Nexviazyme helps replace an enzyme that is missing in people with a genetic disorder called late-onset Pompe disease, (also called GAA deficiency) in children at least 1 year old.

Nexviazyme may also be used for purposes not listed in this medication guide.

Tell your caregivers or get emergency medical help right away if you have any signs of a severe allergic reaction, such as itching, rash, redness or tingling, chest discomfort, wheezing, trouble breathing or swallowing, swelling in your face, pale skin, and blue lips or fingernails.

Avalglucosidase is injected into a vein by a healthcare provider, usually once every 2 weeks.

This medicine must be given slowly over 4 to 5 hours.

You may be given other medications to help prevent serious side effects or allergic reaction. Keep taking these medicines for as long as your doctor has prescribed.

Tell your doctor if you have ever had:

• heart disease; or

• lung disease or breathing problems.

Tell your doctor if you are pregnant or plan to become pregnant. Having untreated Pompe disease during pregnancy may increase your risk of worsened breathing problems and joint or muscle problems. The benefit of treating Pompe disease may outweigh any risks.

Ask a doctor if it is safe to breastfeed while using Nexviazyme.

Your name may be listed on the Pompe Registry. This is to track the progress of your disease and the outcome of your treatment with Nexviazyme.

Call your doctor for instructions if you miss an appointment for your Nexviazyme.

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

Follow your doctor's instructions about any restrictions on food, beverages, or activity.

Get emergency medical help if you have signs of an allergic reaction: hives, itching; difficult breathing; swelling of your face, lips, tongue, or throat.

Some reactions may occur during the injection, or within a few hours afterward. Tell your medical caregiver or get emergency medical help right away if you have:

• wheezing, cough, chest discomfort, trouble breathing;

• pale skin, blue lips or fingernails;

• swelling in your tongue;

• trouble swallowing;

• dizzines, nausea;

• rash; or

• flushing (sudden warmth, redness, or tingly feeling).

Tell your caregivers or get emergency medical help right away if you have any signs of a severe allergic reaction, such as itching, rash, redness or tingling, chest discomfort, wheezing, trouble breathing or swallowing, swelling in your face, pale skin, and blue lips or fingernails.

Common side effects of Nexviazyme may include:

• headache, dizziness, feeling tired;

• nausea, vomiting, diarrhea;

• itching, rash, redness;

• muscle or joint pain;

• trouble breathing; or

• numbness, tingling, burning pain.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.