Cabotegravir for HIV Prevention in Cisgender Men and Transgender Women

BACKGROUND

Safe and effective long-acting injectable agents for preexposure prophylaxis (PrEP) for human immunodeficiency virus (HIV) infection are needed to increase the options for preventing HIV infection.

METHODS

We conducted a randomized, double-blind, double-dummy, noninferiority trial to compare long-acting injectable cabotegravir (CAB-LA, an integrase strand-transfer inhibitor [INSTI]) at a dose of 600 mg, given intramuscularly every 8 weeks, with daily oral tenofovir disoproxil fumarate-emtricitabine (TDF-FTC) for the prevention of HIV infection in at-risk cisgender men who have sex with men (MSM) and in at-risk transgender women who have sex with men. Participants were randomly assigned (1:1) to receive one of the two regimens and were followed for 153 weeks. HIV testing and safety evaluations were performed. The primary end point was incident HIV infection.

RESULTS

The intention-to-treat population included 4566 participants who underwent randomization; 570 (12.5%) identified as transgender women, and the median age was 26 years (interquartile range, 22 to 32). The trial was stopped early for efficacy on review of the results of the first preplanned interim end-point analysis. Among 1698 participants from the United States, 845 (49.8%) identified as Black. Incident HIV infection occurred in 52 participants: 13 in the cabotegravir group (incidence, 0.41 per 100 person-years) and 39 in the TDF-FTC group (incidence, 1.22 per 100 person-years) (hazard ratio, 0.34; 95% confidence interval, 0.18 to 0.62). The effect was consistent across prespecified subgroups. Injection-site reactions were reported in 81.4% of the participants in the cabotegravir group and in 31.3% of those in the TDF-FTC group. In the participants in whom HIV infection was diagnosed after exposure to CAB-LA, INSTI resistance and delays in the detection of HIV infection were noted. No safety concerns were identified.

CONCLUSIONS

CAB-LA was superior to daily oral TDF-FTC in preventing HIV infection among MSM and transgender women. Strategies are needed to prevent INSTI resistance in cases of CAB-LA PrEP failure. (Funded by the National Institute of Allergy and Infectious Diseases and others; HPTN 083 ClinicalTrials.gov number, NCT02720094.).

Optimizing Pre-Exposure Antiretroviral Prophylaxis Adherence in Men Who Have Sex with Men: Results of a Pilot Randomized Controlled Trial of "Life-Steps for PrEP"

Antiretroviral pre-exposure prophylaxis (PrEP) has been demonstrated to decrease HIV acquisition in multiple efficacy trials, but medication adherence is critical, and was suboptimal in several studies. Fifty HIV-uninfected at risk men who have sex with men (MSM) were randomized to a cognitive behavioral intervention condition or a time and session-matched comparison counseling intervention. The experimental intervention entailed four nurse-delivered initial and two booster sessions based on Life-Steps, an ART treatment adherence intervention. The comparison condition provided information and supportive counseling. The primary analyses compared adherence (Wisepill and tenofovir plasma levels) at 3 and 6 months. Fifty-eight MSM were screened to enroll 50 participants. Median age was 38.2 years old, 86% were white; 64% had completed college. Wisepill adherence was high in both groups, and not statistically different. Plasma tenofovir levels were significantly higher in the intervention group at 6 months using mean substitution analysis (i.e., computing missing variables) (p = 0.037), however, in the completer analyses (i.e., using only those completing all study visits), there were no statistically significant differences between randomization conditions. Medication adherence was high across a cognitive-behavioral (Life-Steps) and time-matched counseling intervention for PrEP adherence, with some evidence suggesting superiority of Life-Steps in this pilot RCT. Further evaluation in a fully powered efficacy trial is warranted to assess the robustness of this intervention.

