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Screen for hepatitis B virus in all cancer patients starting systemic treatment. Find out more about hepatitis B virus screening and management.

tebentafusp

( te-BEN-ta-fusp )
Other Name(s): Kimmtrak®
Appearance: yellowish solution, mixed into larger bags of fluids

tebentafusp

Pronunciation:

te-BEN-ta-fusp

Other Name(s):

Kimmtrak®

Appearance:

yellowish solution, mixed into larger bags of fluids

This handout gives general information about this cancer medication.

You will learn:

  • who to contact for help

  • what the medication is

  • how it is given

  • what to expect while on medication

People Talking

This handout was created by Ontario Health (Cancer Care Ontario) together with patients and their caregivers who have also gone through cancer treatment. It is meant to help support you through your cancer treatment and answer some of your questions.

This information does not replace the advice of your health care team. Always talk to your health care team about your treatment.

 

Who do I contact if I have questions or need help?

 

My cancer health care provider is: _____________________________________________

During the day I should contact: _______________________________________________

Evenings, weekends and holidays: _____________________________________________

 

This page gives general information about this cancer medication.

You will learn:

  • who to contact for help

  • what the medication is

  • how it is given

  • what to expect while on this medication

People Talking

This information was created by Ontario Health (Cancer Care Ontario) together with patients and their caregivers who have also gone through cancer treatment. It is meant to help support you through your cancer treatment and answer some of your questions.

This information does not replace the advice of your health care team. Always talk to your health care team about your treatment.

What is this treatment for?
What should I do before I start this treatment?

Tell your health care team if you have or had significant medical condition(s), especially if you have / had: 

  • heart problems
  • adrenal gland problems (such as Addison's disease)
  • any allergies
     
Important Icon

Remember To:

 
  • Tell your health care team about all of the other medications you are taking.

  • Keep taking other medications that have been prescribed for you, unless you have been told not to by your health care team.

You will have a blood test to check for hepatitis B before starting treatment. See the Hepatitis B and Cancer Medications pamphlet for more information.

How is this treatment given?
  • This drug is given through an IV (injected into a vein) . 
  • You may be admitted to hospital when you get your first treatments so that your health care team can monitor how your body reacts. Your health care team may give you medications before your treatments to help prevent side effects.

  • Your tebentafusp infusion will be given according to a step-up schedule (also known as ramp-up) for the first 3 doses. This means that your doses will start off smaller and will be increased over time so that your health care team can make sure you do not have any problems with the medication. Talk to your health care team about your treatment schedule.

  • If you miss your treatment appointment, talk to your health care team to find out what to do.
Other medications you may be given with this treatment

To Prevent or Treat Nausea and Vomiting

You may be given medications to prevent or stop nausea (feeling like throwing up) and vomiting (throwing up) before they start. These are called anti-nausea medications.

  • Medications to prevent nausea and vomiting before they start include ondansetron (Zofran®), granisetron (Kytril®), dexamethasone or others.

If you already have nausea and/or vomiting, some anti-nausea medications can stop them from getting worse. You may be given these medications to have at home in case you start to feel nausea or if you vomit.

  • Medications to stop nausea and vomiting include prochlorperazine (Stemetil®), metoclopramide (Maxeran®), or others.

 

 

Other important things for you to know about this treatment

Tebentafusp causes your immune system to work harder. Your immune system is what fights infections and your cancer.

When your immune system is working harder, it can also damage healthy cells. This can cause side effects that are different from other cancer medications, like chemotherapy.

 

Cytokine release syndrome (CRS) can happen when your immune system responds aggressively to tebentafusp. CRS usually happens during the ramp up schedule and with your first full dose. The symptoms can be mild but can also quickly become severe and life-threatening.

