Impact and experience of participant engagement activities in supporting dapivirine ring use among participants enrolled in the phase III MTN-020/ASPIRE study.

BACKGROUND: Low adherence to investigational products can negatively impact study outcomes, limiting the ability to demonstrate efficacy. To continue advancing potential new HIV prevention technologies, efforts are needed to improve adherence among study participants. In MTN-020/ASPIRE, a phase III randomized, double-blind, placebo-controlled study of the dapivirine vaginal ring carried out across 15 sites in sub-Saharan Africa, a multifaceted approach to adherence support was implemented, including a strong focus on participant engagement activities (PEAs). In this manuscript, we describe PEAs and participant attendance, and analyze the potential impact of PEAs on ring use. METHODS: All sites implemented PEAs and submitted activity and attendance reports to the study management team throughout the study. Participant demographics were collected via case report forms. Residual dapivirine remaining in the last ring returned by each participant was used to estimate drug released from the ring, which was then adjusted for time participants had the ring to calculate probable use categorized into three levels (low/intermittent/high). Product use was connected to PEA attendance using participant identification numbers. We used multivariate Poisson regression with robust standard errors to explore differences in ring use between PEA attendance groups and reviewed qualitative reports for illustrative quotes highlighting participant experiences with PEAs. RESULTS: 2312 of 2629 study participants attended at least one of 389 PEAs conducted across sites. Participant country and partner knowledge of study participation were most strongly associated with PEA attendance (p < 0.005) with age, education, and income status also associated with event attendance (p < 0.05). When controlling for these variables, participants who attended at least one event were more likely to return a last ring showing at least some use (RR = 1.40) than those who never attended an event. There was a stronger correlation between a last returned ring showing use and participant attendance at multiple events (RR = 1.52). CONCLUSIONS: Our analysis supports the growing body of work illustrating the importance of meaningfully engaging research participants to achieve study success and aligns with other analyses of adherence support efforts during ASPIRE. While causation between PEA attendance and product use cannot be established, residual drug levels in returned rings strongly correlated with participant attendance at PEAs, and the benefits of incorporating PEAs should be considered when designing future studies of investigational products.

Use of a Vaginal Ring Containing Dapivirine for HIV-1 Prevention in Women.

BACKGROUND: Antiretroviral medications that are used as prophylaxis can prevent acquisition of human immunodeficiency virus type 1 (HIV-1) infection. However, in clinical trials among African women, the incidence of HIV-1 infection was not reduced, probably because of low adherence. Longer-acting methods of drug delivery, such as vaginal rings, may simplify use of antiretroviral medications and provide HIV-1 protection. METHODS: We conducted a phase 3, randomized, double-blind, placebo-controlled trial of a monthly vaginal ring containing dapivirine, a non-nucleoside HIV-1 reverse-transcriptase inhibitor, involving women between the ages of 18 and 45 years in Malawi, South Africa, Uganda, and Zimbabwe. RESULTS: Among the 2629 women who were enrolled, 168 HIV-1 infections occurred: 71 in the dapivirine group and 97 in the placebo group (incidence, 3.3 and 4.5 per 100 person-years, respectively). The incidence of HIV-1 infection in the dapivirine group was lower by 27% (95% confidence interval [CI], 1 to 46; P=0.046) than that in the placebo group. In an analysis that excluded data from two sites that had reduced rates of retention and adherence, the incidence of HIV-1 infection in the dapivirine group was lower by 37% (95% CI, 12 to 56; P=0.007) than that in the placebo group. In a post hoc analysis, higher rates of HIV-1 protection were observed among women over the age of 21 years (56%; 95% CI, 31 to 71; P<0.001) but not among those 21 years of age or younger (-27%; 95% CI, -133 to 31; P=0.45), a difference that was correlated with reduced adherence. The rates of adverse medical events and antiretroviral resistance among women who acquired HIV-1 infection were similar in the two groups. CONCLUSIONS: A monthly vaginal ring containing dapivirine reduced the risk of HIV-1 infection among African women, with increased efficacy in subgroups with evidence of increased adherence. (Funded by the National Institutes of Health; ClinicalTrials.gov number, NCT01617096 .).

Perceived Risk Among Human Immunodeficiency Virus Serodiscordant Couples in East Africa Taking Oral Pre-Exposure Prophylaxis.

