Zolbetuximab-clzb

What it is and how it works

Zolbetuximab is a chimeric IgG1 monoclonal antibody that binds claudin 18.2 (CLDN18.2), a tight-junction protein exposed on the surface of many gastric and gastro-oesophageal junction cancer cells. Binding triggers antibody-dependent cellular cytotoxicity and complement-dependent cytotoxicity, leading to tumour cell death; combination with chemotherapy enhances these effects.

Indications

First-line treatment, in combination with fluoropyrimidine- and platinum-containing chemotherapy, of locally advanced unresectable or metastatic HER2-negative gastric or gastro-oesophageal junction adenocarcinoma whose tumours are CLDN18.2-positive.

Dosage and administration (summary)

By intravenous infusion: a loading dose of 800 mg/m² followed by 600 mg/m² every 3 weeks or 400 mg/m² every 2 weeks, together with chemotherapy; the infusion rate is adjusted for nausea, vomiting or infusion reactions.

Contraindications

Hypersensitivity to zolbetuximab or excipients.

Warnings and precautions

Nausea and vomiting are very common, particularly during the first infusion; premedication with antiemetics (e.g. NK1 antagonist plus 5-HT3 antagonist) is recommended, and the infusion may need to be slowed or interrupted. Hypersensitivity and infusion-related reactions, including anaphylaxis, can occur. Monitor fluid and electrolyte status in patients with significant vomiting.

Pregnancy

Data are limited; avoid in pregnancy unless the benefit outweighs the risk, and use effective contraception during treatment.

Storage and supply

Store unopened vials refrigerated at 2–8 °C in the original carton to protect from light; do not freeze.

Source: reference summary prepared from the EU SmPC/EPAR, BNF and WHO Model Formulary. The approved product information in Iran governs.