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

Willingness to Use Oral and Long-Acting Injectable PrEP in Substance-Using Men who have Sex with Men (SU-MSM) in High HIV Incidence Southern U.S. Cities: A NIDA Clinical Trials Network Study

In Southern U.S. states with high HIV incidence and low HIV Pre-Exposure Prophylaxis (PrEP) uptake, enhanced efforts to increase interest in and willingness to use PrEP are needed. This implementation survey examined the associations of sociodemographic background, substance use, and sexual risk behaviors with willingness to use daily oral and long-acting injectable (LAI) PrEP among substance using men who have sex with men (SU-MSM). Participants were 225 SU-MSM recruited from sexually transmitted infection (STI) clinics, syringe services programs (SSPs), and substance use treatment programs (SUTPs) in eight Southern U.S. cities. Rates of willingness were high for both daily oral PrEP (78%) and LAI PrEP (66%). In multivariable analyses, distinct factors were associated with willingness towards each. For daily oral PrEP, greater willingness was associated with condomless anal sex, less frequent non-injection opioid use, prior PrEP awareness, and past use of PrEP. For LAI PrEP, greater willingness was associated with Black race, identifying as gay, being single, and higher injection drug use frequency. Lower willingness to use LAI PrEP was associated with higher non-injection opioid use frequency. Findings about willingness to use LAI PrEP, as a relatively newer modality, and greater willingness among Black SU-MSM as a disproportionately HIV-impacted population, are especially important. These findings argue for the necessity to enhance PrEP promotion efforts that distinguish between oral and LAI PrEP and that are specifically tailored to major SU-MSM subgroups in the Southern U.S.

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

BACKGROUND

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

METHODS

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

FINDINGS

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

INTERPRETATION

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

FUNDING

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

High Preference for Injectable Pre-exposure Prophylaxis among Young Women in Kenya

Longer acting HIV pre-exposure prophylaxis (PrEP) products are effective options for HIV prevention that require less user-dependence. As programs are preparing to launch delivery of these longer acting products, it is important to understand users' needs and preferences. We conducted a cross-sectional study among women seeking services at 12 family planning clinics in Kisumu, Kenya. Participants were sexually active HIV-negative women ≥15 years, with at least one characteristic that is more common among women who acquire HIV. We assessed PrEP product preferences among PrEP-experienced and inexperienced women. We used descriptive statistics to summarize participants' characteristics, product preferences, and willingness to use different PrEP modalities. We used univariate and multivariate models to assess factors related to preferences for injectable PrEP. A total of 457 participants were enrolled, including 341 with no oral PrEP experience and 116 with recent oral PrEP experience. The median age was 26 [IQR:23-30], 83% were married or cohabiting and 31% reported using injectable contraceptives. Among participants without prior PrEP experience, 74% preferred injectable PrEP, 19% preferred oral PrEP, and 4% preferred the vaginal ring. Among previous oral PrEP users, 82% preferred injectable PrEP, 16% preferred oral PrEP, and only 2% preferred the dapivirine vaginal ring. Only perceived PrEP stigma was significantly associated with injectable PrEP preference (PR: 1.21, 95% CI 1.09, 1.37, P=0.001). Reproductive-age women in Kenya have a strong interest in long-acting injectable PrEP. Product rollout and implementation needs to consider women's preference and devise best approaches to deliver injectable PrEP.

Cost thresholds for anticipated long-acting HIV pre-exposure prophylaxis products in Eastern and Southern Africa: a mathematical modelling study

INTRODUCTION

Affordable HIV prevention tools are needed in Eastern and Southern Africa (ESA). Several promising long-acting pre-exposure prophylaxis (LA-PrEP) products are available or in development. However, ESA settings face severe healthcare resource constraints. We aimed to estimate the threshold price at which LA-PrEP products could be cost-effective in three ESA settings.

METHODS

We adapted an agent-based model, EMOD-HIV, to simulate LA-PrEP (monthly oral, 2- and 6-monthly injectable) rollout in South Africa, Zimbabwe and Kenya. Due to uncertainties about LA-PrEP use, we examined a range of coverages (5%-20% of HIV-negative sexually active adults) and extents to which LA-PrEP use will be concentrated among those most at risk (prioritized rollout from higher- to lower-risk groups vs. uniform rollout among sexually active adults). To evaluate a 20-year commitment to LA-PrEP delivery, we assumed LA-PrEP was scaled up to target coverage from 2025 to 2030 and maintained at target levels before ending in 2045. We estimated maximum per-dose and per-year LA-PrEP costs that achieve cost-effectiveness (

RESULTS

Risk-prioritized LA-PrEP for 5% of adults was projected to avert 11-21% of HIV acquisitions across settings, with 3-5 times more HIV acquisitions averted and 3-5 times higher maximum cost compared to non-prioritized rollout. Six-monthly injectable PrEP supported the highest per-dose cost: in the scenario with the most cost-effective LA-PrEP use (5% risk-prioritized rollout), the maximum per-dose price in South Africa was $52.99 (95% CI: $48.82-$57.21), in Zimbabwe $14.64 (95% CI: $12.04-$17.38) and in western Kenya $7.50 (95% CI: $6.73-$8.27). For monthly oral PrEP, corresponding per-dose costs were $5.02 (95% CI: $4.67-$5.37), $1.45 (95% CI: $1.10-$1.79) and $0.87 (95% CI: $0.80-$0.93). Results were sensitive to eligible population and prioritization, and moderately sensitive to scale-up speed and product effectiveness.

CONCLUSIONS

LA-PrEP is likely to require reduced pricing and/or risk-prioritized rollout to be cost-effective in ESA.

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Key Words

• Africa
• HIV
• lenacapavir
• long‐acting
• modelling
• pre‐exposure prophylaxis

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MESH Headings

• Pre-Exposure Prophylaxis/economics
• Pre-Exposure Prophylaxis/methods
• Humans
• HIV Infections/prevention & control
• HIV Infections/economics
• Cost-Benefit Analysis
• Africa, Southern/epidemiology
• Anti-HIV Agents/economics
• Anti-HIV Agents/administration & dosage
• Female
• Adult
• Male
• Models, Theoretical
• Africa, Eastern
• Kenya

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Grants

• R01 AI179417 NIAID NIH HHS
• R01AI179417 US National Institutes of Health
• INV-038274 Bill & Melinda Gates Foundation
• Children's Investment Foundation Fund (CIFF)

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Affiliation(s)

David Kaftan Department of Population HealthNew York University Grossman School of MedicineNew YorkNew York10016USA
Monisha Sharma Department of Global HealthUniversity of WashingtonSeattleWashingtonUSA
Danielle Resar Clinton Health Access InitiativeBostonMassachusettsUSA
Masabho Milali Department of Population HealthNew York University Grossman School of MedicineNew YorkNew York10016USA
Edinah Mudimu University of South AfricaPretoriaSouth Africa
Linxuan Wu Department of Global HealthUniversity of WashingtonSeattleWashingtonUSA
Cory Arrouzet Department of Global HealthUniversity of WashingtonSeattleWashingtonUSA
Ingrida Platais Department of Population HealthNew York University Grossman School of MedicineNew YorkNew York10016USA
Hae‐Young Kim Department of Population HealthNew York University Grossman School of MedicineNew YorkNew York10016USA
Sarah Jenkins Clinton Health Access InitiativeBostonMassachusettsUSA
Anna Bershteyn Department of Population HealthNew York University Grossman School of MedicineNew YorkNew York10016USA

