Divergent adherence estimates with pharmacokinetic and behavioural measures in the MTN-003 (VOICE) study

Pharmacologic Drug Detection and Self-Reported Adherence in the HPTN069/ACTG5305 Phase II PrEP Trial

Adherence drives efficacy in PrEP clinical trials. We compared drug concentrations and self-reported adherence in HPTN069/ACTG5305, a double-blinded, randomized trial of the safety and tolerability of candidate PrEP regimens that included maraviroc (MVC), tenofovir (TDF), and emtricitabine (FTC). Plasma drug concentrations and self-reported adherence by computer-assisted self-interview (CASI) were assessed at study weeks 24 and 48. Descriptive statistics and a generalized linear model were used to assess the association between selected demographic factors, self-report of daily medication adherence and plasma drug concentrations consistent with daily adherence. Among 718 paired observations from 370 participants, 43% (306/718) reported daily adherence by CASI, 65% (467/718) had drug concentrations consistent with daily adherence and 11% (81/718) had CASI responses that reported daily adherence despite having drug concentrations consistent with less-than-daily adherence. In adjusted analyses, participants who were assigned male at birth (aOR 1.42 [95% CI 1.02, 1.97]), older (5-year increments aOR 1.10 [95% CI 1.09, 1.11]), White (aOR 2.2 [95% CI 1.88, 2.56]), had advanced education (aOR 3.89 [95% CI 2.97, 5.09]), were employed (aOR 1.89 [95% CI 1.50, 2.40]), or partnered/married (aOR 2 [95% CI 1.72, 2.32]) were more likely to have drug concentrations consistent with daily adherence. Participants who were not employed (aOR 2.7 [95% CI 1.31, 5.55]) or who were single/not partnered (aOR 2.33 [CI 95% 1.25, 4.34]) were more likely to have drug concentrations that did not reflect daily adherence despite self-reported PrEP adherence. These findings support the need for ongoing adherence counseling in clinical trials of new PrEP regimens.

Pilot Randomized Controlled Trial of Game Plan for PrEP: A Brief, Web and Text Message Intervention to Help Sexual Minority Men Adhere to PrEP and Reduce Their Alcohol Use

Suboptimal adherence to oral PrEP medications, particularly among younger sexual minority men (SMM), continues to be a key barrier to achieving more substantial declines in new HIV infections. Although variety of interventions, including web and text-message-based applications, have successfully addressed PrEP adherence, very few have addressed the potential influence of alcohol. This pilot study explored whether the Game Plan for PrEP, a brief, web-based and text messaging intervention, helped promote PrEP persistence and adherence and reduced condomless sex and alcohol use. Seventy-three heavy-drinking SMM on PrEP were recruited online from states with Ending the HIV Epidemic jurisdictions and randomly assigned 1:1 to receive either the Game Plan for PrEP intervention or an attention-matched control. We collected online surveys assessing primary outcomes at one, three, and six months post-enrollment. As secondary outcomes, we also collected dried blood spot samples at baseline, three, and six months to analyze for biomarkers of PrEP and alcohol use. Our results showed that the odds of stopping PrEP or experiencing a clinically meaningful lapse in PrEP adherence (≥ 4 consecutive missed doses) were not different across the two conditions. We also did not find evidence of any differences in condomless sex or drinking outcomes across conditions, although participants in both conditions reported drinking less often over time. These findings were consistent across both self-reported outcomes and biomarkers. Overall, we did not find evidence that our brief, web and text messaging intervention encouraged more optimal PrEP coverage or moderate their alcohol use.

Effectiveness of a Community Empowerment Intervention to Improve Access to Pre-exposure Prophylaxis in Migrant Women Sex Workers: Protocol for a Mixed Methods Implementation Study

BACKGROUND

The World Health Organization recommends pre-exposure prophylaxis (PrEP) for all populations at substantial risk of HIV infection. However, at-risk women very rarely use PrEP in France-this represents a critical issue among migrant women sex workers (MWSWs). Previous studies on PrEP use among women sex workers or migrants focused on individual or social determinants of motivation. However, operational studies in real-word settings using a holistic population approach to maximize PrEP adherence among MWSWs are lacking.

OBJECTIVE

FASSETS (ie, "Favoriser l'Accès à la Santé Sexuelle des Travailleuses du Sexe"; English: "facilitate the access to Sexual Health in women sex workers") is a participative, multilevel, mixed methods study aiming to improve global knowledge of and access to sexual health care and PrEP among MWSWs through targeted empowerment strategies.

METHODS

This study comprises several phases: (1) phase 1: an initial qualitative study combining semistructured interviews, informal interviews, and participative observations will be performed among MWSWs, local community nongovernmental organizations, and institutions providing sexual reproductive health services to identify the determinants of PrEP access among MWSWs and for respondent-driven sampling (RDS); (2) phase 2: the size of the hidden MWSW population is estimated in Marseille through capture-recapture (the RDS survey will serve as "recapture"); (3) phase 3: a longitudinal cohort will be formed through RDS to represent the MWSW population with a goal of 150 inclusions-this cohort will be followed up for 12 months, and sequential questionnaires exploring medical history; knowledge of sexual health, HIV, and sexually transmitted infections; migration route; and current living conditions will be administered at inclusion (month 0) and months 3, 6, and 12 to measure the following interventional phase's outcomes; and (4) phase 4: an interventional study with community empowerment actions about sexual health and PrEP will be conducted with community health workers; standardized questionnaires and semistructured interviews, observations, and focus groups will highlight MWSWs' experiences with empowerment resources, concerns about sexual health, and especially PrEP use or uptake, and we will evaluate whether and how community-adapted empowerment actions conducted by community health workers are effective in increasing access to sexual health, prevention and screening of sexually transmitted infections, and PrEP knowledge and access among MWSWs.

RESULTS

Recruitment commenced on March 1, 2022. We estimate the follow-up period to end on September 30, 2023.

CONCLUSIONS

This multiphase study will provide robust evidence about the magnitude of the MWSW population in Marseille (the second largest town in France) and their current conditions of living, access to and knowledge of sexual health, and PrEP access. Using a mixed methods analysis, we will investigate whether individual and collective community health empowerment approaches can facilitate access to PrEP and its initiation, use, and adherence in this vulnerable population.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/42844.

Strengthening the HIV prevention cascade to maximise epidemiological impact in eastern Zimbabwe: a modelling study

BACKGROUND

HIV prevention cascades provide a systematic understanding of barriers to prevention. In this study we used mathematical modelling to understand the consequences of these barriers and how the cascade could be strengthened to maximise epidemiological impact, providing potentially important insights for programmes.

METHODS

We used an individual-based model of HIV transmission (PopART-IBM), calibrated to data from the Manicaland cohort from eastern Zimbabwe. HIV prevention cascade estimates from this cohort were used as probabilities for indicators in the model representing an individual's motivation, access, and capacity to effectively use pre-exposure prophylaxis, voluntary male medical circumcision, and condoms. We examined how current barriers affect the number and distribution of HIV infections compared with a no-barrier scenario. Using assumptions about how interventions could strengthen the HIV prevention cascade, we estimated the reduction in HIV infections over a 10-year period through addressing different elements of the cascade.

FINDINGS

21 200 new potentially avertable HIV infections will occur over the next 10 years due to existing HIV prevention cascade barriers, 74·2% of the 28 500 new infections that would occur with existing barriers in a population of approximately 1·2 million adults. Removing these barriers would reduce HIV incidence below the benchmarks for epidemic elimination. Addressing all cascade steps in one priority population is substantially more effective than addressing one step across all populations.

INTERPRETATION

Interventions exist in eastern Zimbabwe to reduce HIV towards elimination, but barriers of motivation, access, and effective use prevent their full effect being realised. Interventions need to be multilayered and address all steps along the HIV prevention cascade. Models incorporating the HIV prevention cascade can help to identify the main barriers to greater effectiveness.

FUNDING

National Institutes of Mental Health, Bill & Melinda Gates Foundation, and Medical Research Council Centre for Global Infectious Disease Analysis funding from the UK Medical Research Council and UK Foreign, Commonwealth & Development Office (FCDO).

Dynamics of Pre-Exposure (PrEP) Eligibility Because of Waxing and Waning of HIV Risk in Rakai, Uganda

BACKGROUND

We conducted a retrospective population-based study to describe longitudinal patterns of prevalence, incidence, discontinuation, resumption, and durability of substantial HIV risk behaviors (SHR) for pre-exposure prophylaxis (PrEP) eligibility.

