Zanubrutinib

BTK inhibitors
BTK inhibitors
High alert
An error with this medicine can cause serious harm: double checks and protocols are used.
Pregnancy: avoid
Avoid in pregnancy. Zanubrutinib can harm the fetus: a pregnancy test is done first, women and men use contraception during treatment and for a week after, and breastfeeding is…

A second-generation covalent BTK inhibitor for CLL and several B-cell lymphomas. Watch for bleeding, infections and heart rhythm problems.

Updated Nov 12, 2026

Quick facts

Group: BTK inhibitors
Target: Bruton tyrosine kinase (BTK)
Used for: Chronic lymphocytic leukaemia
Key effects: Diarrhoea · Rash · Muscle
Monitor: Complete blood count · Signs of bleeding and infection
ATC: L01EL03

No doses: the clinician sets them by the current guideline.

Mechanism of action

Bruton tyrosine kinase (BTK)Zanubrutinib

The crystal shows zanubrutinib in the ATP site of the human BTK kinase domain.

Target in 3D: Bruton tyrosine kinase (BTK). PDB structure 6J6M (RCSB PDB, public domain). View the structure at RCSB PDB

B-cell receptor signalling runs through Bruton tyrosine kinase (BTK). Zanubrutinib binds covalently to cysteine 481 in the ATP site of BTK and switches it off permanently. Malignant B cells lose their survival signals and die. It was designed to block BTK more selectively than ibrutinib.

Bonds covalently to cysteine 481 of BTK
B-cell receptor signalling stops
Malignant B cells lose survival signals and die

Indications

Chronic lymphocytic leukaemia or small lymphocytic lymphoma. Chronic lymphocytic leukaemia →
Mantle cell lymphoma after one prior therapy, marginal zone lymphoma after anti-CD20 therapy, and follicular lymphoma with obinutuzumab after two prior therapies. Non-Hodgkin lymphoma →
Waldenström macroglobulinaemia. MGUS and Waldenström macroglobulinaemia →

Adverse effects

Common

Diarrhoea, constipation, nausea
Rash, bruising
Muscle, joint and back pain, muscle spasms
Fatigue, headache, limb swelling
Upper respiratory infections

Contraindications

Hypersensitivity to zanubrutinib

Key interactions

St John's wort: Can lower zanubrutinib levels; avoided.
Omeprazole and other medicines: Listed as interacting; the medication list is reviewed.
Grapefruit and its juice: Can raise zanubrutinib levels; discussed with the treating team.

What is monitored

Complete blood count
Signs of bleeding and infection; hepatitis B status before starting
Pulse and heart rhythm; blood pressure
Skin checks and liver tests

Administration and safety

Oral capsules swallowed whole with water, not opened, chewed or crushed.
It is usually held for a period before and after surgery or dental procedures because of bleeding risk.

Pregnancy and breastfeeding

Avoid in pregnancy. Zanubrutinib can harm the fetus: a pregnancy test is done first, women and men use contraception during treatment and for a week after, and breastfeeding is stopped.

Nursing care

Teach to report bleeding, black stools, severe headache or confusion.
Teach to report palpitations, dizziness or fainting.
Sun protection and skin self-checks.
Tell surgeons and dentists about the drug; contraception during treatment and shortly after.

Pharmacokinetics

Absorption: Oral capsules or tablets once or twice a day, with or without food.

Test yourself

Think of the answer, then tap the question to see it.

Which residue of BTK does zanubrutinib bond covalently?

Cysteine 481.

Which three serious class adverse effects do covalent BTK inhibitors share?

Bleeding, infections and atrial fibrillation (also cytopenias and second cancers).

Which B-cell cancers is zanubrutinib used for?

CLL/SLL, mantle cell, marginal zone and follicular lymphoma, and Waldenström macroglobulinaemia.

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Connections

← Back to the class: BTK inhibitors

Educational content on how drugs work; not a prescribing guide and no substitute for a health professional's advice. No doses are given.

Sources: Zanubrutinib: MedlinePlus Drug Information (MedlinePlus (U.S. National Library of Medicine), 2024); RCSB PDB - 6J6M: Co-crystal structure of BTK kinase domain with Zanubrutinib (RCSB Protein Data Bank, 2026); eEML - Electronic Essential Medicines List (World Health Organization, 2025); ATCDDD - ATC/DDD Index (WHO Collaborating Centre for Drug Statistics Methodology, 2026).

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Representative model, for educational purposes only.