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Comparative Analyses of Antiviral Potencies of Second-Generation Integrase Strand Transfer Inhibitors (INSTIs) and the Developmental Compound 4d Against a Panel of Integrase Quadruple Mutants

Second-generation integrase strand transfer inhibitors (INSTIs) are strongly recommended for people living with HIV-1 (PLWH). The emergence of resistance to second-generation INSTIs has been infrequent and has not yet been a major issue in high-income countries. However, the delayed rollouts of these INSTIs in low- to middle-income countries during the COVID-19 pandemic combined with increased transmission of drug-resistant mutants worldwide are leading to an increase in INSTI resistance. Herein, we evaluated the antiviral potencies of our lead developmental INSTI 4d and the second-generation INSTIs dolutegravir (DTG), bictegravir (BIC), and cabotegravir (CAB) against a panel of IN quadruple mutants. The mutations are centered around G140S/Q148H, including positions L74, E92, and T97 combined with E138A/K/G140S/Q148H. All of the tested INSTIs lose potency against these IN quadruple mutants compared with the wild-type IN. In single-round infection assays, compound 4d retained higher antiviral potencies (EC50 values) than second-generation INSTIs against a subset of quadruple mutants. These findings may advance understanding of mechanisms that contribute to resistance and, in so doing, facilitate development of new INSTIs with improved antiviral profiles.

Expanding Treatment Opportunities: Reviewing the Current State of Injectable Antiretrovirals for Treatment of HIV

Antiretroviral therapy has evolved significantly over the last 20-30 years, from requiring multiple tablets multiple times per day to single-tablet regimens and most recently, in 2021, long-acting injectable antiretrovirals. These long-acting antiretrovirals have expanded the treatment options for individuals with HIV who may have difficulty adhering to daily oral medications, difficulty taking oral medications, and/or individuals with multidrug-resistant HIV. This article reviews the currently available long-acting injectable antiretrovirals, including cabotegravir/rilpivirine, lenacapavir, and ibalizumab. The available data supporting these agents and current place in therapy will be discussed. Data supporting the use of additional long-acting injectable agents, broadly neutralizing antibodies, currently in the pipeline will be reviewed as well.

Pharmacologic evaluation of delayed long-acting cabotegravir administration among cisgender women in HPTN 084

HPTN 084 demonstrated the superiority of long-acting injectable cabotegravir (CAB-LA) compared with daily oral tenofovir disoproxil fumarate-emtricitabine (F/TDF) for HIV prevention in women. CAB-LA (600 mg) or placebo injections were administered 4 weeks after an initial dose (loading dose) and every 2 months (Q2M) thereafter; this is the approved regimen. Participants experienced both loading dose and Q2M delays during the trial. CAB concentrations were evaluated before a delay, at the visit associated with the delay, and the visit after a delayed injection was administered. During the blinded phase of the trial, 194 participants randomized to CAB-LA experienced at least one injection delay. Plasma CAB concentrations were maintained above the 4× protein adjusted 90% inhibitory concentration (4× PA-IC90; protocol-specific threshold) for all loading dose and 98% of Q2M delays when injections were administered up to 6 weeks late. The feasibility of shifting to an every 3-month (Q3M) regimen in females was interrogated via simulation studies using a population pharmacokinetic model. Q3M injections in both CAB-naïve (with a loading dose) and previously CAB-exposed females were predicted to yield higher steady-state exposures than in males on the approved Q2M regimen. Although there is observed forgiveness following an isolated delayed CAB-LA injection and simulations suggest acceptable CAB-LA exposures in women with a 600 mg CAB-LA Q3M regimen, empirical efficacy of this regimen has not been established, and transitioning to this dosing schema is not recommended. Future pharmacokinetic bridging studies are aimed at evaluating higher dose CAB-LA formulations administered less frequently.

CLINICAL TRIALS

This study is registered with ClinicalTrials.gov as NCT03164564.

Related barriers to using HIV pre-exposure prophylaxis among MSM: A multicentre cross-sectional survey

OBJECTIVE

The objective of this study was to gain insight into the barriers hindering the use of pre-exposure prophylaxis (PrEP) among men who have sex with men (MSM) in five cities in China.

METHODS

MSM were recruited via community-based organizations in an online "snowball" manner. Participants completed the questionnaire anonymously and shared it with key MSM peers (seeds) in five cities in China. Based on the results of univariate analysis, we used a structural equation model to analyse the role of PrEP knowledge awareness, PrEP counselling, and other behavioural variables on PrEP use.

RESULTS

The study collected a total of 4223 valid questionnaires, and 18.2% of participants reported PrEP use. The results of the standardized total effects showed that the following paths were statistically significant (p < 0.05): from the age of first sex with men to PrEP knowledge awareness (β = -0.113) and PrEP use (β = 0.042); from high-risk sexual behaviour scores to PrEP counselling (β = 0.039) and PrEP use (β = 0.103); from the number of HIV tests in the last year to PrEP knowledge awareness (β = 0.034), PrEP counselling (β = 0.170), and PrEP use (β = 0.197); from the level of self-perceived risk of HIV infection to PrEP counselling (β = -0.115); from PrEP knowledge awareness to PrEP use (β = -0.049); and from PrEP counselling to PrEP use (β = 0.420).

CONCLUSIONS

The proportion of PrEP use among MSM was relatively low. Age at first sex with men, number of HIV tests, high-risk sexual behaviour, and PrEP counselling had a positive effect on PrEP use, whereas PrEP knowledge awareness had an inverse effect on PrEP use.

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

BACKGROUND

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

METHODS

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

FINDINGS

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

INTERPRETATION

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

FUNDING

Gilead Sciences.

Peer Influence on Motivation to Use Pre-Exposure Prophylaxis Among Latino Sexual Minority Men in Miami, Florida: A Network Autocorrelation Model

Despite the availability of pre-exposure prophylaxis (PrEP), Latino sexual minority men (LSMM) continue to experience disparities in PrEP uptake and subsequently, HIV vulnerability. Social network norms are an underutilized solution to increase PrEP uptake. We used a peer influence model (network autocorrelation model) to examine the role of social network descriptive norms (i.e., actual behaviors) surrounding PrEP use. A total of 11 sociocentric networks of 13 friends (n = 143 LSMM) were recruited into our study from 2018 to 2019 in South Florida. Most participants were in PrEP pre-contemplation (n = 44), and almost one-third of our sample were using PrEP (n = 38). Three network autocorrelation models were estimated using an empirically informed Bayesian analysis. We found a positive association between participants' Motivational PrEP Cascade (MPC) position and their network members' (friends') cascade position based on three different measures of connection even when accounting for PrEP knowledge: friendship (ρ = 0.22; 95% CIa = 0.01-0.42), emotional closeness (ρ = 0.24; 95% CI = 0.03-0.44), and frequency of interaction (ρ = 0.22; CI = 0.03-0.42). Our findings highlight that an individual's progress in the MPC may be influenced by their network members' progress in the MPC, suggesting that LSMM using PrEP may serve as role models to their peers for PrEP use due to descriptive norms. Our findings further suggest that PrEP interventions for LSMM along the MPC can be implemented at the social network level.

