Long-acting cabotegravir pharmacokinetics with and without oral lead-in for HIV PrEP.

Long-acting cabotegravir is approved for pre-exposure prophylaxis and combination HIV treatment, both initiated with optional short-term oral lead-in (OLI). We evaluated the impact of OLI on long-acting cabotegravir pharmacokinetics. Cabotegravir plasma concentrations were compared between HIV-positive participants initiating injections with (n = 278) or without (n = 110) OLI in phase III treatment study FLAIR and in HIV-negative participants using OLI (n = 263) in pivotal pre-exposure prophylaxis studies HPTN 083 and HPTN 084. Cabotegravir pharmacokinetic profiles were simulated in three populations (assigned-male-at-birth, 50%-assigned-female-at-birth, and assigned-female-at-birth) under three scenarios: first injection given (A) 1 or (B) 3 days after final OLI dose (OLI-injection gap) or (C) without OLI. The PK objective was 80% of participants achieving 4× in vitro protein-adjusted 90% maximal inhibitory concentration (PA-IC90) and 50% achieving 8× PA-IC90. Observed trough concentrations (Cτ) were similar with and without OLI (P > 0.3). With a 3-day OLI-injection gap, simulated pre-injection Cτ remained above PK objective. Approximately 1-2 weeks after the first injection, simulated PK profiles became nearly identical among all scenarios. Without OLI, it was predicted that 80% of participants achieve 4× PA-IC90 in 1.2, 1.8, and 2.8 days after the first injection in each population, respectively, and 50% achieve 8× PA-IC90 in 1.4, 2.1, and 3.8 days, respectively. Observed long-acting cabotegravir exposure was similar with or without OLI, supporting optional OLI use. Cabotegravir exposure was predicted to remain above PK objective for OLI-injection gaps of ≤3 days and rapidly achieve PK objective after first injection without OLI. Findings are consistent between assigned-male-at-birth and assigned-female-at-birth populations.This study is registered with ClinicalTrials.gov as NCT02720094.

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.

Cabotegravir for the prevention of HIV-1 in women: results from HPTN 084, a phase 3, randomised clinical trial.

BACKGROUND: Oral pre-exposure prophylaxis has been introduced in more than 70 countries, including many in sub-Saharan Africa, but women experience considerable barriers to daily pill-taking, such as stigma, judgement, and the fear of violence. Safe and effective long-acting agents for HIV prevention are needed for women. We aimed to evaluate the safety and efficacy of injectable cabotegravir compared with daily oral tenofovir diphosphate plus emtricitabine (TDF-FTC) for HIV prevention in HIV-uninfected women. METHODS: HPTN 084 was a phase 3, randomised, double-blind, double-dummy, active-controlled, superiority trial in 20 clinical research sites in seven countries in sub-Saharan Africa. Participants were eligible for enrolment if they were assigned female sex at birth, were aged 18-45 years, reported at least two episodes of vaginal intercourse in the previous 30 days, were at risk of HIV infection based on an HIV risk score, and agreed to use a long-acting reversible contraceptive method. Participants were randomly assigned (1:1) to either active cabotegravir with TDF-FTC placebo (cabotegravir group) or active TDF-FTC with cabotegravir placebo (TDF-FTC group). Study staff and participants were masked to study group allocation, with the exception of the site pharmacist who was responsible for study product preparation. Participants were prescribed 5 weeks of daily oral product followed by intramuscular injections every 8 weeks after an initial 4-week interval load, alongside daily oral pills. Participants who discontinued injections were offered open-label daily TDF-FTC for 48 weeks. The primary endpoints of the study were incident HIV infection in the intention-to-treat population, and clinical and laboratory events that were grade 2 or higher in all women who had received at least one dose of study product. This study is registered with ClinicalTrials.gov, NCT03164564. FINDINGS: From Nov 27, 2017, to Nov 4, 2020, we enrolled 3224 participants (1614 in the cabotegravir group and 1610 in the TDF-FTC group). Median age was 25 years (IQR 22-30); 1755 (54·7%) of 3209 had two or more partners in the preceding month. 40 incident infections were observed over 3898 person-years (HIV incidence 1·0% [95% CI 0·73-1·40]); four in the cabotegravir group (HIV incidence 0·2 cases per 100 person-years [0·06-0·52]) and 36 in the TDF-FTC group (1·85 cases per 100 person-years [1·3-2·57]; hazard ratio 0·12 [0·05-0·31]; p<0·0001; risk difference -1·6% [-1·0% to -2·3%]. In a random subset of 405 TDF-FTC participants, 812 (42·1%) of 1929 plasma samples had tenofovir concentrations consistent with daily use. Injection coverage was 93% of the total number of person-years. Adverse event rates were similar across both groups, apart from injection site reactions, which were more frequent in the cabotegravir group than in the TDF-FTC group (577 [38·0%] of 1519 vs 162 [10·7%] of 1516]) but did not result in injection discontinuation. Confirmed pregnancy incidence was 1·3 per 100 person-years (0·9-1·7); no congenital birth anomalies were reported. INTERPRETATION: Although both products for HIV prevention were generally safe, well tolerated, and effective, cabotegravir was superior to TDF-FTC in preventing HIV infection in women. FUNDING: National Institute of Allergy and Infectious Diseases, ViiV Healthcare, and the Bill & Melinda Gates Foundation. Additional support was provided through the National Institute of Mental Health, the National Institute on Drug Abuse, and the Eunice Kennedy Shriver National Institute of Child Health and Human Development. ViiV Healthcare and Gilead Sciences provided pharmaceutical support.