Tenofovir 1% vaginal gel for prevention of HIV-1 infection in women in South Africa (FACTS-001): a phase 3, randomised, double-blind, placebo-controlled trial

BACKGROUND

Young women in southern Africa have substantial risk of HIV acquisition. Female-controlled biomedical interventions are needed to mitigate this risk. We aimed to assess the safety and efficacy of a pericoitally applied tenofovir 1% gel.

METHODS

We did a phase 3, double-blind, randomised, placebo-controlled trial at nine community-based clinical trial sites in South Africa to evaluate the safety and efficacy of tenofovir 1% gel. Sexually active women who were HIV negative and aged 18-30 years were enrolled. Participants were randomly assigned (1:1) using sequential participant numbers to either tenofovir 1% gel or a placebo gel (one dose within 12 h before sex and one dose within 12 h after sex [BAT-24 regimen]), using dynamic permuted block sizes of 8 and 16 within each site. Women received monthly HIV-1 testing, risk reduction support, physical examinations, and product dispensing for up to 27 months. The primary efficacy outcome was incident HIV infection and the primary safety outcome was occurrence of grade 2-4 adverse events, both analysed in the modified intention-to-treat population. To assess the efficacy of tenofovir gel, the cumulative probability of HIV infection was calculated for each treatment using the Kaplan-Meier method. This trial is registered with ClinicalTrials.gov, number NCT01386294.

FINDINGS

From Oct 11, 2011, to Aug 29, 2014, 3844 women were screened, 2059 enrolled, and 2029 included in the primary analysis (1032 in the tenofovir group and 1027 in the placebo group); 39 (4%) in the tenofovir group and 36 (4%) in the placebo group were lost to follow-up. 123 HIV-1 infections occurred over 3036 woman-years of observation; 61 in the tenofovir group (HIV incidence 4·0 per 100 woman-years, 95% CI 3·1-5·2) and 62 in the placebo group (4·0 per 100 woman-years, 3·1-5·2; incidence rate ratio [IRR] 0·98, 95% CI 0·7-1·4). A higher incidence of grade 2 adverse events was observed in the tenofovir group than in the placebo group (IRR 1·09, 95% CI 1·0-1·2; p=0·02). The most common grade 2 or higher product-related adverse events were hypophosphataemia (n=22 for tenofovir vs n=22 for placebo), genital symptoms (n=6 for tenofovir vs n=2 for placebo), or elevated transaminases (n=2 for tenofovir vs n=2 for placebo). No product-related serious adverse events were reported, and no differences in product-related adverse events (p=0·78), grade 3 events (p=0·64), or grade 4 events (p=0·74) were observed between treatment groups.

INTERPRETATION

Overall, pericoital tenofovir gel did not prevent HIV-1 acquisition in this population of young women at risk of HIV infection in South Africa. Alternate safe and effective products that are less user dependent than this product or do not require high adherence are needed.

FUNDING

The US Agency for International Development (USAID), the Bill & Melinda Gates Foundation, and the South African Department of Science and Technology and Department of Health.

Pharmacological Measures of Treatment Adherence and Risk of HIV Infection in the VOICE Study

BACKGROUND

None of the 3 regimens tested in the VOICE study showed protection against human immunodeficiency virus (HIV) infection in intent-to-treat analyses. Plasma tenofovir concentrations demonstrated poor adherence to the study product among study subjects. Statistical analyses to explore the causal treatment effect on the prevention of HIV infection among adherent individuals are needed.

METHODS

We developed an analytical strategy to evaluate whether conventional covariate adjustment removes confounding and thereby reveals a prevention effect among adherent individuals. We applied this strategy to the VOICE study, using 2 dichotomized proxy measures of product use: detection of tenofovir in plasma at least once during follow-up and detection of tenofovir in plasma at the 3-month follow-up visit.

RESULTS

After adjustment for a set of baseline predictors of the risk of HIV transmission, the confounding associated with comparison of adherent individuals in the tenofovir gel arm to placebo recipients was nearly eliminated. The relative risk for a prevention effect among those ever having tenofovir detected was 0.53 (P = .038); the relative risk among those having tenofovir detected at 3 months was 0.40 (P = .045).

