Karlin, Lionel

PURPOSE In immunoglobulin light chain (AL) amyloidosis, amyloid fibrils cause organ dysfunction. Anselamimab, a monoclonal antibody, selectively binds to amyloid fibrils, accelerating their clearance. METHODS Newly diagnosed patients with European modification of Mayo 2004 stage IIIa or IIIb AL amyloidosis were randomly assigned to receive anselamimab or placebo with cyclophosphamide, bortezomib, and dexamethasone (with or without daratumumab). The primary end point was a hierarchical composite of time to all-cause mortality (ACM) and frequency of cardiovascular hospitalizations (CVHs), analyzed using the Finkelstein-Schoenfeld test and win ratio estimation. RESULTS Among 406 randomly assigned patients, the primary end point win ratio for anselamimab versus placebo was 1.11 (95% CI, 0.83, 1.50; P = .332) and the hazard ratio (HR) for ACM was 0.80 (95% CI, 0.57, 1.13; P = .290). CVH rates in the anselamimab and placebo groups were 0.59 (95% CI, 0.42, 0.83) and 0.89 (95% CI, 0.55, 1.43), respectively ( P = .145). Among patients with kappa isotype (n = 72), the win ratio was 2.06 (95% CI, 0.98, 4.31; P = .100) and anselamimab reduced ACM by 62% versus placebo (HR, 0.38; 95% CI, 0.17 to 0.86; nominal P = .012), and CVH by 71% (IRR, 0.29; 95% CI, 0.10 to 0.87; nominal P = .028) with improvements in Kansas City Cardiomyopathy Questionnaire-Overall Score. There was no clinical benefit observed in the lambda population. Anselamimab was generally well-tolerated; safety data were comparable between treatment arms overall. CONCLUSION Treatment with anselamimab, an antifibril antibody used alongside antiplasma cell dyscrasia therapy, while not meeting the primary end point in the overall population, significantly improved ACM and CVH in patients with kappa AL, potentially offering a new therapeutic option for this isotype.

ABSTRACTObjectivesThis final post hoc analysis evaluated patient‐reported outcomes from the Phase 3 MAIA study of daratumumab, lenalidomide, and dexamethasone (D‐Rd) versus lenalidomide and dexamethasone (Rd) after median 64.5‐month follow‐up in transplant‐ineligible patients with newly diagnosed multiple myeloma (NDMM), including patient subgroups.MethodsKey scales from the EORTC QLQ‐C30 (global health status [GHS], physical functioning, pain, and fatigue) were assessed. Scores were evaluated every 3 months for 1 year, then every 6 months until disease progression.ResultsThe intent‐to‐treat population (n = 737) included 46.3% frail, 35.4% 70 to < 75 years old, and 43.6% ≥ 75 years old. D‐Rd‐treated patients showed improvements from baseline that were sustained over 5 years in the intent‐to‐treat population and across subgroups by age, frailty, and bone lesions. Greater proportions of patients treated with D‐Rd versus Rd achieved minimally important changes for improvement at cycle 36 (year ~3) in GHS (odds ratio, 1.84 [95% CI, 1.16–2.91]), physical functioning (1.93 [1.18–3.14]), pain (1.41 [0.90–2.22]), and fatigue (2.00 [1.24–3.23]). Greater proportions of patients with bone lesions improved with D‐Rd versus Rd on GHS and physical functioning.ConclusionsIn transplant‐ineligible patients with NDMM, D‐Rd improved health‐related quality of life over a 5‐year period versus Rd. Trial Registration: ClinicalTrials.gov: NCT02252172

Introduction: Cilta-cel is approved in the US and EU for the treatment (tx) of patients (pts) with len-refractory MM after ≥1 line based on the randomized, phase 3 CARTITUDE-4 trial (NCT04181827). At the first interim analysis (15.9-month [mo] median follow-up), cilta-cel significantly improved progression-free survival (PFS) vs SoC (hazard ratio [HR], 0.26 [protocol-specified weighted analysis]; P&lt;0.0001). At the second interim analysis, overall survival (OS) was significantly improved with cilta-cel vs SoC (HR, 0.55; P=0.0009). MRD negativity is a prognostic marker of prolonged survival outcomes for pts with