OBJECTIVES: Perceived risk of human immunodeficiency virus (HIV) infection is thought to drive low adherence in pre-exposure prophylaxis (PrEP) trials. We explored the level of perceived risk of incident HIV infection in the Partners PrEP Study, in which adherence was generally high. METHODS: A cross-sectional questionnaire assessed perceived risk of HIV at 12 months after enrollment. Logistic regression was used to analyze the relationship between perceived risk and other demographic and behavioral variables. RESULTS: Three thousand two hundred twenty-six couples from the Partners PrEP Study were included in this analysis. Only 15.4% of participants reported high or moderate perceived risk. Participants at high risk of acquiring HIV were slightly more likely to report high perceived risk (odds ratio, 1.60; 95% confidence interval, 1.30-1.95; P < 0.001); nevertheless, only 20% of participants with high-risk reported high perceived risk. CONCLUSIONS: Participants reported low perceived risk of HIV but were adherent to PrEP. Perceptions of risk are likely socially determined and more complex than Likert scale questionnaires capture.

Risk of drug resistance among persons acquiring HIV within a randomized clinical trial of single- or dual-agent preexposure prophylaxis.

BACKGROUND: Preexposure prophylaxis (PrEP) with emtricitabine plus tenofovir disoproxil fumarate (FTC/TDF) or TDF alone reduces the risk of human immunodeficiency virus (HIV) acquisition. Understanding the risk of antiretroviral resistance selected by PrEP during breakthrough infections is important because of the risk of treatment failure during subsequent antiretroviral use. METHODS: Within the largest randomized trial of FTC/TDF versus TDF as PrEP, plasma samples were tested for HIV with resistance mutations associated with FTC (K65R and M184IV) and TDF (K65R and K70E), using 454 sequencing. RESULTS: Of 121 HIV seroconverters, 25 received FTC/TDF, 38 received TDF, and 58 received placebo. Plasma drug levels in 26 individuals indicated PrEP use during or after HIV acquisition, of which 5 had virus with resistance mutations associated with their PrEP regimen. Among those with PrEP drug detected during infection, resistance was more frequent in the FTC/TDF arm (4 of 7 [57%]), compared with the TDF arm (1 of 19 [5.3%]; P = .01), owing to the FTC-associated mutation M184IV. Of these cases, 3 had unrecognized acute infection at PrEP randomization, and 2 were HIV negative at enrollment. CONCLUSIONS: These results suggest that resistance selected by PrEP is rare but can occur both with PrEP initiation during acute seronegative HIV infection and in PrEP breakthrough infections and that FTC is associated with a greater frequency of resistance mutations than TDF.

Antiretroviral prophylaxis for HIV prevention in heterosexual men and women.

BACKGROUND: Antiretroviral preexposure prophylaxis is a promising approach for preventing human immunodeficiency virus type 1 (HIV-1) infection in heterosexual populations. METHODS: We conducted a randomized trial of oral antiretroviral therapy for use as preexposure prophylaxis among HIV-1-serodiscordant heterosexual couples from Kenya and Uganda. The HIV-1-seronegative partner in each couple was randomly assigned to one of three study regimens--once-daily tenofovir (TDF), combination tenofovir-emtricitabine (TDF-FTC), or matching placebo--and followed monthly for up to 36 months. At enrollment, the HIV-1-seropositive partners were not eligible for antiretroviral therapy, according to national guidelines. All couples received standard HIV-1 treatment and prevention services. RESULTS: We enrolled 4758 couples, of whom 4747 were followed: 1584 randomly assigned to TDF, 1579 to TDF-FTC, and 1584 to placebo. For 62% of the couples followed, the HIV-1-seronegative partner was male. Among HIV-1-seropositive participants, the median CD4 count was 495 cells per cubic millimeter (interquartile range, 375 to 662). A total of 82 HIV-1 infections occurred in seronegative participants during the study, 17 in the TDF group (incidence, 0.65 per 100 person-years), 13 in the TDF-FTC group (incidence, 0.50 per 100 person-years), and 52 in the placebo group (incidence, 1.99 per 100 person-years), indicating a relative reduction of 67% in the incidence of HIV-1 with TDF (95% confidence interval [CI], 44 to 81; P<0.001) and of 75% with TDF-FTC (95% CI, 55 to 87; P<0.001). Protective effects of TDF-FTC and TDF alone against HIV-1 were not significantly different (P=0.23), and both study medications significantly reduced the HIV-1 incidence among both men and women. The rate of serious adverse events was similar across the study groups. Eight participants receiving active treatment were found to have been infected with HIV-1 at baseline, and among these eight, antiretroviral resistance developed in two during the study. CONCLUSIONS: Oral TDF and TDF-FTC both protect against HIV-1 infection in heterosexual men and women. (Funded by the Bill and Melinda Gates Foundation; Partners PrEP ClinicalTrials.gov number, NCT00557245.).

Mortality in members of HIV-1 serodiscordant couples in Africa and implications for antiretroviral therapy initiation: results of analyses from a multicenter randomized trial.

