(CNN) An experimental Alzheimer’s drug slowed the decline in patients’ ability to think clearly and complete daily tasks by more than a third in a large clinical trial, drugmaker Eli Lilly said on Wednesday.
Based on the results in people with early symptomatic Alzheimer’s disease, Lilly plans to submit a regulatory submission to the U.S. Food and Drug Administration by the end of June.
The drug donanemab removes deposits in the brain known as amyloid, a hallmark of Alzheimer’s disease. However, some side effects have been reported; There were three deaths in the study among people taking the drug, two of which were attributed to adverse events such as brain swelling or microbleeds known as amyloid-related imaging abnormalities, or ARIA. The study was conducted in more than 1,700 patients for 18 months.
“For every drug, for every disease, there are potential risks and potential benefits,” said Dr. Daniel Skovronsky, Lilly’s Chief Scientific and Medical Officer. However, he found that nearly half of the participants taking the drug, 47%, showed no decline in a key measure of cognition over the course of a year, compared with 29% of those taking a placebo.
That’s “the kind of effectiveness that’s never been seen before in Alzheimer’s disease,” Skovronsky said.
According to Lilly, Alzheimer’s affects more than 6 million Americans, with an estimated 1.7 million to 2 million people over the age of 65 having the early stages of the disease. Drug development for Alzheimer’s has been beset with failures, but Lilly’s drug belongs to a new group that shows promise. The first, Biogen’s Eisai and Leqembi, received accelerated FDA approval in January.
Skovronsky, who noted he has worked in the field of Alzheimer’s disease for 25 years, said the new class of drugs is different because of “the amount of amyloid they can clear and how quickly they can clear it.”
The medicine is given as an infusion once a month. Donanemab is so effective at eliminating amyloid, the company says, that the majority of patients in the study – 52% – were able to stop taking the drug after one year and 72% after a year and a half. Researchers will continue to monitor the progress of these patients.
In the study, the researchers split the participants into two groups based on levels of a brain protein known as tau. A 35% slowdown in cognitive and functional decline was observed in the group with intermediate tau levels, whose disease was not as advanced. When this intermediate group was combined with the group with higher tau concentrations, the figure was 22%. The results were neither peer-reviewed nor published in a journal.
Lilly applied to the FDA for accelerated approval of donanemab based on previous results, but was denied in January when the agency requested more data. With these results, the company will seek full approval, which is expected to lead to broader insurance coverage for the drug. Leqembi received accelerated approval in January, and Medicare is unlikely to provide full coverage for the drug until it also receives full approval, most likely in early July.
Leqembi costs US$26,500 per year. Skovronsky declined to discuss possible prices for donanemab before the drug is approved.