Pronunciation: vye-LOY
Generic name: zolbetuximab-clzb
Dosage form: injection (100 mg lyophilized powder in a single-dose vial.)
Drug class: Miscellaneous antineoplastics

Medically reviewed by Melisa Puckey, BPharm. Last updated on Oct 30, 2024.

What is Vyloy?

Vyloy (zolbetuximab) is a new cancer medicine used for gastric cancer and gastroesophageal junction cancer (GEJ), it targets a protein called Claudin 18.2 on cancer cells, kills the cancer cells, and slows tumor growth. Vyloy may help increase the length of time before your cancer progresses and increase your life expectancy, which is sometimes called progression-free survival (PFS) and Overall survival (OS).  Vyloy is given as an infusion into a vein usually every 2 or 3 weeks.

Vyloy is FDA-approved as the first-line treatment for gastric cancer (stomach cancer) and GEJ cancer that is claudin (CLDN) 18.2 positive,  HER2-negative, and spread (metastasized) or cannot be removed by surgery (unresectable).  An FDA-approved test must be used to check if tumors are claudin (CLDN) 18.2 positive. Vyloy (zolbetuximab-clzb) is to be used as a combination therapy with fluoropyrimidine- and platinum-containing chemotherapy,

Vyloy FDA approval was granted on October 18, 2024, after positive results from the GLOW clinical trial (NCT03653507) and SPOTLIGHT clinical trial (NCT03504397). In the SPOTLIGHT trial results showed the median PFS was 10.6 months for the Vyloy/chemotherapy arm compared to  8.7 months for the placebo/chemotherapy group. The median overall survival was 18.2 months for the Vyloy/chemotherapy group compared to 15.5 months for the placebo/chemotherapy group. The chemotherapy regime was mFOLFOX6 (a combination chemotherapy regimen that includes oxaliplatin, leucovorin, and fluorouracil)

How does Vyloy work?

Vyloy mechanism of action (MOA) is as a claudin 18.2 (CLDN18.2)-directed cytolytic antibody. Vyloy works by targeting and binding to a protein (CLDN18.2) on the surface of tumor cells, it then kills cancer cells by antibody-dependent cellular cytotoxicity (ADCC) and complement-dependent cytotoxicity (CDC) which slows tumor growth.

Vyloy side effects

Common Vyloy side effects

Common Vyloy side effects are nausea and vomiting, tiredness (fatigue), fever (pyrexia) decreased appetite, diarrhea, tingling or numbness of the arms or legs (peripheral sensory neuropathy), stomach pain, constipation, decreased weight, and hypersensitivity reactions. These side effects occurred in 15 % or more of patients when used with mFOLFOX6 or CAPOX treatments in clinical trials.

Common side effects also include changes in laboratory tests including decreased white blood cells, red blood cells, and platelets, low protein (albumin) blood levels, changes in kidney function tests, increase in blood glucose, changes in liver function tests and changes in electrolytes in your blood.

Serious Vyloy side effects

​​Vyloy may cause serious side effects, including severe allergic reactions and severe nausea and vomiting.

Allergic reactions, including anaphylaxis and infusion related reactions. Allergic reactions are common during treatment with this medicine and can sometimes be serious. Serious allergic reactions can happen during or after your infusion, including life-threatening allergic reactions and serious infusion-related reactions that may lead to death. You will be monitored during your infusion and for 2 hours after or longer if needed. Tell your healthcare provider or get emergency medical help right 

• itchy, raised bumps on the skin (hives) 
• breathing problems such as wheezing
• throat tightness or change in voice
• nausea or vomiting
• Fever
• stomach (abdominal) pain
• chest discomfort
• increased saliva
• chills or shaking
• back pain 

Severe nausea and vomiting. Nausea and vomiting are common during treatment with Vyloy and can sometimes be severe. Nausea and vomiting happened more often during the first treatment cycle. Before you receive each infusion, your healthcare provider will give you medicines to help prevent nausea and vomiting. Tell your healthcare provider right away if nausea or vomiting does not go away or gets worse.

Your healthcare provider may slow the rate of your infusion, temporarily stop, or completely stop treatment with VYLOY if you have certain side effects. These are not all of the possible side effects of VYLOY. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Related/similar drugs

 Before receiving  this medicine

Tell your healthcare provider if you have nausea or vomiting.

Pregnancy

Tell your healthcare provider if you are pregnant or plan to become pregnant. It is not known if Vyloy will harm your unborn baby. 

Females and Males of Reproductive Potential Vyloy is used in combination with fluoropyrimidine- or platinum-containing chemotherapy. Refer to the Full Prescribing Information of fluoropyrimidine- and platinum-containing chemotherapy products for pregnancy testing, contraception, and infertility information.

Breastfeeding

Tell your healthcare provider if you are breastfeeding or plan to breastfeed. It is not known if VYLOY passes into your breast milk, the effects on the breastfed child, or the effects on milk production. Because antibodies may be excreted in human milk and because of the potential for adverse reactions in a breastfed child, do NOT breastfeed during treatment with Vyloy and for 8 months after the last dose.

How will I receive Vyloy?

Vyloy will be given to you by intravenous (IV) infusion into your vein, by your helathcare professional.

Before your infusion you will be given medications to help prevent nausea and vomiting.
You will usually receive Vyloy every 2 or 3 weeks depending on the chemotherapy chosen by your healthcare provider. 

Vyloy Dosing information

First dose: 800 mg/m2

Subsequent doses: 600 mg/m2 every 3 weeks or 400 mg/m2 every 2 weeks.

Vyloy is available as 100 mg lyophilized powder in a single-dose vial

For more detailed dosing information, including infusion rates, see Vyloy dosing page.

What other drugs will affect Vyloy?

Tell your healthcare provider about all the medicines you take, including prescription and over-the-counter medicines, vitamins, and herbal supplements.

Many other drugs may interact with this medicine, including prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible interactions are listed on this page.

Storage

Vyloy vials

Store refrigerated at 2ºC to 8ºC (36ºF to 46ºF) in the original carton.

Do not freeze. 

Do not shake.

Reconstituted vial(s)

Store at room temperature 15°C to 30°C (59°F to 86°F) for up to 5 hours if not used immediately. This product does not contain a preservative.

Diluted infusion

Store the prepared infusion bag:

• At room temperature 15°C to 30°C (59°F to 86°F) for no longer than 6 hours from the end of the preparation of the infusion bag to the completion of the infusion. 
• Under refrigeration at 2°C to 8°C (36°F to 46°F) for no longer than 16 hours from the end of the preparation of the infusion bag to the completion of the infusion. Do not freeze. 

Ingredients

Active ingredient: zolbetuximab-clzb 

Inactive ingredients: arginine, polysorbate 80, sucrose, and phosphoric acid to adjust pH. 

Vyloy Company

Vyloy Manufacturer Astellas Pharma US, Inc. Northbrook, Illinois 60062 

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Medical Disclaimer