Lilly: Eli Lilly's Alzheimer's drug is rejected by EU regulators over brain swelling risk, despite U.S. approval

A flag flies above the headquarters campus of Eli Lilly and Company on March 17, 2024 in Indianapolis, Indiana. - Image: Scott Olson / Staff (Getty Images) The European Union's health regulator on Friday rejected Eli Lilly's ( LLY ) Alzheimer's drug, Kisunla, citing risks of brain swelling and bleeding . It's a major setback for the company as it competes with a similar treatment from Biogen ( BIIB ) and Eisai. The European Medicines Agency's (EMA) Committee for Medicinal Products for Human Use (CHMP) recommended against approving the drug, stating that its benefits did not outweigh its health risks. The EMA still has to make a final decision. "The committee considered that the benefits of this medicine were not large enough to outweigh the risk of potentially fatal events due to amyloid-related imaging abnormalities (ARIA), involving swelling and potential bleedings in the brain," the committee wrote . Kisunla's active ingredient, donanemab, is an antibody designed to target amyloid beta, a protein that forms plaques in the brains of Alzheimer's patients and contributes to cognitive decline. By targeting amyloid beta, the drug is expected to reduce these plaques and slow the progression of the disease. The U.S. Food and Drug Administration (FDA) approved Kisunla last summer as a once-monthly treatment for Alzheimer's - with a warning of ARIA side effects. In a late-stage clinical trial of the drug, patients with mild symptoms experienced a 35% slower decline in memory, thinking, and daily activities compared to those on a placebo. But safety concerns overshadowed the drug's benefits in the CHMP's decision. In a clinical trial, ARIA were significantly more common among Kisunla patients. ARIA occurred in 36.8% of those who received Kisunla, compared to 14.9% of those given a placebo. While most cases were asymptomatic, 1.6% of Kisunla patients experienced serious ARIA events, including three fatal cases. Eli Lilly plans to seek a re-examination of the decision. "Europeans living with early symptomatic Alzheimer's disease and their loved ones urgently need additional treatment options. Today's disappointing CHMP opinion means they must keep waiting," said Ilya Yuffa, executive vice president and president of Lilly International, in a statement . "Donanemab has been reviewed and approved in the United States, Japan, China, and other markets. Lilly remains confident in the safety and effectiveness of donanemab and the value it can bring to patients with early symptomatic Alzheimer's disease." The committee previously rejected Biogen and Eisai's rival drug, Leqembi, before ultimately recommending it for approval last year. "We view the CHMP's negative opinion on Kisunla as unsurprising, given the initial negative opinion for Leqembi, but nonetheless view it as an incremental win for Biogen and Eisai," William Blair analyst Myles R. Minter wrote in a note on Friday. For the latest news, Facebook , Twitter and Instagram .