Expanded Multivariable Models to Assist Patient Selection for Long-Acting Cabotegravir + Rilpivirine Treatment: Clinical Utility of a Combination of Patient, Drug Concentration, and Viral Factors Associated With Virologic Failure

Population Pharmacokinetics of Cabotegravir Following Oral Administration and Long-Acting Intramuscular Injection in Real-World People with HIV

Long-acting cabotegravir has been studied mainly in the stringent framework of clinical trials, which does not necessarily reflect the situation of people with HIV (PWH) in routine clinical settings. The present population pharmacokinetic analysis aims to build real-world reference percentile curves of cabotegravir concentrations, accounting for patient-related factors that may affect cabotegravir exposure. The second objective is to simulate whether dosing interval adjustments of cabotegravir could be considered in specific subpopulations. Overall, 238 PWH contributed to 1,038 cabotegravir levels (186 during the initial oral administration phase and 852 after intramuscular injection). Cabotegravir pharmacokinetics was best described using a one-compartment model with distinct first order-absorption for oral and intramuscular administrations, and identical volume and clearance. Our model showed almost 40% faster absorption and 30% higher clearance than previously reported, resulting in a time to steady-state of 8 months and an elimination half-life of 4.6 weeks for long-acting cabotegravir. Sex and body mass index significantly influenced absorption, and bodyweight affected clearance. Model-based simulations showed that cabotegravir trough concentrations in females were 25% lower 4 weeks after the intramuscular loading dose, but 42% higher during the late maintenance phase. Finally, simulations indicated that in females, despite significantly higher cabotegravir concentrations, longer intervals between injections may not consistently ensure levels above the 4-fold protein-adjusted 90% inhibitory target concentration.

Rilpivirine and cabotegravir trough concentrations in people with HIV on long-term treatment with long-acting injectable antiretrovirals

OBJECTIVE

Large inter-individual variability in the pharmacokinetics of rilpivirine and cabotegravir has been reported in the first weeks after starting long-acting injectable (LAI) therapy. Here, we assessed the distribution of rilpivirine and cabotegravir trough concentrations in people with HIV (PWH) on long-term LAI treatment.

METHODS

Adult PWH treated with LAI for at least 32 weeks with an assessment of drug plasma trough concentrations were considered. The proportion of rilpivirine and cabotegravir plasma trough concentrations below four-times the protein-adjusted concentrations required for 90% inhibition of viral replication (4×PA-IC90) was estimated.

RESULTS

Sixty-seven PWH were identified. LAI treatment duration was 216 ± 80 weeks (range 32-320 weeks). Cabotegravir concentrations were associated with lower inter-individual variability compared with rilpivirine (45% versus 84%; P < 0.05). No differences were found in rilpivirine (160 ± 118 versus 189 ± 81 ng/mL; P = 0.430) and cabotegravir (1758 ± 807 versus 1969 ± 802 ng/mL; P = 0.416) trough concentrations in males (n = 55) versus females (n = 12). A non-significant trend for lower cabotegravir concentrations was found in PWH with a body mass index >30 kg/m2 (n = 9) versus non-obese participants (1916 ± 905 versus 1606 ± 576 ng/mL; P = 0.131). Three out of the 67 PWH had at least one drug concentration <4×PA-IC90: 100% of PWH had undetectable HIV viral load.

CONCLUSIONS

At steady state, optimal systemic exposure of cabotegravir and rilpivirine was found in most PWH; cabotegravir trough concentrations were associated with lower inter-individual variability compared with rilpivirine. The study was not powered to assess the contribution of sex and/or body weight on LAI exposure due to the small number of females and obese PWH included.

Comparison of HIV-1 DNA load measurements in blood and in relation to successful proviral sequencing

OBJECTIVE

HIV DNA sequencing is now routinely used for HIV-infected individuals on antiretroviral therapy (ART) with or without partial genotypic history. Successful amplification of HIV pol gene has yet to be correlated with HIV DNA levels. Here, we assessed the relationship between HIV DNA load and sequencing results.