CONCLUSIONS

A novel regression approach was proposed for causal as-treated analyses in the VOICE study. While intent-to-treat analyses yield null results, this exploratory approach presented evidence suggesting a prevention effect among gel users.

CLINICAL TRIALS REGISTRATION

NCT00705679.

Estimation of HIV incidence in a large, community-based, randomized clinical trial: NIMH project accept (HIV Prevention Trials Network 043)

BACKGROUND

National Institute of Mental Health Project Accept (HIV Prevention Trials Network [HPTN] 043) is a large, Phase III, community-randomized, HIV prevention trial conducted in 48 matched communities in Africa and Thailand. The study intervention included enhanced community-based voluntary counseling and testing. The primary endpoint was HIV incidence, assessed in a single, cross-sectional, post-intervention survey of >50,000 participants.

METHODS

HIV rapid tests were performed in-country. HIV status was confirmed at a central laboratory in the United States. HIV incidence was estimated using a multi-assay algorithm (MAA) that included the BED capture immunoassay, an avidity assay, CD4 cell count, and HIV viral load.

RESULTS

Data from Thailand was not used in the endpoint analysis because HIV prevalence was low. Overall, 7,361 HIV infections were identified (4 acute, 3 early, and 7,354 established infections). Samples from established infections were analyzed using the MAA; 467 MAA positive samples were identified; 29 of those samples were excluded because they contained antiretroviral drugs. HIV prevalence was 16.5% (range at study sites: 5.93% to 30.8%). HIV incidence was 1.60% (range at study sites: 0.78% to 3.90%).

CONCLUSIONS

In this community-randomized trial, a MAA was used to estimate HIV incidence in a single, cross-sectional post-intervention survey. Results from this analysis were subsequently used to compare HIV incidence in the control and intervention communities.

TRIAL REGISTRATION

ClinicalTrials.gov NCT00203749.

Antiretroviral Pre-Exposure Prophylaxis Does Not Enhance Immune Responses to HIV in Exposed but Uninfected Persons

BACKGROUND

Antiretroviral preexposure prophylaxis (PrEP), using daily oral combination tenofovir disoproxil fumarate plus emtricitabine, is an effective human immunodeficiency virus (HIV) prevention strategy for populations at high risk of HIV acquisition. Although the primary mode of action for the protective effect of PrEP is probably direct antiviral activity, nonhuman primate studies suggest that PrEP may also allow for development of HIV-specific immune responses, hypothesized to result from aborted HIV infections providing a source of immunologic priming. We sought to evaluate whether PrEP affects the development of HIV-specific immune response in humans.

METHODS AND RESULTS

Within a PrEP clinical trial among high-risk heterosexual African men and women, we detected HIV-specific CD4(+) and CD8(+) peripheral blood T-cell responses in 10%-20% of 247 subjects evaluated. The response rate and magnitude of T-cell responses did not vary significantly between those assigned PrEP versus placebo, and no significant difference between those assigned PrEP and placebo was observed in measures of innate immune function.

CONCLUSIONS

We found no evidence to support the hypothesis that PrEP alters either the frequency or magnitude of HIV-specific immune responses in HIV-1-exposed seronegative individuals. These results suggest that PrEP is unlikely to serve as an immunologic prime to aid protection by a putative HIV vaccine.

Urine Tenofovir Levels Measured Using a Novel Immunoassay Predict Human Immunodeficiency Virus Protection

New tools are needed to support pre-exposure prophylaxis (PrEP) adherence for human immunodeficiency virus (HIV) prevention, including those that enable real-time feedback. In a large, completed PrEP trial, adequate urine tenofovir levels measured using a novel immunoassay predicted HIV protection and showed good sensitivity and specificity for detectable plasma tenofovir.

