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Background: Globally, herpes simplex virus type 2 (HSV-2) infection is the most common cause of genital ulcer disease. Effective prevention strategies for HSV-2 infection are needed to achieve the goals of the World Health Organization global strategy for the prevention and control of sexually transmitted infections., Methods: We assessed the effectiveness of pericoital tenofovir gel, an antiviral microbicide, in preventing HSV-2 acquisition in a subgroup of 422 HSV-2-negative women enrolled in the Centre for the AIDS Programme of Research in South Africa (CAPRISA) 004 study, a double-blind, randomized, placebo-controlled trial. Incident HSV-2 cases were identified by evidence of seroconversion on an HSV-2 IgG enzyme-linked immunosorbent assay between study enrollment and exit. A confirmatory analysis was performed by Western blot testing., Results: The HSV-2 incidence rate was 10.2 cases per 100 person-years (95% confidence interval [CI], 6.8 to 14.7) among 202 women assigned to tenofovir gel, as compared with 21.0 cases per 100 person-years (95% CI, 16.0 to 27.2) among 222 women assigned to placebo gel (incidence rate ratio, 0.49; 95% CI, 0.30 to 0.77; P=0.003). The HSV-2 incidence rate among the 25 women with vaginal tenofovir concentrations of 10,000 ng per milliliter or more was 5.7 cases per 100 person-years, as compared with 15.5 cases per 100 person-years among the 103 women with no detectable vaginal tenofovir (incidence rate ratio, 0.37; 95% CI, 0.04 to 1.51; P=0.14). As confirmed by Western blot testing, there were 16 HSV-2 seroconversions among women assigned to tenofovir gel as compared with 36 among those assigned to the placebo gel (incidence rate ratio, 0.45; 95% CI, 0.23 to 0.82; P=0.005)., Conclusions: In this study in South Africa, pericoital application of tenofovir gel reduced HSV-2 acquisition in women. (Funded by the U.S. Agency for International Development and others; ClinicalTrials.gov number, NCT00441298.).

Background: The Centre for the AIDS Programme of Research in South Africa (CAPRISA) 004 trial demonstrated a 39% reduction in HIV infection, with a 54% HIV reduction in women who used tenofovir gel consistently. A confirmatory trial is expected to report results in early 2015. In the interim, we have a unique window of opportunity to prepare for and devise effective strategies for the future policy and programmatic scale-up of tenofovir gel provision. One approach is to integrate tenofovir gel provision into family planning (FP) services. The CAPRISA 008 implementation trial provides an opportunity to provide post-trial access to tenofovir gel while generating empiric evidence to assess whether integrating tenofovir gel provision into routine FP services can achieve similar levels of adherence as the CAPRISA 004 trial., Methods/design: This is a two-arm, open-label, randomized controlled non-inferiority trial. A maximum of 700 sexually active, HIV-uninfected women aged 18 years and older who previously participated in an antiretroviral prevention study will be enrolled from an urban and rural site in KwaZulu-Natal, South Africa. The anticipated study duration is 30 months, with active accrual requiring approximately 12 months (following which an open cohort will be maintained) and follow-up continuing for approximately 18 months. At each of the two sites, eligible participants will be randomly assigned to receive tenofovir gel through either FP services (intervention arm) or through the CAPRISA research clinics (control arm). As part of the study intervention, a quality improvement approach will be used to assist the FP services to expand their current services to include tenofovir gel provision., Discussion: This protocol aims to address an important implementation question on whether FP services are able to effectively incorporate tenofovir gel provision for this at-risk group of women in South Africa. Provision of tenofovir gel to the women from the CAPRISA 004 trial meets the ethical obligation for post-trial access, and helps identify a potential avenue for future scale-up of microbicides within the public health system of South Africa., Trial Registration: This trial was registered with the South Africa Department of Health (reference: DOH-27-0812-4129) and ClinicalTrials.gov (reference: NCT01691768) on 05 July 2012.

