zanubrutinib

Zanubrutinib is a small-molecule, selective Bruton’s tyrosine kinase (BTK) inhibitor developed for the treatment of certain types of blood cancers. BTK is a key signaling molecule in the B-cell receptor pathway, which is frequently dysregulated in B-cell malignancies, including chronic lymphocytic leukemia (CLL), mantle cell lymphoma (MCL), and Waldenström macroglobulinemia (WM). By inhibiting BTK, zanubrutinib disrupts abnormal B-cell signaling, leading to cell cycle arrest and apoptosis in malignant cells.

The drug was initially studied in phase I clinical trials to assess its safety, tolerability, and pharmacokinetics. Results demonstrated favorable pharmacokinetic properties, with oral bioavailability and a half-life allowing for once-daily dosing. Phase II trials further evaluated zanubrutinib’s efficacy in relapsed or refractory CLL, MCL, and WM, showing promising response rates, including complete and partial remissions. Notably, zanubrutinib exhibited a more favorable safety profile compared to earlier BTK inhibitors, such as ibrutinib, with lower rates of atrial fibrillation and bleeding complications.

Zanubrutinib received accelerated approval from the U.S. Food and Drug Administration (FDA) in 2019 for the treatment of adult patients with MCL who have received at least one prior therapy. It was later approved for WM and CLL based on subsequent clinical evidence. Common side effects include diarrhea, fatigue, muscle pain, and bruising, though serious adverse events such as infections and bleeding may occur. Zanubrutinib is typically administered orally as a capsule, with dose adjustments based on individual patient factors.

Ongoing research continues to explore zanubrutinib’s role in earlier treatment lines and combinations with other therapies to improve outcomes in B-cell malignancies. Its selective inhibition of BTK with a favorable safety profile positions it as a significant advancement in the treatment of these diseases.