BACKGROUND: The risk of HIV-1 related mortality is strongly related to CD4 count. Guidance on optimal timing for initiation of antiretroviral therapy (ART) is still evolving, but the contribution of HIV-1 infection to excess mortality at CD4 cell counts above thresholds for HIV-1 treatment has not been fully described, especially in resource-poor settings. To compare mortality among HIV-1 infected and uninfected members of HIV-1 serodiscordant couples followed for up to 24 months, we conducted a secondary data analysis examining mortality among HIV-1 serodiscordant couples participating in a multicenter, randomized controlled trial at 14 sites in seven sub-Saharan African countries. METHODS: Predictors of death were examined using Cox regression and excess mortality by CD4 count and plasma HIV-1 RNA was computed using Poisson regression for correlated data. RESULTS: Among 3295 HIV serodiscordant couples, we observed 109 deaths from any cause (74 deaths among HIV-1 infected and 25 among HIV-1 uninfected persons). Among HIV-1 infected persons, the risk of death increased with lower CD4 count and higher plasma viral levels. HIV-1 infected persons had excess mortality due to medical causes of 15.2 deaths/1000 person years at CD4 counts of 250 - 349 cells/µl and 8.9 deaths at CD4 counts of 350 - 499 cells/µl. Above a CD4 count of 500 cells/µl, mortality was comparable among HIV-1 infected and uninfected persons. CONCLUSIONS: Among African serodiscordant couples, there is a high rate of mortality attributable to HIV-1 infection at CD4 counts above the current threshold (200 - 350 cells/µl) for ART initiation in many African countries. These data indicate that earlier initiation of treatment is likely to provide clinical benefit if further expansion of ART access can be achieved. TRIAL REGISTRATION: Clinicaltrials.gov (NCT00194519).

Response to antiretroviral therapy after a single, peripartum dose of nevirapine.

BACKGROUND: A single dose of nevirapine during labor reduces perinatal transmission of human immunodeficiency virus type 1 (HIV-1) but often leads to viral nevirapine resistance mutations in mothers and infants. METHODS: We studied the response to nevirapine-based antiretroviral treatment among women and infants who had previously been randomly assigned to a single, peripartum dose of nevirapine or placebo in a trial in Botswana involving the prevention of the transmission of HIV-1 from mother to child. All women were treated with antenatal zidovudine. The primary end point for mothers and infants was virologic failure by the 6-month visit after initiation of antiretroviral treatment, estimated within groups by the Kaplan-Meier method. RESULTS: Of 218 women who started antiretroviral treatment, 112 had received a single dose of nevirapine and 106 had received placebo. By the 6-month visit after the initiation of antiretroviral treatment, 5.0% of the women who had received placebo had virologic failure, as compared with 18.4% of those who had received a single dose of nevirapine (P=0.002). Among 60 women starting antiretroviral treatment within 6 months after receiving placebo or a single dose of nevirapine, no women in the placebo group and 41.7% in the nevirapine group had virologic failure (P<0.001). In contrast, virologic failure rates did not differ significantly between the placebo group and the nevirapine group among 158 women starting antiretroviral treatment 6 months or more post partum (7.8% and 12.0%, respectively; P=0.39). Thirty infants also began antiretroviral treatment (15 in the placebo group and 15 in the nevirapine group). Virologic failure by the 6-month visit occurred in significantly more infants who had received a single dose of nevirapine than in infants who had received placebo (P<0.001). Maternal and infant findings did not change qualitatively by 12 and 24 months after the initiation of antiretroviral treatment. CONCLUSIONS: Women who received a single dose of nevirapine to prevent perinatal transmission of HIV-1 had higher rates of virologic failure with subsequent nevirapine-based antiretroviral therapy than did women without previous exposure to nevirapine. However, this applied only when nevirapine-based antiretroviral therapy was initiated within 6 months after receipt of a single, peripartum dose of nevirapine. (ClinicalTrials.gov number, NCT00197587 [ClinicalTrials.gov].).

Genital ulcer disease treatment policies and access to acyclovir in eight sub-Saharan African countries.

