Belantamab mafodotin, pomalidomide and dexamethasone in refractory multiple myeloma: a phase 1/2 trial.

Due to evolving treatment standards for newly diagnosed multiple myeloma, many patients will be triple-class exposed after initial relapses and have poor survival. Novel therapies and combinations are therefore required to improve outcomes. B cell maturation antigen (BCMA)-targeted biologics have emerged as an important new area of therapeutics for relapsed multiple myeloma. The two-part ALGONQUIN trial evaluated various doses and schedules of the anti-BCMA antibody-drug conjugate belantamab mafodotin plus pomalidomide and dexamethasone for patients who are lenalidomide refractory and proteosome inhibitor exposed. The primary endpoints, including evaluating dose-limiting toxicities, establishing the recommended Part 2 dose (RP2D) and overall response rate for patients treated at the RP2D, were met. Secondary efficacy endpoints included progression-free survival and overall survival. Patients treated on study (N = 87) had a median of three previous regimens and 55.2% were triple-class refractory. At the RP2D the most common adverse events were decrease in best-corrected visual acuity (71.1%), keratopathy (65.8%), fatigue (57.9%), infection (47.4%; 7.9% grade ≥3), neutropenia (39.5%) and thrombocytopenia (39.5%). For RP2D patients (n = 38), the overall response rate was 85.3%, ≥very good partial response 75.7% and estimated two-year progression-free survival 52.8% (95% confidence interval, 33.9% to 82.4%), at a median follow-up of 13.9 months. The RP2D schedule was associated with manageable antibody-drug conjugate-associated corneal adverse events and improved tolerability without compromising efficacy. Belantamab mafodotin plus pomalidomide and dexamethasone induced durable responses with promising overall survival in relapsed multiple myeloma, the results of which are yet to be confirmed in the phase 3 DREAMM-8 study. ClinicalTrials.gov Identifier: NCT03715478 .

Daratumumab for patients with myeloma with early or late relapse after initial therapy: subgroup analysis of CASTOR and POLLUX.

ABSTRACT: High-risk multiple myeloma (MM) is often defined based on cytogenetic abnormalities, but patients who relapse early after initial therapy are considered a functional high-risk group. In the phase 3 CASTOR and POLLUX studies, daratumumab plus bortezomib/dexamethasone (D-Vd) or lenalidomide/dexamethasone (D-Rd) improved progression-free survival (PFS) and overall survival (OS), regardless of cytogenetic risk, and achieved higher rates of complete response or better (≥CR) and minimal residual disease (MRD) negativity vs that with Vd/Rd alone in relapsed/refractory MM. Post hoc analyses of CASTOR and POLLUX evaluated patient subgroups with 1 prior line of therapy based on timing of progression/relapse (early or late) after initiation of first line of therapy. PFS consistently favored the daratumumab-containing regimens across subgroups using both a 24- and 18-month early-relapse cutoff. In the CASTOR/POLLUX pooled data set, daratumumab reduced the risk of disease progression or death by 65% (hazard ratio [HR], 0.35; 95% confidence interval [CI], 0.26-0.48; P < .0001) in the early-relapse (<24 months) subgroup and by 65% (HR, 0.35; 95% CI, 0.26-0.47; P < .0001) in the late-relapse (≥24 months) subgroup. OS also favored the daratumumab-containing regimens in both the early-relapse (HR, 0.62; 95% CI, 0.45-0.86; P = .0036) and late-relapse (HR, 0.67; 95% CI, 0.48-0.93; P = .0183) subgroups in the pooled population using a 24-month cutoff. Rates of ≥CR and MRD negativity (10-5) were higher with daratumumab vs control, regardless of progression/relapse timing. Although daratumumab is unable to fully overcome the adverse prognosis of early relapse, our results support the use of daratumumab for patients with 1 prior line of therapy, including for those who progress/relapse early after initial therapy and are considered to have functional high-risk MM. These trials were registered at www.clinicaltrials.gov as #NCT02136134 (CASTOR) and #NCT02076009 (POLLUX).

Real-world results of autologous stem cell transplantation in newly diagnosed multiple myeloma: a report from the Canadian Myeloma Research Group database.