METHODS

The study was conducted among HIV-negative study participants aged 15-49 years who participated in survey rounds of the Rakai Community Cohort Study between August 2011 and June 2018. Substantial HIV risk was defined based on the Uganda national PrEP eligibility as reporting sexual intercourse with >1 partner of unknown HIV status, nonmarital sex without a condom, having genital ulcers, or having transactional sex. Resumption of SHR meant resuming of SHR after stopping SHR, whereas persistence of SHR meant SHR on >1 consecutive visit. We used generalized estimation equations with log-binomial regression models and robust variance to estimate survey-specific prevalence ratios; Generalized estimation equations with modified Poisson regression models and robust variance to estimate incidence ratios for incidence, discontinuation, and resumption of PrEP eligibility.

FINDINGS

Incidence of PrEP eligibility increased from 11.4/100 person-years (pys) in the first intersurvey period to 13.9/100 pys (adjusted incidence rate ratios = 1.28; 95%CI = 1.10-1.30) and declined to 12.6/100 pys (adjusted incidence rate ratios = 1.06; 95%CI = 0.98-1.15) in the second and third intersurvey periods, respectively. Discontinuation rates of SHR for PrEP eligibility were stable (ranging 34.9/100 pys-37.3/100 pys; P = 0.207), whereas resumption reduced from 25.0/100 pys to 14.5/100 pys ( P < 0.001). PrEP eligibility episodes lasted a median time of 20 months (IQR = 10-51).

INTERPRETATION

Pre-exposure prophylaxis use should be tailored to the dynamic nature of PrEP eligibility. Preventive-effective adherence should be adopted for assessment of attrition in PrEP programs.

Oral pre-exposure prophylaxis uptake, adherence, and adverse events among South African men who have sex with men and transgender women

Background

HIV prevention programmes that include pre-exposure prophylaxis (PrEP) for men who have sex with men (MSM) and transgender women (TGW) in South Africa have not been widely implemented.

Objectives

The authors examined oral PrEP uptake, adherence, and adverse events among HIV-uninfected MSM and TGW to inform intervention acceptability and feasibility.

Method

In 2015, MSM and TGW in two South African cities were offered a comprehensive package of HIV prevention services, including daily oral PrEP, and were followed for one year. Different models of PrEP delivery were used at each site. Adherence was measured using self-report and pill-count data and tenofovir-diphosphate (TFV-DP) concentrations.

Results

Among 135 participants who were eligible for PrEP, 82 (61%) initiated PrEP, of whom 67 (82%) were on PrEP at study end. Participants were on PrEP for a median of 294 out of 314.5 possible days (93% protected days). The median time from PrEP initiation to discontinuation or study end was 305 days (interquartile range: 232-325 days). Across the follow-up time points, 57% - 72% of participants self-reported taking protective levels of PrEP and 59% - 74% were adherent to PrEP as indicated by pill counts. Fewer (≤ 18%) achieved protective TFV-DP concentrations of ≥ 700 fmol/punch in dried blood spots. Side effects, while typically mild, were the most commonly cited reason by participants for early PrEP discontinuation.

Conclusion

Many MSM and TGW initiated and maintained PrEP, demonstrating that PrEP can be successfully delivered to South African MSM and TGW in diverse programmatic contexts. Biologic adherence measures suggest MSM and TGW may experience challenges taking PrEP regularly. Counselling for coping with side effects and motivating daily pill taking is recommended to support South African MSM and TGW in achieving protection with PrEP.

Cultivating PEARL (Promoting Empowerment and Risk Reduction): Formative Research for a PrEP Intervention Among Female Sex Workers in Baltimore, Maryland

Pre-exposure prophylaxis (PrEP) is a vital component of comprehensive HIV prevention among female sex workers (FSW). There are limited PrEP interventions targeting FSW in the U.S., who have high HIV risk. Formative research was conducted to inform PEARL (Promoting Empowerment And Risk Reduction), a PrEP intervention for FSW in Baltimore, MD, including a community forum, key informant interviews with providers, and focus group discussions with FSW. FSW and providers acknowledged challenges to building rapport and establishing continuity in care settings. FSW reported low PrEP awareness, with high interest once aware. FSW and providers reported uptake barriers including perceived financial issues, lack of PrEP awareness, and mistrust of the pharmaceutical industry. Concerns were raised about substance use and daily PrEP adherence. Developing a tailored PrEP intervention for FSW necessitates multiple perspectives (e.g. FSW, service providers). Resumen La profilaxis preexposición (PrEP) es un componente vital de la prevención integral del VIH para las trabajadoras sexuales (TSF). En los Estados Unidos, hay pocas intervenciones de PrEP dirigidas a las TSF, quienes experiencian un riesgo elevado de contraer el VIH. Se realizó una investigación formativa para informar a PEARL (Promoción del empoderamiento y la reducción de riesgos), una intervención de PrEP para TSF en Baltimore, MD-la cual incluyó un foro comunitario, entrevistas con proveedores de servicios a las TSF y discusiones entre grupos focales de TSF. TSF y proveedores de servicio reconocieron los retos de mantener buenas relaciones y establecer continuidad en los servicios de salud. TSF exhibieron conocimiento limitado sobre la PrEP, pero expresaron gran interés en la PrEP después de estar informadas. TSF y los proveedores de servicios hablaron de barreras aceptando a la PrEP, incluyendo problemas financieros percibidos, falta de conocimiento sobre la PrEP y desconfianza en la industria farmacéutica. Se expresaron preocupaciones sobre el uso de sustancias y la adherencia diaria a la PrEP. El desarrollo de una intervención de PrEP personalizada para TSF requiere varias perspectivas (por ejemplo, TSF, proveedores de servicios).

Drug-releasing vaginal rings for HIV/STI and pregnancy prevention: A review of recent advances and clinical applications

INTRODUCTION

Adolescent girls and young women (AGYW), as well as pre- and post-menopausal women globally would benefit from expanded choice to address their sexual and reproductive health (SRH) needs related to Human Immunodeficiency Virus (HIV), sexually transmitted infections (STIs) and pregnancy prevention. Lack of adequate preventative vaccines for HIV/STIs reinforces public health prioritization for options women may use independently to mitigate risk for infectious disease and unplanned pregnancy. Drug releasing intravaginal rings (IVR) represent one such technology that has garnered attention based on the modality's success recently as a pre-exposure prophylaxis (PrEP) delivery option and its impact on reduction in HIV risk.

AREAS COVERED

: This article provides a synopsis of three IVR technologies in active clinical development for prevention of HIV, STI, and unintended pregnancy demonstrating advancements in terms of compatibility with a wide range of drug types with a focus on dapivirine-based silicone rings (International Partnership for Microbicides (IPM), tenofovir-based polyurethane rings (CONRAD), and pod-based rings (Oak Crest Institute of Science).

EXPERT OPINION

The goals of IVR research are to reduce burdens of HIV/STIs and unplanned pregnancies. Through the evolution of IVR technologies, the potential exists to trigger integration of healthcare services through formulation of products with multiple indications.

The Influence of Perceived Dapivirine Vaginal Ring Effectiveness on Social Disclosure and Ring Adherence

We analyzed data from 1428 users of the dapivirine vaginal ring, who participated in the MTN-020/ASPIRE phase III trial and subsequent open-label extension MTN-025/HOPE trial, to examine relationships between perceived ring protection, social disclosures, and self-reported ring adherence. In HOPE, 77% perceived the ring to be highly effective, and this view was associated with speaking: (a) to a greater number of people about the study, (b) with other participants, (c) to more people who were in favor of the ring, and (d) to more people whose opinions were valued. Reported adherence was not directly associated with perceived protection but was associated with disclosing to someone who was in favor of the ring. These findings suggest the importance of women's internalized ideas about the protective benefits of the DVR in sharing information about the ring and the importance of social support on adherence.

Brief Report: Discrepancies Between Self-Reported Adherence and a Biomarker of Adherence in Real-World Settings

BACKGROUND

Pre-exposure prophylaxis (PrEP) is only effective in preventing new HIV infections when taken consistently. In clinical practice, asking a patient about their adherence (self-report) is the predominant method of assessing adherence to PrEP. Although inexpensive and noninvasive, self-report is subject to social desirability and recall biases. Several clinical trials demonstrate a discrepancy between self-reported adherence and biomarker-based recent adherence. Less is known about the accuracy of self-report in real-world clinical settings. This brief report addresses this knowledge gap and describes the concordance between self-reported adherence and biomarker-based adherence in real-world clinical settings.

