This medication is used to treat a certain type of cancer (uveal melanoma). Tebentafusp belongs to a class of drugs known as monoclonal antibodies. It works by slowing or stopping the growth of cancer cells.

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

This medication is given by injection into a vein as directed by your doctor, usually once a week. The injection is given by a health care professional, usually over 15 to 20 minutes. The dosage is based on your medical condition and response to treatment. To reduce your risk of side effects, your doctor may prescribe other medications (such as dexamethasone) before each treatment to help reduce side effects. Also, your doctor may start this medication at a low dose and gradually increase your dose.

See also Warning section.

Dry/itchy skin, loss of color in the skin, hair color changes, swelling ankles/feet/hands, or muscle/joint pain may occur. If any of these effects last or get worse, tell your doctor or pharmacist promptly.

People using this medication may have serious side effects. However, you have been prescribed this drug because your doctor has judged that the benefit to you is greater than the risk of side effects. Careful monitoring by your doctor may decrease your risk.

Tell your doctor right away if you have any serious side effects, including:

• signs of liver problems (such as nausea/vomiting that doesn't stop, loss of appetite, stomach/abdominal pain, yellowing eyes/skin, dark urine)

Tebentafusp can commonly cause skin redness, itching, swelling, or a rash that are usually not serious. However, you may not be able to tell it apart from a rare rash that could be a sign of a severe reaction. Tell your doctor right away if you develop any rash.

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 tebentafusp, tell your doctor or pharmacist if you are allergic to it; 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.

This drug may make you dizzy. Alcohol or marijuana (cannabis) can make you more dizzy. Do not drive, use machinery, or do anything that needs alertness until you can do it safely. Limit alcoholic beverages. Talk to your doctor if you are using marijuana (cannabis).

Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).

Tell your doctor if you are pregnant or plan to become pregnant. You should not become pregnant while using tebentafusp. Tebentafusp may harm an unborn baby. Your doctor should order a pregnancy test before you start this medication. Ask about reliable forms of birth control while using this medication and for 1 week after the last dose. If you become pregnant, talk to your doctor right away about the risks and benefits of this medication.

It is unknown if this drug passes into breast milk. Because of the possible risk to the infant, breastfeeding is not recommended while using this drug and for at least 1 week after the last dose. 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, liver function) should be done while you are using this medication. Keep all medical and lab appointments.

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.

Not applicable. This medication is given in a hospital or clinic and will not be stored at home.