MM. We report MRD negativity, including overall and sustained MRD negativity, overall MRD-negative complete response or better (≥CR), and MRD-negative ≥CR at mo 12, from the prespecified second interim analysis of CARTITUDE-4. Methods: Eligibility criteria were previously described. Pts were assigned 1:1 to cilta-cel or SoC (pomalidomide, bortezomib, and dexamethasone [PVd]/daratumumab, pomalidomide, and dexamethasone [DPd]). Pts in the cilta-cel arm underwent apheresis, received bridging therapy (PVd/DPd), and then a single cilta-cel infusion (target dose, 0.75×106 CAR+ viable T cells/kg) 5-7 days (d) after the start of lymphodepletion. PFS was the primary endpoint; ≥CR rate, overall response rate, overall MRD-negativity rate, and OS were key secondary endpoints. MRD was assessed centrally via next-generation sequencing (clonoSEQ v2.0; Adaptive Biotechnologies). MRD was evaluated at d 56 post infusion in the cilta-cel arm; and in both arms at suspected ≥CR and at 6, 12, 18, and 24 mo post infusion (cilta-cel arm) or cycle 1 d 1 (SoC arm), as well as yearly until progression/start of subsequent therapy in pts in ≥CR. Sustained MRD negativity (10−5) was defined as confirmed MRD negativity ≥12 mo apart and without MRD positivity in between. Pts were evaluable for sustained MRD negativity if they achieved MRD negativity and had ≥1 evaluable MRD sample ≥12 mo after the first negative result or progressed/died/started subsequent tx &lt;12 mo after the first negative result. Results: 419 pts were randomized (intent-to-treat [ITT] set; cilta-cel, n=208; SoC, n=211); 176 pts in the cilta-cel arm received cilta-cel as study tx. As of May 1, 2024, median follow-up for the study was 33.6 mo. At the 10−5 threshold, 145 pts in the cilta-cel arm and 103 in the SoC arm were evaluable for MRD. MRD-negativity rates (10−5) in the ITT set and the MRD-evaluable subset were higher with cilta-cel vs SoC (ITT, 62% vs 18%; MRD evaluable, 89% vs 38%; both P&lt;0.0001). Across subgroups, cilta-cel vs SoC consistently increased overall MRD-negativity rates (10−5). In the ITT set, 48% of the cilta-cel arm achieved MRD negativity (10−5) by d 56, with the MRD-negative rate rising to 60% by 6 mo post cilta-cel infusion. Overall MRD-negativity rates at the 10−6 threshold in the ITT set were higher with cilta-cel vs SoC (57% vs 9%; P&lt;0.0001). In the cilta-cel arm, 119 (57%) pts vs 26 (12%) in the SoC arm achieved overall MRD-negative (10−5) ≥CR (P&lt;0.0001). At the 12-mo MRD assessment, 92 (44%) pts in the cilta-cel arm vs 17 (8%) in the SoC arm (P&lt;0.0001) had MRD-negative (10−5) ≥CR. In pts with MRD-negative (10−5) ≥CR at mo 12, median PFS was not reached (NR; 95% CI, not estimable [NE]-NE) with cilta-cel and 37.8 mo (95% CI, 25.0-NE) with SoC; median OS was NR (95% CI, NE-NE) and NR (95% CI, 37.8 mo-NE), respectively. Sustained MRD-negativity rates (10−5) in the ITT set were 40% in the cilta-cel arm vs 6% in the SoC arm (P&lt;0.0001); among 110 and 26 evaluable pts for sustained MRD, sustained MRD-negativity rates were 75% vs 50% (P=0.0159). Among the 176 pts who received cilta-cel as study tx, overall MRD negativity at 10−5 was achieved by 129 (73%) pts (89% of 145 evaluable pts). Conclusions: At 33.6-mo median follow-up in CARTITUDE-4, cilta-cel vs SoC significantly increased overall MRD-negativity rates &gt;3-fold in the ITT set, with pts achieving MRD negativity rapidly post cilta-cel. The prognostic value of MRD-negative ≥CR at mo 12 was shown, as median PFS was &gt;3 years in pts with MRD-negative ≥CR at mo 12, regardless of tx. These data further underscore the benefit of cilta-cel, which led to significant &gt;3-fold increases vs SoC in rates of MRD-negative ≥CR at any time and at mo 12, and sustained MRD negativity. Our MRD data demonstrate higher rates of deep and sustained MRD negativity achieved with cilta-cel vs SoC in tx of len-refractory MM as early as first relapse.

