BY PAM MCGRATH

New drugs known as anti-amyloid immunotherapies are now available to treat some people in the early stages of Alzheimer’s disease. Administered to slow the progression of the disease, these drugs are the first to successfully treat the underlying cause of Alzheimer’s.

“A hallmark of Alzheimer’s disease is the buildup of amyloid plaques in the brain, which may interfere with memory and thinking,” says B. Joy Snider, MD, PhD, WashU Medicine neurologist at Barnes-Jewish Hospital and director of the WashU Medicine Memory Diagnostic Center. “Until now, the drugs approved to treat Alzheimer’s were developed to help with symptoms of the disease. These new anti-amyloid immunotherapies remove amyloid plaques from the brain,” Dr. Snider adds. She also notes that while these drugs do not cure Alzheimer’s or improve memory and thinking, clinical trials have shown they slow progression of the disease by about 30% when administered in the early stages of the disease.

“Alzheimer’s has a 10- to 20-year preclinical stage, during which amyloid plaques and neurofibrillary tau tangles—another hallmark of the disease—are silently accumulating,” says Suzanne Schindler, MD, PhD, WashU Medicine neurologist at Barnes-Jewish Hospital and clinician at the Memory Diagnostic Center. “Patients are asymptomatic during this time.”

When symptoms do begin, they can progress from mild but consistent cognitive issues— repeating questions, forgetting appointments, having difficulty with speech and writing—to mild dementia, when the tasks of everyday life become increasingly difficult. As the disease progresses to the moderate stage, people can no longer live alone; when it becomes severe, people are completely dependent on others for the basic activities of life. “About 15% to 20% of all people with Alzheimer’s disease have mild problems with memory and thinking,” says Dr. Snider. “These are the people who are candidates for this new treatment.”

Treatment at the Memory Diagnostic Center is administered by experts in the field. WashU Medicine physician-researchers were involved in a study evaluating one of the new drugs, and many of those same physicians have also used the drugs to care for patients. When evaluating someone for treatment, specialists first determine an individual’s eligibility for anti-amyloid immunotherapies by conducting patient and family interviews, cognitive tests, neurological exams, bloodwork, and structural brain imaging. They also look for factors other than Alzheimer’s that may cause problems with memory and thinking, including some medications, sleep apnea, and depression. If symptoms suggest Alzheimer’s, additional tests might include an amyloid PET scan or an amyloid blood test to confirm the diagnosis.

Treatment is administered through intravenous (IV) infusion with one of two available antiamyloid immunotherapies: lecanemab (Leqembi) or donanemab (Kisunla). For lecanemab, infusions are given every two weeks; for donanemab, once a month. For both drugs, the treatment period lasts at least 18 months. Infusion treatments are available at Barnes-Jewish Hospital, as well as at other BJC HealthCare community hospitals.

According to a study by researchers at WashU Medicine, treatment with this new generation of drug can help a person with Alzheimer’s disease gain 10 to 13 months of independent living. In this study, the researchers calculated the benefits of treatment using data on the natural history of the disease and the magnitude of the drugs’ effects as measured in clinical trials. The type of drug used and the severity of the patient’s symptoms at the time treatment began help determine those benefits. As a representative example, a typical person who started treatment with very mild symptoms could expect to live independently for an additional 13 months if treated with lecanemab, or eight months with donanemab.

Side effects from treatment can include flu-like symptoms that usually are mild and decrease over time. “About 20% of people also develop a complication called amyloid-related imaging abnormalities; most often, this is mild and asymptomatic,” says Dr. Schindler. These abnormalities are detectable on brain scans and represent tiny spots of blood in the brain or localized swelling of the brain. Most of the time, there are no symptoms, and the abnormalities resolve on their own, but a minority are more serious; in rare instances, deaths have been linked to this side effect. Dr. Schindler notes: “Throughout treatment, we work to ensure patient safety using regularly scheduled MRIs and clinic visits.”

Learn more about a new WashU Medicine study involving an anti-amyloid drug that shows signs of preventing Alzheimer’s disease.