Not for everyone

Lecanemab is not helpful for people with no symptoms of cognitive decline or those in later stages of Alzheimer's disease. The medicine does not prevent or cure AD. Your healthcare team helps you decide if lecanemab is an option for you.

The medicines you take for other conditions and your health history may affect whether you can take lecanemab. If you have a history of cancer or bleeding in your brain or use anticlotting medicines, such as warfarin (Jantoven) or apixaban (Eliquis), you might not be able to take lecanemab.

Also, people who carry a certain form of a gene known as APOE e4 appear to have a higher risk of serious side effects, such as severe ARIA, when they take lecanemab. The U.S. Food and Drug Administration recommends being tested for this gene before starting treatment with lecanemab.

If you take lecanemab, you also need a brain MRI before beginning treatment. Then you have regular MRI scans to check for brain swelling and bleeding. Getting scanned during the first months of treatment is important. This is when ARIA is most likely to happen.