Pre-exposure Prophylaxis Group Research Articles

Investigating the effects of cytokine biomarkers on HIV incidence: a case study for individuals randomized to pre-exposure prophylaxis vs. control.

Understanding and identifying the immunological markers and clinical information linked with HIV acquisition is crucial for effectively implementing Pre-Exposure Prophylaxis (PrEP) to prevent HIV acquisition. Prior analysis on HIV incidence outcomes have predominantly employed proportional hazards (PH) models, adjusting solely for baseline covariates. Therefore, models that integrate cytokine biomarkers, particularly as time-varying covariates, are sorely needed. We built a simple model using the Cox PH to investigate the impact of specific cytokine profiles in predicting the overall HIV incidence. Further, Kaplan-Meier curves were used to compare HIV incidence rates between the treatment and placebo groups while assessing the overall treatment effectiveness. Utilizing stepwise regression, we developed a series of Cox PH models to analyze 48 longitudinally measured cytokine profiles. We considered three kinds of effects in the cytokine profile measurements: average, difference, and time-dependent covariate. These effects were combined with baseline covariates to explore their influence on predictors of HIV incidence. Comparing the predictive performance of the Cox PH models developed using the AIC metric, model 4 (Cox PH model with time-dependent cytokine) outperformed the others. The results indicated that the cytokines, interleukin (IL-2, IL-3, IL-5, IL-10, IL-16, IL-12P70, and IL-17 alpha), stem cell factor (SCF), beta nerve growth factor (B-NGF), tumor necrosis factor alpha (TNF-A), interferon (IFN) alpha-2, serum stem cell growth factor (SCG)-beta, platelet-derived growth factor (PDGF)-BB, granulocyte macrophage colony-stimulating factor (GM-CSF), tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), and cutaneous T-cell-attracting chemokine (CTACK) were significantly associated with HIV incidence. Baseline predictors significantly associated with HIV incidence when considering cytokine effects included: age of oldest sex partner, age at enrollment, salary, years with a stable partner, sex partner having any other sex partner, husband's income, other income source, age at debut, years lived in Durban, and sex in the last 30 days. Overall, the inclusion of cytokine effects enhanced the predictive performance of the models, and the PrEP group exhibited reduced HIV incidences compared to the placebo group.

Perceptions and experiences of daily and long-acting pre-exposure prophylaxis (PrEP) among MSM in India.

Oral pre-exposure prophylaxis (PrEP) is an effective HIV prevention strategy with high efficacy. An increased willingness to use PrEP among at-risk Indian men who have sex with men (MSM) population has been reported; however, little is known about their real experiences that guide their key motivators, facilitators, and barriers with using oral and Long-Acting (LA) Injectable PrEP. We recruited participants (n = 18) through active MSM social media networks. The interviews were conducted using teleconferencing software. Interview topics included participants' sources of knowledge, experiences accessing daily PrEP, safe-sex behaviors while on PrEP, barriers and facilitators around PrEP, long-term goals with PrEP, perceptions around LA PrEP, and discussion around decision-making to switch from oral PrEP to LA PrEP. Transcripts were coded according to interview topics, and key themes were analyzed using a topical data analysis approach. Participants (median age 28 years, ranging from 18 to 40) reported a high perceived risk of HIV. This increased perceived risk was a key motivator for oral PrEP uptake. Most participants shared that they accessed PrEP through non-profit organizations serving the MSM community, where doctor consultations and medication were either free or subsidized. Even when participants reported high adherence to oral PrEP, they expressed discontent with the requirement to take it daily. High condom usage was reported concomitantly with PrEP use among most participants, except for a few who preferred bareback sex. Participants shared that they would prefer to continue PrEP until they are in a monogamous, exclusive relationship. The cost and affordability remained recurring themes, and while participants could afford oral PrEP, they wished it was cheaper, making it more accessible to the community at large. Most participants did not have prior knowledge of LA injectable PrEP but welcomed the intervention, alluding to cost and availability as the key decision-making factors affecting switching. MSM from India we interviewed adopted oral PrEP as an additional HIV prevention strategy to condoms through non-profit and private channels. Cost and broader access remains a concern among the MSM community. More acceptability research about long-acting PrEP is needed among MSM in the Indian context, and it is recommended for government interventions to include oral PrEP groups at higher risk of HIV acquisition.

