Eli Lilly & Company’s experimental drug donanemab, intended to treat Alzheimer’s disease, was expected to be approved by the FDA this month. However, the FDA announced that it would convene a panel of external advisors to review the drug’s safety and efficacy before making a final decision later this year. While this decision was unexpected, some experts believe a cautious approach is necessary given the limited evidence of the drug’s benefits in early trials.
Donanemab is one of three monoclonal antibody treatments targeting amyloid plaques in the brain, a hallmark of Alzheimer’s disease. While drugs like aducanumab and lecanemab have received accelerated approval from the FDA based on promising trial results, donanemab’s approval has been delayed due to concerns about its efficacy and safety profile. In a trial last year, donanemab showed some positive effects on slowing cognitive decline in early Alzheimer’s patients but also led to brain swelling and other adverse effects.
Dr. Howard Fillit of the Alzheimer’s Drug Discovery Foundation explained that the FDA’s decision to establish a committee to evaluate donanemab was likely due to concerns about the drug’s unique dosing schedule, safety signal, and the use of tau imaging in the trial. However, Dr. Clifford Segil, a neurologist, expressed hope that the FDA committee would ultimately not approve donanemab due to the drug’s associated risks, including cerebral edema and intracranial bleeding. He believes that these risks outweigh any potential benefits for Alzheimer’s patients.
While currently available treatments for Alzheimer’s can help manage symptoms, they do not alter the course of the disease. In a phase 3 trial, donanemab demonstrated a 35% reduction in cognitive decline in individuals with low to medium levels of tau protein. However, concerns remain about the potential risks of amyloid-related imaging abnormalities (ARIAs), which can lead to brain swelling or bleeding. Monitoring for these side effects and ensuring appropriate dosing will be crucial if donanemab is ultimately approved by the FDA.
Dr. Fillit remains optimistic about the approval of donanemab, citing the trial data and safety measures in place to mitigate potential risks. He emphasized the need for careful monitoring, especially in individuals with certain genetic factors that may increase the risk of adverse effects. However, Dr. Segil remains skeptical about the benefits of drugs like donanemab, arguing that the risks associated with these medications outweigh any potential benefits for Alzheimer’s patients. He hopes that the FDA’s decision to review donanemab will signal a shift away from anti-amyloid medications in the treatment of Alzheimer’s disease.
In conclusion, the FDA’s decision to review donanemab reflects ongoing concerns about the safety and efficacy of anti-amyloid drugs for Alzheimer’s disease. While some experts remain hopeful about the potential benefits of donanemab, others believe that the risks associated with these medications may outweigh any advantages. As the committee evaluates the data on donanemab, it will be crucial to consider both the potential benefits and risks for patients with Alzheimer’s disease and to ensure that appropriate monitoring and safety measures are in place.
