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belzutifan

( bell ZOO ti fan )

Other Name(s): Welireg®

Appearance: tablet

belzutifan patient.pdf

belzutifan

Pronunciation:

bell ZOO ti fan

Other Name(s):

Welireg®

Appearance:

tablet

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

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

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?

Belzutifan is used to treat certain types of kidney or pancreatic cancers.

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:

lung or heart problems
low levels of oxygen in your blood
low levels of red blood cells (anemia) or
any allergies.

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 medication is usually taken once a day by mouth. Talk to your health care team about how and when to take your medication.
Swallow the tablets whole with a full glass of water, with or without food.
Do not crush, chew, or split belzutifan tablets.
If you forget to take a dose, take the missed dose as soon as possible on the same day. Then, take your next dose as scheduled on the next day. Do not take extra (double up) to make up for the forgotten dose.
If you vomit (throw up) after taking your medication, do not retake the dose. The next dose should be taken on the next day.

Warning: If you take too much of this medication by accident, or if you think a child or a pet may have swallowed your medication, you must call the Ontario Poison Control Center right away at: 1-800-268-9017.

DO this while on treatment

DO check with your health care team before getting any vaccinations, surgery, dental work or other medical procedures.

DO NOT do this while on treatment

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DO NOT take any other medications, such as vitamins, over-the-counter (non-prescription) drugs, 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 NOT use tobacco products (such as smoking cigarettes or vaping) 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 drive, operate machinery or do any tasks that need you to be alert if you feel dizzy.

DO this while on treatment

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DO check with your health care team before getting any vaccinations, surgery, dental work or other medical procedures.

DO NOT do this while on treatment

Stop Icon

DO NOT take any other medications, such as vitamins, over-the-counter (non-prescription) drugs, 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 NOT use tobacco products (such as smoking cigarettes or vaping) 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 drive, operate machinery or do any tasks that need you to be alert if you feel dizzy.

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.

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 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.

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:
- 38.3°C (100.9°F) or higher at any time
OR
- 38.0°C (100.4°F) or higher for at least one hour.

If you do have a fever :

Try to contact your health care team. If you are not able to talk to them for advice, you MUST get emergency medical help right away.
Ask your health care team for the Fever pamphlet for more information.

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.

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.

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 treatment may affect your sexual health
How this treatment may affect your ability to have a baby, if this applies to you

This treatment 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 1 week after your last treatment dose. Talk to your health care team about which birth control options are best for you.

This treatment may make hormonal birth control, such as birth control pills, less effective (not work as well). Talk to your health care team about the best birth control options for you.

Do not breastfeed while on this treatment and for at least 1 week after your last dose.

How to safely store and handle this medication

Keep belzutifan tablets in the original packaging at room temperature in a dry place, away from heat and light.

Keep out of sight and reach of children and pets.

Do not throw out any unused belzutifan tablets at home. Bring them to your pharmacy to be thrown away safely.

How to safely touch oral anti-cancer medication

If you are a patient:

Wash your hands before and after touching your oral anti-cancer medication.
Swallow each pill whole. Do not crush or chew your pills.

If you are a caregiver:

Wear nitrile or latex gloves when touching tablets, capsules or liquids.
Wash your hands before putting on your gloves and after taking them off, even if your skin did not touch the oral anti-cancer medication.
Throw out your gloves after each use. Do not re-use gloves.
Do not touch oral anti-cancer medications if you are pregnant or breastfeeding.

What to do if anti-cancer medication gets on your skin or in your eyes

If medication gets on your skin:

Wash your skin with a lot of soap and water.
If your skin gets red or irritated, talk to your health care team.

If medication gets in your eyes:

Rinse your eyes with running water right away. Keep water flowing over your open eyes for at least 15 minutes.

What are the side effects of this treatment?

The following table lists side effects that you may have when getting belzutifan. 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 belzutifan.

Very Common Side Effects (50 or more out of 100 people)
Anemia (low red blood cells) (May be severe) 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.

Very Common Side Effects (50 or more out of 100 people)

Side effects and what to do

When to contact health care team

Anemia (low red blood cells)

(May be severe)

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.

Common Side Effects (25 to 49 out of 100 people)
Side effects and what to do	When to contact health care team
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.
Mild joint, muscle pain or cramps, or headaches What to look for? New pain in your muscles or joints, muscle cramps, or feeling achy. Mild headaches What to do? Take pain medication (acetaminophen or opioids such as codeine, morphine, hydromorphone, oxycodone) as prescribed. Read the above section: "What to do if you 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. Rest often and try light exercise (such as walking) as it may help. Ask your health care team for the Pain pamphlet for more information.	Talk to your health care team if it does not improve or if it is severe.

Less Common Side Effects (10 to 24 out of 100 people)
Side effects and what to do	When to contact health care team
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.
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	Contact your healthcare team if nausea lasts more than 48 hours or vomiting lasts more than 24 hours.
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 to do if you 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.
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.
Low levels of oxygen in the body (hypoxia) (May be severe) Your health care team will monitor your oxygen levels regularly. In some cases, your health care team may ask you to check your oxygen levels at home using an oximeter (a small, clip-like device commonly attached to the tip of your finger). Talk to your health care team to understand what oxygen levels are normal for you and what levels may be too low. What to look for? Symptom that commonly occur include: Feeling short of breath Rapid breathing Chest pain Dizziness Ringing in the ears What to do? If you have any symptoms of low oxygen levels, try to talk to your health care team. Get emergency medical help right away: If you are not able to speak to your health care team. If you experience confusion that will not go away. This could be a sign of severe hypoxia.	Get emergency medical help right away if you are not able to speak to your health care team, or If you experience confusion that will not go away.
Dizziness What to look for? You may feel light-headed and like you might faint (pass out). What to do? Lay down right away so you do not fall. Slowly get up and start moving once you feel better. Do not drive a motor vehicle or use machinery if you feel dizzy.	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).
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.
Bleeding; Low platelets in the blood (May be severe) When platelets are low, you are at risk for bleeding and bruising. Ask your health care team for the Low Platelet Count pamphlet for more information. What to look for? Watch for signs of bleeding: bleeding from your gums unusual or heavy nosebleeds bruising easily or more than normal black coloured stools (poo) or blood in your stools (poo) coughing up red or brown coloured mucus dizziness, constant headache or changes in your vision heavy vaginal bleeding red or pink coloured urine (pee) What to do? If your health care team has told you that you have low platelets: Tell your pharmacist that your platelet count may be low before taking any prescriptions or over-the-counter medication. Check with your healthcare team before you go to the dentist. Take care of your mouth and use a soft toothbrush. Try to prevent cuts and bruises. Ask your health care team what activities are safe for you. If you have signs of bleeding: If you have a small bleed, clean the area with soap and water or a saline (saltwater) rinse. Apply pressure for at least 10 minutes. If you have bleeding that does not stop or is severe (very heavy), you must get emergency medical help right away.	Talk to your health care team if you have any signs of bleeding. If you have bleeding that doesn’t stop or is severe, you MUST get emergency medical help right away.

Other rare, but serious side effects are possible with this treatment.

If you have any of the following, talk to your cancer health care team or get emergency medical help right away:

eyes that feel dry, irritated, painful, sensitive to light or blurry vision
pain, swelling and hardening of a vein

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

Notes

June 2025 New patient 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.

belzutifan

Funding & Reimbursement

Symptom Management

Drug Safety and Administration