Emtricitabine-tenofovir concentrations and pre-exposure prophylaxis efficacy in men who have sex with men

Incentivizing adherence to pre-exposure prophylaxis for HIV prevention: a randomized pilot trial among male sex workers in Mexico

Low adherence to preventative medications against life-long health conditions is a major contributor to global morbidity and mortality. We implemented a pilot randomized controlled trial in Mexico to measure the extent to which conditional economic incentives help male sex workers increase their adherence to pre-exposure prophylaxis (PrEP) for HIV prevention. We followed n = 110 male sex workers over 6 months. At each quarterly visit (at months 0, 3, and 6), all workers received a $10 transport reimbursement, a free 3-month PrEP supply, and completed socio-behavioral surveys. The primary outcome was an objective biomarker of medication adherence based on tenofovir (TFV) drug concentration levels in hair collected at each visit. Individuals randomized to the intervention received incentives based on a grading system as a function of PrEP adherence: those with high (> 0.043 ng/mg TFV concentration), medium (0.011 to 0.042 ng/mg), or low (< 0.011 ng/mg) adherence received $20, $10, or $0, respectively. Six-month pooled effects of incentives on PrEP adherence were analyzed using population-averaged gamma generalized estimating equation models. We estimated heterogeneous treatment effects by sex worker characteristics. The incentive intervention led to a 28.7% increase in hair antiretroviral concentration levels over 6 months consistent with increased PrEP adherence (p = 0.05). The effect of incentives on PrEP adherence was greater for male sex workers who were street-based (vs. internet) workers (p < 0.10). These pilot findings suggest that modest conditional economic incentives could be effective, at scale, for improving PrEP adherence among male sex workers, and should be tested in larger implementation trials. ClinicalTrials.gov Identifier: NCT03674983.

HIV-1 infection kinetics, drug resistance, and long-term safety of pre-exposure prophylaxis with emtricitabine plus tenofovir alafenamide (DISCOVER): week 144 open-label extension of a randomised, controlled, phase 3 trial

BACKGROUND

Data characterising the long-term use and safety of emtricitabine plus tenofovir disoproxil fumarate as daily oral pre-exposure prophylaxis (PrEP) are scarce and there are uncertainties regarding the value of routine HIV-1 RNA testing during oral PrEP follow-up.

METHODS

The DISCOVER trial was a randomised, controlled, phase 3 trial in which cisgender men and transgender women aged 18 years and older with a high likelihood of acquiring HIV were recruited from 94 clinics in Europe and North America and randomly assigned to receive either emtricitabine plus tenofovir disoproxil fumarate (200/25 mg) tablets daily, with matched placebo tablets, or emtricitabine plus tenofovir alafenamide (200/300 mg) tablets daily, with matched placebo tablets, for at least 96 weeks. After completion of the trial, participants were offered enrolment in this 48-week open-label extension study of emtricitabine plus tenofovir alafenamide. In participants diagnosed with HIV during the randomised and open-label phases of the study, we characterised HIV-1 test results and measured HIV-1 RNA viral load retrospectively when available. Adherence based on tenofovir diphosphate concentrations in dried blood spots and genotypic resistance were assessed in participants diagnosed with HIV. Safety assessments included adverse events, laboratory parameters, and, in a subset of participants, bone mineral density. HIV-1 incidence in participants initially randomly assigned to receive emtricitabine plus tenofovir alafenamide was estimated using a Poisson distribution. Changes from baseline in safety endpoints were described in participants assigned to received emtricitabine plus tenofovir alafenamide and in those who switched from emtricitabine plus tenofovir disoproxil fumarate during the open-label phase. This trial is registered with ClinicalTrials.gov, NCT02842086, and is ongoing.

FINDINGS

Between Sept 13, 2016, and June 30, 2017, 5399 participants were enrolled and randomly assigned in DISCOVER. 2699 were assigned to receive emtricitabine plus tenofovir disoproxil fumarate and 2700 were assigned to receive emtricitabine plus tenofovir alafenamide, of whom 2693 and 2694, respectively, received at least one dose of study drug. 2115 (79%) assigned to emtricitabine plus tenofovir disoproxil fumarate switched to emtricitabine plus tenofovir alafenamide in the open-label phase, and 2070 (77%) continued with emtricitabine plus tenofovir alafenamide in the open-label phase. As of data cutoff (Dec 10, 2020), after 15 817 person-years of follow-up, 27 new HIV-1 diagnoses were observed across the total study period, with three occurring during the open-label phase. In participants who were initially assigned to emtricitabine plus tenofovir alafenamide, the incidence was 0·13 per 100 person-years (95% CI 0·061-0·23; ten of 2670). Stored plasma samples were available for 23 of 27 participants, including 22 with incident infection. In four (17%) of 23 participants, retrospective testing detected HIV-1 RNA before serological HIV-1 test positivity; one was a suspected baseline infection. Of the three incident cases, all three were non-adherent to PrEP and none developed drug resistance. Among participants taking emtricitabine plus tenofovir alafenamide for up to 144 weeks, markers of glomerular filtration and proximal renal tubule dysfunction (β2-microglobulin to creatinine ratio and retinol-binding protein to creatinine ratio) improved or remained stable at 144 weeks compared with baseline, bone mineral density in hip and lumbar spine increased or remained stable from baseline to week 144 (n=191), cholesterol and glucose concentrations remained stable, and median bodyweight increased by less than 1 kg per year. In participants who switched from emtricitabine plus tenofovir disoproxil fumarate during the open-label phase (2115 [79%] of 2693), markers of glomerular filtration and proximal renal tubule dysfunction improved or remained stable, bone mineral density increased, cholesterol concentrations increased, glucose concentrations were similar, and median bodyweight increased more compared with those who remained on emtricitabine and tenofovir alafenamide.

INTERPRETATION

Routine HIV-1 RNA testing for follow-up of individuals on daily oral PrEP provides modest additional clinical benefit. Long-term use of emtricitabine and tenofovir alafenamide as daily oral PrEP is safe and well tolerated and can be an especially appropriate choice for people with bone or renal morbidities.

FUNDING

Gilead Sciences.

Leveraging A Digital Pill System to Understand Prevention-Effective Adherence to Oral Hiv Pre-Exposure Prophylaxis Among Men Who Have Sex with Men with Substance Use

Daily oral pre-exposure prophylaxis (PrEP) is highly effective for HIV prevention, though efficacy depends on adherence. Digital pill systems (DPS) can enable direct, real-time adherence measurement. HIV-negative men who have sex with men (MSM) with substance use (excluding alcohol) utilized a DPS over 90 days and completed weekly surveys reporting sexual activity, condom use, and substance use. Responses indicating (1) any sexual activity and substance use or (2) condomless anal intercourse (CAI) in the prior week were categorized as high risk for HIV acquisition. PrEP adherence data for the 7-day period preceding each response was dichotomized as ≤ 3 and ≥ 4 doses/week, indicating prevention-effective adherence, and compared by HIV risk level. Thirteen MSM were analyzed (median age: 32). Of 113 surveys, 48.7% indicated high HIV risk, with 12.4% reporting CAI alone, 16.8% any sexual activity and substance use, and 19.5% both CAI and substance use. Weekly mean PrEP adherence was 90.3% (6.3 of 7 doses/week), with ≥ 4 doses/week recorded during 92.0% of weeks. The proportion of participants with ≥ 4 recorded doses/week was 88.9% during weeks with CAI alone, 89.5% during weeks with any sexual activity and substance use, 92.0% during weeks with both CAI and substance use, and 92.8% during lower risk weeks. Participants ingested ≥ 4 doses/week during 89.1% of all high-risk weeks and 94.8% of low-risk weeks. Overall, participants maintained high levels of PrEP adherence while engaging in HIV risk behaviors. DPS can be deployed concurrently with data collection tools to assess ingestion patterns during periods of elevated risk.

Prepare Romania: study protocol for a randomized controlled trial of an intervention to promote pre-exposure prophylaxis adherence and persistence among gay, bisexual, and other men who have sex with men

BACKGROUND

Gay, bisexual, and other men who have sex with men (GBMSM) represent a high-risk group for HIV transmission in Romania, yet they possess few resources for prevention. Despite having no formal access to pre-exposure prophylaxis (PrEP) through the health system, GBMSM in Romania demonstrate a high need for and interest in this medication. In anticipation of a national rollout of PrEP, this study tests the efficacy of a novel strategy, Prepare Romania, that combines two evidence-based PrEP promotion interventions for GBMSM living in Romania.

METHODS

This study uses a randomized controlled trial design to examine whether GBMSM living in Romania receiving Prepare Romania, a culturally adapted counseling and mobile health intervention (expected n = 60), demonstrate greater PrEP adherence and persistence than those assigned to a PrEP education control arm (expected n = 60). Participants from two main cities in Romania are prescribed PrEP and followed-up at 3 and 6 months post-randomization. PrEP adherence data are obtained through weekly self-report surveys and dried blood spot testing at follow-up visits. Potential mediators (e.g., PrEP use motivation) of intervention efficacy are also assessed. Furthermore, Prepare Romania's implementation (e.g., proportion of enrolled participants attending medical visits, intervention experience) will be examined through interviews with participants, study implementers, and healthcare officials.

DISCUSSION

The knowledge gained from this study will be utilized for further refinement and scale-up of Prepare Romania for a future multi-city effectiveness trial. By studying the efficacy of tools to support PrEP adherence and persistence, this research has the potential to lay the groundwork for PrEP rollout in Romania and similar contexts. Trial registration This study was registered on ClinicalTrials.gov, identifier NCT05323123 , on March 25, 2022.

Using GPS-defined venue-based affiliation networks among Black sexually minoritized men and transgender women to identify locations for HIV prevention interventions

PURPOSE

HIV biomedical intervention uptake is suboptimal among Black sexually minoritized men (SMM) and transgender women (TW). Venues where people meet and interact shape HIV-related risk and prevention behaviors. We aimed to construct GPS-defined venue-based affiliation networks and identify the unique set of venues that could maximize reach of HIV biomedical interventions among Black SMM and TW.

METHODS

We used baseline survey and GPS data from 272 Black SMM and TW in the Neighborhoods and Networks (N2) Cohort Study in Chicago, Illinois (2018-2019). We mapped participants' GPS data to the nearest pre-identified SMM- and TW-friendly venue (n = 222) to construct affiliation networks. Network analyses were performed to identify influential venues that can yield high reach to intervention candidates.

