Article Text
Abstract
Background Recent studies report that treatment failure rates for single-dose azithromycin for urogenital chlamydia in females may be as high as 8%. There has been sparse research investigating new antibiotics for chlamydia, especially those that may reduce adherence difficulties with the CDC recommended doxycycline regimen (100 mg orally twice daily for 7 days).
Methods The safety and efficacy of WC2031 (doxycycline hyclate delayed-release 200 mg tablet) orally once daily for 7 days vs Vibramycin (doxycycline hyclate capsule) 100 mg orally twice daily for 7 days for the treatment of uncomplicated urogenital chlamydia was evaluated in a randomised, double-blind, double-dummy, active-controlled, multicenter study. Males and nonpregnant females ages 19–45 with a confirmed diagnosis of urogenital chlamydia <14 days prior to enrolment or with a sexual partner with chlamydia were eligible. The study consisted of three visits: baseline, day 8 (end-of-treatment), and day 28 (test-of-cure [TOC]). The primary outcome was microbiological cure at TOC, defined as a negative result for Chlamydia trachomatis by the Gen-Probe (GP) Aptima Combo (AC) 2 assay (on urine in males and vaginal swab in females). The mITT population consisted of treated subjects with a GP AC2 positive for C trachomatis at baseline. Non-inferiority of WC2031 was inferred if the lower limit of the 95% CI of the difference in cure rates was >-10%. Safety was studied through clinical evaluation and laboratory tests.
Results 495 subjects were randomised at 41 study sites. The mITT population with evaluable efficacy consisted of 323 (65%) subjects (156 in the WC 2031 group and 167 in the Vibramycin group). Baseline characteristics did not differ by group: median age 23, 61% female, 58% African American vs 36% Caucasian vs 7% other race, and 21% Hispanic ethnicity. The microbiological cure rate (95% CI) for the WC2031 group was 95.5 % (92.3 to 98.8) vs 95.2% (92.0 to 98.4) for the Vibramycin group; the 95% CI for the difference in cure rates between treatments was (−4.3% to 4.9%). Types of adverse events were comparable between treatment groups. The WC 2031 group had less nausea and vomiting (13% vs 21% and 8% vs 12%).
Conclusions WC2031 was non-inferior to Vibramycin for treatment of uncomplicated urogenital chlamydia, was better tolerated, and demonstrated comparable safety. The once daily dosing of WC2031 may improve treatment adherence compared with twice daily doxycycline.