Sacituzumab govitecan-hziy can cause severe or life-threatening decrease in the number of white blood cells in your blood. Your doctor will order laboratory tests regularly during your treatment to check the number of white blood cells in your blood. A decrease in the number of white blood cells in your body may increase the risk that you will develop a serious infection. If you experience any of the following symptoms, call your doctor immediately: fever, chills, sore throat, shortness of breath, ongoing cough, congestion, burning or pain when you urinate, or other signs of infection.

Sacituzumab govitecan-hziy can cause severe diarrhea. If you experience any of the following symptoms, call your doctor immediately: loose stools; diarrhea; black or bloody stools; signs of dehydration such as lightheadedness, dizziness, or faintness; or if you are unable to take fluids by mouth due to nausea or vomiting. Talk to your doctor about what you should do if you develop diarrhea at any time during your treatment with sacituzumab govitecan-hziy or if it is not controlled within 24 hours after treatment with medications for diarrhea.

Keep all appointments with your doctor and the laboratory. Your doctor will order certain tests before and during your treatment to check your body’s response to sacituzumab govitecan-hziy.

Talk to your doctor about the risks of receiving sacituzumab govitecan-hziy.

Sacituzumab govitecan-hziy is used to treat a certain type of breast cancer in adults that has spread to other parts of the body or cannot be removed by surgery and who have already been treated with at least two other chemotherapy medications. Sacituzumab govitecan-hziy is in a class of medications called antibody-drug conjugates. It works by killing cancer cells.

Sacituzumab govitecan-hziy comes as a powder to be mixed with liquid and injected intravenously (into a vein) over 1 to 3 hours by a doctor or nurse in a hospital or medical facility. It is usually given on days 1 and 8 of a 21-day cycle. The cycle may be repeated as recommended by your doctor. The length of your treatment depends on how well your body responds to the medication and any side effects that you experience.

Sacituzumab govitecan-hziy injection may cause nausea, vomiting, and serious allergic reactions, which usually occur during the infusion of the medication or within 24 hours of receiving a dose. You will be given other medications to help prevent and treat reactions. A doctor or nurse will watch you carefully during and for at least 30 minutes after the infusion for any reactions to the medication. If you experience any of the following symptoms, tell your doctor immediately: nausea; vomiting; swelling of your face, lips, tongue, or throat; fever; dizziness; flushing; chills; rash; hives; itching; wheezing; or difficulty breathing.

Your doctor may decrease your dose or temporarily or permanently stop 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 sacituzumab govitecan-hziy.

Ask your pharmacist or doctor for a copy of the manufacturer’s information for the patient.

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

Before receiving sacituzumab govitecan-hziy,

• Tell your doctor and pharmacist if you are allergic to sacituzumab govitecan-hziy, any other medications, or any of the ingredients in sacituzumab govitecan-hziy injection. Ask your pharmacist 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. Be sure to mention any of the following: carbamazepine (Carbatrol, Equetro, Teril, others), atazanavir (Reyataz, in Evotaz), indinavir (Crixivan), irinotecan (Camptosar, Onivyde), phenobarbital, rifampin (Rifadin, in Rifater), and sorafenib (Nexavar). 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 liver disease.
• Tell your doctor if you are pregnant, plan to become pregnant, or if you plan to father a child. You or your partner should not become pregnant while you are receiving sacituzumab govitecan-hziy injection. If you are a woman who is able to become pregnant, you must take a pregnancy test before starting treatment and use effective birth control during your treatment and for 6 months after your final dose. If you are male, you and your female partner should use birth control during your treatment and for 3 months after your final dose. Talk to your doctor about birth control methods that will work for you. If you or your partner becomes pregnant while receiving sacituzumab govitecan-hziy injection, call your doctor. Sacituzumab govitecan-hziy may harm the fetus.
• Tell your doctor if you are breastfeeding. You should not breastfeed while you are receiving sacituzumab govitecan-hziy and for 1 month after your final dose.
• You should know that this medication may decrease fertility in women. Talk to your doctor about the risks of receiving sacituzumab govitecan-hziy.

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

If you miss an appointment to receive sacituzumab govitecan-hziy, call your doctor right away.

Sacituzumab govitecan-hziy may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:

• Constipation
• Mouth sores
• Stomach pain
• Tiredness
• Loss of appetite
• Taste changes
• Hair loss
• Dry skin
• Headache
• Pain, burning, or tingling in the hands or feet
• Back or joint pain
• Pain in arms or legs
• Swelling of the hands, ankles, or feet
• Difficulty falling asleep or staying asleep
• Pale skin or unusual tiredness or weakness

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

• Easy bruising or bleeding; bleeding from gums or nose; or blood in urine or stool

Sacituzumab govitecan-hziy 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).

In case of overdose, call the poison control helpline at 1-800-222-1222. Information is also available online at https://www.poisonhelp.org/help. If the victim has collapsed, had a seizure, has trouble breathing, or can’t be awakened, immediately call emergency services at 911.

Symptoms of overdose may include:

• Fever, chills, cough, or other signs of infection

Ask your pharmacist any questions you have about sacituzumab govitecan-hziy. Your doctor may order certain lab tests before you begin your treatment to see if you may be more likely to have an increased risk for side effects from sacituzumab govitecan-hziy based on your heredity or genetic make-up.

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.