Long-acting Cabotegravir Research Articles

CD4+/CD8+ improvement after switch from a second-generation integrase inhibitor regimen to long-acting cabotegravir and rilpivirine.

Our study assessed the CD4+/CD8+ ratio in people with HIV (PWH) switching from a second-generation integrase inhibitor regimen to long-acting cabotegravir (CAB) and rilpivirine (RPV). Over one year, we observed a significant improvement in the CD4+/CD8+ ratio; In addition, our data showed that time spent in CAB+RPV was significantly associated with an increased CD4+/CD8+ ratio. These findings suggest that long-acting therapy may enhance immune recovery, also in treatment-experienced PWH.

HIV DNA Levels in Persons Who Acquired HIV in the Setting of Long-Acting Cabotegravir for HIV Prevention: Analysis of Cases from HPTN 083 and 084.

We evaluated HIV DNA levels in individuals who received long-acting cabotegravir (CAB-LA) or tenofovir disoproxil fumarate/emtricitabine (TDF/FTC) pre-exposure prophylaxis in the HPTN 083 and 084 trials and had HIV DNA testing performed to help determine HIV status. HIV DNA testing was performed using peripheral blood mononuclear cell (PBMC) samples collected after a reactive HIV test was obtained at a study site. DNA was quantified using droplet digital PCR (lower limit of detection [LLOD]: 4.09 copies/million PBMCs). Final HIV status and the timing of the first HIV-positive visit were determined by an independent adjudication committee based on HIV test results from real-time site testing and retrospective testing at a centralized laboratory. HIV DNA testing was performed for 133 participants [21 HIV-positive (7 CAB-LA arm, 14 TDF/FTC arm) and 112 HIV-negative; 1-6 tests/person]. For persons with HIV, the time between the first HIV-positive visit and collection of the first sample for DNA testing was a median of 81 days for those receiving CAB-LA (range 41-246) and 11 days for those receiving TDF/FTC (range 3-127). Four (57.1%) of the seven CAB-LA cases with infection had a low initial DNA result [three detected <LLOD; one near the LLOD (4.2 copies/106 PBMCs); in 2/4 cases, the DNA level was still <10 copies/106 PBMCs ≥40 weeks after the first HIV-positive visit. In contrast, only 3/14 (21.4%) of the TDF/FTC cases had a low or negative initial DNA test result (one not detected; two <10 copies/106 PBMCs). In this study, the time between the first HIV-positive visit and the first DNA test was longer in the CAB-LA cases than the TDF/FTC cases. Despite this difference, low or undetectable DNA levels were more frequently observed in the CAB-LA cases. This suggests that CAB-LA exposure may limit seeding of the HIV reservoir in early infection.

Frequency of Major Transmitted Integrase Resistance in Poland Remains Low Despite Change in Subtype Variability

With the widespread use of integrase inhibitors and the expanding use of long-acting cabotegravir in both pre-exposure prophylaxis and antiretroviral treatment, molecular surveillance on the transmission of integrase resistance has regained clinical significance. This study aimed to determine the frequency of INSTI-transmitted drug resistance mutations (DRMs) among treatment-naïve individuals in Poland from 2016 to 2023. INSTI resistance was analyzed in 882 antiretroviral treatment-naïve individuals using Sanger sequencing. Integrase DRMs were defined based on the Stanford HIV drug resistance database scores. Phylogeny was used to investigate subtyping and clustering. For the analysis of time-trends, logistic regression was used. Major (E138K and R263K) integrase mutations were detected in 0.45% of cases with minor resistance observed in 14.85%, most commonly (13.95%) E157Q. Overall, no major clusters of transmitted drug resistance were identified, and the transmission of E157Q showed a decreasing trend (p &lt; 0.001). While the frequency of sub-subtype A6 increased, it was predominantly found among migrants and associated with L74 mutations. The frequency of major integrase-transmitted DRMs remains low, despite the changes in subtype variability. Surveillance of changing HIV molecular variation patterns is vital from the perspective of the optimal use of integrase inhibitors, especially due to expanding long-acting cabotegravir implementation.

