Preexposure prophylaxis for HIV prevention

Advances in long-acting slow effective release antiretroviral therapies for treatment and prevention of HIV infection

Adherence to daily oral antiretroviral therapy (ART) is a barrier to both treatment and prevention of human immunodeficiency virus (HIV) infection. To overcome limitations of life-long daily regimen adherence, long-acting (LA) injectable antiretroviral (ARV) drugs, nanoformulations, implants, vaginal rings, microarray patches, and ultra-long-acting (ULA) prodrugs are now available or in development. These medicines enable persons who are or at risk for HIV infection to be treated with simplified ART regimens. First-generation LA cabotegravir, rilpivirine, and lenacapavir injectables and a dapivirine vaginal ring are now in use. However, each remains limited by existing dosing intervals, ease of administration, or difficulties in finding drug partners. ULA ART regimens provide an answer, but to date, such next-generation formulations remain in development. Establishing the niche will require affirmation of extended dosing, improved access, reduced injection volumes, improved pharmacokinetic profiles, selections of combination treatments, and synchronization of healthcare support. Based on such needs, this review highlights recent pharmacological advances and a future treatment perspective. While first-generation LA ARTs are available for HIV care, they remain far from ideal in meeting patient needs. ULA medicines, now in advanced preclinical development, may close gaps toward broader usage and treatment options.

Using an Intersectional Framework to Understand the Challenges of Adopting Pre-exposure Prophylaxis (PrEP) Among Young Adult Black Women

INTRODUCTION

There is limited functional knowledge and utilization of pre-exposure prophylaxis (PrEP) among young adult Black cisgender women (YBW).

METHODS

We conducted four focus groups with YBW using an intersectional framework to explore multiple levels of factors that impede YBW awareness, interest, and utilization of PrEP in conjunction with their sexual and reproductive healthcare needs.

RESULTS

Influences at the cultural-environmental level included a lack of information and resources to access to PrEP and medical mistrust in the healthcare system. At the social normative level, influences included attitudes towards the long-term effects on sexual and reproductive health and self-efficacy to follow the PrEP regimen. At the proximal intrapersonal level, influences included anticipated HIV stigma from family and peers along with the fear of rejection from their main partners.

CONCLUSIONS

Translation of these results indicated that interventions to increase PrEP utilization and adherence among YBW will require multi-level strategies to address barriers to integrating HIV prevention into sexual and reproductive healthcare.

An Exploration of Pre-exposure Prophylaxis (PrEP) Initiation Among Women Who Inject Drugs

Pre-exposure prophylaxis (PrEP) is an effective but understudied tool for preventing HIV among women who inject drugs (WWID). This article is the first to explore WWID's rationale for PrEP initiation (or refusal) in a real-world setting. Purposive sampling was used to recruit 25 WWID, participating in a PrEP demonstration project operating within a syringe services program, based on whether they initiated or declined PrEP care. Content analysis of qualitative interviews was used to explore decisions to initiate PrEP (or not). We found that WWID view HIV as severe, perceive themselves to be susceptible to HIV, and believe PrEP is beneficial for HIV prevention. For some, however, real and perceived barriers outweighed benefits, leading to decisions not to initiate PrEP. Barriers included HIV stigma, fear of side effects, and needing assurance that PrEP care will be available long-term. Despite viewing PrEP as an important HIV prevention tool, not all WWID who were offered PrEP initiated it. For these women, supports to buffer perceived barriers to initiation and access to post-exposure prophylaxis may be warranted. For women who initiate, it is possible that adherence will wane if perceived risk does not remain high. Research to understand PrEP persistence is needed.

HIV prevalence and related behaviours of older people in Botswana - secondary analysis of the Botswana AIDS Impact Survey (BAIS) IV

The focus of HIV interventions in Botswana, a country with the second highest prevalence of HIV in the world, remains targeted at those aged 15-49 years despite a growing cohort of older people living with the disease - driven largely by the successful roll-out of antiretroviral therapy (ART). Primarily utilising the Botswana AIDS Impact Survey IV, we set out to examine HIV related characteristics and behaviours of this often ignored older cohort (50-64 years) relative to younger (25-49 years) adults. Analysis revealed that more than 80% of older people living with HIV were on ART. HIV prevalence among this older cohort was 24.6% in 2013 compared to 35.1% among the younger cohort, p < 0.0001. Prevalence in older adults was higher among older males (27.8%) than females (21.9%), p = 0.02. Furthermore, 58.9% of older adults acknowledged being sexually active, with 59.0% of these admitting to inconsistent condom use during sexual intercourse. In addition to this low condom usage, older men (6.0%) were significantly more likely to be unaware of their HIV-positive status than older women (3.0%), p = 0.002. While HIV prevalence showed a dramatic increase among older men over time (17.2% in 2004, to 23.4% in 2008, to 27.8% in 2013), the trend was flatter among older women (16.3% in 2004, to 22.4% in 2008, to 21.9% in 2013). These trends are likely attributable to a large increase in ART coverage and uptake. Going forward, more targeted interventions acknowledging the ageing epidemic are important to consider.