Autologous stem cell transplant (ASCT) remains an important option for eligible multiple myeloma (MM) patients as part of initial therapy. Using the Canadian Myeloma Research Group (CMRG) national database, we examined the details and outcomes of ASCT performed as first-line therapy in eligible Canadian MM patients between 2007 to 2021. We included 3821 patients with 72% receiving CyBorD induction and 2061 patients receiving maintenance, consisting of lenalidomide +/- steroids in 78.3%. The median PFS and OS for patients given a single ASCT were 35.4 and 126 months. Those receiving a second induction regimen had significantly inferior outcomes, although when maintenance was used, results were comparable regardless of the number of induction regimens administered (median PFS 55.3 vs 51.1 months [p = 0.11]; median OS 158.6 vs not yet reached [p = 0.13]). Consolidation patients had a longer median PFS (55.3 vs 34.4 months [p = 0.001]), but no significant gain in median OS (p = 0.065). Patients who received lenalidomide-based maintenance experienced a median PFS of 53.7 months and OS of 159 months. In the multivariable analysis, use of any type of maintenance therapy vs no maintenance was associated with a lower risk of progression (HR 0.52 (95% CI 0.47-0.57)) and death (HR 0.58 (95% CI 0.51-0.67)). This real-world study demonstrates that, overall, first-line treatment sequence in transplant-eligible patients produces a median OS of ≥10 years. It also highlights the contribution of post-ASCT maintenance, particularly lenalidomide given until progression.

The Impact of CD34+ Cell Collection Yields for Autologous Transplant on Survival Outcomes in Multiple Myeloma.

INTRODUCTION: According to previous data, higher yields of stem-cells collected to support autologous transplantation may predict for improved outcomes. We aimed to assess the association between high stem-cells collection and survival outcomes in multiple myeloma (MM) MATERIALS AND METHODS: We reviewed all patients who underwent autologous transplantation for MM at our center over a 10-year period, and initially used a predefined threshold of 8 × 106/kg used in previous studies. RESULTS: Six hundred twenty-one patients were analyzed. Higher mobilization did not correlate with favorable outcomes post-transplant. The most efficient mobilizers, collecting ≥8 × 106/kg (n = 478) achieved a shorter median progression-free survival (PFS) of 24.1m versus 34.5m in patients collecting 4.5 to 8 × 106/kg (n = 129). A small group (n = 14) collecting ≤4.5 × 106/kg but minimum of 2 × 106/kg to support autologous transplantation exhibited the worst outcomes (median PFS 11.4m). Further analysis of potential confounders identified greater use of bortezomib induction in the lower mobilizers, however, sensitivity analysis in patients receiving bortezomib revealed similar results- worst outcomes to the most efficient mobilizers. CONCLUSION: Although bortezomib is not considered stem-cell toxic, it may be associated with lower stem cell collection yields. Bortezomib's efficacy at induction may partially explain the improved outcomes, however, other factors may be involved, and are discussed. We can conclude that with our large cohort and long follow-up, high stem-cell mobilization does not appear to predict for a long-term survival advantage.

Outcome of carfilzomib/pomalidomide-based regimens after daratumumab-based treatment in relapsed multiple myeloma: A Canadian Myeloma Research Group Database analysis.

INTRODUCTION: Although daratumumab-containing regimens improve multiple myeloma (MM) outcomes, recurrence is inevitable. METHODS AND OBJECTIVE: We performed a retrospective study using the Canadian Myeloma Research Group Database to benchmark the efficacy of carfilzomib- or pomalidomide-based therapies immediately following progression on daratumumab treatment. RESULTS: We identified 178 such patients; median number of prior lines of therapy was 3, 97% triple-class exposed, and 60% triple-class refractory. In our cohort, 75 received a subsequent carfilzomib-based therapy, 79 received a pomalidomide-based therapy, and 24 received a treatment with both immunomodulatory drug (IMiD) and proteasome inhibitor (PI) using carfilzomib and/or pomalidomide. The median progression-free survival (PFS) and overall survival (OS) for the entire cohort were 4.5 and 14.2 months, respectively. Carfilzomib-based therapy yielded a median PFS and OS of 4.5 and 10.2 months, respectively, compared to 5.2 and 21.7 months for pomalidomide-based therapy. Patients who received both IMiD and PI with carfilzomib and/or pomalidomide had a median PFS and OS of 4.1 and 14.5 months, respectively. CONCLUSION: Our observations demonstrate the poor outcome of MM patients when standard regimens based on carfilzomib and/or pomalidomide are utilized directly after daratumumab-based therapy given in the relapsed setting. Novel therapies, including immune therapies, are urgently needed to improve the outcomes of these daratumumab-exposed patients.

