Alzheimer’s Drug Trial – Small Benefit, Some Risks

The results of an 18-month experimental Alzheimer’s clinical drug trial were released earlier this week, and while research showed some positive results, there are also risks associated with the drug, lecanemab. 

According to a recent New York Times report, drug manufacturers Eisai and Biogen published findings of a study of nearly 1,800 patients with mild Alzheimer’s symptoms showing the drug lecanemab treatment led to moderately less cognition and function decline compared with patients taking a placebo.  At the end of the trial, patients who received lecanemab declined at a rate 27 percent slower than the control group.  However, experts warn that the drug also caused brain swelling or brain bleeding in some patients. 

Lecanemab is given intravenously to patients every two weeks.  It is a monoclonal antibody that targets the amyloid plaques which are found in the brains of people with Alzheimer’s disease.  Years of prior clinical trials targeting these proteins have failed to yield successful cognitive benefits, making the lecanemab trial an exciting finding in A.D. research. 

Larger and longer trials will be needed to clearly establish the safety and efficacy of lecanemab and determine if the cost and risks outweigh the drug’s benefits.  The cognitive benefits of the drug seen in the trial are considered small in terms of meaningful improvement for patients and caregivers.  Financial costs, safety risks, and the need for frequent infusions will all be considered as trials move forward.  The Food and Drug Administration is expected to decide by January 6, 2023, whether to grant lecanemab accelerated approval designation.  This designation will still require further testing of the drug. 

An estimated 6 million Americans and about 30 million people worldwide live with Alzheimer’s and with a rapidly growing senior population, that number is expected to double by 2050, significantly increasing the burden on caregivers and healthcare systems.  Many patients with A.D. also have several other chronic health conditions including diabetes, heart disease, high blood pressure and obesity making safety issues a priority as trials proceed.