In a stunning reversal, Biogen says it will ask the US Food and Drug Administration to approve its Alzheimer’s disease treatment aducanumab. In March, the biotech firm pulled the plug on Phase III studies of the antibody, which breaks up amyloid-β plaques in the brain, after an independent review board said it was unlikely to offer any meaningful benefit to people with the neurodegenerative disorder.
5.8 million: Number of people living with Alzheimer’s in the US
14 million: Number of people projected to have Alzheimer’s by 2050
$290 billion: Estimated cost of Alzheimer’s and other dementias in 2019
$1.1 trillion: Estimated cost of Alzheimer’s and other dementias by 2050
Source: Alzheimer’s Association.
The review board made its recommendation based on data from 1,748 patients who had been on the drug for 18 months. After the trials were discontinued, Biogen and its development partner, Eisai, analyzed a larger data set—3,285 patients, 2,066 of whom had received the full 18-month treatment course—and saw an improvement in a subset taking the highest dose of the drug. Biogen discussed that new trend with the FDA and now expects to file for approval in early 2020.
Investors, Alzheimer’s experts, and industry watchers alike are flabbergasted by this latest twist in the aducanumab saga. The amyloid-β section of the pharmaceutical graveyard is expansive. Everyone assumed aducanumab would lie alongside other failed amyloid-targeting small molecules and antibodies.
Experts are now scrambling to try to understand whether the clinical benefit is real. Wall Street analysts called the effect of the higher dose “inconsistent” and “marginal.” In a note to investors, J.P. Morgan analyst Cory Kasimov says, “We still have some major questions about the data and whether or not the filing will be ultimately approvable, but it’s also hard to look past the unmet medical need and the FDA simply saying there’s a chance.”
Indeed, the possibility of the first disease-modifying drug for the rapidly rising population living with Alzheimer’s is tantalizing.
“It gives hope to those currently impacted by this terrible disease, and it also appears to give us a chance to find effective prevention therapies sooner than otherwise possible,” says Eric M. Reiman, executive director of the Banner Alzheimer’s Institute. He cautions, however, that “we need to see additional data in their planned scientific presentations and a peer-reviewed article to better understand the full implications.”