RESULTS

Participants were affiliated with 75.5 % of all pre-identified venues based on GPS data. Two influential venues were identified in the non-PrEP use network, which when combined, could reach 52.5 % of participants not taking PrEP. Participants that could be reached through these two influential venues reported more non-main sex partners than participants not affiliated with either venue (p = 0.049).

CONCLUSION

We demonstrate a potential for GPS-defined venue-based affiliation networks to identify unique combinations of venues that could maximize the impact of HIV prevention interventions.

Parent Facilitation of Condom Access and HIV Testing Associated with Improved Sexual Health Outcomes for Sexual Minority Young Men

Sexual minority young men experience a high HIV incidence. Parent-based interventions are promising for prevention efforts, but further research is needed to identify specific, replicable parental behaviors associated with improved sexual health outcomes for sexual minority young men. We assessed parental behaviors in the domains of facilitating access to condoms, providing instruction in condom use, and supporting HIV testing, and tested whether parental behaviors were associated with sons' condom use self-efficacy and intentions to get tested for HIV. Data came from the baseline assessment of a pilot trial of a parent-based HIV prevention program, and participants were dyads (n = 61) of sexual minority young men (M. age: 16.87; 46% racial/ethnic minority) and their parents (M. age: 44.31; 26% racial/ethnic minority). Parents and sons reported on parental behaviors in each domain. Results indicated that parents' facilitation of access to condoms was associated with sons' condom use self-efficacy, and parents' facilitation of HIV testing was associated with sons' HIV testing intentions. Findings were robust across both parent and son reports of parental behaviors. Parental condom use instruction was unrelated to sons' condom use self-efficacy. Findings suggest that parent-based HIV prevention programs for sexual minority young men should encourage parents to provide instrumental assistance to their sons in accessing condoms and HIV testing. There is a need for further research to identify underlying mechanisms.

Longitudinal evolution of the HIV effective reproduction number following sequential expansion of treatment as prevention and pre-exposure prophylaxis in British Columbia, Canada: a population-level programme evaluation

BACKGROUND

Treatment as prevention and pre-exposure prophylaxis (PrEP) are key strategies in the control of HIV/AIDS. We aimed to characterise the longitudinal effects of antiretroviral therapy (ART), followed by treatment as prevention and the addition of PrEP, on the HIV effective reproduction number (Re) in British Columbia, Canada.

METHODS

This population-level programme evaluation used data from the Drug Treatment Program of the British Columbia Centre for Excellence in HIV/AIDS (Vancouver, British Columbia, Canada). We also used estimates of HIV incidence and prevalence from the Public Health Agency of Canada, data on the number of new HIV diagnoses per year from the British Columbia Centre for Disease Control, and mortality data from the British Columbia Vital Statistics Agency. Data were obtained from 1985 until 2022, depending on the database source. Outcomes were the annual HIV prevalence, HIV incidence, number of new HIV diagnoses, number of people living with HIV on ART, HIV/AIDS-related and all-cause mortality rates, the HIV incidence-to-all-cause-mortality ratio, and Re. We calculated the modified effective reproduction number (Rme) using two thresholds of viral suppression and compared these values with Re.

FINDINGS

We found a 95% decline in HIV/AIDS-related mortality and a 91% decrease in HIV incidence over the study period. The Re progressively declined from 1996 to 2022; however, from 1996 to 2017, Rme remained stable (>1) when calculated for people living with HIV with unsuppressed viraemia, suggesting that treatment as prevention reduces HIV incidence by decreasing the pool of individuals who are potentially able to transmit the virus. From 2018 to 2022, a decline in the estimated Re and Rme (<1) was observed regardless of whether we considered all people living with HIV or only those who were virologically unsuppressed. This finding suggests that PrEP decreases HIV incidence by reducing the number of susceptible individuals in the community, independently of viral suppression.

INTERPRETATION

Our results show the synergy between generalised treatment as prevention and targeted PrEP in terms of decreasing HIV incidence. These findings support the incorporation of longitudinal monitoring of Re at a programmatic level to identify opportunities for the optimisation of treatment-as-prevention and PrEP programmes.

FUNDING

British Columbia Ministry of Health, Health Canada, Public Health Agency of Canada, Vancouver Coastal Health, Vancouver General Hospital Foundation, Genome British Columbia, and the Canadian Institutes of Health Research.

Incidence and factors associated with PrEP discontinuation in France

OBJECTIVES

HIV pre-exposure prophylaxis (PrEP) is effective in preventing HIV, but some seroconversions occur due to poor adherence or PrEP discontinuation. Our objective was to estimate the incidence of PrEP discontinuation and describe the reasons and factors associated with discontinuations.

METHODS

A retrospective cohort was conducted in three French hospitals between January 2016 and June 2022. PrEP users who attended at least twice within 6 months during study period were included and followed up until December 2022. The incidence rate of PrEP discontinuation was estimated by censoring lost to follow up individuals. Factors associated with PrEP discontinuations were identified using a multivariate Cox model.

RESULTS

A total of 2785 PrEP users were included, with 94% men and 5% transgender people. Median age was 35 years. By December 2022, 653 users had stopped PrEP (24%). The incidence rate was 10.8 PrEP discontinuations for 100 person-years (PY). The main causes of discontinuation were being in a stable relationship (32%), and not judging the treatment useful anymore (12%). Individuals who discontinued PrEP were younger [<29, HR = 1.45 (1.17-1.80)], and more likely to be women [HR = 2.44 (1.50-3.96)] or sex workers [HR = 1.53 (0.96-2.44)]. They were more likely to report PrEP side effects [HR = 2.25 (1.83-2.77)] or ≥2 sexually transmitted infections [HR = 1.87 (1.53-2.27)] during the last year.

CONCLUSION

The incidence of PrEP discontinuations was quite low compared to rates observed in other cohorts. Users who stopped PrEP were sometimes still exposed to HIV, emphasizing the need for targeted interventions to prepare and support PrEP discontinuations and limit seroconversion risk.

Dynamics of HIV PrEP use and coverage during and after COVID-19 in Germany

BACKGROUND

Pre-exposure prophylaxis (PrEP) with oral emtricitabine/tenofovir disoproxil (FTC/TDF) proved highly efficient in preventing HIV. Since 09/2019, FTC/TDF-PrEP is covered by health insurances in Germany, if prescribed by licensed specialists. However, methods to longitudinally monitor progress in PrEP implementation in Germany are lacking.

METHODS

Utilizing anonymous FTC/TDF prescription data from 2017-2021, we developed a mathematical model to disentangle HIV-treatment from PrEP prescriptions, as well as to translate PrEP prescriptions into number of PrEP users. We used the model to estimate past- and future PrEP uptake dynamics, to predict coverage of PrEP needs and to quantify the impact of COVID-19 on PrEP uptake on a national and regional level.

RESULTS

We identified significant (p<0.01) decelerating effects of the first- and second COVID-19-lockdown on PrEP uptake in 04/2020 and 12/2020. We estimated 26,159 (CI: 25,751-26,571) PrEP users by 12/2021, corresponding to 33% PrEP coverage of people in need. We projected 64,794 (CI: 62,956-66,557) PrEP users by 12/2030, corresponding to 81% PrEP coverage. We identified profound regional differences, with high PrEP coverage and uptake in metropoles and low coverage in more rural regions.

CONCLUSIONS

Our approach presents a comprehensive solution to monitor and forecast PrEP implementation from anonymous data and highlighted that the COVID-19 pandemic significantly decelerated PrEP uptake in Germany. Moreover, slow PrEP uptake in rural areas indicate that structural barriers in PrEP care, education or information exist that may hamper the goal of ending the AIDS epidemic by 2030.

Person-Centered Coordinated Care Experience of People With Long-Term Conditions in the Balearic Islands Measured by the P3CEQ

Objective

This study aimed to use the Person-Centered Coordinated Care Experience Questionnaire (P3CEQ) to assess the experience of person-centered coordinated care among people with long-term conditions in the Balearic Islands, Spain.

Methods

Over 1300 participants receiving treatment for chronic conditions or HIV pre-exposure prophylaxis were invited to complete the P3CEQ and a socio-demographic questionnaire, both administered electronically via the Naveta app. The P3CEQ assesses the key domains of the P3C through an 11-item questionnaire. Items 1, 2, 3, 4, 5, 8, 9 and 10 assess specifically person-centredness (PC subscale), while items 5, 6, 7, 8 and 9 measure care coordination (CC subscale; question 7 includes 4 sub-questions to specifically assess care plans). Descriptive statistics were used to summarize patient characteristics and P3CEQ items scores. Data analysis included chi-squared test of independence, Student's t-test and analysis of variance test. Pairwise comparisons were adjusted by Bonferroni correction.

Results

The P3CEQ and a socio-demographic questionnaire were sent to 1313 individuals (651 men, 657 women, 5 'other gender'). A response rate of 35.34% was achieved, with 464 P3CEQ responders (223 men and 241 women). Significant differences in response rates were observed by age, smoking status, alcohol consumption, membership of patient organizations, and use of alternative medicine. Care planning was rated significantly lower than other measured domains. Women experienced less person-centered care than men (16.64 vs 17.91) and rated care coordination worse than their male counterparts (9.18 vs 10.23). There were also differences in scores between medical condition types, with cancer and inflammatory bowel disease patients rating highest for both person-centered care (21.20 and 19.13, respectively) and care coordination (10.70 vs 10.88, respectively). Patients with skin and rheumatic diseases rated lowest their experience of person-centered care. People with higher education and those employed or studying experienced better person-centeredness.

Conclusion

Using the P3CEQ, we detected significant differences in the care experiences of people with chronic conditions, suggesting the need to address potential gender biases, social inequalities, and the poorer ratings observed for certain conditions in the study population.

Integrating sexual and reproductive health into pre-travel consultations

BACKGROUND

Casual sex during travel is a major preventable factor in the global transmission of sexually transmissible infections (STI). Pre-travel consults present an excellent opportunity for practitioners to educate travellers about sexual and reproductive health (SRH) and safety. This scoping review aims to explore and understand the extent to which SRH is included in pre-travel consultations.

METHODS

PubMed, Embase, Cumulative Index to Nursing and Allied Health Literature, Scopus, Medline and Web of Science were systematically searched for primary research articles exploring whether health care practitioners (HCP) included SRH in pre-travel consultations. Extracted findings were synthesized and presented in narrative form.