Low cabotegravir trough concentrations without oral lead-in in patients with HIV-1 switching to long-acting cabotegravir and rilpivirine

In a cohort of 72 consecutive virologically-suppressed patients with HIV-1 switching to long-acting cabotegravir and rilpivirine, we observed low cabotegravir trough concentrations 1 and 3 months after the first injection, with a significant association with no oral lead-in at 1 month [odds ratio (OR) = 6.3 [95% confidence interval (CI) 1.7-29.5], P = 0.01] and three months (OR = 5.6 [95% CI 1.3-29.7], P = 0.03), and with high BMI at 1 month (OR = 1.3 [95% CI 1.1-1.6], P = 0.007).

"I Feel Like I Don't Even Have HIV Anymore"-Facilitators, Barriers, and Experience regarding Use of Long-Acting Injectable Antiretroviral Therapy Among Persons with HIV in North Carolina

As access to long-acting injectable antiretroviral therapy (LAI ART) expands, understanding patient perceptions and experiences around LAI should inform equitable scale-up and effective implementation strategies. This study used qualitative research design relying on semi-structured interviews conducted among persons with HIV (PWH) who were either virally suppressed on oral treatment (n = 11) or had received at least one dose of injectables (n = 7). Approximately half of participants identified as male (10/18) and most identified as African American (17/18). Among participants on oral ART, many described the prospect of injectable treatment as likely convenient and discreet, relieving the stress of remembering to take daily pill. Nearly all had heard of LAI ART prior to the interview, often from television or internet commercials. Most were excited about less frequent dosing, though expressed concern about the logistics involved in coming to clinic every two months. Many expressed uncertainties regarding the relative effectiveness of LAI ART compared with oral therapy and were wary of potential pain related to injections. In contrast, all persons on LAI ART described injection-site soreness as manageable. In addition to acknowledging the convenience of every-two-month injections, some persons receiving LAI ART expressed relief by lifting the emotional stress of taking a daily-pill that reminded them of their HIV positive status. Emerging clinical trial data supports the individual and public health benefits of LAI ART, regardless of prior viral-suppression; our work adds to a growing body of literature demonstrating the potential psychological benefits associated with this novel treatment modality for PWH regardless of recent viral-suppression.

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.

CLINICAL TRIALS

This study is registered with ClinicalTrials.gov as NCT02720094.

Fluorine in the pharmaceutical industry: Synthetic approaches and application of clinically approved fluorine-enriched anti-infectious medications

The strategic integration of fluorine atoms into anti-infectious agents has become a cornerstone in the field of medicinal chemistry, owing to the unique influence of fluorine on the chemical and biological properties of pharmaceuticals. This review examines the synthetic methodologies that enable the incorporation of fluorine into anti-infectious drugs, and the resultant clinical applications of these fluorine-enriched compounds. With a focus on clinically approved medications, the discussion extends to the molecular mechanisms. It further outlines the specific effects of fluorination, which contribute to the heightened efficacy of anti-infective therapies. By presenting a comprehensive analysis of current drugs and their developmental pathways, this review underscores the continuing evolution and significance of fluorine in advancing anti-infectious treatment options. The insights offered extend valuable guidance for future drug design and the development of next-generation anti-infectious agents.

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.

Challenges, risks, and opportunities of antiretroviral drugs in women of reproductive potential

INTRODUCTION

The HIV/AIDS epidemic has been one of the greatest challenges in global health, significantly affecting women of reproductive potential. Considerable advances in antiretroviral therapy for women living with HIV have contributed to improvements in quality of life, better reproductive and birth outcomes, and a reduced risk of perinatal transmission.

AREAS COVERED

Despite the progress made, persistent challenges in access and adherence to antiretroviral drugs may limit their benefits for some women. More pharmacokinetic and safety studies in pregnant and lactating women are urgently needed, as are prospective surveillance systems to evaluate associations between fetal and infant antiretroviral exposures, drug-drug interactions, and pregnancy outcomes.

EXPERT OPINION

Multipurpose technologies, such as combined HIV and other STI or unintended pregnancy prevention, and innovative delivery methods, such as the development of long-acting antiretrovirals, have the potential to reduce adherence challenges and enhance quality of life for women with HIV. Parallel advances in drug safety testing and surveillance are needed to ensure the health and safety of women with or at risk for HIV and children at risk for perinatal transmission.

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

OBJECTIVES

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

DESIGN/METHODS

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

RESULTS

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

CONCLUSION

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

Pharmacokinetics and tolerability of cabotegravir and rilpivirine long-acting intramuscular injections to the vastus lateralis (lateral thigh) muscles of healthy adult participants

Cabotegravir + rilpivirine administered via intramuscular gluteal injections is the first complete long-acting (LA) regimen approved for maintaining HIV-1 virologic suppression. The vastus lateralis (lateral) thigh muscle could be a potential alternative site of administration in circumstances such as injection site fatigue, intolerability, or contraindication for gluteal administration. Cabotegravir and rilpivirine pharmacokinetics and participant tolerability were evaluated following single intramuscular injections to the lateral thigh. Healthy adult participants received 4 weeks of daily oral cabotegravir (30 mg) and rilpivirine (25 mg), followed by a 10- to 14-day washout and single 3 mL intramuscular injections of cabotegravir LA 600 mg and rilpivirine LA 900 mg to the lateral thigh. Safety, tolerability, and pharmacokinetics were evaluated through 52 weeks post injection. Pharmacokinetic parameters were estimated using non-compartmental analysis. Fifteen participants (female at birth, n = 6) enrolled. Median age was 33 years. Median weight was 93.6 kg. Median body mass index was 31.4 kg/m2. One participant withdrew due to pregnancy after oral dosing before receiving an injection. Plasma concentrations at Weeks 4 and 8 were 15.4- and 5.3-fold above the protein-adjusted 90% inhibitory concentration for cabotegravir and 4.7- and 2.4-fold for rilpivirine, respectively. The most common injection site reactions were pain [28/28 (100%)], induration [15/28 (54%)], and swelling [12/28 (42%)]; 94% were Grade 1 or 2. Cabotegravir and rilpivirine plasma pharmacokinetic profiles observed in this study support further evaluation of thigh administration in target populations of people living with HIV-1. Tolerability of cabotegravir + rilpivirine LA intramuscular lateral thigh injections was similar to gluteal administration.

