Eli Lilly’s Alzheimer’s drug wins backing of US advisory panel

Eli Lilly’s Alzheimer’s drug donanemab edged closer to US regulatory approval on Monday, after a panel of independent scientific experts concluded the benefits of the experimental treatment outweighed the risks.

The advisory committee of 11 independent experts convened by the US Food and Drug Administration voted unanimously that donanemab was an “effective” treatment for Alzheimer’s.

But they cautioned more data was needed to understand its effects in patients with low or no levels of tau, a protein linked to Alzheimer’s, because Eli Lilly excluded them from the clinical trial.

Costantino Iadecola, a committee member and professor at Cornell University, said: “If there are some subgroups where further analysis is required, this should not hold up making this drug available to the public.”

Nilufer Ertekin-Taner, a neurogeneticist at the Mayo Foundation, said more data was required for certain groups, including African Americans, Latin Americans and people with Down’s syndrome.

The recommendation is not binding but the regulator typically follows such panels’ advice. The FDA called for the review in March, delaying approval of the treatment, because of concerns about the safety of the drug, which can cause swelling of the brain.

The vote is a boost for the world’s largest drugmaker, whose shares closed up 1.8 per cent on Monday. Mark Mintun, the US group’s vice-president of neuroscience research and development, said it was “pleased with the committee’s unanimous recognition of donanemab’s positive benefit-risk profile”.

Eli Lilly’s drug is one of a new class of treatments that slow cognitive decline in patients in early stages of Alzheimer’s by removing amyloid plaque linked to the disease. Some 7mn Americans and more than 50mn people worldwide suffer from Alzheimer’s but have historically been offered scant treatment options.

Analysts have long expected donanemab would outcompete the only existing Alzheimer’s treatment, Leqembi, as donanemab had a higher efficacy in clinical trials and required monthly rather than fortnightly infusions. Leqembi, which was co-developed by Eisai and Biogen, uses a different mechanism to remove amyloid-plaque from the brain.

But trials of Eli Lilly’s drug have also given rise to safety concerns — three people have died because of brain-swelling incidents.

Leqembi slowed cognitive decline by 27 per cent compared with the placebo group in a phase 3 trial. Donanemab slowed cognitive decline by 35 per cent, albeit with a higher incidence of a rare brain-swelling side effect. Eli Lilly created its own cognition test to measure the trial’s success.

In a briefing document published before Monday’s meeting, FDA staffers suggested Eli Lilly’s drug may require a so-called black-box warning to explain its potential side-effects to patients. They also questioned whether a threshold of tau levels should be used to determine which patients were offered the treatment.

Leerink analysts last week cut their 2030 sales projections for donanemab to $500mn, suggesting it may fall short of so-called “blockbuster” status of $1bn in annual sales and well below analysts’ consensus estimates of $3.7bn for 2030.

Eli Lilly was caught off guard by the FDA’s decision to ask outside experts to review its Alzheimer’s treatment, according to people familiar with the matter.

Leqembi was also scrutinised by an advisory committee before its eventual approval. Controversy surrounding the accelerated approval of Aduhelm — the first Alzheimer’s treatment Eisai and Biogen co-developed — led to three resignations from the FDA advisory panel and criticism from two congressional committees. In January, Biogen relinquished the rights to the drug.