RESULTS

Findings across 13 articles suggest HCPs infrequently broached SRH in pre-travel consultations with HCP discomfort, and lack of time and resources presented as key barriers. Urban practice settings, HCP experience, training in travel medicine and traveller characteristics such as sexual orientation were positively associated with discussions about SRH. SRH advice reported was general in nature, primarily focusing on safer sex, condoms or unspecified STI advice. Risk assessments based solely on age or stereotypes around sexual preferences led to key aspects of SRH care being missed for some (e.g. SRH was less likely to be discussed with older travellers).

CONCLUSIONS

HCPs frequently miss opportunities to integrate SRH into pre-travel consultations. Strategies to promote HCP confidence and awareness present a promising means to boost the frequency and quality of SRH advice disseminated. Integrating culturally safe and responsive SRH history-taking and advice into pre-travel consultations may contribute to global reductions in STI transmission and promote traveller SRH well-being.

Behind Prep Decisions: Understanding User Patterns and Discontinuation Factors in Real-World

This study aimed to characterize the epidemiological aspects of PrEP use and barriers to accessing this prophylaxis. This cross-sectional study was conducted between January 2021 and April 2022, encompassing 140 PrEP users treated at the Testing and Counseling Center (CTA) in Campo Grande, Mato Grosso do Sul. Data on sociodemographic characteristics and factors associated with PrEP discontinuation were obtained using a standardized questionnaire. Most PrEP users were cisgender men (92.00%), predominantly white (51.00%), over 30 years of age (56.50%), homosexual-oriented (76.50%), and had a minimum of 12 years of education (77.50%). Approximately 60.00% admitted to inconsistent condom use in recent sexual encounters, primarily involving anal intercourse. Approximately 88.00% perceived themselves as at risk of contracting STIs in the upcoming year. Regarding new presentation forms, 54.00% indicated a willingness to use "on-demand PrEP," and 92.00% expressed interest in using "injectable PrEP." After 6 months of follow-up, 43.60% (95.00% CI: 35.50-52.00) discontinued PrEP use, primarily due to changes in sexual behavior (38.30%) and difficulties accessing healthcare services (21.28%). This study underscores the need to involve diverse key populations and highlights the significance of PrEP as an ongoing monitoring strategy for HIV/STI prevention in addition to the importance of incorporating new formulations such as daily oral PrEP into the Brazilian National Health System (SUS).

Interventions to Improve Adherence to Oral Pre-exposure Prophylaxis: A Systematic Review and Network Meta-analysis

For people at risk of HIV infection, pre-exposure prophylaxis (PrEP) can reduce the risk of infection in anticipation of exposure to HIV. The effectiveness of PrEP relies upon a user's adherence to their PrEP regimen. We sought to assess the effect of PrEP adherence interventions compared to usual care or another intervention for people at risk of HIV. We searched electronic databases from 2010 onwards for randomized controlled trials (RCTs) involving persons at risk of HIV randomized to an adherence promoting intervention vs usual care or another intervention. We used network meta-analyses to compare PrEP adherence for all participant populations. Certainty of evidence was assessed using Confidence in Network Meta-Analysis (CINeMA). 21 trials (N = 4917) were included in qualitative analysis (19 in network meta-analyses (N = 4101)). HIV self-testing interventions with adherence feedback elements improved adherence compared to usual care (risk ratio (RR): 1.83, 95%CI 1.19, 2.82). In contrast, HIV self-testing alone was inferior to HIV self-testing with adherence feedback (RR: 0.58, 95%CI 0.37-0.92). Reminders alone also were inferior to HIV self-testing with adherence feedback on adherence (RR: 0.53, 95%CI 0.34-0.84) and had similar effects on adherence as usual care (RR: 0.98, 95%CI: 0.86-1.11). Interventions with only one component were inferior for adherence than those with two components (RR: 0.74, 95%CI 0.62-0.88) and those with three components (RR: 0.78, 95%CI 0.65-0.93). The certainty of evidence was moderate for HIV self-testing plus adherence feedback and interventions with two or three components. When designing future PrEP adherence interventions, we recommend strategies with more than one but no more than three components.

"That's My Girl; I love her": The Promise of Compassionate, Inclusive Healthcare for Black Transgender Women to Support PrEP Use

There are significant disparities in HIV pre-exposure prophylaxis (PrEP) use that disproportionately impact Black transgender women. Medical mistrust and discriminatory experiences in healthcare settings have been identified as critical barriers to equitable PrEP implementation. This qualitative study examines Black transgender women's experiences in healthcare to better understand how patient-provider relationships can help overcome the challenges brought on by medical mistrust. We interviewed 42 Black transgender women about their experiences with healthcare and PrEP access. Data were analyzed using inductive thematic content analysis to develop the following themes: (1) historical and ongoing marginalization and exclusion from healthcare remains a barrier to PrEP use; (2) Many providers continue to be unprepared to prescribe PrEP; (3) Providers can act as important advocates and sources of support; and (4) Compassionate, trusting patient-provider relationships can facilitate PrEP use. Our results highlight the importance of supportive and positive patient-provider relationships and demonstrate how providers can build trusting relationships with Black transgender women to help overcome barriers to healthcare and PrEP use.

Establishing adherence-concentration-efficacy thresholds of TDF-FTC pre-exposure prophylaxis for HIV prevention in African women: a protocol for the Women TDF-FTC Benchmark Study

Background

Oral pre-exposure prophylaxis (PrEP) using co-formulated emtricitabine (FTC) and tenofovir disoproxil fumarate (TDF) is a potent HIV prevention method for men and women, with its efficacy highly dependent on adherence. A pivotal HIV efficacy study combined with a directly observed pharmacological study defined the thresholds for HIV protection in men who have sex with men (MSM), which are the keys to PrEP promotion and development of new PrEP agents. For African women at risk for HIV and belonging to a priority group considered due to disproportionately high incident HIV infections, the variable adherence in PrEP clinical trials and the limited pharmacologic data have resulted in a lack of clarity about the PrEP adherence required for HIV protection. We propose a study to quantify the adherence-concentration-efficacy thresholds of TDF/FTC PrEP among African cisgender women to inform decisions about optimal PrEP dosing and adherence for HIV protection.

Methods

We randomized 45 low-risk HIV-uninfected African women, aged 18-30 years old, to directly observe the TDF/FTC PrEP of two, four, or seven doses per week for 8 weeks. A complementary age-matched pregnant women cohort at high risk of HIV, who will receive seven doses per week, was recruited (N = 15) with the primary aim of establishing benchmark concentrations in dried blood spots and peripheral blood mononuclear cells. Plasma, whole blood (WB), urine, hair, vaginal fluid, and vaginal tissue (non-pregnant women only) were archived for future testing. Drug concentrations were measured using methods validated for each biological matrix. Pharmacokinetic models were fitted to drug concentrations to quantify concentration-adherence thresholds. To define the drug concentrations associated with HIV protection, we applied the newly defined thresholds from the primary pharmacologic trial to the subset of women randomized to TDF/FTC or TDF in the Partners PrEP Study with the drug concentration assessed in plasma and WB samples. Multiple imputation was used to construct a data set with drug concentrations at each visit when an HIV test was performed for the entire cohort, replicating the work for MSM.

Discussion

The proposed study generated the first African women-specific TDF-PrEP adherence-concentration-efficacy thresholds essential for guiding the accurate interpretation of TDF/FTC PrEP programs and clinical trials of novel HIV prevention products using TDF/FTC as an active control.

Clinical Trial Registration

ClinicalTrials.gov, identifier (NCT05057858).

Trajectories of Pre-exposure Prophylaxis Adherence Among Commercially Insured Individuals

We used group-based trajectory models to identify 4 distinct trajectory patterns of adherence to preexposure prophylaxis (PrEP) among 20 696 users. Only 44.5% were consistently PrEP adherent, with younger age, being female, or having substance use disorder or depression associated with early discontinuation. Public health efforts are needed to improve PrEP adherence.

The Effect of Disclosure of PrEP Use on Adherence Among African Young Women in an Open-Label PrEP Study: Findings from HPTN 082

To develop effective PrEP adherence interventions, it is important to understand the interplay between disclosure of pre-exposure prophalxis (PrEP) use, social support, and PrEP adherence. We leveraged the HPTN 082 study conducted among 451 adolescent girls and young women (AGYW) (ages 16 to 25 years, 2016 to 2019) in South Africa and Zimbabwe. Among the 349 who had month three disclosure and PrEP adherence data, 60% (n = 206) felt supported by adults, and 89% (n = 309) disclosed PrEP use to at least one person. PrEP disclosure was not associated with increased adherence, measured by intracellular tenofovir-diphosphate concentrations in dried blood spots. Women who reported having supportive adults, and disclosed to their parents, had higher adherence at 6 months with an increase of 177 fmol/punch (95% CI 12 to 343, t = 2.11, p = 0.04). PrEP interventions that help AGYW identify supportive relationships and effectively communicate the benefits of PrEP may improve PrEP adherence.Clinicaltrials.gov ID number: NCT02732730.

Assessing Per-Sex-Act HIV-1 Risk Reduction Among Women Using the Dapivirine Vaginal Ring

BACKGROUND

Confounding introduced by individuals' sexual risk behavior is potentially a significant source of bias in HIV-1 prevention intervention studies. To more completely account for sexual behaviors when assessing the efficacy of the monthly dapivirine ring, a new longer-acting HIV-1 prevention option for women, we estimated per-sex-act risk reduction associated with product use.

METHODS

We conducted a secondary analysis of data from MTN-020/ASPIRE, a phase 3, randomized, placebo-controlled efficacy trial of the dapivirine ring that recruited HIV-uninfected, African women aged 18-45 years. With cumulative sex acts as the time scale, we used multivariable Cox regression with inverse probability of censoring weights to estimate HIV-1 risk reduction associated with a rate of dapivirine release indicative of consistent product use.

RESULTS

Women in the dapivirine ring group (n = 1187) had an estimated incidence rate of 2.3 (95% confidence interval [CI], 1.8-3.1) HIV-1 acquisition events per 10 000 sex acts versus 3.6 (95% CI, 2.9-4.4) per 10 000 acts in the placebo group (n = 1187). Dapivirine release indicative of consistent ring use was associated with a 63% (95% CI, 33%-80%) per-sex-act HIV-1 risk reduction.

CONCLUSIONS

These results support the efficacy of the dapivirine vaginal ring for HIV-1 prevention and help to inform decision-making for women, providers, and policymakers regarding product use.

CLINICAL TRIALS REGISTRATION

NCT01617096.

Belgian 2024 guidance on the use of pre-exposure prophylaxis

OBJECTIVES

We aimed to develop a guidance on the use of pre-exposure prophylaxis (PrEP) for HIV tailored to the Belgian context.

