On August 5, the U.S. Food and Drug Administration (FDA) granted accelerated approval to belantamab mafodotin-blmf (Blenrep), an anti-B-cell maturation antigen antibody-drug conjugate, for adult patients with relapsed or refractory multiple myeloma who have received at least four prior therapies, including an anti-CD38 monoclonal antibody, a proteasome inhibitor, and an immunomodulatory agent.
Belantamab mafodotin-blmf was evaluated in DREAMM-2, an open-label, multicenter trial. Patients received either belantamab mafodotin-blmf at 2.5 mg/kg or 3.4 mg/kg intravenously once every 3 weeks until disease progression or unacceptable toxicity.
Efficacy was based on overall response rate and response duration, as evaluated by an independent review committee using the International Myeloma Working Group uniform response criteria. The overall response rate was 31% (97.5% confidence interval = 21%–43%). Seventy-three percent of responders had response durations lasting 6 or more months. These results were observed in patients receiving the recommended dose of 2.5 mg/kg.
The prescribing information includes a Boxed Warning stating belantamab mafodotin-blmf causes changes in the corneal epithelium resulting in alterations in vision, including severe vision loss and corneal ulcer and symptoms such as blurred vision and dry eyes. Ophthalmic exams at baseline, prior to each dose, and promptly for worsening symptoms should be conducted.
Because of the risks of ocular toxicity, belantamab mafodotin-blmf is only available through a restricted program under a Risk Evaluation and Mitigation Strategy (REMS), called the BLENREP REMS.
Adverse reactions in ≥ 20% patients who received belantamab mafodotin-blmf were keratopathy, decreased visual acuity, nausea, blurred vision, pyrexia, infusion-related reactions, and fatigue.
The recommended belantamab mafodotin-blmf dose is 2.5 mg/kg as an intravenous infusion over approximately 30 minutes once every 3 weeks.