"It's already in your body and it's preventing": a qualitative study of African female adolescent's acceptability and preferences for proxy HIV prevention methods in Cape Town, South Africa.

BACKGROUND: Advances in biomedical HIV prevention will soon offer young women a choice of HIV prevention methods, including various pre-exposure prophylaxis (PrEP) modalities such as daily oral pills, dapivirine vaginal ring, and long-acting injectable agents. By understanding preferences for contraceptive methods, we may draw analogies for the HIV prevention needs of young women. The UChoose Study was an open-label randomised cross-over study designed to evaluate the acceptability and preference for several contraceptive options as a proxy for HIV prevention methods that use similar types of administration. The study enrolled healthy HIV uninfected young women aged 15 to 19 years. At enrolment, participants were randomly assigned to a contraceptive method for a period of 16 weeks in the form of monthly Nuvaring® (vaginal ring), daily combined oral contraceptive (daily pills), or bi-monthly injectable contraceptive (injectable). After 16 weeks, participants crossed over to another contraceptive method, and those who had received the injectable and the daily pills received the vaginal ring for another 16 weeks, whereas those who had received the vaginal ring were able to choose between the injectable and daily pills, to ensure that all participants tried the vaginal ring-the least familiar option to the study population. RESULTS: Thirty-three participants were purposively recruited to participate in seven focus group discussions (FGD) and completed a pre-survey for their assigned group. Our sample comprised 14 participants randomised to use of the vaginal ring and daily pills and 19 participants randomised to use of the vaginal ring and injectable. For most participants, their preferences for a prevention method were based primarily on their desire to avoid negative aspects of one method rather than their positive user experience with another method. Most participants expressed initial hesitancy for trying new contraception method products; however, a lack of familiarity was moderated by a strong interest in diverse user-controlled prevention methods. Participants valued methods that had infrequent dosing and simplified use requirements. The injection and vaginal ring were preferred over daily pills as a potential HIV prevention method. CONCLUSION: Expanding the availability of diverse products could provide adolescents with multiple choices in HIV prevention for the uninitiated. TRIAL REGISTRATION: ClinicalTrials.gov ( NCT02404038 ). Registered March 31, 2015-Registered.

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.

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.

Sexual behavior and medication adherence in men who have sex with men participating in a pre-exposure prophylaxis study of combinations of Maraviroc, Tenofovir Disoproxil Fumarate and/or Emtricitabine (HPTN 069/ACTG 5305).

