This medication is used to treat nerve problems due to a certain inherited condition (transthyretin-mediated amyloidosis). This condition causes a protein that your body normally makes (transthyretin-TTR) to change shape and build up in different parts of your body, which can affect the nerves, heart, eyes, and stomach/intestines. This medication works by decreasing the buildup of TTR in your body.

Read the Patient Information Leaflet and Instructions for Use if available from your pharmacist before you start using eplontersen and each time you get a refill. Ask your health care professional how to prepare and use this medication. If you have any questions, ask your doctor or pharmacist.

Inject this medication under the skin as directed by your doctor, usually once a month. The injection is given in the upper arm, upper thigh, or abdomen.

Take the medication out of the refrigerator at least 30 minutes before you inject it to allow it to reach room temperature. Do not warm up this medication any other way (for example, do not heat it in the microwave or place it in hot water). Before using, check this product for particles or discoloration. If either is present, do not use the liquid. Before injecting each dose, clean the skin you are going to inject into (the injection site) with rubbing alcohol. Change the injection site each time to lessen injury under the skin. Do not inject into skin that is bruised, tender, red, hard, or tattooed, or into scars. To lessen bruising, do not rub the injection site after a shot. Learn how to store and discard medical supplies safely.

Use this medication regularly to get the most benefit from it. To help you remember, inject this medication on the same day each month.

Bruising, redness, itching, pain, or swelling at the injection site may occur. Vomiting may also occur. If any of these effects last or get worse, tell your doctor or pharmacist promptly.

Remember that this medication has been prescribed because your doctor has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.

This medication decreases vitamin A levels in your blood. Ask your doctor about taking a vitamin A supplement. Tell your doctor right away if you develop signs of a lack of vitamin A, especially vision changes such as dry eyes, blurred vision, or trouble seeing in dim light (night blindness).

A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including:

• rash
• itching/swelling (especially of the face/tongue/throat)
• severe dizziness
• trouble breathing

This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.

In the US - Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch.

In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.

Before using eplontersen, tell your doctor or pharmacist if you are allergic to it; or if you have any other allergies. This product may contain inactive ingredients which can cause allergic reactions or other problems. Talk to your pharmacist for more details.

Before using this medication, tell your doctor or pharmacist your medical history.

Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).

During pregnancy, this medication should be used only when clearly needed. Discuss the risks and benefits with your doctor.

It is unknown if this medication passes into breast milk. Consult your doctor before breastfeeding.

Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval.

If someone has overdosed and has serious symptoms such as passing out or trouble breathing, call 911. Otherwise, call a poison control center right away. US residents can call 1-800-222-1222. Canada residents can call 1-844-764-7669.

Do not share this medication with others.

Lab and/or medical tests may be done while you are using this medication. Keep all medical and lab appointments.

If you miss a dose, use it as soon as you remember. Keep using your next dose 1 month from the date of the last dose. Do not double the dose to catch up.

Store in the refrigerator. Do not freeze or expose to heat. Keep the medication in the original package to protect from light. This medication may also be stored at room temperature if needed. If the medication is stored at room temperature, discard after 6 weeks. Keep all medications away from children and pets.

Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company.