The U.S. Food and Drug Administration (FDA) has granted accelerated approval to Blenrep (belantamab mafodotin-blmf), a first-in-class treatment for heavily pretreated adults with relapsed or refractory multiple myeloma, its developer, GlaxoSmithKline, announced.
The approval is specific for people who have been given at least four previous therapies, including a CD38 inhibitor, a proteasome inhibitor, and an immunomodulatory treatment. It follows last month’s recommendation from the FDA’s Oncologic Drugs Advisory Committee.
Accelerated approval is a form of conditional approval given to a medication that addresses an unmet need in a serious medical condition, providing it has shown benefits on surrogate or interim measures in a clinical trial. A confirmatory study will be needed for full approval to be given.
“The approval of Blenrep is an important advancement for patients with relapsed or refractory multiple myeloma, as it brings a much-needed new treatment to patients who face limited options due to their progressing disease,” Paul Giusti, president and CEO of the Multiple Myeloma Research Foundation, said in the press release.
Blenrep belongs to the class of antibody-drug conjugates, therapies that are essentially composed of a monoclonal antibody that is linked to a toxic drug. The antibody in Blenrep is specific to B-cell maturation antigen (BCMA), a protein found on the surface of myeloma cells, and is attached to auristatin F, a highly toxic compound not used alone. Once the antibody binds to BCMA, the toxin is released into the cancer cell, killing it.
While many therapies targeting BCMA are in development for myeloma, Blenrep is the first anti-BCMA therapy approved anywhere in the world.
“While treatable, refractory multiple myeloma is a significant clinical challenge with poor outcomes for patients whose disease has become resistant to the current standard of care. … these patients are often retreated with drugs from the same classes after they relapse, which is why the approval of Blenrep, the first anti-BCMA therapy, is significant for both patients and physicians alike,” said Sagar Lonial, MD, a professor at Emory University School of Medicine.
The ongoing trial is evaluating the safety and efficacy of two doses of Blenrep (2.5 mg/kg or 3.4 mg/kg), given every three weeks as an intravenous infusion to 196 people with myeloma who have gone through at least three prior treatment lines. Among this group, the median was seven previous treatment lines, with some patients treated up to 21 times.
Blenrep monotherapy, at its now recommended dose of 2.5 mg/kg, showed a clinically meaningful overall response rate in about one-third (31%) of patients, the FDA reported in its release, with 73% of responders having a response duration of at least six months.
Six-month study data showed that about a fifth of responses to treatment were deemed “very good” or better.
The most commonly reported adverse events in DREAMM-2, affecting at least one-fifth of participants, were keratopathy (a type of damage to the eye’s cornea), decreased visual acuity, nausea, blurred vision, fever, infusion-related reactions, and fatigue.
About three-quarters (77%) of trial participants experienced eye-related side effects, managed with regular eye exams before doses and eye drops.
Blenrep is available through the Blenrep Risk Evaluation and Mitigation Strategy (REMS), a program that requires patients and their prescribing doctors be aware of the risks associated with this treatment and appropriate monitoring. Additional information about the program can be found at here, or by calling 1-855-209-9188.
The FDA’s label comes with a boxed warning of changes in vision, and recommends ophthalmic exams at the start of treatment and prior to each dose.
“Blenrep is the first approved anti-BCMA therapy and has the potential to transform the treatment of patients with relapsed or refractory myeloma who have limited treatment options today,” Hal Barron, chief scientific officer and president of research and development at GlaxoSmithKline, said in the company’s release.