Effect of Maternal Obesity on Maternal-Fetal Transfer of Preoperative Cefazolin at Cesarean Section

OBJECTIVES

American Congress of Obstetricians and Gynecologists recommends a single dose of antibiotic prophylaxis before all cesarean sections (C/S). This recommendation is based on pharmacokinetic studies that include only non-obese patients. We sought to evaluate 1) cefazolin plasma concentrations among obese and non-obese patients after administration of a 2-g cefazolin dose for prevention of surgical wound infections, and 2) whether cefazolin concentration in fetal circulation may be protective against pathogens that cause early onset neonatal sepsis.

METHODS

Maternal and fetal cefazolin plasma concentrations were compared between obese (body mass index [BMI] ≥ 30 kg/m²) and non-obese (BMI < 25 kg/m²) healthy, term pregnant women undergoing scheduled C/S. Liquid chromatographic-tandem mass spectrometric (LC-MS/MS) methods were used for quantification of total and free cefazolin concentrations in maternal blood (MB) and umbilical cord blood (UCB).

RESULTS

Eight women were screened and consented. There was no difference between groups in MB total and free cefazolin concentrations. All MB samples had total and free cefazolin concentrations greater than the minimum inhibitory concentration 90 (MIC90) for Group B Streptococcus (GBS), Staphylococcus aureus, and Escherichia coli. All UCB samples had total and free cefazolin concentrations greater than MIC90 for GBS and S aureus, even when administered as briefly as 18 minutes before delivery. A lower concentration of total cefazolin was detected in UCB of neonates of obese women compared to non-obese women (p > 0.05).

CONCLUSIONS

Administration of 2 g of cefazolin to women undergoing scheduled C/S might be an adequate prophylactic dose for surgical wound infection in both non-obese and obese patients; and cefazolin concentration in fetal circulation may be protective against GBS and S aureus.

Low Disclosure of PrEP Nonadherence and HIV-Risk Behaviors Associated With Poor HIV PrEP Adherence in the HPTN 067/ADAPT Study

OBJECTIVE

We evaluated the relationship between 2 types of social relationships, ie, (1) external support for use of HIV pre-exposure prophylaxis (PrEP) and related study supplies and (2) participants' disclosure of PrEP use and condom use and HIV PrEP adherence among daily-dosing regimen participants in HIV Prevention Trials Network (HPTN) 067, an open-label trial of oral tenofovir (TFV) disoproxil fumarate (TDF) 300 mg/emtricitabine (FTC) 200 mg.

METHODS

Using HPTN 067 survey data, we developed scales examining (1) Low Perceived External Support for PrEP: low perceived support by others for PrEP use or perceived negative reactions to the pill case (scoring ranges from 0 to 2) and (2) Participant-Staff Disclosure Challenges Scale, which identifies challenges to sharing nonuse of PrEP or condoms to study staff (scoring ranges from 0 to 4); these scales are the primary independent variables. Adherence, the dependent variable, was determined using log-transformed plasma TFV concentrations. generalized estimating equation (GEE) linear regression was used to assess the association between both scales and adherence.

RESULTS

Participants (n = 161) included HIV-uninfected women in South Africa, and men who have sex with men and transgender women, in Thailand and the United States. In multivariable analyses, higher scores in the Participant-Staff Disclosure Challenges Scale were significantly associated with lower PrEP adherence [exp(β) = 0.62, 95% CI: (0.46 to 0.84); P = 0.002] as were increased days since the last PrEP dose [exp(β) = 0.73, 95% CI: (0.65 to 0.83); P ≤ 0.001].

CONCLUSIONS

Given the association with adherence, study staff-participant interactions and participants' disclosure of PrEP challenges may be worthwhile intervention targets for improving PrEP adherence in confirmatory studies.