METHODS

Different aspects of PrEP care were judged by an expert group of nine Belgian clinicians, seeking consensus for areas of controversies.

RESULTS

PrEP should be considered in HIV negative patients at high risk of acquiring HIV. Currently, only oral tenofovir/emtricitabine is available in Belgium for PrEP, which can be used daily, or also event-driven in cisgender men and trans women who are not taking exogenous estradiol-based hormones. Personal counselling directed at medication adherence and sexual health should have a central role in PrEP care. At the initial assessment clinicians should give attention to symptoms of an acute HIV infection, the patients' immunization status and renal function. A regular follow-up must be set up to diagnose HIV seroconversion, treat sexually transmitted infections, and manage side effects of PrEP.

CONCLUSION

The Belgian guidance on the use of PrEP provides a point of reference for standard PrEP care in Belgium and will be periodically updated.

Dynamicity of HIV Pre-exposure Prophylaxis Usage Pattern and Association with Executed Adherence in MSM: An Implementation Study in Hong Kong

Pre-exposure prophylaxis (PrEP) use has been shown to be effective for HIV prevention in men who have sex with men (MSM). PrEP use coverage aside, maintenance of high PrEP adherence is crucial in ensuring the achievement of HIV prevention. In this PrEP implementation study in Hong Kong, we examined the patterns of PrEP use in MSM and evaluated their association with prevention-effective adherence for HIV prevention. In January 2020-June 2021 in Hong Kong, 312 recruited MSM (median 30 years old) were followed up for 1 year, with HIV and creatinine testing, consultation, and PrEP refill. No HIV breakthrough infection was observed. As a measure of prevention-effective adherence, executed adherence (EA) was expressed as the proportion of days with HIV risk that were protected by PrEP and/or condom in 6 months. In 65,585 diary entries of 215 MSM, the median proportion of EA achieved was 89% (IQR 84-93%). Three latent classes of PrEP users were identified by latent class analysis. Taking Class 1 "daily dominant PrEP" (n = 113, 53%) as reference, Class 2 "episodic PrEP" (n = 76, 35%) was adopted by MSM with less sexual activity, had less PrEP refill and lower EA level, while Class 3 "mixed PrEP schedule" (n = 26, 12%) MSM were more sexually active but with a similar EA level. The study findings showed varied and dynamic PrEP usage patterns in the real-world setting. Strategies for promoting adherence are needed to ensure the maintenance of high EA level among PrEP-using MSM especially those on episodic PrEP schedule.

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.

HIV Preexposure Prophylaxis With Emtricitabine and Tenofovir Disoproxil Fumarate Among Cisgender Women

Importance

Emtricitabine and tenofovir disoproxil fumarate (F/TDF) for HIV preexposure prophylaxis (PrEP) is highly effective in cisgender men who have sex with men (MSM) when adherence is high (>4 doses/week). Real-world effectiveness and adherence with F/TDF for PrEP in cisgender women is less well characterized.

Objective

To characterize the effectiveness of F/TDF for PrEP and its relationship with adherence in cisgender women.

Design, Setting, and Participants

Data were pooled from 11 F/TDF PrEP postapproval studies conducted in 6 countries that included 6296 cisgender women aged 15 to 69 years conducted from 2012 to 2020. HIV incidence was evaluated according to adherence level measured objectively (tenofovir diphosphate concentration in dried blood spots or tenofovir concentration in plasma; n = 288) and subjectively (electronic pill cap monitoring, pill counts, self-report, and study-reported adherence scale; n = 2954) using group-based trajectory modeling.

Exposures

F/TDF prescribed orally once a day. HIV incidence was analyzed in subgroups based on adherence trajectory.

Main Outcomes and Measures

HIV incidence.

Results

Of the 6296 participants, 46% were from Kenya, 28% were from South Africa, 21% were from India, 2.9% were from Uganda, 1.6% were from Botswana, and 0.8% were from the US. The mean (SD) age at PrEP initiation across all studies was 25 (7) years, with 61% of participants being younger than 25 years. The overall HIV incidence was 0.72 per 100 person-years (95% CI, 0.51-1.01; 32 incident HIV diagnoses among 6296 participants). Four distinct groups of adherence trajectories were identified: consistently daily (7 doses/week), consistently high (4-6 doses/week), high but declining (from a mean of 4-6 doses/week and then declining), and consistently low (less than 2 doses/week). None of the 498 women with consistently daily adherence acquired HIV. Only 1 of the 658 women with consistently high adherence acquired HIV (incidence rate, 0.13/100 person-years [95% CI, 0.02-0.92]). The incidence rate was 0.49 per 100 person-years (95% CI, 0.22-1.08) in the high but declining adherence group (n = 1166) and 1.27 per 100 person-years (95% CI, 0.53-3.04) in the consistently low adherence group (n = 632).

Conclusions and Relevance

In a pooled analysis of 11 postapproval studies of F/TDF for PrEP among cisgender women, overall HIV incidence was 0.72 per 100 person-years; individuals with consistently daily or consistently high adherence (4-6 doses/week) to PrEP experienced very low HIV incidence.

Ex-vivo rectal tissue infection with HIV-1 to assess time to protection following oral preexposure prophylaxis with tenofovir disoproxil/emtricitabine

OBJECTIVES

We wished to assess time to protection from HIV-1 infection following oral tenofovir disoproxil and emtricitabine (TDF/FTC) as preexposure prophylaxis (PrEP), using ex-vivo rectal tissue infections and drug concentration measures in blood and rectal tissue.

DESIGN/METHODS

Participants from the ANRS PREVENIR study (NCT03113123) were offered this sub-study after a 14-day wash-out. We used an ex-vivo model to evaluate rectal tissue HIV-1 susceptibility before and after PrEP, 2 h after two pills or 7 days of a daily pill of TDF/FTC. PrEP efficacy was expressed by the difference (after-before) of 14-day cumulative p24 antigen levels. TFV-DP and FTC-TP levels were measured in rectal tissue and PBMCs and correlated with HIV-1 infection.

RESULTS

Twelve and 11 men were analyzed in the 2 h-double dose and 7 days-single dose groups, respectively. Cumulative p24 differences after-before PrEP were -144 pg/ml/mg (IQR[-259;-108]) for the 2 h-double dose group ( P  = 0.0005) and -179 pg/ml/mg (IQR [-253;-86]) for the 7 days-single dose group ( P  = 0.001), with no differences between groups ( P  = 0.93). Rectal TFV-DP was below quantification after a double dose, but FTC-TP levels were similar to levels at 7 days. There was a significant correlation between rectal FTC-TP levels and p24 changes after a double dose ( R  = -0.84; P  = 0.0001).

CONCLUSION

Oral TDF/FTC provided similar protection against HIV-1 infection of rectal tissue 2 h after a double dose or 7 days of a daily dose. At 2 h, this protection seems driven by high FTC-TP concentrations in rectal tissue. This confirms the importance of combining TDF and FTC to achieve early protection.

Sexual Identity Development and Social Ecological Facilitators and Barriers of PrEP Uptake and Adherence Among Latinx Men Who Have Sex with Men

Latinx gay, bisexual, and other men who have sex with men (LMSM) report lower pre-exposure prophylaxis (PrEP) use than their white, non-Latinx counterparts. We hypothesize that this disparity is partially attributable to social ecological factors that can be addressed via prevention interventions. In this retrospective study, we first examined data from 253 LMSM to determine whether theorized associations existed between acquisition of a PrEP prescription (uptake) in relation to several social ecological factors based on a conceptual framework of determinants of access to and uptake of PrEP for LMSM. We also explored relations between frequency of PrEP use (adherence) and social ecological factors with a subsample of 33 LMSM who had initiated PrEP 12 months prior to assessment. In this study, individual-level factors from this framework included age and socioeconomic status. Perceived access to medical care represented both individual- and community-level determinants of PrEP uptake and adherence. Interpersonal-level factors were social support and relationship status. Structural/cultural-level factors were sexual identity development status, the masculinity norm of heterosexual self-presentation, traditional Latinx masculine gender role beliefs of machismo and caballerismo, racial identity, and immigration status. Results indicated that older men and those who endorsed the synthesis/integration status of sexual identity development were more likely to acquire a PrEP prescription during their lifetime in comparison to peers. PrEP adherence was linked with being older, reporting higher socioeconomic status, reporting more appraisal social support, self-identifying as white-Latinx, being U.S.-born, and endorsing less sexual identity uncertainty and more heterosexual self-presentation. Results specify modifiable factors that may inform tailored, community-based prevention efforts to increase PrEP use and decrease existing HIV/AIDS disparities among LMSM.

Effect of differentiated direct-to-pharmacy PrEP refill visits supported with client HIV self-testing on clinic visit time and early PrEP continuation

INTRODUCTION

Delivery of oral pre-exposure prophylaxis (PrEP) is being scaled up in Africa, but clinic-level barriers including lengthy clinic visits may threaten client continuation on PrEP.

METHODS

Between January 2020 and January 2022, we conducted a quasi-experimental evaluation of differentiated direct-to-pharmacy PrEP refill visits at four public health HIV clinics in Kenya. Two clinics implemented the intervention package, which included direct-to-pharmacy for PrEP refill, client HIV self-testing (HIVST), client navigator, and pharmacist-led rapid risk assessment and dispensing. Two other clinics with comparable size and client volume served as contemporaneous controls with the usual clinic flow. PrEP continuation was evaluated by visit attendance and pharmacy refill records, and time and motion studies were conducted to determine time spent in the clinics. Dried blood spots were collected to test for tenofovir-diphosphate (TFV-DP) at random visits. We used logistic regression to assess the intervention effect on PrEP continuation and the Wilcoxon rank sum test to assess the effect on clinic time.

RESULTS

Overall, 746 clients were enrolled, 366 at control clinics (76 during pre-implementation and 290 during implementation phase), and 380 at direct-to-pharmacy clinics (116 during pre-implementation and 264 during implementation phase). Prior to implementation, the intervention and control clinics were comparable on client characteristics (female: 51% vs. 47%; median age: 33 vs. 33 years) and PrEP continuation (35% vs. 37% at 1 month, and 37% vs. 39% at 3 months). The intervention reduced total time spent at the clinic by 35% (median of 51 minutes at control vs. 33 minutes at intervention clinics; p<0.001), while time spent on HIV testing (20 vs. 20 minutes; p = 0.50) and pharmacy (8 vs. 8 minutes; p = 0.8) was unchanged. PrEP continuation was higher at intervention versus the control clinics: 45% versus 33% at month 1, 34% versus 25% at month 3 and 23% versus 16% at month 6. TFV-DP was detected in 85% (61/72) of samples, similar by the study group (83% vs. 85%).

