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PURPOSE Venetoclax, an oral BCL-2 inhibitor, has efficacy in t(11;14)-positive relapsed/refractory multiple myeloma (RRMM), which is enhanced by dexamethasone, which promotes BCL-2 dependency. METHODS The randomized, open-label, phase III CANOVA study (ClinicalTrials.gov identifier: NCT03539744 ) enrolled adults with t(11;14)-positive RRMM who had received ≥2 previous lines of therapy. Patients were randomly assigned (1:1) to venetoclax-dexamethasone or pomalidomide-dexamethasone until progression or intolerable toxicity. The primary end point was independent review committee assessed–progression-free survival (PFS) in the intention-to-treat population analyzed by stratified log-rank test (two-sided type I error rate, α = .05), with hazard ratio (HR) and 95% CI estimated by stratified Cox proportional hazard model. Secondary end points included response rates, overall survival (OS), minimal residual disease (MRD) negativity rate (<10 –5 ), and safety. RESULTS Overall, 263 patients were randomly assigned (venetoclax-dexamethasone, n = 133; pomalidomide-dexamethasone, n = 130). Median PFS was 9.9 months (95% CI, 6.9 to 12.6) with venetoclax-dexamethasone versus 5.8 months (95% CI, 3.8 to 9.2) with pomalidomide-dexamethasone (HR, 0.823 [95% CI, 0.596 to 1.136]; P = .24). Overall response and very good partial response or better rates were 62% and 39%, respectively, with venetoclax-dexamethasone versus 35% and 14% with pomalidomide-dexamethasone. MRD negativity rate was 8% with venetoclax-dexamethasone and 0% with pomalidomide-dexamethasone. Median OS was 32.4 months (95% CI, 26.4 to 40.7) with venetoclax-dexamethasone and 26.9 months (95% CI, 20.4 to 38.9) with pomalidomide-dexamethasone (HR, 0.856 [95% CI, 0.612 to 1.197]). Grade ≥3 treatment-emergent adverse event rates were 67% with venetoclax-dexamethasone versus 83% with pomalidomide-dexamethasone. There were 16 (12%) treatment-emergent deaths with venetoclax-dexamethasone versus 8 (6%) with pomalidomide-dexamethasone. CONCLUSION The primary end point of PFS was not met. PFS and OS were numerically longer with venetoclax-dexamethasone versus pomalidomide-dexamethasone in t(11;14)-positive RRMM. Consistent with previous studies, infections were associated with venetoclax-dexamethasone; no new safety signals were observed.

Abstract Introduction : Current standard of care for smoldering multiple myeloma (SMM), an asymptomatic precursor of multiple myeloma (MM), is observation until progression to active MM. Increasing evidence suggests that patients (pts) with SMM at high risk for progression to active MM may benefit from early treatment (tx). In AQUILA, a phase 3 study in pts with high-risk SMM (NCT03301220), daratumumab (Dara) monotherapy significantly reduced risk of progression to active MM or death with a trend of extending overall survival (OS) vs active monitoring (ActMon), with no new safety concerns. Given the evolution in SMM risk stratification, a post hoc analysis was performed to assess outcomes using the IMWG 2020 and IMWG 2020 plus cytogenetic risk models to assess which AQUILA pts benefited most from Dara monotherapy. Safety and efficacy analysis by age and stem cell collection outcomes were also assessed. Methods: Eligible pts with a confirmed diagnosis (≤5 y) of high-risk SMM per IMWG 2014 criteria, defined as clonal bone marrow plasma cells (BMPC) ≥10% and ≥1 risk