HIV Pre-Exposure Prophylaxis: New and Upcoming Drugs to Address the HIV Epidemic

Human immunodeficiency virus (HIV) pre-exposure prophylaxis (PrEP) provides a critical intervention toward ending the HIV epidemic and protecting people with reasons to utilize PrEP. PrEP options continue to expand as new administration modalities offer the potential to tailor PrEP use for individual success. We have provided the evidence for new and emerging antiretroviral agents for PrEP (cabotegravir, lenacapavir, dapivirine, and broadly neutralizing antibodies), divided into pharmacology, animal model, and human data, accompanied by a summary and suggested place in therapy. Cabotegravir is a US Food and Drug Administration (FDA)-approved intramuscular injection given every 2 months with a strong body of evidence demonstrating efficacy for HIV PrEP, lenacapavir administered subcutaneously every 6 months is currently under investigation for HIV PrEP, dapivirine vaginal ring is an available PrEP option for women in certain areas of Africa, and broadly neutralizing monoclonal antibodies have been challenged in demonstrating efficacy in phase 1-2 study for HIV PrEP to date. Clinical literature for individual agents is discussed with data from major studies summarized in tables. This review provides a detailed overview of recently available and premier candidate PrEP drugs.

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

BACKGROUND

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

METHODS

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

FINDINGS

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

INTERPRETATION

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

FUNDING

National Institute of Allergy and Infectious Diseases and ViiV Healthcare.

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.

Breakthrough HIV-1 infection in setting of cabotegravir for HIV pre-exposure prophylaxis

OBJECTIVE

We describe the first case of HIV-1 infection in the setting of long-acting injectable cabotegravir (CAB-LA) for HIV pre-exposure prophylaxis to occur in the real world.

DESIGN

Case report.

METHODS

Electronic medical records were reviewed to assess patient history and CAB-LA administration details. Plasma fourth-generation HIV-1/2 Ag/Ab combination immunoassay and HIV-1 RNA quantitative PCR were performed at each injection visit.

RESULTS

We report a 28-year-old sex-diverse person assigned male at birth who acquired HIV-1 infection 91 days after transitioning from tenofovir alafenamideemtricitabine to CAB-LA despite on-time dosing and appropriate laboratory monitoring.

CONCLUSION

This patient's history suggests HIV infection despite on-time and appropriate CAB-LA injections. To our knowledge, this is the first case of CAB-LA pre-exposure prophylaxis failure outside the setting of a clinical trial and highlights diagnostic and management challenges that may occur with such breakthrough infections.

Safety and Efficacy of Long-Acting Injectable Agents for HIV-1: Systematic Review and Meta-Analysis

BACKGROUND

HIV-1 infection continues to affect global health. Although antiretrovirals can reduce the viral load or prevent HIV-1 infection, current drugs require daily oral use with a high adherence level. Long-acting antiretrovirals (LA-ARVs) significantly improve medication adherence and are essential for HIV-1 prophylaxis and therapy.

OBJECTIVE

This study aimed to investigate the safety and efficacy of long-acting cabotegravir (CAB-LA) and long-acting rilpivirine (RPV-LA) in the prevention and treatment of HIV-1 infection.

METHODS

PubMed, Embase, and the Cochrane Library were searched for studies from database inception to November 12, 2022. We included studies that reported efficacy and safety data on LA-ARV intervention in people living with HIV and excluded reviews, animal studies, and articles with missing or duplicate data. Virological suppression was defined as plasma viral load <50 copies/mL 6 months after antiviral therapy initiation. We extracted outcomes for analysis and expressed dichotomous data as risk ratios (RRs) and continuous data as mean differences. Depending on the heterogeneity assessment, a fixed- or random-effects model was used for data synthesis. We performed subgroup analyses of the partial safety and efficacy outcomes of CAB-LA+RPV-LA. The protocol was registered with the Open Science Framework.

RESULTS

We included 12 trials comprising 10,957 individuals, of which 7 were prevention trials and 5 were treatment trials. CAB-LA and RPV-LA demonstrated safety profiles comparable with those of the placebo in terms of adverse event-related withdrawal. Moreover, the efficacy data showed that CAB-LA had a better effect on HIV-1 prevention than tenofovir disoproxil fumarate-emtricitabine (17/5161, 0.33% vs 75/5129, 1.46%; RR 0.21, 95% CI 0.07-0.61; I2=70%). Although CAB-LA+RPV-LA had more drug-related adverse events (556/681, 81.6% vs 37/598, 6.2%; RR 12.50, 95% CI 3.98-39.23; I2=85%), a mild or moderate injection site reaction was the most common reaction, and its frequency decreased over time. The efficacy of CAB-LA+RPV-LA was comparable with that of daily oral drugs at 48 and 96 weeks (1302/1424, 91.43% vs 915/993, 92.2%; RR 0.99, 95% CI 0.97-1.02; I2=0%), and a high level of virological suppression of 80.9% (186/230) was maintained even after 5 years of LA-ARV use. Similar efficacy outcomes were observed in both treatment-naive and treatment-experienced patients (849/911, 93.2% vs 615/654, 94%; RR 0.99, 95% CI 0.96-1.02; I2=0%). According to the questionnaires, more than 85% of people living with HIV favored LA-ARVs.

CONCLUSIONS

LA-ARVs showed favorable safety profiles for both the prevention and treatment of HIV-1 infection and were well tolerated. CAB-LA has more satisfactory efficacy than tenofovir disoproxil fumarate-emtricitabine, significantly reducing the rate of HIV-1 infection. CAB-LA+RPV-LA maintains virological suppression for a long time and may be a viable switching strategy with enhanced public health benefits by reducing transmission. However, further trials are required to confirm the efficacy of these drugs.

A Retrospective Analysis of Preclinical and Clinical Pharmacokinetics from Administration of Long-Acting Aqueous Suspensions

Administration of long-acting injectable suspensions is an increasingly common approach to increasing patient compliance and improving therapeutic efficacy through less frequent dosing. While several long-acting suspensions have recently been marketed, parameters modulating drug absorption from suspension-based formulations are not well understood. Further, methods for predicting clinical pharmacokinetic data from preclinical studies are not well established. Together, these limitations hamper compound selection, formulation design and formulation selection through heavy reliance on iterative optimization in preclinical and clinical studies. This article identifies key parameters influencing absorption from suspension-based formulations through compilation and analysis of preclinical and clinical pharmacokinetic data of seven compounds marketed as suspensions; achievable margins for predicting the clinical dose and input rate from preclinical studies as a function of the preclinical species, the clinical injection location and the intended therapeutic duration were also established.

