Promising new Alzheimer’s drug seen to slow pace of disease by about a third

A promising new Alzheimer’s drug has been shown to slow the pace of the disease by about a third– a feat experts previously thought impossible.

The drug, donanemab, from the pharmaceutical company Eli Lilly, is the second in under a year to have been shown to slow Alzheimer’s. It does so by removing sticky amyloid plaques- a hallmark sign of the disease- from the brain.

“We are extremely pleased that donanemab yielded positive clinical results with compelling statistical significance for people with Alzheimer’s disease in this trial,” said Daniel Skovronsky, M.D., Ph.D., Lilly’s chief scientific and medical officer, and president of Lilly Research Laboratories in the company’s news release. 

“This is the first Phase 3 trial of any investigational medicine for Alzheimer’s disease to deliver 35 per cent slowing of clinical and functional decline.” 

In the company’s trial, there were 1,182 participants with early-stage disease whose brains had deposits of two key Alzheimer;s proteins, beta amyloid as well as intermediate levels of tau, a protein linked with the disease progression and brain cell death.

Elli Lilly says the trial participants received a monthly intravenous infusion of donanemab, and at 12 months, half of them had no evidence of amyloid plaques.

Overall, the pace of the disease was slowed by about 29 per cent. And in a set of patients researchers thought more likely to respond, the clinical decline of the disease was at 35 per cent compared to a placebo. 

There still seem to be risks associated with the drug, however, as two volunteers, and possibly a third, died from dangerous swelling in the brain. 

This brain swelling was a common side effect in up to a third of patients as well.

Dr Ronald Petersen, an Alzheimer’s researcher at Mayo Clinic, said Lilly’s trial is the third to show removing amyloid from the brain slows progression of the disease, which could lessen doubts about the drug’s benefits.

“It’s modest, but I think it’s real and I think it’s clinically meaningful,” said Petersen about Lilly’s trial results.

Many researchers are excited about donanemab’s potential, such as Dr Susan Kolhaas from Alzheimer’s Research UK, who told the BBC: “We’re now on the cusp of a first generation of treatments for Alzheimer’s disease, something that many thought impossible only a decade ago.”

Eli Lilly said it planned to file for traditional US approval by the end of June, followed by regulators from other countries. 

More than 11 million women in the US are either living with Alzheimer’s or caring for someone who has it, according to the Alzheimer’s Association. And the total number of Alzheimer’s patients aged 65 and older is expected to rise to nearly 13 million in the US by 2050.

A US approval decision is expected to come by the end of the year or into early 2024.