Evaluation of elranatamab vs EPd, PVd, or Kd in patients with relapsed or refractory multiple myeloma and prior anti-CD38–directed therapy: MagnetisMM-32.

Abstract

TPS7576 Background: Elranatamab (ELRA), a humanized B-cell maturation antigen (BCMA)-CD3 bispecific antibody, has shown efficacy and manageable safety as a monotherapy in patients with relapsed or refractory multiple myeloma (RRMM). This study will evaluate ELRA monotherapy vs elotuzumab-pomalidomide-dexamethasone (EPd), pomalidomide-bortezomib-dexamethasone (PVd), or carfilzomib-dexamethasone (Kd) in patients with RRMM to determine whether ELRA can provide superior clinical benefit. Methods: MagnetisMM-32, a phase 3, open-label, multicenter, randomized study, will enroll ≈492 patients. Patients will receive ELRA (Arm A) or investigator’s choice of EPd, PVd or Kd (Arm B), until disease progression, unacceptable toxicity, withdrawal of consent, loss to follow-up, or study termination. Patients treated with ELRA will receive 2 step-up priming doses followed by weekly doses in a 28-day cycle. Patients who achieve a PR or better for ≥2 months will be eligible for reduced dosing frequency. Patients will be randomized 1:1 (stratified by prior line of therapy [1 vs 2 vs 3/4] and International Staging System disease stage [1/2 vs 3]). Key inclusion criteria include age of ≥18 years, prior multiple myeloma diagnosis with measurable disease (per IMWG criteria), evidence of progressive disease or failure to achieve a response to last line of multiple myeloma therapy, 1 to 4 prior lines of therapy including an anti–CD38 antibody–containing regimen (for ≥2 consecutive cycles) and a lenalidomide-containing regimen (for ≥2 consecutive cycles), adequate bone marrow function, and an ECOG performance status of ≤2. Key exclusion criteria include stem cell transplant ≤12 weeks prior to enrollment; active, uncontrolled infection; prior BCMA-directed or CD3-redirecting therapy; and unable to receive EPd, PVd, or Kd. The primary and key secondary endpoints are progression-free survival (PFS) by blinded independent central review (BICR) per IMWG criteria and overall survival (OS), respectively. Other secondary endpoints include PFS by investigator, objective response rate, duration of response, time to response by BICR, PFS on next line of therapy per IMWG criteria, MRD negativity rate, safety, pharmacokinetics of ELRA, immunogenicity, and health-related quality of life outcomes. The primary endpoint and OS will be compared statistically between treatment arms by stratified log-rank tests. Clinical trial information: NCT06152575 .