Efficacy and safety of long-acting cabotegravir compared with daily oral tenofovir disoproxil fumarate plus emtricitabine to prevent HIV infection in cisgender men and transgender women who have sex with men 1 year after study unblinding: a secondary analysis of the phase 2b and 3 HPTN 083 randomised controlled trial

Injectable cabotegravir was superior to daily oral tenofovir disoproxil fumarate plus emtricitabine for HIV prevention in two clinical trials. Both trials had the primary aim of establishing the HIV prevention efficacy of long-acting injectable cabotegravir pre-exposure prophylaxis (PrEP) compared with tenofovir disoproxil fumarate plus emtricitabine daily oral PrEP. Long-acting PrEP was associated with diagnostic delays and integrase strand-transfer inhibitor (INSTI) resistance. This report presents findings from the first unblinded year of the HIV Prevention Trials Network (HPTN) 083 study. The HPTN 083 randomised controlled trial enrolled HIV-uninfected cisgender men and transgender women at elevated HIV risk who have sex with men, from 43 clinical research sites in Africa, Asia, Latin America, and the USA. Inclusion criteria included: a negative HIV serological test at the screening and study entry, undetectable HIV RNA levels within 14 days of study entry, age 18 years or older, overall good health as determined by clinical and laboratory evaluations, and a creatinine clearance of 60 mL/min or higher. Participants were randomly allocated to receive long-acting injectable cabotegravir or daily oral tenofovir disoproxil fumarate plus emtricitabine PrEP. After study unblinding, participants remained on their original regimen awaiting an extension study. HIV infections were characterised retrospectively at a central laboratory. Here we report the secondary analysis of efficacy and safety for the first unblinded year. The primary outcome was incident HIV infection. Efficacy analyses were done on the modified intention-to-treat population using a Cox regression model. Adverse events were compared across treatment groups and time periods (blinded vs unblinded). This trial is registered with ClinicalTrials.gov, NCT02720094. Of the 4488 participants who contributed person-time to the blinded analysis, 3290 contributed person-time to the first unblinded year analysis between May 15, 2020, and May 14, 2021. Updated HIV incidence in the blinded phase was 0·41 per 100 person-years for long-acting injectable cabotegravir PrEP and 1·29 per 100 person-years for daily oral tenofovir disoproxil fumarate plus emtricitabine PrEP (hazard ratio [HR] 0·31 [95% CI 0·17-0·58], p=0·0003). HIV incidence in the first unblinded year was 0·82 per 100 person-years for long-acting PrEP and 2·27 per 100 person-years for daily oral PrEP (HR 0·35 [0·18-0·69], p=0·002). Adherence to both study products decreased after study unblinding. Additional infections in the long-acting PrEP group included two with on-time injections; three with one or more delayed injections; two detected with long-acting PrEP reinitiation; and 11 more than 6 months after their last injection. Infection within 6 months of cabotegravir exposure was associated with diagnostic delays and INSTI resistance. Adverse events were generally consistent with previous reports; incident hypertension in the long-acting PrEP group requires further investigation. Long-acting injectable cabotegravir PrEP retained high efficacy for HIV prevention in men and transgender women who have sex with men during the first year of open-label follow-up, with a near-identical HR for HIV risk reduction between long-acting injectable cabotegravir and daily oral tenofovir disoproxil fumarate plus emtricitabine PrEP during the first year after unblinding compared with the blinded period. Extended follow-up further defined the risk period for diagnostic delays and emergence of INSTI resistance. Division of AIDS at the National Institute of Allergy and Infectious Diseases, ViiV Healthcare, and Gilead Sciences.

A single-center review of pre-exposure prophylaxis with tixagevimab-cilgavimab in solid organ transplant recipients.

Coronavirus disease 2019 (COVID-19) continues to negatively impact solid organ transplant recipients (SOTr). Data on the use of tixagevimab-cilgavimab (tix-cil) in vaccinated SOTr during circulation of Omicron and its subvariants are limited. Therefore, this single-center review was conducted to evaluate tix-cil efficacy in multiple organ transplant groups during a study period where Omicron B.1.1.529, BA.2.12.1, and BA.5 predominated. In this single-center retrospective study, we evaluated the incidence of COVID-19 infection in adult SOTr who did or did not receive pre-exposure prophylaxis (PrEP) with tix-cil. SOTr were included if they were at least 18 years of age and met emergency use authorization criteria for tix-cil use. The primary outcome analyzed was the incidence of COVID-19 infection. Ninety SOTr met inclusion criteria and comprised of two groups, tix-cil PrEP (n = 45) and no tix-cil PrEP (n = 45). Of SOTr who received tix-cil PrEP, three (6.7%) developed COVID-19 infection, compared to eight (17.8%) in the no tix-cil PrEP group (p = .20). Of the 11 SOTr diagnosed with COVID-19, 15 (82.2%) were fully vaccinated against COVID-19 prior to transplantation. Moreover, 18.2% and 81.8% of the COVID-19 cases observed were asymptomatic and mild-to-moderate, respectively. Our study results, which included months when BA.5 was in increased circulation, suggest no significant difference in COVID-19 infection with or without use of tix-cil PrEP in our solid organ transplant groups. As the COVID-19pandemic continues to evolve, clinical utility of tix-cilshould beevaluatedagainst new, emerging strains.

