A phase 1, open-label, single-dose study of the pharmacokinetics of zanubrutinib in subjects with varying degrees of hepatic impairment

The pharmacokinetics and safety of single-dose zanubrutinib (80 mg) were assessed in subjects with mild, moderate, and severe hepatic impairment (n = 6 each, Child-Pugh class A, B, and C) relative to healthy controls (n = 11). Zanubrutinib median T-max was 1.25-2.25 h in all groups. Compared to control group, mean zanubrutinib exposure (AUC(0-inf)) in the mild and moderate hepatic impairment groups was increased by 1.1- and 1.2-fold, which is within the range of PK variability for zanubrutinib. The total and unbound AUC of zanubrutinib were 1.60- and 2.9-fold higher in subjects with severe hepatic impairment compared to healthy controls. Terminal half-life was comparable between subjects with hepatic impairment and matched healthy controls. Zanubrutinib was generally well-tolerated when administered as a single, 80-mg dose to subjects in this study. Results of this study will be used, in conjunction with clinical safety and efficacy data, to develop dose recommendations for patients with hepatic impairment.