Last reviewed 2026-04-20 · How we verify

Elrexfio (Elranatamab)

Bispecific antibody binding BCMA on myeloma cells and CD3 on T-cells, causing cytolysis.

Elranatamab (Elrexfio) is a bispecific BCMA-directed T-cell engager approved under accelerated approval for relapsed or refractory multiple myeloma after ≥4 prior lines of therapy. The drug demonstrates dose-proportional pharmacokinetics with a 22-day half-life and 56.2% subcutaneous bioavailability, achieving steady-state exposure by week 48 on biweekly dosing. Primary risk involves cytokine release-mediated suppression of CYP enzymes, requiring monitoring of CYP substrate drug concentrations. Continued approval is contingent upon verification of clinical benefit in confirmatory trials.

At a glance

Mechanism of action

Elranatamab-bcmm is a bispecific B-cell maturation antigen (BCMA)-directed T-cell engaging antibody that functions as a bridge between BCMA-expressing multiple myeloma cells and CD3-expressing T-cells. By binding simultaneously to both targets, the drug brings T-cells into close proximity with myeloma cells, leading to T-cell activation and cytolysis of BCMA-expressing cells. The mechanism involves activation of T-cells and proinflammatory cytokine release, which directly results in multiple myeloma cell lysis. This dual-targeting approach leverages the body's own immune system to eliminate malignant plasma cells and plasmablasts that express BCMA. The bispecific design allows for targeted engagement of tumor cells while minimizing off-target effects, making it a precision immunotherapy approach for relapsed or refractory multiple myeloma.

Approved indications

• Relapsed or refractory multiple myeloma

Common side effects

• Neutropenia
• Cytokine release syndrome
• Anaemia
• Diarrhoea
• Fatigue
• Decreased appetite
• Thrombocytopenia
• Nausea
• Pyrexia
• Injection site reaction
• Hypokalaemia
• Headache

Drug interactions

• CYP substrates (particularly those with narrow therapeutic index)

Primary sources

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