Pre-Exposure Prophylaxis, Anxiety, Depression and Sexual SatisfactionAmong Men Who Have Sex With Men

Pre-exposure prophylaxis (PrEP) has been implemented as a prevention against HIV; however, its impact on mental health, sexual and life satisfaction has not been addressed. We assessed 114 HIV-negative participants from Spain with ages ranging from 19 to 58 years; 60.5% were PrEP users ( n = 69) and 39.5% were non-users ( n = 45). They completed five questionnaires about life and sexual satisfaction, depression and anxiety. We performed correlations and multiple regression analyses. The PrEP group showed a statistically significant relationship between better sexual satisfaction, and greater life satisfaction. The PrEP group also showed a statistically significant negative relationship with depression and anxiety which was not found in PrEP non-users. Moreover, we found that younger PrEP users had higher scores in anxiety and lower scores in depression than older users. The hierarchical regression analyses also showed that number of sexual partners was a major predictor in the PrEP group for NSSS. The indirect correlation between sexual satisfaction, depression, and anxiety in the PrEP group could underly the benefits of PrEP for patients' sex lives such as increased sexual liberties due to lower anxiety and mental comfort when experiencing chemsex.

Pregnancy and neonatal safety outcomes of timing of initiation of daily oral tenofovir disoproxil fumarate and emtricitabine pre-exposure prophylaxis for HIV prevention (CAP016): an open-label, randomised, non-inferiority trial

The safety of tenofovir disoproxil fumarate and emtricitabine as pre-exposure prophylaxis (PrEP) in pregnant women not living with HIV is uncertain. We aimed to compare pregnancy and neonatal outcomes in women exposed and not exposed to PrEP during pregnancy. In this single-site, open-label, randomised, non-inferiority trial in Durban, South Africa, we evaluated pregnancy and neonatal outcomes in pregnant women aged 18 years or older, not living with HIV, and at 14-28 weeks' gestation at the time of enrolment. Eligible participants were randomly assigned (1:1) using a computer-generated permuted block (block size of ten) randomisation list to immediate initiation or deferred initiation of PrEP until breastfeeding cessation. Participants in the immediate PrEP group received a monthly supply of once daily oral tenofovir disoproxil fumarate 300 mg and emtricitabine 200 mg. Participants in the deferred PrEP group received standard of care for HIV prevention. The primary outcomes were the occurrence of preterm live birth (<37 weeks gestational age) and very preterm birth (<34 weeks gestational age) determined by menstrual dating, low birthweight (<2500 g), very low birthweight (<1500 g), stillbirth (≥20 weeks gestational age), and small for gestational age (birthweight less than the tenth percentile). Post-natal safety outcomes will be reported elsewhere. We used binomial regression models to estimate risk differences and two-sided 90% CIs. Immediate PrEP was non-inferior to deferred PrEP if the upper bound of the 90% CI of the risk difference was less than the upper predefined non-inferiority margin for preterm birth (7·5%), very preterm birth (2·6%), low birthweight (5·5%), very low birthweight (1·2%), stillbirth (1·0%), and small for gestational age (3·7%). All outcomes were analysed in the intention-to-treat population. This study is registered with ClinicalTrials.gov, NCT3227731. Between Sept 25, 2017, and Dec 6, 2019, we screened 693 women, of whom 540 were randomly assigned to immediate PrEP (n=271) or deferred PrEP (n=269). The median gestational age was 19 weeks (IQR 15-23 for immediate PrEP and 16-23 for deferred PrEP). The risk difference between the immediate PrEP group and the deferred PrEP group for preterm birth was -4·7% (90% CI -10·7 to 1·2; immediate PrEP was non-inferior), for very preterm birth was 0·6% (-3·4 to 4·6; upper limit exceeded the non-inferiority margin), for low birthweight was 2·5% (-1·6 to 6·6; upper limit exceeded the non-inferiority margin), for very low birthweight was 0% (-1·4 to 1·4; upper limit exceeded the non-inferiority margin), for stillbirth was 1·2% (-1·5 to 3·8; upper limit exceeded the non-inferiority margin), and for small for gestational age was 0·9% (-1·2 to 2·9; immediate PrEP was non-inferior). In our study, PrEP was not associated with preterm birth or small for gestational age infants. Our data support the use of tenofovir disoproxil fumarate and emtricitabine in pregnancy and our reassuring findings can be used to allay safety concerns among pregnant women. South African Medical Research Council and Gilead Sciences.

