Efgartigimod alfa is used to treat a certain muscle condition (generalized myasthenia gravis). It may help to improve symptoms of muscle weakness.

This medication is also used to treat a certain nerve disorder (chronic inflammatory demyelinating polyneuropathy-CIDP). Efgartigimod alfa may help slow down the worsening of weakness in the arms and legs.

Hyaluronidase is used to help the body absorb efgartigimod alfa, which helps it work better.

This monograph is about the following efgartigimod/hyaluronidase products: efgartigimod-fcab/hyaluronidase, efgartigimod-qvfc/hyaluronidase.

Read the Patient Information Leaflet and Instructions for Use if available from your pharmacist before you start using this medication and each time you get a refill. If you have any questions, ask your doctor or pharmacist.

If you are using this medication at home, learn all preparation and usage instructions from your health care professional and the product package.

Inject this medication under the skin as directed by your doctor, usually once weekly. The injection is given in the abdomen (except for a 2-inch area around your belly button). Additional treatment cycles are given based on your medical condition and response to treatment.

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, place it in hot water, or leave it in direct sunlight). Do not shake the medication. 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 tender, bruised, red, hard, or damaged. To lessen bruising, do not rub the injection site after a shot. Learn how to store and discard medical supplies safely.

Injection reactions or serious allergic reactions may happen during the injection and for a short time afterward. Tell your doctor right away if you have any symptoms of injection reactions such as high blood pressure, chills, shivering, stomach pain, or back/chest pain. Your doctor may give you other medications to help with these side effects or may slow down your injection. Monitor for an allergic reaction for at least 30 minutes after each injection and get medical help right away if you notice any symptoms of a serious allergic reaction (see also Side Effects section).

Use this medication regularly to get the most benefit from it. To help you remember, mark your calendar with a reminder.

Tell your doctor if your condition gets worse.

See also How to Use section.

Headache or injection site reactions (such as redness, pain, bruising, itching, swelling) may 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 may lower your ability to fight infections. This may make you more likely to get a serious infection or make any infection you have worse. Tell your doctor right away if you have any signs of infection (such as sore throat that doesn't go away, fever, chills, painful/burning urination).

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 this product, tell your doctor or pharmacist if you are allergic to efgartigimod alfa or hyaluronidase; or to any efgartigimod products; 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, especially of:

• current/recent infection

Efgartigimod alfa can make you more likely to get infections or may make current infections worse. Stay away from anyone who has an infection that may easily spread (such as chickenpox, COVID-19, measles, flu). Talk to your doctor if you have been exposed to an infection or for more details.

Tell your health care professional that you are using this product before having any immunizations/vaccinations. Avoid contact with people who have recently received live vaccines (such as flu vaccine inhaled through the nose).

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. Mothers who have used this medication during pregnancy should ask a doctor about immunizations/vaccinations for their newborn babies.

It is unknown if this drug 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.

Lab and/or medical tests (such as complete blood count) should be done while you are using this medication. Keep all medical and lab appointments. Consult your doctor for more details.

It is important to get each dose of this medication as scheduled. If you miss a dose, ask your doctor or pharmacist right away for a new dosing schedule.

Store in the refrigerator. Do not freeze. Do not use this medication if it has been frozen. Keep the medication in the original carton to protect from light. This medication may also be stored at room temperature if needed. If the medication is stored at room temperature, do not put it back in the refrigerator and discard after 30 days. 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.

Your condition can cause complications in a medical emergency. For information about enrolling in MedicAlert, call 1-888-633-4298 (US) or 1-800-668-1507 (Canada).