Elosulfase alfa contains an enzyme that occurs naturally in the body in healthy people. Some people lack this enzyme because of a genetic disorder. Elosulfase alfa helps replace this missing enzyme in such people.

Elosulfase alfa is used to treat some of the symptoms of a genetic condition called mucopolysaccharidosis (MYOO-koe-pol-ee-SAK-a-rye-DOE-sis) IV (4) type A, or MPS IV A, also called Morquio A syndrome.

MPS IVA is a metabolic disorder in which the body lacks the enzyme needed to break down certain natural substances. These substances can build up in the body, causing enlarged organs, abnormal bone structure, changes in facial features, breathing problems, heart problems, vision or hearing loss, and changes in mental or physical abilities.

Elosulfase alfa may improve walking and stair-climbing ability in people with this condition. However, this medication is not a cure for MPS IVA.

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

Your elosulfase alfa infusion may be delayed if you have a fever or cold symptoms.

Tell your doctor if you have ever had:

• breathing problems; or
• sleep apnea, and you use a continuous positive airway pressure (CPAP) machine.

Tell your doctor if you are pregnant or breastfeeding.

It is not known whether elosulfase alfa will harm an unborn baby. However, MPS symptoms can get worse during pregnancy and may cause medical problems in both mother and baby. The benefit of treating MPS may outweigh any risks to the baby.

Your name may need to be listed on a Morquio A Registry while you are using this medicine. The purpose of this registry is to track the progression of this disorder and the effects that elosulfase alfa has on long-term treatment of Morquio A syndrome. The registry also tracks the effects of elosulfase alfa on a baby if you are pregnant or breastfeeding.

Use Elosulfase Alfa (Intravenous) exactly as directed on the label, or as prescribed by your doctor. Do not use in larger or smaller amounts or for longer than recommended.

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

An allergic reaction may occur during or shortly after infusion of this medicine (up to 3 hours later). Tell your caregivers or get emergency medical help right away if you have any signs of a severe allergic reaction, such as:

• feeling like you might pass out, even while lying down;
• cough, chest discomfort, feeling short of breath;
• skin rash or redness, sudden warmth or tingly feeling;
• nausea, vomiting;
• pale skin; or
• blue lips or fingernails.

Common side effects of elosulfase alfa may include:

• nausea, vomiting, stomach pain;
• headache;
• fever, chills; or
• feeling tired.

Even though it may not be a side effect of elosulfase alfa, increased pressure on the spinal cord is a complication of MPS IVA that may occur while you are using this medicine. Tell your doctor right away if you have any symptoms of spinal cord compression:

• back pain;
• loss of movement in any part of your body; or
• loss of bowel or bladder control.

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.

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