factor (IgA SMM, serum protein ≥30 g/dL, serum involved:uninvolved free light chain [I/U FLC] ratio ≥8 and &lt;100, immunoparesis with reduction of 2 uninvolved Ig isotypes, and/or clonal BMPC &gt;50% to &lt;60%) at study entry, were randomized 1:1 to receive subcutaneous Dara or ActMon for 39 cycles, 36 months, or until confirmed disease progression (PD), whichever came first. Primary endpoint was progression-free survival (PFS) assessed by independent review committee, defined as progression to active MM (based on IMWG SLiM-CRAB diagnostic criteria) or death. Secondary endpoints included time to first-line (1L) MM tx and OS. For this post hoc analysis, we assessed outcomes by age, IMWG 2020 high-risk SMM criteria (BMPC &gt;20%, monoclonal spike &gt;2 g/dL, serum FLC ratio &gt;20; ≥2 factors=high risk; also known as the Mayo 2018 or the 20-2-20 criteria), and the IMWG 2020 plus cytogenetic criteria (IMWG 2020 criteria + presence of ≥1 high-risk cytogenetic abnormalities [t(4;14), t(14;16), +1q and/or del13q]; ≥3 factors=high risk). Results : Dara tx showed a PFS benefit across all IMWG 2020 risk subgroups (low: hazard ratio [HR], 0.59; intermediate: HR, 0.70), with the largest benefit in the high-risk subgroup, where the PD/death rate in the ActMon arm was ~1.6-fold that in the Dara arm (62.8% vs 37.5%; HR, 0.36). This benefit of Dara vs ActMon was preserved over time, with 5-year PFS rates of 78.2% vs 71.6%, 56.2% vs 42.9%, and 60.4% vs 23.6% in IMWG 2020 low-, intermediate-, and high-risk groups, respectively. There was a positive trend favoring Dara for time to 1L MM treatment across all IMWG 2020 risk groups (low-risk HR, 0.63; 95% CI, 0.22–1.80; intermediate-risk HR, 0.57; 95% CI, 0.35–0.92; high-risk HR, 0.39; 95% CI, 0.25–0.62). IMWG 2020 plus cytogenetic risk classification results will be available at the time of presentation. When comparing the younger (&lt;65y HR, 0.51; 95% CI, 0.32–0.79) vs the older (≥65y, HR, 0.50; 95% CI, 0.32–0.77) pt population, a PFS benefit was observed regardless of age. Similarity was also observed in TEAE incidence rate when looking into &lt;65, 65 to &lt;75, and ≥75 y subgroups (82.7%, 81.1%, and 87.5% with ActMon; 96.2%, 98.5%, and 95.2% with Dara); however, serious TEAEs were more frequently observed in older ActMon pts (12.2%, 18.9%, and 50.0% with ActMon; 24.8%, 35.8%, and 28.6% with Dara). Across all pts treated/monitored in AQUILA, 23 (11.9%) and 41 (20.9%) pts in the Dara and ActMon arms, respectively, received autologous stem cell transplant as part of their first tx after progressing to active MM, with very limited plerixafor use (Dara, 3 [1.6%] vs ActMon, 9 [4.6%]). Median (range) CD34+ cell yield was 5.0 (2–20)×106 cells/kg body weight among 22 pts in the Dara arm and 5.1 (2–21)×106 cells/kg body weight among 39 pts in the ActMon arm. Conclusions : In this analysis, pts with high-risk SMM from the phase 3 AQUILA study treated with Dara monotherapy experienced long-term PFS benefit across IMWG 2020 subgroups, with the most pronounced benefit in the high-risk subgroup. No notable differences in PFS or safety were observed across age subgroups. Early Dara tx for high-risk SMM did not have a detrimental impact on stem cell yield. Although mature OS analyses are forthcoming, overall, these results further support early intervention with Dara monotherapy vs ActMon among pts with high-risk SMM, regardless of risk stratification criteria used.

