Lower response rates to cevostamab in triple-class refractory multiple myeloma patients who previously received a bispecific antibody

Cevostamab is a bispecific antibody directed against FcRH5 and CD3. In the phase I/II CAMMA study, this agent proved to be highly active in a cohort of triple-class refractory multiple myeloma patients who received prior anti-BCMA therapy. During ASH 2024, Prof Michel Delforge, haematologist at the University Hospitals Leuven (Belgium) presented updated results of this trial with a specific focus on the impact of the type of prior BCMA-directed therapies. These updated results confirmed the manageable safety profile of cevostamab in this setting. Furthermore, a lower response rate was observed among patients who previously received a BCMA-targeted bispecific antibody compared to patients in whom the prior anti-BCMA treatment consisted of an antibody-drug conjugate (ADC) or CAR-T cell therapy. A possible explanation for this lower response rate can be found in the fact that patients who previously received an anti-BCMA bispecific antibody had lower levels of soluble BCMA at baseline than patients in the prior ADC or prior CAR-T group.