CONCLUSIONS

A client-centred PrEP delivery approach with direct-to-pharmacy PrEP refill visits plus client HIVST significantly reduced clinic visit time by more than one-third and improved PrEP continuation in public health HIV clinics in Kenya.

Questioning risk compensation: pre-exposure prophylaxis (PrEP) and sexually transmitted infections among men who have sex with men, capital region of Denmark, 2019 to 2022

BackgroundPre-exposure prophylaxis (PrEP) effectively prevents HIV, but its association with sexually transmitted infections (STIs) has raised concerns about risk compensation, potentially impacting the expansion of PrEP programmes.AimWe examined the relationship between PrEP and the incidence of chlamydia, gonorrhoea and syphilis.MethodsIn this prospective cohort study, we compared STI rates before and after PrEP initiation among users in the capital region of Denmark (2019-2022), calculating incidence rate ratios adjusted for age and testing frequency (aIRR). To pinpoint when increases began, we plotted weekly STI rates, adjusting the timeline to correspond with PrEP initiation.ResultsThe study included 1,326 PrEP users with a median age of 35 years. The STI incidence rate per 100,000 person-years rose from 35.3 before to 81.2 after PrEP start, with an aIRR of 1.35 (95% CI: 1.18-1.56). Notably, this increase preceded PrEP initiation by 10-20 weeks. Specific aIRR for chlamydia, gonorrhoea and syphilis were 1.23 (95% CI: 1.03-1.48), 1.24 (95% CI: 1.04-1.47) and 1.15 (95% CI: 0.76-1.72), respectively. In subanalyses for anatomical sites aIRR was 1.26 (95% CI: 1.01-1.56) for rectal chlamydia and 0.66 (95% CI: 0.45-0.96) for genital gonorrhoea.ConclusionWe found a 35% increase in STI incidence associated with PrEP use. It started before PrEP initiation, challenging the assumption that PrEP leads to risk compensation. Instead, the data suggest that individuals seek PrEP during periods of heightened sexual risk-taking. Consequently, PrEP programmes should include sexual health consultations, STI testing, treatment and prevention strategies to prevent HIV and improve sexual health.

Estimating the costs and perceived benefits of oral pre-exposure prophylaxis (PrEP) delivery in ten counties of Kenya: a costing and a contingent valuation study

Background

Kenya included oral PrEP in the national guidelines as part of combination HIV prevention, and subsequently began providing PrEP to individuals who are at elevated risk of HIV infection in 2017. However, as scale-up continued, there was a recognized gap in knowledge on the cost of delivering oral PrEP. This gap limited the ability of the Government of Kenya to budget for its PrEP scale-up and to evaluate PrEP relative to other HIV prevention strategies. The following study calculated the actual costs of oral PrEP scale-up as it was being delivered in ten counties in Kenya. This costing also allowed for a comparison of various models of service delivery in different geographic regions from the perspective of service providers in Kenya. In addition, the analysis was also conducted to understand factors that indicate why some individuals place a greater value on PrEP than others, using a contingent valuation technique.

Methods

Data collection was completed between November 2017 and September 2018. Costing data was collected from 44 Kenyan health facilities, consisting of 23 public facilities, 5 private facilities and 16 drop-in centers (DICEs) through a cross-sectional survey in ten counties. Financial and programmatic data were collected from financial and asset records and through interviewer administered questionnaires. The costs associated with PrEP provision were calculated using an ingredients-based costing approach which involved identification and costing of all the economic inputs (both direct and indirect) used in PrEP service delivery. In addition, a contingent valuation study was conducted at the same 44 facilities to understand factors that reveal why some individuals place a greater value on PrEP than others. Interviews were conducted with 2,258 individuals (1,940 current PrEP clients and 318 non-PrEP clients). A contingent valuation method using a "payment card approach" was used to determine the maximum willingness to pay (WTP) of respondents regarding obtaining access to oral PrEP services.

Results

The weighted cost of providing PrEP was $253 per person year, ranging from $217 at health centers to $283 at dispensaries. Drop-in centers (DICEs), which served about two-thirds of the client volume at surveyed facilities, had a unit cost of $276. The unit cost was highest for facilities targeting MSM ($355), while it was lowest for those targeting FSW ($248). The unit cost for facilities targeting AGYW was $323 per person year. The largest percentage of costs were attributable to personnel (58.5%), followed by the cost of drugs, which represented 25% of all costs. The median WTP for PrEP was $2 per month (mean was $4.07 per month). This covers only one-third of the monthly cost of the medication (approximately $6 per month) and less than 10% of the full cost of delivering PrEP ($21 per month). A sizable proportion of current clients (27%) were unwilling to pay anything for PrEP. Certain populations put a higher value on PrEP services, including: FSW and MSM, Muslims, individuals with higher education, persons between the ages of 20 and 35, and households with a higher income and expenditures.

Discussion

This is the most recent and comprehensive study on the cost of PrEP delivery in Kenya. These results will be used in determining resource requirements and for resource mobilization to facilitate sustainable PrEP scale-up in Kenya and beyond. This contingent valuation study does have important implications for Kenya's PrEP program. First, it indicates that some populations are more motivated to adopt oral PrEP, as indicated by their higher WTP for the service. MSM and FSW, for example, placed a higher value on PrEP than AGYW. Higher educated individuals, in turn, put a much higher value on PrEP than those with less education (which may also reflect the higher "ability to pay" among those with more education). This suggests that any attempt to increase demand or improve PrEP continuation should consider these differences in client populations. Cost recovery from existing PrEP clients would have potentially negative consequences for uptake and continuation.

Daily Oral HIV Pre-exposure Prophylaxis Among Young Men Who Have Sex With Men in the United States: Cost-saving at Generic Drug Price

BACKGROUND

Adherence and retention concerns raise questions about the effectiveness and cost-effectiveness of oral HIV pre-exposure prophylaxis (PrEP) in young men who have sex with men (YMSM).

METHODS

Using an adolescent-focused simulation model, we compared annual HIV screening alone with tenofovir disoproxil fumarate/emtricitabine-based oral PrEP with every 3-month HIV screening in YMSM (aged 15-24) at increased risk of HIV. Data derived from published sources included: age-stratified HIV incidence/100 person-years (PY) on- or off-PrEP (0.6-10.1 or 0.4-6.4), PrEP retention at 6 years (28%), transmissions by HIV RNA level (0.0-78.4/100PY) and annual costs of antiretroviral therapy ($32 000-69 000), HIV care ($3100-34 600), and PrEP program/generic drug ($900/360). Outcomes included transmissions (percent of cohort infected), quality-adjusted life-years (QALYs), costs ($), and incremental cost-effectiveness ratios ($/QALY). We explored the sensitivity of findings to variation in HIV incidence and drug prices.

RESULTS

Compared with annual screening alone, PrEP would increase QALYs (9.58 to 9.67), reduce new infections (37% to 30%), and decrease costs (by $5000) over 10 years. PrEP would remain cost-saving for HIV incidence off-PrEP ≥5.1/100PY or annual PrEP price ≤$1200. Over a lifetime horizon, PrEP would be cost-saving for HIV incidence off-PrEP ≥1.0/100PY, across all retention assumptions examined. PrEP would not be cost-effective at HIV incidence ≤0.1/100PY, regardless of drug price, due to programmatic costs.

CONCLUSIONS

In US YMSM at increased risk of HIV, generic oral PrEP and every-3-month screening would be cost-saving compared with annual screening alone, even with high discontinuation and low adherence, over a range of HIV incidences.

Significant Publications on Infectious Diseases Pharmacotherapy in 2021

Purpose: To summarize the most noteworthy infectious diseases (ID) pharmacotherapy articles published in peer-reviewed literature in 2021. Summary: Members of the Houston Infectious Diseases Network (HIDN) nominated articles that were deemed to have significant contributions to ID pharmacotherapy in 2021. These nominations included articles pertaining to both general ID, including coronavirus disease 2019 (COVID-19), and human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS) pharmacotherapy. A total of 35 articles were nominated by HIDN: 30 articles pertaining to general ID pharmacotherapy and 5 articles with HIV/AIDS focus. To select the most influential articles of 2021, a survey was created and distributed to members of the Society of Infectious Diseases Pharmacists (SIDP). Of the 239 SIDP members who responded to the survey, there were 192 recorded votes for the top 10 general ID pharmacotherapy articles and 47 recorded votes for the top HIV/AIDS article, respectively. The top publications are summarized. Conclusion: Antimicrobial stewardship and the optimal management of infectious disease states continues to be a priority in the midst of the ongoing coronavirus disease 2019 (COVID-19) global pandemic. In light of the sheer volume of ID-related articles published in the past year, this review aims to aid clinicians in remaining up-to-date on key practice-changing ID pharmacotherapy publications from 2021.

Gender Affirming Hormones Do Not Affect the Exposure and Efficacy of F/TDF or F/TAF for HIV Preexposure Prophylaxis: A Subgroup Analysis from the DISCOVER Trial

Purpose

Transgender women are disproportionately affected by HIV and are underutilizing preexposure prophylaxis (PrEP). The lower uptake of PrEP by transgender women may be, in part, owing to the perception that taking PrEP may lower the efficacy of gender-affirming hormone therapy (GAHT) or to provider concerns that GAHT may lower the efficacy of PrEP.

Methods

DISCOVER was a randomized, double-blind, noninferiority trial comparing emtricitabine (FTC, F) and tenofovir alafenamide (F/TAF) versus emtricitabine and tenofovir disoproxil fumarate (F/TDF) as PrEP among transgender women and cisgender men who have sex with men (MSM). This nested substudy of the DISCOVER trial compared the exposure of the active intracellular metabolites of FTC and tenofovir (TFV), FTC triphosphate (FTC-TP) and TFV diphosphate (TFV-DP), in peripheral blood mononuclear cells (PBMC) among transgender women receiving GAHT versus MSM within the F/TAF and F/TDF groups.

Results

Our results demonstrate that TFV-DP and FTC-TP levels in PBMC were comparable between transgender women on GAHT and MSM receiving F/TAF, and between transgender women on GAHT and MSM receiving F/TDF. TFV-DP concentrations remained above the EC90 of 40 fmol/106 cells across all groups. No clinically significant drug-drug interactions of GAHT were observed with either F/TAF or F/TDF in this subanalysis.