Impact on renal function of daily and on-demand HIV pre-exposure prophylaxis in the ANRS-PREVENIR study.

To assess the impact on the estimated glomerular filtration rate (eGFR) of different tenofovir disoproxil/emtricitabine dosing regimens for HIV pre-exposure prophylaxis (PrEP). We included in the study individuals with baseline eGFR > 50 mL/min/1.73 m2 who initiated PrEP in the ongoing ANRS-PREVENIR PrEP cohort. We retrospectively classified PrEP users in three groups: 'on-demand' (reported at ≥75% of study visits), 'daily' (≥75% of study visits) or 'switches'. We compared the area under curve (AUC) of the eGFR variation from baseline (ΔeGFR) between groups using analysis of covariance, and assessed factors associated with a negative AUC of ΔeGFR. From May 2017 to October 2020, 1253 PrEP-naïve participants (98% of MSM) were included in the study with a median follow-up of 22 months. 499 (40%), 494 (39%) and 260 (21%) users were in the group daily, on-demand and switches, respectively, for a median number of pills taken per week of 6, 1.7 and 4. The mean AUC of the ΔeGFR was -1.09 mL/min/1.73 m2 in the daily PrEP group, -0.69 mL/min/1.73 m2 in the switches group and +0.18 mL/min/1.73 m2 with on-demand PrEP. In a model adjusted on baseline age and eGFR, the AUC of the ΔeGFR was significantly higher with on-demand PrEP compared to daily PrEP (P = 0.037). Independent factors associated with a negative AUC of ΔeGFR were a daily PrEP regimen, a switches regimen, an age > 40 years and a baseline eGFR≥90 mL/min/1.73 m². On-demand PrEP dosing had a smaller impact on eGFR evolution than daily PrEP, but the difference was not clinically relevant.

Vaginal microbial shifts are unaffected by oral pre-exposure prophylaxis in South African women

Vaginal microbiota have been shown to be a modifier of protection offered by topical tenofovir in preventing HIV infection in women, an effect not observed with oral tenofovir-based pre-exposure prophylaxis (PrEP). It remains unclear whether PrEP can influence the vaginal microbiota composition. This study investigated the impact of daily oral tenofovir disoproxil fumarate in combination with emtricitabine for PrEP on the vaginal microbiota in South African women. At baseline, Lactobacillus iners or Gardnerella vaginalis dominant vaginal communities were observed in the majority of participants. In cross sectional analysis, vaginal microbiota were not affected by the initiation and use of PrEP. Longitudinal analysis revealed that Lactobacillus crispatus-dominant “cervicotypes 1 (CT1)” communities had high probability of remaining stable in PrEP group, but had a higher probability of transitioning to L. iners-dominant CT2 communities in non-PrEP group. L. iners-dominant communities were more likely to transition to communities associated with bacterial vaginosis (BV), irrespective of PrEP or antibiotic use. As expected, BV-linked CTs had a higher probability of transitioning to L. iners than L. crispatus dominant CTs and this shift was not associated with PrEP use.

Are We Hitting the Target? HIV Pre-Exposure Prophylaxis from 2012 to 2020 in the OPERA Cohort.

Preventing HIV transmission is a crucial step in ending the HIV epidemic. Safe and effective pre-exposure prophylaxis (PrEP) has been available in the United States since 2012. We set out to determine if persons at greatest risk for HIV acquisition were receiving HIV PrEP. HIV-negative individuals from the Observational Pharmaco-Epidemiology Research & Analysis (OPERA) cohort who were prescribed daily PrEP were contrasted with newly diagnosed HIV persons without PrEP use between July 16, 2012 and October 31, 2020 to determine if the PrEP prescriptions reached the populations who were seroconverting. Poisson regression was used to estimate incidence rates of seroconversion to HIV among PrEP initiators, as well as new diagnoses of sexually transmitted infections among both the PrEP group and the newly HIV+ group. Out of the 14,598 PrEP users and 3558 persons newly diagnosed with HIV in OPERA, demographics varied widely. Older individuals, those of non-Black race, men, nonintravenous (IV) drug users, and those with commercial insurance were proportionally overrepresented among those prescribed PrEP compared to persons newly diagnosed with HIV during the same time period. Over 82% of new HIV+ individuals received care in the southern United States compared to only 45% of PrEP users. Seroconversion to HIV among PrEP users was generally uncommon, although more frequent among those who identified as Black individuals, especially in the 13-25 years old age range. In conclusion, providers need innovative programs to better identify, educate, and link those at greatest risk of HIV acquisition, especially young people, women, Black individuals, and IV drug users, to PrEP.