METHODS

A liquid chromatography-mass spectrometry urine test for tenofovir was developed and used clinically to detect recent nonadherence (no dose in at least 48 hours) for each individual. Two clinics' standard operating procedures recommend utilization of the urine-based adherence test for patients who self-report that they are not struggling with adherence. Those who self-report struggling with adherence receive enhanced adherence support without the need for additional testing. The number of results indicating recent nonadherence from these 2 clinics were analyzed to assess the concordance between self-reported adherence and biomarker-based adherence.

RESULTS

Across 2 clinics, 3987 tests were conducted from patients self-reporting as "adherent," and 564 [14.1%; 95% confidence interval (CI): 13.1% to 15.2%] demonstrated recent nonadherence with the liquid chromatography-mass spectrometry test. At clinic #1 in Florida, 3200 tests were conducted, and 465 (14.5%; 95% CI: 13.3% to 15.8%) demonstrated recent nonadherence. At clinic #2 in Texas, 787 tests were conducted, and 99 (12.6%; 95% CI: 10.4% to 14.9%) demonstrated recent nonadherence.

CONCLUSIONS

Utilization of biomarker-based adherence monitoring at these 2 clinics resulted in 564 additional patients receiving enhanced adherence support who otherwise would not have been identified as nonadherent to their prescribed PrEP regimen. These findings suggest that objective adherence monitoring can be used clinically to enable providers to identify nonadherent patients and allocate support services accordingly.

The effectiveness of tenofovir-based pre-exposure prophylaxis for prevention of HIV acquisition among sub-Saharan African women at high risk: a systematic review

Introduction

women in sub-Saharan Africa (SSA) are disproportionately affected by the HIV epidemic. In 2019, they constituted 59% of new infections; thus, they remain a key population for control. Public health interventions to prevent acquisition of HIV in this high-risk population are urgently needed. Tenofovir-based pre-exposure prophylaxis (TFV-PrEP) has been shown to reduce HIV infections in other key populations. However, comprehensive evidence regarding TFV-PrEP effectiveness in women living in SSA has not been determined. Therefore, we undertook a systematic review to determine the effectiveness of tenofovir-1% (TFV-1%) vaginal gel, oral tenofovir (TFV) and tenofovir-emtricitabine (TDF-FTC) pre-exposure prophylaxis for primary acquisition of HIV in at-risk women living in SSA.

Methods

OVID Medline, Embase, CENTRAL, Web of Science and Clinical Trials.gov were searched for eligible studies from 1^st January 2020 to 31^st July 2020. Only randomised controlled trials (RCTs) conducted in women living in SSA were included. Measures of effectiveness (hazard ratios (HR), incidence rate ratios (IRR)) were extracted from individual studies to determine the effectiveness of TFV-PrEP in preventing HIV infection among at-risk women living in SSA.

Results

from 2002 non-duplicate articles, four RCTs evaluating the effectiveness of one or more of the interventions against placebos were included. TFV-1% vaginal gel, oral TDF or TDF-FTC were not effective in preventing the acquisition of HIV infection in women living in SSA. However, poor adherence by study participants could have confounded the true effectiveness of TFV-PrEP in this high risk population. Meta-analysis was not conducted given the limited number of eligible studies identified from the search.

Conclusion

the current evidence does not support the effectiveness of TFV-PrEP for HIV in SSA women. More studies aimed at addressing factors driving low adherence to HIV interventions in this high risk population are urgently needed in order to improve the design of future RCTs leading to the determination of more reliable estimates of TFV-1% vaginal gel or oral TDF or TDF-FTC effectiveness. Protocol registration: this systematic review was not registered in PROSPERO.

Characterization of HIV infection in cisgender men and transgender women who have sex with men receiving injectable cabotegravir for HIV prevention: HPTN 083

INTRODUCTION

The HIV Prevention Trials Network (HPTN) 083 trial demonstrated that long-acting cabotegravir (CAB-LA) was more effective than tenofovir disoproxil fumarate/emtricitabine (TDF/FTC) for HIV prevention in cisgender men and transgender women who have sex with men. We characterized HIV infections that occurred in the blinded phase of HPTN 083.

METHODS

Retrospective testing included HIV testing, viral load testing, quantification of study drugs and HIV drug resistance testing.

RESULTS

Fifty-eight infections were evaluated, including 51 incident infections (12 CAB, 39 TDF/FTC). In many cases (5 CAB, 37 TDF/FTC), infection was associated with low or unquantifiable study drug concentrations. In four cases, infection occurred with on-time CAB-LA injections and expected plasma CAB concentrations. CAB exposure was associated with prolonged viral suppression and delayed antibody expression. In some cases, delayed HIV diagnosis resulted in CAB provision to participants with undetected infection, delayed antiretroviral treatment (ART), and emergence of drug resistance; most of these infections would have been detected earlier with viral load testing.

CONCLUSIONS

Early detection of HIV infection and prompt ART initiation could improve clinical outcomes in persons who become infected despite CAB-LA prophylaxis. Further studies are needed to elucidate the correlates of HIV protection in persons receiving CAB-LA.

Sharing Objective Measures of Adherence to a Vaginal Microbicide Promotes Candor About Actual Use and Bolsters Motivation to Prevent HIV

Discrepancies between self-reported and actual adherence to biomedical HIV interventions is common and in clinical trials can compromise the integrity of findings. One solution is to monitor adherence biomarkers, but it is not well understood how to navigate biomarker feedback with participants. We surveyed 42 counselors and interviewed a subset of 22 to characterize their perspectives about communicating with participants about residual drug levels, an objective marker of adherence, within MTN-025/HOPE, a Phase 3b clinical trial of a vaginal ring to prevent HIV. When biomarkers indicated low drug levels that mismatched high adherence by self-report, counselors encountered barriers to acceptance and comprehension among participants. However, discrepancies between low self-report and higher drug levels generally stimulated candor. Women recollected times they had not used the product and disclosed problems that counselors thought might otherwise have remained forgotten or concealed. Navigating conversations toward HIV prevention was easier at mid-range drug levels and when women indicated motivation to prevent HIV. Ratings of residual drug level offered a somewhat objective measure of adherence and protection that counselors perceived as meaningful to participants and as a valuable catalyst for broaching conversation about HIV prevention. However, communication about drug levels required that counselors navigate emotional barriers, respond skillfully to questions about accuracy, and pivot conversations non-judgmentally away from numerical results and toward the priority of HIV prevention. Findings suggest a role for biomarker feedback in future clinical trials as well as other clinical contexts where biomarkers may be monitored, to motivate disclosure of actual adherence and movement toward HIV prevention.Clinical Trial Number NCT02858037.

The PEARL study: a prospective two-group pilot PrEP promotion intervention for cisgender female sex workers living in Baltimore, MD, U.S

HIV remains elevated among female sex workers (FSW) globally, with a number of structural (e.g., poverty, access to care) factors driving these persistently high rates. Pre-exposure prophylaxis (PrEP), a user-controlled prevention method, is a promising means of empowering vulnerable populations to protect themselves and enhance agency. Yet there is a dearth of PrEP research and interventions targeting cisgender women in the United States, and even fewer aimed to reach FSW. We developed and implemented a multifaceted PrEP pilot intervention, the Promoting Empowerment And Risk Reduction (PEARL) study, to meet this gap. This paper describes the development process and nature of a community-informed intervention for tenofovir/emticitrabine (TDF/FTC) pre-exposure prophylaxis engagement among street-based cisgender FSW in Baltimore, Maryland, U.S. In the course of the study's implementation, structural, programmatic, and medical barriers have already posed significant barriers to full engagement. PEARL implemented a number of strategies in an effort to counter barriers and facilitate increased success of PrEP uptake and maintenance. The study will provide critical insights into the nature of intervention components that could help FSW to initiate PrEP and reduce PrEP care cascade gaps.

Approaches to Objectively Measure Antiretroviral Medication Adherence and Drive Adherence Interventions

PURPOSE OF REVIEW

Traditional methods to assess antiretroviral adherence, such as self-report, pill counts, and pharmacy refill data, may be inaccurate in determining actual pill-taking to both antiretroviral therapy (ART) or pre-exposure prophylaxis (PrEP). HIV viral loads serve as surrogates of adherence on ART, but loss of virologic control may occur well after decreases in adherence and viral loads are not relevant to PrEP.