Introduction: ISB 1342 is a humanized CD38xCD3 bispecific T-cell engager using Ichnos proprietary Bispecific Engagement by Antibodies based on the T cell receptor (BEAT ®) platform, designed to simultaneously bind CD38 on multiple myeloma (MM) cells and CD3ε on T cells, to induce tumor killing. This mechanism of action is different from existing monospecific CD38 targeting therapies and was designed to overcome resistance to daratumumab in MM. ISB 1342 exhibits potent killing of the primary MM cells and MM cell lines with low sensitivity to daratumumab ( Pouleau B. et al. Blood 2023; 142 (3): 260-273). We report here, the updated findings from the weekly dose-escalations of intravenous (IV) and subcutaneous (SC) injections of an ongoing, single-agent phase 1 study (NCT03309111) of ISB 1342 in patients with RRMM. Methods: Adult patients with RRMM that relapsed after or were refractory to prior therapies, including a proteasome inhibitor, an immunomodulatory drug, and an anti-CD38 antibody; received ISB 1342 on a weekly (QW) schedule by IV or SC injection with a priming dose on the first day in 2 parallel dose-escalation schemas. Patients had measurable disease per the International Myeloma Working Group (IMWG) criteria (2016). Dose escalation in the QW schedule began at 0.2/0.3 mg/kg priming/treatment dose and followed a “3 + 3” design. The primary study objectives are to determine the maximum tolerated dose (MTD) and select a recommended phase 2 dose (RP2D) of ISB 1342. Secondary objectives includ evaluation of anti-myeloma activity, pharmacokinetics (PK), pharmacodynamics, and immunogenicity of ISB 1342. Results: As of July 18, 2023, based on ongoing clinical database, 39 subjects had received weekly IV infusions of ISB 1342 in 8 dose-escalation groups from 0.2/0.3 mg/kg to 4.0/16.0 mg/kg as priming/treatment dose; and 7 additional subjects had received weekly SC injections at 2.0/8.0 mg/kg. Two different formulations have been tested in SC group. Median number of cycles administered was 2. The majority were male (57%) and white (74%); 13% were Black or African American. The median age was 69 years (range, 54-76) and the median time since diagnosis was 6.6 years (range, 2.8-22.2). The median number of prior anti-myeloma lines of therapy was 6 (range 1-12). Twenty-one (67%) subjects were considered to be triple-class refractory and 18 (48%) penta-drug refractory. Forty-one (89%) subjects experienced treatment-related adverse events (TRAEs) of any grade. Most TRAEs were grade 1-2, including infusion related reactions (37%), cytokine release syndrome (CRS, 34%, all grade 1or 2), anemia (24%), neutropenia (24%), and thrombocytopenia (17%). Five subjects in SC group (71% of SC) had injection site reaction, all grade 1 or 2. Grade 3 or higher TRAEs occurring in more than 5% of subjects were infusion related reaction (no grade 4), anemia (no grade 4), neutropenia, leukopenia. No Grade 5 TRAE was observed. After QW IV infusion, ISB 1342 serum concentration peaked at the end of infusion and then showed bi-exponential decline. ISB 1342 serum exposures increased in a dose linear fashion across the tested IV infusion dose range. The limited PK data after SC injection suggest slow presentation of ISB 1342 into the systemic circulation leading to lower C max and delayed T max relative to IV. Transient increases in serum cytokines were observed within 24 hours after ISB 1342 dosing, including IFNg, TNFa, IL-2, IL-6 and IL-10. Transient increases in T-cell activation were observed by flow cytometry at 24-48 hours after ISB 1342 dosing at 1.0 / 4.0 μg/kg and above, based on increased expression of CD69 on peripheral blood CD4+ and CD8+ T-cell populations (Figure 1). Comparison of the available data from subjects treated at 2 / 8 μg/kg (Cohort 109) indicated reduced T-cell activation following SC compared to IV administration of ISB 1342. The efficacy signals observed in Cohorts 108 and 109 are consistent with the estimates of the lower boundary of the predicted efficacious dose range using a quantitative systems pharmacology (QSP) model based on preclinical data. Updated clinical data, including response rates and safety data, will be present at the meeting. Conclusions: Treatment with ISB 1342 was well tolerated at higher dose levels evaluated. Observed CRS events were moderate. No increased risk of infection has been observed . Updated safety, efficacy, biomarker and PK data will be presented.

