MRI detects ARIA in 21% of real-world donanemab patients

Brain MRI scans detected amyloid-related imaging abnormalities (ARIA) in 21% of patients receiving donanemab for early Alzheimer's disease, a group at a regional memory center has reported. 

A team from the Norton Neuroscience Institute in Louisville, KY, tracked ARIA on surveillance brain MRI scans in patients receiving donanemab over the drug's first year in clinical use, with findings suggesting the antibody can be safely administered in a real-world setting with structured monitoring. 

"To our knowledge, there are no real-world reports of safety and experience with donanemab in routine clinical settings," noted lead author Lisa Shields, MD, and colleagues. The study was published August 18 in Alzheimer's & Dementia: Diagnosis, Assessment & Disease Monitoring. 

Two types of brain MRI signal abnormalities may be detected on surveillance scans during donanemab (Kisunla , Eli Lilly) treatment: ARIA-edema/effusion (ARIA-E) and ARIA-cortical superficial hemosiderosis/microhemorrhages (ARIA-H), the authors wrote. ARIA-E are characterized by edema (swelling) and/or effusion, and ARIA-H, by hemorrhage. While patients who develop ARIA are usually asymptomatic, severe ARIA may occur with or without symptoms and lead to discontinuation of treatment. 

Surveillance brain MRI scans in clinical trials detected ARIA in 26.1% to 30.5% of patients across the donanemab trial program, the group noted, yet rates in community practice have remained uncharacterized. 

To bridge the gap, the researchers conducted a retrospective review of 51 patients (mean age, 74.3 years old) who received at least one donanemab infusion between October 2024 and October 2025: 30 (58.8%) had mild cognitive impairment and 21 (41.2%) had mild AD. Of these, 48 underwent at least one surveillance brain MRI. 

Gradient recalled echo (GRE) and susceptibility weighted imaging (SWI) were used to assess microbleeds and cortical superficial hemosiderosis, while fluid attenuated inversion recovery (FLAIR) was used to detect edema and effusion. A neuroradiologist read all scans using a standardized ARIA grading system. 

According to the results, of the 48 patients who underwent at least one surveillance MRI, 10 (21%) had an ARIA detected. Genetically-susceptible APOE ε4 carriers more frequently developed ARIA compared to non-carriers, and no patients developed symptomatic ARIA. Eight patients (16%) discontinued donanemab: five due to ARIA progression, two due to severe infusion reactions, and one due to newly diagnosed atrial fibrillation requiring anticoagulation, the researchers reported. 

"Donanemab may be safely used in a real-world setting," the group wrote.   

Larger multicenter data are needed to benchmark real-world ARIA rates, the authors wrote. A modified dose titration regimen may also lower ARIA risk compared to traditional dosing in community populations, they added, and warrants further evaluation. 

The full study is available here.