HPTN 069/ACTG 5305 was designed to evaluate potential new PrEP regimens that included maraviroc, tenofovir disoproxil fumarate, and/or emtricitabine. The current analyses assessed antiretroviral (ARV) plasma concentrations in relation to sexual behavior in 224 cisgender men who have sex with men and 2 transgender women at risk for HIV. Poisson generalized estimating equations (GEE) regression were used to test for associations between self-reported sexual behavior, sociodemographic, behavioral variables, and study drug levels The median (IQR) age was 30 [25, 37] years old; 48.2% had completed college; 27.4% were Black and 21.7% Latino. At weeks 24 and 48, one third of participants reported condomless anal sex (CAS) in the prior month with more than one partner. CAS was associated with daily ARV drug use (χ2 = 12.64, p = 0.002). Older individuals and those with greater education were more likely to ingest ARV drugs daily (χ2 = 9.36, p = 0.009 and χ2 = 8.63, p = 0.013, respectively), while neither race nor ethnicity was associated with daily ARV drug use. Participants who reported recent condomless anal sex and/or advanced education had higher rates of daily ARV drug use. These data support the need for ongoing adherence counseling in clinical trials of new PrEP modalities.

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.

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.

Acceptability of Long-Acting Injectable Cabotegravir (CAB LA) in HIV-Uninfected Individuals: HPTN 077.

Long-acting injectable PrEP could offer an alternative to daily oral PrEP, improve adherence and protection, if found acceptable, safe and effective. HPTN 077 evaluated injectable cabotegravir safety, tolerability and pharmacokinetics among HIV-uninfected males and females in sequentially-enrolled cohorts of two dosing strategies. We compared acceptability of product attributes, prevention preferences and future interest in injectable PrEP (FIIP) by region, sex-at-birth, arm and cohort and used multivariable analysis to identify FIIP determinants. Baseline injectable PrEP preferences were higher in non-U.S. sites and increased in both regions over time. In multivariable models, FIIP was most strongly associated with acceptability of product attributes, was higher in non-U.S. sites and more altruistic participants. Treatment arm and report of pain were not associated with FIIP. Injectable acceptability was highest in non-U.S. sites. Preferences for injectable versus other PrEP methods were higher among U.S. males than females, but higher among males and females in non-U.S. settings.

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.

Safety and Tolerability of Maraviroc-Containing Regimens to Prevent HIV Infection in Women: A Phase 2 Randomized Trial.

BACKGROUND: Maraviroc (MVC) is a candidate drug for HIV preexposure prophylaxis (PrEP). OBJECTIVE: To assess the safety and tolerability of MVC-containing PrEP over 48 weeks in U.S. women at risk for HIV infection. DESIGN: Phase 2 randomized, controlled, double-blinded study of 4 antiretroviral regimens used as PrEP. (ClinicalTrials.gov: NCT01505114). SETTING: 12 clinical research sites of the HIV Prevention Trials Network and AIDS Clinical Trials Group. PARTICIPANTS: HIV-uninfected women reporting condomless vaginal or anal intercourse with at least 1 man with HIV infection or unknown serostatus within 90 days. INTERVENTION: MVC only, MVC-emtricitabine (FTC), MVC-tenofovir disoproxil fumarate (TDF), and TDF-FTC (control). MEASUREMENTS: At each visit, clinical and laboratory (including HIV) assessments were done. Primary outcomes were grade 3 and 4 adverse events and time to permanent discontinuation of the study regimen. All randomly assigned participants were analyzed according to their original assignment. RESULTS: Among 188 participants, 85% completed follow-up, 11% withdrew early, and 4% were lost to follow-up; 19% discontinued their regimen prematurely. The number discontinuing and the time to discontinuation did not differ among regimens. Grade 3 or 4 adverse events occurred in 5 (MVC), 13 (MVC-FTC), 9 (MVC-TDF), and 8 (TDF-FTC) participants; rates did not differ among regimens. One death (by suicide) occurred in the MVC-TDF group but was judged not to be related to study drugs. Of available plasma samples at week 48 (n = 126), 60% showed detectable drug concentrations. No new HIV infections occurred. LIMITATIONS: Participants were not necessarily at high risk for HIV infection. The regimen comprised 3 pills taken daily. The study was not powered for efficacy. CONCLUSION: Maraviroc-containing PrEP regimens were safe and well-tolerated compared with TDF-FTC in U.S. women. No new HIV infections occurred, although whether this was due to study drugs or low risk in the population is uncertain. Maraviroc-containing PrEP for women may warrant further study. PRIMARY FUNDING SOURCE: National Institutes of Health.