BACKGROUND: Herpes simplex virus-2, the most common cause of genital ulcer disease (GUD) globally, is a cofactor in human immunodeficiency virus type-1 (HIV-1) acquisition and transmission. Current World Health Organization guidelines for sexually transmitted infections recommend acyclovir as first-line syndromic treatment of GUD in countries with high herpes simplex virus-2 prevalence (> or =30%). OBJECTIVE: To assess the extent of adoption of acyclovir as syndromic treatment for GUD, and describe procurement, distribution, and cost of acyclovir in the public and private sectors of 8 sub-Saharan African countries. METHODS: We conducted standardized interviews with Ministry of Health (MoH) officials, pharmacists, and other pharmacy workers based in the public and private sectors. Interviews were conducted in Botswana, Kenya, Malawi, South Africa, Tanzania, Uganda, Zambia, and Zimbabwe. Price comparisons were conducted using the 2007 median international reference price (IRP) for acyclovir. RESULTS: Of the 8 African countries, 4 surveyed had adopted acyclovir as first-line syndromic GUD treatment in both their essential medical lists and sexually transmitted infection guidelines. Country-specific acquisition prices for acyclovir 200 mg were comparable to the median IRP and ranged from 0.74 to 1.95 times the median IRP. The median retail cost of acyclovir in the private sector ranged from 5.85 to 9.76 times the median IRP. Public health facilities faced cost and regulatory barriers that impeded the requisitioning of acyclovir from the central medical stores. CONCLUSIONS: Systems for drug procurement, distribution, and access in sub-Saharan African countries need strengthening for a GUD treatment policy using acyclovir to be effective.

Brief Report: Medication Sharing Is Rare Among African HIV-1 Serodiscordant Couples Enrolled in an Efficacy Trial of Oral Pre-exposure Prophylaxis (PrEP) for HIV-1 Prevention.

Sharing of pre-exposure prophylaxis (PrEP) medications is a concern for PrEP implementation. For HIV-1 serodiscordant couples, sharing may undermine the HIV-1 prevention benefit and also cause antiretroviral resistance if taken by HIV-1 infected partners. Within a PrEP efficacy trial among HIV-1 serodiscordant couples, we assessed the occurrence of PrEP sharing by self-report and plasma tenofovir concentrations in HIV-1 infected partners. PrEP sharing was self-reported at <0.01% of visits, and 0%-1.6% of randomly selected and 0% of purposively selected specimens from HIV-1 infected participants had detectable tenofovir concentrations (median: 66.5 ng/mL, range: 1.3-292 ng/mL). PrEP sharing within HIV-1 serodiscordant couples was extremely rare.

Breastfeeding plus infant zidovudine prophylaxis for 6 months vs formula feeding plus infant zidovudine for 1 month to reduce mother-to-child HIV transmission in Botswana: a randomized trial: the Mashi Study.

CONTEXT: Postnatal transmission of human immunodeficiency virus-1 (HIV) via breastfeeding reverses gains achieved by perinatal antiretroviral interventions. OBJECTIVE: To compare the efficacy and safety of 2 infant feeding strategies for the prevention of postnatal mother-to-child HIV transmission. DESIGN, SETTING, AND PATIENTS: A 2 x 2 factorial randomized clinical trial with peripartum (single-dose nevirapine vs placebo) and postpartum infant feeding (formula vs breastfeeding with infant zidovudine prophylaxis) interventions. In Botswana between March 27, 2001, and October 29, 2003, 1200 HIV-positive pregnant women were randomized from 4 district hospitals. Infants were evaluated at birth, monthly until age 7 months, at age 9 months, then every third month through age 18 months. INTERVENTION: All of the mothers received zidovudine 300 mg orally twice daily from 34 weeks' gestation and during labor. Mothers and infants were randomized to receive single-dose nevirapine or placebo. Infants were randomized to 6 months of breastfeeding plus prophylactic infant zidovudine (breastfed plus zidovudine), or formula feeding plus 1 month of infant zidovudine (formula fed). MAIN OUTCOME MEASURES: Primary efficacy (HIV infection by age 7 months and HIV-free survival by age 18 months) and safety (occurrence of infant adverse events by 7 months of age) end points were evaluated in 1179 infants. RESULTS: The 7-month HIV infection rates were 5.6% (32 infants in the formula-fed group) vs 9.0% (51 infants in the breastfed plus zidovudine group) (P = .04; 95% confidence interval for difference, -6.4% to -0.4%). Cumulative mortality or HIV infection rates at 18 months were 80 infants (13.9%, formula fed) vs 86 infants (15.1% breastfed plus zidovudine) (P = .60; 95% confidence interval for difference, -5.3% to 2.9%). Cumulative infant mortality at 7 months was significantly higher for the formula-fed group than for the breastfed plus zidovudine group (9.3% vs 4.9%; P = .003), but this difference diminished beyond month 7 such that the time-to-mortality distributions through age 18 months were not significantly different (P = .21). CONCLUSIONS: Breastfeeding with zidovudine prophylaxis was not as effective as formula feeding in preventing postnatal HIV transmission, but was associated with a lower mortality rate at 7 months. Both strategies had comparable HIV-free survival at 18 months. These results demonstrate the risk of formula feeding to infants in sub-Saharan Africa, and the need for studies of alternative strategies. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00197587.