Expanding the Menu of HIV Prevention Options: A Qualitative Study of Experiences with Long-Acting Injectable Cabotegravir as PrEP in the Context of a Phase II Trial in the United States

Adherence challenges with oral pre-exposure prophylaxis have stimulated interest in alternate modes of administration including long-acting injections. We conducted 30 in-depth interviews with 26 male trial participants and 4 clinical providers in a Phase IIa study (ÉCLAIR) evaluating the use of long-acting cabotegravir (CAB-LA) injections in New York and San Francisco. Interviews exploring attitudes and experiences with CAB-LA were audiotaped, transcribed, and analyzed using thematic content analysis. Despite a high frequency of some level of side effects, almost all participants reported being interested in continuing with CAB-LA, versus a daily oral, due to its convenience and the perceived advantage of not worrying about adhering to pills. Providers reinforced the importance of CAB-LA as a prevention option and the need for guidelines to assist patient decision-making. Further research is needed on the acceptability of CAB-LA among men and women at higher risk for HIV in different settings.

Treatment and prevention of HIV infection with long-acting antiretrovirals

INTRODUCTION

Current antiretroviral therapy allows to achieve and sustain maximal suppression of HIV replication in most treated patients. As result, the life expectancy of HIV-infected persons has improved dramatically and is nowadays similar to that of the HIV-negative population. However, oral antiretrovirals have to be taken daily and indefinitely to avoid resumption of HIV replication and selection of drug resistance. Unfortunately, drug adherence is often suboptimal and tends to decline over time. Areas covered: New drugs, formulations and delivery systems are being developed for extended-release of antiretrovirals. At this time, intramuscular cabotegravir and rilpivirine, dapivirine vaginal rings and tenofovir alafenamide subdermal implants are the products in more advanced stages of clinical development. Their pharmacokinetics/dynamics and safety/efficacy are reviewed. Expert commentary: In the absence of eradicative therapy for individuals with HIV infection and protective vaccines for persons at risk, long-term antiretroviral therapy is the best approach for preventing disease progression in patients and halting transmissions, either as result of 'treatment as prevention' for HIV carriers or 'pre-exposure prophylaxis' for uninfected individuals at risk. In all these scenarios, the advent of long-acting antiretrovirals will expand options for overcoming the challenge of suboptimal drug adherence and reduce the burden of HIV infection.

Pre-exposure prophylaxis: awareness, acceptability and risk compensation behaviour among men who have sex with men and the transgender population

OBJECTIVES

This exploratory study examined the facilitators of and barriers to acceptance of pre-exposure prophylaxis (PrEP) and potential risk compensation behaviour emerging from its use among men who have sex with men (MSM) and transgender individuals (TGs) in India.

METHODS

A questionnaire was administered to 400 individuals registered with a targeted intervention programme. Logistic regression models were used to identify facilitators of and barriers to PrEP acceptance.

RESULTS

The respondents consisted of 68% MSM and 32% TGs. Risk behaviour categorization identified 40% as low risk, 41% as medium risk and, 19% as high risk for HIV infection. About 93% of the respondents were unaware of PrEP, but once informed about it, 99% were willing to use PrEP. The facilitators of PrEP acceptance were some schooling [odds ratio (OR) 2.16; P = 0.51], being married or in a live-in relationship (OR 2.08; P = 0.46), having a high calculated risk (OR 3.12; P = 0.33), and having a high self-perceived risk (OR 1.8; P = 0.35). Increasing age (OR 2.12; P = 0.04) was a significant barrier. TGs had higher odds of acceptance of PrEP under conditions of additional cost (OR 2.12; P = 0.02) and once-daily pill (OR 2.85; P = 0.04). Individuals identified as low risk for HIV infection showed lower odds of potential risk compensation, defined as more sexual partners (OR 0.8; P = 0.35), unsafe sex with new partners (OR 0.71; P = 0.16), and decreased condom use with regular partners (OR 0.95; P = 0.84), as compared with medium-risk individuals. The associations, although not statistically significant, are nevertheless important for public health action given the limited scientific evidence on PrEP use among MSM and TGs in India.

CONCLUSIONS

With high acceptability and a low likelihood of risk compensation behaviour, PrEP can be considered as an effective prevention strategy for HIV infection among MSM and TGs in India.