Preferential Initiation of Long-Acting Injectable Versus Oral HIV Pre-Exposure Prophylaxis Among Women Who Inject Drugs.

Fifty-five of 62 women who inject drugs (WWID) selected long-acting cabotegravir (CAB-LA) over oral PrEP, and 51/55 received a first injection. More recent injection drug use and number of sexual partners were associated with selecting CAB-LA (P < .05). Findings provide preliminary evidence of a strong preference for longer-acting products among WWID.

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

This study is registered with ClinicalTrials.gov as NCT03164564.

Current opinion: antiretrovirals during pregnancy and breastfeeding

Purpose of review To review the most important literature from the past 2 years on the pharmacokinetics of antiretrovirals in pregnancy, placental transfer, and breastmilk. Recent findings Concentrations of antiretrovirals frequently used in pregnancy and their placental transfer are described, together with infant exposure through breastmilk. Also, applications of ex-vivo and in-silico studies, such as placenta perfusion studies and PBPK models, are discussed. Summary Great efforts were made in the past 2 years to accelerate the availability of data on antiretrovirals during pregnancy and lactation. Bictegravir showed decreased but still sufficient concentrations during pregnancy, leading to a label change by the FDA. In-silico and clinical studies on long-acting cabotegravir and rilpivirine generated information leading to cautious use of these formulations in pregnancy. Low infant exposure to antiretrovirals through breastmilk is expected for most compounds. Despite the impact of these studies, more incentives are needed for earlier implementation, for instance, during the developmental phase of drugs, to provide women antenatally with proper information on their drugs.

Virological History Predicts Non-sustained Viral Suppression With Long-Acting Cabotegravir and Rilpivirine Therapy, Independent of Pharmacokinetic Parameters

Abstract Background This study aimed to investigate factors contributing to non-sustained viral suppression, including intermittent viremia and persistent low-level viremia, during cabotegravir (CAB) plus rilpivirine (RPV) long-acting (LA) injectable therapy, with a focus on pharmacokinetics (PK). Methods A prospective cohort study was conducted on people with human immunodeficiency virus (HIV, PWH) transitioning from stable oral antiretroviral therapy (ART) to bimonthly CAB + RPV LA. Standardized follow-up included close monitoring through blood sampling for plasma human immunodeficiency virus type 1 (HIV-1) viral load (VL) and multiple plasma drug concentrations measurements to analyze the connection between PK parameters and virologic outcomes. Results Among 173 patients with a median (interquartile range [IQR]) follow-up of 11.1(7.1–13.2) months and 789 pre-dose measurements, 38.7% experienced VL ≥ 20 copies/mL, and 16.2% had levels ≥50 copies/mL. Intermittent viremia occurred in 34.7% of patients, and persistent low-level viremia in 4%. Virological failure developed in 2 cases. Predictors of non-sustained viral suppression included VL at HIV diagnosis (adjusted hazard ratio [AHR]: 1.49 per log10 VL, 95% confidence interval [CI]: 1.04–2.12, P = .027), detectable viremia on oral ART (AHR: 2.45, 95% CI: 1.29–4.65, P = .006), and the level of viral suppression at transition (AHR: 0.38, 95% CI: .19–.75, P = .004). We found a significant association between low trough concentrations of CAB and RPV and episodes of detectable viremia exceeding 50 copies/mL. However, none of the assessed PK covariates predicted non-sustained viral suppression in multivariable models. Conclusions Non-sustained viral suppression in PWH transitioning from stable oral ART to CAB + RPV LA was linked to preexisting factors before transition. Higher VL pre-ART and incomplete suppression on oral therapy increased the risk, independent of PK parameters.

Pittsburgh Sleep Quality Index (PSQI) Changes in Virologically Suppressed People Living with HIVSwitching to Long-Acting Cabotegravir and Rilpivirine.