Conclusions

These findings are consistent with the clinical pharmacology of GAHT, FTC, TDF, and TAF reported in previous studies, and support the continued use of F/TAF and F/TDF for PrEP in transgender women.

Clinicaltrials.gov registration number: NCT02842086.

Attitudes and Intentions toward Use of HIV Pre-Exposure Prophylaxis (PrEP) among Adults Receiving Treatment for Opioid Use

Background: Although pre-exposure prophylaxis (PrEP) prevents HIV, little is known about PrEP awareness and factors associated with intention to take PrEP among people with opioid use disorder (OUD). Methods: HIV-negative adults recruited from an outpatient treatment program in Cincinnati, Ohio completed self-administered surveys. Items derived from literature and health behavioral theory included demographics, sexual and drug use behaviors, HIV prevention practices, PrEP knowledge, and attitudes toward PrEP. Primary outcomes were 1) intention to ask a clinician about PrEP and 2) intention to accept PrEP if recommended by a clinician. Outcomes were dichotomized into higher vs. lower intention for analyses in logistic regression models. Results: Among 198 participants, 60.3% reported past injection drug use. Among 58 participants (29.3%) meeting criteria for PrEP, 24% were aware of PrEP, 15.5% had discussed it with a clinician, and 5% had taken it. Factors associated with intention to ask a clinician about PrEP included being somewhat confident about consistent condom use (p < 0.01), motivation to comply with normative beliefs (p < 0.01), and reporting that PrEP fits very well (p < 0.01) and is easy to fit (p < 0.01) into current prevention practices. Factors associated with intention to accept PrEP if recommended by a clinician included motivation to comply with normative beliefs (p < 0.01) and PrEP being easy to fit into current prevention practices (p < 0.01). Conclusion: Among participants meeting indications for PrEP, only 24% were aware of it and few had taken it. Interventions that normalize PrEP and target incorporating PrEP into current prevention practices may improve uptake among individuals with OUD.

Tenofovir Activation Is Diminished in the Brain and Liver of Creatine Kinase Brain-Type Knockout Mice

Tenofovir (TFV) is a nucleotide reverse transcriptase inhibitor prescribed for the treatment and prevention of human immunodeficiency virus infection and the treatment of chronic hepatitis B virus infection. Here, we demonstrate that creatine kinase brain-type (CKB) can form tenofovir-diphosphate (TFV-DP), the pharmacologically active metabolite, in vitro and identify nine missense mutations (C74S, R96P, S128R, R132H, R172P, R236Q, C283S, R292Q, and H296R) that diminish this activity. Additional characterization of these mutations reveals that five (R96P, R132H, R236Q, C283S, and R292Q) have ATP dephosphorylation catalytic efficiencies less than 20% of those of the wild type (WT), and seven (C74S, R96P, R132H, R172P, R236Q, C283S, and H296P) induce thermal instabilities. To determine the extent CKB contributes to TFV activation in vivo, we generated a CKB knockout mouse strain, Ckbtm1Nnb. Using an in vitro assay, we show that brain lysates of Ckbtm1Nnb male and female mice form 70.5 and 77.4% less TFV-DP than wild-type brain lysates of the same sex, respectively. Additionally, we observe that Ckbtm1Nnb male mice treated with tenofovir disoproxil fumarate for 14 days exhibit a 22.8% reduction in TFV activation in the liver compared to wild-type male mice. Lastly, we utilize mass spectrometry-based proteomics to elucidate the impact of the knockout on the abundance of nucleotide and small molecule kinases in the brain and liver, adding to our understanding of how the loss of CKB may be impacting tenofovir activation in these tissues. Together, our data suggest that disruptions in CKB may lower levels of active drugs in the brain and liver.

Causal Effects of Stochastic PrEP Interventions on HIV Incidence Among Men Who Have Sex With Men

Antiretroviral preexposure prophylaxis (PrEP) is highly effective in preventing human immunodeficiency virus (HIV) infection, but uptake has been limited and inequitable. Although interventions to increase PrEP uptake are being evaluated in clinical trials among men who have sex with men (MSM), those trials cannot evaluate effects on HIV incidence. Estimates from observational studies of the causal effects of PrEP-uptake interventions on HIV incidence can inform decisions about intervention scale-up. We used longitudinal electronic health record data from HIV-negative MSM accessing care at Fenway Health, a community health center in Boston, Massachusetts, from January 2012 through February 2018, with 2 years of follow-up. We considered stochastic interventions that increased the chance of initiating PrEP in several high-priority subgroups. We estimated the effects of these interventions on population-level HIV incidence using a novel inverse-probability weighted estimator of the generalized g-formula, adjusting for baseline and time-varying confounders. Our results suggest that even modest increases in PrEP initiation in high-priority subgroups of MSM could meaningfully reduce HIV incidence in the overall population of MSM. Interventions tailored to Black and Latino MSM should be prioritized to maximize equity and impact.

Real-World Implementation Challenges Associated with a Digital Pill System to Measure Adherence to HIV Pre-Exposure Prophylaxis from Two Studies of Men Who Have Sex With Men

Once-daily oral pre-exposure prophylaxis (PrEP) is highly effective for HIV prevention, but its efficacy is dependent on adherence, which can be challenging for men who have sex with men (MSM) with substance use. Digital pill systems (DPS) represent a novel tool for directly measuring adherence through ingestible radiofrequency sensors that confirm ingestions in real-time. We examined operational challenges across two studies involving DPS to measure PrEP adherence. While most participants successfully operated the system, a number of technological and sociobehavioral challenges requiring intervention were identified across both studies. Technological issues were both system- and participant-related, and were primarily addressed with technical updates and participant re-education, while sociobehavioral issues, including health and housing changes and issues with technology access, warranted innovative solutions. Future research leveraging DPS technology should develop robust supportive infrastructure and mitigation procedures to promptly identify and resolve operational issues to optimize the potential benefits of DPS use.

Psychological and Behavioural Within-participant Predictors of Adherence to Oral HIV Pre-Exposure Prophylaxis (PrEP)

Oral PrEP's effectiveness relies on adequate adherence during periods of substantial HIV risk. Since most PrEP users will miss doses, understanding predictors within participants can help to explain adherence. We used a cross-sectional, within-participant design with 67 gay, bisexual, and other men who have sex with men taking PrEP daily. Using a questionnaire, informed by the Information Motivation Behavioral Skills Model, participants were asked about an adherent and a non-adherent episode. PrEP non-adherence was associated with non-normality of the day (p < .001), being out of the home (p < .001), weekend days (p = .01), having company (p = .02), using substances (p = 0.02), not using reminders (p = .03), lower PrEP information (p = .04), lower behavioural skills (p < .001) and less positive affect (p = .002). PrEP adherence assessment could focus on situational variations, supporting the construction of alternative strategies to facilitate adherence in these situations.

Attitudes Toward and Beliefs in the Effectiveness of Biomedical HIV Prevention Strategies Among Emerging and Young Adult Sexual Minority Men

BACKGROUND

Pre-exposure prophylaxis (PrEP) and HIV treatment as prevention, which underlies the Undetectable = Untransmittable (U = U) campaign, are two effective biomedical approaches for HIV prevention among sexual minority men (SMM). Attitudes toward PrEP and U = U may differ between SMM emerging adults (EA: 18-24 years old) and young adults (YA: 25-29 years old) to drive differences in sexual behavior. However, to date, few studies assessed the degree to which YAs and EAs differ in their beliefs in the effectiveness of PrEP and U = U.

METHOD

A national sample of 80 SMM in the USA (Mage = 25.1 years; 53.7% racial/ethnic minority; 38.8% EA; 61.3% YA) participated in a 6-month mHealth intervention for PrEP adherence. Non-parametric tests assessed differences in sexual behaviors and attitudes toward the effectiveness of PrEP and U = U between EAs and YAs using baseline data.

RESULTS

Compared to EAs, higher proportions of YAs trusted PrEP's effectiveness and considered condom use unnecessary after taking PrEP. More YAs than EAs were willing to engage in sexual behaviors that they felt too risky before learning about U = U and were more comfortable having condomless sex with HIV-positive partners. Conversely, a greater proportion of EAs than YAs preferred to use condoms even when their partners are on anti-HIV medications.

CONCLUSION

Overall, YAs trusted the effectiveness of U = U and PrEP more than EAs, underscoring developmental differences in SMM's perspectives on biomedical HIV prevention tools. Our findings underscore the importance of tailoring messages on biomedical HIV prevention options differently for EAs and YAs to optimize uptake.

Willingness to take long-acting injectable pre-exposure prophylaxis among men who have sex with men who participated in the CROPrEP study: a cross-sectional online study

INTRODUCTION

Evidence on the willingness of men who have sex with men (MSM) with oral pre-exposure prophylaxis (PrEP) experience, especially those with suboptimal adherence, to take long-acting injectable PrEP (LAI-PrEP) is critical to guide future LAI-PrEP implementation.

OBJECTIVE

The objective was to assess the willingness of MSM with oral PrEP experience to take LAI-PrEP.

METHODS

MSM who participated in the China Real-world Study of Oral PrEP (CROPrEP) were enrolled in this study. Information on the willingness of MSM to take LAI-PrEP and potential correlates was collected using a structured online questionnaire. The main outcomes were the willingness of MSM to take LAI-PrEP and its association with HIV-related behaviours, sexually transmitted infections, and oral PrEP history. Logistic regression was used to identify correlates of the willingness of MSM to take LAI-PrEP.

RESULTS

A total of 612 former CROPrEP participants (FCPs) were included in this study. There were 315 (51.5%) daily oral PrEP (D-PrEP) users and 297 (48.5%) event-driven oral PrEP (ED-PrEP) users at the last follow-up. Most FCPs (77.8%) were willing to take free LAI-PrEP. FCPs with no less than two sexual male partners (aOR = 1.54, [95% CI: 1.04, 2.29], P = 0.031), those with male partners with unknown HIV statuses (aOR = 2.04, [95% CI: 1.31, 3.18], P = 0.002), those with recreational drug use (aOR = 1.58, [95% CI: 1.05, 2.40], P = 0.030), and those with HSV-2 positivity (aOR = 2.15, [95% CI: 1.30, 3.57], P = 0.003) were more willing to take LAI-PrEP, while ED-PrEP users (aOR = 0.66, [95% CI: 0.45, 0.98], P = 0.037) and FCPs with suboptimal oral PrEP adherence (aOR = 0.58, [95% CI: 0.36, 0.94], P = 0.026) were less willing to take LAI-PrEP.