Sexually transmitted infections knowledge in different populations attending a French University Hospital-A prospective observational study.

Abstract We conducted a prospective study about sexually transmitted infections (STIs) knowledge in different populations attending Lyon's University Hospitals in order to estimate awareness on STIs. Pre-exposure prophylaxis (PrEP)-users (PrEP group), persons living with HIV (PLWH group) and persons undergoing free STI screening (screening group) filled an anonymous questionnaire evaluating STI knowledge. A composite STI knowledge score was calculated and was correlated with patients’ characteristics. A total of 756 patients were enrolled in three groups: screening (n = 509), PrEP (n = 103) and PLWH (n = 144). STI transmission knowledge was better for HIV than for other STIs. The median STI knowledge score was significantly higher in PrEP-users than in the screening and PLWH groups. PrEP use and a previous STI diagnosis were independently associated with a higher score. PrEP-users have better STI knowledge than PLWH and persons undergoing free STI screening. Sexual health promotion interventions routinely reserved to PrEP-users in France seem to be effective in raising the awareness of this group for STIs. Continuous efforts are justified for PLWH and the younger layers of the population.

Altered Antibody Responses in Persons Infected with HIV-1 While Using Preexposure Prophylaxis.

Preexposure prophylaxis (PrEP) is an effective HIV prevention tool, although effectiveness is dependent upon adherence. It is important to characterize the impact of PrEP on HIV antibody responses in people who experience breakthrough infections to understand the potential impact on timely diagnosis and treatment. Longitudinal HIV-1-specific antibody responses were evaluated in 42 people who inject drugs (PWID) from the Bangkok Tenofovir Study (BTS) (placebo = 28; PrEP = 14) who acquired HIV while receiving PrEP. HIV-1 antibody levels and avidity to three envelope proteins (gp41, gp160, and gp120) were measured in the plasma using a customized Bio-Plex (Bio-Rad Laboratories, Hercules, CA) assay. A time-to-event analysis was performed for each biomarker to compare the distribution of times at which study subjects exceeded the recent/long-term assay threshold, comparing PrEP and placebo treatment groups. We fit mixed-effects models to identify longitudinal differences in antibody levels and avidity between groups. Overall, longitudinal antibody levels and avidity were notably lower in the PrEP breakthrough group compared to the placebo group. Time-to-event analyses demonstrated a difference in time to antibody reactivity between treatment groups for all Bio-Plex biomarkers. Longitudinal gp120 antibody levels within the PrEP breakthrough group were decreased compared to the placebo group. When accounting for PrEP adherence, both gp120 and gp160 antibody levels were lower in the PrEP breakthrough group compared to the placebo group. We demonstrate hindered envelope antibody maturation in PWID who became infected while receiving PrEP in the BTS, which has significant implications for HIV diagnosis. Delayed maturation of the antibody response to HIV may increase the time to detection for antibody-based tests. Clinical Trial Registration Number, NCT00119106.

Preventive Efficacy of Tenofovir/Emtricitabine Against Severe Acute Respiratory Syndrome Coronavirus 2 Among Pre-Exposure Prophylaxis Users.

BackgroundThe preventive effect that tenofovir/emtricitabine (FTC) could have against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in human immunodeficiency virus-negative people is unknown. The objective of this study was to analyze the seroprevalence and clinical manifestations of COVID-19 among users of pre-exposure prophylaxis (PrEP), disoproxil fumarate/FTC (TDF/FTC), or tenofovir alafenamide (TAF)/FTC and to compare it to that of a control group.MethodsAn observational descriptive study of the seroprevalence of antibodies for SARS-CoV-2 among men who have sex with men and transgender women without use of PrEP (Group 1; n = 250) and PrEP users with TDF/FTC (n = 409) or TAF/FTC (n = 91) (Group 2; n = 500) was conducted from May11, 2020 to June 27, 2020. All participants were provided with a structured questionnaire that collected information on the variables to be analyzed, and testing for immunoglobulin G antibodies to SARS-CoV-2 (chemiluminescent microparticle immunoassay) was then carried out.ResultsThe seroprevalence of SARS-CoV-2 was 9.2% (95% confidence interval [CI], 5.9–13.5) in the group without PrEP and 15.0% (95% CI, 12.0–18.4) in the group with PrEP (P = .026). Among users of TDF/FTC it was 14.7% (95% CI, 11.4–18.5), and in users of TAF/FTC it was 16.5% (95% CI, 9.5–25.7) (P = .661). In those who tested positive for SARS-CoV-2 and receiving PrEP, 57.4% manifested symptoms, compared with 78.3% in the control group (P = .070). In users of TDF/FTC the figure was 53.3% and in users of TAF/FTC the figure was 73.3% (P = .100). The duration of symptoms was 11.5 days in the control group, 9.0 days in PrEP users (P = .116), 7.0 days in users of TDF/FTC, and 13.0 days in users of TAF/FTC (P = .100).ConclusionsUsers of PrEP, TDF/FTC, or TAF/FTC presented a higher seroprevalence to SARS-CoV-2 than the control group. No statistically significant differences were found in relation to clinical manifestations. The PrEP users should use the same prevention measures as those indicated for the general population.

