Vyloy (zolbetuximab-clzb) is a claudin 18.2-directed cytolytic antibody that was approved in 2024 by the U.S. Food and Drug Administration (FDA) for gastric or gastroesophageal junction adenocarcinoma. Read on to learn more about Astellas' Vyloy, including dosage, adverse reactions, and more.
Medication Overview:
- Brand Name: Vyloy
- Generic Name: Zolbetuximab-clzb
- Treatment for: Gastric or gastroesophageal junction adenocarcinoma
- Manufacturer(s): Astellas
- Initial FDA Approval: October 2024
Vyloy FDA Approval Overview
| Indicated Condition | Indication | Age | Date Approved |
|---|---|---|---|
| Adenocarcinoma | Indicated in combination with fluoropyrimidine- and platinum-containing chemotherapy for the first-line treatment of adults with locally advanced unresectable or metastatic human epidermal growth factor receptor 2 (HER2)-negative gastric or gastroesophageal junction adenocarcinoma whose tumors are claudin (CLDN) 18.2 positive as determined by an FDA-approved test. | Adults | October 2024 |
Warnings and Precautions:
- Hypersensitivity reactions including serious anaphylaxis reactions and serious and fatal infusion-related reactions have occurred. Monitor patients during and for at least two hours after infusion with Vyloy. Interrupt, slow the rate of infusion or permanently discontinue Vyloy based on severity and type of reaction.
Dosage and Administration:
- Administer by intravenous infusion only. Do not administer Vyloy as an intravenous push or bolus.
- The recommended first dose of Vyloy is 800 mg/m2 followed by 600 mg/m2 every three weeks or 400 mg/m2 every two weeks.
Contraindications:
- None.
Adverse Reactions:
- The most common adverse reactions (≥15%) for Vyloy in combination with mFOLFOX6 or Capox were nausea, vomiting, fatigue, decreased appetite, diarrhea, peripheral sensory neuropathy, abdominal pain, constipation, decreased weight, hypersensitivity reactions, and pyrexia.
- The most common laboratory abnormalities (≥15%) for Vyloy in combination with mFOLFOX6 or Capox were decreased neutrophil count, decreased leucocyte count, decreased albumin, increased creatinine, decreased hemoglobin, increased glucose, decreased lymphocyte count, increased aspartate aminotransferase, decreased platelets, increased alkaline phosphatase, increased alanine aminotransferase, decreased glucose, decreased sodium, decreased phosphate, decreased potassium, and decreased magnesium.
Examples of Zolbetuximab in Guidelines
Immunotherapy for the Treatment of Gastrointestinal Cancer
- Society for Immunotherapy of Cancer (SITC), June 2023
- “For patients with locally advanced unresectable or metastatic HER2-negative, CLDN18.2-positive gastric or GEJ adenocarcinoma, zolbetuximab in combination with fluoropyrimidine- and platinum-containing chemotherapy is recommended. There are no comparative data regarding the efficacy of zolbetuximab plus chemotherapy versus an ICI plus chemotherapy where both zolbetuximab and ICI therapy are indicated.”
- European Society for Medical Oncology, February 2024
- “If available, the addition of zolbetuximab to ChT can also be considered for patients with claudin-18.2-positive, HER2-negative tumours in the first-line metastatic disease setting. (At time of writing, this combination has not been approved by the regulatory authorities).”
- “The therapeutic monoclonal antibody zolbetuximab binds CLDN18.2-positive GC cells and has recently been shown to improve clinical outcomes when combined with chemotherapy (ChT) in the treatment of patients with GC”
Please note: This article is current as of November 19, 2025. Consult our clinical guidelines library or drug information tool to ensure you always have the most up-to-date information.
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