Brukinsa contains the active ingredient zanubrutinib, an oral targeted therapy classified as a Bruton's tyrosine kinase (BTK) inhibitor. It is used in the treatment of several B-cell blood cancers and lymphomas, including chronic lymphocytic leukemia (CLL), small lymphocytic lymphoma (SLL), Waldenström’s macroglobulinemia (WM), mantle cell lymphoma (MCL), and other approved hematologic malignancies.

Zanubrutinib works by selectively blocking BTK, a key enzyme in the B-cell receptor signaling pathway that promotes the growth, survival, and spread of malignant B cells. By inhibiting BTK activity, Brukinsa helps slow cancer progression and induce cancer cell death while minimizing disruption to normal cells.

The medication is administered orally and is available as capsules or tablets, depending on the market. It may be taken once or twice daily according to the prescribed dosing regimen and can be used as monotherapy or in combination with other cancer treatments.

Clinical studies have demonstrated significant efficacy across multiple B-cell malignancies, with durable responses and improved disease control in many patients. Brukinsa is designed to provide highly selective BTK inhibition and has become an important treatment option in modern hematologic oncology.

Common side effects may include decreased white blood cell counts, bruising, upper respiratory tract infections, rash, diarrhea, muscle pain, and fatigue. Serious adverse reactions can include severe infections, bleeding events, heart rhythm abnormalities, and secondary malignancies. Regular monitoring by a healthcare professional is recommended during treatment.