Researchers have reported promising results for an experimental Alzheimer’s drug, donanemab, which has shown the ability to modestly slow the inevitable worsening of the disease by about four to seven months.
Developed by Eli Lilly and Co., donanemab is now seeking approval from the Food and Drug Administration (FDA) to become the second treatment for Alzheimer’s shown to delay the progression of the disease.
The recent data was presented at the Alzheimer’s Association International Conference in Amsterdam and published in the Journal of the American Medical Association (JAMA).
The study enrolled 1,700 patients aged 60 to 85 who were in the early stages of Alzheimer’s. Half of the participants received monthly infusions of donanemab, while the other half received dummy infusions over 18 months.
Notably, patients were switched to dummy infusions if sufficient amyloid plaque reduction occurred.
Researchers also tracked the levels of abnormal tau, another marker of the disease’s progression.
The results revealed that both groups experienced a decline throughout the study.
However, the group treated with donanemab exhibited a 22% slower rate of decline compared to the control group.
The drug demonstrated greater effectiveness in patients with lower to medium tau levels, with a 35% slower decline observed. Overall, donanemab slowed disease progression by approximately four to seven months.
Both donanemab and the recently approved Leqembi from Eisai are lab-made antibodies administered intravenously to target sticky amyloid plaques in the brain, a hallmark of
Alzheimer’s disease. However, both drugs carry a serious safety concern of brain swelling or bleeding.
New Hope for Alzheimer’s Treatment, but Questions Remain
The Lilly study linked this adverse event to three deaths.
Approximately 25% of donanemab recipients experienced brain swelling, while around 20% had microbleeds. Patients receiving any amyloid-targeted therapy require repeat brain scans to monitor these potential side effects, which can be both costly and time-consuming.
Despite the positive findings, there are still significant questions regarding which patients would benefit the most from donanemab and similar drugs.
Dr. Eric Widera of the University of California, San Francisco, emphasized in an accompanying JAMA editorial that the modest benefits of amyloid antibodies would be more readily accepted if they were low-risk, inexpensive, and easy to administer.
Additionally, the study primarily involved white participants, highlighting the need for data on how other populations may respond to these treatments.
While donanemab and Leqembi signify a new era in Alzheimer’s therapy, researchers acknowledge the need for additional approaches.
The FDA’s conditional approval of Aduhelm in 2021, a drug targeting amyloid buildup, faced criticism due to the lack of evidence supporting its efficacy. However, the approval of Leqembi and the promising results of donanemab have revitalized efforts to combat amyloid accumulation.
Eli Lilly is also conducting late-stage studies on a tau-fighting drug, further expanding the potential treatment options for Alzheimer’s patients.