Phase 2 Study of the Safety and Tolerability of Maraviroc-Containing Regimens to Prevent HIV Infection in Men Who Have Sex With Men (HPTN 069/ACTG A5305).

BACKGROUND: Maraviroc (MVC) is a candidate for human immunodeficiency virus (HIV) pre-exposure prophylaxis. METHODS: Phase 2 48-week safety/tolerability study was conducted, comparing 4 regimens: MVC alone, MVC plus emtricitabine (FTC), MVC plus tenofovir disoproxil fumarate (TDF), and TDF plus FTC. Eligible participants were HIV-uninfected men and transgender women reporting condomless anal intercourse with ≥1 HIV-infected or unknown-serostatus man within 90 days. At each visit, assessments, laboratory testing, and counseling were done. Analyses were intention to treat. RESULTS: Among 406 participants, 84% completed follow-up, 7% stopped early, and 9% were lost to follow-up; 9% discontinued their regimen early. The number discontinuing and the time to discontinuation did not differ among study regimens (P = .60). Rates of grade 3-4 adverse events did not differ among regimens (P = .37). In a randomly selected subset, 77% demonstrated detectable drug concentrations at week 48. Five participants acquired HIV infection (4 MVC alone, 1 MVC + TDF; overall annualized incidence, 1.4% [95% confidence interval, .5%-3.3%], without differences by regimen; P = .32); 2 had undetectable drug concentrations at every visit, 2 had low concentrations at the seroconversion visit, and 1 had variable concentrations. CONCLUSIONS: MVC-containing regimens were safe and well tolerated compared with TDF + FTC; this study was not powered for efficacy. Among those acquiring HIV infection, drug concentrations were absent, low, or variable. MVC-containing regimens may warrant further study for pre-exposure prophylaxis. CLINICAL TRIALS REGISTRATION: NCT01505114.

African Tick Bite Fever Treated Successfully With Rifampin in a Patient With Doxycycline Intolerance.

African tick bite fever is the most commonly encountered travel-associated rickettsiosis, occurring in as many as 5% of travelers returning from rural subequatorial Africa. This case report illustrates that rifampin represents an effective alternative to doxycycline for treatment of African tick bite fever in some selective situations.

Sustaining aquifers hydrologically, economically, and institutionally: Policy analysis of the Ogallala in New Mexico.

Groundwater discharge exceeding recharge threatens sustainable aquifer water use internationally. Interest remains high in discovering more hydrologically sustainable and economically affordable measures to protect these aquifers. Previous research has conducted various aquifer assessments. Some work has investigated costs and benefits of various plans that would limit aquifer pumping. Despite notable advances in this kind of analysis, little published work to date has unified these elements into a science-based integrated framework to inform more sustainable aquifer policy design. This work's novel contribution is to integrate analysis of hydrology, economics, institutions, and policy into a unified scientific framework to inform choices on more sustainable pumping strategies while protecting economic activity for agricultural and urban water-using sectors. It does so by conceptualizing, formulating, designing, and applying a mathematical programming framework to replicate historically observed pumping patterns in parts of the Southern and Central High Plains Ogallala Aquifer region in New Mexico, USA. We first calibrated the optimization framework to replicate the historically observed data. We then go on to identify least cost pumping caps that would have partly restored the aquifer to its 2014 level by 2020, while comparing the performance of four other partial aquifer protection policy measures. Findings indicate a surprisingly low cost that could have been incurred to partially protect the aquifer over that period. However, these low costs are complicated by (1) decreasing water quality outside of the irrigated regions and (2) focusing of lateral inputs to a narrower zone of depression around the irrigated regions. These findings carry important implications for identifying more sustainable aquifer management plans internationally. The work's importance comes from its capacity to inform policy debates over a range of water shortage sharing plans, while respecting institutional constraints governing equitable burden sharing.

Willingness and preferences for long-acting injectable PrEP among US men who have sex with men: a discrete choice experiment.

