Dr Lee on the Investigation of Linvoseltamab in Relapsed/Refractory Multiple Myeloma

Hans C. Lee, MD, associate professor, Department of Lymphoma/Myeloma, Multiple Myeloma Clinical Research, Department of Lymphoma/Myeloma, Division of Cancer Medicine, the University of Texas MD Anderson Cancer Center, discusses the investigation of the BCMA x CD3 bispecific antibody linvoseltamab (REGN5458) in patients with relapsed/refractory multiple myeloma.

At the 2023 ASCO Annual Meeting, investigators presented findings from the phase 2 LINKER-MM1 study (NCT03761108) on the use of linvoseltamab, which was explored at 2 given doses. In the 50-mg cohort (n = 104), the overall response rate (ORR) was 50%, including a stringent complete response (sCR) rate of 14% and a complete response (CR) rate of 7%. In the 200-mg cohort (n = 117), the ORR was 71%, including sCR and CR rates of 16% and 14%, respectively.

Within both treatment arms, step-up dosing was used with 5 mg of linvoseltamab given on day 1 and 25 mg given on day 8. Patients then continued with 50 mg or 200 mg from week 3 on.

Notably, the majority of patients who were included in the 200-mg cohort remained on the study at the time of data cutoff of February 2023, Lee continues. Among patients with a sCR across both the 50-mg and 200-mg cohorts who had evaluable MRD data (n = 54), 54.3% of patients were MRD-negative at a 10-5 sensitivity.

In terms of duration, responses appeared to be durable and deepened with time, Lee adds. The 6-month probability of maintaining a response in the 200-mg cohort was 83.6%, and the 12-month probability was 79.2%. In the 50-mg cohort, the median progression-free survival (PFS) was 7.9 month (95% CI, 2.1-12.9), and in the 200-mg cohort, the median PFS had not been reached. The estimated 6-month PFS rates in the 50-mg and 200-mg cohorts were 54.6% and 72.7%, respectively.