Effect of hepatic impairment on the pharmacokinetics of vilaprisan: An open‐label, single‐dose, parallel‐group study

AIMS: The study objective was to evaluate the pharmacokinetics of the selective progesterone receptor modulator vilaprisan in participants with hepatic impairment. Additionally, the safety and tolerability of vilaprisan were investigated. METHODS: In this phase 1, open‐label, nonrandomised, parallel‐group, pharmacokinetic study, men and women with mild or moderate hepatic impairment (Child–Pugh grade A or B) and control participants with normal hepatic function matched by age, weight and sex received a single oral 2 mg dose of vilaprisan. Key pharmacokinetic parameters, relationships between parameters and safety outcomes were measured. RESULTS: Thirty‐six participants completed the study: 9 with mild hepatic impairment, 9 with moderate hepatic impairment and 18 matched control participants with normal hepatic function. Vilaprisan reached maximum plasma concentrations after 1–2 hours. Unbound vilaprisan exposure was 1.44‐fold higher for participants with mild hepatic impairment vs controls (90% confidence interval: 0.91–2.26), and 1.74‐fold higher for participants with moderate impairment vs controls (90% confidence interval: 1.09–2.78). The maximum observed unbound peak concentrations were similar for participants with hepatic impairment and matched controls. Vilaprisan 2 mg was well tolerated and the incidence of treatment‐emergent adverse events was similar across cohorts. CONCLUSION: Only mild increases of <1.75‐fold in exposure were observed in participants with mild or moderate hepatic impairment compared with control participants. No safety concern was identified. These data, alongside the excellent safety profile observed in phase 1 and 2 studies, do not indicate that a dose adjustment would be required in patients with mild or moderate hepatic impairment.