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.

BACKGROUND: 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. METHODS: 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. FINDINGS: 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. INTERPRETATION: 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. FUNDING: Division of AIDS at the National Institute of Allergy and Infectious Diseases, ViiV Healthcare, and Gilead Sciences.

Extended Analysis of HIV Infection in Cisgender Men and Transgender Women Who Have Sex with Men Receiving Injectable Cabotegravir for HIV Prevention: HPTN 083.

HPTN 083 demonstrated that injectable cabotegravir (CAB) was superior to oral tenofovir disoproxil fumarate-emtricitabine (TDF-FTC) for HIV prevention in cisgender men and transgender women who have sex with men. We previously analyzed 58 infections in the blinded phase of HPTN 083 (16 in the CAB arm and 42 in the TDF-FTC arm). This report describes 52 additional infections that occurred up to 1 year after study unblinding (18 in the CAB arm and 34 in the TDF-FTC arm). Retrospective testing included HIV testing, viral load testing, quantification of study drug concentrations, and drug resistance testing. The new CAB arm infections included 7 with CAB administration within 6 months of the first HIV-positive visit (2 with on-time injections, 3 with ≥1 delayed injection, and 2 who restarted CAB) and 11 with no recent CAB administration. Three cases had integrase strand transfer inhibitor (INSTI) resistance (2 with on-time injections and 1 who restarted CAB). Among 34 CAB infections analyzed to date, diagnosis delays and INSTI resistance were significantly more common in infections with CAB administration within 6 months of the first HIV-positive visit. This report further characterizes HIV infections in persons receiving CAB preexposure prophylaxis and helps define the impact of CAB on the detection of infection and the emergence of INSTI resistance.

HIV RNA Screening Reduces Integrase Strand Transfer Inhibitor Resistance Risk in Persons Receiving Long-Acting Cabotegravir for HIV Prevention.

BACKGROUND: The HPTN 083 trial demonstrated that long-acting cabotegravir (CAB-LA) was superior to tenofovir-disoproxil fumarate/emtricitabine for human immunodeficiency virus (HIV) preexposure prophylaxis (PrEP). Integrase strand transfer inhibitor (INSTI) resistance-associated mutations (RAMs) were detected in some participants with HIV infection. We used a low viral load INSTI genotyping assay to evaluate the timing of emergence of INSTI RAMs and assessed whether HIV screening with a sensitive RNA assay would have detected HIV infection before INSTI resistance emerged. METHODS: Single-genome sequencing to detect INSTI RAMs was performed for samples with viral loads <500 copies/mL from 5 participants with previously identified INSTI RAMs and 2 with no prior genotyping results. RESULTS: Major INSTI RAMs were detected in all 7 cases. HIV RNA testing identified infection before major INSTI RAMs emerged in 4 cases and before additional major INSTI RAMs accumulated in 1 case. Most INSTI RAMs were detected early when the viral load was low and CAB concentration was high. CONCLUSIONS: When using CAB-LA PrEP, earlier detection of HIV infection with a sensitive RNA assay may allow for earlier treatment initiation with the potential to reduce INSTI resistance risk. Further studies are needed to evaluate the value and feasibility of HIV RNA testing with CAB-LA PrEP.

Low incidence and prevalence of hepatitis C in two cohorts of HIV pre-exposure prophylaxis adherence interventions in men who have sex with men in Southern California.

HIV pre-exposure prophylaxis (PrEP) has been associated with incident hepatitis C virus (HCV) infection in men who have sex with men (MSM) due to decreased condom use. We examined rates of HCV among MSM and transgender women at high-risk of HIV on PrEP in Southern California using data from two trials (NCT01761643 and NCT01781806). Five of 599 participants (0.84%, 95% CI, 0.27-1.93) had HCV antibodies detected at entry. Factors associated with HCV seropositivity included being older (p = .002) and lower education level (p < .001). HCV-positive participants had no reported cases of sexually transmitted infection (rectal, urethral or pharyngeal gonorrhoea and/or chlamydia) at entry while HCV-negative participants had a prevalence of 18% (95% CI, 15%-21%). There were no significant differences in substance use and sexual risk behaviour between HCV-positive and HCV-negative participants 1-3 months prior to entry. Among early PrEP adopters, incident HCV did not occur despite ongoing condomless intercourse. Screening intervals for HCV in MSM on PrEP should be led by a risk behaviour assessment.

