Abstract: 8511 Background: Venetoclax (Ven) is a selective, potent, oral BCL-2 inhibitor that induces apoptosis in multiple myeloma (MM) cells in vitro. It has shown synergistic activity with bortezomib (V) and dexamethasone (d). Combination of the CD38 monoclonal antibody daratumumab (D) with Ven is hypothesized to further increase anti-myeloma activity based on dual mechanisms of pro-apoptotic effects on tumor cells and enhanced immune stimulation. Methods: This ongoing Phase 1/2, nonrandomized, multicenter study (NCT03314181) is evaluating safety, efficacy and pharmacokinetics (PK) of VenDd +/- V in patients (pts) with relapsed/refractory MM. In Part 1, pts with t(11;14) who received ≥1 prior line of therapy (PI and an immunomodulatory drug) were treated with VenDd [Ven QD + D 16 mg/kg IV + d 40 mg weekly]. In Part 2, pts irrespective of t(11;14) status, non-refractory to PIs and who received 1–3 prior lines of therapy were treated with VenDVd [Ven QD + D 16 mg/kg IV + V (1.3 mg/m 2 ) + d (20 mg)]. A randomized, open-label expansion (Part 3) will further evaluate and compare safety and efficacy of VenDd (400 or 800 mg Ven dose levels) with control DVd in pts with t(11;14). Results: As of Dec 05, 2019, 48 pts were enrolled. Part 1 included 24 pts with t(11;14), median age 63 (range 51–76). Part 2 included 24 pts, median age 65 (range 41–80) of which 6 (25%) had t(11;14). Frequent adverse events (AEs; VenDd/VenDVd) were fatigue (71%/25%), diarrhea (58%/46%), nausea (46%/50%), insomnia (33%/50%), upper respiratory tract infection (33%/21%), cough (42%/9%), and dyspnea (25%/25%). Frequent Grade ≥ 3 AEs in pts on VenDd were neutropenia (17%), hypertension (12%), fatigue and hyperglycemia (8% each), and in pts on VenDVd were insomnia (21%), diarrhea and thrombocytopenia (8% each). Nine pts had infection-related Grade ≥ 3 AEs (5 VenDd, 4 VenDVd). Eighteen pts had a serious AE (11 VenDd, 7 VenDVd) with pyrexia (n = 3) being most common. One pt on VenDVd died of progressive disease. PK analyses showed that addition of D and V did not impact Ven exposure. Median follow-up time (VenDd/VenDVd) was 10 and 9 months. Overall response rate in VenDd/VenDVd was 96%/92% and 96%/79% had ≥ very good partial response rate. Median progression free survival and duration of response were not reached. Conclusions: Pts treated with VenDd +/- V continue to demonstrate a tolerable safety profile with encouraging efficacy, notably among pts with t(11;14) treated with VenDd. Safety, efficacy, PK, and cytogenetics analyses will be updated for presentation. Clinical trial information: NCT03314181 .

Abstract: This phase I study evaluated elotuzumab, lenalidomide, and dexamethasone in patients with relapsed or refractory multiple myeloma (MM). Patients and Methods Three cohorts were enrolled and treated with elotuzumab (5.0, 10, or 20 mg/kg intravenously) on days 1, 8, 15, and 22 of a 28-day cycle in the first two cycles, and days 1 and 15 of each subsequent cycle; lenalidomide 25 mg orally [PO] on days 1 to 21; and dexamethasone 40 mg PO weekly. Dose-limiting toxicities (DLTs) were assessed during cycle 1 of each cohort, and clinical responses were evaluated during each cycle. The first five patients received up to six cycles of therapy; subsequent patients were treated until disease progression. Results Twenty-nine patients with advanced MM and a median of three prior MM therapies were enrolled; 28 patients were treated, three each in the 5.0-mg/kg and 10-mg/kg cohorts and 22 in the 20-mg/kg cohort. No DLTs were observed up to the maximum proposed dose of 20 mg/kg. The most frequent grade 3 to 4 toxicities were neutropenia (36%) and thrombocytopenia (21%). Two patients experienced a serious infusion reaction (one grade 4 anaphylactic reaction and one grade 3 stridor) during the first treatment cycle. Objective responses were obtained in 82% (23 of 28) of treated patients. After a median of 16.4 months follow-up, the median time to progression was not reached for patients in the 20-mg/kg cohort who were treated until disease progression. Conclusion The combination of elotuzumab, lenalidomide, and low-dose dexamethasone was generally well tolerated and showed encouraging response rates in patients with relapsed or refractory MM.

