Belantamab mafodotin-blmf, an anti–B-cell maturation antigen (BCMA) antibody-drug conjugate therapy, received accelerated approval for the treatment of adults with relapsed or refractory multiple myeloma (MM) who have received at least 4 prior therapies, including an anti-CD38 monoclonal antibody, a proteasome inhibitor, and an immunomodulatory agent.
The FDA's decision was supported by the open-label, multicenter, phase II DREAMM-2 trial, which enrolled 221 adults with relapsed/refractory MM whose disease had worsened despite receiving standard of care. Patients received IV belantamab mafodotin-blmf, dosed at 2.5 mg/kg or 3.4 mg/kg once every 3 weeks until disease progression or unacceptable toxicity. The overall response rate (the study's primary endpoint) was 31% in the cohort that received 2.5 mg/kg, which is the approved dosage. The median duration of response (DoR) was not reached at the 6-month cutoff for analysis, but 73% of patients who achieved a response to treatment had a DoR of at least 6 months.
The treatment label carries a boxed warning for 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. Ocular AEs occurred in 77% of patients in the pooled safety population. The most common AEs associated with belantamab mafodotin-blmf (occurring in >20% of patients) were keratopathy, decreased visual acuity, nausea, blurred vision, pyrexia, infusion-related reactions, and fatigue. Grades 3 and 4 keratopathy occurred in 45% and 0.5% of patients, respectively.
Sources: FDA press release, August 6, 2020; GSK press release, August 6, 2020.