Limited evidence is available about sleep quality changes associated with the use of Cabotegravir (CAB), a new, long-acting (LA) antiretroviral (ARV) drug belonging to the class of Integrase Strand Transfer Inhibitors (INSTIs). Pittsburgh Sleep Quality Index (PSQI) was calculated in 53 people living with HIV (PLWH) under the care of the outpatient services of two Italian Infectious Diseases Centers in Apuliabefore (M0) and seven months after (M7) the switch to LA CAB. Global scores and relative subitems were compared using paired sample tests. The same analysis was repeated in subgroups of PLWH switching from INSTIs-, Dolutegravir-(DTG), and Bictegravir (BIC)-based regimens. A significant reduction was reported in global mean (±StandardDeviation, SD) PSQI at M7 compared to M0 (4 (±3) vs. 3 (±2), p = 0.01), particularly in the areas of sleep latency and sleep disturbances. The improvement was also significant in PLWH already on INSTIs- (from median 3 to 2 points, p = 0.02) and DTG-based (from median 4 to 2, p = 0.01) ARV regimens, but not among those who switched from BIC-based regimens. PLWH reported improved sleep quality after switching from ARV treatment to LA CAB. Further studies are needed to give deeper insights into this phenomenon.

Perceptions of the attributes of new long-acting HIV pre-exposure prophylaxis formulations compared with a daily, oral dose among South African young women: a qualitative study

ABSTRACT Oral PrEP is highly effective against the acquisition of HIV but is underutilised by young women. New options, like the monthly dapivirine vaginal ring (DVR) and injectable long-acting cabotegravir (CAB-LA), are emerging. However, little is known about young women’s perceptions of these alternatives. This qualitative study explored perceptions of the attributes of PrEP technologies in South Africa. Young women accessing sexual health services were purposively selected to participate in 22 in-depth interviews, five focus group discussions and two workshops using the nominal group technique, between August 2022 and March 2023. A thematic approach guided by the diffusion of innovation attributes, including relative advantage, compatibility with the student's lives, complexity of the technology, and trialability, was used for data analysis. The DVR was the least preferred because of lower efficacy, the perceived complexity of inserting it in the vagina and some safety concerns. Oral PrEP, which some had tried and discontinued, was least compatible with students’ busy schedules. Integrating PrEP and contraceptives with similar return visit patterns could enhance service delivery. Intensive demand creation campaigns will be needed to increase PrEP utilisation and dispel myths about the vaginal ring.

First Case of HIV Seroconversion With Integrase Resistance Mutations on Long-Acting Cabotegravir for Prevention in Routine Care.

Long-acting cabotegravir (CAB-LA) is highly effective for HIV prevention, but delayed HIV diagnoses and integrase strand transfer inhibitor (INSTI) resistance were observed in trials. We report the first case in routine clinical care of HIV infection on CAB-LA with INSTI resistance. The SeroPrEP study enrolls individuals in the United States who acquire HIV on pre-exposure prophylaxis modalities to assess diagnostics, antiretroviral (ARV) drug levels, resistance, and treatment outcomes. Resistance mutations in full-length HIV-1 integrase were identified by single-genome sequencing (SGS). Cabotegravir concentrations in plasma and hair segments were measured by liquid chromatography-tandem mass spectrometry. A 23-year-old gender-nonbinary person, male at birth, restarted CAB-LA 6 months after discontinuation due to losing insurance. Prior to restart, HIV-1 RNA was not detected, but 20 days elapsed before CAB-LA injection. After the second CAB-LA injection, HIV antigen/antibody returned reactive (HIV-1 RNA 451 copies/mL). SGS of plasma HIV-1 RNA identified INSTI mutation Q148R in 2/24 sequences 2 days postdiagnosis; commercial genotype failed amplification. Cabotegravir hair concentration was 0.190 ng/mg 2 weeks prediagnosis; plasma cabotegravir was high (3.37 μg/mL; ∼20× PA-IC90) 14 days postdiagnosis. Viral suppression was maintained for 6 months on darunavir/cobicistat/emtricitabine/tenofovir alafenamide, then switched to doravirine + emtricitabine/tenofovir alafenamide due to nausea. In this first case of HIV infection on CAB-LA with INSTI resistance in routine care, cabotegravir resistance was detected only with a sensitive research assay. Accelerated pathways to minimize time between HIV testing and CAB-LA initiation are needed to optimize acute HIV detection and mitigate resistance risk. Sustained product access regardless of insurance is imperative to reduce HIV infections on CAB-LA.

