A Phase 1, Single‐Dose Study to Evaluate the Pharmacokinetics and Safety of Bepirovirsen in Adults with Hepatic Impairment and Healthy Participants (B‐Assured)

Bepirovirsen is a developmental antisense oligonucleotide (ASO) for treatment of chronic hepatitis B virus infection. No pharmacokinetic (PK) studies comparing participants with hepatic impairment (HI) and healthy participants (HPs) have been conducted with ASOs. Given the target patient population, characterization of bepirovirsen PK in HI was imperative. This phase 1, nonrandomized, open-label study (NCT04971928) evaluated the PKs of a single 300-mg dose of bepirovirsen in participants with HI and matched HPs, enrolled in 2 parts (Part 1: moderate HI; Part 2: mild HI). If no predefined difference in the area under the concentration-time curve from time 0 (predose) to infinite time (AUC_0-∞) and maximum observed concentration (C_max; geometric mean ratio [GMR] 0.5-1.5) was identified in Part 1, findings were applied to mild HI, eliminating Part 2. Participants were monitored for 50 days post-treatment and noncompartmental analysis estimated PK parameters. Twenty-four participants (moderate HI, n = 12; HP, n = 12) received bepirovirsen and completed Part 1. AUC_0-∞ and C_max were lower in participants with moderate HI (GMR 0.69 and 0.67, respectively) than in HPs, while apparent clearance (CL/F) and apparent terminal phase volume of distribution (Vz/F) were higher (GMR 1.44 and 1.64, respectively), but fell within the predefined thresholds of difference for this study. Part 2 was omitted. Adverse events were mild. Moderate HI did not have a clinically relevant impact on bepirovirsen PK or safety.