Posted: Friday, June 24, 2022
Alexander M. Lesokhin MD, of Memorial Sloan Kettering Cancer Center/Weill Cornell Medical College, New York, and colleagues conducted the MagnetisMM-3 trial to assess the safety and efficacy of elranatamab—a B-cell maturation antigen (BCMA)-CD3 bispecific antibody—in patients with relapsed or refractory multiple myeloma. The initial safety results of this trial, which suggest that elranatamab with a two–step-up priming regimen is well tolerated, were presented during the 2022 American Society of Clinical Oncology (ASCO) Annual Meeting (Abstract 8006).
This phase II trial enrolled 60 patients with multiple myeloma who were refractory to at least one immunomodulatory drug, anti-CD38 antibody, and proteasome inhibitor into cohort A; those who had previous exposure to BCMA-directed antibody-drug conjugates or chimeric antigen receptor T cells were assigned to either cohort A or B, respectively. Participants received 76 mg of subcutaneous elranatamab weekly on a 28-day cycle.
The median duration of elranatamab monotherapy was 9.8 weeks, with a median relative dose intensity of 87.4%. All patients experienced treatment-emergent adverse events, 75% of which were grade 3 or 4. The most common hematologic treatment-emergent adverse events included anemia, neutropenia, and thrombocytopenia. Of note, cytokine-release syndrome and immune effector cell–associated neurotoxicity syndrome were reported in 58.9% and 3.6% of individuals, respectively.
Additionally, the most common nonhematologic treatment-emergent adverse event was fatigue; infections were found in 46.7% of patients, with upper respiratory tract infections among the most common (11.7%). Approximately 5% of participants discontinued treatment due to adverse events, and 10 deaths were attributed to disease progression (n = 8), septic shock (n = 1), and unknown causes (n = 1).
Disclosure: For full disclosures of the study authors, visit coi.asco.org.