AbstractDeeper responses are associated with longer survival in multiple myeloma (MM); however, limited data exist on the impact of response kinetics on outcomes. We investigated progression‐free survival (PFS) and duration of response (DOR) by response depth and in early (best confirmed response 0–4 months; n = 424) versus late responders (best confirmed response >4 months; n = 281). Newly diagnosed patients enrolled in TOURMALINE‐MM2 receiving ixazomib‐lenalidomide‐dexamethasone (IRd) (n = 351) or placebo‐Rd (n = 354) were evaluated post hoc. Deeper responses were associated with longer PFS (complete response [CR] not reached [NR], very good partial response [VGPR] 37.2 months, partial response [PR] 16.4 months) and DOR (CR NR, VGPR 42.6 months, PR 15.4 months). Among patients with a PFS (n = 511) or DOR (n = 484) of ≥6 months who achieved ≥PR, median PFS was prolonged among late versus early responders receiving IRd (59.7 vs. 17.9 months) or placebo‐Rd (56.6 vs. 12.4 months), as was median DOR (IRd, NR vs. 20.9 months; placebo‐Rd, 58.2 vs. 11.7 months). While the treatment paradigm for newly diagnosed MM is treatment to progression, our findings suggest slowness of response to a proteasome inhibitor‐immunomodulatory drug‐steroid combination is not a negative predictor of outcome.

Abstract Introduction: Depth of response is associated with long-term outcomes in multiple myeloma (MM); however, the effect of response kinetics on outcomes in NDMM is variable and less clear. Although some studies have shown that achieving a ≥very good partial response (VGPR) at 4 months (mos) from diagnosis is associated with increased overall survival (Garderet Leukemia 2018), other reports have shown worse outcomes in pts with early vs late responses (Yan Blood Adv 2019). The double-blind, randomized TOURMALINE-MM2 (NCT01850524) trial (Facon Blood 2021) showed a clinical meaningful progression-free survival (PFS) benefit with IRd vs pbo-Rd (median 35.3 vs 21.8 mos; hazard ratio, 0.830; 95% confidence interval, 0.676-1.018; P=0.073; median follow-up, 53.3 and 55.8 mos, respectively) in NDMM pts. Safety data were consistent with the established toxicity profile of IRd. We evaluated PFS and duration of response (DOR) by depth of best confirmed response and time to best response in TOURMALINE-MM2. Methods: Pts were randomized to receive oral ixazomib 4 mg (n=351) or placebo (n=354) on days 1, 8, and 15, plus oral lenalidomide 25 mg (10 mg if creatinine clearance ≤60 mL/min) on days 1-21 and oral dexamethasone 40 mg (20 mg in pts aged &gt;75 years) on days 1, 8, 15, and 22 in 28-day cycles. After 18 cycles, treatment was continued without dexamethasone and reduced doses of ixazomib (3 mg) and lenalidomide (10 mg) until progressive disease (PD)/toxicity. Response assessments were performed every cycle until PD, or every 4 weeks in pts who discontinued treatment prior to PD. PFS and DOR were analyzed post-hoc in subgroups defined by depth of response and in subgroups defined by time to best confirmed response; 'early' and 'late' responses were defined by time to best confirmed response of 0-4 and &gt;4 mos, respectively (additional analyses were performed by time to best confirmed response of 0-6 and &gt;6 mos). Pts in either subgroup could have recorded an initial response prior to their best response. PFS and DOR were evaluated from randomization to progression and time of initial response to progression, respectively. To address potential guarantee-time bias in the PFS analysis, and to eliminate potential bias due to transient responses in DOR analysis, sensitivity analyses were conducted in pts with PFS / DOR of ≥6 mos. Results: Among the 705 pts in the intention-to-treat (ITT) population, 20% (26% IRd vs 14% placebo-Rd) had a best confirmed response of complete response (CR) or stringent CR, 35% (37 vs 34%) had VGPR, 26% (19 vs 32%) had PR, 10% (9 vs 10%) had stable disease (SD), 3% (1 vs 4%) had PD. 7% (8 vs 6%) of pts were not evaluable. In a pooled analysis of both arms, achieving a deeper response was associated with longer PFS (Figure, A) and DOR (median not reached [NR], 42.8, and 15.0 mos for pts with ≥CR, VGPR, and PR, respectively). In 570 pts with ≥PR (288 IRd; 282 pbo-Rd), 152 (53%) and 136 (47%) in the IRd arm and 143 (51%) and 139 (49%) pts in the pbo-Rd arm were defined as early (0-4 mos) and late (&gt;4 mos) responders, respectively. For early vs late responders, 46% vs 40% were aged ≥75 years, 21% vs 12% had International Staging System stage III MM, and 44% vs 33% had expanded high-risk cytogenetic abnormalities. Median PFS was prolonged among late vs early responders with IRd (65.7 vs 21.2 mos) and pbo-Rd (62.6 vs 18.2 mos), as was median DOR (IRd, NR vs 22.6 mos; pbo-Rd, 64.1 vs 17.2 mos). The PFS sensitivity analysis among pts with PFS of ≥6 mos confirmed the association of late response with improved outcomes; among late vs early responders achieving ≥PR, median PFS was 65.7 vs 23.9 mos with IRd and 62.6 vs 18.4 mos with pbo-Rd (Figure, B), and among late vs early responders achieving ≥VGPR, median PFS was 65.7 vs 35.3 mos with IRd and 64.4 vs 21.7 with pbo-Rd. Conclusions: Achieving a deeper response was associated with prolonged PFS and DOR in NDMM patients in TOURMALINE-MM2. PFS benefit on the ITT analysis was driven by the higher rates of deep responses (≥VGPR) with IRd vs pbo-Rd. PFS and DOR were also longer in pts achieving a late vs early best confirmed response of ≥PR or ≥VGPR. Consistent with results from a similar analysis in relapsed/refractory MM in the TOURMALINE-MM1 trial (Garderet Leukemia 2018), our findings support the continuation of therapy with the aim of achieving a deeper response over time. Additional sensitivity analyses will be presented. Figure 1 Figure 1. Disclosures Richardson: Sanofi: Consultancy; AstraZeneca: Consultancy; Celgene/BMS: Consultancy, Research Funding; GlaxoSmithKline: Consultancy; Regeneron: Consultancy; Oncopeptides: Consultancy, Research Funding; Protocol Intelligence: Consultancy; Secura Bio: Consultancy; Janssen: Consultancy; Takeda: Consultancy, Research Funding; AbbVie: Consultancy; Karyopharm: Consultancy, Research Funding; Jazz Pharmaceuticals: Consultancy, Research Funding. Venner: Takeda: Honoraria; BMS: Honoraria; Janssen: Honoraria; Pfizer: Honoraria; Sanofi: Honoraria; GSK: Honoraria. Bahlis: GlaxoSmithKline: Consultancy, Honoraria; Janssen: Consultancy, Honoraria; Takeda: Consultancy, Honoraria; Karyopharm: Consultancy, Honoraria; BMS/Celgene: Consultancy, Honoraria; Amgen: Consultancy, Honoraria; Abbvie: Consultancy, Honoraria; Genentech: Consultancy; Sanofi: Consultancy, Honoraria; Pfizer: Consultancy, Honoraria. White: Amgen: Consultancy, Honoraria; Antengene: Consultancy, Honoraria; BMS: Consultancy, Honoraria; Forus: Consultancy, Honoraria; Sanofi: Consultancy, Honoraria; GSK: Consultancy, Honoraria; Janssen: Consultancy, Honoraria; Takeda: Consultancy, Honoraria; Karyopharm: Consultancy, Honoraria. Karlin: Celgene-BMS: Honoraria, Other: member of advisory board; Sanofi: Honoraria; oncopeptide: Honoraria; Janssen: Honoraria, Other: member of advisory board, travel support; Abbvie: Honoraria; GSK: Honoraria, Other: member of advisory board; Amgen: Honoraria, Other: travel support and advisory board ; Takeda: Honoraria, Other: member of advisory board. Rigaudeau: Takeda: Membership on an entity's Board of Directors or advisory committees. Suzuki: Bristol-Myers Squibb: Honoraria, Research Funding; Celgene: Consultancy, Honoraria, Research Funding; Amgen: Consultancy, Honoraria, Research Funding; Takeda: Consultancy, Honoraria; ONO: Honoraria; Novartis: Honoraria; Sanofi: Honoraria; Abie: Honoraria; Janssen: Consultancy, Honoraria. Shibayama: Mundi Pharma: Honoraria; Otsuka: Honoraria; Pfizer: Honoraria; Bristol-Myers Squibb: Honoraria; Sanofi: Honoraria; Nippon Shinyaku: Honoraria; Fujimoto: Honoraria; Daiichi Sankyo: Honoraria; AstraZeneca: Honoraria, Membership on an entity's Board of Directors or advisory committees; Essentia Pharma Japan: Research Funding; Chugai: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Honoraria, Research Funding; Novartis: Honoraria, Research