PrEP uptake and persistence amongst HIV-negative women who exchange sex for money or commodities in Kampala, Uganda: A qualitative inquiry assessing the influence of pregnancy

Pregnant young women who exchange sex for money or commodities are at elevated biological and social risk for HIV acquisition. PrEP serves as an effective means of HIV prevention, including during pregnancy. This study aimed to explore attitudes, experiences and challenges with PrEP to understand what motivates or limits PrEP uptake and adherence specifically during pregnancy among this population of young women. Semi-structured interviews were conducted with 23 participants, recruited from the Prevention on PrEP (POPPi) study in the Good Health for Women Project clinic in Kampala, Uganda. POPPi's inclusion criteria comprised of HIV-uninfected women, aged 15-24, who exchange sex for money or commodities. Interviews focused on experience with PrEP and pregnancy. Data were analyzed utilizing a framework analysis approach. Key themes were comprised of participant barriers to and facilitators of PrEP uptake and adherence. Reasons for PrEP initiation included desire for autonomy and agency, mistrust of partners, and social support. Participants expressed challenges with initiating or sustaining their use of PrEP, including pregnancy, PrEP access and perceived or felt stigma. During pregnancy, participants' primary motivators for altering PrEP use were either understanding of PrEP safety for their baby or changes in perceptions of their HIV risk. Many of these factors were similar across participants who had experience with pregnancy and those who did not. This study highlights the importance of addressing barriers to and facilitators of PrEP uptake and persistence, especially during pregnancy where risk is elevated, with a multi-level approach. Community-oriented education, stigma reduction activities alongside access to PrEP, can serve as means for adherence. The development of robust PrEP support services and guidelines regarding PrEP use during pregnancy among high-risk women, and strategies for their implementation, are of utmost importance for the control of HIV in key populations and the elimination of mother-to-child transmission of HIV.

Pre-exposure prophylaxis uptake for high-risk men who have sex with men in China: a multi-city cross-sectional survey

BACKGROUND

Pre-exposure prophylaxis (PrEP) is a proven biomedical strategy to prevent HIV transmission among men who have sex with men (MSM). Despite oral PrEP is safe and effective in MSM, the use of PrEP has been discouraging, especially in high-risk MSM. And there are no relevant studies showing the use of PrEP in high-risk MSM. The purpose of this study was to get the rate of PrEP use and the factors influencing PrEP use among high-risk MSM.

METHODS

A cross-sectional study was conducted through an electronic questionnaire on the "i guardian Platform", and "snowballing" method was used to recruit MSM in six cities in China, including Beijing, Shenzhen, Chengdu, Changsha, Jinan and Nanjing in China, from January to April 2021. Univariate and multivariate logistic regression analysis were used to analyze the factors associated with the use of PrEP among high-risk MSM who had heard about PrEP.

RESULTS

Among the 1865 high-risk MSM who had heard of PrEP, the rates of those who were willing to use PrEP, had knowledge awareness of PrEP, and had used PrEP were 96.7%, 24.7%, and 22.4%, respectively. Multivariate logistic regression analysis of PrEP use in high-risk MSM showed that more PrEP was used by those who were 26 years or older (OR = 1.86, 95%CI 1.17 ~ 2.99), had master degree or above (OR = 2.37, 95% CI 1.21 ~ 4.72), had unstable work (OR = 1.86, 95% CI 1.16 ~ 2.96), had tested five or more HIV times in the past year (OR = 3.09, 95% CI 1.65 ~ 6.04), had consulted PrEP (OR = 22.05, 95% CI 14.87 ~ 33.91) and had PrEP knowledge awareness (OR = 1.90, 95% CI 1.41 ~ 2.55) (P < 0.05).

CONCLUSIONS

The rate of PrEP use in high-risk MSM was relatively low. PrEP was used more by high-risk MSM with unstable jobs, higher education, frequent HIV testing, and PrEP counseling. Public education on PrEP for MSM should continue to be enhanced to help them use PrEP in a timely and accurate manner.

Dose-Ranging Plasma and Genital Tissue Pharmacokinetics and Biodegradation of Ultra-Long-Acting Cabotegravir In Situ Forming Implant

HIV continues to affect millions of men and women worldwide. The development of long-acting injectables for HIV prevention can overcome adherence challenges with daily oral prevention regimens by reducing dosing frequency and stigma. We previously developed an ultra-long-acting injectable, biodegradable, and removeable in situ forming implant (ISFI) with cabotegravir (CAB) that demonstrated protection after multiple rectal SHIV challenges in female macaques. Here, we sought to further characterize CAB ISFI pharmacokinetics (PK) in mice by assessing the effect of dose and number of injections on CAB PK, time to completion of CAB release and polymer degradation, long-term genital tissue PK, and CAB PK tail after implant removal. CAB concentrations in plasma were above the benchmark for protection for 11-12 months with proportionality between dose and drug exposure. CAB ISFI exhibited high concentrations in vaginal, cervical, and rectal tissues for up to 180 days. Furthermore, depots were easily retrievable up to 180 days post-administration with up to 34% residual CAB and near complete (85%) polymer degradation quantified in depots ex vivo. After depot removal, results demonstrated a median 11-fold decline in CAB plasma concentrations across all doses. Ultimately, this study provided critical PK information for the CAB ISFI formulation that could aid in its future translation to clinical studies.

Safety and efficacy of long-acting injectable cabotegravir as preexposure prophylaxis to prevent HIV acquisition

OBJECTIVE

HIV remains a significant burden, despite expanding HIV prevention tools. Long-acting injectable cabotegravir (CAB-LA) is a new preexposure prophylaxis (PrEP) product. We reviewed existing evidence to determine the efficacy and safety of CAB-LA as PrEP to inform global guidelines.

DESIGN

Systematic review and meta-analysis.

METHODS

We systematically reviewed electronic databases and conference abstracts for citations on CAB-LA from January 2010 to September 2021. Outcomes included HIV infection, adverse events, drug resistance, pregnancy-related adverse events, and sexual behavior. We calculated pooled effect estimates using random-effects meta-analysis and summarized other results narratively.

RESULTS

We identified 12 articles/abstracts representing four multisite randomized controlled trials. Study populations included cisgender men, cisgender women, and transgender women. The pooled relative risk of HIV acquisition comparing CAB-LA to oral PrEP within efficacy studies was 0.21 (95% confidence interval: 0.07-0.61), resulting in a 79% reduction in HIV risk. Rates of adverse events were similar across study groups. Of 19 HIV infections among those randomized to CAB-LA with results available, seven had integrase strand transfer inhibitor (INSTI) resistance. Data on pregnancy-related adverse events were sparse. No studies reported on sexual behavior.

CONCLUSIONS

CAB-LA is highly efficacious for HIV prevention with few safety concerns. CAB-LA may lead to an increased risk of INSTI resistance among those who have acute HIV infection at initiation or become infected while taking CAB-LA. However, results are limited to controlled studies; more research is needed on real-world implementation. Additional data are needed on the safety of CAB-LA during pregnancy (for mothers and infants) and among populations not included in the trials.

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.

Geographic Disparities in Availability of Spanish-Language PrEP Services Among Latino Sexual Minority Men in South Florida

Latino sexual minority men (LSMM) experience barriers in accessing HIV pre-exposure prophylaxis (PrEP), such as lack of proximate culturally-appropriate PrEP navigation services. We examined associations between LSMM's immigration status and Spanish-language PrEP service availability. LSMM clinically indicated for PrEP were recruited from October 2018 to August 2019 in South Florida and completed an interviewer-administered questionnaire. PrEP service navigators in South Florida were identified using the CDC PrEP Directory. We constructed network service areas of 1-, 2-, and 5-miles from Spanish-speaking PrEP navigators. We used multilevel logistic regression to examine associations of individual (i.e., age, income, immigration status, network density) and zip code-level (i.e., population density, poverty, HIV risk) measures with availability of Spanish-language PrEP navigation services. A total of 131 participants clustered into 60 zip codes in South Florida. Latin American-born LSMM reported higher immigration and discrimination stress, and were 91% less likely to have PrEP navigation service availability, relative to LSMM born in the US. Zip code-level HIV incidence was associated with higher service availability within a 1-mile network of Spanish-speaking PrEP navigators. Spanish-language PrEP navigation services were available in high-HIV incidence zip codes; however, Latin American-born LSMM experienced reduced availability. Immigration and discrimination stress may explain lack of availability.