RECENT FINDINGS

Pharmacologic measures of adherence, electronic adherence monitors, and ingestible electronic pills all serve as more objective metrics of adherence, surpassing self-report in predicting outcomes. Pharmacologic metrics can identify either recent adherence or cumulative adherence. Recent dosing measures include antiretroviral levels in plasma or urine, as well as emtricitabine-triphosphate in dried blood spots (DBS) for those on tenofovir-emtricitabine-based therapy. A urine tenofovir test has recently been developed into a point-of-care test for bedside adherence monitoring. Cumulative adherence metrics assess adherence over weeks to months and include measurement of tenofovir-diphosphate in peripheral blood mononuclear cells or DBS, as well as ART levels in hair. Electronic adherence monitors and ingestible electronic pills can track pill bottle openings or medication ingestion, respectively. New and objective approaches in adherence monitoring can be used to detect nonadherence prior to loss of prevention efficacy or virologic control with PrEP or ART, respectively.

The PrEPARE Pretoria Project: protocol for a cluster-randomized factorial-design trial to prevent HIV with PrEP among adolescent girls and young women in Tshwane, South Africa

BACKGROUND

Despite increased prevention efforts, HIV remains the leading cause of death among adolescent girls and young women in South Africa. Although research indicates important determinants of HIV acquisition at the individual and interpersonal levels, structural-level stigma and discrimination continue to be critical barriers to reaching and retaining this key population for HIV prevention and sexual and reproductive health services. Innovative and multilevel interventions are needed that can address the intersectional structural and gender issues that young women face, including stigma, alcohol and drug use, gender-based violence, and other risk factors when seeking health services. Oral pre-exposure prophylaxis (PrEP) taken daily has been found to be an effective biomedical HIV prevention tool. Testing a comprehensive gender-focused biobehavioral HIV prevention intervention that is inclusive of social ecological determinants, such as stigma and discrimination reduction in clinics, is critical for reducing HIV among adolescent girls and young women.

METHODS

This project involves both a Community Collaborative Board and a Youth Advisory Board in helping to adapt the Young Women's Health CoOp intervention and the Health Policy Project (HPP) Stigma and Discrimination (S&D) reduction training curriculum to the setting and population. This study uses a two-by-two factorial design with stratified randomization of 12 clinics, each with distinct catchment areas. The Young Women's Health CoOp addresses substance use, sexual risk, violence prevention and sexual negotiation, condom demonstration, and problem solving with the following additions: knowledge of PrEP, the importance of PrEP adherence, and sexual and reproductive health. Adolescent girls and young women will be assessed with behavioral and biological measures at baseline, 3-, 6- and 9-month follow-up. The S&D reduction training is provided for all staff in the clinics randomized to this condition. Clinic staff will be surveyed at baseline, 4- and 8-month follow-up. We will recruit 900 AGYW from communities in the 12 clinic catchment areas.

DISCUSSION

The study findings, if efficacious across the outcomes, will be incorporated into the gender-focused HIV prevention intervention toolkit and disseminated to inform multilevel prevention approaches.

TRIAL REGISTRATION

ClinicalTrials.gov. Identifier: NCT04048551 (Recruiting). Registered: August 7, 2019 (Retrospectively registered).

Comparison of adherence measurement tools used in a pre-exposure prophylaxis demonstration study among female sex workers in Benin

BACKGROUND

Measuring adherence to PrEP (pre-exposure prophylaxis) remains challenging. Biological adherence measurements are reported to be more accurate than self-reports and pill counts but can be expensive and not suitable on a daily basis in resource-limited countries. Using data from a demonstration project on PrEP among female sex workers in Benin, we aimed to measure adherence to PrEP and compare self-report and pill count adherence to tenofovir (TFV) disoproxil fumarate (TDF) concentration in plasma to determine if these 2 measures are reliable and correlate well with biological adherence measurements.

METHODS

Plasma TFV concentrations were analyzed in samples collected at day 14 follow-up visit and months 6, 12, 18, and 24 (or at last visit when follow-up was shorter). Self-reported adherence was captured at day 14 follow-up visit and then quarterly by asking participants to report the number of missed pills within the last week. For pill count, medications were refilled monthly and participants were asked to bring in their medication bottles at each follow-up visit. Using generalized estimating equations adherence measured by self-report and pill count was compared to plasma drug concentrations.

RESULTS

Of 255 participants, 47.1% completed follow-up. Weighted optimal adherence combining data from all visits was 26.8% for TFV concentration, 56.0% by self-report and 18.9% by pill count. Adherence measured by both TFV concentrations and self-report decreased over time (P = .009 and P = .019, respectively), while the decreasing trend in adherence by pill count was not significant (P = .087). The decrease in adherence was greater using TFV concentrations than the other 2 adherence measures.

CONCLUSION

With high levels of misreporting of adherence using self-report and pill count, the objective biomedical assessment of adherence via laboratory testing is optimal and more accurately reflects PrEP uptake and persistence. Alternative inexpensive and accurate approaches to monitor PrEP adherence should be investigated.

The PrEP Care Continuum Among Cisgender Women Who Sell Sex and/or Use Drugs Globally: A Systematic Review

HIV prevalence among cisgender female sex workers (FSW) and/or women who use drugs (WWUD) is substantially higher compared to similarly aged women. Consistent with PRISMA guidelines, we conducted the first systematic review on the pre-exposure prophylaxis (PrEP) continuum among FSW and/or WWUD, searching PubMed, Embase, CINAHL, PsycInfo, and Sociological Abstracts. Eligibility criteria included: reporting a PrEP related result among FSW and/or WWUD aged 18 + ; peer-reviewed; and published in English between 2012 and 2018. Our search identified 1365 studies; 26 met eligibility requirements, across the following groups: FSW (n = 14), WWUD (n = 9) and FSW-WWUD (n = 3). Studies report on at least one PrEP outcome: awareness (n = 12), acceptability (n = 16), uptake (n = 4), and adherence (n = 8). Specific barriers span individual and structural levels and include challenges to daily adherence, cost, and stigma. Combining health services and long-acting PrEP formulas may facilitate better PrEP uptake and adherence. The limited number of studies indicates a need for more research.

Testing a Real-Time Tenofovir Urine Adherence Assay for Monitoring and Providing Feedback to Preexposure Prophylaxis in Kenya (PUMA): Protocol for a Pilot Randomized Controlled Trial

BACKGROUND

The worldwide expansion of preexposure prophylaxis (PrEP) with oral tenofovir-disoproxil-fumarate/emtricitabine will be critical to ending the HIV epidemic. However, maintaining daily adherence to PrEP can be difficult, and the accuracy of self-reported adherence is often limited by social desirability bias. Pharmacologic adherence monitoring (measuring drug levels in a biomatrix) has been critical to interpreting PrEP trials, but testing usually requires expensive equipment and skilled personnel. We have recently developed a point-of-care (POC) immunoassay to measure tenofovir in urine, allowing real-time adherence monitoring for the first time.

OBJECTIVE

The goal of this study is to examine a point-of-care adherence metric in PrEP to support and increase adherence via a randomized controlled trial.

METHODS

The paper describes the protocol for a pilot randomized controlled trial to test the acceptability, feasibility, and impact on long-term adherence of implementing a POC urine test to provide real-time adherence feedback among women on PrEP. Eligible women (n=100) will be HIV-negative, ≥18 years old, and recruited from a clinic in Kenya that provides PrEP. Participants will be randomized 1:1 to the intervention of providing real-time feedback via the assay versus standard of care adherence counseling. Acceptability by participants will be assessed by a quantitative survey, as well as by qualitative data collected via in-depth interviews (n=20) and focus group discussions (n=4 groups, 5-10 women each). Feasibility will be assessed by the proportion of women retained in the study, the mean number of missed visits, the proportion of planned urine assessments completed, and messages delivered, while in-depth interviews with providers (n=8) will explore the ease of administering the urine test. Tenofovir levels in hair will serve as long-term adherence metrics. A linear mixed-effects model will estimate the effect of the intervention versus standard of care on logarithmically transformed levels of tenofovir in hair.

RESULTS

This study has been funded by the National Institute of Health, approved by the Kenya Medical Research Institute Institutional Review Board, and will commence in June 2020.

CONCLUSIONS

A novel urine assay to measure and deliver information on adherence to PrEP in real-time will be tested for the first time in this trial planned among women on PrEP in Kenya. Study findings will inform a larger-scale trial assessing the impact of real-time adherence monitoring/feedback on HIV prevention. Improving adherence to PrEP will have long-term implications for efforts to end the HIV epidemic worldwide.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03935464; https://clinicaltrials.gov/ct2/show/NCT03935464.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

PRR1-10.2196/15029.

