Dr Byun on Responses to Mezigdomide and Elranatamab in Relapsed/Refractory Multiple Myeloma

“We are moving towards [a] cure of multiple myeloma, so using the best options upfront is always the best option. Because we saw such amazing results, albeit [with] a very small number of patients, we are hoping that part 2 will provide us [with] more information, and hopefully this doublet will move forward to earlier lines of therapy.”

Ja Min Byun, MD, PhD, an assistant professor in the Department of Internal Medicine at Seoul National University College of Medicine and a hematologist-oncologist at the Center for Hematological Oncology at Seoul National University Hospital, discussed why efficacy was consistent regardless of mezigdomide dose or number of prior lines of therapy in part 1 of the phase 1b/2 MELT-MM trial (NCT06645678) evaluating mezigdomide plus the BCMA x CD3 bispecific antibody elranatamab (Elrexfio) in relapsed/refractory multiple myeloma, and made the case for moving the doublet into earlier treatment lines.

Part 1 enrolled patients with at least 2 prior lines of therapy, including a proteasome inhibitor and lenalidomide (Revlimid), and an ECOG performance status up to 2, Byun said. Efficacy did not differ by mezigdomide dose or by number of prior lines, she noted: the overall response rate (ORR) was 100% at both the 0.3-mg (n = 7 of 7) and 0.6-mg (n = 6 of 6) dose levels, including among patients who were triple-class or penta-refractory.

A 100% ORR was a surprise, according to Byun, given that the 13 efficacy-evaluable patients had received a median of 4 prior lines of therapy (range, 2-7)—a heavily pretreated population in which such deep responses are uncommon, she said.

With the field moving toward a cure for multiple myeloma, Byun said using the most effective regimens as early as possible should be the goal. Given the strength of the part 1 signal despite the small cohort, she said she is hopeful the ongoing part 2 expansion will generate the additional data needed to eventually move mezigdomide plus elranatamab into earlier lines of therapy.