Characterization of Human Immunodeficiency Virus (HIV) Infections in Women Who Received Injectable Cabotegravir or Tenofovir Disoproxil Fumarate/Emtricitabine for HIV Prevention: HPTN 084.

BACKGROUND: HIV Prevention Trials Network 084 demonstrated that long-acting injectable cabotegravir (CAB) was superior to daily oral tenofovir (TFV) disoproxil fumarate (TDF)/emtricitabine (FTC) for preventing human immunodeficiency virus (HIV) infection in sub-Saharan African women. This report describes HIV infections that occurred in the trial before unblinding. METHODS: Testing was performed using HIV diagnostic assays, viral load testing, a single-copy RNA assay, and HIV genotyping. Plasma CAB, plasma TFV, and intraerythrocytic TFV-diphosphate concentrations were determined by liquid chromatography-tandem mass spectrometry. RESULTS: Forty HIV infections were identified (CAB arm, 1 baseline infection, 3 incident infections; TDF/FTC arm, 36 incident infections). The incident infections in the CAB arm included 2 with no recent drug exposure and no CAB injections and 1 with delayed injections; in 35 of 36 cases in the TDF/FTC arm, drug concentrations indicated low or no adherence. None of the cases had CAB resistance. Nine women in the TDF/FTC arm had nonnucleoside reverse-transcriptase inhibitor resistance; 1 had the nucleoside reverse-transcriptase inhibitor resistance mutation, M184V. CONCLUSIONS: Almost all incident HIV infections occurred in the setting of unquantifiable or low drug concentrations. CAB resistance was not detected. Transmitted nonnucleoside reverse-transcriptase inhibitor resistance was common; 1 woman may have acquired nucleoside reverse-transcriptase inhibitor resistance from study drug exposure.

Pre-Exposure Prophylaxis Perspectives, Sociodemographic Characteristics, and HIV Risk Profiles of Cisgender Women Seeking and Initiating PrEP in a US Demonstration Project.

Little information is known about the cisgender women who seek and initiate pre-exposure prophylaxis (PrEP) for HIV prevention in the United States. Adherence Enhancement Guided by Individualized Texting and Drug Levels was a 48-week single-arm open-label demonstration study of daily oral tenofovir disoproxil fumaratel emtricitabine (TDF/FTC) in cisgender women ≥ 18 years old at risk for HIV. Participants were surveyed at screening and enrollment about sociodemographics, HIV risk perception and behaviors, and PrEP perspectives and aggregated into three risk groups according to HIV sexual risk behavior: being in a serodiscordant partnership (SD), engaging in sex work (SW), and having partners with unknown HIV status at risk for HIV (UP). One hundred sixty-seven women presented for screening with n = 31 screen failures. Of the 162 women completing enrollment, mean age was 40 (standard deviation 11), with 41% non-Hispanic Black, 22% non-Hispanic White, and 19% Latina. Compared with those who screened ineligible, enrolled participants were more likely to have heard of PrEP, had higher HIV risk perception, and reported higher perceived PrEP efficacy. Sixty-four women (47%) were categorized as SD, 21 (15%) as SW, and 51 (38%) as UP. The SW were more likely to report higher levels of drinking and drug use (p = 0.002) and history of intimate partner violence in the past year (p < 0.001) compared with SD and UP. Among cisgender women enrolled, there were significant differences between the three risk groups by demographics, HIV risk behavior, and PrEP perspectives, suggesting that interventions to successfully implement PrEP in US women may need to be tailored by HIV risk group. Clinical Trial Registration number: NCT02584140.

Results from a Pre-exposure Prophylaxis Demonstration Project for At-risk Cisgender Women in the United States.