Overestimating personal protection afforded by participation in a preventive trial, e.g. harboring a "preventive misconception" (PM), raises theoretical ethical concerns about the adequacy of the informed consent process, behavioral disinhibition, and adherence to prevention interventions. Data from the CAPRISA 004 1 % tenofovir gel trial were utilized to empirically evaluate these concerns. We found it necessary to re-think the current definition of PM during evaluation to distinguish between true misconception and reasonable inferences of protection based on increased access to evidence-based prevention interventions and/or clinical care. There was a significant association between PM and decreased condom use (p < 0.0001) and between PM and likelihood to present with an STI symptom (p = 0.023). There was, however, limited evidence in support of PM representing a lack of meaningful informed consent, or to suggest that it impacts adherence. Moreover, considering current insufficiencies in female-initiated HIV prevention interventions, PM is perhaps of limited concern in microbicide trials.

In the CAPRISA 004 trial, adherence was estimated as the proportion of reported sex acts covered by two gel doses, which was assessed by counting returned empty gel applicators. The returned empty applicators were inspected visually in a standardized manner for residue on the outside of the applicator, as an indicator of vaginal insertion. Over 15 months, spanning 11,839 study visits by 838 women, a total of 59,800 returned empty applicators were inspected. By visual assessment, 77.5 % of these applicators appeared to have been inserted. To test the accuracy of the assessment we fitted a Cox model and found that the risk for HIV infection was doubled when less than half of the returned empty applicators had been assessed as not inserted in the vagina. Visual inspection enhanced both the accuracy of the adherence measurement and aided identification of mechanical problems with applicator use experienced by women in the trial.

Young women in sub-Saharan Africa are disproportionately affected by HIV, making the development of women initiated and controlled methods of prevention, including microbicides, a priority. Adherence is pivotal to microbicide efficacy and partner related factors are known to impact adherence. An analysis of disclosure of gel use to sexual partners and adherence in CAPRISA 004 women was conducted to better understand this relationship. Partner disclosure was significantly associated with a modest 4.2 % increased adherence (71.0 vs. 66.8 %, p = 0.03). Most women rated the experience of disclosure as positive, despite 6.7 % of partners expressing a negative reaction.Participants who disclosed were more likely to reside with their regular partner (14.4 vs. 8.4 %; p = 0.01) and reported consistent condom use at baseline (32.9 vs. 20.9 %; p < 0.01). Partner disclosure needs to be better understood as a potential facilitator or barrier to microbicide adherence.

High adherence is key to microbicide effectiveness. Here we provide a description of adherence interventions and the adherence rates achieved in the CAPRISA 004 Tenofovir gel trial. Adherence support for the before-and-after dosing strategy (BAT 24) was provided at enrolment and at each monthly study visit. This initially comprised individual counselling and was replaced midway by a structured theory-based adherence support program (ASP) based on motivational interviewing. The 889 women were followed for an average of 18 months and attended a total of 17,031 monthly visits. On average women reported five sex acts and returned 5.9 empty applicators per month. The adherence rate based on applicator count in relation to all reported sex acts was 72.2 % compared to the 82.0 % self-reported adherence during the last sex act. Adherence support activities, which achieve levels of adherence similar to or better than those achieved by the CAPRISA 004 ASP, will be critical to the success of future microbicide trials.

High adherence is important in microbicide trials, but no adherence interventions to date have demonstrated empiric improvements in microbicide adherence or effectiveness. Approximately midway during the CAPRISA 004 trial, we implemented a novel adherence intervention (Adherence Support Program-ASP), based on an Information-Motivation-Behavioral Skills model and incorporating a Motivational Interviewing approach. We assessed the impact of the ASP on adherence and tenofovir gel effectiveness using a before-and-after comparison. Of the 889 women in the trial, 774 contributed 486.1 women-years of follow-up pre-ASP and 828 contributed 845.7 women-years of follow-up post-ASP. Median adherence rose from 53.6 % pre-ASP to 66.5 % post-ASP. Detectable tenofovir levels increased from 40.6 % pre-ASP to 62.5 % post-ASP in 64 women who had paired tenofovir drug samples. Gel effectiveness improved post-ASP; HIV incidence in the tenofovir gel arm was 24 % lower pre-ASP compared to 47 % lower post-ASP. Following implementation of the ASP, microbicide adherence improved with a concomitant increase in the effectiveness of tenofovir gel.

