The Food and Drug Administration (FDA) has delayed the approval of Eli Lilly’s experimental Alzheimer’s drug, donanemab, according to a recent announcement by the company. The FDA plans to convene an advisory meeting to further review the drug’s safety and efficacy in a late-stage trial, leading to a potential approval after this month. The decision reflects the high stakes involved in developing treatments for Alzheimer’s, a condition that currently affects more than six million Americans and has no cure.
Eli Lilly’s donanemab significantly slowed the progression of Alzheimer’s in a late-stage trial. However, like other similar drugs, it carries safety concerns related to brain swelling and bleeding. The FDA’s decision to call for an advisory meeting highlights the need to carefully evaluate the risks and benefits of these treatments. Patients with Alzheimer’s currently have limited effective care options, making the development of innovative therapies crucial.
This delay is another setback for Eli Lilly, as it competes with Biogen and Eisai in the race to find a breakthrough treatment for Alzheimer’s. Biogen and Eisai’s drug, Leqembi, received approval last year as the first medicine proven to slow the progression of the disease in people at the early stages. Both Leqembi and Eli Lilly’s donanemab are monoclonal antibodies targeting amyloid plaque buildups in the brain, a hallmark of Alzheimer’s.
Despite the unexpected delay, Eli Lilly remains confident in donanemab’s potential to offer meaningful benefits to people with early symptomatic Alzheimer’s. The company expressed its willingness to work with the FDA and stakeholders in the community to present the drug’s data and address any questions or concerns.
While it is unusual for the FDA to hold an advisory panel meeting after a set action date, it has done so for other amyloid plaque-targeting therapies that it previously approved. The agency often seeks advice from its advisory panel on the safety and effectiveness of unapproved products. While the FDA typically follows these recommendations, it is not obligated to do so. In 2021, the FDA approved Biogen and Eisai’s Aduhelm, an earlier Alzheimer’s drug, despite a negative recommendation from its advisory panel.
The FDA will carefully examine the 18-month phase three trial of donanemab, which involved over 1,700 patients in the early stages of Alzheimer’s with confirmed amyloid plaque presence. The agency is particularly interested in understanding the safety results and how the trial’s unique design influenced efficacy. Notably, Eli Lilly’s study allowed patients to discontinue the drug once the amyloid plaques were cleared from their brains, unlike other Alzheimer’s drugs such as Leqembi.
In the trial, donanemab demonstrated positive results, with patients experiencing a 35% slower decline in memory, thinking abilities, and daily activities compared to those who did not receive the treatment. However, around 37% of people who took donanemab experienced brain swelling or bleeding, including three deaths, while only around 15% of those who received a placebo experienced such side effects. Similar side effects have also been observed with Leqembi.
As the FDA takes a cautious approach in evaluating donanemab’s safety and efficacy, it remains to be seen when the drug will receive approval. In the meantime, the search for effective treatments for Alzheimer’s continues, and Eli Lilly will continue to navigate challenges in its pursuit of developing a breakthrough therapy for this devastating disease.