A Subcutaneous Implant of Tenofovir Alafenamide Fumarate Causes Local Inflammation and Tissue Necrosis in Rabbits and Macaques

We describe the in vitro and in vivo evaluation of a subcutaneous reservoir implant delivering tenofovir alafenamide hemifumarate (TAF) for the prevention of HIV infection. These long-acting reservoir implants were able to deliver antiretroviral drug for over 90 days in vitro and in vivo. We evaluated the implants for implantation site histopathology and pharmacokinetics in plasma and tissues for up to 12 weeks in New Zealand White rabbit and rhesus macaque models.

We describe the in vitro and in vivo evaluation of a subcutaneous reservoir implant delivering tenofovir alafenamide hemifumarate (TAF) for the prevention of HIV infection. These long-acting reservoir implants were able to deliver antiretroviral drug for over 90 days in vitro and in vivo. We evaluated the implants for implantation site histopathology and pharmacokinetics in plasma and tissues for up to 12 weeks in New Zealand White rabbit and rhesus macaque models. A dose-ranging study in rabbits demonstrated dose-dependent pharmacokinetics and local inflammation up to severe necrosis around the active implants. The matched placebos showed normal wound healing and fibrous tissue encapsulation of the implant. We designed a second implant with a lower release rate and flux of TAF and achieved a median cellular level of tenofovir diphosphate of 42 fmol per 10⁶ rhesus macaque peripheral blood mononuclear cells at a TAF dose of 10 μg/kg/day. This dose and flux of TAF also resulted in adverse local inflammation and necrosis near the implant in rhesus macaques. The level of inflammation in the primates was markedly lower in the placebo group than in the active-implant group. The histological inflammatory response to the TAF implant at 4 and 12 weeks in primates was graded as a severe reaction. Thus, while we were able to achieve a sustained target dose, we observed an unacceptable inflammatory response locally at the implant tissue interface.

Development and validation of the first point-of-care assay to objectively monitor adherence to HIV treatment and prevention in real-time in routine settings

OBJECTIVE

HIV prevention and treatment studies demonstrate that pharmacologic adherence metrics are more accurate than self-report. Currently available metrics use liquid-chromatography/tandem-mass-spectrometry (LC-MS/MS), which is expensive and laboratory-based. We developed a specific and sensitive antibody against tenofovir, the backbone of treatment and prevention, but conversion to a lateral flow assay (LFA) - analogous to a urine pregnancy test - is required for point-of-care testing. We describe the development of the first LFA to measure antiretroviral adherence in real-time.

METHODS

Previous work in a directly observed therapy study of providing tenofovir disoproxil fumarate (TDF) to HIV-noninfected volunteers at various simulated adherence patterns defined the appropriate cut-off for the LFA (1500 ng tenofovir/ml urine). We developed the LFA using a sample pad for urine; a conjugate pad coated with TFV-specific antibodies conjugated to colloidal gold nanoparticles; a nitrocellulose membrane striped with tenofovir-antigen (test line) and a control line; with an absorbent pad to draw urine across the reaction membrane.

RESULTS

We tested 300 urine samples collected from the directly observed therapy study by this LFA and the gold-standard method of LC-MS/MS. The LFA demonstrated 97% specificity (95% CI 93-99%) and 99% sensitivity (94-100%) compared with LC-MS/MS. The LFA accurately classified 98% of patients who took a dose within 24 h as adherent.

CONCLUSION

We describe the development and validation of the first point-of-care assay to measure short-term adherence to HIV prevention and treatment in routine settings. The assay is low-cost, easy-to-perform and measures the breakdown product (tenofovir) of both TDF and tenofovir alafenamide (TAF). This assay has the potential to improve HIV and PrEP outcomes worldwide by triggering differentiated service delivery with further study merited.

Perspectives from Young South African and Zimbabwean Women on Attributes of Four (Placebo) Vaginal Microbicide Delivery Forms

Introduction

Incorporating end-user input into the design of new vaginal microbicides for women is key to optimizing their uptake, consistent use, and, ultimately, success in combatting the heterosexual HIV epidemic.

Methods

The Quatro Study assessed four placebo forms of vaginally inserted HIV-microbicides among young microbicide-naïve African women: on-demand film, insert and gel, and monthly ring. Participants randomly used each product for 1 month and provided product satisfaction ratings (1–5 scale), and opinions on product attributes and potential alternative designs. Qualitative data were collected through focus group discussions at study exit. Multivariable associations between attribute opinions and overall product rating were examined using Poisson regression models with robust standard errors to assess the attributes most influential to satisfaction.

Results

Overall opinions of products and their individual attributes were generally positive; all products were rated either 4 or a 5 by ≥ 50% of participants. Attributes related to ease of use and interference with normal activities were the most salient predictors of satisfaction. Preferences for duration of use tended toward relatively shorter use periods for the ring (i.e., 1–3 months vs. 12 months) and for coitally independent dosing for the on-demand products.

Conclusions

How well a product fit in with participants’ lifestyles was important to their overall satisfaction. For on-demand products, greater flexibility around timing of use was desired, to avoid coital dependency of the dosing.

Electronic supplementary material

The online version of this article (10.1007/s10461-019-02576-8) contains supplementary material, which is available to authorized users.

Young Women's Stated Preferences for Biomedical HIV Prevention: Results of a Discrete Choice Experiment in Kenya and South Africa

Supplemental Digital Content is Available in the Text.

Background:

Integrating end-user perspectives into the design of new biomedical HIV prevention products is recognized as vital to informing the product development pipeline.

Setting:

Kisumu, Kenya; and Soshanguve, South Africa.

Methods:

We conducted a discrete choice experiment survey with 536 women aged 18–30 years to assess preferences for hypothetical HIV prevention products characterized by the attributes of efficacy, pregnancy prevention, delivery form, dosing frequency, and side effects. Participants included product-experienced women from Tablet, Ring, Injection as Options TRIO, a cross-over clinical study evaluating 3 placebo delivery forms (oral tablets, vaginal rings, and injections), and a product-naive sample recruited from the same communities. Analyses used random parameters logit and latent class models.

Results:

HIV prevention efficacy was a strong determinant of stated choice overall; however, in South Africa, delivery form was just as important, with an injection every 2–3 months most preferred and a daily oral tablet least preferred. In Kenya, product-experienced women preferred monthly injections and least preferred a monthly ring. Respondents indicated a preference for multipurpose prevention technologies that combine HIV and pregnancy protection. Latent class analyses confirmed these findings and delineated heterogeneity in preferences across subgroups defined by age, past experience with the delivery forms, and education.

Conclusions:

Despite an overall preference for products with high efficacy, we identified attributes salient to future uptake and use of HIV prevention products. Preferences for injectable products underscored interest in this pre-exposure prophylaxis delivery form. Likewise, the multipurpose prevention technology feature was valued in both Kenya and South Africa and most influenced interest in vaginal rings.

Vulnerable Periods: Characterizing Patterns of Sexual Risk and Substance Use During Lapses in Adherence to HIV Pre-exposure Prophylaxis Among Men Who Have Sex With Men

BACKGROUND

Pre-exposure prophylaxis (PrEP) is highly efficacious, but some groups of men who have sex with men may have difficulty adhering to daily dosing. Prevention-effective adherence suggests that PrEP's efficacy depends on adherence at the time of HIV exposure; yet, few studies have examined how exposures (ie, high-risk sex) overlap with periods of consecutive missed PrEP doses. Substance use may also play a role in these vulnerable periods.

METHODS

We used digital pill bottles to monitor the daily adherence of 40 PrEP-experienced patients recruited from an outpatient clinic in the Northeastern US over a six-month period. Participants also completed detailed online diaries every 2 weeks during this time that surveyed their sexual behavior and substance use each day.

RESULTS

Daily adherence was high overall (M = 83.9%, SD = 18.0%), but 53% (N = 21) had a lapse of > 3 consecutive daily PrEP doses over 6 months. Participants' rate of engaging in high-risk condomless anal sex (CAS) did not differ across lapse days versus continuously adherent days. Alcohol use was not associated with engaging in CAS during a PrEP lapse. However, participants reported engaging in CAS significantly more often during a PrEP adherence lapse on days when they also used stimulant drugs.

CONCLUSIONS

Men who have sex with men may have periodic difficulty adhering to PrEP at the specific times when they are at risk. Stimulant drug use could play an important role in increasing HIV risk specifically during adherence lapses.

