The U.S. Food and Drug Administration (FDA) has approved donanemab-azbt, 350 mg/20 mL once-monthly injection for IV infusion (Kisunla), a treatment for adults with early symptomatic Alzheimer's disease (AD), which includes people with mild cognitive impairment (MCI) as well as people with the mild dementia stage of AD, with confirmed amyloid pathology.
The FDA approval was based on the TRAILBLAZER-ALZ 2 Phase 3 study, Individuals with the least advanced Alzheimer disease experienced the strongest results with donanemab in the phase 3 TRAILBLAZER-ALZ 2 study. Participants were analyzed over 18 months in 2 groups: (1) a group who was less advanced in their disease (participants with low to medium levels of tau protein) and (2) the overall population, which also included participants with high tau levels. Treatment with donanemab significantly slowed decline in both groups, but those treated with donanemab who were less advanced in their disease showed a significant slowing of decline of 35% compared with placebo on the integrated Alzheimer's Disease Rating Scale (iADRS). The response to treatment in the overall population was also statistically significant using the iADRS at 22%. Among the 2 groups, participants treated with donanemab had up to a 39% lower risk of progressing to the next clinical stage of Alzheimer disease than those receiving placebo.
On average, donanemab reduced amyloid plaques among the overall population of participants by 61% at 6 months, 80% at 12 months, and 84% at 18 months compared with the start of the study. One of the study goals was to remove amyloid plaques to minimal levels consistent with a visually negative scan using amyloid positron emission tomography. Then, if participants were confirmed to have reached these levels, they were able to complete treatment with donanemab and switch to placebo for the remainder of the study.