How should multiple myeloma research change in a patient-oriented world? Findings and lessons from the pan-Canadian myeloma priority setting partnership.

BACKGROUND: Over the last decade there has been considerable research into the treatment, management, and quality of life of people living with multiple myeloma. However, there has been limited investigation into topics deemed important to patients and caregivers within this community. We conducted a James Lind Alliance Priority Setting Partnership to establish the 'Top 10 Priorities for Myeloma Research', informed by patient and public partners. METHODS: A research team and steering group were established in 2019 to conduct the myeloma priority setting partnership. Steering group members included patients, caregivers, and healthcare providers who advised the research team and oversaw the scope of the project, grounded on their lived experience. Following the James Lind Alliance guidelines for identification and ranking of research questions, we used surveys and a virtual workshop to collect and prioritize questions posed by myeloma patients, caregivers, and healthcare providers across Canada. RESULTS: The Top 10 list of priorities for myeloma research was finalized at the consensus-building workshop and encompassed questions related to diagnosis, treatment, management, and living well with myeloma. A final participant evaluation survey elicited a positive response. INTERPRETATION: The myeloma priority setting partnership identified the research priorities of people living with myeloma, caregivers, and healthcare providers to inform clinical research on this disease going forward. This project underscores the importance of patient and public engagement in the identification of research questions, highlighting the concerns of people affected by myeloma to ultimately improve the lives of people living with this disease.

Research on multiple myeloma, a rare blood cancer, rarely focuses on topics that are personally important to people living with myeloma, their caregivers, and their healthcare providers. The purpose of this study was to complete a priority setting partnership, following guidelines from the James Lind Alliance, to identify unanswered research questions from people directly affected by myeloma. The project was guided by a steering group of people living with myeloma, their caregivers, and healthcare providers who informed all stages of this process including two questionnaires to collect and rank questions and a priority setting workshop. The workshop brought together representatives from each group to form the final 'Top 10 Priorities for Myeloma Research', which included questions related to diagnosis, treatment, management, and living well with myeloma. This process allowed us to identify the research priorities of the myeloma community and highlighted the importance of including patients and the public as team members in the research process. We encourage other myeloma researchers to do the same to ensure research is meaningful and relevant to the communities who rely on it.

Redefining attrition in multiple myeloma (MM): a Canadian Myeloma Research Group (CMRG) analysis.

While most patients diagnosed with multiple myeloma (MM) receive initial therapy, reported attrition rates are high. Understanding attrition rates and characteristics of patients not receiving subsequent therapy is useful for MM stakeholders. We performed an analysis of attrition rates in a large disease-specific database of patients with newly diagnosed MM who received at least one line of therapy between Jan 1/10-Dec 31/20. Attrition was defined as failure to receive a subsequent line of therapy despite progression of MM or due to death. A total of 5548 patients were identified, 3111 autologous stem cell transplant (ASCT) patients and 2437 non-ASCT. In the ASCT cohort, the attrition rate was 7% after line 1, 12% after line 2, and 23% after line 3. In non-ASCT patients, the attrition rate was 19% after line 1, 26% after line 2, and 40% after line 3. Death was the dominant contributor to attrition across all cohorts, with a minority of patients alive with progressive disease in the absence of further therapy at each line. Multivariable analysis identified older age, shorter time to progression, and inferior response as independent risk factors for attrition. Our data show that attrition rates increase with each line of therapy and are higher in non-ASCT patients but are appreciably lower than previously reported. This study supports a revision of the previous definition of attrition, demonstrating that most patients who do not receive subsequent therapy are either continuing their current therapy and/or are in remission off-treatment rather than being irreversibly lost to attrition.