Willingness to Use Pre-Exposure Prophylaxis (PrEP): An Empirical Test of the Information-Motivation-Behavioral Skills (IMB) Model among High-Risk Drug Users in Treatment

Evidence from recent pre-exposure prophylaxis (PrEP) trials has demonstrated its safety and efficacy in significantly reducing the risk of HIV acquisition for those who are at considerable risk of acquiring HIV infection. With a rapid increase in the amount of research on the efficacy of PrEP for HIV prevention, complementary research on the willingness to use PrEP has grown, especially among MSM, but limited research has been focused among people who use drugs (PWUD). As part of the formative process, we utilized the information-motivation-behavioral skills (IMB) model of health behavior change to characterize and guide intervention development for promoting willingness to use PrEP among high-risk PWUD. The analysis included 400 HIV-negative high-risk PWUD enrolled in a community-based methadone maintenance treatment who reported drug- and/or sex-related HIV risk behaviors in the past 6-months. Analyses revealed support for the IMB model as PrEP-related behavioral skills were found to mediate the influence of PrEP-related information and motivation on willingness to use PrEP. The results provide evidence as to the utility of the IMB model to increase willingness to use PrEP among high-risk PWUD. It therefore makes an important contribution to our understanding of the applicability of theoretically-grounded models of willingness to use PrEP among high-risk PWUD, who are one of the key risk populations who could benefit from the use of PrEP.

Awareness and Acceptability of Pre-exposure HIV Prophylaxis Among Men Who have Sex with Men in Baltimore

This paper assessed characteristics associated with awareness of and willingness to take pre-exposure prophylaxis (PrEP) among Baltimore men who have sex with men (MSM). We used data from BESURE-MSM3, a venue-based cross-sectional HIV surveillance study conducted among MSM in 2011. Multivariate regression was used to identify characteristics associated with PrEP knowledge and acceptability among 399 participants. Eleven percent had heard of PrEP, 48% would be willing to use PrEP, and none had previously used it. In multivariable analysis, black race and perceived discrimination against those with HIV were significantly associated with decreased awareness, and those who perceived higher HIV discrimination reported higher acceptability of PrEP. Our findings indicate a need for further education about the potential utility of PrEP in addition to other prevention methods among MSM. HIV prevention efforts should address the link between discrimination and potential PrEP use, especially among men of color.

Pre- and post-sexual exposure prophylaxis of HIV: An update

Pitfalls in current HIV prevention strategies include late HIV testing, vulnerability among youth and females; lack of emphasis on treatment, low acceptance of circumcision, and nonavailability of protective vaccines. Continuing high-risk sexual behavior, forceful sex, coercive and nonconsensual sex, rape, and unprotected sexual activities make women the most vulnerable to acquisition of sexually transmitted infection/HIV and necessitates a more radical approach of prevention in high-risk individuals who do not have HIV. Preexposure prophylaxis is defined as the administration of antiretroviral drugs to an uninfected person before potential HIV exposure to reduce the risk of infection and continued during risk. The rationale of this approach is to administer preventive dose of drug(s) before exposure to HIV so the moment virus enters the body, HIV replication is inhibited and HIV is not able to establish permanent infection. Postexposure prophylaxis (PEP) following potential sexual exposure is an important form of nonoccupational PEP which is an emergency intervention to abort HIV acquisition arising from exposure to HIV-infected blood or potentially infectious bodily fluids following sexual exposure.

Past, Present, and Future Drug Delivery Systems for Antiretrovirals

The human immunodeficiency virus has infected millions of people and the epidemic continues to grow rapidly in some parts of the world. Antiretroviral (ARV) therapy has provided improved treatment and prolonged the life expectancy of patients. Moreover, there is growing interest in using ARVs to protect against new infections. Hence, ARVs have emerged as our primary strategy in combating the virus. Unfortunately, several challenges limit the optimal performance of these drugs. First, ARVs often require life-long use and complex dosing regimens. This results in low patient adherence and periods of lapsed treatment manifesting in drug resistance. This has prompted the development of alternate dosage forms such as vaginal rings and long-acting injectables that stand to improve patient adherence. Another problem central to therapeutic failure is the inadequate penetration of drugs into infected tissues. This can lead to incomplete treatment, development of resistance, and viral rebound. Several strategies have been developed to improve drug penetration into these drug-free sanctuaries. These include encapsulation of drugs in nanoparticles, use of pharmacokinetic enhancers, and cell-based drug delivery platforms. In this review, we discuss issues surrounding ARV therapy and their impact on drug efficacy. We also describe various drug delivery-based approaches developed to overcome these issues.

Knowledge, Attitudes, and Acceptability of Pre-Exposure Prophylaxis among Individuals Living with HIV in an Urban HIV Clinic

Introduction

Pre-exposure prophylaxis (PrEP) is an effective tool to reduce HIV transmission. The primary objective of this study was to assess awareness of PrEP by individuals living with HIV (HIV+) and acceptance of its use for their HIV negative (HIV-) partners.

Methods

A cross sectional survey was conducted among individuals living with HIV who received care at an urban HIV clinic between January 2013 and June 2013. The survey examined knowledge, attitudes, and acceptability of PrEP, and perception of transmission risk of HIV. Chi-Square test and Fisher's Exact test were used to compare proportions.

