Microbicides are products that can be applied in the vagina or rectum to decrease the chances of transmission of sexually transmitted infections (STIs) including HIV. In the US, one of the most vulnerable groups for acquiring HIV infection is young men, especially young Black and Latino men who have sex with men (MSM). This study will be conducted with a young 18-30 year-old ethnically diverse sample of HIV-negative MSM who report engaging in receptive anal intercourse (RAI) using condoms inconsistently or not at all. Our goal is to test whether patterns of use of a placebo rectal gel prior to RAI suggest that the product would be used correctly and consistently in real life circumstances and whether this highly vulnerable population could safely use tenofovir gel, a microbicide candidate. In Version 3.0 of this multicentered protocol, a cohort of 40 male and transgender female sex workers were added to Stages 1A and 1B in order to determine the feasibility of recruitment and retention of men who have sex with men (MSM) with high risk sexual behavior, such as sex workers, for microbicide studies, and their likelihood to use noncondom based HIV prevention strategies. This study will be conducted by the University of Pittsburgh in collaboration with researchers at the HIV Center for Clinical and BehavioralStudies at Columbia University; the Fenway Community Health in Boston; and the University of Puerto Rico Clinical Trial Unit in San Juan, Puerto Rico. Subjects will be enrolled at the University of Pittsburgh, Fenway Community Health, and the University of Puerto Rico. This is a two-stage longitudinal study including a clinical and behavioral evaluation (Stage 1A) with an acceptability and adherence trial (Stage 1B), followed by a Phase 1 randomized, double-blind, multi-site, placebo-controlled trial (Stage 2). Participants who complete Stage 1A are eligible to be selected for enrollment into Stage 1B; a similar transition occurs between Stage 1B and Stage 2.~In Stage 1A, approximately 280 MSM between the ages of 18-30 will be enrolled, including a subset of 40 sex workers and will undergo a baseline medical evaluation and a detailed Web-based baseline behavioral assessment.~In Stage 1B, approximately 140 participants from Satge 1A, including a subset of 20 sex workers, will be asked to apply a placebo gel (HEC) rectally prior to each episode of RAI over a 3-month period, reporting each use via a phone reporting system. At the end of the 3 months, participants will complete a Web-based questionnaire and take part in a video teleconference.The first 42 eligible participants, excluding the mal and transgender female sex worker cohort, (approximately 14 at each site) completing Stage 1B with a reported adherence of 80% or greater will be invited to enroll in Stage 2.~In Stage 2, approximately 24 eligible participants from Stage 1B will progress to Stage 2 and be randomized at a 1:1 ratio to tenofovir 1% gel or HEC placebo gel.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, stool, 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.
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.