ABSTRACT Acute renal failure due to cast nephropathy (CAN) is a severe complication of multiple myeloma (MM). Here, we aimed to identify parameters associated with renal outcomes and survival in newly diagnosed MM patients with CAN‐related acute renal failure and to validate the IMWG criteria for renal response. CAN diagnosis was based on biopsy or clinical assessment. Of 787 registered patients, 354 met the inclusion criteria, requiring at least two therapy cycles with documented chemotherapy response, renal response, and eGFR. Baseline free light chain (FLC) levels (median 6825.65 mg/L) decreased below 500 mg/L in 67.8% of patients. According to IMWG classification, renal complete response, partial response, and minimal response were achieved in 33.9%, 19.5%, and 28.0% of patients, respectively. The best eGFR values > 60 mL/min/1.73 m 2 were observed in 33.9% of patients, while 33.3%, 22.3%, and 10.5% had best eGFR values of 30–59, 15–29, and < 15 mL/min/1.73 m 2 , respectively. Renal response correlated with baseline FLC levels, IgG kappa, eGFR, and ECOG status in multivariate analysis, as well as with myeloma response and FLC reduction in univariate analysis. Median overall survival was 77.6 months. Survival correlated with age, myeloma response, ECOG status, FLC kappa type, baseline eGFR, standard‐risk cytogenetics, and calcium levels, among other factors. A comparison of IMWG renal response criteria with classification based solely on best eGFR showed similar utility. Of 136 patients requiring dialysis, 80 (58.8%) were able to discontinue dialysis during therapy. Bortezomib containing myeloma therapy, along with significant FLC reduction, was associated with favorable outcome.

Introduction: Acute kidney injury (AKI) due to cast nephropathy is a medical emergency that leads to a diagnosis of myeloma in less than 3% of cases, but up to 30% of patients develop kidney impairment during the course of their disease. Currently, studies aiming to identify parameters that correlate with kidney function recovery and response to myeloma are limited due to small sample size or single center reports. We have therefore initiated an international collaboration and collected a large number patients (pts) from 16 participating centers. Objectives: To assess the impact of pts and disease characteristics and treatment-specific factors on renal outcome and overall survival and to validate the IMWG criteria for renal response in pts with cast nephropathy and newly diagnosed MM. Patients and Methods: Three-hundred forty-three pts (median age: 65.5 range 35-93 yrs) with newly diagnosed MM and an eGFR &lt;40ml/min/1.73m2 have been selected from 704 pts that had been enrolled in the database hosted by RedCap. Eligibility criteria were a diagnosis of AKI due to cast nephropathy diagnosed either by kidney biopsy (n=119) or on clinical criteria (AKI in the setting of involved free light chain concentration of ≥500 mg/L), newly diagnosed multiple myeloma, &gt;2 cycles of therapy, time and type of therapy, best eGFR and best myeloma response available. Results: Median follow up was 36.9 months. Myeloma therapy resulted in renal CR, and PR as defined by the IMWG criteria in 131 (38.2%) and 57 (16.6%) pts, respectively, 54 (15.7%) and 82 (23.9%) pts had minor response or no response, respectively. Nineteen (5.5%) pts were not classifiable by the IMWG response criteria (pts with eGFR 15-&lt;30, with increase to eGFR to ≥30-&lt;40). An eGFR of &gt;60, ≥30-&lt;60, ≥15-&lt;30, and &lt;15ml/min was achieved by 131 (38.2%), 