Eli Lilly has announced that its experimental medication, donanemab, significantly slowed the cognitive and functional decline of Alzheimer's patients by more than a third in a large clinical trial. The drug works by removing the amyloid plaque buildups in the brain that are a hallmark of Alzheimer's disease. Based on the results, Lilly plans to file for approval from the US Food and Drug Administration (FDA) by the end of June. However, there were three deaths in the trial, two of which were attributed to adverse events such as brain swelling or microhemorrhages, known as amyloid-related imaging abnormalities or ARIA.
Alzheimer's affects more than 6 million Americans, with an estimated 1.7 million to 2 million people over 65 in the early stages of the disease, according to Lilly. Drug development for Alzheimer's has been riddled with failures, but Lilly's drug is among a new group showing promise. The first, Eisai and Biogen's Leqembi, received accelerated FDA approval in January.
The medicine is given by infusion once a month. Donanemab clears amyloid so effectively, the company says, that a majority of patients in the trial – 52% – were able to stop taking the medicine by one year, and 72% were able to do so by a year and a half. Researchers will continue to monitor these patients’ progress.
Lilly filed for accelerated approval with the FDA for donanemab based on earlier results but was rejected in January as the agency sought more data. With these results, the company will file for full approval, which is expected to lead to broader insurance reimbursement for the medicine. Leqembi was approved on an accelerated basis in January, and Medicare is not expected to cover the drug broadly until it receives full approval as well, most likely by early July.
Leqembi is priced at $26,500 a year. Lilly's chief scientific and medical officer, Dr. Daniel Skovronsky, declined to discuss potential pricing for donanemab before the drug is approved. However, he noted that almost half of the participants taking the drug, 47%, showed no decline on a key measure of cognition over the course of a year, compared with 29% of people taking a placebo. Skovronsky said that this was "the kind of efficacy that's never been seen before in Alzheimer's disease."
Overall, the trial results for donanemab are promising, and the drug has the potential to be a significant breakthrough in Alzheimer's treatment. However, the deaths and adverse events reported during the trial are a concern, and the drug's safety profile will need to be closely monitored as it moves towards approval.