Cabotegravir: The First Long-Acting Injectable for HIV Preexposure Prophylaxis

OBJECTIVE

Review the pharmacology, pharmacokinetics, efficacy, safety, and role of long-acting injectable cabotegravir (CAB-LA) in HIV preexposure prophylaxis (PrEP).

DATA SOURCES

A literature search was performed using PubMed and Google Scholar (2012 to April 2022) with the search terms cabotegravir, preexposure prophylaxis, and PrEP. Other resources included abstracts presented at recent conferences, the manufacturer's Web site, prescribing information, and review articles.

STUDY SELECTION AND DATA EXTRACTION

All English-language articles of studies assessing the efficacy and safety of CAB-LA for PrEP were included.

DATA SYNTHESIS

CAB-LA is the first long-acting injectable therapy approved for HIV-1 PrEP in both men and women. It is a suspension given intramuscularly every other month. CAB-LA has been shown to be more effective than daily oral tenofovir disoproxil fumarate/emtricitabine (TDF/FTC) in preventing HIV-1 infection among high-risk individuals. Two phase 3 trials were stopped early on the basis of superior efficacy of CAB-LA. The most common adverse effects were injection site reactions (ISRs), although they tended to decrease over time, and few participants in clinical trials discontinued use due to ISRs.

RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE

CAB-LA may be particularly useful for individuals with known adherence problems to oral therapy, those with renal impairment, and those with decreased bone mineral density. However, CAB-LA is more expensive than generic TDF/FTC and may be associated with weight gain.

CONCLUSIONS

CAB-LA is the first long-acting injectable agent for HIV PrEP. It is more effective than oral TDF/FTC, is well-tolerated aside from ISRs, and has few clinically significant drug-drug interactions.

Ultra-long-acting in-situ forming implants with cabotegravir protect female macaques against rectal SHIV infection

Ultra-long-acting delivery platforms for HIV pre-exposure prophylaxis (PrEP) may increase adherence and maximize public health benefit. We report on an injectable, biodegradable, and removable in-situ forming implant (ISFI) that is administered subcutaneously and can release the integrase inhibitor cabotegravir (CAB) above protective benchmarks for more than 6 months. CAB ISFIs are well-tolerated in female mice and female macaques showing no signs of toxicity or chronic inflammation. In macaques, median plasma CAB concentrations exceed established PrEP protection benchmarks within 3 weeks and confer complete protection against repeated rectal SHIV challenges. Implant removal via a small incision in 2 macaques at week 12 results in a 7- to 48-fold decrease in plasma CAB levels within 72 hours. Modeling to translate CAB ISFI dosing suggests that a 3 mL injection would exceed protective benchmarks in humans for over 5 months post administration. Our results support the clinical advancement of CAB ISFIs for ultra-long-acting PrEP in humans.

Acceptability and feasibility of long-acting injectable antiretroviral therapy for HIV-infected persons who inject drugs in Vietnam: A qualitative study

BACKGROUND

In Vietnam, HIV prevalence among people who inject drugs (PWID) is several times higher than in the general population (15% versus 0.3%). PWID also experience higher rates of HIV-related mortality, driven by poor antiretroviral therapy (ART) adherence. Long-acting injectable ART (LAI) is a compelling opportunity to improve treatment outcomes, but acceptability and feasibility among HIV-infected PWID remains unexplored.

METHODS

We conducted key informant in-depth interviews in Hanoi, Vietnam (February-November 2021). Participants were purposively sampled and included policymakers, ART clinic staff, and HIV-infected PWID. We applied the Consolidated Framework for Implementation Research to guide study design and analysis, using thematic coding to develop and iteratively refine a codebook and characterize barriers and facilitators to LAI implementation.

FINDINGS

We interviewed 38 key stakeholders: 19 PWID, 14 ART clinic staff, and five policymakers. Participants were enthusiastic about LAI convenience, highlighting less frequent and more discreet dosing. However, contrasting providers, several policymakers suggested LAI was not needed given perceived exceptional oral ART outcomes and rare viral failure among PWID. Policymakers also criticized strategies prioritizing PWID for LAI, emphasizing equity, whereas providers identified PWID as an ideal population for LAI given adherence challenges. LAI complexity, including storage and administration logistics, were deemed surmountable with training and resources. Finally, providers and policymakers acknowledged that adding LAI to drug formularies was key, but an onerous process.

INTERPRETATION

Although anticipated to be resource-intensive, LAI was a welcome addition for interviewed stakeholders and likely an acceptable alternative to oral ART among PWID living with HIV in Vietnam. Despite enthusiasm among PWID and providers that LAI could improve viral outcomes, some policymakers-whose buy-in is critical to LAI implementation-opposed strategies that preferentially distributed LAI to PWID, highlighting values of equity and revealing differences in perceived HIV outcomes among PWID. Results provide a vital foundation for developing LAI implementation strategies.

FUNDING

Supported by National Institutes of Health.

Planning for decentralized, simplified prEP: Learnings from potential end users in Ga-Rankuwa, gauteng, South Africa

Background

In South Africa, youth experience challenges with oral Pre-Exposure Prophylaxis (PrEP) access and uptake. Taking services out of healthcare settings has the potential to increase reach and overcome these challenges. This paper presents young and older people's preferences for decentralized, simplified PrEP service delivery and new long-acting HIV prevention methods, in Ga-Rankuwa, South Africa.

Methods

Between May and August 2021, both PrEP user and non-user adolescent girls and young women (AGYW), pregnant AGYW, female sex workers, adolescent boys and young men (ABYM), and men who have sex with men (MSM) were recruited to participate in focus group discussions (FDGs) in Ga-Rankuwa, Gauteng. Twenty-two FGDs were conducted. Participants were asked about PrEP uptake, potential acceptability of long-acting HIV prevention products, provision of integrated, simplified, and decentralized services, and digital tools to facilitate access to PrEP and other SRH services. A qualitative approach using inductive thematic analysis was carried out to explore emerging themes on decentralized, simplified delivery and the acceptability of long-acting methods.

Results

Of the 109 participants included in the study approximately 45% (n = 50) were female, the median age was 23 years ± 5.3. A third (n = 37) were current or previous PrEP users, of which, 59.5% (n = 22) collected PrEP refills from the clinic. Decentralized, simplified service delivery was appealing; health facilities, pharmacies and institutions of learning were preferred as service points for PrEP and SRH services, and recreational spaces preferred for dissemination of health information and engagement. ABYM were more open to having recreational spaces as service points. Long-acting Cabotegravir was preferred over the Dapivirine Vaginal Ring due to concerns around perceived side-effects, efficacy, and comfort.