BACKGROUND: Daily oral tenofovir disoproxil fumarate/emtricitabine (TDF/FTC) is effective for reducing human immunodeficiency virus (HIV) acquisition among cisgender women. We report results from the first US observational open-label demonstration project of pre-exposure prophylaxis (PrEP) among at-risk cisgender women. METHODS: Adherence Enhancement Guided by Individualized Texting and Drug Levels was a 48-week, single-arm, open-label demonstration study of daily oral TDF/FTC in cisgender women ≥18 years old at risk for HIV. Adherence was supported using 2-way text messaging and titrated adherence counseling based on rapid-turnaround tenofovir diphosphate concentrations from dried blood spots. Study visits occurred at baseline, weeks 4 and 12, and quarterly through week 48. Outcomes included TDF/FTC adherence, retention, and persistence. RESULTS: From June 2016 to October 2018, 136 cisgender women enrolled (mean age, 40 years (standard deviation, 11); 38% non-Hispanic Black and 19% Latina). At 48 weeks, 84 (62%) participants were retained and 62 (46%) remained on PrEP. More than one-third (12/31) of those on study but off PrEP throughout the study discontinued TDF/FTC because of side effects, and 1 adverse event led to study discontinuation. Of 120 participants with drug concentrations measured, 67 (56%) had at least 1 concentration consistent with 6 doses/week; 22 (18%) had consistent ≥6 doses/week across all study visits attended. There were no incident HIV infections and 4 incident bacterial sexually transmitted infections. CONCLUSION: Adequate PrEP adherence for protective drug concentrations was not achieved for most study participants. More work needs to be done to fully explicate the reasons for nonadherence and low retention in cisgender women.

Characterization of Human Immunodeficiency Virus (HIV) Infection in Cisgender Men and Transgender Women Who Have Sex With Men Receiving Injectable Cabotegravir for HIV Prevention: HPTN 083.

BACKGROUND: The HIV Prevention Trials Network (HPTN) 083 trial demonstrated that long-acting cabotegravir (CAB-LA) was more effective than tenofovir disoproxil fumarate-emtricitabine (TDF/FTC) in preventing human immunodeficiency virus (HIV) in cisgender men and transgender women who have sex with men. We characterized HIV infections that occurred in the blinded phase of HPTN 083. METHODS: Retrospective testing included HIV testing, viral load testing, quantification of study drugs, and HIV drug resistance testing. RESULTS: Fifty-eight infections were evaluated, including 51 incident infections (12 in CAB arm and 39 in TDF/FTC arm). In many cases (5 in CAB arm and 37 in TDF/FTC arm), infection was associated with low or unquantifiable study drug concentrations. In 4 cases, infection occurred with on-time CAB-LA injections and expected plasma CAB concentrations. CAB exposure was associated with prolonged viral suppression and delayed antibody expression. In some cases, delayed HIV diagnosis resulted in CAB provision to participants with undetected infection, delayed antiretroviral therapy, and emergence of drug resistance; most of these infections would have been detected earlier with viral load testing. CONCLUSIONS: Early detection of HIV infection and prompt antiretroviral therapy initiation could improve clinical outcomes in persons who become infected despite CAB-LA prophylaxis. Further studies are needed to elucidate the correlates of HIV protection in persons receiving CAB-LA.

PrEP Nonadherence, White Coat Dosing, and HIV Risk Among a Cohort of MSM.

Among a cohort of men who have sex with men in a pre-exposure prophylaxis (PrEP) adherence trial, syphilis requiring treatment was associated with white coat dosing (increased PrEP adherence immediately preceding study visits) when compared with participants with optimal drug concentrations. The findings highlight the need for identifying and reducing barriers to PrEP adherence.

Tail-phase safety, tolerability, and pharmacokinetics of long-acting injectable cabotegravir in HIV-uninfected adults: a secondary analysis of the HPTN 077 trial.