A Phase II, Open-Label Study of an Accelerated Infusion Rate of Daratumumab in Patients With Relapsed and Refractory Multiple Myeloma.

INTRODUCTION/BACKGROUND: Daratumumab is an anti-CD38 monoclonal antibody initially approved as a single agent for the treatment of relapsed and refractory multiple myeloma. The infusion-related reactions (IRRs) commonly seen with intravenous daratumumab have been managed by prolonging the first infusion, temporarily stopping/slowing the rate if reactions occur and using adequate pre- and post-infusion medications. Several retrospective studies have evaluated shorter infusions after ≥ 2 prior doses administered at the standard rates. Although the shorter infusions were well-tolerated, patients in these reports were given heterogeneous daratumumab regimens and had often already received multiple doses at the longer standard rates. PATIENTS AND METHODS: CMRG-009 is a prospective study designed to demonstrate the safety of accelerated daratumumab infusions commencing with the second dose. After an initial dose on Cycle 1 Day consisting of 8 mg/kg over 4 hours, all subsequent doses were given over 90 minutes. RESULTS: No grade 3 IRRs were observed with the 90-minutes infusions. Both the safety profile and anti-myeloma effects were otherwise similar to those observed with other single agent daratumumab studies using longer infusion times. CONCLUSION: This is the first formal prospective trial using infusion times shorter than the standard schedule directly after an initial 4-hours dose. This rapid infusion protocol has resulted in more efficient resource utilization and has become the standard protocol for the use in all intravenous daratumumab regimens in Canada. This approach has been particularly helpful in shortening chair time during the COVID-19 pandemic and providing a useful alternative in jurisdictions without access to subcutaneous daratumumab.

Clinical evidence for immune-based strategies in early-line multiple myeloma: current challenges in decision-making for subsequent therapy.

Almost all patients with multiple myeloma (MM) will eventually develop disease that has relapsed with or become refractory to available treatments and will require additional therapy. However, data are still lacking on how best to sequence regimens in the relapsed/refractory (RR) setting after the failure of early-line lenalidomide, bortezomib, and/or daratumumab, the most commonly used agents in clinical practice today. With the treatment landscape rapidly changing in response to emerging clinical trial data and approvals of several new drugs and additional combinations, it is critically important to focus on patients with RRMM. Variability in patient baseline characteristics, such as the number of prior lines of treatment, refractoriness to prior treatments, prior stem cell transplant, and timing and dosing of prior lenalidomide, makes it difficult to select the best options for patients with RRMM for whom first-line treatments have failed. The aim of this review is to provide both an overview of current therapies and future directions within the RRMM treatment landscape, and a framework for clinicians to choose the most promising next treatment option.

Phase 1/2 study of carfilzomib, pomalidomide, and dexamethasone with and without daratumumab in relapsed multiple myeloma.

We conducted a phase 1/2 study of carfilzomib, pomalidomide, and dexamethasone (KPd) and KPd with daratumumab (Dara-KPd) in relapsed/refractory multiple myeloma. The primary end points were identification of a maximum tolerated dose (MTD) of KPd for phase 1, and rates of overall response (ORR) and near complete response (nCR) after 4 cycles of KPd and Dara-KPd, respectively, for phase 2. The MTD for KPd was carfilzomib 20/27 mg/m2 on days 1, 2, 8, 9, 15, and 16 (cycles 1-8) and days 1, 2, 15, and 16 for cycles 9 and beyond; oral pomalidomide 4 mg on days 1 to 21; and oral dexamethasone 40 mg weekly in 28-day cycles. Sixty-six patients received KPd, including 34 at the MTD. The ORR after 4 cycles of KPd at the MTD was 27/34 (79%; 95% confidence interval [CI], 62%-91%), meeting the statistical threshold for efficacy. At a median follow-up of 44 months, the median progression-free survival (PFS) was 13 months and overall survival (OS) 44 months. Twenty-eight patients received Dara-KPd. The rate of nCR or better after 4 cycles was 11/28 (39%; 95% CI, 22%-59%), meeting the statistical threshold for efficacy. As the best response to Dara-KPd, the ORR was 25/28 (89%) and the rate of measurable residual disease negativity by flow cytometry (10-5) was 17/26 (65%). At a median follow-up of 26 months, the median PFS and OS for Dara-KPd were not reached. Dara-KPd induced deeper and more durable responses than KPd without compromising safety in a predominantly high-risk, lenalidomide-refractory population, warranting further evaluation of this quadruplet. This trial is registered at www.clinicaltrials.gov as #NCT01665794.

