Eli Lilly discloses FDA complete response letter for submission of donanemab

The company states: "Eli Lilly announced the FDA has issued a complete response letter for the accelerated approval submission of donanemab for the treatment of early symptomatic Alzheimer’s disease due to the limited number of patients with at least 12 months of drug exposure data provided in the submission. No other deficiencies in the application were noted. The confirmatory Phase 3 TRAILBLAZER-ALZ 2 trial remains ongoing, with topline data read-out expected in Q2 2023, and will form the basis of donanemab’s application for traditional approval shortly thereafter. Lilly will continue to work with the FDA to evaluate the fastest pathway to make this potential treatment option widely available to patients. In the complete response letter to the accelerated approval application, 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. Donanemab’s specificity to target deposited amyloid plaque informed the unique clinical trial design of TRAILBLAZER-ALZ, which allowed patients to complete their course of treatment when they reached a predefined level of amyloid plaque clearance. While the trial included more than 100 patients treated with donanemab, due to the speed of plaque reduction, many patients were able to stop dosing as early as 6 months of treatment, resulting in fewer than 100 patients receiving 12 months of donanemab. The FDA indicated that the data to meet the exposure expectation would likely need to include the unblinded controlled safety data from TRAILBLAZER-ALZ 2 upon completion. The safety profile of donanemab was initially reported from the TRAILBLAZER-ALZ trial in the New England Journal of Medicine. The safety profile of donanemab has remained consistent since our accelerated approval submission."