Studies assessing the pharmacokinetics (PK) of talazoparib suggest that renal excretion of unchanged drug is the major route of talazoparib elimination. This Phase I study assessed the impact of renal impairment on the PK of talazoparib in adult patients with advanced solid tumors and varying degrees of renal dysfunction.

Following administration of multiple 0.5 mg doses of talazoparib, the steady-state exposure of talazoparib increased with worsening renal impairment. Talazoparib exposure increased by 12.2%, 43.0%, and 163.3% in patients with mild, moderate, or severe renal impairment, respectively, when compared with patients with normal renal function.

Overall, this study confirms current dosing recommendations in patients with mild and moderate renal impairment (1 mg/day and 0.75 mg/day, respectively) and indicates that a lower starting dose of 0.5 mg/day should be considered for patients with severe renal impairment. Talazoparib was generally well tolerated, and overall there were no notable differences in the treatment-emergent adverse event profile across renal function groups.