Posted: Tuesday, December 20, 2022
The MagnetisMM-3 study, conducted by Nizar Jacques Bahlis, MD, of Arnie Charbonneau Cancer Institute, University of Calgary, Alberta, Canada, and colleagues evaluated the safety and efficacy of elranatamab—a humanized bispecific antibody—in patients with relapsed or refractory multiple myeloma. Presented during the 2022 American Society of Hematology (ASH) Annual Meeting and Exposition (Abstract 159), the results from Cohort A suggest this agent may not only be effective, but also demonstrates a manageable safety profile.
The investigators focused on 123 patients with multiple myeloma who had not received any B-cell maturation antigen–targeted treatments and were refractory to at least one immunomodulatory drug, proteasome inhibitor, and anti-CD38 antibody. Participants were administered subcutaneous elranatamab at 76 mg weekly on a 28-day cycle, with most receiving a two-step priming regimen (n = 119).
The median number of prior therapy lines was five, with 96.7% and 42.3% of patients being triple-class– and penta-drug–refractory, respectively. At the median follow-up of 6.8 months, 51.2% of patients were still being treated with elranatamab; the median treatment duration was 5.3 months. The objective response rate was 61%, with a median time to response of 1.2 months. Of note, progressive disease (32.5%) and adverse events (7.3%) were the most common reasons for treatment discontinuation.
Although treatment-emergent adverse events were reported in all patients, 74.8% of participants experienced events of grade 3 or 4. Infections (61.8%) were the most commonly reported adverse event, followed by peripheral neuropathy, paresthesia, and gait disturbance. With treatment-emergent adverse events responsible for 13.8% of deaths, none appeared to be related to elranatamab. Of those who received the priming regimen, cytokine-release syndrome and immune effector cell–associated neurotoxicity syndrome were reported in 56.3% and 3.4% of patients, respectively.
Disclosure: For full disclosures of the study authors, visit ash.confex.com.