Results

Among 206 subjects living with HIV, 15.3% (32) had heard of PrEP. Men who have sex with men (MSM) were more likely to be aware of PrEP than all others (p = 0.003). Once educated about PrEP those who believed PrEP would reduce their partner’s risk for HIV were more likely to recommend PrEP to their partner (p<0.001). 92% of all respondents said they would be “extremely likely/likely” to discuss PrEP use with their provider. Of 159 subjects whose main partner was HIV-, MSM (p = 0.007), male participants (p = 0.044), and those who were consistently taking meds (p = 0.049) were more likely to be aware of PrEP. Those who perceived they were at risk of transmitting HIV (p<0.001) and those who were consistently taking meds (0.049) were more likely to agree that PrEP could reduce the risk of HIV to their partners.

Conclusion

This study illustrates a low awareness of PrEP but once educated the willingness of a cohort of individuals living with HIV to recommend PrEP to their partners. Our findings demonstrate the importance of providers informing their patients living with HIV about PrEP, as these persons are an underutilized link to support the uptake of PrEP by their HIV- partners.

HIV pre-exposure prophylaxis (PrEP): a review of current knowledge of oral systemic HIV PrEP in humans

PURPOSE

Despite established HIV prevention strategies and broadly available diagnostic strategies in developed western countries, rates of HIV new infections remain high. Alternative strategies for HIV prevention, particularly among men who have sex with men (MSM), are crucial. HIV pre-exposure prophylaxis (PrEP) has been discussed as one additional option that this review seeks to explore.

METHODS

An online search identifying PrEP-relevant literature from 1st January 2010 to 1st August, 2015 was performed.

RESULTS

The iPrEx study, first published in 2010, demonstrated a reduction in relative risk (RRR) of HIV seroconversion of 44 % for continuous PrEP with tenofovir disoproxil fumarate (TDF) and emtricitabine (FTC) in MSM. The efficacy of PrEP has been confirmed for continuous PrEP in the PROUD study and for intermittent PrEP in the IPERGAY study (RRR = 86 % in both studies). The PrEP was well tolerated in all studies, and the evolution of HIV resistance has been low. Compensatory increased sexual risk behavior was not observed in recent studies. In contrast to the high efficacy of risk reduction for HIV transmission in MSM, the results of TDF PrEP and TDF/FTC PrEP studies using microbicidal agents or pills among heterosexual women were different (RRR 6-75 %).

CONCLUSIONS

Continuous and intermittent PrEP demonstrated high efficacy in preventing HIV seroconversion, notably among MSM. PrEP was well tolerated. Adherence was critical for high efficacy in all studies. Further studies to evaluate implementation strategies and cost-effectiveness in different risk populations are needed as well as drug approval in Europe.

Combination HIV prevention interventions: the potential of integrated behavioral and biomedical approaches

Combination HIV prevention interventions that integrate efficacious behavioral and biomedical strategies offer the potential to reduce new HIV infections. We overview the efficacy data for three biomedical HIV prevention approaches, namely microbicides, pre-exposure prophylaxis (PrEP), and HIV vaccination; review factors associated with differential acceptability and uptake of these methods; and suggest strategies to optimize the effectiveness and dissemination of combination HIV prevention approaches. A narrative review was conducted highlighting key efficacy data for microbicides, PrEP, and an HIV vaccination and summarizing acceptability data for each of the three biomedical HIV prevention approaches. Recommendations for the integration and dissemination of combined behavioral and biomedical HIV prevention approaches are provided. To date, microbicides and an HIV vaccination have demonstrated limited efficacy for the prevention of HIV. However, PrEP has demonstrated efficacy in reducing HIV incident infections. A diverse array of factors influences both hypothetical willingness and actual usage of each biomedical prevention method. Strategies to effectively integrate and evaluate combination HIV prevention interventions are urgently needed.

Utilization of HIV prevention services across racial/ethnic groups among men who have sex with men in San Francisco, California, 2008

Human Immunodeficiency Virus (HIV) infection in the US is disproportionally higher among Black and Latino men who have sex with men (MSM), compared to other racial/ethnic groups. The 2008 US National HIV Behavioral Surveillance (NHBS) survey of MSM was analyzed to compare utilization of HIV testing, receiving condoms, and individual and group HIV prevention programs among racial/ethnic groups in San Francisco, CA. Using a weighted analysis of the time-location sampling method, racial/ethnic subpopulation estimates were obtained for utilization of these services in the prior 12 months. There was no significant difference in utilization of HIV prevention services among Black (N=37), Latino (N=128), and White (N=275) MSM in San Francisco, CA. Overall 60-70 % of MSM reported their last HIV test within the past 12 months and more than 75 % reported receiving condoms in the last 12 months. However, less than 15 % of MSM reported utilizing individual or group HIV prevention counseling sessions. The NHBS survey demonstrate that the majority of MSM in San Francisco, CA have utilized one or more HIV prevention service in the past 12 months and that there were no racial/ethnic disparities in utilization of these services. However, the utilization of individual or group HIV prevention programs is low and HIV testing is below current recommendations for MSM.

