Blenrep Approved as First in New Class of Cancer Treatment

August 6, 2020 – The U.S. FDA has approved BlenrepTM (belantamab mafodotin-blmf), manufactured by GlaxoSmithKline, for use as a single agent to treat adults who have relapsed or refractory multiple myeloma and have received at least four prior therapies, including an anti-CD38 monoclonal antibody, a proteasome inhibitor, and an immunomodulatory agent. Blenrep is the first in a new class of drugs known as anti-BCMA (B-cell maturation antigen) monoclonal antibodies.

Multiple myeloma is one of the most common forms of blood cancer in the United States. An estimated 32,000 people in the U.S. will be diagnosed with the disease in 2020, while approximately 13,000 will die from it. It is common for multiple myeloma to relapse or to become resistant to treatment (refractory). Blenrep targets a protein known as BCMA that is expressed by multiple myeloma cells and delivers a cytotoxic agent to the cancer cells to destroy them.

In a clinical study, Blenrep delivered a clinically meaningful overall response rate of 31% in patients who had received a median of seven prior lines of treatment. The median duration of response (DoR) had not been reached at the six-month analysis, although 73% of patients who responded to treatment experienced a DoR of at least six months.

Recommended dosing is 2.5mg/kg of body weight administered via intravenous infusion over the course of approximately 30 minutes once every three weeks until disease progression or unacceptable toxicity occur.

A black box warning cautions that there is a risk of ocular toxicity associated with the use of Blenrep. Ocular adverse reactions occurred in 77% of patients in a safety analysis. Patients should use preservative-free lubricant eye drops and avoid contact lenses unless directed by an ophthalmologist while on the medication. Blenrep caused changes in the corneal epithelium that resulted in problems such as severe vision loss and corneal ulcers, and symptoms that included blurred vision and dry eyes. Patients should receive an ophthalmic exam to establish a baseline prior to treatment and continue to receive ophthalmic exams prior to each dose, as well as promptly for worsening symptoms. Due the risk of ocular toxicity, Blenrep is available only through a Risk Evaluation and Mitigation Strategy (REMS) program.

The FDA granted accelerated approval for Blenrep based on patient response rate. Continued approval may be contingent upon verification and description of clinical benefit in confirmatory trials.

Blenrep is available at a wholesale acquisition cost (WAC) of $8,277 per vial.