Abstract: Introduction: Daratumumab is an anti-CD38 IgGκ monoclonal antibody that has been combined successfully with lenalidomide and dexamethasone. The combination of daratumumab with lenalidomide and dexamethasone (DRd) has been compared with lenalidomide and dexamethasone alone (Rd) in patients (pts) with relapsed or refractory multiple myeloma (RRMM) in a randomized phase 3 study (Dimopoulos MA, et al. N Engl J Med 2016; in press). In a pre-specified interim analysis, the DRd combination demonstrated significantly longer progression-free survival (PFS) in addition to deep and durable responses compared with the Rd arm. We performed subgroup analyses to further examine these efficacy data according to prior treatment exposure. Methods: Pts who received ≥1 prior line of therapy were randomized (1:1) to Rd (lenalidomide: 25 mg PO on Days 1-21 of each 28-day cycle; dexamethasone: 40 mg PO weekly) with or without daratumumab (16 mg/kg IV qw for 8 weeks, q2w for 16 weeks, then q4w until progression). The primary endpoint was PFS. Pts who were refractory to lenalidomide were not eligible. All analyses were performed in pts who received 1 to 3 prior lines of therapy. Results: Median follow-up was 13.5 months. Pts who were lenalidomide-naive prior to the start of study treatment (DRd, n=226; Rd, n=219) demonstrated significantly longer PFS with DRd vs Rd (median: not reached [NR] vs 18.4 months; HR, 0.36; 95% CI, 0.25-0.52; P 〈 0.0001), with estimated 12-month PFS rates of 83.0% vs 59.9%, respectively. ORR was significantly higher with DRd vs Rd (96% vs 79%), with ≥VGPR rates of 76% vs 47% and ≥CR rates of 44% vs 21%, respectively (P 〈 0.0001 for all). In the lenalidomide-exposed subgroup (DRd, n=46; Rd, n=45), median PFS was NR in both treatment groups (HR, 0.49; 95% CI, 0.22-1.12; P=0.0826); estimated 12-month PFS rates were 84.1% vs 63.1%, respectively. ORR was higher with DRd vs Rd but did not reach statistical significance (87% vs 71%; P=0.0729); however, rates of ≥VGPR (78% vs 38%; P=0.0001) and ≥CR (44% vs 12%; P=0.0011) were significantly improved with DRd vs Rd, respectively. For bortezomib-naive pts (DRd, n=44; Rd, n=45), PFS was significantly longer with DRd vs Rd (median: NR vs 15.8 months; HR, 0.34; 95% CI, 0.13-0.86; P=0.0170), with estimated 12-month PFS rates of 85.4% vs 69.2%, respectively. ORR was significantly higher with DRd vs Rd (98% vs 82%; P=0.0158), with trends toward increased rates of ≥VGPR (74% vs 55%; P=0.0544) and ≥CR (42% vs 23%; P=0.0576). In the bortezomib-exposed pts (DRd, n=228; Rd, n=219), median PFS was NR in DRd vs 18.4 months in Rd (HR, 0.35; 95% CI, 0.24-0.50 P 〈 0.0001); estimated 12-month PFS rates were 82.8% vs 58.7%, respectively. Significant differences in ORR (93% vs 77%), rate of ≥VGPR (77% vs 43%) and rate of ≥CR (44% vs 19%) were observed with DRd vs Rd, respectively (P 〈 0.0001 for all). Among bortezomib-refractory patients (DRd, n=54; Rd, n=49), the PFS benefit of DRd compared with Rd was maintained (median: NR vs 10.3 mo, respectively; HR, 0.46; 95% CI, 0.25-0.85; P=0.0117; Figure). The estimated 12-month PFS rates were 70.8% vs 44.4%, respectively. Similar to bortezomib-exposed pts, ORR (92% vs 68%; P=0.0024), rate of ≥VGPR (75% vs 36%; P=0.0001), and rate of ≥CR (46% vs 13%; P=0.0003) were all significantly higher with DRd vs Rd for bortezomib-refractory pts. Updated data will be presented at the meeting. Conclusions: Among pts who received 1 to 3 prior lines of therapy, significantly longer PFS and higher ORR were observed with DRd vs Rd among pts who previously received bortezomib or were refractory to bortezomib or were lenalidomide-naive. Higher rates of deeper responses were observed in pts who previously received lenalidomide or bortezomib. Follow-up is ongoing to assess PFS in pts who received 1 to 3 prior lines of therapy and previously received lenalidomide. These results further strengthen the