Dr Mohty on Extended Follow-up Data from MagnetisMM-3 With Elranatamab in R/R Myeloma

Mohamad Mohty, MD, PhD, professor of Hematology and head of the Hematology and Cellular Therapy Department at Saint-Antoine Hospital and Sorbonne University in Paris, France, discusses extended follow-up from cohort A of the phase 2 MagnetisMM-3 trial (NCT04649359) of elranatamab (PF-06863135) monotherapy in patients with relapsed/refractory multiple myeloma who received at least 1 proteasome inhibitor, 1 immunomodulatory drug, and 1 anti-CD38 antibody, and were naïve to BCMA-directed therapies.

Data presented at the 2023 EHA Congress showed that among all evaluable patients in cohort A (n = 123), elranatamab elicited an overall response rate (ORR) of 61.0% (95% CI, 51.8%-69.6%), including a stringent complete response (sCR) rate of 15.4%, a complete response (CR) rate of 19.5%, a very good partial response rate (VGPR) of 21.1%, and a partial response (PR) rate of 4.9%. In patients who received 2 or 3 prior lines of therapy (n = 26), the ORR was 73.1% with sCR, CR, VGPR, and PR rates of 19.2%, 26.9%, 23.1%, and 3.8%, respectively.

Additional data showed that the ORR and CR or better rate for patients without extramedullary disease (n = 84) were 71.4% and 40.5%, respectively. Those rates were 75.0% and 53.6%, respectively, for those with Revised International Staging System stage I disease (n = 28). 

The median time to response for the overall population was 1.2 months (range, 0.9-7.4). Among evaluable patients who achieved a sCR or CR (n = 29), the minimal residual disease–negativity rate at a 10^-5 sensitivity was 89.7%. 

At a median follow-up of 14.7 months for the overall population in cohort A, the median progression-free survival (PFS) and overall survival (OS) had not yet been reached. The 15-month PFS and OS rates were 50.9% and 56.7%, respectively. The 15-month duration of response rate was 71.5%. The survival rates observed thus far are promising, if not unprecedented, for this patient population, Mohty concludes.