While there are many types of dementia, Alzheimer’s disease is by far the most common. According to the Alzheimer’s Association, approximately 6.7 million Americans have Alzheimer’s disease, as of 2023. In Alzheimer’s disease, plaques form in the brain and tend to affect people at any age. Symptoms usually get worse over time.
The U.S. Food and Drug Administration has approved new medications to treat mild or early dementia due to Alzheimer’s disease. These medications are called monoclonal antibodies (one example is Lecanemab though others are being considered for approval as well) and are infused directly into the blood. Injectable forms are being developed.
At present, Mount Sinai is offering the monocloncal antibody Lecanemab to eligible patients.
How It Works
Monoclonal antibodies work by clearing the plaques from your brain. These plaques are usually made up of a protein called amyloid. We’re not sure whether the plaques cause dementia, but we know they play a significant role.
Recent studies showed that monoclonal antibodies can slow the decline of symptoms such as forgetfulness and problems with day-to-day function. Patients who received the monoclonal antibody Lecanemab experienced an average of six-month slower decline in their symptoms than those who didn’t. The Lecanemab study followed patients for 18 months, and we do not know yet what happens after that point.
Side Effects
Monocloncal antibodies can cause side effects in some patients. The most serious is swelling or bleeding in the brain, which affects about 20 percent of patients receiving Lecanemab (one in five). Most patients with these symptoms don’t feel anything and we can find it only with a magnetic resonance imaging (MRI) scan. At some point in treatment, some patients may experience:
- Confusion
- Difficulty walking
- Dizziness
- Headaches
- Nausea
- Vision changes
- Seizures
- Inability to speak
- Loss of movement in an arm or leg
About 25 percent of patients (1 in 4) develop infusion-related reactions when receiving Lecanemab. Most of these reactions presented as mild flu-like symptoms, such as chills, body aches, joint pain and/or feeling shaky, nausea, vomiting, or dizziness or lightheadedness. In a smaller number of patients, infusion-related reactions are more severe, such as changes in heart rate, blood pressure or difficulty breathing. Rarely, patients with an infusion-related reaction had to be hospitalized because of severe allergic reactions.