INTRODUCTION: Cabotegravir long-acting injectable HIV pre-exposure prophylaxis (LA-PrEP) was shown to be safe and effective in multiple clinical trials. Increasing uptake and persistence among populations with elevated risk for HIV acquisition, especially among men who have sex with men (MSM), is critical to HIV prevention. OBJECTIVE: This analysis aims to understand potential users' preferences for LA-PrEP, with audience segmentation. DESIGN: Willingness to use and preferences for LA-PrEP were measured in HIV-negative, sexually active MSM in the 2020 American Men's Internet Survey. Respondents answered a discrete choice experiment with paired profiles of hypothetical LA-PrEP characteristics with an opt-out option (no LA-PrEP). Conditional and mixed logit models were run; the final model was a dummy-coded mixed logit that interacted with the opt-out. SETTING: US national online sample. RESULTS: Among 2506 MSM respondents, most (75%) indicated a willingness to use LA-PrEP versus daily oral PrEP versus no PrEP. Respondents were averse to side effects and increasing costs and preferred increasing levels of protection. Respondents preferred a 2-hour time to obtain LA-PrEP vs 1 hour, with a strong aversion to 3 hours. Overall, there was an aversion to opting out of LA-PrEP, with variations: those with only one partner, no/other insurance or who were Black, Indigenous or People of Colour were significantly less likely to prefer LA-PrEP, while those who were Hispanic/Latino, college educated and <40 years significantly preferred LA-PrEP. CONCLUSIONS: A large proportion of MSM expressed a preference for LA-PrEP over daily oral pills. Most respondents chose LA-PrEP regardless of cost, clinic time, side effects or protection level; however, preferences varied by sociodemographics. These varied groups likely require tailored intervention strategies to achieve maximum LA-PrEP uptake and persistence.

Evaluation of Xpert point-of-care assays for detection of HIV infection in persons using long-acting cabotegravir for pre-exposure prophylaxis.

Detection of HIV infection may be challenging in persons using long-acting cabotegravir (CAB-LA) pre-exposure prophylaxis (PrEP) due to viral suppression and reduced/delayed antibody production. We evaluated two point-of-care tests for detecting HIV infection in persons who received CAB-LA in the HPTN 083 trial. Samples were obtained from 12 participants who received CAB-LA and had delayed detection of HIV infection using HIV rapid tests and an antigen/antibody test (52 plasma samples; 18 dried blood spot [DBS] samples). Plasma samples were tested with the Xpert HIV-1 Viral Load XC test (Xpert VL-XC); DBS samples were tested with the total nucleic acid Xpert HIV-1 Qual XC test (Xpert Qual-XC). Results from these assays were compared to results from three reference, laboratory-based, plasma RNA assays (Aptima HIV-1 Qualitative assay [Aptima Qual]; Aptima HIV-1 Quant DX Assay [Aptima Quant]; cobas HIV-1/HIV-2 Qualitative Test [cobas]). HIV RNA was detected with all four plasma assays for all samples with viral loads (VLs) ≥ 200 copies/mL; the number of samples with VLs < 200 copies/mL with HIV RNA detected was: Xpert VL-XC: 19/26 (73.1%); Aptima Qual: 17/26 (65.4%); Aptima Quant: 17/26 (65.4%); and cobas: 12/21 (57.1%). The Xpert Qual-XC assay was positive for all DBS samples with VLs ≥ 200 copies/mL and 1/10 DBS with VLs < 200 copies/mL. The performance of the Xpert VL-XC assay was comparable to the reference assays for detecting HIV infection in these cases. The Xpert Qual-XC assay was less sensitive than plasma-based HIV RNA assays for detecting HIV in the setting of CAB-LA PrEP. IMPORTANCE: HIV RNA assays can detect HIV infections earlier than HIV rapid tests or Ag/Ab tests in persons using CAB-LA PrEP. Earlier HIV diagnosis could allow for earlier treatment initiation and reduced risk of INSTI resistance. POC tests may help detect HIV infection before CAB-LA administration and may be more accessible than laboratory-based assays in some settings. In this study, the POC Xpert VL-XC assay detected HIV RNA in most samples from individuals who received CAB-LA PrEP and had delayed detection of HIV infection with HIV rapid tests and an Ag/Ab test. The performance of this assay was similar to laboratory-based HIV RNA assays in this cohort. The POC Xpert Qual-XC assay detects both HIV RNA and DNA, with a higher viral load cutoff for RNA detection. This assay was negative for most lower viral load samples and did not offer an advantage for HIV screening in persons using CAB-LA PrEP.

