Pharmacokinetics and Safety of an Antirhinoviral Agent, Ruprintrivir, in Healthy Volunteers

A single-dose study and a multiple-dose study of the safety and pharmacokinetics of ruprintrivir, a new selective irreversible inhibitor of human rhinovirus 3C protease, were conducted with healthy adult volunteers. Both studies were double-blind, randomized, placebo-controlled, parallel-group investigations of ruprintrivir administered intranasally at two dose levels. The parent drug and its acid metabolite, AG7185, were measured in plasma samples and nasal washings, and the safety of the treatments was monitored. Intranasal ruprintrivir, administered as single doses of 4 and 8 mg or every 3 h, six times per day, for 7 days was safe and well tolerated. Adverse events were mild, short-lived, and confined to the upper respiratory tract (i.e., nose and throat, taste and smell perceptions). Adverse events were similar after placebo and after single or multiple doses of active drug. Systemic exposure to ruprintrivir was rarely detectable with the highest measured concentration of < or =0.52 ng/ml; the assay had a lower limit of quantification of 0.2 ng/ml. Systemic exposure to the metabolite was also low, with a highest measured concentration of 3.25 ng/ml. Concentrations of AG7185 observed during multiple dosing were higher than those observed after the first dose but were no more than predicted from the single-dose study. Substantial amounts of ruprintrivir were observed intranasally for at least 9 h after multiple doses of ruprintrivir.