First Pharmacokinetic and Safety Study in Humans of the Novel Lipid Antiviral Conjugate CMX001, a Broad-Spectrum Oral Drug Active against Double-Stranded DNA Viruses

CMX001 is a novel, broad-spectrum lipid antiviral conjugate (LAC) that produces high intracellular levels of the active antiviral agent cidofovir diphosphate (CDV-PP). Study CMX001-102 was a randomized, double-blind, placebo-controlled, parallel group, dose-escalating study in healthy volunteers. The objectives of the study were to evaluate the safety and pharmacokinetic parameters of CMX001 after single and multiple doses. Single doses ranging from 0.25 to 2.0 mg/kg of body weight and multiple doses ranging from 0.1 to 1.0 mg/kg (3 total doses, administered every 6 days) were given orally. Safety was assessed using comprehensive clinical and laboratory evaluations, including enhanced monitoring for potential gastrointestinal (GI) effects using wireless capsule endoscopy (WCE). Serial plasma and pooled urine samples were collected to estimate pharmacokinetic parameters for both CMX001 and cidofovir (CDV). No adverse events occurred that prevented dose escalation. No clinically significant drug-related changes in blood chemistry, hematology, renal function, or intraocular pressure were observed. No CMX001-related gastrointestinal mucosal changes were observed by WCE. CMX001 was absorbed rapidly, with maximum plasma concentrations observed 2 to 3 h postdose. Maximum plasma drug concentration and systemic exposure of CMX001 increased approximately in proportion to dose following single and multiple doses; no significant accumulation of CMX001 or CDV was observed following multiple doses. We conclude that CMX001 is orally bioavailable and well tolerated in healthy volunteers at doses up to 2 mg/kg, approximately 140 mg in a typical adult. This is the first demonstration of the use of phospholipid conjugation technology to achieve plasma drug exposures that are expected to result in activity against multiple double-stranded DNA viruses.