Optimizing Pre-Exposure Antiretroviral Prophylaxis Adherence in Men Who Have Sex with Men: Results of a Pilot Randomized Controlled Trial of "Life-Steps for PrEP"

Antiretroviral pre-exposure prophylaxis (PrEP) has been demonstrated to decrease HIV acquisition in multiple efficacy trials, but medication adherence is critical, and was suboptimal in several studies. Fifty HIV-uninfected at risk men who have sex with men (MSM) were randomized to a cognitive behavioral intervention condition or a time and session-matched comparison counseling intervention. The experimental intervention entailed four nurse-delivered initial and two booster sessions based on Life-Steps, an ART treatment adherence intervention. The comparison condition provided information and supportive counseling. The primary analyses compared adherence (Wisepill and tenofovir plasma levels) at 3 and 6 months. Fifty-eight MSM were screened to enroll 50 participants. Median age was 38.2 years old, 86% were white; 64% had completed college. Wisepill adherence was high in both groups, and not statistically different. Plasma tenofovir levels were significantly higher in the intervention group at 6 months using mean substitution analysis (i.e., computing missing variables) (p = 0.037), however, in the completer analyses (i.e., using only those completing all study visits), there were no statistically significant differences between randomization conditions. Medication adherence was high across a cognitive-behavioral (Life-Steps) and time-matched counseling intervention for PrEP adherence, with some evidence suggesting superiority of Life-Steps in this pilot RCT. Further evaluation in a fully powered efficacy trial is warranted to assess the robustness of this intervention.

Correlates of self-reported and biomarker based adherence to daily oral HIV pre-exposure prophylaxis among a cohort of predominantly men who have sex with men in Nigeria

INTRODUCTION

HIV pre-exposure prophylaxis (PrEP) significantly reduces the risk of HIV acquisition. However, studies have demonstrated discordance between self-reported measures and biomedical benchmarks of PrEP adherence. We estimated the correlation between self-reported PrEP adherence and PrEP biomarkers and explored factors associated with adherence among men who have sex with men (MSM) in Nigeria.

METHODS

TRUST-PrEP, an open-label, prospective study; conducted in Abuja between April 2018 and May 2019. MSM ≥ 18 years with substantial HIV risk were enrolled. Participants reported PrEP adherence in the last month using a 4-point scale from "poor" to "perfect" and serum samples for PrEP biomarkers were collected at months 3 and 9. Serum tenofovir concentration was measured by liquid chromatography-tandem mass spectrometry and considered protective for adherence if ≥ 4.2 ng/ml. Spearman's rank correlation was used to estimate correlation between self-reported adherence and measured tenofovir levels. Generalized estimating equations with a logit link was used to estimate adjusted odds ratios (aORs) and 95% confidence intervals (CIs) for associations between self-reported adherence and laboratory-measured adherence.

RESULTS

A total of 219 MSM with median age 23 (interquartile range 20-27) years had at least one PrEP biomarker assay. Only 66/219 (30%) had at least one record of protective tenofovir concentration. Correlation between tenofovir and self-reported adherence at 3 and 9 months were 0.1 and 0.02 respectively. Furthermore, 17/219 (8%,) and 49/219 (22%) had serum tenofovir of 4.2-35.4 ng/mL and ≥ 35.5 ng/mL, corresponding to at least 4 and 7 days' PrEP use in a week, respectively. PrEP adherence was higher among participants introduced to PrEP in the clinics compared with communities (aOR: 8.35, 95%CI: [3.24, 21.5]) and those with same-sex practices family disclosure (aOR: 3.60 95% CI: [1.73, 7.51]).

CONCLUSION

Self-reported PrEP adherence poorly correlated with biomarkers. Facilitating clinic-based PrEP introduction and disclosure of same-sex practices to family among MSM may improve PrEP adherence.