HIV Transmission Risk Persists During the First 6 Months of Antiretroviral Therapy.

OBJECTIVE: Combination antiretroviral therapy (ART) decreases the risk of sexual HIV transmission by suppressing blood and genital HIV RNA concentrations. We sought to determine HIV transmission risk prior to achieving complete viral suppression. DESIGN: Prospective cohort study. METHODS: Using data from the Partners PrEP Study, a prospective study of 4747 heterosexual HIV-serodiscordant couples in Kenya and Uganda, we examined multiple markers of HIV transmission risk during the first months after ART initiation: time to viral suppression in blood, persistence of HIV RNA in genital specimens, sexual risk behavior, pregnancy incidence, and HIV transmission using survival analysis and generalized estimating equations logistic regression. RESULTS: The cumulative probabilities of achieving blood viral suppression (<80 copies per milliliter) 3, 6, and 9 months after ART initiation were 65.3%, 84.8%, and 89.1%, respectively. Endocervical and seminal HIV RNA were detectable in 12% and 21% of samples obtained within 6 months of ART. Pregnancy incidence was 8.8 per 100 person-years during the first 6 months of ART, and sex unprotected by condoms was reported at 10.5% of visits. Among initially uninfected partners, HIV incidence before ART was 2.08 per 100 person-years (55 infections; 2644 person-years), 1.79 for 0-6 months after ART initiation (3 infections; 168 person-years), and 0.00 with >6 months of ART (0 infections; 167 person-years). CONCLUSIONS: Residual HIV transmission risk persists during the first 6 months of ART, with incomplete viral suppression in blood and genital compartments. For HIV-serodiscordant couples in which the infected partner starts ART, other prevention options are needed, such as pre-exposure prophylaxis, until viral suppression is achieved.

Frequency of false positive rapid HIV serologic tests in African men and women receiving PrEP for HIV prevention: implications for programmatic roll-out of biomedical interventions.

BACKGROUND: Rapid HIV assays are the mainstay of HIV testing globally. Delivery of effective biomedical HIV prevention strategies such as antiretroviral pre-exposure prophylaxis (PrEP) requires periodic HIV testing. Because rapid tests have high (>95%) but imperfect specificity, they are expected to generate some false positive results. METHODS: We assessed the frequency of true and false positive rapid results in the Partners PrEP Study, a randomized, placebo-controlled trial of PrEP. HIV testing was performed monthly using 2 rapid tests done in parallel with HIV enzyme immunoassay (EIA) confirmation following all positive rapid tests. RESULTS: A total of 99,009 monthly HIV tests were performed; 98,743 (99.7%) were dual-rapid HIV negative. Of the 266 visits with ≥1 positive rapid result, 99 (37.2%) had confirmatory positive EIA results (true positives), 155 (58.3%) had negative EIA results (false positives), and 12 (4.5%) had discordant EIA results. In the active PrEP arms, over two-thirds of visits with positive rapid test results were false positive results (69.2%, 110 of 159), although false positive results occurred at <1% (110/65,945) of total visits. CONCLUSIONS: When HIV prevalence or incidence is low due to effective HIV prevention interventions, rapid HIV tests result in a high number of false relative to true positive results, although the absolute number of false results will be low. Program roll-out for effective interventions should plan for quality assurance of HIV testing, mechanisms for confirmatory HIV testing, and counseling strategies for persons with positive rapid test results.

Successful discontinuation of the placebo arm and provision of an effective HIV prevention product after a positive interim efficacy result: the partners PrEP study experience.

BACKGROUND: Dissemination of research results to study participants and stakeholders and provision of proven effective products in the immediate post-trial period are core elements of the conduct of biomedical HIV prevention clinical trials. Few biomedical HIV prevention trials have demonstrated HIV protection with novel interventions, and thus, communication of positive trial results and provision of an effective product have not been tested in many situations. METHODS: In July 2011, the independent Data and Safety Monitoring Board of the Partners PrEP Study, a randomized, placebo-controlled efficacy trial of daily oral antiretroviral preexposure prophylaxis (PrEP) for HIV prevention among 4747 African heterosexual HIV serodiscordant couples, recommended discontinuation of the trial's placebo arm due to demonstration of PrEP efficacy. We describe dissemination of results, discontinuation of the placebo arm, and provision of active PrEP to participants' formerly assigned placebo. RESULTS: Within 72 hours, of the Data and Safety Monitoring Board meeting the study results were publicly released and disseminated to stakeholders and study participants. Within 3 months, the study protocol was modified to permit participants initially assigned to the study's placebo arm to be offered active PrEP. Of the 1418 participants initially randomized to placebo who were clinically eligible to receive PrEP, 89.1% (1264/1418) consented. CONCLUSIONS: Prompt dissemination of a positive HIV prevention trial result and subsequent provision of effective product to research participants was feasible and efficient for >4700 HIV serodiscordant couples in East Africa. The extent to which study sponsors can assure continued product access to research participants remains a subject of discussion for future HIV prevention clinical trials.