BACKGROUND: Long-acting injectable cabotegravir is a novel integrase inhibitor currently in advanced clinical development for HIV prevention and treatment. We aimed to assess the terminal phase pharmacokinetics and safety of long-acting injectable cabotegravir in participants included in the HPTN 077 trial. METHODS: HPTN 077 was a multicentre, double-blind, randomised, placebo-controlled phase 2a trial done at eight sites in Brazil, Malawi, South Africa, and the USA. Participants (aged 18-65 years), who were HIV-uninfected and at low-risk for HIV, were randomly assigned (3:1) to long-acting injectable cabotegravir (800 mg given three times at 12 week intervals or 600 mg given five times, administered at one 4 week interval, and every 8 weeks thereafter) or placebo. Participants were followed up to 76 weeks after final injection. In a prespecified analysis of secondary and exploratory outcomes, we assessed the safety, measured by the proportion of participants with grade 2 or worse adverse events, and pharmacokinetics, measured by apparent terminal phase half-life (t1/2app) and estimated time to lower limit of quantification (LLOQ) of long-acting injectable cabotegravir during the injection phase (defined as the time between first injection and 12 weeks or 8 weeks after the last injection in cohort 1 or cohort 2 respectively) and tail phase (defined as the time between final injection and 52-76 weeks post-final injection). Safety was analysed in all participants who received at least one injection. Pharmacokinetic analyses included all participants who had received at least one injection and had at least three cabotegravir measurements higher than the LLOQ after the final injection. Pharmacokinetic outcomes were estimated using non-compartmental methods. The trial is completed, and was registered with ClinicalTrials.gov, NCT02178800. FINDINGS: Between Feb 9, 2015, and May 27, 2016, 177 participants (134 participants in the cabotegravir group [74 participants in cohort 1; 60 participants in cohort 2] and 43 participants in the placebo group [25 participants in cohort 1; 18 participants in cohort 2) were enrolled and received at least one injection and thus were included in the safety analysis. The incidence of grade 2 or worse adverse events was significantly lower during the tail phase than the injection phase (p<0·0001). At 52-60 weeks after final injection, nine (23%) of 40 male participants had detectable cabotegravir concentrations and at week 76, four (13%) of 30 male participants had detectable cabotegravir concentrations compared with 52 (63%) of 82 female participants and 27 (42%) of 64 female participants at the same timepoints. The median time from the last injection to the time when cabotegravir concentration decreased below the LLOQ was 43·7 weeks (IQR 31·1-66·6; range 20·4-152·5) for male participants and 67·3 weeks (29·1-89·6; 17·7-225·5) for female participants (p=0·0003). t1/2app was longer for female participants than male participants (geometric mean fold-change 1·33, 95% CI 1·06-1·68; p=0·014), and longer for participants with a high body-mass index (BMI) than those with a low BMI (1·31, 1·06-1·63; p=0·015). INTERPRETATION: The clinical significance of the long pharmacokinetic tail of cabotegravir observed in female participants compared with male participants, and those with higher BMI compared with a lower BMI, need to be addressed in future trials. FUNDING: National Institute of Allergy and Infectious Diseases.

Cabotegravir Is Not Associated With Weight Gain in Human Immunodeficiency Virus-uninfected Individuals in HPTN 077.

Studies in human immunodeficiency virus (HIV)-infected individuals suggest excess weight gain with integrase inhibitor-based antiretroviral therapy. The HIV Prevention Trials Network Study 077 evaluated changes in weight and fasting metabolic parameters in HIV-uninfected individuals randomized to cabotegravir or a placebo. No differences between arms were found for change in weight or fasting metabolic parameters overall or for subgroups.

Long-acting injectable cabotegravir for the prevention of HIV infection.

PURPOSE OF REVIEW: This review highlights the development of long-acting injectable cabotegravir (CAB LA) for HIV preexposure prophylaxis (PrEP), with a focus on phase 2 studies and later development. RECENT FINDINGS: Early studies of CAB LA for HIV prevention offered promising pharmacokinetic data and paved the way for phase 2 studies, which have now been completed. On the basis of phase 2 data, dosing of CAB LA at 8-week intervals consistently delivers target trough concentrations in both men and women. Recent studies have shown no required dose adjustments for hepatic or renal disease and minimal drug--drug interactions. Additionally, injectable PrEP is desired by potential PrEP candidates. Still, gaps in knowledge remain with respect to implementation and delivery, the clinical significance of the pharmacologic tail, and dosing in key populations. Phase 3 trials are underway that are anticipated to inform some of these questions and provide efficacy and safety data to support regulatory submissions for CAB LA as a potential PrEP agent. SUMMARY: Recent studies have defined an appropriate CAB LA dosing interval and offered insight into its safety profile. Phase 3 studies will provide much-anticipated efficacy data. If efficacious, CAB LA may provide a desirable PrEP option for those who face challenges to daily pill adherence. A more complete understanding of how to best integrate LA PrEP into service delivery models will be critical for success.