CRS can be treated. It is important to catch it early so that the treatment has the best chance of working well. Talk to your healthcare team right away if you have any of the following signs of CRS:

  • Fever higher than 38°C
  • Trouble breathing
  • Fast or irregular heartbeat
  • Flu-like symptoms (such as chills, body aches and fatigue)
  • Severe nausea, vomiting or diarrhea

 

Ask your health care team for the Treating cancer with T-cell engaging antibodies: What you need to know pamphlet for more information.

 

You will be given a wallet card that has information and instructions for other health care providers about your treatment and possible side-effects. Show this card to all health care providers, especially if you need to go to the emergency room. 

 

DO this while on treatment
  • DO check with your health care team before getting any vaccinations, surgery, dental work or other medical procedures.
     
  • DO consider asking someone to drive you to and from the hospital on your treatment days. You may feel drowsy or dizzy after your treatment.
     
  • DO tell your health care team if you have an adrenal insufficiency (such as Addison's disease). Your health care team may need to adjust your corticosteroid dose during your tebentafusp treatment.
DO NOT do this while on treatment

Stop Icon

  • DO NOT smoke or drink alcohol while on treatment without talking to your health care team first. Smoking and drinking can make side effects worse and make your treatment not work as well.
     
  • DO NOT take any other medications, such as vitamins, over-the-counter (non-prescription) drugs or substances, or natural health products without checking with your health care team.
     
  • DO NOT start any complementary or alternative therapies, such as acupuncture or homeopathic medications, without checking with your health care team.

DO this while on treatment

Check Mark Icon

  • DO check with your health care team before getting any vaccinations, surgery, dental work or other medical procedures.
     
  • DO consider asking someone to drive you to and from the hospital on your treatment days. You may feel drowsy or dizzy after your treatment.
     
  • DO tell your health care team if you have an adrenal insufficiency (such as Addison's disease). Your health care team may need to adjust your corticosteroid dose during your tebentafusp treatment.
DO NOT do this while on treatment

Stop Icon

  • DO NOT smoke or drink alcohol while on treatment without talking to your health care team first. Smoking and drinking can make side effects worse and make your treatment not work as well.
     
  • DO NOT take any other medications, such as vitamins, over-the-counter (non-prescription) drugs or substances, or natural health products without checking with your health care team.
     
  • DO NOT start any complementary or alternative therapies, such as acupuncture or homeopathic medications, without checking with your health care team.

Will this treatment interact with other medications or natural health products?
  • Yes, this medication can interact with other medications, vitamins, foods, traditional medicines and natural health products. Interactions can make this medication not work as well or cause severe side effects.
    • Tell your health care team about all of your:
      • prescription and over-the-counter (non-prescription) medications
      • other drugs and substances, such as cannabis/marijuana (medical or recreational)
      • natural health products such as vitamins, herbal teas, homeopathic medicines, and other supplements, or traditional medicines
    • Check with your health care team before starting or stopping any of them.

 

  • If you are taking a blood thinner (such as warfarin), your health care team may need extra blood tests and may change your dose.
     
  • If you take medications to help with your blood pressure, your health care team may ask you to stop these medications 24 hours before and during your treatment.

 

Medication Icon
Talk to your health care team BEFORE taking or using these :
  • Anti-inflammatory medications such as ibuprofen (Advil® or Motrin®), naproxen (Aleve®) or Aspirin®.
  • Over-the-counter products such as dimenhydrinate (Gravol®
  • Natural health products such as St. John’s Wort
  • Traditional medicines
  • Supplements such as vitamin C
  • Grapefruit juice
  • Alcoholic drinks 
  • Tobacco 
  • All other drugs or substances, such as marijuana or cannabis (medical or recreational)
What to do if you feel unwell, have pain, a headache or a fever
  • Always check your temperature to see if you have a fever before taking any medications for fever or pain (such as acetaminophen (Tylenol®) or ibuprofen (Advil®)).

    • Fever can be a sign of infection or CRS that may need treatment right away.

    • If you take these medications before you check for fever, they may lower your temperature and you may not know you have an infection or CRS.

