MagnetisMM-1: Data Updates of Anti-BCMA Bispecifics in MM
Expert perspectives from Joselle Cook, MBBS, on use of elranatamab in relapsed/refractory multiple myeloma based on data from the MagnetisMM-1 trial.
Transcript:
Rafael Fonseca, MD: I'll go next to Dr Cook. Dr Cook, I wonder if you could provide us with an update from the MagnetisMM-1 clinical trial of elranatamab.
Joselle Cook, MBBS: Certainly. The updated results of the MagnetisMM-1 trial were presented to us at ASH [American Society of Hematology] December of 2022 by Dr Raje, and she presented elranatamab, which targets BCMA [B-cell maturation antigen] as well as CD3 on T cells. And so, this is a different BCMA bispecific that's not yet in clinical practice, but we certainly look forward to seeing how we use this when it does eventually get approved. In this trial, 55 patients received elranatamab monotherapy at different doses from 215 to 1000 mcg/kg. This was given subcutaneously either weekly or every 2 weeks. The median age of these patients was about 64 years old. But I would note that patients up to age 80 got this drug. Twenty-seven percent of these patients were either Black or Asian. So, this study really incorporated nonwhite patients. The median number of regimens that patients received before coming onto this trial was 5, although some patients received between 2 to 14. So, a heavily pretreated population was incorporated here. Ninety-one percent of these patients were triple-class refractory. About 70% had a stem cell transplant in the past, and one-third of these patients had high-risk cytogenetics. I think it's really great to see that a quarter of these patients had prior BCMA therapies. We’re getting to see how we can potentially sequence BCMA-directed therapies based on this trial. The median time to response with elranatamab was 36 days. The median follow-up was about 12 months, and at that time, the overall response rate was 64%, with 56% of these patients achieving VGPR [very good partial response] or better, and 38% of these patients achieving a CR [complete response] or better. These are really impressive responses in patients who are heavily pretreated. And then for the patients who had received prior BCMA therapy, there were 13 patients, over half of them achieved a VGPR or better. The event-free survival at a year was about 60%, and the duration of response was an impressive 17 to 18 months. I think this really speaks to the efficacy of elranatamab in patients who've been heavily pretreated and in patients who've seen prior BCMA therapies. We'll need to talk, of course, about the toxicities. The main thing would be CRS [cytokine release syndrome], which again was low grade, similar to what Shaji mentioned for teclistamab. This was limited to grade 1 and grade 2, and there were no higher CRS events reported. Other things to note would be neutropenia, anemia, injection site reactions, and lymphopenia. With this study, it was noted that with premedication and a single priming dose, that the overall incidence of CRS was reduced. So, I'm really excited to see how we're going to be using this in the future and how we're going to be sequencing this drug. But obviously, we're seeing that elranatamab is inducing durable clinical responses in all evaluable patients with confirmed CR or better. And these patients, by the way, that did get a CR all had MRD [measurable residual disease] negative responses. So, this is really impressive.
Rafael Fonseca, MD: Thank you very much, Dr Cook.
Transcript edited for clarity.