HPTN 083-02: factors influencing adherence to injectable PrEP and retention in an injectable PrEP study.

INTRODUCTION: HPTN 083 demonstrated the superiority of long-acting cabotegravir (CAB-LA) versus daily oral emtricitabine/tenofovir disoproxil fumarate (TDF/FTC) as pre-exposure prophylaxis (PrEP) among cisgender men and transgender women who have sex with men (MSM/TGW). HPTN 083 provided the first opportunity to understand experiences with injectable PrEP in a clinical trial. METHODS: Participants from two US sites (Chicago, IL and Atlanta, GA) and one international site (Rio de Janeiro, Brazil) were purposively sampled for individual qualitative interviews (N = 40), between November 2019 and March 2020, to explore trial experiences, barriers to adherence and other factors that may have impacted study implementation or outcomes. The blinded phase ended early due to efficacy; this analysis includes interviews conducted prior to unblinding with three groups defined by adherence (i.e. injection visit attendance): adherent (n = 27), non-adherent (n = 12) and early discontinuers (n = 1). Data were organized using NVivo software and analysed using content analysis. RESULTS: Participants (mean age: 27) were primarily cisgender MSM (90%) and Black/African American (60%). Reasons for trial enrolment and PrEP use included a preference for using HIV prevention medication versus treatment in the event of HIV acquisition; the ability to enhance health via study-related education and services; access to a novel, convenient HIV prevention product at no cost; and contributing to MSM/TGW communities through research. Participants contrasted positive experiences with study staff with their routine clinical care, and emphasized increased scheduling flexibility, thorough communication, non-judgemental counselling and open, affirming environments (e.g. compassion, less stigma) as adherence facilitators. Injection experiences were positive overall; some described early injection-related anxiety, which abated with time and when given some measure of control (e.g. pre-injection countdown), and minimal injection site discomfort. Some concerns and misperceptions about injectable PrEP were reported. Barriers to adherence, across all adherence categories, included structural factors (e.g. financial constraints, travel) and competing demands (e.g. work schedules). CONCLUSIONS: Respondents viewed injectable PrEP trial participation as a positive experience and a means of enhancing wellbeing. Study site flexibility and affirming clinic environments, inclusive of non-judgemental counselling, were key facilitators of adherence. To support injection persistence, interventions that address structural barriers and promote flexible means of injection delivery may be most effective.

Variation in Preferences for Long-Acting Injectable Pre-Exposure Prophylaxis Among US Men Who Have Sex with Men: A Latent Class Analysis.

Cabotegravir long-acting injectable HIV pre-exposure prophylaxis (LA PrEP) is efficacious, with a good safety profile, and was approved by the US Food and Drug Administration in December 2021. Understanding variations in potential user preferences for LA PrEP may inform implementation and subsequently improve uptake and community-level effectiveness. HIV-negative, sexually active men who have sex with men (MSM) aged ≥15 years were recruited online for the 2019 American Men's Internet Survey, before LA PrEP approval. Respondents completed a discrete-choice experiment (DCE) with hypothetical LA PrEP attributes (out-of-pocket cost, perceived side effects, injection frequency, perceived stigma, service location). Latent class analysis segmented respondents into groups based on their preferences for the attributes presented, and relative importance of preference weights and willingness-to-pay were calculated. While the majority had never used daily oral PrEP, 73% of the 2489 respondents were very or somewhat likely to use LA PrEP. Three latent classes were identified from 2241 respondents in the DCE. The "side effects-averse" class was the largest group (64% of respondents) and placed 61% relative importance on side effects. The "ambivalent" class (20% of respondents) placed higher importance on stigma (17% of relative importance) than other classes. The "cost-conscious" class (16% of respondents) placed higher relative importance (62%) on cost compared with other attributes and classes. Perceived side effects were an important hypothetical barrier for LA PrEP uptake among a large proportion of potential MSM users. Minimizing out-of-pocket costs is likely to increase uptake and may be important to equitable access. Tailored communication strategies are recommended for the different groups of potential LA PrEP users.