Systemic preexposure prophylaxis for HIV: translating clinical data to clinical practice

OBJECTIVE

To assess the real-world implications of oral tenofovir-emtricitabine (TDF-FTC) for HIV preexposure prophylaxis (PrEP) in clinical practice and highlight important considerations for its implementation.

DATA SOURCES

A search of PubMed (January 1996 through June 2013) was conducted using the terms HIV preexposure prophylaxis, HIV prevention, tenofovir, and emtricitabine. Abstracts from 2012-2013 HIV/AIDS conferences were also reviewed.

STUDY SELECTION AND DATA EXTRACTION

All pertinent original studies and review articles published in English were evaluated for inclusion. Reference citations from identified articles were examined for additional content.

DATA SYNTHESIS

Although antiretroviral therapy has been highly successful in reducing AIDS outcomes and death in HIV-infected patients worldwide, transmission of HIV remains a major global health problem. The recent approval of oral TDF-FTC for HIV PrEP represents the latest biomedical intervention to help control this epidemic. Four published randomized studies evaluated the efficacy and safety of this combination to prevent HIV transmission in several at-risk populations, including men who have sex with men, serodiscordant couples, and heterosexuals residing in endemic regions. Overall, these studies demonstrated significant risk reductions in the incidence of new HIV infections with good short-term tolerability. Despite promising results from clinical studies, several limitations may hinder the utility of PrEP in clinical practice. Most importantly, PrEP was studied in the context of a comprehensive prevention program, including intensive counseling on adherence, high-risk behaviors, and traditional preventative measures. If PrEP is implemented without these adjunct measures, concerns about failure and increased resistance may eventually be realized.

CONCLUSION

The greatest impact of PrEP, both clinically and financially, will likely arise from judicious application in select high-risk populations. If used appropriately, PrEP has the potential to augment reductions in the current incidence of new HIV infections, and pharmacists will have an important role in the careful selection and counseling of these targeted populations.

HIV among men who have sex with men in Malawi: elucidating HIV prevalence and correlates of infection to inform HIV prevention

Introduction

There are limited data characterizing the burden of HIV among men who have sex with men (MSM) in Malawi. Epidemiologic research and access to HIV prevention, treatment and care services have been traditionally limited in Malawi by criminalization and stigmatization of same-sex practices. To inform the development of a comprehensive HIV prevention intervention for Malawian MSM, we conducted a community-led assessment of HIV prevalence and correlates of infection.

Methods

From April 2011 to March 2012, 338 MSM were enrolled in a cross-sectional study in Blantyre, Malawi. Participants were recruited by respondent-driven sampling methods (RDS), reaching 19 waves. Trained staff administered the socio-behavioural survey and HIV and syphilis voluntary counselling and testing.

Results

Crude HIV and syphilis prevalence estimates were 15.4% (RDS-weighted 12.5%, 95% confidence interval (CI): 7.3–17.8) and 5.3% (RDS-weighted 4.4%, 95% CI: 3.1–7.6), respectively. Ninety per cent (90.4%, unweighted) of HIV infections were reported as being previously undiagnosed. Participants were predominantly gay-identified (60.8%) or bisexually identified (36.3%); 50.7% reported recent concurrent relationships. Approximately half reported consistent condom use (always or almost always) with casual male partners, and proportions were relatively uniform across partner types and genders. The prevalence of perceived and experienced stigma exceeded 20% for almost all variables, 11.4% ever experienced physical violence and 7% were ever raped. Current age >25 years (RDS-weighted adjusted odds ratio (AOR) 3.9, 95% CI: 1.2–12.7), single marital status (RDS-weighted AOR: 0.3; 95% CI: 0.1–0.8) and age of first sex with a man <16 years (RDS-weighted AOR: 4.3, 95% CI: 1.2–15.0) were independently associated with HIV infection.

Conclusions

Results demonstrate that MSM represent an underserved, at-risk population for HIV services in Malawi and merit comprehensive HIV prevention services. Results provide a number of priorities for research and prevention programmes for MSM, including providing access to and encouraging regular confidential HIV testing and counselling, and risk reduction counselling related to anal intercourse. Other targets include the provision of condoms and compatible lubricants, HIV prevention information, and HIV and sexually transmitted infection treatment and adherence support. Addressing multiple levels of HIV risk, including structural factors, may help to ensure that programmes have sufficient coverage to impact this HIV epidemic among MSM.

