Abstract

Background

Men who have sex with men (MSM) and transgender women experience high sexually transmitted infection (STI) rates. This study evaluated the feasibility of doxycycline pre-exposure prophylaxis (doxyPrEP) for STI prevention in these key populations.

Methods

Sexually-active MSM and transgender women without human immunodeficiency virus (HIV) with prior syphilis were recruited. Participants initiated HIV PrEP with tenofovir disoproxil fumarate/emtricitabine (TDF/FTC) daily for 48 weeks and were randomized 1:1 to daily doxyPrEP for 48 weeks (immediate arm), or doxyPrEP initiated at 24 weeks (deferred arm). Primary outcomes included adherence, measured using questionnaires, along with tolerability; STI incidence (chlamydia, gonorrhea, syphilis) was a secondary outcome. Nasal carriage of Staphylococccus aureus was assessed serially for doxycycline resistance.

Results

Fifty-two participants were enrolled into the immediate (n = 26) and deferred (n = 26) arms. At 48 weeks, self-reported adherence (≥95%) was 75.0% versus 66.7% (P = .538) for TDF/FTC, and 70.8% versus 61.9% (P = .526) for doxycycline in the immediate versus deferred arms, respectively. No doxyPrEP-related serious adverse events occurred. Incidence of any STI at 24 weeks was reduced in the immediate versus deferred arms, and over 48 weeks, being on doxycycline (vs being off; ie, first 24 weeks of deferred arm) was associated with STI reduction (adjusted odds ratio [aOR] 0.36; 95% confidence interval [CI]: .15–.89). Emergent doxycycline-resistant S. aureus was identified in six individuals, with five in the immediate arm (P = .077).

Conclusions

Dual HIV/doxyPrEP is feasible and associated with a significant reduction in incident STI. Further evaluation of dosing strategies, efficacy and impact on antimicrobial resistance is warranted.

This article is published and distributed under the terms of the Oxford University Press, Standard Journals Publication Model (https://academic.oup.com/pages/standard-publication-reuse-rights)
You do not currently have access to this article.