Funding; Eisai: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Avvie: Honoraria, Research Funding; Takeda: Honoraria, Research Funding; Ono: Honoraria, Research Funding; Celgene: Research Funding. Zhang: Takeda: Current Employment. Kumar: Takeda: Current Employment, Current holder of stock options in a privately-held company. Twumasi-Ankrah: Takeda: Current Employment. Labotka: Takeda: Current Employment. Rifkin: Takeda: Membership on an entity's Board of Directors or advisory committees; Sanofi: Membership on an entity's Board of Directors or advisory committees; Fresenius-Kabi: Membership on an entity's Board of Directors or advisory committees; Coherus: Membership on an entity's Board of Directors or advisory committees; McKesson: Current Employment, Current equity holder in publicly-traded company; Karyopharm: Membership on an entity's Board of Directors or advisory committees; Bristol Myers Squibb (Celgene): Membership on an entity's Board of Directors or advisory committees; Amgen: Membership on an entity's Board of Directors or advisory committees. Lonial: AMGEN: Consultancy, Honoraria; TG Therapeutics: Membership on an entity's Board of Directors or advisory committees; BMS/Celgene: Consultancy, Honoraria, Research Funding; GlaxoSmithKline: Consultancy, Honoraria, Research Funding; Abbvie: Consultancy, Honoraria; Janssen: Consultancy, Honoraria, Research Funding; Takeda: Consultancy, Honoraria, Research Funding; Merck: Honoraria. Kumar: Antengene: Consultancy, Honoraria; Carsgen: Research Funding; Astra-Zeneca: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Oncopeptides: Consultancy; Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; Bluebird Bio: Consultancy; Beigene: Consultancy; Tenebio: Research Funding; Roche-Genentech: Consultancy, Research Funding; Novartis: Research Funding; KITE: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Merck: Research Funding; Takeda: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Amgen: Consultancy, Research Funding; BMS: Consultancy, Research Funding; Abbvie: Consultancy, 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. Moreau: Amgen: Honoraria; Oncopeptides: Honoraria; Janssen: Honoraria; Celgene BMS: Honoraria; Sanofi: Honoraria; Abbvie: Honoraria. OffLabel Disclosure: Use of the oral proteasome inhibitor ixazomib in newly diagnosed multiple myeloma patients who are ineligible for transplant.

Abstract Continuous lenalidomide-dexamethasone (Rd)-based regimens are among the standards of care in transplant-ineligible newly diagnosed multiple myeloma (NDMM) patients. The oral proteasome inhibitor ixazomib is suitable for continuous dosing, with predictable, manageable toxicities. In the double-blind, placebo-controlled TOURMALINE-MM2 trial, transplant-ineligible NDMM patients were randomized to ixazomib 4 mg (n = 351) or placebo (n = 354) plus Rd. After 18 cycles, dexamethasone was discontinued and treatment was continued using reduced-dose ixazomib (3 mg) and lenalidomide (10 mg) until progression/toxicity. The primary endpoint was progression-free survival (PFS). Median PFS was 35.3 vs 21.8 months with ixazomib-Rd vs placebo-Rd, respectively (hazard ratio [HR], 0.830; 95% confidence interval, 0.676-1.018; P = .073; median follow-up, 53.3 and 55.8 months). Complete (26% vs 14%; odds ratio [OR], 2.10; P &lt; .001) and ≥ very good partial response (63% vs 48%; OR, 1.87; P &lt; .001) rates were higher with ixazomib-Rd vs placebo-Rd. In a prespecified high-risk cytogenetics subgroup, median PFS was 23.8 vs 18.0 months (HR, 0.690; P = .019). Overall, treatment-emergent adverse events (TEAEs) were mostly grade 1/2. With ixazomib-Rd vs placebo-Rd, 88% vs 81% of patients experienced grade ≥3 TEAEs, 66% vs 62% serious TEAEs, and 35% vs 27% TEAEs resulting in regimen discontinuation; 8% vs 6% died on study. Addition of ixazomib to Rd was tolerable with no new safety signals and led to a clinically meaningful PFS benefit of 13.5 months. Ixazomib-Rd is a feasible option for certain patients who can benefit from an all-oral triplet combination. This trial was registered at www.clinicaltrials.gov as #NCT01850524.