Leqembi (Lecanemab-irmb): Understanding Side Effects and Management

Alzheimer's disease is a progressive neurodegenerative disorder that affects millions worldwide, impacting memory, thinking, and behaviour. While there is no cure, advancements in treatment offer hope for managing symptoms and potentially slowing disease progression. One such medication is Leqembi (lecanemab-irmb), a prescription drug approved for adults with Alzheimer's disease. Leqembi is administered either as an intravenous (IV) infusion or as a subcutaneous injection (Leqembi Iqlik). Understanding its potential side effects is crucial for patients and their caregivers to ensure safe and effective treatment.

What is Leqembi?
Leqembi is a monoclonal antibody that targets amyloid plaques, a hallmark of Alzheimer's disease. By binding to these plaques, it aims to help clear them from the brain, potentially slowing cognitive decline. It's important to note that Leqembi is not a cure for Alzheimer's disease, but rather a treatment option to manage its progression.

Understanding Leqembi Side Effects

Like all medications, Leqembi can cause side effects. These can range from mild to serious. The Food and Drug Administration (FDA) has issued a boxed warning for Leqembi, highlighting the most serious potential risks. It is essential to discuss these risks thoroughly with your doctor before starting treatment.

Common Side Effects

Some of the more frequently reported side effects of Leqembi include:

• Infusion Reactions (for IV Leqembi): These can occur during or shortly after the infusion. Symptoms may include fever, chills, headache, dizziness, nausea, or changes in blood pressure.
• Injection Site Reactions (for Leqembi Iqlik): These are localized reactions at the injection site and may include redness, swelling, pain, itching, or hardening of the skin.
• Headache: A common side effect that is usually mild and manageable.

These common side effects are often temporary and may resolve on their own. However, if they persist, worsen, or become bothersome, it is important to consult your doctor.

Serious Side Effects: ARIA

The most significant concern with Leqembi is the risk of Amyloid-Related Imaging Abnormalities (ARIA). ARIA is a condition that can involve temporary swelling (ARIA-E) or microhemorrhages (ARIA-H) in the brain. While often asymptomatic, ARIA can sometimes lead to serious neurological symptoms.

Symptoms of ARIA may include:

• Severe headache
• Confusion
• Dizziness or loss of balance
• Vision changes (blurred vision, double vision)
• Difficulty speaking or understanding speech
• Nausea or vomiting
• Seizures

Factors that can increase the risk of ARIA include:

• Having two copies of a gene called APOE ε4. This genetic factor is known to increase the risk of developing Alzheimer's disease and may also increase the risk of ARIA with certain treatments.
• Taking other medications that affect blood clotting.

Due to the risk of ARIA, regular monitoring with MRI scans is essential for individuals receiving Leqembi treatment. Your doctor will use these scans to detect any signs of ARIA and assess its severity.

Allergic Reactions

Although rare, severe allergic reactions to Leqembi can occur. Symptoms of a severe allergic reaction include:

• Swelling of the face, lips, tongue, or throat
• Difficulty breathing or shortness of breath
• Hives or rash
• Dizziness or fainting

If you experience any signs of a severe allergic reaction, seek immediate medical attention by calling 911 or your local emergency number.

When to Consult a Doctor

It is crucial to maintain open communication with your healthcare provider throughout your treatment with Leqembi. You should contact your doctor immediately if you experience any of the following:

• Symptoms of ARIA, such as severe headache, confusion, vision changes, or seizures.
• Signs of a severe allergic reaction.
• Any side effects that are severe, persistent, or worsening.
• Concerns about the medication or its potential impact on your health.

Your doctor will monitor your condition closely, adjust treatment as needed, and provide guidance on managing any side effects.

Managing Side Effects

Managing Leqembi side effects involves a collaborative approach between the patient, caregiver, and healthcare team.

• For Infusion Reactions: Your doctor may slow down the infusion rate, administer medications to manage symptoms (like fever reducers or antihistamines), or temporarily pause the infusion.
• For Injection Site Reactions: Applying a cool compress, keeping the area clean, and avoiding tight clothing can help. Your doctor might also suggest topical creams if needed.
• For Headaches: Over-the-counter pain relievers, as recommended by your doctor, can help manage mild headaches.
• For ARIA: If ARIA is detected, your doctor may temporarily stop or permanently discontinue Leqembi treatment. Depending on the severity, other interventions might be necessary.

It is vital not to stop Leqembi treatment without consulting your doctor, as this could affect the overall efficacy of the therapy.

Long-Term Safety and Considerations

Leqembi is a relatively new drug, approved by the FDA in 2023. While studies have provided valuable information on its safety and efficacy up to 18 months of treatment, long-term side effects are still being studied. Therefore, ongoing monitoring and reporting of any unusual symptoms are essential.

Before starting Leqembi, ensure your doctor is aware of your complete medical history, including any genetic predispositions (like APOE ε4 status), other medical conditions, and all medications you are currently taking. This information is vital for assessing potential risks and developing a personalized treatment plan.

In conclusion, Leqembi offers a promising therapeutic option for individuals with Alzheimer's disease. However, like all medications, it carries potential risks. By understanding the common and serious side effects, particularly ARIA, and maintaining close communication with your healthcare provider, patients can navigate treatment safely and effectively. Regular monitoring and prompt reporting of any concerning symptoms are key to managing Leqembi therapy and optimizing outcomes.