Study on Pre-Exposure Prophylaxis Regimens among Men Who Have Sex with Men: A Prospective Cohort Study.

Background: There are limited studies on the medication regimen of pre-exposure prophylaxis (PrEP) among men who have sex with men (MSM) in China. This study compared the effectiveness of and adherence to two prophylactic HIV medication regimens, which provided evidence and guidance for the application and promotion of the PrEP strategy in the MSM population in China. Methods: We conducted an open, non-randomized, multicenter, parallel, controlled clinical intervention study in western China. Subjects were recruited by convenience sampling at research centers in Chongqing, Guangxi, Xinjiang and Sichuan, China from April 2013 to March 2015, and they were categorized into the daily PrEP, event-driven and blank control groups. Tenofovir disoproxil fumarate (TDF; 300 mg/dose) was administered to subjects in the daily PrEP and event-driven groups, and all subjects were followed up every 12 weeks for 96 weeks. Demographic, behavioral, psychological characteristics and AIDS-related attitudes were assessed using self-completed questionnaires. TDF serum concentrations in subjects in Chongqing and Sichuan were quantified after systematic sampling. Results: Of the 2422 enrolled MSM, 856 were eligible for statistical analysis (PrEP group: 385 and event-driven group: 471); 30 and 32 subjects in daily PrEP and event-driven groups, respectively, were HIV-positive; the incidence of HIV infection was as follows: daily PrEP group, 6.60 cases/100 person-years and event-driven group, 5.57 cases/100 person-years (relative risk (RR) 95% confidence interval (CI) was 0.844 (0.492–1.449)); HIV incidence did not differ significantly when stratified by medication adherence or sites. When the medication adherence rate was ≥80%, the median TDF serum concentrations were 0.458 mg/L, and 0.429 mg/L in the daily PrEP, and event-driven groups, respectively (not significant; p > 0.05); Subjects who were in the event-driven PrEP group (OR = 2.152, 95% CI: 1.566–2.957), had fewer male sexual partners in the last two weeks (OR = 0.685, 95% CI: 0.563–0.834), were one year older on average (OR = 1.022, 95% CI: 1.002–1.043), considered that medication kept them safe, were less worried about others knowing they took medicine and were more likely to have high adherence. Conclusions: The efficacies of daily TDF and event-driven TDF use were not significantly different in preventing new infections among HIV-negative MSM. Event-driven TDF use is economical and effective and is worth popularizing. Our results provide evidence for the application and promotion of the PrEP strategy in the MSM population in China.

Differences Between Groups of Pre-exposure Prophylaxis (PrEP) Using Couples in HIV-Negative/Unknown Relationships.

Epidemiology research is limited on the characteristics of HIV pre-exposure prophylaxis (PrEP) using couples. US nationwide sample recruited online in 2017. HIV negative/unknown gay, bisexual, and other men who have sex with men with HIV negative/unknown partners (n = 3140) were asked about individual and main partner PrEP uptake. Men were coded into the following 5 groups: (1) neither participant nor partner on PrEP, (2) partner only on PrEP, (3) participant only on PrEP, (4) both on PrEP, and (5) unknown partner PrEP use. We examined associations of demographics, relationship factors, condomless anal sex (CAS) with main and causal partners, bacterial sexually transmitted infection diagnoses, and sexual positioning with reported dyadic PrEP use using fully adjusted multinomial logistic regressions. PrEP use was 3.2% for the partner only, 5.7% for the participant only, and 4.9% for both the participant and partner; 5.6% reported not knowing their partner's PrEP use status. Men who reported any CAS with their main partner or any CAS with male casual partners were both more likely to be classified in the dyadic PrEP use group compared with the neither on PrEP group. Compared with monogamous, men in open arrangements were more likely to be classified in each of the 3 PrEP groups compared with the neither on PrEP group. Six-month bacterial sexually transmitted infection prevalence was 2.8%, 8.1%, 8.3%, 15.6%, and 4.0% for the 5 groups, respectively. PrEP use occurred during times of higher risk behavior engagement, but further efforts are needed to expand PrEP use to more partnered gay, bisexual, and other men who have sex with men.