Overall Survival With Daratumumab, Lenalidomide, and Dexamethasone in Previously Treated Multiple Myeloma (POLLUX): A Randomized, Open-Label, Phase III Trial.

PURPOSE: With the initial analysis of POLLUX at a median follow-up of 13.5 months, daratumumab in combination with lenalidomide and dexamethasone (D-Rd) significantly prolonged progression-free survival versus lenalidomide and dexamethasone (Rd) alone in patients with relapsed or refractory multiple myeloma (RRMM). We report updated efficacy and safety results at the time of final analysis for overall survival (OS). METHODS: POLLUX was a multicenter, randomized, open-label, phase III study during which eligible patients with ≥ 1 line of prior therapy were randomly assigned 1:1 to D-Rd or Rd until disease progression or unacceptable toxicity. After positive primary analysis and protocol amendment, patients receiving Rd were offered daratumumab monotherapy after disease progression. RESULTS: Significant OS benefit was observed with D-Rd (hazard ratio, 0.73; 95% CI, 0.58 to 0.91; P = .0044) at a median (range) follow-up of 79.7 months (0.0-86.5). The median OS was 67.6 months for D-Rd compared with 51.8 months for Rd. Prespecified analyses demonstrated an improved OS with D-Rd versus Rd in most subgroups, including patients age ≥ 65 years and patients with one, two, or three prior lines of therapy, International Staging System stage III disease, high-risk cytogenetic abnormalities, and refractoriness to their last prior line of therapy or a proteasome inhibitor. The most common (≥ 10%) grade 3/4 treatment-emergent adverse events with D-Rd versus Rd were neutropenia (57.6% v 41.6%), anemia (19.8% v 22.4%), pneumonia (17.3% v 11.0%), thrombocytopenia (15.5% v 15.7%), and diarrhea (10.2% v 3.9%). CONCLUSION: D-Rd significantly extended OS versus Rd alone in patients with RRMM. To our knowledge, for the first time, our findings, together with the OS benefit observed with daratumumab plus bortezomib and dexamethasone in the phase III CASTOR trial, demonstrate OS improvement with daratumumab-containing regimens in RRMM (ClinicalTrials.gov identifier: NCT02076009 [POLLUX]).

Myeloma immunoglobulin rearrangement and translocation detection through targeted capture sequencing.

Multiple myeloma is a plasma cell neoplasm characterized by clonal immunoglobulin V(D)J signatures and oncogenic immunoglobulin gene translocations. Additional subclonal genomic changes are acquired with myeloma progression and therapeutic selection. PCR-based methods to detect V(D)J rearrangements can have biases introduced by highly multiplexed reactions and primers undermined by somatic hypermutation, and are not readily extended to include mutation detection. Here, we report a hybrid-capture approach (CapIG-seq) targeting the 3' and 5' ends of the V and J segments of all immunoglobulin loci that enable the efficient detection of V(D)J rearrangements. We also included baits for oncogenic translocations and mutation detection. We demonstrate complete concordance with matched whole-genome sequencing and/or PCR clonotyping of 24 cell lines and report the clonal sequences for 41 uncharacterized cell lines. We also demonstrate the application to patient specimens, including 29 bone marrow and 39 cell-free DNA samples. CapIG-seq shows concordance between bone marrow and cfDNA blood samples (both contemporaneous and follow-up) with regard to the somatic variant, V(D)J, and translocation detection. CapIG-seq is a novel, efficient approach to examining genomic alterations in myeloma.

Post Salvage Therapy Autologous Transplant for Relapsed Myeloma, Ongoing Relevance within Modern Treatment Paradigms?

