The US Food and Drug Administration (FDA) has postponed its decision on the approval of donanemab, an experimental Alzheimer’s drug developed by Eli Lilly. Initially expected by the end of 2023, this delay constitutes the second regulatory hurdle the drug has faced, pushing the decision timeline further out. Lilly’s donanemab is designed to target and clear out amyloid plaques in the brain, a hallmark of Alzheimer’s disease, and it has shown promise in clinical trials by slowing memory and cognitive decline by up to 35% in early-stage patients.

This postponement comes as the FDA seeks to delve deeper into the safety and efficacy of donanemab, prompted by concerns over brain swelling and bleeding observed in trial participants. The agency has also expressed interest in understanding the drug’s effects on tau protein levels, another key factor in Alzheimer’s progression. An expert advisory committee is set to meet to review these aspects before making a decision.

The delay has elicited surprise from Anne White, the president of Lilly Neuroscience, especially given that this isn’t the first time a drug from this category has required such rigorous review. The Alzheimer’s treatment landscape remains competitive and complex, with ongoing comparisons to other treatments like Leqembi. Despite the regulatory challenges, Lilly remains optimistic about donanemab’s potential to significantly benefit patients with early symptomatic Alzheimer’s, given its novel approach to targeting the disease’s underlying pathology.

Alzheimer’s disease affects over 6 million Americans, making the pursuit of effective treatments a priority in the medical field. With a projected $1 billion in sales by 2026, the approval process of donanemab is closely watched for its potential impact on patients, healthcare providers, and the broader pharmaceutical industry engaged in Alzheimer’s research and treatment.