The U.S. Food and Drug Administration (FDA) has approved Kisunla™ (donanemab-azbt), an Alzheimer's treatment developed by Eli Lilly and Company, for adults with early symptomatic Alzheimer's disease (AD). This includes individuals with mild cognitive impairment (MCI) and those in the mild dementia stage of AD, all with confirmed amyloid pathology.
Clinical Efficacy
Kisunla is administered as a once-monthly intravenous infusion and stands out as the first amyloid plaque-targeting therapy with evidence supporting the cessation of treatment once amyloid plaques are cleared. This approach may lead to reduced treatment costs and fewer infusions for patients. In the Phase 3 TRAILBLAZER-ALZ 2 study, participants in the early stages of the disease experienced the most significant benefits. Those with low to medium levels of tau protein showed a 35% slowing of clinical decline compared to placebo, as measured by the integrated Alzheimer's Disease Rating Scale (iADRS). The iADRS assesses memory, thinking, and daily functioning. In the overall study population, a statistically significant 22% slowing of decline was observed.
Amyloid Plaque Reduction
Across the entire participant group, Kisunla reduced amyloid plaques by an average of 61% at 6 months, 80% at 12 months, and 84% at 18 months compared to baseline. A key treatment goal was to reduce amyloid plaques to minimal levels, consistent with a visually negative amyloid positron emission tomography (PET) scan. Participants who achieved these levels were able to switch to placebo for the remainder of the study.
Safety and Side Effects
Treatment with Kisunla can cause amyloid-related imaging abnormalities (ARIA), a potential side effect associated with amyloid plaque-targeting therapies. ARIA may manifest as temporary brain swelling or small spots of bleeding, detectable via MRI scans. While often asymptomatic, ARIA can, in rare cases, lead to serious and life-threatening events. Allergic reactions, some severe, are also a potential risk, typically occurring during or shortly after infusion. Headache is another commonly reported side effect.
Cost and Access
In the TRAILBLAZER-ALZ 2 trial, a proportion of participants were able to complete treatment and switch to placebo after achieving minimal amyloid plaque levels. Specifically, 17% completed treatment at 6 months, 47% at 12 months, and 69% at 18 months. The cost of Kisunla is $695.65 per vial, with total treatment costs varying based on the duration required to achieve amyloid plaque removal. Coverage and reimbursement are available for eligible Medicare patients under a National Coverage Determination with Coverage with Evidence Development. Lilly also intends to donate Kisunla to the Lilly Cares Foundation to provide access to qualified Americans who meet financial criteria.