Sexual behaviour and incidence of HIV and sexually transmitted infections among men who have sex with men using daily and event-driven pre-exposure prophylaxis in AMPrEP: 2 year results from a demonstration study

Pre-exposure prophylaxis (PrEP) for HIV might induce risk compensation, defined as increased sexual risk behaviour leading to increased incidence of bacterial sexually transmitted infections (STIs). We examined the incidence of HIV, STIs, and sexual behaviour after initiating daily and event-driven PrEP. AMPrEP is a demonstration study that assessed the incidence of HIV and bacterial STIs and sexual behaviour among PrEP users at the STI clinic of the Public Health Service of Amsterdam (Amsterdam, the Netherlands). Eligible adults (aged ≥18 years) were HIV-negative men who have sex with men (MSM) and transgender people who had reported one or more of the following in the previous 6 months: condomless anal sex with casual partners, at least one bacterial STI, use of post-exposure prophylaxis after a sexual risk incident, or an HIV-positive sexual partner with detectable viral load. Participants were given a choice of daily PrEP or event-driven PrEP regimens. Participants were seen every 3 months for HIV and STI testing. Participants also completed self-administered questionnaires about sexual behaviour at each visit. Over the first 2 years, we assessed the number and incidence rate of HIV and chlamydia, gonorrhoea, and syphilis, including STIs diagnosed in between study visits and assessed changes in incidence over time using piecewise exponential survival models. The number of sexual acts and sexual partners were also analysed and changes over time were assessed using negative binomial regression models. This study is ongoing; the data cutoff for this analysis was June 30, 2018. Between Aug 3, 2015, and May 31, 2016, 376 participants were recruited, of whom nine participants were lost to follow-up, thus 367 participants were included in the analysis. Overall, 365 MSM and two transgender women were included, contributing 681·7 person-years of follow-up. At enrolment, 269 (73%) of 367 participants chose daily PrEP and 98 (27%) participants chose event-driven PrEP. Two individuals in the daily PrEP group became HIV-positive; overall HIV incidence rate was 0·30 per 100 person-years (95% CI 0·07-1·19). 253 participants were diagnosed with one or more STI during the first 2 years (incidence rate 90·4 per 100 person-years). STI incidence did not change over time (adjusted incidence rate ratio [aIRR] 1·00 per 3 month follow-up, 95% CI 0·93-1·07). More than a quarter of all STIs were diagnosed from tests done in between study visits. STI incidence was lower in the event-driven PrEP group than the daily PrEP group (aIRR 0·59, 95% CI 0·46-0·75). The number of condomless anal sex acts with casual partners per 3 months increased, but the number of partners and sex acts remained stable. Although the overall incidence of STIs did not change during 2 years of PrEP use, the incidence of STIs was higher among participants using daily PrEP than those using event-driven PrEP, which is likely a result of differences in sexual behaviour. This finding suggests the need to tailor STI prevention interventions according to behavioural profiles. ZonMw, H-TEAM, Internal GGD research funds, Aidsfonds, Stichting AmsterdamDiner Foundation, Gilead Sciences, Janssen Pharmaceutica, M A C AIDS Fund, and ViiV Healthcare.

Sexual Risk Compensation in a Pre-exposure Prophylaxis Demonstration Study Among Individuals at Risk of HIV.

A public health concern regarding HIV pre-exposure prophylaxis (PrEP) is sexual risk compensation (ie, increased unsafe sex among PrEP users that may undermine prevention efforts). This demonstration study (NCT#01761643; initiated in 2013) included 398 men who have sex with men who initiated PrEP and were followed over 48 weeks at 4 sites in Southern California. Wilcoxon signed-rank tests compared previous 30-day number of sex partners and condomless insertive anal sex and receptive anal sex (CIAS and CRAS, respectively) acts at weeks 4, 12, 24, 36, and 48 to baseline. At 2 sites, PrEP users were also compared with a lagged, comparison group of 99 men who have sex with men who did not receive PrEP over 24 weeks using linear regression models, adjusting for age, race/ethnicity, education, and respective baseline scores. Logistic regression compared week 24 sexually transmitted infection (STI) rates. Over 48 weeks in the PrEP group, there were significant decreases in the number of unknown HIV status sex partners and increases in CRAS at all study visits; there was no consistent change in number of HIV+ sex partners or CIAS. Among participants at 2 sites, there were no significant differences between PrEP and non-PrEP users in change in number of partners, CIAS, CRAS, or STI rates at week 24. Among early adopters of PrEP, there is some evidence for sexual risk compensation. Results support current guidelines of regular STI screening and behavioral risk reduction and adherence counseling with the provision of PrEP.

