A Randomized Study of the Single-Dose Safety, Pharmacokinetics, and Food Effect of Chinfloxacin and Its Effect on Thorough QT/QTc Interval in Healthy Chinese Volunteers

Chinfloxacin hydrochloride is a novel tricyclic fluorinated quinolone in development for treatment of conventional and biothreat infections. This first-inhuman randomized study in Chinese healthy subjects was divided into 5 parts. Part A was a single-ascending-dose study to assess safety and tolerability of chinfloxacin. The single-dose pharmacokinetic study, a food effect study, and a multiple-dose pharmacokinetics study were conducted in parts B, C, and D, respectively. Part E was a randomized, placebo-controlled and positive-control single-dose, crossover study to evaluate the effect of chinfloxacin on thorough electrocardiographic QT/corrected QT (QTc) interval. The results suggest that single and multiple oral administrations of chinfloxacin were well tolerated. The observed adverse events (AEs) were dizziness, nausea, weakness, photosensitive dermatitis, and increased frequency of defecation. All AEs were mild and were resolved spontaneously without any treatment. The time to peak plasma concentration (T-max and C-max, respectively) was about 2 h, and the half-life was 14 to 16 h. Food slightly affected the drug's rate and extent of absorption, increasing the T-max from 1.60 to 2.59 h and reducing the C-max by 13.6% and area under the concentration-time curve by 8.95%. Chinfloxacin at 400mg had no effect on prolongation of QT/QTc intervals. Although 600mg chinfloxacin had a mild effect on the prolongation of the QT/QTc interval, the effect was less pronounced than that of the positive control, 400mg moxifloxacin. The pharmacokinetics and safety profiles of chinfloxacin in healthy Chinese volunteers support its once-daily dosing in future clinical investigations.