Acceptability of Long-Acting Cabotegravir + Rilpivirine in a Large, Urban, Ambulatory HIV Clinic.

Outside of randomized controlled trials (RCTs), there are limited data regarding the acceptability of injectable long-acting cabotegravir + rilpivirine (LA-CAB+RPV) among persons living with HIV (PLWH). To evaluate acceptability, we describe participant-reported outcomes (PRO) of LA-CAB+RPV among a population underrepresented in RCTs. Ruth M. Rothstein Core Center (CORE), large urban HIV clinic in Chicago, Illinois, USA. We interviewed PLWH prescribed LA-CAB+RPV who receive primary care at CORE. PRO endpoints included treatment satisfaction, tolerability of injections, reasons for switching to LA-CAB+RPV, and unexpected effects of LA-CAB+RPV. Mean and standard deviations (mean±SD) and proportions (%) are reported. Among respondents (N=150), 67% identified as Non-Hispanic Black, 24% Hispanic, 56% male; the average age was 43 years (SD:13.2), and 37% were ≥50 years old. Most respondents (93%) completed ≥3 injection appointments at the time of interview. The most common reasons for switching to LA-CAB+RPV were no longer wanting to take pills (89%) and trouble taking their pills daily (58%). Treatment satisfaction was high (6.7±0.5 out of 7). Two-thirds (61%) reported an unexpected aspect of their life improved. Pain from injections was common (98%), with a mean pain score of 4.3 out of 10. Among those reporting pain, half (47%) reported pain decreased after initial injection. Among participants reporting pain score >6 (n=36), most (78%) reported no improvement since initial injection. We found high treatment satisfaction with LA-CAB+RPV in a diverse population. Participants reported moderate injection pain, which improved with time. Results suggest injectable LA-CAB+RPV will be met with acceptability across diverse participant populations.

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

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.

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).

Implementation of long-acting cabotegravir and rilpivirine: primary results from the perspective of staff study participants in the Cabotegravir And Rilpivirine Implementation Study in European Locations.

Cabotegravir plus rilpivirine (CAB + RPV) is the first complete long-acting (LA) regimen recommended for maintaining HIV-1 virological suppression. Cabotegravir And Rilpivirine Implementation Study in European Locations (CARISEL) is an implementation-effectiveness study examining the implementation of CAB+RPV LA administered every 2 months (Q2M) in European HIV centres. We present staff study participant (SSP) perspectives on the administration of CAB+RPV LA over 12 months. Eighteen clinics were randomized to one of two implementation support packages: standard arm (Arm-S) or enhanced arm (Arm-E). Arm-S included video injection training and provider/patient toolkits. Additionally, Arm-E included skilled wrap-around team meetings, face-to-face injection training and continuous quality improvement (CQI) calls. SSPs completed surveys on the acceptability, appropriateness and feasibility of CAB+RPV LA as an intervention and its implementation into their clinics, as well as barriers and facilitators to implementation. All surveys were completed at Month (M)1 (baseline), M5 and M12; data collection was completed by February 2022. Qualitative data were obtained from semi-structured interviews at M1, M5 and M12. The primary objective was assessed via formal statistical comparisons between study arms of the Acceptability of Implementation Measure, Implementation Appropriateness Measure and Feasibility of Implementation Measure surveys (1-5 Likert scale ranging from 1 = "completely disagree" to 5 = "completely agree"). Equivalent measures anchored to CAB+RPV LA as a therapy were also assessed. Seventy SSPs completed surveys and interviews at M1, 68 at M5 and 62 at M12. Mean acceptability/appropriateness/feasibility scores were ≥3.8 (out of 5) at M12 for implementation- and intervention-based measures. An analysis of covariance showed no significant differences between study arms for these outcomes. Although barriers were noted, most SSPs were not overly concerned that these would impact implementation; concern about these anticipated barriers also decreased over time. At M12, 90.3% (n = 56/62) of SSPs held a positive opinion about CAB+RPV LA implementation. Qualitative interviews and CQI calls highlighted three top practices that supported implementation: implementation planning; education about CAB+RPV LA clinical efficacy; and education around administering injections and managing pain/discomfort after injections. CARISEL demonstrated that CAB+RPV LA dosed Q2M was successfully implemented across a range of European locations, with SSPs finding implementation highly acceptable, appropriate and feasible. NCT04399551.