Effective use of pre-exposure prophylaxis (PrEP) Among stimulant users with multiple condomless sex partners: a longitudinal study of men who have sex with men in Los Angeles.

PrEP's potential benefit for men who have sex with men (MSM) who use stimulants may be limited by adherence or prescriber willingness to recommend PrEP due to concerns of non-compliance. Using data from PATH-PrEP, a 48-week study evaluating PrEP for MSM in Los Angeles, we modeled an interaction between stimulant use and condomless sex with multiple partners (CAS-MP) on prevention-effective dried blood spot tenofovir-diphosphate concentrations. At week 4, participants reporting stimulant use and CAS-MP had a decreased odds of prevention-effective adherence compared to non-stimulant use and non-CAS-MP (AOR 0.15, 95% CI 0.04-0.57). From week 4-48, participants reporting stimulant use and CAS-MP had increased odds of prevention-effective adherence (AOR 1.06 per week, 95%CI 1.01-1.12). Participants reporting CAS-MP without stimulant use had no significant change in prevention-effective adherence (AOR 0.99 per week, 95%CI 0.96-1.02). Stimulant use moderated the association of CAS-MP on prevention-effective PrEP adherence over time.

Safety, tolerability, and pharmacokinetics of long-acting injectable cabotegravir in low-risk HIV-uninfected individuals: HPTN 077, a phase 2a randomized controlled trial.

BACKGROUND: Cabotegravir (CAB) is a novel strand-transfer integrase inhibitor being developed for HIV treatment and prevention. CAB is formulated both as an immediate-release oral tablet for daily administration and as a long-acting injectable suspension (long-acting CAB [CAB LA]) for intramuscular (IM) administration, which delivers prolonged plasma exposure to the drug after IM injection. HIV Prevention Trials Network study 077 (HPTN 077) evaluated the safety, tolerability, and pharmacokinetics of CAB LA in HIV-uninfected males and females at 8 sites in Brazil, Malawi, South Africa, and the United States. METHODS AND FINDINGS: HPTN 077 was a double-blind, placebo-controlled phase 2a trial. Healthy individuals age 18-65 years at low HIV risk were randomized (3:1) to receive CAB or placebo (PBO). In the initial oral phase, participants received 1 daily oral tablet (CAB or PBO) for 4 weeks. Those without safety concerns in the oral phase continued and received injections in the injection phase (Cohort 1: 3 injections of CAB LA 800 mg or 0.9% saline as PBO IM every 12 weeks for 3 injection cycles; Cohort 2: CAB LA 600 mg or PBO IM for 5 injection cycles; the first 2 injections in Cohort 2 were separated by 4 weeks, the rest by 8 weeks). The primary analysis included weeks 5 to 41 of study participation, encompassing the injection phase. The cohorts were enrolled sequentially. Primary outcomes were safety and tolerability. Secondary outcomes included pharmacokinetics and events occurring during the oral and injection phases. Between February 9, 2015, and May 27, 2016, the study screened 443 individuals and enrolled 110 participants in Cohort 1 and 89 eligible participants in Cohort 2. Participant population characteristics were as follows: 66% female at birth; median age 31 years; 27% non-Hispanic white, 41% non-Hispanic black, 24% Hispanic/Latino, 3% Asian, and 6% mixed/other; and 6 transgender men and 1 transgender woman. Twenty-two (11%) participants discontinued the oral study product; 6 of these were for clinical or laboratory adverse events (AEs). Of those who received at least 1 CAB LA injection, 80% of Cohort 1 and 92% of Cohort 2 participants completed all injections; injection course completion rates were not different from those in the PBO arm. Injection site reactions (ISRs) were common (92% of Cohort 1 and 88% of Cohort 2 participants who received CAB LA reported any ISR). ISRs were mostly Grade 1 (mild) to Grade 2 (moderate), and 1 ISR event (Cohort 1) led to product discontinuation. Grade 2 or higher ISRs were the only AEs reported more commonly among CAB LA recipients than PBO recipients. Two Grade 3 (severe) ISRs occurred in CAB recipients, 1 in each cohort, but did not lead to product discontinuation in either case. Seven incident sexually transmitted infections were diagnosed in 6 participants. One HIV infection occurred in a participant 48 weeks after last injection of CAB LA: CAB was not detectable in plasma both at the time of first reactive HIV test and at the study visit 12 weeks prior to the first reactive test. Participants in Cohort 2 (unlike Cohort 1) consistently met prespecified pharmacokinetic targets of at least 95% of participants maintaining CAB trough concentrations above PA-IC90, and 80% maintaining trough concentrations above 4× PA-IC90. Study limitations include a modest sample size, a short course of injections, and a low-risk study population. CONCLUSIONS: In this study, CAB LA was well tolerated at the doses and dosing intervals used. ISRs were common, but infrequently led to product discontinuation. CAB LA 600 mg every 8 weeks met pharmacokinetic targets for both male and female study participants. The safety and pharmacokinetic results observed support the further development of CAB LA, and efficacy studies of CAB LA for HIV treatment and prevention are in progress. TRIAL REGISTRATION: ClinicalTrials.gov Registry: ClinicalTrials.gov Trial number: NCT02178800.

