The U.S. FDA has rejected Eli Lilly’s bid for an accelerated approval of its experimental Alzheimer’s disease drug, donanemab, the company announced.
The agency issued a complete response letter for Lilly's accelerated approval submission of its anti-amyloid biologic for the treatment of early symptomatic Alzheimer's disease. According to Lilly, the CRL was due to the limited number of patients with at least 12 months of drug exposure data provided in the submission.
The accelerated approval application was based on TRAILBLAZER-ALZ phase 2 study showing amyloid plaque lowering. According to data from the 272-patient study, participants who received the drug had a 32% deceleration in the rate of decline, compared with those who got a placebo. However, in the study, patients stopped receiving donanemab and switched to placebo once their plaque reached a certain level for clearance.
In the CRL the FDA specifically requested that Lilly provide data from at least 100 patients who received a minimum of 12 months of continued treatment on donanemab.
The confirmatory phase 3 TRAILBLAZER-ALZ 2 trial for donanemab remains ongoing, with topline data read-out expected in Q2 of 2023. According to Lilly, this will form the basis of its application for traditional approval.