Rectal Douche as HIV Pre-Exposure Prophylaxis for Receptive Anal Intercourse: An End User Tenofovir Powder Sachet Preparation Feasibility Study (DREAM-04)

BACKGROUND

Unprotected receptive anal intercourse carries the highest sexual HIV transmission risk. The need for diverse pre-exposure prophylaxis (PrEP) options has encouraged the development of on-demand, topical PrEP products for those preferring nonsystemic or occasional PrEP. We assessed end users' proficiency in preparing tenofovir douches from sachets containing 2 different powder types, lyophilized and spray dried, and evaluated their experience.

METHODS

Cisgender adult men with a history of RAI-related douching were consented, screened, and randomized 1:1 to the order of the powder type prepared. All participants prepared at least 3 enema bottles of each powder type. Aliquots from each prepared douche bottle were analyzed for tenofovir (TFV) concentration, osmolality, and pH. User experience and likelihood of future product use were assessed by questionnaire.

RESULTS

Twenty-one eligible participants were enrolled. Most participants reported both products as easy or very easy to prepare and likely or very likely to be used. Participants preferred the lyophilized product. The lyophilized and spray-dried douche bottles prepared met the osmolality specifications 89% and 61% of the time and TFV content specifications 81% and 29% of the time, respectively. Questionnaires indicated the most common challenges were tearing open the sachets and transferring the spray-dried product.

CONCLUSIONS

Most participants reported the douches were easy to prepare and indicated likely future use. Although the lyophilized sachets were prepared sufficiently to establish preparation feasibility, the spray-dried sachets often fell outside specifications. Failure analysis provided insights to guide product modifications to improve the proficiency of douche preparation and future product use.

Strengthening the Application of the DAIDS GCLP Guidelines: The Implementation of an Integrated Laboratory Oversight Framework

The Division of AIDS (DAIDS) Good Clinical Laboratory Practice (GCLP) Guidelines establish a framework to guide the oversight of laboratories supporting DAIDS-sponsored clinical research or trials. Compliance with these guidelines promotes data reliability, validity, and safety of the clinical research or trial participants and laboratory staff and ensures adherence to regulatory requirements. Acknowledgment and adoption of the DAIDS GCLP Guidelines are critical in building laboratory capacity and preparedness for conducting clinical trials. In collaboration with DAIDS, laboratory experts support the implementation of the DAIDS Integrated Laboratory Oversight Framework (Framework) activities. This article describes the implementation of the GCLP Guidelines, the Framework activities, and the coordinated efforts to strengthen laboratory performance. The Framework activities include four components: Quality Assurance Oversight, GCLP Audits, GCLP Training, and Laboratory Quality Improvement. Comparison of GCLP Guidelines with other regulations or standards, including U.S. Clinical Laboratory Improvement Amendments regulation 42 CFR 493, College of American Pathologists, World Health Organization GCLP, and International Organization for Standardization, ISO 15189:2012 standards, highlighted the differences and similarities to guide integration and harmonization efforts. Processes related to the Framework activities are outlined in detail, including key data derived from the managed activities of over 175 laboratories worldwide. Via the evolution of the DAIDS GCLP Guidelines and laboratory oversight workflows, the laboratories participating in DAIDS-sponsored clinical research and trials have successfully participated in internal and external regulatory audits. The collaborative and integrated oversight approach promotes knowledge-sharing and accountability to support the implementation of the DAIDS GCLP Guidelines and compliance monitoring. Lessons learned have helped with the implementation of the DAIDS integrated laboratory oversight approach and quality oversight programs at multiple laboratories worldwide.

Safety, tolerability, and acceptability of long-acting injectable cabotegravir for HIV prevention in cisgender female adolescents (HPTN 084-01): a single-arm, open-label, phase 2b trial

BACKGROUND

Long-acting formulations of HIV pre-exposure prophylaxis (PrEP) appear particularly well suited to adolescents. We aimed to establish the safety, tolerability, and acceptability of long-acting injectable cabotegravir as PrEP in cisgender adolescent girls.