112 (32.7%), 67 (19.5%), and 33 (9.6%) pts respectively. Myeloma response (≥VGPR) correlated significantly with renal response (≥PRrenal) (OR 1.64, CI 1.05-2.56, p=0.03) and with OS compared to no myeloma response (median 89.7 vs. 39.7 months, HR 2.12, CI 1.55-2.89, p&lt;0.0001). A &gt;50% reduction in FLCs from baseline to treatment cycle 2 (OR 5.92, CI 2.15-19.23, p=0.001) and cycle 3 (OR 5.25, CI 2.15-19.25, p=0.006) were strongly associated with renal response Median OS was 69.6 months (CI 55.4-89.7). Forty-three pts died within the first 12 months of treatment and additional 146 during further FU. Pts with a best GFR of &gt;15ml/min had a significantly longer OS compared to those with GFR &lt;15ml/min (median: 77.9 vs 31.9 months, HR 1.85, CI 1.16-2.94, p=0.01). The comparison of survival of pts with different renal response groups and with the best eGFR showed no statistically significant difference (log rank p=0.1, long rank p=0.057, respectively). Other factors that correlated with longer OS were bortezomib-based therapy (77.9 vs. 44.0 months, HR 1.59, CI 1.05-2.38, p=0.03), M-protein isotype with κ as compared to l light chain type (84.9 vs. 51.4 months, HR 1.47, CI 1.09-2.00, p=0.013), and higher hemoglobin (HR 1.16, CI 1.06-1.26, p=0.001). In contrast, hypercalcemia which was noted in 101 (29.4%) pts (HR 1.10, CI 1.03-1.18, p=0.005), ISS stage III vs. I-II (57.8 vs. 126.2 months, HR 2.26, CI 1.22-4.17, p=0.009), and ECOG status 3+4 vs. 2 vs. 0+1 (24.4 vs. 44.6 vs. 103 months, HR 2.83, CI 2.15-3.74, p&lt;0.0001) were associated with shorter OS. Hypercalcemia, correlated with renal response (OR 1.27, CI 1.12-1.44, p=0.0002), and best eGFR ≥46.4 ml/min (median dichotomized) (OR 1.28, CI 1.14-1.46, p&lt;0.0001). 119 (34.7%) pts required initial dialysis, OS was significantly longer in those who achieved best eGFR levels of &gt;15ml/min. (77.6 vs 31.9 months, HR 0.54, CI 0.34-0.86, p=0.01); 64 (53%) pts discontinued dialysis. Conclusion: Myeloma response correlated with renal response as defined by IMWG criteria. A &gt;50% reduction in FLCs from baseline to treatment cycle ≥2 was strongly associated with renal response. OS was longer in pts with renal response, in pts receiving bortezomib-based therapy, and in pts with kappa light chain M-proteins. Hypercalcemia was frequent (29.4%), and associated with higher renal response rate and best eGFR, but shorter OS. Pts on dialysis who achieved eGFR &gt;15ml/min had better survival. Fast diagnostic work up, rapid treatment initiation and achieving significant myeloma response (≥VGPR) is essential to prevent irreversible kidney damage. Including novel immunotherapies may further improve outcome.

Introduction: High-risk smoldering multiple myeloma (SMM) is an asymptomatic precursor disorder to active multiple myeloma (MM) without approved treatment options. However, recent evidence suggests patients at high risk of progression to MM may benefit from early treatment. Daratumumab (DARA) is a human IgGκ monoclonal antibody targeting CD38 with direct on-tumor and immunomodulatory mechanisms of action. DARA is approved as monotherapy for relapsed/refractory MM (RRMM) and in combination with standard-of-care regimens for RRMM and newly diagnosed MM. Based on the encouraging activity and tolerability observed with DARA monotherapy in patients with intermediate- or high-risk SMM in the phase 2 CENTAURUS study, the phase 3 AQUILA study sought to determine if DARA could delay progression to MM versus active monitoring. Here we report the primary analysis from