Successful treatment slows disease progression in Alzheimer's

A research study published in JAMA this month has reported success in treating people in the early stages of Alzheimer's disease.

The drug, donanemab, is a monoclonal antibody which clears amyloid plaque build-up in the brain by binding to the amyloid and supporting its removal through microglial-mediated phagocytosis.

The study, TRAILBLAZER_ALZ2, was a double-blind, randomised control study, and its primary outcome was to assess the efficacy and adverse events associated with the drug in a larger population after the phase 2 trial had found it to successfully slow disease progression (Mintun 2021).

The trial found that people with early stage Alzheimer's with an amyloid and tau pathology experienced more than 20% slowing of their disease progression over a 76 week period. Additionally, an estimated 47% of participants receiving donanemab had no disease progression at 1 year (measured using the CDR-SB) compared with 29% of participants receiving placebo.

However, there are significant adverse effects associated with the drug. In their mildest form these consist of headaches and increased confusion, but in more severe cases included seizures. 1.6% of those treated with donanemab experienced serious adverse events resulting in hospitalisation and in 3 cases, death.

Several limitations are noted in the study, including that of sample - almost entirely White - of long-term effects given that the timescale was of 76 weeks, and of the adverse events themselves, as the study was conducted during the pandemic and the key adverse event reported was COVID-19.

Read the article here to understand the trial and its outcomes more fully.

Reference: Sims JR, Zimmer JA, Evans CD, et al. Donanemab in Early Symptomatic Alzheimer Disease: The TRAILBLAZER-ALZ 2 Randomized Clinical Trial. JAMA. Published online July 17, 2023. doi:10.1001/jama.2023.13239