significant benefit of combining daratumumab with Rd for RRMM. Figure Progression-free Survival in Bortezomib-refractory Patients who Received 1 to 3 Prior Lines of Therapy Figure. Progression-free Survival in Bortezomib-refractory Patients who Received 1 to 3 Prior Lines of Therapy Disclosures Moreau: Janssen: Honoraria, Speakers Bureau; Novartis: Honoraria; Takeda: Honoraria; Celgene: Honoraria; Amgen: Honoraria; Bristol-Myers Squibb: Honoraria. Kaufman:Pharmacyclics: Consultancy; Incyte: Consultancy; Novartis: Consultancy, Research Funding; Celgene: Consultancy, Research Funding. Sutherland:Celgene: Consultancy, Honoraria; Amgen: Consultancy, Honoraria; Janssen: Consultancy, Honoraria. Lalancette:Celgene: Honoraria; BMS: Honoraria. Iida:Celgene: Honoraria, Research Funding; Janssen Pharmaceuticals: Honoraria, Research Funding. Prince:Janssen: Honoraria; Celgene: Honoraria. Cochrane:BMS: Other: Received sponsorship to attend international meetings; Novartis: Other: Received sponsorship to attend international meetings; Celgene: Other: Received sponsorship to attend international meetings; Takeda: Other: Received sponsorship to attend international meetings. Khokhar:Janssen: Employment. Guckert:Johnson & Johnson: Equity Ownership; Janssen: Employment. Qin:Janssen: Employment. Oriol:Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees; Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees.

Abstract: Introduction: Daratumumab, a human IgGκ monoclonal antibody targeting CD38 with a direct on-tumor and immunomodulatory mechanism of action, is approved in combination with standard-of-care regimens for the treatment of newly diagnosed multiple myeloma (NDMM) and RRMM. When combined with standard of care regimens across four phase 3 studies, daratumumab demonstrated ≥44% reductions in the risk of progression or death, nearly doubled complete response (CR) or better rates, and tripled minimal residual disease (MRD)-negative rates at the 10-5 sensitivity threshold in pts with RRMM or NDMM (Palumbo A, et al. N Engl J Med 2016. 375[8]:754-766; Dimopoulos MA, et al. N Engl J Med 2016. 375[14] :1319-1331; Mateos MV, et al. N Engl J Med 2018. 378[6]:518-528; Facon T, et al. N Engl J Med 2019. 380[22] 2104-2015). In the phase 3 POLLUX study (median follow-up 44.3 months), D-Rd reduced the risk of disease progression or death by 56% and significantly increased the overall response rate (ORR) versus Rd alone (93% vs 76%; P 〈 0.0001) in patients (pts) with RRMM. Here, we present updated efficacy and safety analyses of POLLUX after 〉 4 years of median follow-up. Methods: Pts who received ≥1 prior line of therapy were randomized (1:1) to Rd (lenalidomide 25 mg PO on Days 1-21 of each 28-day cycle; dexamethasone 40 mg per week) ± daratumumab (16 mg/kg IV QW for Cycles 1-2, Q2W for Cycles 3-6, then Q4W until disease progression). Cytogenetic risk was determined by local fluorescence in situ hybridization or karyotyping; pts with high cytogenetic risk had t(4;14), t(14;16), and del17p abnormalities. PFS on subsequent line of therapy (PFS2), an exploratory endpoint, was defined as time from randomization to progression after next line of subsequent therapy or death. Results: A total of 569 pts were randomized (D-Rd, n = 286; Rd, n = 283). At a median follow-up of 51.3 months, D-Rd significantly prolonged progression-free survival (PFS) versus Rd (median 45.8 vs 17.5 months; hazard ratio [HR], 0.43; 95% confidence interval [CI] , 0.35-0.54; P 〈 0.0001; Figure). D-Rd also prolonged PFS versus Rd among pts with 1 prior line of therapy, among pts with 1-3 prior lines of therapy, and regardless of cytogenetic risk status (Table). A PFS benefit with D-Rd was also observed among pts who received prior lenalidomide (median 38.8 vs 18.6 months; HR, 0.34; 95% CI, 0.19-0.59; P 〈 0.0001) and among pts refractory to bortezomib (median 34.3 vs 11.3 months; HR, 0.41; 95% CI, 0.25-0.68; P = 0.0004). D-Rd was associated with a significantly higher ORR versus Rd (93% vs 76%), including higher rates of ≥very good partial response (81% vs 49%) and ≥CR (57% vs 24%; all P 〈 0.0001). Median time to next therapy for D-Rd versus Rd was not reached in the D-Rd group versus 22.8 months in the Rd group (HR, 0.39; 95% CI, 0.30-0.49; P 〈 0.0001). D-Rd significantly prolonged PFS2 versus Rd (median 53.3 vs 31.6 months; HR, 0.54; 95% CI, 0.43-0.68; P 〈 0.0001). In the D-Rd group, 121 deaths were observed versus 133 deaths in the Rd group; follow-up for overall survival is ongoing. The median duration of treatment was 34.3 months in the D-Rd arm versus 16.0 months in the Rd arm. The most common (≥10%) grade 3/4 treatment-emergent adverse events (TEAEs) observed with D-Rd versus Rd included neutropenia (56% vs 42%), anemia (18% vs 22%), thrombocytopenia (15% vs 16%), pneumonia (16% vs 10%), and diarrhea (10% vs 4%). Similar rates of discontinuations due to TEAEs were observed for D-Rd versus Rd (16% vs 15%). The incidence of invasive second primary malignancies was 4.9% and 5.7% for the D-Rd and Rd groups, respectively. Additional efficacy data, including minimal residual disease, and safety analyses will be presented at the meeting. Conclusion: After 〉 4 years of median follow-up, D-Rd continues to demonstrate a significant PFS benefit and higher rates of deeper responses versus Rd alone in pts with RRMM. Although significant PFS benefit was observed with D-Rd in RRMM pts regardless of prior lines of therapy or cytogenetic risk status, the greatest benefit was observed when used in patients treated earlier with D-Rd. The significant improvement in PFS2 suggests a potential survival benefit, but OS data is still immature. No new safety concerns were identified with this additional follow-up. Disclosures Kaufman: Celgene: Consultancy; Winship Cancer Institute of Emory University: Employment; Takeda: Consultancy; Pharmacyclics: Membership on an entity's Board of Directors or advisory committees; Janssen: Honoraria; AbbVie: Consultancy; Bristol-Myers Squibb: Consultancy; Incyte: Consultancy; Karyopharm: Membership on an entity's Board of Directors or advisory committees; TG Therapeutics: Consultancy; Amgen: Consultancy. Usmani:Amgen, Bristol-Myers Squibb, Celgene, Janssen, Merck, SkylineDX, Takeda: Other: Consultant/Advisor; Amgen, Celgene, Janssen, Sanofi, Takeda: Speakers Bureau; Amgen Array Biopharma, Bristol-Myers Squibb, Celgene, Janssen, Merck, Pharmacyclics, Sanofi, Takeda: Other: Research Grant. San-Miguel:Amgen, Bristol-Myers Squibb, Celgene, Janssen, MSD, Novartis, Roche, Sanofi, and Takeda: Consultancy, Honoraria. Bahlis:Celgene: Consultancy, Honoraria; Amgen: Consultancy, Honoraria; Takeda: Consultancy, Honoraria; AbbVie: Consultancy, Honoraria; Janssen: Consultancy, Honoraria. White:Janssen: Consultancy, Honoraria; Amgen: Consultancy, Honoraria; Celgene: Consultancy, Honoraria; Takeda: Consultancy, Honoraria; Sanofi: Consultancy, Honoraria. Cook:Amgen, Bristol-Myers Squib, GlycoMimetics, Seattle Genetics, Sanofi: Honoraria; Janssen, Takeda, Sanofi, Karyopharm, Celgene: Consultancy, Honoraria, Speakers Bureau; Celgene, Janssen-Cilag, Takeda: Honoraria, Research Funding. Ho:Novartis: Other: Trial Investigator meeting travel costs; La Jolla: Other: Trial Investigator meeting travel costs; Janssen: Other: Trial Investigator meeting travel costs; Celgene: Other: Trial Investigator meeting travel costs. Moreau:Takeda: Consultancy, Honoraria; AbbVie: Consultancy, Honoraria; Celgene: Consultancy, Honoraria; Janssen: Consultancy, Honoraria; Amgen: Consultancy, Honoraria. Krevvata:Janssen: Employment. Pei:Janssen: Employment, Equity Ownership. Ukropec:Janssen: Employment, Equity Ownership. Renaud:Janssen: Employment, Equity Ownership. Trivedi:Janssen: Employment, Equity Ownership. Kobos:Janssen: Employment. Dimopoulos:Sanofi Oncology: Research Funding.