the AQUILA study. Methods: Eligible patients had a confirmed diagnosis of high-risk SMM for ≤5 years, defined as clonal bone marrow plasma cells (BMPCs) ≥10% and ≥1 risk factor (serum M protein ≥30 g/L, IgA SMM, immunoparesis with reduction of 2 uninvolved Ig isotypes, serum involved:uninvolved free light chain ratio ≥8 and &lt;100, and/or clonal BMPCs &gt;50% to &lt;60%). Focal and lytic lesion assessment was performed in screening by CT and MRI and centrally reviewed prior to study enrollment. Patients were randomized 1:1 to receive DARA SC versus active monitoring. DARA (QW in Cycles 1 and 2, Q2W in Cycles 3-6, and Q4W thereafter) was given in 28-day cycles until cycle 39, 36 months, or disease progression, whichever came first. The primary endpoint was progression-free survival (PFS), defined as progression to active MM as assessed by an independent review committee and according to IMWG diagnostic criteria for MM (SLiM-CRAB) or death. Major secondary endpoints included overall response rate (ORR), PFS on first-line MM treatment (PFS2), and overall survival (OS). Results: A total of 390 patients (DARA, n = 194; active monitoring, n = 196) were randomized. Median (range) age (64 [31-86] years) and time from initial SMM diagnosis to randomization (0.72 [0-5.0] years) were balanced between treatment groups. Median treatment duration in the DARA group was 38 cycles (35.0 months). At a median (range) follow-up of 65.2 (0-76.6) months, PFS was significantly improved with DARA versus active monitoring (HR, 0.49; 95% CI, 0.36-0.67; P &lt;0.0001). Median PFS was not reached in the DARA group versus 41.5 months for active monitoring; estimated 60-month PFS rates were 63.1% versus 40.8%, respectively. Prespecified analyses showed generally consistent PFS improvement with DARA versus active monitoring across subgroups. ORR was 63.4% with DARA versus 2.0% with active monitoring (P &lt;0.0001). As of the clinical cutoff, 64 (33.0%) patients in the DARA group and 102 (52.0%) patients in the active monitoring group had started first-line MM treatment. Median time from randomization to the date of first-line MM treatment was not reached with DARA versus 50.2 months with active monitoring (HR, 0.46; 95% CI, 0.33-0.62; nominal P &lt;0.0001). There was a positive trend in favor of DARA for PFS2 (HR, 0.58; 95% CI, 0.35-0.96) and OS (60-month OS rates: DARA, 93.0%; active monitoring, 86.9%; HR, 0.52; 95% CI, 0.27-0.98). A total of 41 deaths were observed, 15 for the DARA group and 26 for the active monitoring group. Grade 3/4 treatment-emergent adverse events (TEAEs) occurred in 40.4% and 30.1% of patients in the DARA and active monitoring groups, respectively. The most common (≥5% in either group) grade 3/4 TEAE was hypertension (DARA, 5.7%; active monitoring, 4.6%). The frequency of TEAEs leading to DARA discontinuation was low (5.7%), as was the incidence of fatal TEAEs in both groups (DARA, 1.0%; active monitoring, 2.0%). Conclusions: DARA monotherapy was well tolerated and demonstrated a clinically meaningful and significant benefit in preventing or delaying progression to active MM compared with active monitoring in patients with high-risk SMM. ORR was significantly higher and time to first-line MM treatment was prolonged with DARA compared with active monitoring. This was accompanied by positive trends for PFS2 and OS in favor of DARA. These results strongly support the benefit of early intervention with DARA monotherapy versus active monitoring, the current standard of care, in patients with high-risk SMM.

