Just when the future looked bleak for GSK’s Blenrep comeback in the U.S., the FDA has blessed the company's multiple myeloma ambitions with a glimmer of hope.
Following last week’s negative feedback from the FDA’s Oncologic Drugs Advisory Committee (ODAC), the agency was scheduled to make the final call on the drug’s use in patients with multiple myeloma who have received at least one prior line of therapy by July 23.
Now, the FDA has pushed back its decision date to Oct. 23, tacking on extra time to “review additional information provided in support of the application,” GSK announced Wednesday.
“GSK is confident in the data supporting Blenrep combinations and looks forward to ongoing constructive conversations with the FDA as they continue their review,” the company said.
The delayed decision could suggest a wavering in the FDA’s original stance on Blenrep’s benefit-risk profile. GSK's shares traded up about 3% in the wake of the announcement.
Before the ODAC vote, the regulator raised safety and dosage concerns that cropped up in clinical trials. In its July 15 briefing document, the FDA flagged “high rates of ocular toxicity" and “high rates of dose modifications” seen in GSK’s pivotal DREAMM trials. The FDA cited keratopathy and visual acuity events experienced by the majority of patients enrolled in both DREAMM-7 and DREAMM-8 and questioned whether the doses evaluated in the studies were “adequately optimized.”
Last week, the ODAC delivered a negative vote on the drug in both of its proposed combinations, with Takeda’s Velcade and dexamethasone and with Bristol Myers Squibb’s Pomalyst and dexamethasone. Blenrep when combined with Velcade elicited a 3-5 negative vote, while Blenrep paired with Pomalyst was snubbed in a 1-7 negative vote.
The advisory committee also took issue with the demographics of those enrolled in the DREAMM trials. U.S. patient enrollment was less than 5% in each study, leaving some voters opposed to Blenrep’s use in the U.S. patient population.
GSK is hoping to give Blenrep a second chance at the U.S. market after the FDA previously endorsed the drug in 2020 as a monotherapy in the fifth-line treatment of multiple myeloma. The company pulled the therapy from global markets two years later after a confirmatory trial fell short.
When it was sold in the U.S., Blenrep carried an FDA boxed warning for its ocular toxicity risks.
GSK, optimistic about a global comeback, has put the drug’s peak sales estimate at more than 3 billion pounds sterling (about $4 billion). The company hopes to displace Johnson & Johnson’s leading Darzalex in second-line multiple myeloma, Chief Commercial Officer Luke Miels noted last year on a call with reporters.
Blenrep's blockbuster potential is key to GSK's goal of generating total sales of more than 40 billion pounds sterling ($50 billion) in 2031. The company is already looking ahead of its current Blenrep positioning and is studying the drug in a trial in the first-line setting, which is expected to read out by the end of 2027.
Meanwhile, Canada decided to endorse both Blenrep combinations on Wednesday. Health Canada based the nods on the “superior efficacy results” demonstrated in the DREAMM trials, including statistically significant progression-free survival outcomes in both studies and overall survival evidence from DREAMM-7. The trials tested the Blenrep combos against standard-of-care treatment regimens.
Besides Canada, GSK's drug has already been cleared in a few other markets, including the U.K. and Japan.