Abstract: Abstract 432 Elotuzumab is a humanized monoclonal IgG1 antibody directed against CS1, a cell surface glycoprotein, which is highly and uniformly expressed in multiple myeloma (MM). Elotuzumab induces significant antibody-dependant cytotoxicity (ADCC) against primary myeloma cells in the presence of either autologous or allogeneic peripheral lymphocytes (PBMC), which is significantly enhanced when PBMC effector cells were pretreated with lenalidomide (Tai et al., Blood 112:1329, 2008). The primary objective of the phase 1 portion of the study is to evaluate the maximum tolerated dose (MTD) of elotuzumab in combination with lenalidomide and low dose dexamethasone in patients with relapsed MM. The study is also evaluating safety, pharmacokinetics (PK) and clinical response. Lenalidomide (25 mg PO) is given on Days 1-21 of a 28-day cycle. Elotuzumab in three escalating dose cohorts (5, 10 and 20 mg/kg) is administered by IV infusion on Days 1, 8, 15 and 22 of the 28-day cycle in the first two cycles and then on Days 1 and 15 of each subsequent cycle. Dexamethasone is given weekly at 40 mg PO. Initially, patients received 6 cycles of treatment unless withdrawn earlier due to disease progression or unacceptable. toxicity. The protocol was amended to allow for patients in the 10 and 20 mg/kg cohorts to receive treatment for up to 12 months following enrollment of the last patient. Key entry criteria: age ≥ 18 years; MM with at least one relapse; measurable disease M-protein component in serum and/or in urine; and prior lenalidomide treatment, if any, more than 6 weeks of first dose. To date, 24 patients with a median age of 60 years have been enrolled in the study and 23 patients have received study drug. The median time from initial diagnosis of MM was 5 years and patients had received a median of 3 prior MM treatments. Patients had been previously treated with thalidomide (58%), bortezomib (67%) or lenalidomide (21%) and 42% were refractory to their most recent MM therapy. Patients have been treated in the 3 cohorts; 3 patients each in the first two cohorts (5 and 10 mg/kg elotuzumab) and 17 patients (7 in dose-escalation phase and 10 in the expansion phase) in the third cohort (20 mg/kg). No dose limiting toxicities were identified during the dose-escalation phase of the study and no MTD was established. One patient discontinued in the first cycle due to grade 4 allergic reaction resulting from elotuzumab infusion in the expansion phase of the study. Additional SAEs (1 of each) included grade 2 atrial fibrillation (related to lenalidomide/dexamethasone) and unrelated grade 4 ruptured diverticulum, grade 3 neutropenic fever and grade 3 diarrhea.. Other common grade 3 or 4 AEs included neutropenia (25%) and thrombocytopenia (25%), which were managed by dose withholding or dose reduction of lenalidomide. Approximately 25% of patients experienced grade 1 or 2 chills and/or pyrexia associated with elotuzumab infusion. The best clinical response (IMWG criteria) in the 13 patients who have received at least two cycles of treatment is shown in the table below. Preliminary PK analysis of elotuzumab suggests a serum half-life of 10-11 days at 10 and 20 mg/kg. Elotuzumab at all three doses resulted in near complete saturation of CS1 sites on plasma cells and NK cells in bone marrow and NK cells in the peripheral compartment. In conclusion, the combination of elotuzumab with lenalidomide and low-dose dexamethasone has a manageable adverse event profile and compared to historical data for lenalidomide and high-dose dexamethasone, the preliminary efficacy data (≥ PR of 92%) are very encouraging. Additional safety, efficacy and PK/PD data will be presented at the meeting. Disclosures: Lonial: Celgene: Consultancy; Millennium: Consultancy, Research Funding; BMS: Consultancy; Novartis: Consultancy; Gloucester: Research Funding. Off Label Use: Lenalidomide/dexamethasone in combination with elotuzumab in patients with relapsed/refractory multiple myeloma. Vij:Celgene: Research Funding, Speakers Bureau. Harousseau:Celgene France: Advisory Board; Janssen Cilag France: Advisory Board; Celgene: Honoraria; Janssen Cilag: Honoraria; Novartis: Honoraria; Amgen: Honoraria. Facon:Celgene: Membership on an entity's Board of Directors or advisory committees; Janssen Cilag: Membership on an entity's Board of Directors or advisory committees; BMS: Membership on an entity's Board of Directors or advisory committees. Kaufman:Celgene: Consultancy, Research Funding; Millennium: Consultancy; Genzyme: Consultancy; Merck: Research Funding. Mazumder:Celgene: Speakers Bureau; Millennium: Speakers Bureau. Leleu:Celgene: Research Funding, Speakers Bureau. Fry:Facet Biotech: Employment. Singhal:Facet Biotech: Employment. Jagannath:Millennium: Advisory Board; Merck: Advisory Board.

