chanock, Jayesh Mehta, Graham A Colditz, Jeffrey Wolf, Thomas G. Martin, Michael Tomasson, Mark A. Fiala, Howard Terebelo, Nalini Janakiraman, Laurence Kolonel, Kenneth C. Anderson, Loic Le Marchand, Daniel Auclair, Brian C.-H. Chiu, Elad Ziv, Daniel Stram, Ravi Vij, Leon Bernal-Mizrachi, Gareth J. Morgan, Jeffrey A. Zonder, Carol Ann Huff, Sagar Lonial, Robert Z. Orlowski, David V. Conti, Christopher A. Haiman, Wendy Cozen. A meta-analysis of genome-wide association study and eQTL analysis of multiple myeloma among African Americans [abstract]. In: Proceedings of the Twelfth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2019 Sep 20-23; San Francisco, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl_2):Abstract nr PR05.

8537 Background: Carfilzomib (CFZ) is a proteasome inhibitor, active against hematologic malignancies. Preclinically, CFZ overcomes bortezomib (BTZ) resistance in multiple tumors, including myeloma (MM). PX-171–004 is an ongoing Phase II study evaluating safety and efficacy of CFZ in MM patients with relapsed disease after 1–3 prior therapies. Overall Response Rate (ORR) of 35.5% for all subjects was previously reported (ASH 2008); updated data are now available. Methods: Patients were divided into two cohorts: BTZ-naïve and BTZ-exposed. CFZ 20 mg/m2 was administered Days 1, 2, 8, 9, 15 and 16 in a 28-day cycle, for up to 12 cycles. Dexamethasone 4 mg po was administered prior to each dose in Cycle 1. The primary endpoint was ORR, defined as Partial Response (PR) or better. Secondary endpoints included Duration Of Response (DOR) and Time To Progression (TTP). Results: 31 patients were enrolled; 14 (45%) BTZ-naïve and 17 (55%) BTZ-exposed. Of the BTZ-exposed cohort, 2 subjects received BTZ exclusively as a single agent, 6 had BTZ in a chemotherapy combination, and 9 received BTZ in a transplant regime. Overall, 23 (74%) subjects had > 1 prior therapy and 27 (87%) received transplant. In BTZ-naïve patients, CFZ achieved an ORR of 57%; median DOR of 8.6 mos (range >1.9 to >9.7 mos). To date, 7 patients (50%) remain progression free and 3 patients have completed 12 cycles. The median follow-up was 10 mos and the median TTP has not been reached. For the BTZ- exposed group, CFZ achieved an ORR of 18%; median DOR not yet reached (>8.5 mos) (range >1 d to >8.5 mos). 7 patients (41%) are progression free and 3 patients have completed 12 cycles. Median follow-up and TTP were 9.2 and 8.9 mos, respectively. Conclusions: These preliminary results demonstrate that single-agent CFZ is tolerable for at least 1 yr and achieves sustained responses in relapsed MM. Prior BTZ mono/combination therapy does not preclude durable response with CFZ. These data support continuing evaluation of CFZ in the treatment of relapsed MM. [Table: see text] [Table: see text]

LBA3 Background: Bortezomib (btz) combined with lenalidomide (len) and dexamethasone (dex) (VRd) is a standard initial therapy for NDMM. Carfilzomib (cfz), a next-generation proteasome inhibitor, in combination with len-dex (KRd) has shown higher efficacy in phase II trials. This randomized phase III trial was designed to examine if KRd improves progression free survival (PFS) compared to VRd in NDMM (current results), and whether indefinite maintenance with len improves OS compared with two-year maintenance (to be analyzed once data matures). Methods: Patients (Pts) with NDMM, were randomized to receive VRd or KRd in a 1:1 fashion for 36 weeks followed by a second randomization (1:1) to indefinite versus two years of len maintenance. Pts without del17p, t (14;16), t(14;20), plasma cell leukemia or high-risk GEP70 profile, were enrolled. VRd arm included btz 1.3 mg/m2 on days(d) 1, 4, 8, and 11 (d 1, 8 for cycles 9-12), len 25 mg d 1-14, and dex 40 mg d 1, 2, 4, 5, 8, 9, 11, 12 of a 3-week (wk) cycle for 12 cycles, while pts in the KRd arm received cfz 36 mg/m2 d 1, 2, 8, 9, 15, 16 with len 25 mg daily on d 1-21 and dex 40 mg wkly, in 4 wk cycles for 9 cycles. Maintenance included len 15mg d 1-21 every 4 wks. The study was designed to detect a hazard ratio (HR)=0.75 with 80% power at 1-sided 2.5% alpha and 399 PFS events (progression or death regardless of intervening therapy). Results: The study accrued 1087 pts (VRd=542, KRd=545). The median age was 65y. Treatment, efficacy, and toxicity data are in the table. At the second of 3 planned interim analyses, with PFS HR=1.04 (95% CI, 0.8 to 1.3, p=0.74), futility was met. Median PFS was VRd=34.4m and KRd=34.6m; no differences were seen based on age (<65 or ≥65), presence or absence of t(4;14) or ISS stage. The three-year OS (95% CI) was similar: VRd 84% (80 to 88) and KRd 86% (82 to 89). Conclusions: In this randomized phase 3 trial, KRd did not improve PFS compared with VRd in NDMM. A significantly higher rate of cardio-pulmonary and renal toxicity was observed with KRd, while neuropathy rates were higher with VRd. VRd remains the standard triplet induction regimen in standard and intermediate risk NDMM, and a suitable backbone for 4 drug combinations. Clinical trial information: NCT01863550 . [Table: see text]

Purpose: Multiple myeloma (MM) treatment has changed tremendously, with significant improvement in patient out-comes. One group with a suboptimal benefit is patients with high-risk cytogenetics, as tested by conventional karyotyping or fluorescence in situ hybridization (FISH). Methodology for these tests has been published, but not necessarily standardized. Methods: We address variability in the testing and reporting methodology for MM cytogenetics in the United States using the ongoing African American Multiple Myeloma Study (AAMMS). We evaluated clinical and cytogenetic data from 1,221 patients (1,161 with conventional karyotyping and 976 with FISH) tested between 1998 and 2016 across 58 laboratories nationwide. Results: Interlab and intralab variability was noted for the number of cells analyzed for karyotyping, with a significantly higher number of cells analyzed in patients in whom cytogenetics were normal (P 5.0025). For FISH testing, CD138-positive cell enrichment was used in 29.7% of patients and no enrichment in 50% of patients, whereas the remainder had unknown status. A significantly smaller number of cells was analyzed for patients in which CD138 cell enrichment was used compared with those without such enrichment (median, 50 v 200; P, .0001). A median of 7 loci probes (range, 1-16) were used for FISH testing across all laboratories, with variability in the loci probed even within a given laboratory. Chromosome 13–related abnormalities were the most frequently tested abnormality (n5956; 97.9%), and t(14;16) was the least frequently tested abnormality (n 5 119; 12.2%). Conclusions: We report significant variability in cytogenetic testing across the United States for MM, potentially leading to variability in risk stratification, with possible clinical implications and personalized treatment approaches.

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 .