Microbicide Safety and Acceptability in Young Men

After completing a screening evaluation, 280 eligible participants, including 40 sex workers, will be enrolled into Stage 1A of the study during which they will undergo a baseline medical evaluation for both history and presence of STIs and anorectal health pathologies or injuries, as well as a detailed Web-based baseline behavioral assessment. The first 140 eligible participants, including 20 sex workers, reporting at least one occasion of unprotected RAI in the previous 3 months will be invited to enroll into Stage 1B. In Stage 1B participants will apply the universal placebo gel (HEC) rectally prior to each episode of RAI over a 3-month period, reporting each use via a phone reporting system; they will complete a Web-based questionnaire and take part in a video teleconference at the end of the 3 months. The first 24 eligible participants completing Stage 1B will be invited to enroll in Stage 2. The subset of sex workers who took part in Stages 1A and 1B will terminate participation at the end of 1B. Eligible participants will be randomized to receive either tenofovir 1% gel or HEC placebo gel as part of Stage 2, the Phase 1 safety study. Following a baseline visit, participants will return to the clinic, where a single dose of the study gel will be administered. Within approximately 30 minutes, rectal swab and rectal biopsy specimens will be obtained via anoscopy. After a one-week recovery period participants will return to the clinic for assessment. If no significant adverse events (AEs) are reported they will begin to self-administer once-daily outpatient doses of the study gel for 7 days, after which they will return to the clinic for evaluation and specimen collection.