Acceptability of PrEP for HIV prevention among women at high risk for HIV.

OBJECTIVE: To assess the acceptability of a daily pill for prevention of HIV acquisition among 400 Ghanaian women in the oral tenofovir disoproxil fumarate (TDF) clinical trial. METHODS: Structured questionnaires were conducted with women enrolled in the trial at enrollment and at each of the 12 monthly follow-up visits. Growth curve analysis was used to examine adherence patterns over time. Qualitative interviews were carried out with a subsample of the clinical trial population, and thematic analysis was applied to these data. RESULTS: Overall, acceptability of the pill was good. Adherence remained > 82% throughout the 12-month trial. Consistent access to the pill and study assignment were both associated with adherence. Most reported problems diminished over time as women became accustomed to the pill and developed strategies to incorporate pill taking into their daily routines. CONCLUSIONS: If daily preexposure prophylaxis (PrEP) for HIV is found to be efficacious and has as few physical side effects as TDF, acceptability of this method among women in the study population may not be problematic. However, future studies must develop better acceptability measures, in order to more fully address the relationship among adherence, safety, and effectiveness.

Changes in sexual risk behavior among participants in a PrEP HIV prevention trial.

BACKGROUND: One of the concerns raised regarding the introduction of any new HIV-prevention measure, such as PrEP, is the potential for risk disinhibition or sexual risk compensation. The oral tenofovir HIV prevention trial has been the subject of international discussion in this regard. METHODS: This article maps the changes in sexual risk behavior among women participating in the oral tenofovir HIV prevention trial in Ghana. Content-driven, thematic analysis was carried out on qualitative data obtained from in-depth interviews with study participants. Growth curve analysis was the primary method used to document trends over time in self-reported sexual behavior collected monthly. RESULTS: Overall, the study found that sexual risk behavior did not increase during the trial. Number of sexual partners and rate of unprotected sex acts decreased across the 12-month period of study enrollment. Certain subgroups of women, however, exhibited different growth curves. Data indicate that the HIV prevention counseling associated with the trial was effective. CONCLUSIONS: Counseling during the trial was effective. Different types of counseling and messaging may be needed for different subgroups within a population. These findings also have implications for required sample sizes for future HIV prevention trials where seroconversion is the main outcome.

Tenofovir disoproxil fumarate for prevention of HIV infection in women: a phase 2, double-blind, randomized, placebo-controlled trial.

OBJECTIVES: The objective of this trial was to investigate the safety and preliminary effectiveness of a daily dose of 300 mg of tenofovir disoproxil fumarate (TDF) versus placebo in preventing HIV infection in women. DESIGN: This was a phase 2, randomized, double-blind, placebo-controlled trial. SETTING: The study was conducted between June 2004 and March 2006 in Tema, Ghana; Douala, Cameroon; and Ibadan, Nigeria. PARTICIPANTS: We enrolled 936 HIV-negative women at high risk of HIV infection into this study. INTERVENTION: Participants were randomized 1:1 to once daily use of 300 mg of TDF or placebo. OUTCOME MEASURES: The primary safety endpoints were grade 2 or higher serum creatinine elevations (>2.0 mg/dl) for renal function, grade 3 or 4 aspartate aminotransferase or alanine aminotransferase elevations (>170 U/l) for hepatic function, and grade 3 or 4 phosphorus abnormalities (<1.5 mg/dl). The effectiveness endpoint was infection with HIV-1 or HIV-2. RESULTS: Study participants contributed 428 person-years of laboratory testing to the primary safety analysis. No significant differences emerged between treatment groups in clinical or laboratory safety outcomes. Study participants contributed 476 person-years of HIV testing to the primary effectiveness analysis, during which time eight seroconversions occurred. Two were diagnosed in participants randomized to TDF (0.86 per 100 person-years) and six in participants receiving placebo (2.48 per 100 person-years), yielding a rate ratio of 0.35 (95% confidence interval = 0.03-1.93), which did not achieve statistical significance. Owing to premature closures of the Cameroon and Nigeria study sites, the planned person-years of follow-up and study power could not be achieved. CONCLUSION: Daily oral use of TDF in HIV-uninfected women was not associated with increased clinical or laboratory adverse events. Effectiveness could not be conclusively evaluated because of the small number of HIV infections observed during the study.