Effect of hepatic and renal impairment on the pharmacokinetics of olanzapine and samidorphan given in combination as a bilayer tablet

Background: A combination of olanzapine and samidorphan (OLZ/SAM) is in development to provide the established antipsychotic efficacy of olanzapine while mitigating olanzapine-induced weight gain. Methods: Two multicenter, open-label, parallel-cohort studies were performed to evaluate the effect of moderate hepatic impairment (Child-Pugh score 7-9 [class B]; study 1) and severe renal impairment (estimated glomerular filtration rate: 15-29 mL/min/1.73 m(2); study 2) on the pharmacokinetics, safety, and tolerability of a single dose of OLZ/SAM 5/10 mg. Results: There was a 1.67-fold increase in area under the plasma concentration-time curve from time 0 to infinity (AUC(0)(-infinity)) and a 2.17-fold increase in maximum plasma concentration (C-max) of olanzapine, and a 1.52-fold increase in AUC(0-infinity) and a 1.63-fold increase in C-max of samidorphan, in subjects with moderate hepatic impairment compared with healthy control subjects. Compared with healthy control subjects, subjects with severe renal impairment had a 33% and 56% reduction in clearance, a 1.51- and 2.31-fold increase in AUC(0-infinity) and a 1.32-and 1.37-fold increase in C-max of olanzapine and samidorphan, respectively. Conclusion: OLZ/SAM 5/10 mg was generally well tolerated under the conditions of the studies, with a safety profile consistent with that observed in other clinical studies of OLZ/SAM.