Interventions to address HIV and intimate partner violence in Sub-Saharan Africa: a review of the literature

HIV and intimate partner violence (IPV) are commonly co-occurring epidemics affecting the health of women globally and especially in sub-Saharan Africa. There is a need for interventions that address both HIV and IPV in health care settings. Our review examined recent literature for intervention studies that explored both HIV and IPV. Of the nine interventions identified, only two were set in health care settings; the remainder were community based. Large multifaceted community-based interventions showed promise in the areas of addressing social norms in order to empower women. Educational interventions have shown short-term improvements in HIV-related knowledge and behavioral intention. Further research is needed to examine brief screening, intervention, and referral for HIV and IPV services within health care settings. Health care-specific interventions such as use of preexposure and postexposure prophylaxis to prevent HIV transmission must also be studied in the context of IPV.

Access to Basic HIV-Related Services and PrEP Acceptability among Men Who Have sex with Men Worldwide: Barriers, Facilitators, and Implications for Combination Prevention

Introduction. Men who have sex with men (MSM) are disproportionately impacted by HIV globally. Easily accessible combination HIV prevention strategies, tailored to the needs of MSM, are needed to effectively address the AIDS pandemic. Methods and Materials. We conducted a cross-sectional study among MSM (n = 3748) from 145 countries from April to August 2012. Using multivariable random effects models, we examined factors associated with acceptability of preexposure prophylaxis (PrEP) and access to condoms, lubricants, HIV testing, and HIV treatment. Results. Condoms and lubricants were accessible to 35% and 22% of all respondents, respectively. HIV testing was accessible to 35% of HIV-negative respondents. Forty-three percent of all HIV-positive respondents reported that antiretroviral therapy was easily accessible. Homophobia, outness, and service provider stigma were significantly associated with reduced access to services. Conversely, community engagement, connection to gay community, and comfort with service providers were associated with increased access. PrEP acceptability was associated with lower PrEP-related stigma, less knowledge about PrEP, less outness, higher service provider stigma, and having experienced violence for being MSM. Conclusions. Ensuring HIV service access among MSM will be critical in maximizing the potential effectiveness of combination approaches, especially given the interdependence of both basic and newer interventions like PrEP. Barriers and facilitators of HIV service access for MSM should be better understood and addressed.

Estimating the efficacy of preexposure prophylaxis for HIV prevention among participants with a threshold level of drug concentration

Assays for detecting levels of antiretroviral drugs in study participants are increasingly popular in preexposure prophylaxis (PrEP) trials, since they provide an objective measure of adherence. Current correlation analyses of drug concentration data are prone to bias. In this article, we formulate the causal estimand of prevention efficacy among drug compliers, those who would have had a threshold level of drug concentration had they been assigned to the drug arm of the trial. The identifiability of the causal estimand is facilitated by exploiting the exclusion restriction; that is, drug noncompliers do not acquire any prevention benefit. In addition, we develop an approach to sensitivity analysis that relaxes the exclusion restriction. Applications to published data from 2 PrEP trials, namely the Preexposure Prophylaxis Initiative (iPrEx) trial and the Centre for the AIDS Programme of Research in South Africa (CAPRISA) 004 trial, suggest high efficacy estimates among drug compliers (in the iPrEx trial, odds ratio = 0.097 (95% confidence interval: 0.027, 0.352); in the CAPRISA 004 trial, odds ratio = 0.104 (95% confidence interval: 0.024, 0.447)). In summary, the proposed inferential method provides an unbiased assessment of PrEP efficacy among drug compliers, thus adding to the primary intention-to-treat analysis and correlation analyses of drug concentration data.

Are Thai MSM willing to take PrEP for HIV prevention? An analysis of attitudes, preferences and acceptance

OBJECTIVE

We aimed to understand the attitudes, preferences and acceptance of oral and parenteral PrEP among men who have sex with men (MSM) in Thailand.

BACKGROUND

Pre-exposure prophylaxis (PrEP), the use of antiretrovirals to prevent HIV acquisition, has shown promising results in recent trials. To assess the potential impact of this new HIV prevention method, in addition to efficacy data, we need to understand which psychosocial factors are likely to determine its uptake among members of potential user groups.

METHODS AND FINDINGS

Surveys of willingness to use PrEP products were administered to MSM. Spearman's rank tests were used to uncover associations between questionnaire items. Mann-Whitney tests were performed to ascertain differences between groups. Conjoint analysis was used to examine the attitudes and preferences of MSM towards PrEP attributes. Most participants were willing to consider taking PrEP (39.2% "yes, definitely" and 49.2% "yes, probably") and perceived PrEP as giving them new possibilities in their lives (38.5% "a lot of hope" and 55.8% "some hope"), even after being instructed of potential side effects and costs. HIV testing was considered the most important attribute and a daily pill and longer lasting injection in the arm were the preferred routes of administration.

CONCLUSIONS

Despite its multiple challenges, MSM in Thailand would be willing to take PrEP, even if they had to experience inconvenience and expense. If PrEP were to be implemented in Thailand, our findings show that its uptake could be considerable.