Introduction Linvoseltamab is an investigational, BCMA×CD3 bispecific antibody designed for the treatment of RRMM. High objective response rates (ORR) to linvoseltamab 200 mg in the LINKER-MM1 trial (NCT03761108) were demonstrated across high-risk subgroups, including patients aged ≥75 years, patients with high-risk cytogenetics, and patients with penta-class refractory status. The aim of this study was to compare ORR, overall and in key subgroups, between patients in Phase 2 of the LINKER-MM1 trial and patients in an international RW SOC external control arm (ECA). Methods The ECA was derived from a chart review of 16 academic sites across 10 countries that are part of the International Myeloma Foundation (IMF)-International Myeloma Working Group (IMWG) and 2 US electronic health record databases (COTA and Guardian Research Network [GRN]). Included patients initiated ≥1 anti-MM treatment after meeting key eligibility criteria of LINKER-MM1. Weighted random sampling and inverse probability of treatment weighting (IPTW) were used to select 1 line of therapy (LOT) per patient and balance the overall ECA and trial populations on prespecified prognostic factors (Kumar S, et al. IMS 2023). For ORR assessment, LINKER-MM1 and IMF-IMWG used independent central review committees per IMWG criteria, COTA used algorithmic assessment based on IMWG criteria, and GRN used physician-assessed responses. Prior to conducting comparative analyses, an independent committee of epidemiology and oncology experts reviewed the comparability of the cohorts and endpoint assessments, and approved study continuation. ORR among patients in LINKER-MM1 and patients in the ECA was compared overall and across prespecified subgroups (≥10 patients per subgroup), including age, race, cytogenetic risk score, international Staging System (ISS), presence of extramedullary plasmacytoma (EMP), refractory class, bone marrow plasma cell (BMPC) proportion, and number of prior LOTs. Results Median duration of follow-up was 14.3 months (data cut-off: January 6, 2024) for patients receiving linvoseltamab (n=105) and 13.6 months for the ECA (n=307; n=194, n=72, and n=41 from IMF-IMWG, COTA, and GRN, respectively). Following IPTW, 13 prognostic factors with &lt;30% missingness were balanced between cohorts, with an effective sample size in the ECA of 197. After adjustment, ORR was significantly higher in patients who received linvoseltamab compared with patients in the ECA (69.5% vs 45.7%, odds ratio [OR] 2.5 [95% confidence interval (CI) 1.6-4.1]) and in key subgroups with age 65-74 years (76.9% vs 48.3%, OR 3.6 [1.6-8.6]), age ≥75 years (72.4% vs 48.5%, OR 2.8 [1.1-7.4]), Black or African American race (82.4% vs 25.0%, OR 14.0 [3.0-85.4]), White race (68.9% vs 49.7%, OR 2.2 [1.3-4.0]), standard cytogenetic risk (72.3% vs 51.3%, OR 2.5 [1.3-4.8]), ISS stage III (58.8% vs 19.7%, OR 5.8 [1.5-25.2]), absence of EMP (71.6% vs 49.3%, OR 2.6 [1.5-4.6]), triple-class refractory status (68.2% vs 45.7%, OR 2.6 [1.5-4.4]), quadruple-class refractory status (66.7% vs 45.9%, OR 2.4 [1.3-4.3]), 4-5 prior LOTs (65.1% vs 40.4%, OR 2.8 [1.3-6.0]), and &gt;5 prior LOTs (75.7% vs 36.1%, OR 5.5 [2.4-13.6]). Numerically higher (not statistically significant) or similar ORR was observed for patients receiving linvoseltamab compared with patients in the ECA with age &lt;65 years (59.5% vs 46.8%, OR 1.7 [0.79-3.6]), high-risk cytogenetics (65.0% vs 63.1%, OR 1.1 [0.41-2.9]), ISS stage I (73.3% vs 64.6%, OR 1.5 [0.62-3.7]), ISS stage II (67.6% vs 53.5%, OR 1.8 [0.72-4.7]), presence of EMP (58.8% vs 56.9%, OR 1.1 [0.32-3.8]), penta-class refractory status (64.3% vs 48.5%, OR 1.9 [0.78-4.8]), BMPC &lt;50% (77.0% vs 67.2%, OR 1.6 [0.61-4.3]), BMPC ≥50% (41.7% vs 36.0%, OR 1.3 [0.36-4.7]), and ≤3 prior LOTs (68.0% vs 66.4%, OR 1.1 [0.43-2.9]). Separate findings will be presented for IMF-IMWG and COTA/GRN data at the congress. Conclusions Linvoseltamab induced better ORR vs RW SOC treatments overall, and better or similar ORR in the key subgroups assessed, highlighting its therapeutic value across a range of patients with RRMM with heterogeneous risk profiles and levels of disease burden.