HIV protective efficacy and correlates of tenofovir blood concentrations in a clinical trial of PrEP for HIV prevention.

BACKGROUND: Antiretroviral pre-exposure prophylaxis (PrEP) is a novel HIV prevention strategy for which adherence is a known determinant of efficacy. Blood concentrations of PrEP medications are one objective marker of adherence. METHODS: In a placebo-controlled PrEP efficacy trial of tenofovir disoproxil fumarate (TDF) and TDF with emtricitabine (FTC/TDF) among 4747 African women and men with an HIV-infected partner, we measured plasma tenofovir concentrations from participants in the active PrEP arms: 29 HIV seroconverters (cases) and 196 randomly selected controls who remained uninfected. RESULTS: Among controls, 71% of visits had tenofovir concentrations >40 ng/mL, consistent with steady-state daily dosing, compared with 21% of cases at the visit HIV was first detected. Pill count data indicated that 96% of controls and 66% of cases had >80% adherence for these same visits. The estimated protective effect of PrEP against HIV, based on concentrations >40 ng/mL, was 88% (95% confidence interval: 60 to 96, P < 0.001) for individuals receiving TDF and 91% (95% confidence interval: 47 to 98, P = 0.008) for individuals receiving FTC/TDF. Controls had consistent patterns of PrEP concentrations during follow-up; among the 81% with concentrations >40 ng/mL at month 1, 75% maintained this concentration at month 12. Only 5 of 29 seroconverters seemed to be consistently adherent to PrEP. Tenofovir concentrations >40 ng/mL were associated with older age and shorter time on study; concentrations ≤40 ng/mL occurred more commonly when participants reported no sex with their HIV-infected partner. CONCLUSIONS: Plasma concentrations of tenofovir consistent with daily dosing were highly predictive of protection from HIV acquisition. Most of those who took PrEP seemed to have high and consistent adherence.

Single-agent tenofovir versus combination emtricitabine plus tenofovir for pre-exposure prophylaxis for HIV-1 acquisition: an update of data from a randomised, double-blind, phase 3 trial.

BACKGROUND: Antiretroviral pre-exposure prophylaxis (PrEP), with daily oral tenofovir disoproxil fumarate or tenofovir disoproxil fumarate in combination with emtricitabine, has been shown to be efficacious for HIV-1 prevention. Although the use of more than one antiretroviral agent is essential for effective HIV-1 treatment, more than one agent might not be required for effective prophylaxis. We assessed the efficacy of single-agent tenofovir disoproxil fumarate relative to combination emtricitabine plus tenofovir disoproxil fumarate as PrEP. METHODS: We did a randomised, double-blind, placebo-controlled three-group phase 3 trial of daily oral tenofovir disoproxil fumarate and emtricitabine plus tenofovir disoproxil fumarate PrEP in HIV-1 uninfected individuals in heterosexual HIV-1 serodiscordant couples from Kenya and Uganda. After an interim review, the trial's placebo group was discontinued and thereafter the active groups were continued, and participants initially randomly assigned to placebo were offered rerandomisation in a 1:1 ratio to tenofovir disoproxil fumarate or emtricitabine plus tenofovir disoproxil fumarate as PrEP. The primary endpoints were HIV-1 seroconversion and safety. This trial is registered with ClinicalTrials.gov, number NCT00557245. FINDINGS: 4410 (99·6%) of 4427 couples received tenofovir disoproxil fumarate or emtricitabine plus tenofovir disoproxil fumarate and were followed up for HIV-1 acquisition. Of 52 incident HIV-1 infections, 31 occurred in individuals assigned tenofovir disoproxil fumarate (incidence 0·71 cases per 100 person-years) and 21 were in those assigned emtricitabine plus tenofovir disoproxil fumarate (0·48 cases per 100 person-years); HIV-1 incidence in the placebo group until discontinuation was two cases per 100 person-years. HIV-1 prevention efficacy with emtricitabine plus tenofovir disoproxil fumarate was not significantly different from that of tenofovir disoproxil fumarate alone (hazard ratio [HR] 0·67, 95% CI 0·39-1·17; p=0·16). Detection of tenofovir in plasma samples, compared with no detection and as measured in seroconverters and a subset of non-seroconverters, was associated with an 85% relative risk reduction in HIV-1 acquisition for the tenofovir disoproxil fumarate group (HR 0·15, 95% CI 0·06-0·37; p<0·0001) and 93% for the emtricitabine plus tenofovir disoproxil fumarate group (0·07, 0·02-0·23; p<0·0001). No significant differences were noted in the frequency of deaths, serious adverse events, or serum creatinine and phosphorus abnormalities between the two groups. INTERPRETATION: These results do not rule out the potential for a slight difference in HIV-1 protection with tenofovir disoproxil fumarate compared with emtricitabine plus tenofovir disoproxil fumarate, but show that once-daily oral tenofovir disoproxil fumarate or emtricitabine plus tenofovir disoproxil fumarate regimens both provide high protection against HIV-1 acquisition in heterosexual men and women. FUNDING: Bill & Melinda Gates Foundation and US National Institutes of Health.