PrEP Discontinuation and Prevention-Effective Adherence: Experiences of PrEP Users in Ugandan HIV Serodiscordant Couples

BACKGROUND

Optimal adherence to oral pre-exposure prophylaxis (PrEP) for HIV prevention involves aligning consistent PrEP use with periods of risk to achieve prevention-effective adherence. Prevention-effective adherence is predicated on individuals discontinuing PrEP during periods without expected risk. For stable, serodiscordant couples, antiretroviral therapy (ART) adherence by the HIV-positive partner markedly decreases HIV transmission risk, potentially obviating the need for continued PrEP use; yet little is known about actual lived experiences of discontinuing PrEP.

METHODS

In-depth qualitative interviews were conducted with HIV-uninfected PrEP users in serodiscordant couples taking part in the Partners Demonstration Project at IDI-Kasangati, Kampala, Uganda. Open-ended interviews elicited information on the partnered relationship; understandings of PrEP; prevention strategies; and experiences of PrEP discontinuation. An inductive, thematic, content-analytic approach was used to analyze study data.

RESULTS

Uninfected partners experienced PrEP as a valued resource for preventing HIV acquisition. Despite ongoing ART use by HIV-positive partners for a period of time consistent with viral suppression, discontinuation of PrEP was experienced as a loss of protection and a corresponding increase in risk of HIV acquisition. Uninfected partners responded with strategies aimed at offsetting this subjective sense of increased risk, specifically: (1) changing sexual practices; (2) prioritizing fidelity in the relationship; (3) increasing reliance on condoms; and (4) seeking evidence of partners' ART adherence.

CONCLUSIONS

These experiences highlight the challenges PrEP users in serodiscordant couples face in discontinuing PrEP for prevention-effective adherence. Flexible interventions that support individuals during this transition may increase comfort with discontinuing PrEP when alternative prevention strategies provide protection, such as a partner's consistent adherence to ART.

Comparing Self-Report Pre-Exposure Prophylaxis Adherence Questions to Pharmacologic Measures of Recent and Cumulative Pre-Exposure Prophylaxis Exposure

As pre-exposure prophylaxis (PrEP) effectiveness is strongly linked to adherence, we sought to determine if certain self-report measures could be used to inform objective PrEP adherence. We studied participants from the TAPIR study (a multicenter randomized study of daily text messages to support adherence to PrEP In At-Risk), a 48-week randomized controlled trial of HIV-uninfected men who have sex with men (MSM) randomized to receive text message to support adherence versus standard of care. Self-reported medication adherence was assessed using several validated measures modified for PrEP. Objective PrEP adherence was determined through dried blood spot (DBS) measurement of intracellular tenofovir diphosphate (TFV-DP) and emtricitabine triphosphate (FTC-TP). A summary of adherence was estimated using responses to the seven adherence items at weeks 12 and 48 using confirmatory factor analysis. Correlations between self-report questions and drug concentrations were estimated with Pearson's correlations for continuous outcomes and point-biserial correlations for dichotomous outcomes. Receiver operating characteristic (ROC) analyses were conducted to assess the performance of self-report measures in predicting protective or perfect TFV-DP concentrations. Of the 369 participants who completed week 12 or 48 visits, the mean age was 35 (standard deviation 9 years), with 79% White, 12% Black, and 29% Hispanic. Correlations between self-report measures of adherence (both individual items and the adherence factor) and quantifiable FTC-TP and continuous TFV-DP concentrations showed that all self-report measures were significantly associated with these objective measures. Compared to a summary measure of self-reported adherence, the 4-week percent taken question medication recall was the only self-report item similarly or more strongly associated with recent adherence and long-term protective and perfect adherence at weeks 12 and 48. ROC analysis also showed that 4-week percent taken question had a reasonable AUC (0.798 at week 12 and 0.758 at week 48) in predicting protective TFV-DP concentrations. All single-item self-report questions assessing PrEP adherence were significantly associated with biomarker quantification, with the 4-week percent taken question performing best. Therefore, in the absence of drug concentration measurements, a 4-week self-report percent taken question may be a good single-item measure of PrEP adherence.

Measuring Adherence to Antiretroviral Therapy via Hair Concentrations in India

BACKGROUND

Objective adherence measures are of increasing interest in antiretroviral treatment (ART) monitoring. Hair ART levels predict virologic suppression, and hair is easy to collect and store. No previous study has examined hair levels in an India-based cohort or laboratory.

METHODS

Small hair samples were collected from HIV-positive participants on either efavirenz (EFV)-based or nevirapine (NVP)-based ART in a South India-based study. Hair samples were split and analyzed for EFV or NVP in the University of California, San Francisco -based Hair Analytical Laboratory and the analytic laboratory of the Division of Nutrition at St. John's Research Institute, Bangalore, India, using liquid chromatography/tandem mass spectrometry. Agreement (using Bland-Altman methods) and rank correlation between the 2 laboratories' hair levels were calculated. Rank correlation between self-reported adherence (SRA) over the previous month using a visual analog scale and hair ART levels was calculated.

RESULTS

Among 75 participants (38 on NVP; 37 on EFV), the correlation between NVP levels generated by the 2 laboratories was 0.66 (P < 0.0001) and between EFV levels was 0.87 (P < 0.0001). Measurements from St. John's Research Institute were usually within 20% of those from the University of California, San Francisco Hair Analytical Laboratory. SRA was essentially uncorrelated with hair antiretroviral levels for either drug (all correlations < 0.04). Hair levels showed variability in adherence although SRA was >85% in all participants.

CONCLUSIONS

Hair ART levels measured by both an India-based laboratory and the standard U.S.-based laboratory showed generally high agreement and correlation, demonstrating local capacity. As in many other cohorts, hair ART levels and SRA were not well-correlated, likely indicating limitations in self-report and the need for objective adherence monitoring in resource-limited settings.

Predictors of Daily Adherence to HIV Pre-exposure Prophylaxis in Gay/Bisexual Men in the PRELUDE Demonstration Project

Adequate adherence to pre-exposure prophylaxis (PrEP) is critical to prevent HIV infection, but accurately measuring adherence remains challenging. We compared two biological [blood drug concentrations in plasma and peripheral blood mononuclear cells (PBMC)] and two self-reported measures (facilitated recall to clinicians and self-report in online surveys) and identified predictors of daily PrEP adherence among gay and bisexual men (GBM) in their first 12 months on PRELUDE, an open-label, single-arm PrEP demonstration project in New South Wales, Australia. 327 participants were enrolled; 263 GBM attended their 12-month follow-up visit (81% retention). Overall, 91% of blood samples had plasma drug concentrations indicative of taking 7 pills/week, and 99% had protective drug concentrations (≥ 4 pills/week). Facilitated recall to clinicians identified 99% of participants with protective adherence as measured by PBMC drug concentrations. Daily adherence measured by facilitated recall was associated with behavioural practices including group sex (aOR 1.33, 95% CI 1.15-1.53, p < 0.001). Retained participants maintained high adherence to daily PrEP over 12 months, confirmed by four different measures. Facilitated recall to clinicians is a suitable measure for assessing PrEP adherence in populations engaged in care where there is established trust and rapport with patients. Trial registration: ClinicalTrials.gov NCT02206555.

Brief Report: Validation of a Urine Tenofovir Immunoassay for Adherence Monitoring to PrEP and ART and Establishing the Cutoff for a Point-of-Care Test

BACKGROUND

Current pharmacologic adherence monitoring for antiretrovirals involves expensive, labor-intensive liquid chromatography/tandem mass spectrometry (LC-MS/MS)-based methods. Antibody-based assays can monitor and support adherence in real time. We developed a tenofovir (TFV)-based immunoassay and further validated it in a directly observed therapy (DOT) study.

DESIGN

Pharmacologic DOT study of TFV disoproxil fumarate (TDF)/emtricitabine (FTC) administered to HIV-noninfected volunteers.

METHODS

The TARGET study provided directly observed TDF 300 mg/FTC 200 mg 7 (high adherence), 4 (moderate), and 2 doses/week (low) to 30 volunteers (10/group) in Thailand, collecting a total of 637 urine samples over 6 weeks of administration and during washout. ELISA measured urine TFV levels by the immunoassay and LC-MS/MS-based concentrations served as the gold standard. A mixed-effects regression model evaluated cutoffs for a point-of-care assay. Performance characteristics of the immunoassay were compared with LC-MS/MS at a chosen cutoff.