Background: Antiretroviral prophylaxis may be a critical strategy to reduce periconception HIV transmission. Maximizing the benefit of periconception pharmacologic HIV risk-reduction requires an understanding of the links between pregnancy and adherence to this prevention strategy., Methods: We assessed study gel adherence among women with pregnancies compared to women without pregnancies enrolled in the CAPRISA 004 phase IIB trial of 1% vaginal tenofovir gel. Pregnancy was assessed with monthly urine tests. Adherence was measured monthly and defined as proportion of sex acts covered by two returned, used applicators based on pre- and post-coital dosing. High adherence was defined as a median adherence score of >80%, that is, more than 80% of sex acts were covered by two applications of study gel. A multivariate generalized estimating equations (GEE) model with a binomial distribution was used to assess covariates associated with high adherence (>80%) over time. Median adherence before and after pregnancy was compared using Wilcoxon signed rank test., Results: Among 868 women, 53 had at least 1 pregnancy (4.06 per 100 woman years, 95% CI: 3.04, 5.31). Women with pregnancies had lower median adherence compared to women without pregnancies (50% [IQR: 45-83] vs. 60% [IQR: 50-100], p = 0.02). Women with pregnancies also had a 48% lower odds of high adherence compared to women without pregnancies when adjusting for confounders (aOR 0.52, 95%CI: 0.41-0.66, p<0.0001). Among women with pregnancies, adherence before and after pregnancy was not different (50% [IQR: 46-83] vs. 55% [IQR: 20-100], p = 0.68)., Conclusions: Women with pregnancies were less likely to have high adherence to study gel compared to women without pregnancies. Understanding these differences may inform findings from HIV prevention trials and future implementation of antiretroviral prophylaxis for at-risk women who choose to conceive. The protocol for the parent trial is registered on ClinicalTrials.gov, NCT00441298, http://www.clinicaltrials.gov/ct2/show/NCT00441298.

Background: Tenofovir gel, used vaginally before and after coitus, reduced women's acquisition of HIV by 39%. This is a safety assessment of tenofovir gel, including renal, bone, gastrointestinal, genital and haematological parameters., Methods: In the Centre for the AIDS Programme of Research in South Africa (CAPRISA) 004, a double-blind, randomized placebo-controlled trial, 445 of the 889 eligibly enrolled women were assigned to tenofovir gel. All participants were advised to use the gel vaginally only, with one dose of gel within 12 h before and a second dose as soon as possible after sex, with no more than two doses in 24 h. Clinical and laboratory safety data were collected at monthly and quarterly visits, respectively. Genital assessments were undertaken at enrolment and quarterly thereafter, or as indicated., Results: Women assigned to tenofovir gel were exposed to an average monthly vaginal dose of 240 mg of tenofovir (six applications). In total, six women, three in each group, had mild creatinine elevations, all of which occurred in July/August 2008. The incidence of anaemia was 3.5 and 3.8 per 100 women-years in tenofovir and placebo groups, respectively (P=0.80). Of the six women (four tenofovir and two placebo) experiencing bone fractures, none were associated with abnormal phosphate or calcium values. The proportion of women with diarrhoea was higher in the tenofovir gel group (17% versus 11%; P=0.026). There was no significant increase of any genital adverse event in the tenofovir group., Conclusions: No significant renal, haematological, genital or bone effects were associated with the use of tenofovir gel. Aside from a puzzling increase in diarrhoea, tenofovir gel has an excellent safety profile.

