A phase‐1, open‐label, single‐dose study of the pharmacokinetics of buparlisib in subjects with mild to severe hepatic impairment

The pharmacokinetics (PK) and safety of single‐dose buparlisib (30 mg) were assessed in subjects with mild to severe hepatic impairment (n = 6 each) relative to healthy controls (n = 13). Blood samples were collected until 336 hours postdose and evaluated by liquid chromatography tandem mass spectrometry. PK parameters (including area under the curve [AUC(∞)] and C(max)) were derived using noncompartmental analysis. Buparlisib was rapidly absorbed in all groups (median T(max) 1.0–1.3 h). Buparlisib exposure (AUC(∞)) was moderately increased in subjects with mild (geometric mean ratio [GMR] 1.16; 90%CI 0.81, 1.65), moderate (GMR 1.14; 90%CI 0.80, 1.63), or severe (GMR 1.20; 90%CI 0.84, 1.72) hepatic impairment, relative to healthy controls. Apparent oral clearance was similar across groups. Due to a higher unbound fraction in the severe group (0.21) than all other groups (0.17), subjects with severe hepatic impairment had greater exposure to unbound buparlisib (GMR relative to healthy controls: AUC(∞) 1.52; 90%CI 1.09, 2.13; C(max) 1.83; 90%CI 1.42, 2.36). The results indicate that a buparlisib dose adjustment may not be necessary for patients with mild to moderate hepatic impairment. The safety and therapeutic indices should be considered before determining if a dose adjustment is appropriate for patients with severe hepatic impairment.