How to check for fever:

Keep a digital (electronic) thermometer at home and take your temperature if you feel hot or unwell (for example, chills, headache, mild pain). 

  • You have a fever if your temperature taken in your mouth (oral temperature) is:

    • 38.0°C (100.4°F) or higher.

Medication Icon

If you do have a fever: 

 

 

 

 


 

If you do not have a fever but have mild symptoms such as headache or mild pain:

  • Ask your health care team about the right medication for you. Acetaminophen (Tylenol®) is a safe choice for most people.
Stop Icon

Talk to your health care team before you start taking ibuprofen (Advil®, Motrin®), naproxen (Aleve®) or ASA (Aspirin®), as they may increase your chance of bleeding or interact with your cancer treatment.

Important Icon

Talk to your health care team if you already take low dose aspirin for a medical condition (such as a heart problem). It may still be safe to take.

How will this treatment affect sex, pregnancy and breastfeeding?

Talk to your health care team about:

  • How this medication may affect your sexual health.

  • How this medication may affect your ability to have a baby, if this applies to you.

This medication may harm an unborn baby. Tell your health care team if you or your partner are pregnant, become pregnant during treatment, or are breastfeeding.

  • If there is any chance of pregnancy happening, you and your partner together must use 2 effective forms of birth control at the same time until at least one week after your last dose. Talk to your health care team about which birth control options are best for you.
     

  • Do not breastfeed while on this medication and for at least one week after your last dose.

 

What are the side effects of this treatment?

The following table lists side effects that you may have when getting tebentafusp treatment. The table is set up to list the most common side effects first and the least common last. It is unlikely that you will have all of the side effects listed and you may have some that are not listed.

Read over the side effect table so that you know what to look for and when to get help. Refer to this table if you experience any side effects while on tebentafusp treatment.

Some side effects can become serious or life-threatening very quickly. You must tell your health care team right away if:

  • You start to have any new side effects, especially if severe.
  • You notice any of your side effects getting worse.

 


Very Common Side Effects (50 or more out of 100 people)
Side effects and what to do When to contact health care team

Cytokine release syndrome

(may be severe)

Cytokine release syndrome (CRS) can happen when your immune system responds aggressively to tebentafusp. This can cause the release of a large amount of proteins called cytokines.

CRS usually happens at the start of treatment, when your immune system starts to work harder (within hours and up to a few days of getting your first 3 doses).

Symptoms of CRS can be mild but can also quickly become severe and life-threatening. Your health care team will monitor you more closely during and for a few days after your first 3 doses, and do blood tests as necessary.

What to look for?

  • Fever. Sometimes the fever can be high (more than 40ºC).
  •  You may also have:
    • Trouble breathing
    • Fast or irregular heartbeats 
    • Flu-like symptoms (such as chills, body aches and fatigue) 
    • Severe nausea, vomiting or diarrhea
    • Signs of low blood pressure, such as dizziness 

What to do?

  • Tell your nurse right away if you have any signs of CRS during or just after your treatment. Symptoms may get worse quickly.

If you have left the hospital:

  • Check your temperature to see if you have a fever. If you have a fever, or any other signs of CRS, try to contact your health care team. If you cannot speak to the team for advice, you MUST get emergency medical help right away.
  • If you get emergency medical help, make sure you show the emergency health care team the wallet card given to you by your cancer health care team.

 

Talk to your health care team. If you are unable to talk to the team for advice, you must get emergency medical help right away.

Rash; dry, itchy skin

(May be severe)

What to look for?

  • You may have cracked, rough, flaking or peeling areas of the skin.
  • Your skin may look red and feel warm, like a sunburn.
  • Your skin may itch, burn, sting or feel very tender when touched.

What to do?

To prevent and treat dry skin:

  • Use fragrance-free skin moisturizer.
  • Protect your skin from the sun and the cold.
  • Use sunscreen with UVA and UVB protection and a SPF of at least 30.
  • Avoid perfumed products and lotions that contain alcohol.
  • Drink 6 to 8 cups of non-alcoholic, non-caffeinated liquids each day, unless your health care team has told you to drink more or less.

