Lecanemab

Lecanemab (Leqembi) is used for Alzheimer’s disease to help slow the progression of dementia in patients who have mild cognitive impairment (MCI) or mild dementia symptoms. Lecanemab works by reducing amyloid beta (Aβ) plaques and protofibrils in the brain, which helps slow down the worsening of dementia symptoms and may help people manage their daily lives and live independently for longer.

Lecanemab can be started either as an intravenous (IV) infusion given every 2 weeks, which takes about 1 hour, or as a once-weekly injection under the skin (subcutaneous injection) using the Leqembi Iqlik (pronounced "I Click") autoinjector. After 18 months of treatment, patients may continue on their starting dose or move to a maintenance dose, which can be given by IV infusion or subcutaneous injection.

In a clinical trial (Clarity AD), Lecanemab was effective in reducing cognitive decline by 27% over 18 months compared to those who received a placebo. It helps control Alzheimer’s disease but does not cure it.

Alzheimer's disease is a type of dementia that affects memory, thinking, and behavior, and it can eventually grow severe enough to interfere with daily tasks. One of the causes of Alzheimer's disease is thought to be an abnormal buildup of amyloid beta in the brain as plaques and protofibrils (a toxic clumped form of Aβ). This makes it harder for brain cells to communicate with each other and results in the symptoms of Alzheimer's disease.

Lecanemab works against amyloid beta in two related ways:

• Binds clumped amyloid beta: Lecanemab attaches to aggregated (clumped) forms of amyloid beta, including both soluble clumps and the insoluble deposits found in plaques.
• Helps reduce plaques: By binding these clumped forms, lecanemab helps the body clear amyloid and lower the amount of plaque in the brain.

Reducing amyloid beta plaque is how lecanemab helps slow the decline in memory, thinking, and behavior in Alzheimer's disease.

Lecanemab's mechanism of action is as an amyloid beta-directed antibody against aggregated soluble and insoluble forms of amyloid beta.

Lecanemab approval is to treat Alzheimer's disease in patients who have:

• mild cognitive impairment or mild dementia due to Alzheimer's disease, and
• presence of amyloid beta pathology.

Lecanemab (Leqembi) FDA approval was granted on January 6, 2023, to Eisai Inc.

Do not receive this medicine if you are allergic to the active ingredient lecanemab or any of the inactive ingredients in this medicine. See below for a list of inactive ingredients.

Tell your healthcare provider about all of your medical conditions, including if you:

• are pregnant or intending to become pregnant
• are breastfeeding or intending to breastfeed.

Pregnancy

It is not known if this medicine will harm your unborn baby. Tell your healthcare provider if you become pregnant during lecanemab treatment.

Breastfeeding

It is not known if lecanemab passes into breast milk. Talk to your healthcare provider about the best way to feed your baby while receiving this medicine.

Common lecanemab side effects

The most common side effects of lecanemab infusion are:

• infusion-related reactions, which can be serious
• headache
• swelling in areas of the brain, with or without small bleeding spots in or on the brain's surface (ARIA).

Infusion-related reactions. Infusion-related reactions occurred in 26% of lecanemab patients compared to 7% of placebo patients. Symptoms of infusion reactions are:

• fever
• flu-like symptoms (chills, generalized aches, feeling shaky, and joint pain),
• nausea and vomiting,
• low blood pressure (hypotension),
• high blood pressure (hypertension),
• and oxygen desaturation.

Managing infusion-related reactions. If you have an infusion-related reaction the infusion rate may be reduced, or the infusion may be stopped, and appropriate therapy may be started as clinically indicated. Before future infusions, preventative (prophylactic) treatment with antihistamines, acetaminophen, nonsteroidal anti-inflammatory drugs, or corticosteroids may be considered.

Injection-related reactions. If you receive lecanemab as an injection under the skin (subcutaneous injection with Leqembi Iqlik), you may have a reaction at the injection site. This can include redness (erythema), a hard lump or firmness (induration), swelling, warmth, rash, pain, itching, bruising (ecchymosis), and a collection of blood under the skin (hematoma). Some people may also have symptoms such as headache, chills, fever, and tiredness (fatigue). Tell your healthcare provider if you have any of these reactions during or after your injection.

The most common side effects occurred in 10% or more of patients and were higher than the side effect incidence compared to placebo.

Serious lecanemab side effects and warnings

Lecanemab carries a Boxed Warning for Amyloid-related imaging abnormalities (ARIA).

Amyloid Related Imaging Abnormalities or "ARIA". This medicine can cause a condition called ARIA, which usually occurs early in treatment and does not usually cause any symptoms, but serious symptoms can occur and can be fatal. ARIA is most commonly seen as temporary swelling in areas of the brain that usually resolves over time. Some people may also have small spots of bleeding in or on the surface of the brain, and infrequently, larger areas of bleeding in the brain can occur. Most people with this type of swelling in the brain do not get symptoms; however, some people may have symptoms, such as headache, confusion, dizziness, vision changes, nausea, difficulty walking, or seizures. Call your healthcare provider or go to the nearest hospital emergency room right away if you have any of the symptoms listed above.

Some people have a genetic risk factor (homozygous apolipoprotein E gene carriers) that may cause an increased risk for ARIA. Talk to your healthcare provider about testing to see if you have this risk factor.

Some medicines can increase the risk for larger areas of bleeding in the brain in patients taking this medicine. Talk to your healthcare provider to see if you are on any medicines that increase this risk.

Your healthcare provider will do magnetic resonance imaging (MRI) scans before and during your treatment with this medicine to check you for ARIA. Call your healthcare provider or go to the nearest hospital emergency room right away if you have any of the symptoms listed above.