Sexual behaviour of heterosexual men and women receiving antiretroviral pre-exposure prophylaxis for HIV prevention: a longitudinal analysis.

BACKGROUND: Scarce data are available to assess sexual behaviour of individuals using antiretroviral pre-exposure prophylaxis for HIV prevention. Increased sexual risk taking by individuals using effective HIV prevention strategies, like pre-exposure prophylaxis, could offset the benefits of HIV prevention. We studied whether the use of pre-exposure prophylaxis in HIV-uninfected men and women in HIV-serodiscordant couples was associated with increased sexual risk behaviour. METHODS: We undertook a longitudinal analysis of data from the Partners PrEP Study, a double-blind, randomised, placebo-controlled trial of daily oral pre-exposure prophylaxis among HIV-uninfected partners of heterosexual HIV-serodiscordant couples (n=3163, ≥18 years of age). Efficacy for HIV prevention was publicly reported in July 2011, and participants continued monthly follow-up thereafter. We used regression analyses to compare the frequency of sex-unprotected by a condom-during the 12 months after compared with the 12 months before July 2011, to assess whether knowledge of pre-exposure prophylaxis efficacy for HIV prevention caused increased sexual risk behaviour. RESULTS: We analysed 56 132 person-months from 3024 HIV-uninfected individuals (64% male). The average frequency of unprotected sex with the HIV-infected study partner was 59 per 100 person-months before unmasking versus 53 after unmasking; we recorded no immediate change (p=0·66) or change over time (p=0·25) after July, 2011. We identified a significant increase in unprotected sex with outside partners after July, 2011, but the effect was small (average of 6·8 unprotected sex acts per year vs 6·2 acts in a predicted counterfactual scenario had patients remained masked, p=0·04). Compared with before July, 2011, we noted no significant increase in incident sexually transmitted infections or pregnancy after July, 2011. INTERPRETATION: Pre-exposure prophylaxis, provided as part of a comprehensive prevention package, might not result in substantial changes in risk-taking sexual behaviour by heterosexual couples. FUNDING: The Bill & Melinda Gates Foundation and the US National Institute of Mental Health.

Outside sexual partnerships and risk of HIV acquisition for HIV uninfected partners in African HIV serodiscordant partnerships.

BACKGROUND: As African countries scale-up couples HIV testing, little is known about sexual behaviors and HIV risk for HIV-uninfected partners in known HIV-serodiscordant relationships. METHODS: We conducted a prospective study of 3380 HIV-serodiscordant partnerships from 7 African countries. Self-reported sexual behavior data were collected quarterly from HIV-uninfected partners. RESULTS: The proportion of HIV-uninfected partners reporting sex with their known primary HIV-infected partner decreased during follow-up (from 93.5% in the prior month at baseline to 73.2% at 24 months, P < 0.001). Simultaneously, an increasing proportion reported sex with an outside partner (from 3.1% to 13.9%, P < 0.001). A small proportion (<5%, stable throughout follow-up) reported sex with the infected partner and an outside partner in the same month (concurrent). Unprotected sex was more common with outside partners than with their primary known HIV-infected partners (risk ratio 4.6; 95% confidence interval: 4.2 to 5.2). HIV incidence was similar for those reporting sex only with their primary HIV-infected partner compared with those who reported an outside partner (2.87 vs. 3.02 per 100 person-years, P = 0.7), although those who had outside partners were more likely to acquire HIV that was virologically distinct from that of their primary partner (P < 0.001). CONCLUSION: For uninfected members of HIV-serodiscordant couples, sex with the infected partner declined as sex with outside partners increased, likely reflecting relationship dissolution and risk shifting from a known infected partner. Risk-reduction messages for HIV-uninfected partners in serodiscordant partnerships should include strategies to reduce HIV acquisition from outside partners.

