Eli Lilly announced on Friday, revealing that the Food and Drug Administration (FDA) has extended the deadline for its decision on the approval of the pharmaceutical company’s experimental Alzheimer’s treatment, donanemab.
This unexpected move by the agency involves convening a last-minute meeting with external advisors to conduct a more thorough review of the treatment’s safety and efficacy in a late-stage trial, as stated by Eli Lilly. The FDA has not disclosed the date of this meeting, indicating that potential approval would likely be deferred beyond this month.
Initially, the FDA was anticipated to decide on whether to approve the medication by the end of the first quarter, a deadline already postponed from an expected approval last year.
Eli Lilly’s drug showcased significant effectiveness in slowing the progression of Alzheimer’s in a late-stage trial. However, safety concerns, particularly related to brain swelling and bleeding, accompany this treatment, along with similar drugs.
The FDA’s decision to call for an advisory meeting underscores the considerable challenges in developing treatments for Alzheimer’s, a condition affecting over 6 million Americans with no current cure, leaving patients with limited care options.
This delay marks another setback for Eli Lilly, as it competes with Biogen and Eisai in the race to provide effective treatments. Leqembi, their competitor’s treatment, received approval last year, marking the first medication proven to slow Alzheimer’s progression in individuals at the early stages of the disease.
Both Leqembi and Eli Lilly’s drugs are monoclonal antibodies targeting the buildup of amyloid plaque, a protein in the brain considered a hallmark of Alzheimer’s disease.
Despite labeling the delay as “unexpected,” Eli Lilly remains confident in donanemab’s potential to offer significant benefits to individuals with early symptomatic Alzheimer’s disease, as stated in a release by Anne White, president of neuroscience at Eli Lilly.
Eli Lilly highlighted the rarity of the FDA holding an advisory panel meeting after a predetermined action date, mentioning similar meetings convened for two other FDA-approved therapies targeting amyloid plaque.
While the FDA typically considers the recommendations of its advisors, it is not obligated to do so. In 2021, the FDA approved Aduhelm, an earlier Alzheimer’s drug from Biogen and Eisai, despite a negative recommendation from the agency’s advisory panel.
The FDA will scrutinize an 18-month phase 3 trial, which monitored over 1,700 patients in the early stages of Alzheimer’s with confirmed amyloid plaque presence. The agency aims to assess safety outcomes and evaluate how the trial’s distinctive design influenced efficacy.
Eli Lilly’s study permitted patients to discontinue the drug once amyloid plaques were cleared from the brain, unlike other Alzheimer’s drugs such as Leqembi, which lack designated stopping points.
In the trial, Eli Lilly’s drug demonstrated positive outcomes, with patients receiving the treatment exhibiting a 35% slower decline in memory, cognitive abilities, and daily functioning compared to those who did not receive it.
However, the trial reported brain swelling or bleeding in 37% of individuals who took donanemab, including three fatalities, compared to around 15% of those who received a placebo. Similar side effects have been observed in Leqembi as well.