Results from the post-exposure prophylaxis pilot program (P-QUAD) demonstration project in Los Angeles County.

Post-exposure prophylaxis (PEP) is a promising but under-utilized strategy for HIV prevention in high-risk populations. Between March 2010 and June 2011, two community-based clinics in Los Angeles County provided PEP in a pilot program to 267 unique individuals. Courses were primarily dispensed to men who have sex with men (84%) and consisted overwhelmingly of a three-drug antiretroviral therapy regimen containing two nucleoside reverse transcriptase inhibitors and either an integrase inhibitor (raltegravir) or a boosted protease inhibitor (lopinavir/ritonavir). Approximately 64% of all PEP courses were followed for at least 12 weeks, and seven individuals seroconverted. Of the seven seroconversions, six had subsequent re-exposure. The low rate of PEP failure calls for expanded funding for PEP in other jurisdictions.

Plasma Tenofovir Levels to Support Adherence to TDF/FTC Preexposure Prophylaxis for HIV Prevention in MSM in Los Angeles, California.

BACKGROUND: Tenofovir disoproxil fumarate/emtricitabine preexposure prophylaxis (PrEP) is effective against HIV acquisition when taken as prescribed. Strategies that identify and intervene with those challenged by adherence to daily medication are needed. SETTING: PATH-PrEP was an open-label single-arm interventional cohort study conducted at 2 community-based clinical sites in Los Angeles, CA. METHODS: We enrolled self-identified men who have sex with men and transgender women ≥18 years of age at an elevated risk of HIV acquisition. Participants received a postexposure prophylaxis (PEP)-based or PrEP-based HIV prevention package for at least 48 weeks. Plasma tenofovir levels from each PrEP visit assessed as below the limit of quantitation (<10 ng/mL) triggered increased adherence support. RESULTS: Three hundred one participants enrolled. Forty-eight-week retention in the PrEP cohort was 75.1%. Biomarker evidence of PrEP adherence consistent with ≥4 doses per week at weeks 4, 12, 24, 36, and 48 was found in 83.1%, 83.4%, 75.7%, 71.6%, and 65.5% of participants, respectively; younger and African American participants were less likely to have protective drug levels. Most of those with suboptimal adherence had adherence improvement after brief intervention. One seroconversion occurred in a participant who discontinued PrEP. Nearly half (46.4%) of participants were diagnosed with at least 1 incident sexually transmitted infection during 48 weeks of study follow-up. CONCLUSIONS AND RELEVANCE: PrEP was acceptable and well tolerated in a diverse population of men who have sex with men in Los Angeles. A brief intervention triggered from biomarkers of poor adherence was associated with improved adherence. Drug level monitoring has the potential to allow targeting of additional adherence support to those struggling with daily tablet adherence.

Differentiating Nonoccupational Postexposure Prophylaxis Seroconverters and Non-Seroconverters in a Community-Based Clinic in Los Angeles, California.

