In the Pipeline: New Alzheimer’s Treatment Shows Historic Slowing in Cognitive Decline

In Phase 3 clinical trial results released today, Donanemab, manufactured by Eli Lilly, was shown to slow clinical and functional decline by 35% in people with early-stage Alzheimer’s disease versus a placebo. The drug also slowed decline in the ability to perform daily activities such as cooking, shopping, laundry, and household finances by 40%. This is the first Phase 3 trial of any investigational medicine for Alzheimer's disease to show 35% slowing of clinical and functional decline, according to Lilly.  

Donanemab works by reducing plaques of amyloid beta protein in the brain. In Alzheimer’s disease, dense deposits of amyloid beta and a second protein, tau, form tangles that harm the brain’s neurons and contribute to cognitive difficulties such as memory loss. Removing amyloid beta plaques as early as possible likely offers the most promise for slowing disease progression with this type of treatment.

The 18-month study enrolled people with early symptomatic Alzheimer's disease, which includes mild cognitive impairment and the mild dementia stage of disease, with the confirmed presence of Alzheimer’s neuropathology. Participants received Donanemab as a once-monthly infusion.  

“We are encouraged by these clinical trial results and optimistic about a new potential treatment to slow the onset of Alzheimer’s disease,” said Stacy Pagos Haller, President and CEO. “By slowing the progression of the disease, people who show signs of early Alzheimer’s can maintain quality of life and continue to engage in activities that hold value to them.”  

Who would be eligible, if approved? 

To be eligible for the drug, an individual must be diagnosed by a healthcare professional with mild cognitive impairment or mild dementia and have confirmed presence of amyloid plaque in the brain, which is typically detected through spinal taps or specialized PET scans.  

How much would it cost? 

The cost of the drug is not yet known, although amyloid-lowering drugs are currently not covered by Medicare or other insurers. Amyloid-detecting spinal taps and PET scans necessary to qualify for the drug are also not routinely covered by Medicare. 

A bipartisan group of attorneys general this week called on Medicare to cover FDA-approved antibody Alzheimer’s treatments. BrightFocus and 52 other organizations also asked President Biden to expand Medicare coverage to include greater access to amyloid-beta-detecting PET scans used to diagnose Alzheimer’s disease and to cover amyloid-lowering drugs such as Leqembi. 

Next steps 

Lilly said it anticipates submitting results to the FDA this quarter. If approved, Donanemab would be only the second drug in the class of amyloid immunotherapies shown to slow cognitive decline.  

The first, Leqembi (lecanemab), was granted accelerated conditional approval by the FDA in January based on its ability to clear toxic amyloid from the brain. It was shown to slow cognitive decline associated with Alzheimer’s disease by 25%, according to data published by the drug’s developers Eisai and Biogen. The FDA will decide whether to grant Leqembi traditional approval by July 6.  

Watch a recent Q&A with Dr. Sharon Cohen, Toronto Memory Program, about Leqembi, available as part of the free and interactive expert information program, “Zoom in on Dementia and Alzheimer’s.” 

View Alzheimer’s disease resources and learn more about the Alzheimer’s research funded by BrightFocus  Foundation’s Alzheimer’s Disease Research program. 

About BrightFocus Foundation    

BrightFocus Foundation is a premier nonprofit funder of research to defeat Alzheimer’s, macular degeneration, and glaucoma. Through its flagship research programs—Alzheimer’s Disease Research, National Glaucoma Research, and Macular Degeneration Research—the Foundation is currently supporting a $75 million portfolio of 287 scientific projects. BrightFocus has awarded nearly $300 million in groundbreaking medical research funding since inception and shares the latest research findings, expert information, and English/Spanish disease resources to empower the millions impacted by these devastating diseases. Learn more at brightfocus.org.