Eli Lilly and Co (NYSE:LLY) shares sank after it emerged that the US Food and Drug Administration (FDA) said needed to see more data on the company’s application to accelerate approval of its potential Alzheimer’s disease treatment.
In the complete response letter to the company's accelerated approval application, the regulator specifically requested that Eli Lilly provide data from at least 100 patients who received a minimum of 12 months of continued treatment on donanemab, the company said after markets closed on Thursday.
The potential treatment using donanemab aims to clear a plaque from a person’s brain - a key hallmark of Alzheimer's, the most common form of dementia.
Eli Lilly said: "While the trial included more than 100 patients treated with donanemab, due to the speed of plaque reduction, many patients were able to stop dosing as early as six months of treatment, resulting in fewer than 100 patients receiving 12 months of donanemab."
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The confirmatory Phase 3 TRAILBLAZER-ALZ 2 trial remains ongoing, with topline data read-out expected in Q2 2023, and will form the basis of donanemab's application for traditional approval, Eli Lilly said.
"Lilly will continue to work with the FDA to evaluate the fastest pathway to make this potential treatment option widely available to patients," it noted.
The FDA’s accelerated approval program allows drugs to launch in the US based on promising early results before they’re a confirmed benefit to patients.
It recently granted accelerated approval earlier this month to another Alzheimer’s drug, Leqembi from Japan’s Eisai, which is partnered with Biogen.
Biogen and Eisai also hope to convert their accelerated approval of the drug to a traditional FDA approval, based on an already complete Phase 3 study.
Eli Lilly shares in New York dropped 2.59% at US$342 while Biogen shares added 1.19% to US$283.47.
Contact the writer at giles@proactiveinvestors.com