Clinical pharmacology considerations and drug-drug interactions with long-acting cabotegravir and rilpivirine relevant to sub-Saharan Africa.

Long-acting injectable (LAI) cabotegravir and rilpivirine for HIV treatment and LAI cabotegravir for pre-exposure HIV prophylaxis are being rolled out in a multitude of countries worldwide. Due to the prolonged exposure, it can be challenging to undertake 'traditional' pharmacokinetic studies and current guidance is derived from their oral equivalents or physiologically based pharmacokinetic studies. This review aims to consider pharmacokinetic characteristics of cabotegravir and rilpivirine and describe anticipated drug-drug interactions (DDIs) with frequent concomitant medications in African settings. Relevant co-medications were identified from the WHO 2021 List of Essential Medicines. All original human and physiologically based pharmacokinetic studies published in English on PubMed, discussing DDIs with LAI cabotegravir and rilpivirine prior to April 2023, were reviewed. The Liverpool HIV interaction database was also reviewed (https://www.hiv-druginteractions.org/checker). LAI cabotegravir and rilpivirine have half-lives of 6-12 and 13-28 weeks, respectively. Cabotegravir is primarily metabolized by UDP-glucuronyltransferase (UGT)-1A1 and rilpivirine by cytochrome P450 (CYP)-3A4. LAI cabotegravir and rilpivirine themselves exhibit low risk of perpetrating interactions with co-medications as they do not induce or inhibit the major drug metabolizing enzymes. However, they are victims of DDIs relating to the induction of their metabolizing enzymes by concomitantly administered medication. Noteworthy contraindicated co-medications include rifamycins, carbamazepine, phenytoin, flucloxacillin and griseofulvin, which induce CYP3A4 and/or UGT1A1, causing clinically significant reduced concentrations of rilpivirine and/or cabotegravir. In addition to virologic failure, subtherapeutic concentrations resulting from DDIs can lead to emergent drug resistance. Clinicians should be aware of potential DDIs and counsel people receiving LAI cabotegravir/rilpivirine appropriately to minimize risk.

One Year of Long-Acting Cabotegravir and Rilpivirine in People With Human Immunodeficiency Virus and Long Exposure to Antiretroviral Therapy: Data From the SCohoLART Study.

