BioPharma

FDA AdCom votes unanimously in favor of GSK myeloma drug, despite earlier agency skepticism

The Oncologic Drugs Advisory Committee voted 12-0 that the benefit-risk profile of belantamab mafodotin supported the drug. The vote came despite concerns expressed by the FDA in briefing documents ahead of the ODAC meeting, particularly with regard to ocular toxicity.

A panel of experts convened by the Food and Drug Administration has voted in favor of a GlaxoSmithKline drug for relapsed and refractory multiple myeloma that could become the first of a new class that has attracted significant attention from several companies.

On Tuesday, FDA’s Oncologic Drugs Advisory Committee voted 12-0 that the benefits of London-based GSK’s belantamab mafodotin – an antibody drug conjugate that targets a protein highly expressed in multiple myeloma known as BCMA – outweigh the potential risks. If it wins FDA approval, it will be the first BCMA-targeting therapy to do so. The FDA sometimes convenes advisory committees, or AdComs, when it needs outside expertise in making its approval decisions and, while not bound by AdCom votes, usually follows them in approving or rejecting drugs.

ODAC’s vote may come as a surprise, given that in a briefing document released last week, the FDA was skeptical of the drug’s risk-benefit profile, citing in particular a high rate of ocular toxicity among patients, particularly keratopathy. The briefing document noted that the drug was associated with severe vision loss in some patients and significant interference in daily living activities, as well as driving and reading. Moreover, the effects have not typically been seen in other drugs used to treat multiple myeloma, while it remained unclear how they should be mitigated, and data on reversibility and severity was incomplete, the agency stated.

Shares of GSK were up about 1.6% on the New York Stock Exchange when markets closed Tuesday and were up by less than 0.2% in after-hours trading.

“We believe that belantamab mafodotin has significant potential for patients with relapsed or refractory multiple myeloma whose disease continues to progress despite current standard-of-care treatment options,” a GSK spokesperson wrote in an emailed statement following the vote. “We are committed to working closely with the FDA to complete the review of belantamab mafodotin for these patients who have limited treatment options.”

The company sought approval for the drug based on data from the DREAMM clinical trial program, particularly the registration-directed Phase II study DREAMM-2, six-month primary results of which were published in December in The Lancet Oncology.

Several other therapies are also in development that target BCMA. These include three CAR-T cell therapies – bluebird bio and Bristol-Myers Squibb’s idecabtagene vicleucel, BMS’ orvacabtagene autoleucel and Johnson & Johnson’s JNJ-4528 – as well as bispecific antibodies like J&J’s teclistamab, as well as Amgen’s AMG 420 and AMG 701. BCMA-targeting therapies are especially seen as holding promise for patients who have exhausted the usual “backbone” myeloma drug classes like proteasome inhibitors, immunomodulators and CD38-targeting monoclonal antibodies.

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