BACKGROUND: Salvage transplant has been historically considered effective therapy for myeloma patients relapsing after first transplant, if they achieved adequate remission duration. However, the efficacy of novel agent combinations has called this paradigm into question. MATERIALS AND METHODS: We performed a retrospective analysis in a homogeneously treated cohort of 106 patients undergoing ASCT2 at our institution, all of whom received novel agent-based chemotherapy (immunomodulatory agent [IMiD] and/or proteasome inhibitor [PI]) for both induction and relapse. As an exploratory objective we assessed whether predictive thresholds of progression free survival post first transplant (ASCT1) for benefit post ASCT2 vary with use of IMiD maintenance post ASCT1. RESULTS: The overall response rate (ORR) was 98% post-ASCT2 and treatment-related mortality (TRM) was low at 1.8%. With a median follow-up of 26 months (range 0.5-85) from ASCT2, median overall survival (OS) is estimated at 80 months (95% CI: ≥ 49-months) and median progression-free survival after ASCT2 (PFS2) at 24 months (95% CI 19-39). PFS post first transplant (PFS1) at >/= 50 months was associated with improved OS. Predictors of PFS2 included PFS1 ≤42 months and progression on IMiD-based maintenance post- ASCT1. CONCLUSION: ASCT2 continues to offer acceptable outcomes for most patients treated within modern day treatment paradigms, with longer PFS after ASCT1 and IMiD non-refractory disease being associated with improved outcomes.

Real-world data on lenalidomide dosing and outcomes in patients newly diagnosed with multiple myeloma: Results from the Canadian Myeloma Research Group Database.

Using the Canadian Myeloma Research Group Database, a retrospective study of 167 newly diagnosed, transplant-ineligible patients with multiple myeloma (MM) that received lenalidomide-dexamethasone as front-line treatment was conducted to understand the impact of lenalidomide dosing. Starting dose modifications were common, 42% of patients started on lenalidomide <25 mg with normal renal function. During treatment course, 35% of patients required further dose reduction. Dose reductions in the first year did not have an impact on progression free survival or overall survival. Further studies need to be conducted to understand the impact of dosing strategies of anti-MM agents in the real world.

Understanding real-world treatment patterns and clinical outcomes in AL amyloidosis patients diagnosed in Canada: A population-based cohort study.

Amyloid light chain (AL) amyloidosis is a rare and chronic bone marrow disorder. Existing claims data can be used to help understand the real-world treatment patterns and outcomes of this patient population. Various population-based administrative databases in Alberta, Canada were queried from 2010 to mid-2019 to identify cases of AL amyloidosis. Baseline patient and disease characteristics, sequencing of pharmacologic therapies, overall survival, and healthcare resource utilization were evaluated. A total of 215 individuals with AL amyloidosis were included. Among patients diagnosed between 2012 and 2019, 149 (85.1%) initiated first-line, 67 (38.3%) initiated second-line, 22 (12.6%) initiated third-line, and 11 (6.3%) initiated fourth-line systemic therapy. In the first-line setting, 99/149 (66.4%) received bortezomib, cyclophosphamide, and dexamethasone (CyBorD) and 21/149 (14.1%) received another bortezomib-based regimen. Survival from time of diagnosis improved over time, with a median overall survival of 25.8 months (95% CI: 9.8, 57.1) for individuals diagnosed in 2010-2011 versus 52.1 months (95% CI: 25.6, NA) for those diagnosed in 2012-2019. Despite this improvement, the proportion of individuals diagnosed in 2012-2019 who survived beyond five-years remained low (5-year survival: 48.4%; 95% CI: 40.9, 57.2) which highlights an unmet need for more efficacious therapies.

Carfilzomib usage patterns and outcomes in patients with relapsed multiple myeloma: A multi-institutional report from the Canadian Myeloma Research Group (CMRG) Database.