Abstract: Venetoclax (Ven) is a selective small‐molecule inhibitor of BCL‐2 that exhibits antitumoral activity against MM cells with t(11;14) translocation. We evaluated the safety and efficacy of Ven and dexamethasone (VenDex) combination in patients with t(11;14) positive relapsed/refractory (R/R) multiple myeloma (MM). This open‐label, multicenter study had two distinct phases (phase one [P1], phase two [P2] ). Patients in both phases received VenDex (oral Ven 800 mg/day + oral Dex 40 mg [20 mg for patients ≥75 years] on days 1, 8, and 15, per 21–day cycle). The primary objective of the P1 VenDex cohort was to assess safety and pharmacokinetics. Phase two further evaluated efficacy with objective response rate (ORR) and very good partial response or better. Correlative studies explored baseline BCL2 (BCL‐2) and BCL2L1 (BCL‐X L ) gene expression, cytogenetics, and recurrent somatic mutations in MM. Twenty and 31 patients in P1 and P2 with t(11;14) positive translocation received VenDex. P1/P2 patients had received a median of 3/5 lines of prior therapy, and 20%/87% were refractory to daratumumab. Predominant grade 3/4 hematological adverse events (AEs) with ≥10% occurrence included lymphopenia (20%/19%), neutropenia (15%/7%), thrombocytopenia (10%/10%), and anemia (5%/16%). At a median follow‐up of 12.3/9.2 months, ORR was 60%/48%. The duration of response estimate at 12 months was 50%/61%, and the median time to progression was 12.4/10.8 months. In biomarker evaluable patients, response to VenDex was independent of concurrent del(17p) or gain(1q) and mutations in key oncogenic signaling pathways, including MAPK and NF‐kB. VenDex demonstrated efficacy and manageable safety in heavily‐pre‐treated patients with t(11;14) R/R MM.

Abstract: In POLLUX, daratumumab (D) plus lenalidomide/dexamethasone (Rd) reduced the risk of disease progression or death by 63% and increased the overall response rate (ORR) versus Rd in relapsed/refractory multiple myeloma (RRMM). Updated efficacy and safety after 〉 3 years of follow-up are presented. Patients ( N  = 569) with ≥1 prior line received Rd (lenalidomide, 25 mg, on Days 1–21 of each 28-day cycle; dexamethasone, 40 mg, weekly) ± daratumumab at the approved dosing schedule. Minimal residual disease (MRD) was assessed by next-generation sequencing. After 44.3 months median follow-up, D-Rd prolonged progression-free survival (PFS) in the intent-to-treat population (median 44.5 vs 17.5 months; HR, 0.44; 95% CI, 0.35–0.55; P   〈  0.0001) and in patient subgroups. D-Rd demonstrated higher ORR (92.9 vs 76.4%; P   〈  0.0001) and deeper responses, including complete response or better (56.6 vs 23.2%; P   〈  0.0001) and MRD negativity (10 –5 ; 30.4 vs 5.3%; P   〈  0.0001). Median time to next therapy was prolonged with D-Rd (50.6 vs 23.1 months; HR, 0.39; 95% CI, 0.31–0.50; P   〈  0.0001). Median PFS on subsequent line of therapy (PFS2) was not reached with D-Rd versus 31.7 months with Rd (HR, 0.53; 95% CI, 0.42–0.68; P   〈  0.0001). No new safety concerns were reported. These data support using D-Rd in patients with RRMM after first relapse.