Topline
The FDA has delayed a decision on whether it will approve donanemab, Eli Lilly’s closely watched new Alzheimer’s drug, despite promising study results that showed it could significantly slow cognitive and functional decline in early-symptomatic Alzheimer’s patients, the pharmaceutical company announced Friday.
FILE - A sign for Eli Lilly & Co. stands outside their corporate headquarters in Indianapolis on ... [+]
Key Facts
The FDA informed Eli Lilly it was planning to convene an advisory committee to further assess donanemab’s safety and efficacy, especially in light of the “unique trial design” of the last study, which allowed users to stop using the drug to based on the levels of “amyloid plaque”—the substance that donanemab targets.
Donanemab would be the second FDA-approved Alzheimer’s drug on the market that targets amyloid plaque, a substance that forms in the brain that can disrupt cell function, which has become a target in the field of Alzheimer’s treatment—Eisai and Biogen’s anti-amyloid drug, Leqembi, was approved last year.
A study last July found that donanemab significantly slowed cognitive and functional decline in patients with early symptoms of Alzheimer’s—results that the National Institute on Aging called “another set of promising results” in the field of anti-amyloid therapy, following the success of Leqembi.
The most serious potential side effect of anti-amyloid drugs is ARIA, or amyloid-related imaging abnormalities, which can be life-threatening—ARIA was identified in 37% of the patients in the donanemab group of the study, with three dying—and more minor side effects include headaches and nausea, Eli Lilly said.
Eli Lilly noted in its announcement the “unusual” nature of the FDA delay, noting it’s rare for an advisory committee to occur after the FDA action date, but also arguing similar committees were convened for the other FDA processes for amyloid-related treatments—the FDA told Forbes that it cannot comment on possible or pending applications for approval.
What Was ‘unique’ About The Donanemab Study?
The study stopped treatment when patients’ amyloid plaque levels came down and still showed a decline in cognitive functioning—which would differ from other Alzheimer’s treatments that don’t have designated end dates. John Sims, a medical director with Lilly, told the New York Times that this “very unique” element of the study would likely draw the FDA’s attention and prompt questions about whether other similar drugs could also be paused. The study also measured another protein in patients, called tau, which is reportedly associated with memory problems.
Contra
The delay this late in the process prompted surprise from both Eli Lilly and some Alzheimer’s groups. “We were not expecting this,” Anne White, an executive vice president of Lilly, told the Times. The Alzheimer’s Association said the delay was “a surprise,” but noted it “appreciates the (FDA’s) thorough process in reviewing treatments for Alzheimer’s disease.” The Association said it would “strongly urge the FDA to move swiftly in this next stage of its review.”
What To Watch For
The FDA has not yet set a date for the advisory committee meeting, so the precise timing of a potential donanemab approval isn’t known—but Eli Lilly says it expects approval “will be delayed beyond the first quarter of 2024.”
Key Background
These anti-amyloid drugs are not cures for Alzheimer’s—but instead aim to slow the cognitive decline associated with the disease. Donanemab would be the third amyloid-treatment approved by the FDA. Aducanumab was the first amyloid-centric treatment approved by the FDA in 2021, but that drug, marketed by Eisai and Biogen as Aduhelm, has since been pulled from the market. Leqembi was approved in 2023 and remains on the market.
Big Number
47%. That’s the percentage of those in the last donanemab trial who received the drug and saw no signs of cognitive decline after one year of treatment, compared to 29% of patients who received a placebo.
Further Reading