HIV pre-exposure prophylaxis and early antiretroviral treatment among female sex workers in South Africa: Results from a prospective observational demonstration project.

BackgroundOperational research is required to design delivery of pre-exposure prophylaxis (PrEP) and early antiretroviral treatment (ART). This paper presents the primary analysis of programmatic data, as well as demographic, behavioural, and clinical data, from the TAPS Demonstration Project, which offered both interventions to female sex workers (FSWs) at 2 urban clinic sites in South Africa.Methods and findingsThe TAPS study was conducted between 30 March 2015 and 30 June 2017, with the enrolment period ending on 31 July 2016. TAPS was a prospective observational cohort study with 2 groups receiving interventions delivered in existing service settings: (1) PrEP as part of combination prevention for HIV-negative FSWs and (2) early ART for HIV-positive FSWs. The main outcome was programme retention at 12 months of follow-up. Of the 947 FSWs initially seen in clinic, 692 were HIV tested. HIV prevalence was 49%. Among those returning to clinic after HIV testing and clinical screening, 93% of the women who were HIV-negative were confirmed as clinically eligible for PrEP (n = 224/241), and 41% (n = 110/270) of the women who were HIV-positive had CD4 counts within National Department of Health ART initiation guidelines at assessment. Of the remaining women who were HIV-positive, 93% were eligible for early ART (n = 148/160). From those eligible, 98% (n = 219/224) and 94% (n = 139/148) took up PrEP and early ART, respectively. At baseline, a substantial fraction of women had a steady partner, worked in brothels, and were born in Zimbabwe. Of those enrolled, 22% on PrEP (n = 49/219) and 60% on early ART (n = 83/139) were seen at 12 months; we observed high rates of loss to follow-up: 71% (n = 156/219) and 30% (n = 42/139) in the PrEP and early ART groups, respectively. Little change over time was reported in consistent condom use or the number of sexual partners in the last 7 days, with high levels of consistent condom use with clients and low use with steady partners in both study groups. There were no seroconversions on PrEP and 7 virological failures on early ART among women remaining in the study. Reported adherence to PrEP varied over time between 70% and 85%, whereas over 90% of participants reported taking pills daily while on early ART. Data on provider-side costs were also collected and analysed. The total cost of service delivery was approximately US$126 for PrEP and US$406 for early ART per person-year. The main limitations of this study include the lack of a control group, which was not included due to ethical considerations; clinical study requirements imposed when PrEP was not approved through the regulatory system, which could have affected uptake; and the timing of the implementation of a national sex worker HIV programme, which could have also affected uptake and retention.ConclusionsPrEP and early ART services can be implemented within FSW routine services in high prevalence, urban settings. We observed good uptake for both PrEP and early ART; however, retention rates for PrEP were low. Retention rates for early ART were similar to retention rates for the current standard of care. While the cost of the interventions was higher than previously published, there is potential for cost reduction at scale. The TAPS Demonstration Project results provided the basis for the first government PrEP and early ART guidelines and the rollout of the national sex worker HIV programme in South Africa.

Statistical issues in trials of preexposure prophylaxis.

Purpose of reviewWe discuss selected statistical issues in the design and analysis of preexposure prophylaxis (PrEP) trials. The general principles may inform thinking for other interventions in HIV prevention.Recent findingsTo date, four different designs have been used to determine the effectiveness of PrEP: randomized, double-blind, placebo-controlled; randomized, open-label, immediate or delayed access; nonrandomized comparison of HIV incidence according to the level of drug detected; comparison of the observed HIV incidence to the expected rate using historical control data. Open-label trials of PrEP, which assess public health effectiveness, complement the placebo-controlled trials which established the biological efficacy of TDF/ FTC. Future trials of PrEP will be highly challenging to design since a no PrEP group is difficult to justify and the natural control regimen, TDF/FTC, is highly efficacious.SummaryStandard statistical paradigms for noninferiority trials should be reconsidered for evaluating alternative PrEP regimens.