Pharmacists as providers of HIV pre-exposure prophylaxis

The efficacy of HIV pre-exposure prophylaxis (PrEP) has been demonstrated in four clinical trials to date; however, the success of PrEP is largely dependent on high levels of medication adherence. Due to their extensive experience and expertise in medication adherence counseling, as well as their ability to monitor and manage medication adverse effects and drug-drug interactions, clinical pharmacists are well-equipped to play a key role in effective PrEP utilization. Here we discuss reasons favoring the establishment of a protocol-based, pharmacist-run PrEP clinic.

HIV in Africa: Challenges and Directions for the Next Decade

Africa carries a disproportionate burden of the global HIV endemic, accounting for two thirds of the global 33.3 million people living with HIV. While tremendous advances have been made in addressing the HIV epidemic in Africa, considerable challenges remain. Testing for HIV increased by 86% from 2007 to 2009 but more than 75% of people 15-49 years remain unaware of their HIV status. CD4 count at diagnosis tends to be low and linkage to care and treatment is suboptimal. The scale-up of antiretroviral therapy is ongoing but is hampered by the lack of diagnostic capability to monitor response to therapy and a substantial healthcare workforce shortage. Prevention strategies such as male circumcision, pre-exposure prophylaxis, and antiretroviral therapy for prevention have generated great excitement but cost and healthcare infrastructure deficiencies may limit their widespread applicability. Operational research to validate and inform treatment decisions, health care policies, and prevention strategies is sorely needed.

Evaluating safer conception options for HIV-serodiscordant couples (HIV-infected female/HIV-uninfected male): a closer look at vaginal insemination

HIV serodiscordant couples represent at least half of all HIV-affected couples worldwide. Many of these couples have childbearing desires. Safer methods of conception may allow for pregnancy while minimizing the risk of sexual transmission of HIV. In serodiscordant partnerships with an HIV-infected female and HIV-uninfected male, vaginal insemination of a partner's semen during the fertile period coupled with 100% condom use may be the safest method of conception.

A qualitative study of provider thoughts on implementing pre-exposure prophylaxis (PrEP) in clinical settings to prevent HIV infection

Background

A recent clinical trial demonstrated that a daily dose tenofovir disoproxil fumarate and emtricitabrine (TDF-FTC) can reduce HIV acquisition among men who have sex with men (MSM) and transgender (TG) women by 44%, and up to 90% if taken daily. We explored how medical and service providers understand research results and plan to develop clinical protocols to prescribe, support and monitor adherence for patients on PrEP in the United States.

Methods

Using referrals from our community collaborators and snowball sampling, we recruited 22 healthcare providers in San Francisco, Oakland, and Los Angeles for in-depth interviews from May-December 2011. The providers included primary care physicians seeing high numbers of MSM and TG women, HIV specialists, community health clinic providers, and public health officials. We analyzed interviews thematically to produce recommendations for setting policy around implementing PrEP. Interview topics included: assessing clinician impressions of PrEP and CDC guidance, considerations of cost, office capacity, dosing schedules, and following patients over time.

Results

Little or no demand for PrEP from patients was reported at the time of the interviews. Providers did not agree on the most appropriate patients for PrEP and believed that current models of care, which do not involve routine frequent office visits, were not well suited for prescribing PrEP. Providers detailed the need to build capacity and were concerned about monitoring side effects and adherence. PrEP was seen as potentially having impact on the epidemic but providers also noted that community education campaigns needed to be tailored to effectively reach specific vulnerable populations.

Conclusions

While PrEP may be a novel and clinically compelling prevention intervention for MSM and TG women, it raises a number of important implementation challenges that would need to be addressed. Nonetheless, most providers expressed optimism that they eventually could prescribe and monitor PrEP in their practice.

Stampidine as a promising antiretroviral drug candidate for pre-exposure prophylaxis against sexually transmitted HIV/AIDS

INTRODUCTION

Pre-exposure prophylaxis (PrEP) is an evolving new approach to prevention of sexually transmitted HIV-1 that employs antiretroviral (ARV) agents prior to potential HIV-1 exposure in an attempt to reduce the likelihood of HIV-1 infection postexposure. The identification of new ARV agents with potent activity against multidrug-resistant HIV remains an unmet and urgent challenge in the field of PrEP.

AREAS COVERED

This article reviews the preclinical and early clinical activity and safety profile of stampidine, a novel antiretroviral (ARV) drug candidate that exhibits remarkable subnanomolar to low nanomolar in vitro antiretroviral potency against genotypically and phenotypically nucleoside reverse transcriptase inhibitor (NRTI)-resistant primary clinical HIV isolates, non-nucleoside RT-resistant HIV-1 isolates. Stampidine has a favorable pharmacokinetic profile in mice, rats, dogs and cats with 25 or 50 mg/kg tolerable dose levels yielding micromolar plasma concentrations that are 1000-fold higher than its in vitro IC(50) value against HIV. Stampidine has a favorable, safety profile in mice, rats, dogs and cats and it showed significant in vivo ARV activity in HIV-infected Hu-PBL-SCID mice as well as FIV-infected domestic cats. Furthermore, it did not cause any maternal toxicity, developmental toxicity or teratogenicity in rabbits treated at 10 - 40 mg/kg/day dose levels. In a recently completed first-in-human Phase I clinical trial, stampidine did not cause dose-limiting toxicity at single dose levels ranging from 5 to 25 mg/kg.