7510 Background: The randomized Phase 3 CANOVA study’s (NCT03539744) primary analysis showed multiple numerically improved efficacy endpoints with VenDex v PomDex, but the primary endpoint of mPFS by IRC was not statistically significant. Here, we report correlative biomarker analyses from CANOVA. Methods: CANOVA is a randomized, global, open-label Phase 3 study of VenDex v PomDex in pts with t(11;14)+ RRMM and ≥2 prior lines of therapy (LOTs). The primary endpoint was mPFS by IRC. Key secondary endpoints included ORR, ≥VGPR, mOS, and MRD negativity (<10-5). In post hoc mPFS sensitivity analysis, disease progression, death, and start of next LOT were defined as events. BCL2 gene expression by RNAseq (3.7 log2 FPKM prespecified median cutoff for BCL2high v BCL2low) and chr1q abnormalities by whole-exome sequencing (normal, gain, or amp) were assessed centrally from pretreatment, CD138-enriched BM aspirates. Results: mPFS, post hoc mPFS, and mOS in the VenDex arm were similar by BCL2 status, with numerically higher ORR, ≥VGPR, and MRD negativity rates in the BCL2highsubgroup. In contrast, mPFS and mOS within the PomDex arm were numerically longer in the BCL2lowsubgroup, despite equal ORR in both subgroups (Table). Presence of 1q abnormalities was evenly distributed across BCL2high v BCL2low subgroups in the VenDex arm (51% v 45%) but not in the PomDex arm (59% v 31%). Normal 1q and gain(1q) subgroups had numerically improved mPFS, mOS, ORR, ≥VGPR, and MRD negativity with VenDex; pts with amp(1q) had poor outcomes regardless of treatment, albeit the sample size was small. Conclusions: Pts with BCL2high or gain(1q) had numerically improved clinical efficacy with VenDex v PomDex. Clinical benefit was consistent across BCL2 subgroups ( BCL2high or BCL2low) with VenDex but not PomDex. Pts with amp(1q) fared poorly irrespective of treatment arm. Clinical trial information: NCT03539744 . [Table: see text]

PURPOSE At the primary analysis of CASTOR (median follow-up, 7.4 months), daratumumab plus bortezomib and dexamethasone (D-Vd) significantly prolonged progression-free survival versus bortezomib and dexamethasone (Vd) alone in relapsed or refractory multiple myeloma (RRMM). We report updated efficacy and safety results at the final analysis for overall survival (OS). METHODS CASTOR was a multicenter, randomized, open-label, phase III study during which eligible patients with ≥ 1 line of prior therapy were randomly assigned to Vd (up to eight cycles) with or without daratumumab (until disease progression). After positive primary analysis and protocol amendment, patients receiving Vd were offered daratumumab monotherapy after disease progression. RESULTS At a median (range) follow-up of 72.6 months (0.0-79.8), significant OS benefit was observed with D-Vd (hazard ratio, 0.74; 95% CI, 0.59 to 0.92; P = .0075). Median OS was 49.6 months with D-Vd versus 38.5 months with Vd. Prespecified subgroup analyses demonstrated an OS advantage with D-Vd versus Vd for most subgroups, including patients age ≥ 65 years and patients with one or two prior lines of therapy, International Staging System stage III disease, high-risk cytogenetic abnormalities, and prior bortezomib treatment. The most common (≥ 10%) grade 3/4 treatment-emergent adverse events with D-Vd versus Vd were thrombocytopenia (46.1% v 32.9%), anemia (16.0% v 16.0%), neutropenia (13.6% v 4.6%), lymphopenia (10.3% v 2.5%), and pneumonia (10.7% v 10.1%). CONCLUSION D-Vd significantly prolonged OS in patients with RRMM, with the greatest OS benefit observed in patients with one prior line of therapy. To our knowledge, our results, together with the OS benefit observed with daratumumab plus lenalidomide and dexamethasone in the phase III POLLUX study, demonstrate for the first time an OS benefit with daratumumab-containing regimens in RRMM (ClinicalTrials.gov identifier: NCT02136134 [CASTOR]).