Rash may be severe in some rare cases and cause your skin to blister or peel. If this happens, get emergency medical help right away.

 

 

Talk to your health care team if it does not improve or if it is severe

Fever, chills

You have a fever if your temperature taken in your mouth (oral temperature) is:

  • 38.0°C (100.4°F) or higher.

What to look for?

  • If you feel hot or unwell (for example if you have chills or a new cough), you must check your temperature to see if you have a fever.
  • Do not take medications that treat a fever before you take your temperature (for example, Tylenol® (acetaminophen), or Advil® (ibuprofen)).
  • Do not eat or drink anything hot or cold right before taking your temperature
  • You may have fever, chills and muscle pain without any signs of infection, such as a sore throat, cough or skin rash.
  • It may happen at any time after you receive your treatment and it usually goes away as your body gets used to the medication.


What to do?

If your health care team has told you that you have low neutrophils:

  • Wash your hands often to prevent infection.
  • Check with your health care team before getting any vaccines, surgeries, medical procedures or visiting your dentist.
  • Keep a digital thermometer at home so you can easily check for a fever.

If you have a fever:

If you have a fever, try to contact your health care team. If you are unable to talk to the team for advice, you must get emergency medical help right away.

 

If you have a fever, try to contact your health care team. If you are unable to talk to the team for advice, you MUST get emergency medical help right away.

Fatigue 

What to look for?

  • Feeling of tiredness or low energy that lasts a long time and does not go away with rest or sleep.
     

What to do?

  • Be active. Aim to get 30 minutes of moderate exercise (you are able to talk comfortably while exercising) on most days.
  • Check with your health care team before starting any new exercise.
  • Pace yourself, do not rush. Put off less important activities. Rest when you need to.
  • Ask family or friends to help you with things like housework, shopping, and child or pet care.
  • Eat well and drink at least 6 to 8 glasses of water or other liquids every day (unless your health care team has told you to drink more or less).
  • Avoid driving or using machinery if you are feeling tired.

Ask your health care team for the Fatigue pamphlet for more information. 

Talk to your health care team if it does not improve or if it is severe

 

Common Side Effects (25 to 49 out of 100 people)
Side effects and what to do When to contact health care team

Nausea and vomiting

(Generally mild)

What to look for?

  • Nausea is feeling like you need to throw up. You may also feel light-headed.
  • You may feel nausea within hours to days after your treatment.

 

What to do?

To help prevent nausea:

  • It is easier to prevent nausea than to treat it once it happens.
  • If you were given anti-nausea medication(s), take them as prescribed, even if you do not feel like throwing up.
  • Drink clear liquids and have small meals. Get fresh air and rest.
  • Do not eat spicy, fried foods or foods with a strong smell.
  • Limit caffeine (like coffee, tea) and avoid alcohol.


If you have nausea or vomiting:

  • Take your rescue (as-needed) anti-nausea medication(s) as prescribed.
  • Ask your health care team for the Nausea & Vomiting pamphlet for more information.
  • Talk to your health care team if:
    • nausea lasts more than 48 hours
    • vomiting lasts more than 24 hours or if it is severe
Talk to your healthcare team if nausea lasts more than 48 hours or vomiting lasts more than 24 hours or if it is severe

Changes in skin or hair colour

This may happen weeks or months after your tebentafusp treatment.

What to look for?

  • The colour of your hair, eyelashes or eyebrows may change (get lighter or darker)
  • Your skin may get darker or lighter in certain areas. This may appear patchy.

What to do?

  • Protecting your skin from the sun may help prevent skin problems. Use sunscreen with UVA and UVB protection and a SPF of at least 30.
  • Tell your health care team if this bothers you. Some skin colour changes may slowly go back to normal once you stop your treatment.