Conclusion

Providing long-acting PrEP methods through decentralized, simplified service delivery was appealing to this population. They provided practical locations for decentralized service provision to potentially increase their engagement with and uptake of HIV prevention and SRH services.

The Long-Acting Cabotegravir Tail as an Implementation Challenge: Planning for Safe Discontinuation

The long-acting feature of cabotegravir, an integrase-inhibitor highly effective in preventing acquisition of HIV in adolescents and adults, is both its greatest strength and a challenge to its implementation. Cab-LA is administered at 8-week intervals (after an initial loading dose) but has a long, variable drug "tail" that may leave users vulnerable to future drug resistance if they contract HIV during this critical period. The potential for cab-LA to meaningfully contribute to ending the HIV Epidemic is hindered by, among other factors, limited resources to guide patients and providers on how to safely discontinue injections. We suggest three key strategies to overcome this specific challenge: (1) Comprehensive patient education and counseling about the drug tail; (2) Training and coaching PrEP care teams, including clinical and non-clinical staff, on communication around the tail; (3) Adherence support strategies, including monitoring of cabotegravir drug levels after discontinuation, for a personalized medicine approach to safe discontinuation.

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.

Women for science and science for women: Gaps, challenges and opportunities towards optimizing pre-exposure prophylaxis for HIV-1 prevention

Preventing new HIV infections remains a global challenge. Young women continue to bear a disproportionate burden of infection. Oral pre-exposure prophylaxis (PrEP), offers a novel women-initiated prevention technology and PrEP trials completed to date underscore the importance of their inclusion early in trials evaluating new HIV PrEP technologies. Data from completed topical and systemic PrEP trials highlight the role of gender specific physiological and social factors that impact PrEP uptake, adherence and efficacy. Here we review the past and current developments of HIV-1 prevention options for women with special focus on PrEP considering the diverse factors that can impact PrEP efficacy. Furthermore, we highlight the importance of inclusion of female scientists, clinicians, and community advocates in scientific efforts to further improve HIV prevention strategies.

Long-acting injectable cabotegravir for PrEP: A game-changer in HIV prevention?

BACKGROUND

Long-acting injectable cabotegravir (CAB-LA) represents a new additional option for HIV prevention in people at substantial risk of HIV infection that may fill the gaps in pre-exposure prophylaxis (PrEP) uptake, adherence, and retention in users having difficulty with oral PrEP. Data from clinical trials demonstrated that CAB-LA was safe, highly effective, and well-accepted for HIV prevention. However, the occurrence of breakthrough HIV infections despite timely injections, HIV seroconversion timing and patterns, risk of selection and dissemination of resistance-associated mutations to integrase inhibitors, complexity of follow-up, logistical considerations, and its cost effectiveness compared with oral PrEP constitute significant issues for the integration of CAB-LA into clinical routine.

FINDINGS

These concerns need to be addressed before moving forward with large-scale implementation programmes. Pilot and implementation projects are required in the following areas: HIV testing algorithms, patient education, clinic procedures, protocols for switching and discontinuation, efficacy and safety in populations not included in clinical trials, and demedicalization processes. The development of models to increase the uptake of, adherence to, and persistence with and after CAB-LA injections will also be of paramount importance for success. Lessons learned from these projects will increase experience, staff expertise, and organizational and training capacities to support the roll-out of this new agent as part of HIV prevention programmes.

CONCLUSION

CAB-LA has not yet achieved its full potential in HIV prevention, and strong commitment from all stakeholders is required to push CAB-LA as a game-changer in HIV response.

Pharmacokinetics of Long-Acting Aqueous Nano-/Microsuspensions After Intramuscular Administration in Different Animal Species and Humans-a Review

Formulating aqueous suspensions is an attractive strategy to incorporate poorly water-soluble drugs, where the drug release can be tailored to maintain desired release profiles of several weeks to months after parenteral (i.e., intramuscular or subcutaneous) administration. A sustained drug release can be desirable to combat chronic diseases by overcoming pill fatigue of a daily oral intake, hence, improving patient compliance. Although the marketed aqueous suspensions for intramuscular injection efficiently relieve the daily pill burden in chronic diseases, the exact drug release mechanisms remain to be fully unraveled. The in vivo drug release and subsequent absorption to the systemic circulation are influenced by a plethora of variables, resulting in a complex in vivo behavior of aqueous suspensions after intramuscular administration. A better understanding of the factors influencing the in vivo performance of aqueous suspensions could advance their drug development. An overview of the potential influential variables on the drug release after intramuscular injection of aqueous suspensions is provided with, where possible, available pharmacokinetic parameters in humans or other species derived from literature, patents, and clinical trials. These variables can be categorized into drug substance and formulation properties, administration site properties, and the host response towards drug particles. Based on the findings, the most critical factors are particle size, dose level, stabilizing excipient, drug lipophilicity, gender, body mass index, and host response.

A population pharmacokinetic model based on HPTN 077 of long-acting injectable cabotegravir for HIV PrEP

AIMS

Cabotegravir delivered as a long-acting intramuscular injection has shown superior efficacy to oral tenofovir-emtricitabine as pre-exposure prophylaxis (PrEP) for HIV. Cabotegravir pharmacokinetics (PK), like those of other long-acting depot preparations, exhibit variability between individuals and between injection occasions. The aim of this study is to describe the population pharmacokinetics of long-acting cabotegravir (CAB-LA).

METHODS

Using available PK measurements from 133 participants in the HIV Prevention Trials Network (HPTN) 077 trial, we analysed CAB-LA PK data using nonlinear mixed-effects modelling to develop a population PK model.

RESULTS

A two-compartment model with first order absorption best described the CAB-LA PK. The analysis identified between-occasion variability (BOV, i.e., differences in PK within one individual from one injection to the next) as a significant covariate affecting the absorption rate, with an estimated contribution of BOV to PK variability on the absorption rate (ka ) of 38.5%. Sex and body weight were identified as significant covariates influencing the absorption rate and apparent clearance of CAB-LA after intramuscular injection at various doses and frequencies. Male participants had 67% higher ka than female participants. Serially adding to the model body weight on clearance, sex on ka , and BOV on ka led to a decrease in the objective function value (OFV) of 24.4, 36 and 321.4, respectively.

CONCLUSION

The public availability of this model will facilitate and enable a wide variety of future clinically relevant simulations to inform the optimal use of CAB-LA.

Pharmacogenomics of drug transporters for antiretroviral long-acting pre-exposure prophylaxis for HIV

The use of antiretrovirals (ARVs) as oral, topical, or long-acting pre-exposure prophylaxis (PrEP) has emerged as a promising strategy for HIV prevention. Clinical trials testing Truvada® [tenofovir disoproxil fumarate (TDF)/tenofovir (TFV) and emtricitabine (FTC)] as oral or topical PrEP in African women showed mixed results in preventing HIV infections. Since oral and topical PrEP effectiveness is dependent on adequate drug delivery and availability to sites of HIV infection such as the blood and female genital tract (FGT); host biological factors such as drug transporters have been implicated as key regulators of PrEP. Drug transporter expression levels and function have been identified as critical determinants of PrEP efficacy by regulating PrEP pharmacokinetics across various cells and tissues of the blood, renal tissues, FGT mucosal tissues and other immune cells targeted by HIV. In addition, biological factors such as genetic polymorphisms and genital inflammation also influence drug transporter expression levels and functionality. In this review, drug transporters and biological factors modulating drug transporter disposition are used to explain discrepancies observed in PrEP clinical trials. This review also provides insight at a pharmacological level of how these factors further increase the susceptibility of the FGT to HIV infections, subsequently contributing to ineffective PrEP interventions in African women.

