Another Immunotherapy for Multiple Myeloma 

The FDA has approved another T-cell engager therapy for patients with heavily pretreated multiple myeloma 

The U.S. Food and Drug Administration (FDA) has granted accelerated approval to elranatamab-bcmm (Elrexfio) for the treatment of adult patients with multiple myeloma whose cancers have relapsed following or did not respond to at least four prior lines of therapy, including a proteasome inhibitor, an immune modulating drug, and an antibody targeting the receptor CD38. 

Elranatamab-bcmm is a type of immunotherapy called a bispecific T-cell engager (BiTE). It contains two antibody-like fragments—one that targets the B-cell maturation receptor (BCMA) on multiple myeloma cells, and another that targets the receptor CD3 on T cells. The BiTE brings the two cell types together to help the T cells fight the cancer cells. 

Elranatamab-bcmm is the third BiTE to be approved for multiple myeloma. Teclistamab-cqyv (Tecvayli) also targets BCMA and CD3 and was approved in October 2022. Talquetamab-tgvs (Talvey) targets the protein GPRC5D on myeloma cells and CD3 on T cells and was approved in August 2023. 

The approval was based on results from MagnetisMM-3, an open-label, single-arm, multi-center, phase II study in which 97 patients with heavily pretreated multiple myeloma were given elranatamab-bcmm. Patients had previously received at least four lines of therapy, including an immune-modulating drug, a proteasome inhibitor (which causes the toxic accumulation of unwanted proteins), and an antibody targeting the receptor CD38 that is highly expressed on multiple myeloma cells. 

The overall response rate was 57.7%. Responses lasted for at least six months in 90.4% and at least nine months in 82.3% of patients whose cancers responded. The median duration of response was not reached. 

The prescribing information for elranatamab-bcmm contains a boxed warning for cytokine release syndrome (CRS) and neurological toxicities, including immune effector cell-associated neurotoxicity syndrome (ICANS), both of which can be life-threatening or fatal. 

Multiple myeloma is a cancer that arises from immune cells called plasma cells, which are B cells that make antibodies. According to federal statistics, it was estimated that 37,730 individuals would be diagnosed with multiple myeloma and 12,580 patients would die of the disease in the U.S. in 2023. 

The FDA rendered its decision on August 14, 2023. Accelerated approval means that continued approval may be contingent upon a confirmatory trial.