Sally Osmer didn’t hesitate when her doctors at Duke Health offered lecanemab as a treatment after she was diagnosed with early-stage Alzheimer’s disease at age 74.

Contact

Stephanie Lopez

Director

Email

DURHAM, N.C. – As new Alzheimer’s drugs move from clinical trials into everyday care, families are asking whether these treatments are safe, how long patients can stay on them, and whether they truly slow the disease outside tightly controlled studies.

Researchers at Duke Health studied more than 230 patients treated with lecanemab, a new FDA-approved therapy (known as an anti-amyloid therapy) designed to remove a protein linked to Alzheimer’s disease from the brain.

They found the therapy’s real-world safety, treatment persistence, and effects on disease progression aligned with results from clinical trials – including the most closely watched side effect, which involves brain swelling or bleeding, commonly referred to as Amyloid Related Imaging Abnormalities (ARIA).

The study was published in Neurology Open Access on August 7.

“There’s been a lot of fear about this medication, especially around brain swelling and bleeding,” said study corresponding author, Andrew (Andy) Liu, M.D., associate professor in the departments of Neurology and Pathologyat Duke University School of Medicine. “What we found is that, in the real world, with careful selection and close monitoring, approximately 80% of patients are able to remain on lecanemab for at least one year. Importantly, most treatment-related side effects resolve over time without the need for additional medications or hospitalizations."

The study followed patients with early Alzheimer’s disease or mild memory impairment who received lecanemab at Duke between 2023 and 2025, tracking side effects, MRI scans, cognitive testing, and whether patients remained on therapy up to 396 days. Researchers used specialized MRI sequences to detect small areas of bleeding in the brain.

They found 79% of patients who started treatment were able to continue it, and the 21% who discontinued the drug did so mostly due to adverse events.

About one in four patients (24.3%) developed ARIA. Key findings for this group:

• People with a specific high‑risk Alzheimer’s gene (APOE ε4 homozygotes) were about four times more likely to develop ARIA. Rates for this group did not differ by sex.
• ARIA events could continue up to 30 weeks after starting therapy, showing the importance of continued close monitoring. Two peaks around 10 weeks and 25 weeks were observed.
• A significant minority of patients (31%) had serious adverse events during treatment. The most common were infusion reactions, falls or strokes; however, some events were not necessarily directly attributable to the drug but to the patient’s other illnesses.
• ARIA status was not associated with rates of change in cognitive performance at 12 months.

The study also found that seven commonly available clinical, blood and imaging tests –either alone or combined – could not yet reliably predict who would develop ARIA. Of these, one method (an MRI measure of vascular changes and blood levels of the biomarker pTau/AB42) showed the most promise for identifying subjects at low risk for developing ARIA.

As part of its safety strategy for the study, Duke Health researchers also piloted an imaging tool supported by artificial intelligence (AI) to help detect subtle ARIA changes earlier and more consistently on brain scans, strengthening patient monitoring. The team expects to expand its use soon.

“Cerebral amyloid angiopathy (CAA), a condition characterized by silent buildup of amyloid in the brain's blood vessels, is present in over 50% of all Alzheimer's patients, and is one of the mechanisms thought to underlie ARIA,” said P. Murali Doraiswamy, MBBS, study co-author and professor in the departments of Psychiatry and Behavioral Sciences and Medicine at Duke. “Our study highlights the urgent need to develop better tests to predict who will develop serious ARIA and to know when it is safe to resume treatment.”

Duke Health has now treated more than 400 patients with lecanemab, making it one of the most experienced centers in the country using anti-amyloid therapies. Liu also curates a biorepository in the Duke School of Medicine’s Department of Neurology with blood and cerebrospinal fluid from treated patients that the team hopes to use to develop better biomarkers for CAA and ARIA.

“The decision of whether or not these new medications are right for you is highly individualized,” said Heather Whitson, M.D., co-author of the study and co-director of the Duke & UNC Alzheimer’s Disease Research Center. “We at Duke are on the leading edge of generating real-world evidence and AI tools to help you and your doctor make the right personalized medicine choice for you and improving safety for those who do go on treatment.”

Sally Osmer didn’t hesitate when her doctors at Duke Health offered lecanemab as a treatment after she was diagnosed with early-stage Alzheimer’s disease at age 74.

Osmer has a family history of the disease. She had been active in retirement and didn’t notice significant problems at first, but imaging and genetic testing confirmed the diagnosis.

“When I got the diagnosis, it was pretty devastating,” said Osmer. “The prospect of having a slow decline but being physically healthy is very frightening. We were fortunate to catch it early, and I was pleased to begin treatment.”

Osmer began receiving lecanemab infusions at Duke within a month of her diagnosis and has now completed more than a year on the therapy. She has not experienced serious side effects.

“It’s been very uneventful in terms of side effects,” said Osmer.

She said the treatment has allowed her to remain engaged in daily life and focused on time with her family, including her two grandchildren.

“I have dealt with a lot of anxiety about my current life and the future,” said Osmer. “Being on lecanemab definitely gives me a sense of hope and a promise for a better future than we’ve assumed about Alzheimer’s in the past.”

While lecanemab does not cure Alzheimer’s disease or reverse symptoms, researchers say slowing progression can help patients like Osmer maintain independence longer and potentially reach milestones while new therapies continue to emerge.

“This is about buying time in a disease that takes it away,” Liu said. “And our real-world experience shows that with careful risk-benefit assessments, time can be gained by many patients.”

In addition to Liu, Doraiswamy and Whitson, study authors include Alexander Moghadam, Mohammad Alam, Michael Lutz, Amber Navarra, Sheng Luo, Laura Wang, Jeffrey R. Petrella, Richard O'Brien, Kim Johnson, Daniel Parker, Cynthia Beam, Michelle Sanfilippo, Heba Al-Sahlani, Sandra Cobb, and My Liu.

Liu's role was funded by the Ann B. Bussel Award and the Duke-UNC NIH award (P30 AG072958). One or more study authors also have relationships with various pharmaceutical companies, including the maker of lecanemab.