RESULTS

Median TFV levels were 12,000 ng/mL by the immunoassay 1 day after dosing; 5000 ng/mL 2 days after dosing; 1500 ng/mL 3 days after dosing; and below the lower limit of quantification thereafter (≥4 days). An immunoassay cutoff of 1500 ng/mL accurately classified 98% of patients who took a dose 24 hours ago as adherent. The specificity and sensitivity of the immunoassay compared with LC-MS/MS at the 1500 ng/mL cutoff were 99% and 94%; the correlation between TFV levels by the 2 assays was high (0.92, P < 0.00001).

CONCLUSIONS

We have developed a novel TFV immunoassay that is highly specific, sensitive, and correlates strongly with LC-MS/MS measurements in a large DOT study. Adherence benchmarks from this DOT study will guide the development of a low-cost rapid point-of-care test for pre-exposure prophylaxis and antiretroviral treatment adherence monitoring and interventions.

Pharmaceutical Vehicles for Vaginal and Rectal Administration of Anti-HIV Microbicide Nanosystems

Prevention strategies play a key role in the fight against HIV/AIDS. Vaginal and rectal microbicides hold great promise in tackling sexual transmission of HIV-1, but effective and safe products are yet to be approved and made available to those in need. While most efforts have been placed in finding and testing suitable active drug candidates to be used in microbicide development, the last decade also saw considerable advances in the design of adequate carrier systems and formulations that could lead to products presenting enhanced performance in protecting from infection. One strategy demonstrating great potential encompasses the use of nanosystems, either with intrinsic antiviral activity or acting as carriers for promising microbicide drug candidates. Polymeric nanoparticles, in particular, have been shown to be able to enhance mucosal distribution and retention of promising antiretroviral compounds. One important aspect in the development of nanotechnology-based microbicides relates to the design of pharmaceutical vehicles that allow not only convenient vaginal and/or rectal administration, but also preserve or even enhance the performance of nanosystems. In this manuscript, we revise relevant work concerning the selection of vaginal/rectal dosage forms and vehicle formulation development for the administration of microbicide nanosystems. We also pinpoint major gaps in the field and provide pertinent hints for future work.

Perspectives of US women participating in a candidate PrEP study: adherence, acceptability and future use intentions

INTRODUCTION

Limited data exist on acceptability of candidate pre-exposure prophylaxis (PrEP) regimens among US women. We evaluated PrEP experiences, attitudes and future use intentions among sexually active women who completed the US-based HIV Prevention Trials Network 069/AIDS Clinical Trials Group 5305 study.

METHODS

Women participated in the study between March 2013 and November 2015. We analysed computer-assisted self-interview (CASI) surveys among 130 women and conducted in-depth interviews among a subset of 26 women from three sites. Interviews were conducted in mid/late-2015.

RESULTS

Most women (57%) reported very good/excellent PrEP adherence on CASI, although 21% acknowledged over-reporting adherence at least some of the time. Commitment to preventing HIV infection, a sense of ownership of the study, and keeping pills stored in a visible location facilitated adherence. Adherence barriers included "simply forgetting" and being away from home. Most women interviewed did not intend to use PrEP in the future because of lack of perceived need due to their own (as opposed to their partners') low-risk behaviour and concerns about affordability - but not because of side effects or other characteristics of the regimens.

DISCUSSION

Improving HIV prevention options for US women will require access to affordable PrEP as well as expanding women's understanding of relationship- and community-level factors that increase their risk of acquiring HIV.

Vaginal Ring Use in a Phase 3 Microbicide Trial: A Comparison of Objective Measures and Self-reports of Non-adherence in ASPIRE

This analysis compares self-reports of product use with objective measures of non-adherence-quarterly plasma dapivirine levels and monthly residual dapivirine (DPV) levels in used rings-in MTN-020/ASPIRE, a phase 3 trial of a monthly DPV vaginal ring among women aged 18-45 years in Malawi, South Africa, Uganda and Zimbabwe. For participants on active product (N = 1211) we assessed self-reported monthly non-adherence, as measured by (1) whether the ring was ever out, and out for ≥ 12 h in the previous month and, (2) by a self-rating scale assessing ability to keep the vaginal ring inserted, and compared the self-reports to two biomarkers of non-use separately and as a composite measure. For this analysis, a plasma DPV value ≤ 95 pg/ml and residual ring ≥ 23.5 mg were used to classify non-adherence (i.e. the ring never being in the vagina the previous month). Compared to self-reports, non-adherence was found to be substantially higher for the composite measure as well as its two components, an indication that ring removal was likely underreported in the trial. The discrepancy between the self-report measure of ring outage and the composite indicator was greater for those aged 18-21 than for those older, evidence that younger women are more likely to underreport non-adherence. Despite underreporting of non-adherence, self-reports of the ring never being out were significant in predicting the composite objective measure. Furthermore, the association between the self-rating scale and the objective measure was in the expected direction and significant, although 11% of those 18-21 and 7% of those 22+ who rated their ability to keep the ring inserted as good, very good or excellent in the 4 weeks prior to exit were considered non-adherent according to the objective measure. This analysis indicates that while self-reports are significantly associated with objective measures of adherence in the ASPIRE trial, they were inflated-more so by those younger-and therefore may have limited utility identifying those who have challenges using products as directed. ClinicalTrials.gov number NCT01617096.

Fecal Coliform Bacterial Detection to Assess Enema Adherence in HIV Prevention Clinical Studies

Evaluating the efficacy of any HIV prevention strategy is dependent on ensuring and objectively monitoring adherence to the intervention. Medicated rectal enemas are a potential method for providing topical, episodic HIV prophylaxis during receptive anal intercourse. Assessing adherence to recommended enema dosing regimens is essential in evaluating the utility of this strategy. We utilized fecal coliform bacteria on used enema tips as a marker for enema use. Enema tip coliforms were tested by repurposing a microtiter plate-based water quality test designed to detect fecal contamination of water. Coliform detection occurred with 100% sensitivity and specificity when tips were assayed on day of use. The assay performed well post-7 day sample storage at room temperature, yielding a sensitivity of 80% and specificity of 93%. All (n = 64) samples collected in a subset of the DREAM-01 rectal microbicide enema clinical trial tested positive, even when tips were evaluated > 7 days post-reported use. The coliform-based enema tip assay allows monitoring of adherence in interventions involving rectal enemas in a sensitive, specific and inexpensive manner. The test performs well in clinical trial settings.

Effects of gel volume on pharmacokinetics for vaginal and rectal applications of combination DuoGel-IQB4012, a dual chamber-dual drug HIV microbicide gel, in pigtailed macaques

This study evaluated effects of differing gel volumes on pharmacokinetics (PK). IQB4012, a gel containing the non-nucleoside reverse transcriptase inhibitor IQP-0528 and tenofovir (TFV), was applied to the pigtailed macaque vagina and rectum. Vaginal gel volumes (1% loading of both drugs) were 0.5 or 1.5 ml; following wash-out, 1 or 4 ml of gel were then applied rectally. Blood, vaginal, and rectal fluids were collected at 0, 2, 4, and 24 h. Vaginal and rectal tissue biopsies were collected at 4 and 24 h. There were no statistically significant differences in concentrations for either drug between gel volumes within compartments at matched time points. After vaginal gel application, median IQP-0528 concentrations were ~ 10⁴-10⁵ ng/g, 10⁵-10⁶ ng/ml, and 10³-10⁵ ng/ml in vaginal tissues, vaginal fluids, and rectal fluids, respectively (over 24 h). Median vaginal TFV concentrations were 1-2 logs lower than IQP-0528 levels at matched time points. After rectal gel application, median IQP-0528 and TFV concentrations in rectal fluids were ~ 10³-10⁵ ng/ml and ~ 10²-10³ ng/ml, respectively. Concentrations of both drugs sampled in rectal tissues were low (~ 10¹-10³ ng/g). For 1 ml gel, half of sampled rectal tissues had undetectable concentrations of either drug, and over half of sampled rectal fluids had undetectable TFV concentrations. These results indicate differences in drug delivery between the vaginal and rectal compartments, and that smaller vaginal gel volumes may not significantly compromise microbicide PK and prophylactic potential. However, effects of rectal gel volume on PK for both drugs were less definitive.