Acceptability of injectable pre-exposure prophylaxis among people who inject drugs in three urban U.S. settings

Background

Outbreaks of new HIV transmission among people who inject drugs (PWID) are a major public health concern. Oral daily PrEP, has been identified as a critical addition to the biomedical toolkit for this population. However, limited research on the acceptability of long-acting injectable PrEP has been conducted with this population.

Methods

We conducted a cross sectional multi-site survey with 1127 participants from May 2019–February 2020 to assess the acceptability of novel PrEP regimens. We computed bivariate and multivariable logistic regressions to evaluate correlates of the outcome variable: acceptability of 3-month injectable-PrEP. SAS v.9.4 was used to conduct statistical analysis.

Results

Limited knowledge of or use of PrEP, past or present, was evident within the sample. Injection drug use in the past six months was significantly associated with LA injectable PrEP acceptability, with the odds of acceptability being 1.885 (CI: 1.376, 2.582) times greater than those who did not inject drugs. After adjusting for confounders, injection drug use was significantly associated with the outcome, such that the odds of acceptability of LA injectable PrEP were 1.705 (CI: 1.198, 2.427) times greater among PWID compared to those who did not inject drugs (p < 0.03). The results demonstrate acceptability (38.2%) in a durable (3-month) injectable PrEP modality among participants who also identified as PWID.

Conclusions

PrEP promotion efforts among PWID to increase access to long-acting injectable PrEP are necessary. Through efforts to increase acceptance and regular use of long-acting injectable PrEP, public health strategies may be able to effectively lessen chances of future HIV outbreaks among PWID.

A Pharmacokinetic Dose-Optimization Study of Cabotegravir and Bictegravir in a Mouse Pregnancy Model

Animal pregnancy models can be useful tools to study HIV antiretroviral safety and toxicity and to perform mechanistic studies that are not easily performed in humans. Utilization of clinically relevant dosing in these models improves the relevance of the findings. Cabotegravir and bictegravir are new integrase strand transfer inhibitors (INSTIs), recently approved for the treatment of people living with HIV. Studies of these drugs in pregnancy are very limited. The objective of this study was to perform a dose-optimization study of cabotegravir and bictegravir in a mouse pregnancy model with the goal of determining the dose that would yield plasma drug concentrations similar those observed in humans. Pregnant mice were administered increasing doses of cabotegravir or bictegravir in combination with emtricitabine and tenofovir by oral gavage from gestational day 11.5 to 15.5. Drug concentrations in the maternal plasma at 1 h and 24 h post drug administration and in the amniotic fluid at 1 h post drug administration were determined using high-performance liquid chromatography coupled with tandem mass spectrometry. A review of cabotegravir and bictegravir human pharmacokinetic studies are also reported. We hope these data will encourage studies of HIV antiretroviral safety/toxicity and mechanistic studies in animal pregnancy models.

Short Communication: Population Representation in HIV Cure Research: A Review of Diversity Within HIV Cure Studies Based in the United States

HIV is experienced across diverse populations, with gender and racial/ethnic minority populations bearing a significant proportion of disease. With National Institutes of Health (NIH) placing a priority on the enrollment of women and racial/ethnic minorities into studies, it is important to understand the diversity of participants in research. We sought to characterize how HIV cure research studies report data on diversity. A sampling frame of publications with funding provided by the Martin Delaney Collaboratories for HIV Research in 2019 was reviewed for reporting of demographic data. Of 55 publications that included research on humans/human specimens, only 51% provided any demographic description. There often is insufficient consideration of diversity of populations in HIV cure research. Ameliorating gaps in this regard will require recruitment of diverse populations/specimens and specifications to report demographic data in articles. This will ensure inclusion of diverse participants in HIV cure research from earliest laboratory to eventual phase III studies.

Real-Life Therapeutic Concentration Monitoring of Long-Acting Cabotegravir and Rilpivirine: Preliminary Results of an Ongoing Prospective Observational Study in Switzerland

SHCS#879 is an ongoing Switzerland-wide multicenter observational study conducted within the Swiss HIV Cohort Study (SHCS) for the prospective follow-up of people living with HIV (PLWH) receiving long-acting injectable cabotegravir-rilpivirine (LAI-CAB/RPV). All adults under LAI-CAB/RPV and part of SHCS are enrolled in the project. The study addresses an integrated strategy of treatment monitoring outside the stringent frame of controlled clinical trials, based on relevant patient characteristics, clinical factors, potential drug-drug interactions, and measurement of circulating blood concentrations. So far, 91 blood samples from 46 PLWH have been collected. Most individuals are less than 50 years old, with relatively few comorbidities and comedications. The observed concentrations are globally in accordance with the available values reported in the randomized clinical trials. Yet, low RPV concentrations not exceeding twice the reported protein-adjusted 90% inhibitory concentration have been observed. Data available at present confirm a considerable between-patient variability overall. Based on the growing amount of PK data accumulated during this ongoing study, population pharmacokinetic analysis will characterize individual concentration-time profiles of LAI-CAB/RPV along with their variability in a real-life setting and their association with treatment response and tolerability, thus bringing key data for therapeutic monitoring and precision dosage adjustment of this novel long-acting therapy.

Promises and challenges: cabotegravir for preexposure prophylaxis

PURPOSE OF REVIEW

Tenofovir-based oral PrEP has been effective in reducing population-level HIV incidence in multiple settings, although disparities remain. Injectable cabotegravir-based PrEP is an alternative that may be attractive to individuals with adherence challenges or who do not desire to take a daily medication. We review promises and challenges of cabotegravir-based PrEP.

RECENT FINDINGS

Cabotegravir has demonstrated higher effectiveness than oral PrEP in two randomized trials, with a hazard ratio of 0.31 for HIV incidence among MSM and transgender women across multiple settings [95% confidence interval (CI) 0.18-0.62] and 0.11 for cisgender women in sub-Saharan Africa (95% CI 0.040.32). Cabotegravir was also highly effective among populations with disproportionate HIV incidence. Although cabotegravir breakthrough was rare, diagnosis was delayed with use of antigen/antibody-based HIV tests, and resistance occurred with breakthrough infections. Implementation will need to overcome several challenges, including HIV RNA laboratory monitoring not being widely available, requirement for additional staff time and clinic space, and need to provide oral medication during interruptions in dosing.

SUMMARY

Cabotegravir-based PrEP is a highly effective additional PrEP option that will expand HIV prevention options. For successful roll-out, strategies for streamlined and accessible delivery of cabotegravir in real-world settings will need to be developed.

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.