Doxycycline PEP for Prevention of Sexually Transmitted Infections Among Kenyan Women Using HIV PrEP

This study is an open-label 1:1 randomized clinical trial of doxycyline PEP to reduce bacterial STIs - Neisseria gonorrhoeae, Chlamydia trachomatis, and T. pallidum (syphilis) - among Kenyan women taking PrEP. Participants will be counseled about the preliminary effectiveness data from IPERGAY, and the potential for resistance in STIs or other bacteria. The primary study objectives are to 1) evaluate the effectiveness of doxycycline PEP (dPEP) to reduce STI infections in HIV-uninfected Kenyan women taking HIV PrEP; 2) assess the safety, tolerability, and acceptability of dPEP; 3)assess adherence to dPEP; 4) investigate the impact of dPEP on tetracycline resistance in N. gonorrhoeae and C. trachomatis; 5) measure the cost of dPEP and estimate the cost per case averted, budget impact, and affordability Subjects will be randomized 1:1 to dPEP versus standard of care; randomization will be done in variable-sized blocks and using opaque envelopes opened at randomization. Participants assigned to dPEP will be instructed to take doxycycline 200 mg (two 100mg capsules) orally within 24 hours and up to 72 hours after each condomless sex act (consistent with IPERGAY) as frequently as daily if indicated but not more than once daily. At Months 0,3,6 and 9, women randomized to dPEP will receive doxycycline, sufficient for up to daily use for 3 months (i.e., 180 capsules). Unused capsules will be counted at each quarterly follow-up visit and additional doxycycline will be provided. Participants will also be offered single- or multi-dose pill carriers for ease of dosing dPEP following exposures. All participants will receive quarterly visits for standard of care prevention services and collection of clinical and behavioral data, for a total of 12 months of follow-up.