 

 

Talk to your health care team if it does not improve or if it is severe

Mild swelling

What to look for?

  • You may have mild swelling or puffiness in your arms and/or legs. Rarely, this may be severe.
     

What to do?

To help prevent swelling:

  • Eat a low-salt diet.


If you have swelling:

  • Wear loose-fitting clothing.
  • For swollen legs or feet, keep your feet up when sitting.

 

 

Talk to your health care team if it does not improve or if it is severe

Low blood pressure

What to look for?

  • You may feel tired, dizzy or light-headed.
  • You may have nausea (feeling like you need to throw up), vomiting or blurred vision.
  • You may faint (pass out).
  • It may happen during or shortly after your treatment is given to you and may be severe.
     

What to do?

  • Tell your nurse right away if this happens during or shortly after your infusion. Your health care team may need to give you fluids or medication to increase your blood pressure. 
  • If this happens after you have left the hospital, check your blood pressure often. Talk to your health care team about what to do if it doesn't improve.
  • If you feel dizzy or unwell sit or lay down right away so that you do not fall. Try to get up and move slowly only once you feel better.
  • Do not drive a motor vehicle or operate machinery if you feel dizzy.

 

 

 

Talk to your health care team if it does not improve or if it is severe

Mild Headache, joint, muscle pain or cramps 

What to look for?

  • New headache, pain in your muscles or joints, muscle cramps, or feeling achy.

What to do?

  • Take pain medication (such as acetaminophen) as needed.
  • Read the above section: "What should I do if I feel unwell, have pain, a headache or a fever?" before taking acetaminophen (Tylenol®), ibuprofen (Advil®, Motrin®), naproxen (Aleve®) or Aspirin. These medications may hide an infection that needs treatment or they may increase your risk of bleeding.

Ask your health care team for the Pain pamphlet for more information.

If you have a sudden, severe headache get emergency medical help right away.

Talk to your health care team if it does not improve or if it is severe

Diarrhea

What to look for?

  • Loose, watery, unformed stool (poo) that may happen days to weeks after you get your treatment.
     

What to do?

If you have diarrhea:

  • Take anti-diarrhea medication if your health care team prescribed it or told you to take it.
  • Do not eat foods or drinks with artificial sweetener (like chewing gum or ‘diet’ drinks), coffee and alcohol, until your diarrhea has stopped.
  • Eat many small meals and snacks instead of 2 or 3 large meals.
  • Drink at least 6 to 8 cups of liquids each day, unless your health care team has told you to drink more or less.
  • Talk to your health care team if you can’t drink 6 to 8 cups of liquids each day when you have diarrhea. You may need to drink special liquids with salt and sugar, called Oral Rehydration Therapy.
  • Talk to your health care team if your diarrhea does not improve after 24 hours of taking diarrhea medication or if you have diarrhea more than 7 times in one day.


Ask your health care team for the Diarrhea pamphlet for more information.

Talk to your health care team if no improvement after 24 hours of taking diarrhea medication or if severe (more than 7 times in one day)

 

Less Common Side Effects (10 to 24 out of 100 people)
Side effects and what to do When to contact health care team

Liver problems

Your health care team may check your liver function with a blood test. Liver changes do not usually cause any symptoms.


What to look for?

  • Rarely, you may develop yellowish skin or eyes, unusually dark pee or pain on the right side of your belly. This may be severe.


What to do?

If you have any symptoms of liver problems, get emergency medical help right away.

 

 

Get emergency medical help right away

Low appetite

What to look for?

  • Loss of interest in food or not feeling hungry.
  • Weight loss.


What to do?

  • Try to eat your favourite foods.
  • Eat small meals throughout the day.
  • You may need to take meal supplements to help keep your weight up.
  • Talk to your health care team if you have no appetite.

Ask your health care team for the Loss of Appetite pamphlet for more information.

 

 

 

 

Talk to your health care team if it does not improve or if it is severe

Constipation

What to look for?

