Naxitamab-gqgk injection may cause serious or life-threatening reactions. A doctor or nurse will watch you or your child closely while receiving the infusion and for at least 2 hours afterwards to provide treatment in case of a serious reaction to the medication. You may be given other medications before and during naxitamab-gqgk to prevent or manage infusion reactions. Tell your doctor immediately if you experience any of the following symptoms during your infusion or after your infusion: hives; rash; itching; reddening of the skin; fever; chills; wheezing or difficulty breathing or swallowing; swelling of the face, throat, tongue, or lips; dizziness, lightheadedness, or fainting; or a fast heartbeat.

Naxitamab-gqgk injection can cause damage to nerves that may result in pain or other symptoms. You or your child may receive pain medication before, during, and after the naxitamab-gqgk infusion. Tell your doctor or other health care provider(s) immediately if you or your child experience any of the following symptoms during and after the infusion: severe or worsening pain, particularly in the stomach, back, chest, muscles or joints; numbness, tingling, burning, or weakness in the feet or hands; difficulty urinating or emptying your bladder; bowel problems; headache; blurred vision, vision changes, larger pupil size, difficulty focusing, or sensitivity to light; confusion or decreased alertness; difficulty speaking; or seizures.

Your doctor or pharmacist will give you the manufacturer’s patient information sheet (Medication Guide) when you begin treatment with naxitamab-gqgk and each time you refill your prescription. Read the information carefully and ask your doctor or pharmacist if you have any questions. You can also visit the Food and Drug Administration (FDA) website (http://www.fda.gov/Drugs/DrugSafety/ucm085729.htm) or the manufacturer’s website to obtain the Medication Guide.

Talk to your doctor about the risk(s) of receiving naxitamab-gqgk injection.

Naxitamab-gqgk injection is used in combination with another medication in adults and children 1 year of age and older to treat neuroblastoma (a cancer that begins in nerve cells) in the bone or bone marrow that has returned or that did not respond to a previous treatment, but who have responded to other treatments. Naxitamab-gqgk injection is in a class of medications called monoclonal antibodies. It works by killing cancer cells.

Naxitamab-gqgk comes as a solution (liquid) to be injected intravenously (into a vein) over 30 to 60 minutes by a doctor or nurse in a medical facility or infusion center. It is usually given on days 1, 3, and 5 of a 28 day treatment cycle and it may be repeated based on your response. After the initial treatment, your doctor may prescribe additional treatment cycles every 8 weeks.

Your doctor will probably treat you with other medications before and during each dose to help prevent certain side effects. Your doctor may need to temporarily or permanently stop your treatment or decrease your dose of naxitamab-gqgk during your treatment. This depends on how well the medication works for you and the side effects you experience. Be sure to tell your doctor how you are feeling during your treatment with naxitamab-gqgk.

This medication may be prescribed for other uses; ask your doctor or pharmacist for more information.

Before receiving naxitamab-gqgk injection,

• tell your doctor and pharmacist if you are allergic to naxitamab-gqgk, any other medications, or any of the ingredients in naxitamab-gqgk injection. Ask your pharmacist or check the Medication Guide for a list of the ingredients.
• tell your doctor and pharmacist what other prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking or plan to take. Your doctor may need to change the doses of your medications or monitor you carefully for side effects.
• tell your doctor if you have or have ever had hypertension (high blood pressure); hypotension (low blood pressure); urinary retention (sudden inability to urinate); hypoglycemia (low blood sugar); a low number of red or white blood cells; a low number of platelets (blood clotting cells) in your blood; low blood levels of potassium, calcium, sodium, magnesium, phosphate, or albumin; or heart or liver disease.
• tell your doctor if you are pregnant or plan to become pregnant. You must take a pregnancy test before starting treatment. You should use effective birth control during your treatment and for 2 months after your final dose. If you become pregnant while receiving naxitamab-gqgk, call your doctor. Naxitamab-gqgk may harm the fetus.
• tell your doctor if you are breastfeeding. You should not breastfeed during your treatment with naxitamab-gqgk and for 2 months after your final dose.
• if you are having surgery, including dental surgery, tell the doctor or dentist that you are receiving naxitamab-gqgk injection.
• you should know that naxitamab-gqgk may cause very low blood pressure resulting in dizziness, lightheadedness, and fainting when you get up too quickly from sitting or a lying position. To avoid this problem, get out of bed slowly, resting your feet on the floor for a few minutes before standing up. If you have any of the following symptoms, call your doctor immediately and lie down: lightheadedness, fainting, or dizziness.

Unless your doctor tells you otherwise, continue your normal diet.

If you miss an appointment to receive naxitamab-gqgk injection, call your doctor as soon as possible.

Naxitamab-gqgk injection may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:

• vomiting
• nausea
• diarrhea
• loss of appetite
• anxiety
• irritability
• tiredness
• cough, runny nose, fever, or other signs of infection
• swelling of the arms, hands, feet, or lower legs

Some side effects can be serious. If you experience any of these symptoms or those listed in the IMPORTANT WARNING section, call your doctor immediately or get emergency medical treatment:

• severe headache, racing or irregular heartbeat, chest pain, dizziness, shortness of breath, or nose bleeds

Naxitamab-gqgk injection may cause other side effects. Call your doctor if you have any unusual problems while receiving this medication.

If you experience a serious side effect, you or your doctor may send a report to the Food and Drug Administration’s (FDA) MedWatch Adverse Event Reporting program online (http://www.fda.gov/Safety/MedWatch) or by phone (1-800-332-1088).

Keep all appointments with your doctor and the laboratory. Your doctor will check your blood pressure at certain times in your treatment cycle and order certain tests to check your body’s response to naxitamab-gqgk injection.

It is important for you to keep a written list of all of the prescription and nonprescription (over-the-counter) medicines you are taking, as well as any products such as vitamins, minerals, or other dietary supplements. You should bring this list with you each time you visit a doctor or if you are admitted to a hospital. It is also important information to carry with you in case of emergencies.

• Danyelza^®