FDA Stalls on New Alzheimer's Drug

Eli Lilly's experimental Alzheimer's drug is facing yet another delay on the path toward FDA approval. The company's donanemab medication was first expected to be cleared last year and later by the end of this month. However, the drugmaker announced Friday that approval isn't expected until after March as the FDA intends to call a last-minute meeting of outside advisers to review the safety of the drug and the design of its unique Phase 3 trial. "We were not expecting this," Eli Lilly Neuroscience President Anne White tells the New York Times, saying the move came at an unusual time, "at the end of the review cycle and beyond the action date that the FDA had given us."

No date for the meeting has been set, though Eli Lilly believes it could be months away. Despite the disappointment, White said in a statement the company is "confident in donanemab's potential to offer very meaningful benefits to people with early symptomatic Alzheimer's disease." In the Phase 3 trial, a once-a-month donanemab infusion resulted in a 35% slower decline in the ability to think clearly and perform daily tasks in patients with "intermediate" levels of the Alzheimer's-related protein tau, compared with those taking a placebo, and resulted in a 22% slower decline for all participants with "intermediate" and "high" tau levels, per CNN. If approved, donanemab would be the second drug to market shown to slow progression of Alzheimer's disease, following Eisai and Biogen's Leqembi.

Both drugs target amyloid plaques in the brain and have been associated with brain swelling and micro-hemorrhages known as amyloid-related imaging abnormalities (ARIA). "In donanemab's Phase 3 clinical trial, 37% of participants had ARIA, including three who died," CNN reports, adding "Leqembi has been tied to patient deaths as well, although its rate of ARIA was lower in trials." Donanemab's trial design was unique in that patients stopped receiving the drug after their amyloid plaques reached a certain level "and their cognitive decline kept slowing," per the Times. This is likely of interest to the FDA as Leqembi and other Alzheimer's drugs "don't have designated stopping points," per CNN. (More Alzheimer's disease stories.)