Introduction: More than a million people acquire HIV infection annually. Pre-exposure prophylaxis (PrEP) using antiretrovirals is currently being investigated for HIV prevention. Oral and topical formulations of tenofovir have undergone preclinical and clinical testing to assess acceptability, safety and effectiveness in preventing HIV infection., Areas Covered: The tenofovir drug development pathway from compound discovery, preclinical animal model testing and human testing were reviewed for safety, tolerability and efficacy. Tenofovir is well tolerated and safe when used both systemically or applied topically for HIV prevention. High drug concentrations at the site of HIV transmission and concomitant low systemic drug concentrations are achieved with vaginal application. Coitally applied gel may be the favored prevention option for women compared with the tablets, which may be more suitable for prevention in men and sero-discordant couples. However, recent contradictory effectiveness outcomes in women need to be better understood., Expert Opinion: Emerging evidence has brought new hope that antiretrovirals can potentially change the course of the HIV epidemic when used as early treatment for prevention, as topical or oral PrEP. Although some trial results appear conflicting, behavioral factors, adherence to dosing and pharmacokinetic properties of the different tenofovir formulations and dosing approaches offer plausible explanations for most of the variations in effectiveness observed in different trials.

Background: Young women in sub-Saharan Africa bear a disproportionate burden of HIV infection compared to men but have limited options to reduce their HIV risk. Microbicides could fill an important HIV prevention gap for sexually active women who are unable to successfully negotiate mutual monogamy or condom use., Purpose: This paper describes the baseline sample characteristics in the CAPRISA 004 trial which assessed the safety and effectiveness of the vaginal microbicide, 1% tenofovir gel for HIV prevention in South Africa., Methods: This analysis assessed the baseline demographic, clinical and sexual behavior data of women screened and enrolled into the trial. The characteristics were summarized using descriptive summary measures; expressed as means and percent for categorical variables., Results: HIV prevalence at screening was 25.8% [95% Confidence Interval (CI):23.9-27.7). Of the 889 eligibly enrolled women who contributed follow-up data, rural participants recruited from a family planning (FP) clinic were younger, more likely to be living apart from their regular partner, reported lower coital frequency, had lower condom use (p < 0.001). In contrast, urban participants recruited from a sexually transmitted disease (STD) clinic reported higher numbers of lifetime sexual partners, new partners in the last 30 days and receiving money in exchange for sex (p < 0.001)., Conclusion: The populations selected provide suitable diverse target groups for HIV prevention intervention studies., Trial Registration: ClinicalTrials.gov: NCT 00441298.

The Centre for the AIDS Program of Research in South Africa (CAPRISA) 004 trial assessed the effectiveness and safety of a 1% vaginal gel formulation of tenofovir, a nucleotide reverse transcriptase inhibitor, for the prevention of HIV acquisition in women. A double-blind, randomized controlled trial was conducted comparing tenofovir gel (n = 445 women) with placebo gel (n = 444 women) in sexually active, HIV-uninfected 18- to 40-year-old women in urban and rural KwaZulu-Natal, South Africa. HIV serostatus, safety, sexual behavior, and gel and condom use were assessed at monthly follow-up visits for 30 months. HIV incidence in the tenofovir gel arm was 5.6 per 100 women-years (person time of study observation) (38 out of 680.6 women-years) compared with 9.1 per 100 women-years (60 out of 660.7 women-years) in the placebo gel arm (incidence rate ratio = 0.61; P = 0.017). In high adherers (gel adherence > 80%), HIV incidence was 54% lower (P = 0.025) in the tenofovir gel arm. In intermediate adherers (gel adherence 50 to 80%) and low adherers (gel adherence < 50%), the HIV incidence reduction was 38 and 28%, respectively. Tenofovir gel reduced HIV acquisition by an estimated 39% overall, and by 54% in women with high gel adherence. No increase in the overall adverse event rates was observed. There were no changes in viral load and no tenofovir resistance in HIV seroconverters. Tenofovir gel could potentially fill an important HIV prevention gap, especially for women unable to successfully negotiate mutual monogamy or condom use.