  • Having bowel movements (going poo) less often than normal.
  • Small hard stools (poo) that look like pellets.
  • The need to push hard and strain to have any stool (poo) come out.
  • Stomach ache or cramps.
  • A bloated belly, feeling of fullness, or discomfort.
  • Leaking of watery stools (poo).
  • Lots of gas or burping.
  • Nausea or vomiting.
     

What to do?

To help prevent constipation:

  • Try to eat more fiber rich foods like fruits with skin, leafy greens and whole grains.
  • Drink at least 6 to 8 cups of liquids each day unless your health care team has told you to drink more or less.
  • Be Active. Exercise can help to keep you regular.
  • If you take opioid pain medication, ask your health care team if eating more fibre is right for you.
     

To help treat constipation:

  • If you have not had a bowel movement in 2 to 3 days you may need to take a laxative (medication to help you poo) to help you have regular bowel movements. Ask your health care team what to do.

Ask your health care team for the Constipation Pamphlet for more information.

 

 

 

 

 

 

Talk to your health care team if it does not improve or if it is severe

Cough and feeling short of breath

What to look for?

  • You may have a cough and feel short of breath.
  • Symptoms that commonly occur with a cough are:
    • wheezing or a whistling breathing
    • runny nose
    • sore throat
    • heartburn
    • weight loss
    • fever and chills
  • Rarely this may be severe with chest pain, trouble breathing or coughing up blood.
     

What to do?

  • Check your temperature to see if you have a fever. Read the above section "What should I do if I feel unwell, have pain, a headache or a fever?".
  • If you have a fever, try to talk to your health care team. If you are not able to talk to them for advice, you MUST get emergency medical help right away.
  • If you have a severe cough with chest pain, trouble breathing or you are coughing up blood, get medical help right away.
Talk to your health care team. If you are not able to talk to your health care team for advice, and you have a fever or severe symptoms, you MUST get emergency medical help right away

High blood pressure

What to look for?

  • There are usually no signs of high blood pressure.
  • Rarely, you may have headaches, shortness of breath or nosebleeds.
     

What to do?

  • Check your blood pressure regularly.
  • Your doctor may prescribe medication to treat high blood pressure.

If you have a severe headache get emergency help right away as it may be a sign your blood pressure is too high.

Talk to your health care team if it does not improve or if it is severe

Anemia (low red blood cells)

What to look for?

  • You may feel more tired or weaker than normal.
  • Pale skin and cold hands and feet.
  • You may feel short of breath, dizzy or lightheaded.
  • This may occur in days to weeks after your treatment starts.
     

What to do?

If your health care team has told you that you have anemia (low red blood cells):

  • Rest often and eat well.
  • Light exercise, such as walking may help.
  • You may need medication or a blood transfusion.
  • If it is very bad, your doctor may need to make changes to your treatment regimen.
Talk to your health care team if it does not improve or if it is severe

Other rare, but serious side effects are possible.
If you experience ANY of the following, speak to your cancer health care provider or get emergency medical help right away:

  • Irregular or fast heartbeat, shortness of breath, chest pain or fainting spells

For more information on how to manage your symptoms ask your health care provider, or visit: https://www.cancercareontario.ca/symptoms.

Notes

August 2025 Updated patient medication information sheet

The information set out in the medication information sheets, regimen information sheets, and symptom management information (for patients) contained in the Drug Formulary (the "Formulary") is intended to be used by health professionals and patients for informational purposes only. The information is not intended to cover all possible uses, directions, precautions, drug interactions or side effects of a certain drug, nor should it be used to indicate that use of a particular drug is safe, appropriate or effective for a given condition.

A patient should always consult a healthcare provider if he/she has any questions regarding the information set out in the Formulary. The information in the Formulary is not intended to act as or replace medical advice and should not be relied upon in any such regard. All uses of the Formulary are subject to clinical judgment and actual prescribing patterns may not follow the information provided in the Formulary.