FDA Approves GSK’s Blenrep for the Treatment of Relapsed or Refractory Multiple Myeloma

Rare Daily Staff

The U.S. Food and Drug Administration approved GlaxoSmithKline’s Blenrep as a monotherapy treatment for adult patients with the rare blood cancer relapsed or refractory multiple myeloma.

The approval of Blenrep is for patients who have received at least four prior therapies including an anti-CD38 monoclonal antibody, a proteasome inhibitor, and an immunomodulatory agent. The indication is approved under accelerated approval based on response rate. Continued approval for this indication may be contingent upon verification and description of clinical benefit in confirmatory trials.

Multiple myeloma is the second most common blood cancer in the United States and is generally considered treatable, but not curable. In the U.S., more than 32,000 people are estimated to be diagnosed with multiple myeloma this year and nearly 13,000 people will die from the disease. 

Blenrep is an antibody drug conjugate comprising a humanized anti-B cell maturation antigen (BCMA) monoclonal antibody conjugated to the cytotoxic agent auristatin F via non-cleavable linker. Blenrep is the first anti-BCMA therapy approved anywhere in the world. The normal function of BCMA is to promote plasma cell survival. BCMA expression is limited to B cells at later stages of development. BCMA is expressed at varying levels in myeloma patients and BCMA membrane expression is universally detected in myeloma cell lines.

“Multiple myeloma is an incurable and devastating disease,” said Hal Barron, chief scientific officer and president R&D for GSK. “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.’’

Blenrep is GSK’s fifth major medicine approval in 2020 across areas of significant unmet medical need such as cancer, HIV and chronic kidney disease. This approval marks the second FDA approval for GSK’s oncology portfolio in four months.

The approval of BLENREP was based on six-month primary results from the pivotal DREAMM-2 study, which enrolled patients with relapsed or refractory multiple myeloma who had actively progressing disease that had worsened despite current standard of care.  

In the DREAMM-2 study, treatment with single-agent BLENREP 2.5 mg/kg every three weeks demonstrated a clinically meaningful overall response rate of 31 percent

in patients who had received a median of seven prior lines of treatment. The median duration of response had not been reached at the six-month analysis, but 73 percent of responders had a duration of response equal to or greater than six months. The most reported adverse events (≥20 percent) were keratopathy, decreased visual acuity, nausea, blurred vision, pyrexia, infusion-related reactions, and fatigue. Keratopathy is characterized as changes in the corneal epithelium as seen on eye examination, which can manifest with or without symptoms.

Ocular adverse reactions occurred in 77 percent of the 218 patients in the pooled safety population and included keratopathy (76 percent), changes in visual acuity (55 percent), blurred vision (27 percent) and dry eye (19 percent). Corneal adverse events were monitored with eye exams prior to each dose, allowing for dose reductions or interruptions as appropriate. Patients also used preservative-free eye drops. Keratopathy leading to treatment discontinuation affected 2.1 percent of patients in the 2.5 mg/kg cohort.

Blenrep is available through participation in the Blenrep Risk Evaluation and Mitigation Strategy, which was developed to ensure appropriate use of the medicine. The program requires education for all physicians prescribing Blenrep and their patients regarding the ocular risks associated with treatment as well as monitoring.

In 2017, Blenrep was granted Breakthrough Therapy designation by the FDA, which is intended to facilitate the development of investigational medicines that have shown clinical promise for conditions where there is significant unmet need.

Photo: Hal Barron, chief scientific officer and president R&D for GSK