Carfilzomib is an active and commonly used treatment in patients with multiple myeloma (MM). Using the Canadian Myeloma Research Group Database, we performed a retrospective observational study of patients treated with carfilzomib for relapse of MM in a real-world setting in Canada between years 2007 and 2020. A total of 445 patients were included in this study: the doublet (Kd/p, n = 218) and triplets (KCd, n = 88; KRd, n = 99; KPd/p, n = 40). One hundred and twenty-two (27%) received carfilzomib-based treatment in line 2, 133 (30%) in line 3, 90 (20%) in line 4, and 100 (23%) in line 5 or higher. Carfilzomib was dosed weekly in 40% of patients and twice weekly in 60%. The overall response rate of the entire cohort was 57.7%, with 33.6% of patients achieving very good partial response or better. Median progression-free survival for the overall cohort was 6.3 months with overall survival 19.7 months. This study provides a benchmark for carfilzomib-based regimens in the real world, demonstrating that these regimens are effective in treating patients with relapsed MM.

Addition of elotuzumab to lenalidomide and dexamethasone for patients with newly diagnosed, transplantation ineligible multiple myeloma (ELOQUENT-1): an open-label, multicentre, randomised, phase 3 trial.

BACKGROUND: Elotuzumab plus lenalidomide and dexamethasone has shown improved progression-free and overall survival versus lenalidomide and dexamethasone in patients with relapsed or refractory multiple myeloma. We aimed to assess these regimens in patients with newly diagnosed multiple myeloma who are ineligible for haematopoietic stem-cell transplantation (HSCT). METHODS: ELOQUENT-1 is an open-label, multicentre, randomised, phase 3 trial conducted at 185 hospitals, oncology practices, and research centres in 19 countries. Eligible patients were aged 18 years or older with newly diagnosed, untreated, symptomatic myeloma and not candidates for high-dose therapy plus HSCT, and an Eastern Cooperative Oncology Group (ECOG) performance status of 2 or lower. Patients were randomly assigned (1:1) to receive elotuzumab plus lenalidomide and dexamethasone or lenalidomide and dexamethasone using an interactive voice response system, stratified by the International Staging System (ISS; stage I-II vs III), age (<75 years vs ≥75 years), and ECOG performance status (0 vs 1-2). Patients in the elotuzumab plus lenalidomide and dexamethasone group received elotuzumab administered intravenously at 10 mg/kg on days 1, 8, 15, and 22 during cycles 1 and 2, days 1 and 15 during cycles 3-18, and then at 20 mg/kg on day 1 for subsequent cycles. In both treatment groups, patients received 25 mg lenalidomide orally on days 1-21 of each cycle and 40 mg dexamethasone on days 1, 8, 15, and 22 of each cycle. The primary endpoint was progression-free survival, as per the primary definition from European Society for Blood and Marrow Transplantation criteria in all randomly assigned patients (intention-to-treat population). This study is registered with ClinicalTrials.gov, NCT01335399 (completed). FINDINGS: Between Aug 4, 2011, and June 19, 2014, 748 patients were randomly assigned (374 in each treatment group) and 742 patients received treatment (333 (90%) of 371 in the elotuzumab plus lenalidomide and dexamethasone group vs 339 (91%) of 371 in the lenalidomide and dexamethasone group discontinued treatment). The median age of patients was 73·0 years (IQR 69·0-78·0), 294 (39%) patients were 75 years or older. Most patients were White (711 [95%]) and male (412 [55%]). At a minimum follow-up of 65·3 months, the median progression-free survival was not significantly different between the groups: 31·4 months (95% CI 26·2-36·8) in the elotuzumab plus lenalidomide and dexamethasone group versus 29·5 months (23·5-34·3) in the lenalidomide and dexamethasone group (HR 0·93, 95·71% CI 0·77-1·12; stratified log-rank p=0·44). The median follow-up was 70·6 months (IQR 35·1-79·2). The most common grade 3-4 treatment-related adverse event was neutropenia (64 [17%] of 371 vs 79 [21%] of 371). Study drug toxicity was the reported cause of death in five (1%) versus four (1%) patients. INTERPRETATION: Elotuzumab plus lenalidomide and dexamethasone did not significantly improve progression-free survival versus lenalidomide and dexamethasone in patients with newly diagnosed multiple myeloma who are ineligible for HSCT. Although these data contribute to the treatment landscape, further research is needed to find ways to improve treatments in the front-line setting. FUNDING: Bristol Myers Squibb.