On Aug. 14, 2023, the U.S. Food and Drug Administration (FDA) granted Pfizer an Accelerated Approval for Elrexfio^™ (elranatamab-bcmm). It is a bispecific B-cell maturation antigen (BCMA)-a directed cluster of differentiation 3 (CD3) T-cell engager indicated for the treatment of adults with relapsed or refractory multiple myeloma who have received at least four prior lines of therapy including a proteasome inhibitor, an immunomodulatory agent, and an anti-CD38 monoclonal antibody. Injections of Elrexfio are given subcutaneously (SC) in a healthcare facility staffed and equipped to handle any severe side effects that may occur. The first two doses ramp up over the first week of treatment and then dosing shifts to 76mg once a week through week 24. Patients who respond to treatment receive injections once every two weeks thereafter. During the escalation period, patients should be hospitalized for 48 hours after the first dose and 24 hours after the second dose. Because Elrexfio has the potential to cause severe side effects that include cytokine release syndrome (CRS) and neurologic toxicities, it has a boxed warning and a risk evaluation and mitigation strategy (REMS). Pfizer plans to launch Elrexfio within the coming weeks. It will cost approximately $41,500 per month. Here is the full prescribing information.

At a Glance

• Brand (Generic) Name: Elrexfio (elranatamab-bcmm)
• Manufacturer: Pfizer
• Date Approved: Aug. 14, 2023
• Indication: to treat adults who have relapsed or refractory multiple myeloma that has been treated with at least four prior therapies including a proteasome inhibitor, an immunomodulatory agent, and an anti-CD38 monoclonal antibody
• Dosage Forms Available: single-dose vials containing either 76mg/1.9mL or 44mg/1.1mL
• Launch Date: Within a few weeks
• Estimated Annual Cost: $405,000 for the first year of therapy
• Multiple myeloma is a progressive, incurable blood cancer that affects plasma cells. A type of white blood cell found in bone marrow, plasma cells are matured B cells that produce antibodies. When damaged, they rapidly displace normal cells and create tumors in the bone marrow.
• The American Cancer Society (ACS) estimates that about 36,000 new cases of multiple myeloma are diagnosed annually in the U.S. Men are somewhat more likely to have it than women. At about 14%, the risk for African Americans is nearly twice as high as for members of other ethnic groups.
• Elrexfio will be used following treatment failure from four or more previous drug treatments that include a proteasome inhibitor, such as bortezomib; an immunomodulatory agent, such as Revlimid^® (lenalidomide); and an anti-CD38 monoclonal antibody, such as Darzalex^® (daratumumab).
• Approval was based on a phase II study that showed that 58% of patients responded to Elrexfio as their first BCMA-directed therapy, with approximately 82% of those patients maintaining a response for at least nine months. Among patients who had previously received a BCMA-directed therapy, the overall response rate was 33%, with approximately 84% maintaining a response for at least nine months.
• Due to instances of cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS) among study participants, Elrexfio has boxed warnings on its labeling and a risk evaluation and mitigation strategy (REMS). Other serious side effects may include blood abnormalities, life-threatening infections, liver damage, and embryo-fetal toxicity.
• The numerous other drugs available to treat multiple myeloma include several chemotherapy (chemo) regimens and some targeted therapies. High doses of chemo followed by stem cell transplants also are used for patients who can tolerate them. Resistance eventually develops to most pharmaceutical therapies, however; and many patients suffer relapses.
• Janssen’s Talvey^™ (talquetamab-tgvs) is a bispecific G protein-coupled receptor class C group 5 member D (GPRC5D)-directed CD3 T-cell engager that was approved for the same indication as Elrexfio on Aug. 9, 2023.
• Tecvayli^® (teclistamab-cqyv), a bispecific BCMA antibody and CD3 T-cell engager; and two BCMA-directed CAR-T cell therapies, Abecma^® (idecabtagene vicleucel) and Carvykti^™ (ciltacabtagene autoleucel) are also approved as a late-line treatment for multiple myeloma.
• Designated as an Orphan Drug, Elrexfio is also a Breakthrough Therapy approved under Priority Review.
• Since Accelerated Approval for Elrexfio is based on results from a phase II clinical study, additional positive results from more advanced trials will be needed before full FDA approval is granted.