On August 5, 2020, the FDA accelerated the approval of belantamab mafodotin-blmf (Blenrep; GlaxoSmithKline), a B-cell maturation antigen (BCMA)-directed antibody and microtubule inhibitor conjugate, for the treatment of adults with relapsed or refractory multiple myeloma who have received ≥4 previous therapies, including an anti-CD38 monoclonal antibody, a proteasome inhibitor, and an immunomodulatory agent.
The FDA granted belantamab mafodotin an orphan drug designation and a breakthrough therapy designation for this indication.
The FDA approved belantamab mafodotin based on the DREAMM-2 study, an open-label, multicenter clinical trial. Patients received belantamab mafodotin 2.5 mg/kg or 3.4 mg/kg intravenously once every 3 weeks until disease progression or unacceptable toxicity.
The efficacy end point included overall response rate (ORR) and response duration, as evaluated by an Independent Review Committee using the International Myeloma Working Group uniform response criteria. The ORR was 31% (97.5% confidence interval, 21%-43%). Overall, 73% of those who responded to therapy with the 2.5-mg/kg dose of belantamab mafodotin had a response lasting ≥6 months.
The most common (≥20%) adverse reactions to belantamab mafodotin therapy included keratopathy, decreased visual acuity, nausea, blurred vision, pyrexia, infusion-related reactions, and fatigue.
Because belantamab mafodotin is associated with a risk for serious ocular adverse events, including changes in the corneal epithelium resulting in severe vision loss and corneal ulcer, in addition to blurred vision and dry eyes, the drug is only available through a Risk Evaluation and Mitigation Strategy (REMS), the BLENREP REMS.
The recommended dose of belantamab mafodotin is 2.5 mg/kg as an intravenous infusion over approximately 30 minutes once every 3 weeks.