These findings were greeted with enthusiasm by experts, who hailed the entry into a "new era" in Alzheimer's care, thanks to several recent breakthroughs.

The clinical trial, which included 1,200 participants who had not yet reached an advanced stage of the disease, showed a 35 percent reduction in cognitive decline in patients treated with donanemab, according to a company statement.

Eli Lilly plans to file an application for authorization with the U.S. Food and Drug Administration (FDA) as early as this quarter, and worldwide "as soon as possible".

However, treatment can cause serious side effects, such as edema or cerebral hemorrhage. Three participants in the clinical trial died.

The clinical trial also measured the ability to perform everyday tasks, such as driving, conversing, having hobbies or managing finances. Over 18 months, participants who received the treatment had a 40% reduction in decline in their ability to perform these tasks.

"These results confirm that we are entering the era of Alzheimer's treatment," said Catherine Mummery of the National Hospital for Neurology and Neurosurgery in London.

It will now be possible "to realistically hope to be able to treat and stabilize a person with Alzheimer's disease, with long-term management, rather than palliative and supportive care," she added.

Research in the fight against Alzheimer's disease has stagnated for decades.

But two new treatments, developed by the Japanese pharmaceutical companies Eisai and the American Biogen, have recently been approved in the United States: Leqembi (whose active ingredient is called lecanemab), and Aduhelm (molecule aducanumab).

While the approval of Aduhelm has been controversial, with some experts pointing to the lack of evidence on its effectiveness, lecanemab was the first to demonstrate a reduction in cognitive decline (by 27%) in a clinical trial.

Eli Lilly's treatment, if "approved alongside lecanemab", could "offer patients a choice of treatments", said Liz Coulthard of the University of Bristol.

Alzheimer's disease affects tens of millions of people worldwide.

© 2023 AFP