Randomized, Double-Blind, Multicenter Safety and Efficacy Study of Rifalazil Compared with Azithromycin for Treatment of Uncomplicated Genital Chlamydia trachomatis Infection in Women

Abstract

ABSTRACTA randomized, double-blind study comparing single-dose chlamydia therapies of oral rifalazil (25 mg) and azithromycin (1 g) was conducted in 82 women with uncomplicated genitalChlamydia trachomatisinfection. The microbiologic cure rate ofC. trachomatiswith rifalazil (n= 33) was 84.8% at the visit on day 22 to 26 (test-of-cure visit), versus 92.1% with azithromycin (n= 38), and the number of treatment failures in each group was 5 and 3, respectively. The difference in cure rate was −7.3%, with a lower limit of the 95% confidence interval (95% CI) of −22.5, and thus, noninferiority was not established at the prespecified margin (lower limit of CI of −15%). The overall treatment-emergent adverse event (TEAE) and treatment-related TEAE rates were lower in the rifalazil group (68% and 55%) than in the azithromycin group (71% and 62%), respectively. Subjects classified as treatment failures at day 22 to 26 had a lower mean plasma concentration of rifalazil at the visit on day 8 to 12 than those classified as treatment cures, but this difference was not significant; however, the levels were similar for both groups at the visit on day 22 to 26. A single 25-mg dose of rifalazil was well tolerated and eradicatedC. trachomatisin most of these women with uncomplicated genitalC. trachomatisinfection. (The study was registered at clinicaltrials.gov under registration no. NCT01631201).