On August 5, 2020, the FDA accelerated the approval of Blenrep (belantamab mafodotin-blmf; from 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 at least 4 previous therapies, including an anti-CD38 monoclonal antibody, a proteasome inhibitor, and an immunomodulatory agent.
Blenrep is the first BCMA-directed therapy approved by the FDA for patients with multiple myeloma.
The FDA approved Blenrep for intravenous infusion based on results from the DREAMM-2 clinical trial that compared 2 different dosages of this drug. Patients received either 2.5 mg/kg of Blenrep, intravenously, or 3.4 mg/kg, intravenously, once every 3 weeks until their disease progressed, or until they had unacceptable side effects.
The determination of the benefit of Blenrep was based on the overall response rate to the treatment and the length of response, as determined by an independent review committee.
The overall response rate to Blenrep therapy was 31% among those patients who received the dose of 2.5 mg/kg, meaning that almost one-third of the patients had a positive response to therapy. Of those who had a response to therapy, the majority (73%) had a response that lasted 6 months or more. Because these results were observed in patients who received the dose of 2.5 mg/kg, this is now the recommended dose of Blenrep.
The prescribing information of Blenrep includes a boxed warning alerting doctors that Blenrep can cause changes in vision resulting from damage to the cornea, and these can lead to severe vision loss and corneal ulcer, as well as symptoms of blurred vision and dry eyes. Therefore, before each dose, patients should have their eyes checked, as well as when any symptoms are developed while using Blenrep.
Because of the risk of vision-related side effects, this medication can only be prescribed through a program called Risk Evaluation and Mitigation Strategy (or REMS), to ensure that proper precautions are taken when prescribing Blenrep.
In addition to these visual side effects, other side effects reported with Blenrep were nausea, fever, fatigue, and infusion-related reactions.