Safety, tolerability and pharmacokinetics of ASC10, a novel oral double prodrug of a broad-spectrum antiviral agent, ß-d-N4-hydroxycytidine: results from a randomized, double-blind, placebo-controlled phase 1 study in Chinese healthy subjects.

ABSTRACT

BACKGROUND: Considering the rise of new SARS-CoV-2 variants that have reduced the efficacy of COVID-19 vaccines, the development of new antiviral medications for the disease has become increasingly necessary. In this study, ASC10, a novel antiviral prodrug, was studied in a phase 1 trial in healthy Chinese participants. RESEARCH DESIGN AND METHODS: Part 1 involved 60 participants, receiving 50-800 mg ASC10 or placebo twice daily for 5.5 days. Part 2, with 12 participants, explored ASC10 dosing in the fed/fasting states. RESULTS: ASC10-A, the main pharmacologically active metabolite, rapidly appeared in plasma (Tmax 1.00-2.00 h) and decreased (t1/2 1.10-3.04 h) without accumulation. The Cmax and area under the plasma concentration - time curve (AUC) of ASC10-A increased dose-dependently (50-800 mg BID) over 5.5 days, with no accumulation. The Tmax was slightly delayed in the fed state; however, the Cmax and AUC were similar between the fed and fasting states. Adverse events (AEs) were comparable (ASC10/placebo, 66.7%) and mostly mild (95%). CONCLUSION: ASC10 was demonstrated to be safe and well tolerated and exhibited dose-proportional exposure and minimal food effects. CLINICAL TRIAL REGISTRATION www.clinicaltrials.gov identifier is NCT05523141.