The aim of the study was to evaluate the 12-month cumulative probability of treatment discontinuation (TD) in people with human immunodeficiency virus (HIV; PWH) and a long exposure to antiretroviral therapy (ART) switching to long-acting cabotegravir and rilpivirine (CAB/RPV). SCohoLART is a single-center, prospective, cohort study designed to collect both samples and clinical data from PWH with virological suppression who switched to bimonthly long-acting CAB/RPV. TD occurred at switch to another regimen for any reason including virological failure (VF); VF was defined as HIV RNA levels ≥50 copies/mL at 2 consecutive measurements or a single HIV RNA level ≥1000 copies/mL. Results were reported as median (interquartile range [IQR]) or frequency (percentage). Cumulative probabilities of TD were estimated using Kaplan-Meier curves. We evaluated 514 participants; 467 (90.9%) were male, and their median age (IQR) was 49 (40-56) years. At the time of switching, the median time from HIV diagnosis and the median duration of ART were 14.0 (IQR, 8.8-20.5) and 11.4 (7.9-17.4) years, respectively; before starting CAB/RPV, the median number of antiretroviral regimens was 3 (2-4). During a median study follow-up (IQR) of 13.1 (9.1-15.5) months, 52 PWH (10.1%) experienced TD, including 4 (0.8%) for VF. The 12-month cumulative probability of TD was 11% (95% confidence interval, 8%-14%). The main cause of TD was injection site reaction (15 participants [28.8%]). The 1-year cumulative probability of TD with long-acting CAB/RPV was quite low in this cohort of people with a median exposure to ART of 10 years, in whom injection site reaction was the leading cause of TD. VFs were rare during study follow-up.

EE281 Cost-Effectiveness of Every Two Month Cabotegravir Long-Acting (CAB-LA) for Pre-Exposure Prophylaxis (PREP) Compared with Daily Oral Tenofovir Disoproxil Fumarate (TDF)/ Emtricitabine (FTC) As Prep to Prevent HIV-1 in the UK

EE281 Cost-Effectiveness of Every Two Month Cabotegravir Long-Acting (CAB-LA) for Pre-Exposure Prophylaxis (PREP) Compared with Daily Oral Tenofovir Disoproxil Fumarate (TDF)/ Emtricitabine (FTC) As Prep to Prevent HIV-1 in the UK

Switch to long-acting cabotegravir and rilpivirine in virologically suppressed adults with HIV in Africa (CARES): week 48 results from a randomised, multicentre, open-label, non-inferiority trial

Long-acting injectable cabotegravir and rilpivirine is licensed for individualised treatment of HIV-1 infection in resource-rich settings. Additional evidence is required to support use in African treatment programmes where demographic factors, viral subtypes, previous treatment, and delivery and monitoring approaches differ. The aim of this study was to determine whether switching to long-acting therapy with injections every 8 weeks is non-inferior to daily oral therapy in Africa. CARES is a randomised, open-label, non-inferiority trial being conducted at eight sites in Uganda, Kenya, and South Africa. Participants with HIV viral load below 50 copies per mL on oral antiretroviral therapy and no history of virological failure were randomly assigned (1:1; web-based, permuted blocks) to receive cabotegravir (600 mg) and rilpivirine (900 mg) by intramuscular injection every 8 weeks, or to continue oral therapy. Viral load was monitored every 24 weeks. The primary outcome was week 48 viral load below 50 copies per mL, assessed with the Food and Drug Administration snapshot algorithm (non-inferiority margin 10 percentage points) in the intention-to-treat exposed population. This trial is registered with the Pan African Clinical Trials Registry (202104874490818) and is ongoing up to 96 weeks. Between Sept 1, 2021, and Aug 31, 2022, we enrolled 512 participants (295 [58%] female; 380 [74%] previous non-nucleoside reverse transcriptase inhibitor exposure). Week 48 viral load was below 50 copies per mL in 246 (96%) of 255 participants in the long-acting therapy group and 250 (97%) of 257 in the oral therapy group (difference -0·8 percentage points; 95% CI -3·7 to 2·3), demonstrating non-inferiority (confirmed in per-protocol analysis). Two participants had virological failure in the long-acting therapy group, both with drug resistance; none had virological failure in the oral therapy group. Adverse events of grade 3 or greater severity occurred in 24 (9%) participants on long-acting therapy and ten (4%) on oral therapy; one participant discontinued long-acting therapy (for injection-site reaction). Long-acting therapy had non-inferior efficacy compared with oral therapy, with a good safety profile, and can be considered for African treatment programmes. Janssen.

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.

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

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. 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. 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). 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.