BACKGROUND: Nonoccupational postexposure prophylaxis (nPEP) is a 28-day regimen of antiretroviral medications taken within 72 hours of human immunodeficiency virus (HIV) exposure to prevent HIV acquisition. Although nPEP has been recommended since 1998, few studies have analyzed the characteristics that distinguish nPEP failures (seroconverters) and successes (non-seroconverters). METHODS: This retrospective study analyzed all nPEP courses prompted by sexual exposure that were prescribed at the Los Angeles LGBT Center between March 2010 and July 2014. Fisher exact tests and logistic regressions were used to determine characteristics that distinguished nPEP seroconverters from non-seroconverters. RESULTS: Of the nPEP courses administered, 1744 had a follow-up visit for HIV testing within 24 weeks of exposure and 17 individuals seroconverted. Seven reported a known re-exposure, 8 self-reported only condom-protected sex subsequent to the initial exposure, and 2 reported abstinence since the exposure. In multivariable analyses, seroconverters were more likely than non-seroconverters to report methamphetamine use, incomplete medication adherence, and nPEP initiation later in the 72-hour window. CONCLUSIONS: Nonoccupational postexposure prophylaxis is an important emergency tool for HIV prevention. Our findings corroborate that timing of the initial nPEP dose is an important predictor of seroconversion. Although the current study did not offer the initial nPEP dose at the beginning of the visit, use of this fast-track dosing schedule will ensure that the first dose is taken as early as possible postexposure and may lower the likelihood for seroconversion. Furthermore, we recommend systematic screening for substance use because these individuals may be well suited for pre-exposure prophylaxis given their sustained risk.

The promise and pitfalls of long-acting injectable agents for HIV prevention.

PURPOSE OF REVIEW: Preexposure prophylaxis for HIV prevention is highly effective when taken as prescribed. Adherence to required dosing regimens for protection may pose challenges. Long-acting agents for HIV prevention may have the potential to improve adherence via favorable pharmacokinetics supportive of infrequent dosing. This review focuses on the potential benefits and considerations for the study and use of 2 long-acting injectable agents, cabotegravir (GSK1265744LA, CAB LA) and rilpivirine (TMC278LA, RPV LA), for use as chemoprophylaxis for HIV prevention. RECENT FINDINGS: Oral RPV is United States Food and Drug Administration approved for HIV treatment (in combination with other antiretrovirals). Both CAB LA and RPV LA are currently in phase 2a safety/tolerability/pharmacokinetic studies in anticipation and support of future efficacy evaluation. Both agents have favorable pharmacokinetics, and use is complicated by injection site reactions. SUMMARY: Long-acting injectable formulations, if safe and well tolerated, may improve pharmacokinetic coverage of exposures to HIV infection. Complexities around safety, tolerability, and starting/stopping protocols require careful consideration.

Audio-Enhanced Tablet Computers to Assess Children's Food Frequency From Migrant Farmworker Mothers.

This study sought to improve data collection in children's food frequency surveys for non-English speaking immigrant/migrant farmworker mothers using audio-enhanced tablet computers (ATCs). We hypothesized that by using technological adaptations, we would be able to improve data capture and therefore reduce lost surveys. This Food Frequency Questionnaire (FFQ), a paper-based dietary assessment tool, was adapted for ATCs and assessed consumption of 66 food items asking 3 questions for each food item: frequency, quantity of consumption, and serving size. The tablet-based survey was audio enhanced with each question "read" to participants, accompanied by food item images, together with an embedded short instructional video. Results indicated that respondents were able to complete the 198 questions from the 66 food item FFQ on ATCs in approximately 23 minutes. Compared with paper-based FFQs, ATC-based FFQs had less missing data. Despite overall reductions in missing data by use of ATCs, respondents still appeared to have difficulty with question 2 of the FFQ. Ability to score the FFQ was dependent on what sections missing data were located. Unlike the paper-based FFQs, no ATC-based FFQs were unscored due to amount or location of missing data. An ATC-based FFQ was feasible and increased ability to score this survey on children's food patterns from migrant farmworker mothers. This adapted technology may serve as an exemplar for other non-English speaking immigrant populations.