EXPERT OPINION

The favorable safety and activity profile of stampidine warrants its further development as a promising next-generation PrEP candidate to prevent the sexual transmission of HIV-1. The discovery of stampidine as a potent antiretroviral agent represents a significant step forward in the development of effective therapeutic as well as preventive strategies against HIV/AIDS.

The use of preexposure treatments for HIV prophylaxis

Infection with human immunodeficiency virus remains a global concern with a significant number of incident infections still reported worldwide. The use of prophylaxis prior to exposure to the virus to prevent infection has been a growing area of recent research. Results in nonhuman primates and clinical trials in high-risk patient populations using preexposure prophylaxis have shown promising results in terms of efficacy and safety, especially relating to oral preexposure prophylaxis. The potential use of oral antiretroviral agents traditionally used for human immunodeficiency virus treatment as prophylaxis raises interesting considerations, such as the best agents available for such a role, long-term safety in healthy individuals, and the potential development of resistance to these agents should infection occur. From a public health perspective, the cost-effectiveness of implementing this preventive strategy has not been fully defined at this point in time.

Prevention interventions for human immunodeficiency virus in drug-using women with a history of partner violence

The intersecting epidemics of human immunodeficiency virus (HIV) and partner violence disproportionately affect women who use drugs. Despite accumulating evidence throughout the world linking these epidemics, HIV prevention efforts focused on these synergistic issues as well as underlying determinants that contribute to the HIV risk environment (eg, housing instability, incarceration, policing practices, survival sex) are lacking. This article highlights selected behavior change theories and biomedical approaches that have been used or could be applied in HIV prevention interventions for drug-using women with histories of partner violence and in existing HIV prevention interventions for drug-using women that have been gender-focused while integrating histories of partner violence and/or relationship power dynamics. To date, there is a paucity of HIV prevention interventions designed for drug-using women (both in and outside of drug treatment programs) with histories of partner violence. Of the few that exist, they have been theory-driven, culture-specific, and address certain aspects of gender-based inequalities (eg, gender-specific norms, relationship power and control, partner violence through assessment of personal risk and safety planning). However, no single intervention has addressed all of these issues. Moreover, HIV prevention interventions for drug-using women with histories of partner violence are not widespread and do not address multiple components of the risk environment. Efficacious interventions should target individuals, men, couples, and social networks. There is also a critical need for the development of culturally tailored combination HIV prevention interventions that not only incorporate evidence-based behavioral and biomedical approaches (eg, microbicides, pre-exposure prophylaxis, female-initiated barrier methods) but also take into account the risk environment at the physical, social, economic and political levels. Ultimately, this approach will have a significant impact on reducing HIV infections among drug-using women with histories of partner violence.

Attitudes and acceptance of oral and parenteral HIV preexposure prophylaxis among potential user groups: a multinational study

BACKGROUND

The use of antiviral medications by HIV negative people to prevent acquisition of HIV or pre-exposure prophylaxis (PrEP) has shown promising results in recent trials. To understand the potential impact of PrEP for HIV prevention, in addition to efficacy data, we need to understand both the acceptability of PrEP among members of potential user groups and the factors likely to determine uptake.

METHODS AND FINDINGS

Surveys of willingness to use PrEP products were conducted with 1,790 members of potential user groups (FSWs, MSM, IDUs, SDCs and young women) in seven countries: Peru, Ukraine, India, Kenya, Botswana, Uganda and South Africa. Analyses of variance were used to assess levels of acceptance across different user groups and countries. Conjoint analysis was used to examine the attitudes and preferences towards hypothetical and known attributes of PrEP programs and medications. Overall, members of potential user groups were willing to consider taking PrEP (61% reported that they would definitely use PrEP). Current results demonstrate that key user groups in different countries perceived PrEP as giving them new possibilities in their lives and would consider using it as soon as it becomes available. These results were maintained when subjects were reminded of potential side effects, the need to combine condom use with PrEP, and for regular HIV testing. Across populations, route of administration was considered the most important attribute of the presented alternatives.

CONCLUSIONS

Despite multiple conceivable barriers, there was a general willingness to adopt PrEP in key populations, which suggests that if efficacious and affordable, it could be a useful tool in HIV prevention. There would be a willingness to experience inconvenience and expense at the levels included in the survey. The results suggest that delivery in a long lasting injection would be a good target in drug development.