Threefold Increase in PrEP Uptake Over Time with High Adherence Among Young Men Who Have Sex With Men in Chicago

The goal of this work is to better understand utilization and uptake of pre-exposure prophylaxis (PrEP) among young men who have sex with men (YMSM) and transgender women (TGW). We assessed trends and correlates of PrEP use and adherence across three time points of longitudinal data collection among 885 YMSM and TGW (aged 16-29) from the RADAR cohort in Chicago, 2015-2017. Past 6-month PrEP use increased across three visits: from 6.6 to 17.5%. In multivariable models, past 6-month PrEP use was significantly associated with participation in condomless sex, having more sexual partners, and older age. At least three-quarters of current PrEP users reported being ≥ 90% adherent to PrEP medication across all visits. Past 6-month PrEP use increased over time with those who participated in high-risk HIV behaviors also those most likely to have taken PrEP. As PrEP uptake continues to rise, more research will be needed to understand predictors of PrEP usage, as well as patterns of sexual behavior change following uptake.

Development and Validation of an Immunoassay for Tenofovir in Urine as a Real-Time Metric of Antiretroviral Adherence

BACKGROUND

Pharmacologic adherence measures were critical to the interpretation of the tenofovir (TFV)-disoproxil-fumarate/emtricitabine (TDF/FTC) PrEP trials. These measures are being incorporated into PrEP demonstration projects, but currently-available metrics in plasma, cells, hair or urine involve expensive and time-intensive mass-spectrometry (MS)-based methods. No point-of-care method to assess PrEP adherence in real-time has yet been implemented. Antibody-based tests allow for low-cost, easy-to-perform, point-of-care drug detection. In this study, we developed an antibody-based TFV immunoassay and evaluated its test characteristics among individuals taking TDF/FTC.

METHODS

We synthesized possible immunogens based on TFV's molecular structure, injected rabbits with the conjugated derivatives, and bled them monthly for subsequent ELISA-testing for TFV-specific antibodies. We purified an antibody with specific TFV binding and created dose-response curves for ELISA-quantification. We then quantified TFV in urine from human participants not taking TDF/FTC and from individuals taking daily TDF/FTC 300 mg/200 mg for 7 days with a 7-day washout period using ELISA with this TFV-specific antibody. ELISA results were compared with the gold-standard test for TFV detection/quantification using liquid-chromatography-tandem-MS (LC-MS/MS).

FINDINGS

None of the urine samples from 115 participants not taking TDF/FTC showed ELISA- reactivity, indicating 100% specificity (95% CI 97-100%) of the immunoassay. Among participants taking TDF/FTC, 67 of 70 samples positive by LC-MS/MS were positive by the ELISA-immunoassay for an estimated diagnostic sensitivity of 96% (95% CI 88-99%). The precision of the assay was high (coefficient of variationb15%). The rank correlation between ELISA and LC-MS/MS values in the 70 quantitative urine TFV levels positive by LC-MS/MS across a wide range of concentrations among participants on TDF/FTC was high (r = 0.96).

INTERPRETATION

Our antibody-based immunoassay for measuring TFV in urine performed well compared to the gold-standard of LC-MS/MS among individuals taking TDF/FTC. A sensitive and specific immunoassay paves the way for real-time monitoring/feedback on recent adherence to TFV-based regimens, which should optimize interpretation and outcomes during PrEP and ART roll-out.

Optimizing adherence in HIV prevention product trials: Development and psychometric evaluation of simple tools for screening and adherence counseling

Background

Low adherence in recent HIV prevention clinical trials highlights the need to better understand, measure, and support product use within clinical trials. Conventional self-reported adherence instruments within HIV prevention trials, often relying on single-item questions, have proven ineffective. While objective adherence measures are desirable, none currently exist that apply to both active and placebo arms. Scales are composed of multiple items in the form of questions or statements that, when combined, measure a more complex construct that may not be directly observable. When psychometrically validated, such measures may better assess the multiple factors contributing to adherence/non-adherence. This study aimed to develop and psychometrically evaluate tools to screen and monitor trial participants’ adherence to HIV prevention products within the context of clinical trial research.

Methods and findings

Based on an extensive literature review and conceptual framework, we identified and refined 86 items assessing potential predictors of adherence and 48 items assessing adherence experience. A structured survey, including adherence items and other variables, was administered to former ASPIRE and Ring Study participants and similar non-trial participants (n = 709). We conducted exploratory factor analyses (EFA) to identify a reduced set of constructs and items that could be used at screening to predict potential adherence, and at follow-up to monitor and intervene on adherence. We examined associations with other variables to assess content and construct validity. The EFA of screener items resulted in a 6-factor solution with acceptable to very good internal reliability (α: .62-.84). Similar to our conceptual framework, factors represent trial-related commitment (Distrust of Research and Commitment to Research); alignment with trial requirements (Visit Adherence and Trial Incompatibility); Belief in Trial Benefits and Partner Disclosure. The EFA on monitoring items resulted in 4 Product-specific factors that represent Vaginal Ring Doubts, Vaginal Ring Benefits, Ring Removal, and Side Effects with good to very good internal reliability (α = .71-.82). Evidence of content and construct validity was found; relationship to social desirability bias was examined.

Conclusions

These scales are easy and inexpensive to administer, available in several languages, and are applicable regardless of randomization. Once validated prospectively, they could (1) screen for propensity to adhere, (2) target adherence support/counselling, and (3) complement biomarker measures in determining true efficacy of the experimental product.

How Presentation of Drug Detection Results Changed Reports of Product Adherence in South Africa, Uganda and Zimbabwe

Accurate estimates of study product use are critical to understanding and addressing adherence challenges in HIV prevention trials. The VOICE trial exposed a significant gap between self-reported adherence and drug detection. The VOICE-D qualitative study was designed to better understand non-adherence during VOICE, and was conducted in 2 stages: before (stage 1) and after (stage 2) drug detection results were provided to participants. Transcripts from 44 women who participated in both stages were analysed to understand the effect of presenting drug detection data on narratives of product use. Thirty-six women reported high adherence in stage 1, yet admitted non-use in stage 2, three reported high adherence in both stages (contrary to their drug detection results) and five had consistent responses across both stages and drug results. Presenting objective measures of use may facilitate more accurate product use reporting and should be evaluated in future prevention trials.

Residual hormone levels in used contraceptive rings as a measurement of adherence to vaginal ring use

OBJECTIVE

This study sought to measure residual contraceptive hormone levels in vaginal rings as an adherence marker for monitoring product use in clinical trials.

STUDY DESIGN

Residual etonogestrel and ethinyl estradiol levels from used NuvaRings® of 26 self-reported adherent women enrolled in a clinical trial of vaginal ring acceptability were compared to those from 16 women who used NuvaRing® as their contraceptive choice.

RESULTS

Twenty-one (81%) clinical trial rings had contraceptive hormone levels within the range of those used as a contraceptive choice. Five returned rings had unused or discordant levels of residual contraceptive hormones.

CONCLUSION

Residual vaginal ring drug levels could help assess adherence in clinical trials.

Misreporting of Product Adherence in the MTN-003/VOICE Trial for HIV Prevention in Africa: Participants' Explanations for Dishonesty

Consistent over-reporting of product use limits researchers' ability to accurately measure adherence and estimate product efficacy in HIV prevention trials. While lying is a universal characteristic of the human condition, growing evidence of a stark discrepancy between self-reported product use and biologic or pharmacokinetic evidence demands examination of the reasons research participants frequently misrepresent product use in order to mitigate this challenge in future research. This study (VOICE-D) was an ancillary post-trial study of the vaginal and oral interventions to control the epidemic (VOICE) phase IIb trial (MTN 003). It was conducted in three African countries to elicit candid accounts from former VOICE trial participants about why actual product use was lower than reported. In total 171 participants were enrolled between December 2012 and March 2014 in South Africa (n = 47), Uganda (n = 59) and Zimbabwe (n = 65). Data suggested that participants understood the importance of daily product use and honest reporting, yet acknowledged that research participants typically lie. Participants cited multiple reasons for misreporting adherence, including human nature, self-presentation with study staff, fear of repercussions (study termination resulting in loss of benefits and experience of HIV-related stigma), a permissive environment in which it was easy to get away with misreporting, and avoiding inconvenient additional counseling. Some participants also reported mistrust of the staff and reciprocal dishonesty about the study products. Many suggested real-time blood-monitoring during trials would encourage greater fidelity to product use and honesty in reporting. Participants at all sites understood the importance of daily product use and honesty, while also acknowledging widespread misreporting of product use. Narratives of dishonesty may suggest a wider social context of hiding products from partners and distrust about research, influenced by rumors circulating in clinic waiting-rooms and surrounding communities. Prevailing power hierarchies between staff and participants may exacerbate misreporting. Participants recognized and suggested that objective, real-time feedback is needed to encourage honest reporting.