January 20, 2023
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The FDA has issued a full response letter for early approval of donanemab for the treatment of early-symptomatic Alzheimer’s disease, citing the limited number of patients with long-term drug exposure data.
In a press release, the manufacturer, Eli Lilly, said the agency had specifically requested that the FDA provide data from at least 100 patients who had received at least 12 months of continuous treatment with donanemab.

The FDA has issued a full response letter for accelerated approval of donanemab for the treatment of early symptomatic Alzheimer’s disease. Source: Adobe Stock
The company said the early approval application is based on data from a Phase 2 trial that showed a reduction in amyloid plaques in the brain. Phase 3 trials are still ongoing and data are expected in the second quarter of 2023.
According to Eli Lilly, the specificity of donanemab in targeting deposited amyloid plaques will inform the clinical trial design of the current phase 3 trial, in which patients will be able to respond when amyloid plaque clearance reaches a predetermined level. I was able to complete the course of treatment.
According to Eli Lilly, the phase 2 trial included more than 100 patients treated with donanemab, but plaque reduction was so rapid that many patients were able to discontinue treatment after six months. Fewer than 100 patients received 12 months of donanemab. .
“We look forward to the next confirmatory Phase 3 results and subsequent submission to the FDA, which we have always considered to be the most impactful next step for patients.” Anne White, Executive Vice President and President of Lilly Neuroscience said in the release: “This study confirms the benefit and safety profile observed in the Phase 2 study, and will allow Phase 3 data to be combined with Phase 2 data when patients and physicians need to make treatment decisions. We believe that making available will serve you well.”
The Alzheimer’s Drug Discovery Foundation (ADDF) has issued a statement in response to the FDA’s request.
“This drug did what it was intended to do: clearing amyloid plaques in the brain. treatment was discontinued.” Howard Filitt, M.D., Co-founder and Chief Scientific Officer of the Foundation, according to a press release from ADDF. “In some cases, this occurred in less than 12 months, which is why fewer patients remained on the drug for a year.”
The Alzheimer’s Association also responded with a statement that it “appreciates” the FDA’s systematic process in considering treatments for AD.
“The FDA’s decision that additional data is needed to reach a decision on accelerated approval of donanemab demonstrates the FDA’s rigorous approach when reviewing individual therapies,” the association said. said in a press release.
Earlier this month, the FDA granted accelerated approval for Leqembi (lecanemab-irmb, Eisai) for the treatment of AD. This was his second accelerated approval of an Alzheimer’s drug by the agency after he approved Aduhelm (aducanumab, Biogen/Eisai) in June 2021.
References:
ADDF statement regarding the FDA’s decision not to grant accelerated approval of donanemab for the treatment of Alzheimer’s disease. https://www.alzdiscovery.org/news-room/announcements/addf-statement-on-fda-decision-not-to-grant-accelerated-approval-to-donanemab-for-treat-of-alzheimers-disease. Published January 19, 2023. Accessed 20 January 2023.
Alzheimer’s Association Statement on FDA’s Full Response on Donanemab. https://www.alz.org/news/2023/donanemab-fda-complete-response-letter. Published 19 January 2023. Accessed 20 January 2023.