Characteristics of HIV-1 serodiscordant couples enrolled in a clinical trial of antiretroviral pre-exposure prophylaxis for HIV-1 prevention.

INTRODUCTION: Stable heterosexual HIV-1 serodiscordant couples in Africa have high HIV-1 transmission rates and are a critical population for evaluation of new HIV-1 prevention strategies. The Partners PrEP Study is a randomized, double-blind, placebo-controlled trial of tenofovir and emtricitabine-tenofovir pre-exposure prophylaxis to decrease HIV-1 acquisition within heterosexual HIV-1 serodiscordant couples. We describe the trial design and characteristics of the study cohort. METHODS: HIV-1 serodiscordant couples, in which the HIV-1 infected partner did not meet national guidelines for initiation of antiretroviral therapy, were enrolled at 9 research sites in Kenya and Uganda. The HIV-1 susceptible partner was randomized to daily oral tenofovir, emtricitabine-tenofovir, or matching placebo with monthly follow-up for 24-36 months. RESULTS: From July 2008 to November 2010, 7920 HIV-1 serodiscordant couples were screened and 4758 enrolled. For 62% (2966/4758) of enrolled couples, the HIV-1 susceptible partner was male. Median age was 33 years for HIV-1 susceptible and HIV-1 infected partners [IQR (28-40) and (26-39) respectively]. Most couples (98%) were married, with a median duration of partnership of 7.0 years (IQR 3.0-14.0) and recent knowledge of their serodiscordant status [median 0.4 years (IQR 0.1-2.0)]. During the month prior to enrollment, couples reported a median of 4 sex acts (IQR 2-8); 27% reported unprotected sex and 14% of male and 1% of female HIV-1 susceptible partners reported sex with outside partners. Among HIV-1 infected partners, the median plasma HIV-1 level was 3.94 log(10) copies/mL (IQR 3.31-4.53) and median CD4 count was 496 cells/µL (IQR 375-662); the majority (64%) had WHO stage 1 HIV-1 disease. CONCLUSIONS: Couples at high risk of HIV-1 transmission were rapidly recruited into the Partners PrEP Study, the largest efficacy trial of oral PrEP. (ClinicalTrials.gov NCT00557245).

Perceptions of couple HIV counseling and testing in Botswana: a stakeholder analysis.

OBJECTIVE: To explore stakeholder's perceptions of Couples HIV Counseling and Testing (CHCT) as opposed to individual testing and potential couples' preferences for CHCT promotion and service provision. METHODS: Study was conducted as formative research for a phase III clinical trial of Herpes (HSV-2) suppression to prevent HIV transmission among HIV discordant couples. We used non-probability purposive sampling and snowballing techniques to identify study participants. Data were collected using key informant interviews and focus group discussions. Systematic textual data analysis was used. Two independent coders coded and compared their codes for agreement. Data was categorized by emerging themes. RESULTS: The general themes from both key informant interviews and focus group discussions were a preference for CHCT as opposed to individual counseling in HIV prevention and the need for a client-centered approach to promotion and provision of couple HIV testing services. CONCLUSION: CHCT is important in HIV prevention and should be integrated in existing HIV testing programs. The study also demonstrates the challenges of HIV status disclosure and discordance among sexual partners who test as individuals. PRACTICE IMPLICATIONS: Current low HIV status disclosure rates imply that reducing HIV incidence rates will require integrating CHCT into current testing programs. Increasing CHCT uptake however, requires improving access, training providers and addressing social, cultural, political and logistical barriers.

Risk factors for early and late transmission of HIV via breast-feeding among infants born to HIV-infected women in a randomized clinical trial in Botswana.

Risk factors for mother-to-child transmission (MTCT) of human immunodeficiency virus (HIV) via breast-feeding were evaluated in a randomized trial. HIV-infected women and their infants received zidovudine as well as single-dose nevirapine or placebo. Infants were randomized to formula-feed (FF) or breast-feed (BF) in combination with zidovudine prophylaxis. Of 1116 at-risk infants, 6 (1.1%) in the FF group and 7 (1.3%) in the BF group were infected between birth and 1 month (P=.99). Maternal receipt of nevirapine did not predict early MTCT in the BF group (P=.45). Of 547 infants in the BF group at risk for late MTCT, 24 (4.4%) were infected. Maternal HIV-1 RNA levels in plasma (P<.001) and breast milk (P<.001) predicted late MTCT. These findings support the safety of 1 month of breast-feeding in combination with maternal and infant antiretroviral prophylaxis. Trial registration. ClinicalTrials.gov identifiers: NCT00197691 and NCT00197652.