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zolbetuximab

( ZOL-beh-TUK-sih-mab )

Other Name(s): Vyloy®

Appearance: mixed into larger bags of fluids

zolbetuximab patient.pdf

zolbetuximab

Pronunciation:

ZOL-beh-TUK-sih-mab

Other Name(s):

Vyloy®

Appearance:

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

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?

Zolbetuximab is used to treat certain types of stomach cancers.

It is usually given with other medications.

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:

kidney or liver problems
recent nausea and/or vomiting
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 given through an IV (injected into a vein). Talk to your health care team about your treatment schedule.

If you missed 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 Nausea and Vomiting

You will be given medications to help prevent nausea (feeling like throwing up) and vomiting (throwing up) before they start.

These are called anti-nausea medications and include medications such as ondansetron (Zofran®), granisetron (Kytril®), aprepitant (Emend®), olanzapine (Zyprexa®), or others.

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 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 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 products, 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 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 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 NOT do this while on treatment

Stop Icon

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 products, 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.

Will this treatment interact with other medications or natural health products?

Although this medication is unlikely to interact with other medications, vitamins, foods, traditional medicines and natural health products, 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 6 months (general recommendation) after your last treatment dose. Talk to your health care team about which birth control options are best for you.

Do not breastfeed while on this treatment and for 8 months after your last dose.

What are the side effects of this treatment?

The following table lists side effects that you may have when getting zolbetuximab treatment. Some of these side effects may also be from other chemotherapy that is given with zolbetuximab. 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 zolbetuximab treatment.

Very Common Side Effects (50 or more out of 100 people)
Nausea and vomiting (May be severe) 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

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

Side effects and what to do

When to contact health care team

Nausea and vomiting
(May be severe)

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

Common Side Effects (25 to 49 out of 100 people)
Side effects and what to do	When to contact health care team
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 neutrophils (white blood cells) in the blood (neutropenia) (May be severe) When neutrophils are low, you are at risk of getting an infection more easily. Ask your health care team for the Neutropenia (Low white blood cell count) pamphlet for more information. 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 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. 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.
Allergic reaction (May be severe) What to look for? Itchiness, rash, swollen lips, face or tongue, chest and throat tightness. 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 you feel any signs of allergic reaction during or just after your treatment. Talk to your health care team for advice if you have a mild skin reaction.	Get emergency medical help right away for severe symptoms
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

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
Too little salt in your body (May be severe) What to look for? Muscle spasms, cramping, weakness, twitching, or convulsions. Irregular heartbeat, confusion or blood pressure changes. What to do? Get emergency medical help right away for severe symptoms.	Get emergency medical help right away for severe symptoms
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 levels of albumin in your blood (May be severe) Albumin is a protein that is found in the blood. It helps to maintain pressure in the blood vessels and move substances, such as hormones and medications through your body. Your health care team may check your levels of albumin with a blood test. Low albumin may not cause any symptoms unless your level is very low. What to look for? Fatigue (feeling tired) Muscle weakness or cramps Loss of appetite Swelling in your ankles or legs Swelling in your belly (if you also have liver problems) What to do? If you have any of these symptoms, talk to your health care team. If you have swelling in your belly, get emergency medical help right away.	If you have any of these symptoms, talk to your health care team. If you have swelling in your belly, get emergency medical help right 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
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

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:

New cough, breathing problems, chest pain or coughing up blood.
Pain, swelling and hardening of the vein in an arm or leg
Bleeding from your gums, unusual nosebleeds, bruising easily or more than normal, or blood in your urine (pee) or stools (poo). If you have bleeding that doesn’t stop or is very heavy, you must get emergency help.

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

Notes

September 2025 New drug 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.

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