(CNN) An experimental drug for Alzheimer’s disease slowed declines in patients’ ability to think clearly and perform 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 said it plans to file for approval with the U.S. Food and Drug Administration by the end of June. .
The drug, donanemab, works by breaking down plaque buildups in the brain called amyloids, which are a hallmark of Alzheimer’s disease. However, some side effects have been reported; there were three deaths in the trial among people taking the drug, two of which were attributed to adverse events such as brain swelling or microhemorrhages, known as brain-related imaging abnormalities amyloid or ARIA. The trial was conducted on more than 1,700 patients for 18 months.
“For every drug, for every disease, there are potential risks and potential benefits,” said Lilly Scientific and Medical Director Dr. Daniel Skovronsky. But he noted that nearly half of 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.
It’s “the kind of efficacy that’s never been seen before in Alzheimer’s disease,” Skovronsky said.
Alzheimer’s disease affects more than 6 million Americans, with about 1.7 to 2 million people over the age of 65 in the early stages of the disease, according to Lilly. Drug development for Alzheimer’s disease has been riddled with failures, but Lilly’s drug is among a promising new group. The first, Leqembi from Eisai and Biogen, received accelerated FDA approval in January.
Skovronsky, who noted that 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 remove and the speed with which they can eliminate it”.
The drug is given by infusion once a month. Donanemab removes amyloid so effectively, according to the company, that the majority of patients in the trial – 52% – were able to stop taking the drug after a year, and 72% were able to do so after ‘a year and a half. Researchers will continue to monitor the progress of these patients.
In the trial, researchers looked at participants in two groups, separated by levels of a brain protein known as tau. A 35% slowing of cognitive and functional decline was observed in the group with intermediate levels of tau, whose disease had not progressed as far. When this intermediate group was combined with the group with higher levels of tau, the figure was 22%. The results have not been peer reviewed or published in a journal.
Lilly applied for accelerated approval with the FDA for donanemab based on earlier results, but was denied in January as the agency sought more data. With these results, the company will file for full approval, which should lead to broader insurance reimbursement for the drug. Leqembi received fast track approval in January, and Medicare is not expected to broadly cover the drug until it receives full approval, most likely in early July.
Leqembi costs $26,500 per year. Skovronsky declined to discuss donanemab’s potential price before the drug was approved.