Donanemab Shows Promise in Slowing Early-Stage Alzheimer's Cognitive Decline

Hot on the heels of full FDA approval of the early Alzheimer’s drug Leqembi, a new JAMA study suggests that investigational drug donanemab looks beneficial for early stages of the neurodegenerative disease that affects more than six million Americans.

Donanemab Delayed Alzheimer’s

In the TRAILBLAZER-ALZ 2 randomized clinical trial, researchers investigated the efficacy and safety of the monoclonal antibody targeting amyloid beta. According to prevailing theories, the hallmark pathology of Alzheimer’s disease is the accumulation of amyloid beta protein in the brain. The formation of plaques interferes with brain function, ultimately leading to cognitive decline and dementia.

The study included 257 participants who were randomized to receive either donanemab or a placebo every four weeks for up to 72 weeks. All participants had early symptomatic Alzheimer’s disease and showed evidence of amyloid beta pathology on imaging.

New Alzheimer’s Drug Leqembi is Granted Full FDA Approval

Alzheimer’s Disease Clinical Resource Center

Amyloid Burden and Depressive Symptom Trajectories

The primary measure of the study was the change from baseline to 76 weeks in the Integrated Alzheimer’s Disease Rating Scale (iADRS) score, which measures cognitive and functional performance. Donanemab was associated with a significant slowing of cognitive and functional decline compared to placebo. At 76 weeks, the mean change in iADRS score was a decline of 6.86 points in the donanemab group compared to a decline of 10.06 points in the placebo group. The researchers said this represented a significant difference between the two groups.

Positive Response

The data, reported by Eli Lilly and Company, was unveiled at the Alzheimer’s Association International Conference (AAIC) in Amsterdam. Expert reactions have been favorable.

“The data released today is very good news for Alzheimer’s patients who could soon have yet another treatment option to effectively combat Alzheimer’s disease,” George Vradenburg, chair and co-founder of UsAgainstAlzheimer’s, said in a statement. “We urge the Food and Drug Administration (FDA) to expedite the approval process for donanemab, recognizing the narrow window thousands of Americans with early-stage Alzheimer’s have to benefit from the full effects of the treatment.”

Howard Fillit, MD, Co-Founder and Chief Science Officer of the The Alzheimer’s Drug Discovery Foundation (ADDF), also expressed optimism.

“Today’s results are promising, with donanemab slowing cognitive decline by 35% in patients with early-stage Alzheimer’s disease, making it all the more apparent that anti-amyloid therapies will serve as the first line of defense in the arsenal of drugs needed to treat this disease,” Fillit said. 

Some Risks

Donanemab does carry risks. The drug had a higher incidence of amyloid-related imaging abnormalities (ARIA). These problems are related to brain imaging and can occur with drugs that target amyloid beta, resulting in symptoms such as headaches and confusion. In the study, 27 percent of participants in the donanemab group had ARIA, compared to just three percent in the placebo group.

The researchers suggested the need for further study to confirm the benefits of donanemab. But experts are heartened to see another therapy show promise after decades of failure. These latest results provide hope for patients with Alzheimer’s disease and underscore the importance of early diagnosis and treatment.