On Jul. 9, 2025, Eli Lilly announced that the U.S. Food and Drug Administration (FDA) has approved a label update with a new recommended titration dosing schedule for Kisunla (donanemab-azbt), Lilly’s once-monthly amyloid-targeting therapy for adults with early symptomatic Alzheimer’s disease (AD), which includes people with mild cognitive impairment (MCI) as well as people in the mild dementia stage of AD, with confirmed amyloid pathology.

 In the TRAILBLAZER-ALZ 6 study, the modified titration schedule significantly lowered the incidence of amyloid-related imaging abnormalities with edema/effusion (ARIA-E) versus the original dosing schedule at 24 and 52 weeks, while still achieving similar levels of amyloid plaque removal and P-tau217 reduction.

The new recommended dosing regimen involves a more gradual titration, and the TRAILBLAZER-ALZ 6 study significantly lowered the incidence of ARIA-E by 41% at 24 weeks and by 35% at 52 weeks versus the original dosing schedule. ARIA-E is a side effect of amyloid plaque-targeting therapies, including Kisunla. ARIA-E is usually asymptomatic, although serious and fatal events can occur.

The new dosing recommendation differs from the original dosing by shifting a single vial from the first dose to the third dose, delivering the same amount of Kisunla by week 24. This resulted in lower rates of ARIA-E without compromising Kisunla’s ability to reduce amyloid plaque or Kisunla’s once-monthly dosing with the potential for limited-duration treatment based on amyloid plaque removal to minimal levels.

The primary endpoint of the study was the proportion of participants with any occurrence of ARIA-E by week 24. The results showed the incidence of ARIA-E was 14% in patients receiving the modified titration compared with 24% for those receiving the original dosing regimen, a 41% lower relative risk.

At week 52, the incidence of ARIA-E was 16% in patients receiving the modified titration compared with 25% for those receiving the original dosing regimen, a 35% lower relative risk. No new adverse reactions were identified in this study, although higher rates of hypersensitivity reactions and infusion-related reactions were observed.

The FDA approved Kisunla in July 2024 based on the TRAILBLAZER-ALZ 2 Phase 3 clinical trial data. The study demonstrated that Kisunla significantly slowed cognitive and functional decline in patients who were less pathologically advanced in their disease by up to 35% and by 22% in the overall study population compared to placebo at 18 months. Kisunla reduced the risk of progressing to the next clinical stage of disease by 37% over the same period. Cognitive and functional decline was characterized by more severe memory and thinking problems, more trouble with daily activities, and a greater need for help from caregivers.