A Food and Drug Administration panel on Friday unexpectedly declined to endorse Biogen's experimental Alzheimer's drug aducanumab in a setback for the pharmaceutical company.
In an 8-1 vote, the panel said Biogen's late-stage study didn't provide "strong evidence" showing that aducanumab effectively treated Alzheimer's. Two other panelists said it the data was "uncertain."
The FDA could still approve the drug, which would make it the first drug approved to slow cognitive decline in people living with the disease and the first new treatment for Alzheimer's in nearly 20 years.
Shares of Biogen were halted Friday ahead of the meeting of outside experts.
Biogen shares had surged Wednesday after FDA staff gave a positive review of the drug. In a 343-page document, the FDA said results from Biogen's late-stage trial were "highly persuasive" and the study was "capable of providing the primary contribution to a demonstration of substantial evidence of effectiveness" of aducanumab. "Based on the considerations above, the applicant has provided substantial evidence of effectiveness to support approval," the FDA added.
Alzheimer's disease is a progressive neurodegenerative disorder that slowly destroys memory and thinking skills. The Alzheimer's Association estimates more than 5 million Americans are living with the disease.
Biogen's intravenous drug targets a "sticky" compound in the brain known as beta-amyloid, which is hypothesized to play a role in the devastating disease. Biogen has previously estimated about 1.5 million people with early Alzheimer's in the U.S. could be candidates for the drug, according to Reuters.
Some Alzheimer's experts and Wall Street analysts have been skeptical about the drug's benefits, especially after Biogen reversed its decision to seek regulatory approval in 2019.
The company shocked investors in October of that year by announcing it was seeking regulatory approval after all after pulling the plug on the drug in March. Biogen scientists said at the time that a new analysis of a larger data set showed that aducanumab "reduced clinical decline in patients with early Alzheimer's disease."
There are currently no drugs cleared by the FDA that can slow or reverse the mental decline from Alzheimer's, which is the sixth leading cause of death in the United States. The U.S. agency has approved Alzheimer's drugs aimed at helping symptoms, not actually reversing or slowing the disease itself.
During the meeting on Friday with the Peripheral and Central Nervous System Drugs Advisory Committee, Dr. Billy Dunn, director of the Office of Neuroscience in the FDA's Center for Drug Evaluation and Research, said there was an "enormous unmet medical need."
"Currently approved treatments do not target the underlying pathology of Alzheimer's disease and their beneficial effects are modest," he said, adding there has not been an approval of a treatment for the disease since 2003.
In a letter sent to the FDA ahead of the meeting, the Alzheimer's Association said the publicly released data so far "justifies approval accompanied by a Phase 4 post-marketing surveillance study."
"The alternative, requiring completion of an additional Phase 3 trial, would deny broad access up to four years while it is completed. A four-year delay is too long to wait for millions of Americans facing a progressive, fatal disease. A four-year delay is too long to wait for millions of American caregivers," the organization said.
The FDA's final decision on Biogen's drug is expected by March.
This is a developing story. Please check back for updates.