Second BiTE Approved for Multiple Myeloma  

Certain patients with advanced multiple myeloma may be eligible for treatment with a new immunotherapy drug. 

The U.S. Food and Drug Administration (FDA) has granted accelerated approval to talquetamab-tgvs (Talvey) for patients with multiple myeloma that did not respond to or relapsed after at least four prior lines of treatment, including an immune-modulating therapy and certain targeted therapies. 

Talquetamab-tgvs is a type of immunotherapy known as a bispecific T-cell engager (BiTE), which is an antibody that simultaneously binds proteins on cancer cells and cancer-killing T cells to bring the two cell types in proximity to one another. Talquetamab-tgvs binds the CD3 protein on T cells and the GPRC5D cell surface protein on multiple myeloma cells. Talquetamab-tgvs is the second BiTE to be approved for patients with multiple myeloma, following the accelerated approval of teclistamab-cqyv (Tecvayli) in 2022. 

T cell attacking cancer cell
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The approval of talquetamab-tgvs was based on results from MMY1001, a single-arm, open-label, multicenter phase II trial that evaluated drug efficacy in 187 patients with multiple myeloma who had received at least four prior systemic therapies, including an immune-modulating drug, a proteasome inhibitor (a drug that kills cells by blocking their ability to destroy unwanted proteins), and a monoclonal antibody against the CD38 protein that is highly expressed on multiple myeloma cells. 

Among 100 patients who received a lower dose of talquetamab-tgvs weekly, 73% experienced an objective response with a median duration of response of 9.5 months. Of the 87 patients who received a higher dose of the drug biweekly, 73.6% had responses to the therapy, and responses persisted for at least nine months in most patients. 

The prescribing information for talquetamab-tgvs includes a boxed warning indicating that the therapy may lead to life-threatening or fatal cases of cytokine release syndrome (CRS) and neurologic toxicities, including immune effector cell-associated neurotoxicity syndrome (ICANS). 

Multiple myeloma is a type of blood cancer characterized by the abnormal growth of plasma cells, a type of blood cell derived from B lymphocytes that are responsible for producing antibodies. According to federal statistics, it was estimated that 35,730 individuals would be diagnosed with multiple myeloma and 12,590 patients would die of the disease in the U.S. in 2023. 

The FDA rendered its decision on August 9, 2023. Accelerated approval means that continued approval may be contingent upon a confirmatory trial.