Zanubrutinib

What it is and how it works

Zanubrutinib is a second-generation, irreversible inhibitor of Bruton’s tyrosine kinase that binds covalently to a cysteine residue in the BTK active site. BTK inhibition blocks B-cell receptor signalling, reducing malignant B-cell proliferation, survival, trafficking and adhesion; it is more selective for BTK than ibrutinib.

Indications

Waldenström’s macroglobulinaemia; chronic lymphocytic leukaemia; marginal zone lymphoma after prior anti-CD20 therapy; relapsed or refractory follicular lymphoma (with obinutuzumab); and, in some regions, mantle cell lymphoma after prior therapy.

Dosage and administration (summary)

Orally, 320 mg daily, taken either as 160 mg twice daily or 320 mg once daily, with or without food; dose reduction is required with moderate CYP3A inhibitors and in severe hepatic impairment.

Contraindications

Hypersensitivity to zanubrutinib or excipients.

Warnings and precautions

Haemorrhage (including major bleeding), serious infections, cytopenias, atrial fibrillation/flutter and second primary malignancies (especially skin cancers) may occur; monitor blood counts and for signs of bleeding and infection, and consider antimicrobial prophylaxis. Consider withholding around surgery. Avoid strong CYP3A inducers and adjust dose with CYP3A inhibitors.

Pregnancy

Can cause fetal harm; avoid in pregnancy and use effective contraception during and for at least one week after treatment.

Storage and supply

Store below 30 °C (or as specified by the manufacturer).

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