CONCLUSION

LAI-PrEP has good prospects for expanding PrEP coverage. However, FCPs with suboptimal oral PrEP adherence are less likely to take LAI-PrEP. Further intervention and implementation efforts are needed to improve the willingness of MSM to use LAI-PrEP, and sexual health should be considered during the discussion about PrEP initiation.

Oral Pre-Exposure Prophylaxis for HIV Discontinuation in a Large Cohort of Adolescent Men Who Have Sex With Men and Transgender Women in Brazil

PURPOSE

This study aimed to describe pre-exposure prophylaxis (PrEP) for HIV discontinuation in adolescent men who have sex with men (aMSM) and adolescent transgender women (aTGW) and to identify factors associated with discontinuation.

METHODS

The PrEP1519 study included a cohort of aMSM and aTGW aged 15-19 years old, and it was conducted in three large Brazilian capital cities. For this analysis, we included adolescents who initiated PrEP. PrEP discontinuation was defined as no possession of PrEP pills for >90 days. Kaplan-Meier curves were used to analyze the probabilities of discontinuation, and survival distributions stratified by covariates were compared using log-rank or Wilcoxon tests. Cox regression models were used to estimate the adjusted hazard ratio (aHR) with a 95% confidence interval (95% CI).

RESULTS

We included 908 adolescents, 829 (91.30%) aMSM and 79 (8.70%) aTGW, most of whom were 18-19 years (80.29%). The incidence rate of discontinuation was 75.6 per 100 person-years. The probability of discontinuation was 52.61% in the first year. The multivariate analysis demonstrated that the aTGW (aHR = 1.63; 95% CI: 1.02-1.64) and adolescents with a medium (aHR = 1.29; 95% CI: 1.02-1.64) or low (aHR = 1.65; 95% CI: 1.29-2.12) perceived risk of HIV infection had an increased risk of discontinuation, whereas the adolescents with a partner living with HIV had a lower risk of discontinuation (aHR = 0.57; 95% CI: 0.35-0.91).

DISCUSSION

Adolescents with a high risk for discontinuation may need additional support that emphasizes the value of PrEP as a tool for HIV prevention because PrEP discontinuation was associated with a disconnect between HIV risk perception and HIV prevention.

The Promise of Pre-Exposure Prophylaxis - Examining Awareness, Knowledge, and Willingness to use Different Modalities Among US-Based African Immigrants

This study aims to describe and understand the relationship between sociodemographic factors and PrEP awareness, and willingness to use a PrEP modality (oral or injectable).Despite the availability of effective prevention tools such as HIV preexposure prophylaxis (PrEP), African immigrants in the United States are disproportionately affected by HIV. Although PrEP can significantly reduce HIV infection in this population, research evidence on PrEP outcomes, such as awareness, knowledge, and willingness to use, is extremely limited. Between April and May 2022, 92 participants completed an online survey assessing their awareness, knowledge, and willingness to use oral or injectable PrEP. The association between sociodemographic characteristics and PrEP-related measures was examined using descriptive and Pearson's chi-squared or Fisher's exact tests. Participants (N = 92) were born between 1990 and 1999 (46.7%), female (70.76%) and highly educated (59.6%). About 52.2% were unaware of PrEP, and 65.6% were willing to use a PrEP modality. Findings indicate that individuals who reported being aware of PrEP demonstrated a high level of knowledge regarding the medication. Having a healthcare provider was associated with PrEP awareness and willingness to use, while educational status was associated with PrEP awareness. 51.1% of participants were willing to use an oral pill for prevention and 47.8% were willing to use injectable PrEP. Our findings highlight the need for PrEP-related research and interventions for African immigrants to increase awareness and provide options for HIV prevention, as African immigrants are currently not well-represented in PrEP delivery systems in the US.

Barriers and facilitators to scaling up access to HIV pre-exposure prophylaxis among key populations: A qualitative study of the incentive-based PrEP Seguro program in Mexico

Introduction

Daily oral pre-exposure prophylaxis (PrEP) is highly safe and effective for HIV prevention, yet barriers to PrEP access and adherence persist among key populations. In Mexico, incentive-based pilot programs have been effective in improving PrEP adherence among male sex workers. Understanding the experiences of providers and program implementers is critical to integrating PrEP adherence programs as part of standard care in Mexico and similar settings.

Methods

We conducted 17 in-depth informational interviews with care providers and staff responsible for administering PrEP to key populations (men who have sex with men, male sex workers, transgender women) in Mexico City. Interviews explored successes and challenges surrounding current PrEP implementation, as well as adaptations that could facilitate national scale-up of PrEP programs in Mexico. Informant transcripts were analyzed using a hybrid inductive-deductive thematic analysis approach utilizing CFIR constructs for the initial codebook while allowing for inductive findings.

Results

Three key themes emerged from informant interviews as important for promoting PrEP programs in Mexico: 1) increasing individual PrEP access, 2) strengthening quality of care, and 3) improving organizational and structural support.

Conclusions

PrEP in Mexico is currently only available in a few clinics with high patient populations, and siloed HIV services, stigma, and a lack of inter-organizational collaboration remain persistent barriers to PrEP uptake. Promoting government collaboration and increasing financial support for community-based organizations is needed to expand PrEP access. Tailored, destigmatizing information about PrEP services needs to be diffused among both staff and patients to strengthen care quality.

A multicompartment population PK model to predict tenofovir and emtricitabine mucosal tissue concentrations for HIV prevention

A priori use of mathematical modeling and simulation to predict outcomes from incomplete adherence or reduced frequency dosing strategies may mitigate the risk of clinical trial failure with HIV pre-exposure prophylaxis regimens. We developed a semi-physiologic population pharmacokinetic model for two antiretrovirals and their active intracellular metabolites in three mucosal tissues using pharmacokinetic data from a phase I, dose-ranging study. Healthy female volunteers were given a single oral dose of tenofovir disoproxil fumarate (150, 300, or 600 mg) or emtricitabine (100, 200, or 400 mg). Simultaneous co-modeling of all data was performed on a Linux cluster. A 16 compartment, bolus input, linear kinetic model best described the data, containing 986 observations in 23 individuals across three matrices and four analytes. Combined with a defined efficacious concentration target in mucosal tissues, this model can be used to optimize the dose and dosing frequency through Monte-Carlo simulations.

Urine point-of-care tenofovir test demonstrates strong predictive clinical and research utility

BACKGROUND

Preexposure prophylaxis (PrEP) significantly reduces HIV infection risk but is dependent on adherence. Available approaches to measuring adherence have limitations related to accuracy, cost, practicality, and timeliness. This study compared the performance of two methods implementable in clinics and research studies [interview and urine point of care (POC) assay] to the gold-standard for measuring recent and longer term adherence in dried blood spots (DBS).

METHODS

Participants were recruited from RADAR, a cohort study of young MSM, or via online advertisements. At 3 monthly visits, an interviewer administered 7-day timeline follow-back (TLFB) questionnaire, DBS samples were tested for tenofovir-diphosphate (TFV-DP) to estimate average dosing over the prior month and emtricitabine-triphosphate (FTC-TP) to assess recent dosing (past 2-3 days), and a urine POC TFV test to qualitatively assess recent adherence (past 4 days).

RESULTS

Eighty-three PrEP users contributed 163 observations. At visit 1, self-reported adherence was 86% (4+ doses in last 7 days), versus urine TFV (74%), DBS FTC-TP (76%), and DBS TFV-DP (69%). The objective measures of short-term adherence performed similarly well in predicting longer term adherence. In multivariable logistic regression analyses, the urine assay was a significant predictor of DBS TFV-DP (adjusted OR = 19.4, P  < 0.0001); self-report did not add significantly.

CONCLUSION

The urine POC TFV assay had excellent predictive values for adherence and self-report did not add significantly to prediction. The POC assay provides results in several minutes to enable same-visit counseling, requires no specialized training, and is projected to be low-cost.

Efficacy and Safety of Pre-Exposure Prophylaxis to Control HIV and Sexually Transmitted Infection Among Men Who Have Sex With Men: Protocol for a Single-Arm Interventional Study

BACKGROUND

Pre-exposure prophylaxis (PrEP) against HIV infection is a new approach that involves the prophylactic use of the anti-HIV drug Truvada (tenofovir disoproxil fumarate [TDF] and emtricitabine [FTC]) by people not infected with HIV.

OBJECTIVE

The objective of this investigator-initiated clinical study of PrEP was to evaluate the incidence of HIV and sexually transmitted infection (STI), safety and efficacy of PrEP in PrEP users, and their compliance with PrEP medication. The social, medical, and economic benefits of PrEP in Japan was assessed.

METHODS

This single-center feasibility study of PrEP was conducted at the National Center for Global Health and Medicine, Tokyo, Japan, where a cohort of men who have sex with men without HIV was established in January 2017. This single-arm interventional study compared the efficacy and safety of PrEP in a single group of men who have sex with men who participated in PrEP cohort studies. For reference, the cohort study participants who did not participate in the PrEP study were included for comparison. Blood samples were collected for storage at baseline and clinic visits at 1, 3, and 6 months after starting PrEP and every 3 months thereafter. The participants were administered with 1 tablet of Truvada once daily as PrEP. They underwent blood and anal swab tests 1 and 3 months after starting PrEP and then HIV and STI infection assessments at 3-month intervals. Blood samples were centrifuged at the AIDS Clinical Center Laboratory. PrEP safety was evaluated by monitoring serum creatinine levels for symptoms of renal function disorders. The primary end point was the incidence of HIV in PrEP users (100 person-years). The secondary end points were the incidence of STI in PrEP users (100 person-years), incidence of adverse events caused by Truvada, frequency of high-risk sexual activity, and adherence to periodic visits and medication.

RESULTS

The study protocol was reviewed and approved by the certified review board of the National Center for Global Health and Medicine (NCGM-C-003129-03) on April 20, 2020. Changes to the study plan were submitted for review by the certified review board and approved before implementation. Recruitment was completed on March 28, 2019, and the study was completed (last adult participant and last time point) on March 31, 2021. The data were analyzed, and the main results of the study have been published in a peer-reviewed journal.

CONCLUSIONS

The findings indicated that PrEP is a highly effective and feasible strategy against HIV infection in terms of prophylactic response, retention, and compliance.

TRIAL REGISTRATION

UMIN Clinical Trials Registry UMIN000031040; https://tinyurl.com/3msdkeb8 and Japan Registry of Clinical Trials jRCTs031180134; https://tinyurl.com/2p88mhyr.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

RR1-10.2196/50919.

