Lecanemab-irmb injection is used to treat Alzheimer's disease (a brain disorder that affects the ability to remember, think clearly, communicate, and perform daily activities and may cause changes in mood and personality) in patients with mild disease. Lecanemab-irmb is in a class of medications called monoclonal antibodies. It works by reducing amyloid beta plaques, abnormal proteins that develop in the brain and contribute to the progression of Alzheimer's disease.

Lecanemab-irmb injection comes as a solution (liquid) to be infused intravenously by a doctor or nurse in a healthcare setting. It is usually given every 2 weeks in an infusion that lasts about an hour.

Lecanemab-irmb injection may cause a severe reaction during or shortly after the infusion of the medication. A doctor or nurse will monitor you carefully while you are receiving the medication. If you experience any of the following symptoms, tell your doctor immediately: fever, chills, body aches, joint pain, nausea, vomiting, dizziness or lightheadedness, feeling of racing heart rate or chest pounding, or difficulty breathing or shortness of breath.

Lecanemab-irmb controls Alzheimer's disease but does not cure it. Do not stop receiving lecanemab-irmb without talking to your doctor.

Before receiving lecanemab-irmb injection,

• tell your doctor and pharmacist if you are allergic to lecanemab-irmb, any other medications, or any of the ingredients in lecanemab-irmb injection. Ask your pharmacist or check the Medication Guide for a list of the ingredients.
• tell your doctor and pharmacist what prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking or plan to take while taking lecanemab-irmb. Your doctor may need to change the doses of your medications or monitor you carefully for side effects.
• tell your doctor if you are pregnant, plan to become pregnant, or are breast-feeding. If you become pregnant while taking lecanemab-irmb, call your doctor.

Unless your doctor tells you otherwise, continue your normal diet.

Lecanemab-irmb injection may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:

• headache

Some side effects can be serious. If you experience any of these symptoms, call your doctor immediately:

• confusion
• visual changes
• dizziness
• nausea
• difficulty walking or loss of balance
• seizures

Lecanemab-irmb may cause other side effects. Call your doctor if you have any unusual problems while taking this medication.

If you experience a serious side effect, you or your doctor may send a report to the Food and Drug Administration's (FDA) MedWatch Adverse Event Reporting program online (http://www.fda.gov/Safety/MedWatch) or by phone (1-800-332-1088).

This medication may be prescribed for other uses; ask your doctor or pharmacist for more information.

Keep all appointments with your doctor. If you miss a scheduled infusion appointment, call your doctor to reschedule as soon as possible.

It is important for you to keep a written list of all of the prescription and nonprescription (over-the-counter) medicines you are taking, as well as any products such as vitamins, minerals, or other dietary supplements. You should bring this list with you each time you visit a doctor or if you are admitted to a hospital. It is also important information to carry with you in case of emergencies.