You should carry information that you are receiving this medicine, which can cause ARIA, and that ARIA symptoms can look like stroke symptoms.

Serious allergic reactions. Swelling of the face, lips, mouth, or tongue, hives, or difficulty breathing has happened during treatment with lecanemab. Tell your healthcare provider and get medical help right away if you have any symptoms of a serious allergic reaction during or after treatment with lecanemab.

Infusion-related reactions. Infusion-related reactions are a common side effect that can be serious.

These are not all the possible side effects of lecanemab. For more information, ask your healthcare provider or pharmacist, or see the below for more detailed information on side effects. Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.

Lecanemab (Leqembi) cost will depend on your insurance coverage and Leqembi Copay eligibility. For links to enrollment forms for the Copay Cards and Patient Assistance Program (PAP) see the Leqembi Prices, Coupons, Copay Cards, and Patient Assistance page.

Lecanemab can be given as an intravenous (IV) infusion or as an injection under the skin (subcutaneous injection), depending on which formulation you are prescribed.

Lecanemab infusion

• Lecanemab IV infusion is given by your healthcare provider through a needle placed in a vein in your arm.
• Infusions are given every 2 weeks during the starting dose period. After 18 months, infusions may change to every 4 weeks.Each infusion will last about 1 hour.
• You may receive medications before your infusion, such as antihistamines, anti-inflammatories, or steroids, to reduce your risk of having an infusion-related reaction. Tell your healthcare provider right away if you get symptoms of an infusion-related reaction. See infusion-related reaction symptoms in the side effects section.

Subcutaneous lecanemab (Leqembi Iqlik)

• Lecanemab can also be given as a once-weekly injection under the skin using the Leqembi Iqlik autoinjector, either as a starting dose or as a maintenance dose after 18 months.
• Leqembi Iqlik is injected into the front of the thighs or the stomach area (abdomen), except for the 2-inch area around the belly button. A healthcare provider or caregiver may also inject into the back of the upper arm. Do not inject into moles, scars, bruises, tattoos, or into areas where the skin is red, hard, tender, or injured. Use a different injection site at least 1 inch away from the last site each time.
• You or a caregiver can give the injection once your healthcare provider decides you are ready. This happens after you have received at least 2 doses in a row under their direct guidance, and once your provider decides it is appropriate.
• Your healthcare provider will show you how to prepare and give the injection and tell you how often to use it. Always use it exactly as directed.
• If you miss a dose of Leqembi Iqlik, inject the missed dose as soon as possible up to 6 days after the missed dose. Continue your next injection on your regularly scheduled day.

The recommended starting dose of lecanemab depends on how it is given:

• Intravenous (IV) infusion: 10 mg/kg once every 2 weeks. The dose is diluted first and then infused into a vein over approximately 1 hour.
• Subcutaneous injection: 500 mg once a week, given as two 250 mg injections, using the Leqembi Iqlik autoinjector.
• After 18 months of treatment, you may continue on the starting dose or move to a maintenance dose, which can be given intravenously or subcutaneously.

The recommended maintenance dose is:

• Intravenous (IV) infusion: 10 mg/kg once every 4 weeks.
• Subcutaneous injection: 360 mg once a week using the Leqembi Iqlik autoinjector.

Lecanemab is available as:

Leqembi 200 mg/2 mL (100 mg/mL) in a single-dose vial for intravenous infusionLeqembi 500 mg/5 mL (100 mg/mL) in a single-dose vial for intravenous infusionLeqembi Iqlik 250 mg/1.25 mL (200 mg/mL) in a single-dose prefilled autoinjector for subcutaneous injectionLeqembi Iqlik 360 mg/1.8 mL (200 mg/mL) in a single-dose prefilled autoinjector for subcutaneous injection

Review the Leqembi Package Insert (PI) for more detailed information about this medicine. The PI contains more comprehensive information on Indications and Usage, Dosage and Administration, Clinical Pharmacology, Clinical Studies, Drug Interaction, and more. Discuss any medical questions you have with your doctor or other health care provider. This is not all the information you need to know about this medicine for safe and effective use, and it does not take the place of talking to your doctor about your treatment.

The Package Insert is sometimes called the Prescribing Information (PI) or the FDA label.

Tell your doctor and pharmacist what prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking or plan to take. Your doctor may need to change the doses of your medications or monitor you carefully for side effects.

Especially tell your healthcare provider if you take medicines to reduce blood clots from forming (antithrombotic medicines, including aspirin). Ask your healthcare provider for a list of these medicines if you are not sure.

Know the medicines you take. Keep a list of them to show your healthcare provider and pharmacist when you get a new medicine.

Unopened Vial Storage:

• Store in a refrigerator at 2°C to 8°C (36°F to 46°F).
• Store in the original carton to protect from light.
• Do not freeze or shake.

After vial dilution

• Immediate use is recommended
• If not administered immediately, store refrigerated at 2°C to 8°C (36°F to 46°F) for up to 4 hours, or at room temperature up to 30°C (86°F) for up to 4 hours.
• Do not freeze.

Manufactured by: Eisai Inc. Nutley, NJ 07110

LEQEMBI® is a registered trademark of Eisai R&D Management Co., Ltd.

LEQEMBI IQLIK® is a registered trademark of Eisai R&D Management Co., Ltd. © 202X Eisai Inc. and Biogen

Active ingredient: lecanemab-irmb.Inactive ingredients: arginine hydrochloride, histidine, histidine hydrochloride monohydrate, polysorbate 80, and water for injection.