FDA advisory panel votes in favor of Lilly’s Alzheimer’s drug

In a unanimous vote on June 10, 2024, the United States FDA Peripheral and Central Nervous System Drugs Advisory Committee voted in favor of approving donanemab, Eli Lilly’s newest Alzheimer’s disease (AD) drug. While the committee vote does not indicate final FDA approval, the administration heavily considers the committee’s opinions when finalizing decisions on new medications.

Initially, the drug was supposed to be approved earlier in 2024; however, in March, the FDA requested an independent advisory committee to review the drug after some clinical trial participants experienced adverse events, including brain swelling and bleeding.

However, this decision indicates that the panelists believe the drug's benefits outweigh the potential risks.

Among the documents submitted to the advisory panel for review, Eli Lilly presented data from a 76-week, multicenter, randomized, double-blind, placebo-controlled, phase 3 clinical trial called the TRAILBLAZER-ALZ 2. The results of this study were published in JAMA on July 17, 2023.

According to the 2023 JAMA publication, donanemab is a monoclonal antibody that addresses the buildup of amyloid plaque in patients with AD. More specifically, the medication is an immunoglobulin G1 monoclonal antibody that “binds to N-terminal truncated form of β-amyloid and aids plaque removal through microglial-mediated phagocytosis.” Similar drugs include Eisai and Biogen’s Leqembi.

The study randomized 1,736 participants with early symptomatic AD and amyloid and tau pathology, looking at the change in Alzheimer’s Disease Rating Scale (ADRS) scores as an indicator of the drug’s efficacy. The scale gives patients a score between 0 and 144, with lower scores indicating disease progression and more significant impairment.

Researchers found that donanemab slowed disease progression compared to a placebo. For example, across the study population, patients on donanemab had a 10.19-point reduction in ADRS score, while the placebo group had a more significant reduction of 13.11 points.

A focus on the low/medium tau population revealed that donanemab patients only had a 6.02-point reduction in ADRS, while placebo patients had a 9.27-point reduction.

While the drug is not a cure for the condition, data from this study indicates that it could be effective in slowing disease progression.