New Drug Shows Promise in Slowing Alzheimer's Symptoms

Donanemab is an antibody designed to target amyloid plaques, a protein aggregate believed to cause Alzheimer's by impeding neuron function.

The drug will now advance through the regulatory pipeline of the US Food and Drug Administration (FDA), with a decision expected by the end of the year.

Amyloid plaques have long been associated with Alzheimer's, influencing drug development and treatment approaches. Donanemab's direct binding with the plaques neutralizes and clears them, potentially hindering the progression of Alzheimer's.

The Eli Lilly trial involved 1,736 participants with varying levels of Alzheimer's symptoms. Those receiving donanemab treatment saw a remarkable 84% reduction in amyloid plaque within 18 months, while the placebo group experienced only a 1% reduction. In participants with mild Alzheimer's symptoms, cognitive decline was slowed by 35% as measured by the Alzheimer's Disease Rating Scale (iADRS) and 36% as measured by the Clinical Dementia Rating-Sum of Boxes (CDR-SB). Although specific figures for participants with more severe symptoms were not disclosed, the entire donanemab group experienced an average 22% slowdown as measured by the iADRS and 29% as measured by the CDR-SB.

While the results are promising, there were some downsides observed during the trial. A small fraction of participants experienced brain swelling and bleeding, considered serious side effects. Additionally, donanemab appeared to be slightly less effective in participants aged 75 and over, showing a slowdown of 25% and 29% on the iADRS and CDR-SB, respectively, compared to a 48% and 45% slowdown in those under 75.

Despite these findings, Eli Lilly has applied for FDA approval and hopes to receive a response by the end of 2023. Further research and analysis are needed to fully assess the drug's safety and efficacy in treating Alzheimer's.