METHODS

HPTN 084-01 is a single-arm, open-label, phase 2b trial conducted at three clinical research sites in South Africa, Uganda, and Zimbabwe. Girls were recruited via community study-outreach teams, reproductive health clinics, and peer referral. Sexually active adolescent girls (younger than 18 years) willing to use long-acting contraception, weighing at least 35 kg, and able to participate with parental or guardian consent (unless an emancipated minor) were eligible. After an oral lead-in, if no adverse events occurred, participants received a 3 mL intramuscular gluteal injection (long-acting injectable cabotegravir 600 mg) at weeks 5, 9, 17, 25, and 33. The product was discontinued for grade 3 or higher toxic effects or pregnancy. The primary outcomes were safety, tolerability, and acceptability. Safety (ie, proportions of grade 2 or higher clinical and laboratory events) was assessed at weeks 6, 10, 18, 26, and 34 in all enrolled participants. Injection tolerability (ie, proportions of premature discontinuation due to intolerability, frequency of injections, or burden of study procedures) and product acceptability (ie, proportions of scheduled injections completed and participants preferring long-acting injectable cabotegravir for future use) were assessed in all participants who received at least one injection at study end. The trial was registered with ClinicalTrials.gov (NCT04824131) and is completed.

FINDINGS

Between Nov 1, 2020, and Aug 31, 2021, 69 participants were assessed for eligibility and 55 met inclusion criteria. The mean age was 16·0 years (SD 1·1), 39 (71%) had a recent primary sexual partner, 12 (22%) reported transactional sex, and 22 (40%) had sexually transmitted infections at baseline. Two participants dropped out and did not initiate long-acting injectable cabotegravir due to adverse events unrelated to the study drug during the oral lead-in. One participant stopped long-acting injectable cabotegravir after three injections due to pregnancy. 51 (93%) participants reported at least one adverse event of grade 2 or higher, mostly unrelated, transient laboratory abnormalities. There were no long-acting injectable cabotegravir discontinuations due to intolerability. Of the 52 participants who completed step 2, all scheduled injections were completed and 32 (62%) participants reported they would consider using long-acting injectable cabotegravir for HIV prevention in the future.

INTERPRETATION

Long-acting injectable cabotegravir is a safe, tolerable, and acceptable option for the prevention of HIV in adolescent girls. Our study findings expand the HIV prevention options available to adolescent girls.

FUNDING

National Institute of Allergy and Infectious Diseases, National Institute of Mental Health, National Institute on Drug Abuse, the Eunice Kennedy Shriver National Institute of Child Health and Human Development, ViiV Healthcare, and The Bill & Melinda Gates Foundation.

Influence of Participant Perceptions of Adherence-Related Interactions with Study/Study Team on Drug Levels: HPTN069 Analysis of Self-Reported Adherence Experiences While on Study

Adherence to HIV pre-exposure prophylaxis (PrEP) study drug is critical for safety, tolerability, and efficacy trials, and may be affected by how adherence is communicated by the study staff to trial participants. Increasingly, clinical trials investigating PrEP are creating and implementing 'participant-centered' approaches that discuss potential non-adherence neutrally (without negative judgement) and support efforts to adhere versus insisting on perfect adherence. In the HPTN069/ACTG A5305 study, we evaluated participant experiences of potentially negative adherence-related interactions with study teams using ten items to characterize the frequency of such experiences. We related these individual items and a combined set of seven negative experience items (total negative experience score) to drug concentrations (detectable or consistent with daily-dosing). The exploratory analyses used logistic regression for each experience item on the full sample and disaggregated by sex. Several experiences were related to drug detection and to daily-dosing, although more so for participants identifying as men than women. Total negative experience scores associated with not having detection drug concentrations for the full sample, and remained significant even when controlling for sex, age, and race. Daily dosing was associated with total negative experience score for men in the sample. Additional investigations into adherence-related interactions with study teams that are most problematic or helpful in general and uniquely for men and women are warranted.