The study evaluated the efficacy and safety of linvoseltamab, a B-cell maturation antigen × CD3 (BCMA×CD3) bispecific antibody, in patients with relapsed/refractory multiple myeloma (RRMM) who had progressed on or after three prior lines of therapy. The primary objective was to assess the overall response rate (ORR) of linvoseltamab. The study included 282 patients, with 117 treated at a full dose of 200 mg and 104 at 50 mg. The median duration of follow-up was 14.3 months for the 200 mg group and 7.4 months for the 50 mg group. The ORR was 70.9% for the 200 mg group and 48.1% for the 50 mg group, with a median duration of response (DOR) of 29.4 months and a median progression-free survival (PFS) not reached. The safety profile was generally manageable, with cytokine release syndrome (CRS) being the most common adverse event, occurring in 46% of patients. A response-adapted regimen allowed patients achieving a very good partial response or better to switch to once-every-4-week dosing after 24 weeks, which was associated with sustained efficacy and a decrease in infection rates. Linvoseltamab demonstrated high efficacy and a favorable safety profile, making it a promising treatment option for RRMM.The study evaluated the efficacy and safety of linvoseltamab, a B-cell maturation antigen × CD3 (BCMA×CD3) bispecific antibody, in patients with relapsed/refractory multiple myeloma (RRMM) who had progressed on or after three prior lines of therapy. The primary objective was to assess the overall response rate (ORR) of linvoseltamab. The study included 282 patients, with 117 treated at a full dose of 200 mg and 104 at 50 mg. The median duration of follow-up was 14.3 months for the 200 mg group and 7.4 months for the 50 mg group. The ORR was 70.9% for the 200 mg group and 48.1% for the 50 mg group, with a median duration of response (DOR) of 29.4 months and a median progression-free survival (PFS) not reached. The safety profile was generally manageable, with cytokine release syndrome (CRS) being the most common adverse event, occurring in 46% of patients. A response-adapted regimen allowed patients achieving a very good partial response or better to switch to once-every-4-week dosing after 24 weeks, which was associated with sustained efficacy and a decrease in infection rates. Linvoseltamab demonstrated high efficacy and a favorable safety profile, making it a promising treatment option for RRMM.