• Posted May 3, 2023

Experimental Alzheimer's Drug Slows Decline in Thinking in Late-Stage Trial

Another experimental drug meant for Alzheimer's disease looks so promising that drugmaker Eli Lilly plans to ask the U.S. Food and Drug Administration for full approval by the end of June.

Known as donanemab, the medication clears amyloid plaque from the brain. In a late trial, the drug slowed memory and thinking declines in early symptomatic Alzheimer's patients by more than a third, Lilly said Wednesday. About 47% of those taking the medication had no decline on a key measure of thinking over a year, compared to 29% of patients on a placebo.

"We are extremely pleased that donanemab yielded positive clinical results with compelling statistical significance for people with Alzheimer's disease in this trial," Dr. Daniel Skovronsky, Lilly's chief scientific and medical officer and president of Lilly Research Laboratories, said in a company news release. "This is the first Phase 3 trial of any investigational medicine for Alzheimer's disease to deliver 35% slowing of clinical and functional decline."

But there were some risks noted in the results. The Lilly trial involved 1,700 patients, three of whom died during the study. Two of those deaths were attributed to brain swelling or microbleeds called amyloid-related imaging abnormalities (ARIA).

"We are encouraged by the potential clinical benefits that donanemab may provide, although like many effective treatments for debilitating and fatal diseases, there are associated risks that may be serious and life-threatening," said Dr. Mark Mintun, group vice president Neuroscience Research & Development at Lilly. "We note that these results suggest that people in the early pathological stage of disease could be the most responsive to therapeutics targeting amyloid."

About 52% of the patients in the trial were able to stop taking the medication by one year because of its effectiveness. About 72% could do so by a year and a half, the company said.

In the trial, a group with intermediate levels of a brain protein known as tau had a 35% slowing in cognitive and functional decline. In the intermediate group combined with a group with higher tau levels, slowing in decline was 22%.

This new class of medicines is different because of "the amount of amyloid they can clear and how quickly they can clear it,"Skovronsky told CNN.

Another new drug, Eisai and Biogen's Leqembi, was approved in January under an accelerated approval process. It may receive full approval by July, CNN reported.

Lilly has also sought accelerated approval, but the FDA rejected the application in January because it wanted more data, according to CNN.

Donanemab is given by infusion once monthly. Its price has not been announced, but Leqembi's price is $26,500 a year, CNN reported.

More information

The U.S. Centers for Disease Control and Prevention has more on Alzheimer's disease.

SOURCES: Eli Lilly & Co, news release, May 3, 2023; CNN