Factors associated with retention on pre-exposure prophylaxis among female sex workers in Kigali, Rwanda

Pre-Exposure Prophylaxis (PrEP) is recommended as an additional HIV prevention measure for persons at substantial risk of HIV acquisition. Although uptake of PrEP among female sex workers (FSW) has increased, retention remains low, resulting in suboptimal benefits. This study aimed at determining PrEP retention rates and associated factors among FSW in Kigali, Rwanda. We retrospectively studied records of 309 FSW abstracted from five (5) health centers for the period between April-June 2020 and April-June 2021. PrEP retention was defined as presenting for a scheduled follow-up visit. We used Kaplan-Meier survival analysis to estimate survival probabilities at months 1,3,6,9, and 12 post-PrEP initiation and Cox regression to determine factors associated with 12-month PrEP retention. Data was analyzed using STATA (version 14.0). Out of 309 FSW whose records were reviewed, data for 268 (87%) were complete. One half (50%, n = 133) of the respondents were aged 25-34 years; slightly more than half (52%, n = 136) were single; nearly three-quarters (73%, n = 196) had completed primary school; majority (88%, n = 236) lived alone; while 69% (n = 184) had no formal employment besides sex work. PrEP dropout rates were 228, 65, 29, 49, and 36 per 100-persons years at months 1, 3, 6, 9 and 12 respectively, with 81%, 72%, 67%, 59% and 53% of FSW that started PrEP retained at these time periods. Multivariable Cox regression revealed that compared to FSW opposed to additional children, the desire to have two or more children (adjusted Hazard Ratio [aHR] = 1.654; 95% Confidential Interval [95%CI]: 1.008, 2.713); and using hormonal (aHR = 2.091, 95%CI: 1.181, 3.702) or no method of contraception other than condoms (aHR = 2.036, 95%CI: 1.006, 4.119) were factors positively associated with PrEP retention. Conversely, compared to consistent condom-use, not using (aHR = 0.329; 95%CI: 0.149, 0.726) or inconsistently using condoms (aHR = 0.413; 95%CI: 0.228, 0.749), and accessing PrEP from ultra-urban clinics (aHR = 0.290; 95%CI: 0.183, 0.458) compared to clinics in the outskirts of the city, were factors negatively associated with PrEP retention. The study found a continuous decline in PrEP retention among FSW with slightly more than half retained at 12 months. To improve outcomes, PrEP retention monitoring should target FSW enrolled in ultra-urban clinics and those not or inconsistently using condoms.

Peer PrEP referral + HIV self-test delivery for PrEP initiation among young Kenyan women: study protocol for a hybrid cluster-randomized controlled trial

BACKGROUND

Oral HIV pre-exposure prophylaxis (PrEP) for HIV prevention is highly effective, but uptake remains low in Africa, especially among young women who are a priority population for HIV prevention services. HIV self-testing (HIVST) has been proven to increase HIV testing in diverse populations but has been underutilized to support linkage to HIV prevention services. Most young women who initiate PrEP in Africa do so through informal peer referral. We wanted to test a model of formalized peer referral enhanced with HIVST delivery among young Kenyan women.

METHODS

The Peer PrEP Trial is a two-arm hybrid effectiveness-implementation cluster-randomized controlled trial being conducted in central Kenya. Eligible participants (i.e., peer providers, n = 80) are women (≥ 16-24 years) refilling or initiating PrEP at public healthcare clinics who can identify at least four peers who could benefit from PrEP and not enrolled in another HIV study. Peer providers will be 1:1 randomized to (1) formal peer PrEP referral + HIVST delivery, where they will be encouraged to refer four peers (i.e., peer clients, ≥ 16-24 years) using educational materials and HIVST kits (two per peer client), or (2) informal peer PrEP referral, where they are encouraged to refer four peer clients using informal word-of-mouth referral. In both arms, peer providers will deliver a standard PrEP referral card with information on nearby public clinics delivering PrEP services. Peer providers will complete surveys at baseline and 3 months; peer clients will complete surveys at 3 months. Our primary outcome is PrEP initiation among peer clients, as reported by peer providers at 3 months. Secondary outcomes include PrEP continuation (any refilling), HIV testing (past 3 months), sexual behaviors (past month), and PrEP adherence (past month) among peer clients, as reported by both peer providers and clients at 3 months. Implementation outcomes will include participants' perceived acceptability, appropriateness, and feasibility of the intervention as well assessments of the intervention's fidelity and cost.

DISCUSSION

Evidence from this trial will help us understand how HIVST could support health systems by facilitating linkage to PrEP services among young women who could benefit in Kenya and similar settings.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04982250. Registered on July 29, 2021.

Efficacy, safety, tolerability, and pharmacokinetics of long-acting injectable cabotegravir for HIV pre-exposure prophylaxis in transgender women: a secondary analysis of the HPTN 083 trial

BACKGROUND

The HIV Prevention Trials Network (HPTN) 083 trial showed that long-acting injectable cabotegravir was more effective than tenofovir disoproxil fumarate plus emtricitabine in preventing HIV in cisgender men and transgender women who have sex with men. We aimed to characterise the cohort of transgender women included in HPTN 083.

METHODS

HPTN 083 is an ongoing, phase 2b/3, randomised, multicentre, double-blind, double-dummy clinical trial done at 43 sites in seven countries (Argentina, Brazil, Peru, the USA, South Africa, Thailand, and Viet Nam). HIV-negative participants were randomly assigned (1:1) to receive injectable cabotegravir or tenofovir disoproxil fumarate plus emtricitabine. The study design and primary outcomes of the blinded phase of HPTN 083 have already been reported. An enrolment minimum of 10% transgender women was set for the trial. Here we characterise the cohort of transgender women enrolled from Dec 6, 2016, to May 14, 2020, when the study was unblinded. We report sociodemographic characteristics, use of gender affirming hormone therapy, and behavioural assessments of the transgender women participants. Laboratory testing and safety evaluations are also reported. The trial is registered at ClinicalTrials.gov, NCT02720094.

FINDINGS

HPTN 083 enrolled 570 transgender women (304 tenofovir disoproxil fumarate plus emtricitabine; 266 injectable cabotegravir). Transgender women were primarily from Asia (225 [39%]) and Latin America (205 [36%]); 330 (58%) reported using gender affirming hormone therapy. Intimate partner violence was common (270 [47%] reported emotional abuse and 172 [30%] reported physical abuse) and 323 (57%) reported a history of childhood sexual abuse. 159 (28%) transgender women disagreed that they were at risk for HIV, and 142 (25%) screened positive for depressive symptoms. During study follow-up, incidence of syphilis was 16·25% (95% CI 13·28-19·69), rectal gonorrhoea was 11·66% (9·14-14·66), and chlamydia was 20·61% (17·20-24·49). Frequency of adverse events was similar between the treatment groups. Nine seroconversions occurred among transgender women during the blinded phase of the study (seven in the tenofovir disoproxil fumarate plus emtricitabine group and two in the injectable cabotegravir group); overall incidence was 1·19 per 100 person-years (95% CI 0·54-2·25): 1·80 per 100 person-years (0·73-3·72) in the tenofovir disoproxil fumarate plus emtricitabine group and 0·54 per 100 person-years (0·07-1·95) in the injectable cabotegravir group (hazard ratio 0·34 [95% CI 0·08-1·56]). Cabotegravir concentrations did not differ by gender affirming hormone therapy use.

INTERPRETATION

HIV prevention strategies for transgender women cannot be addressed separately from social and structural vulnerabilities. Transgender women were well represented in HPTN 083 and should continue to be prioritised in HIV prevention studies. Our results suggest that injectable cabotegravir is a safe and effective pre-exposure prophylaxis option for transgender women.

FUNDING

National Institute of Allergy and Infectious Diseases and ViiV Healthcare.

The Use of Daily and On-Demand Oral Pre-Exposure Prophylaxis Dosing Strategies Among Young Adult Gay, Bisexual and Other Men who have Sex with Men Enrolled in an mHealth Adherence Intervention

Pre-exposure prophylaxis (PrEP) is a highly effective HIV prevention option for gay, bisexual and other men who have sex with men (GBMSM). However, with newer PrEP options, a greater understanding of whether and why GBMSM switch dosing strategies is needed to inform clinical practice and research. We assessed the dosing strategies (daily or on-demand) of GBMSM enrolled in an mHealth PrEP adherence pilot intervention at four timepoints over approximately 10 months. Among GBMSM with complete data (n = 66), a consistent daily dosing strategy was used by most (73%) participants across all time points, while on-demand PrEP was used at least once during the study period by 27% of participants. A higher percentage of on-demand PrEP users self-reported as Asian/Pacific Islander and had less positive attitudes toward PrEP, adjusting for key sociodemographic variables and intervention arm. Daily PrEP users reported high numbers of sexual partners, and the primary reason that they would switch to on-demand PrEP is reduced sexual activity. At the final assessment, 75% of participants were taking daily PrEP, of whom 27% reported that they would like to switch to another option, including on-demand and long-acting injectable PrEP. While findings were largely descriptive, they showed that switches in PrEP dosing strategies are relatively common and PrEP strategy choice may vary across racial and ethnic groups.

PrEP retention predictors among key populations in urban areas of Zimbabwe - a machine learning approach

Pre-exposure prophylaxis (PrEP) success depends on adherence and hence retention in care. It is vital to find factors that affect PrEP retention to make this HIV-prevention method successful. The main objectives of this study were to identify the major determinants of PrEP retention at six months from day of initiation and to determine PrEP retention clusters. Data of people who were initiated on PrEP care at Population Services International sites between 2017 and 2019 in Zimbabwe were used. Determinants of PrEP retention were identified using multivariable logistic regression and partitioning around medoids (PAM) cluster analysis to determine the number and composition of PrEP retention clusters. Significant PrEP retention determinants were found to be population type, sex, marital status, employment type, age and education level. Female sex workers were most likely to stay on PrEP compared to other users. We found that PrEP users could be grouped into three risk clusters: cluster 1 consisted of married adult males who are high-risk individuals; cluster 2 consisted of the young single men who have sex with men (MSM); and cluster 3 consisted of adult women who are separated or divorced and employed as sex workers. The retention rates were 32%, 24% and 44% for clusters 1 to 3 respectively. We conclude that adults, female sex workers, high-risk individuals, women, people without or with little education and sex workers stay on PrEP better than youths, MSM, men and educated and employed individuals.