METHODS

We analyzed three different qPCR measurements of total (LTR and LTR-gag) and integrated (Alu-LTR) HIV DNA in blood samples collected from viremic as well as virally suppressed HIV-infected individuals on ART. HIV DNA levels were compared to HIV DNA Sanger sequencing and clinical and therapeutic parameters.

RESULTS

Among the 135 individuals analyzed for HIV DNA measurements and sequencing, all three HIV DNA measurements were associated with HIV DNA Sanger sequencing results. A threshold of around 2 and 1.5 log copies/million leukocytes of total HIV DNA was identified for LTR and LTR-gag qPCRs, respectively. Integrated HIV DNA positivity was also associated with successful sequencing. We further compared HIV DNA measurement techniques in an extended cohort of 312 individuals and showed that all measurements correlated between the different techniques, regardless of the HIV-1 subtypes analyzed. However, higher detection rates were observed with LTR (96%) compared to LTR-gag (86%) and Alu-LTR (59%) qPCRs. Duration of virological control on ART and CD4 nadir were the main determinants of HIV reservoir size.

CONCLUSIONS

HIV DNA measurement is associated with Sanger sequencing success, regardless of the technique used. In a clinical setting, Application of HIV DNA quantification before sequencing should be further evaluated.

Phylodynamic evolution of HIV-1 A6 sub-subtype epidemics in Poland

The human immunodeficiency virus type 1 (HIV-1) A6 sub-subtype is highly prevalent in Eastern Europe. Over the past decade, the dissemination of the A6 lineage has been expanding in Poland. The recent Russian invasion of Ukraine may further escalate the spread of this sub-subtype. While evolutionary studies using viral sequences have been instrumental in identifying the HIV epidemic patterns, the origins, and dynamics of the A6 sub-subtype in Poland remain to be explored. We analyzed 1185 HIV-1 A6 pol sequences from Poland, along with 8318 publicly available sequences from other countries. For analyses, phylogenetic tree construction, population dynamics inference, Bayesian analysis, and discrete phylogeographic modeling were employed. Of the introduction events to Poland, 69.94% originated from Ukraine, followed by 29.17% from Russia. Most A6 sequences in Poland (53.16%) formed four large clades, with their introductions spanning 1993-2008. Central and Southern Polish regions significantly influenced migration events. Transmissions among men who have sex with men (MSM) emerged as the dominant risk group for virus circulation, representing 72.92% of migration events. Sequences from migrants were found primarily outside the large clades. Past migration from Ukraine has fueled the spread of the A6 sub-subtype and the current influx of war-displaced people maintains the growing national epidemic.

Guidance for the Interpretation of Long-Acting Cabotegravir and Rilpivirine Concentrations Based on Real-World Therapeutic Drug Monitoring Data and Documented Failures

The interpretation of long-acting cabotegravir and rilpivirine concentrations is complicated by the lack of consensus on the threshold to consider. Building on real-world therapeutic drug monitoring data and documented virologic failures, this article provides a reappraisal of the existing thresholds and guidance for the interpretation of cabotegravir and rilpivirine concentrations.

Real-world trough concentrations and effectiveness of long-acting cabotegravir and rilpivirine: a multicenter prospective observational study in Switzerland

Background

The efficacy and tolerability of long-acting cabotegravir and rilpivirine were demonstrated in Phase III trials. However, low concentrations combined with other risk factors have been associated with an increased risk of virologic failure. This study aims to verify whether drug concentrations measured in a real-world setting are consistent with those previously reported.

Methods

SHCS-879 is a nationwide observational study within the Swiss HIV Cohort Study for the monitoring of people with HIV (PWH) on long-acting cabotegravir plus rilpivirine. Samples were collected from March 2022 to March 2023.

Findings

Overall, 725 samples were obtained from 186 PWH. Our data show a large inter-individual variability in cabotegravir and rilpivirine concentrations, with some individuals exhibiting repeatedly low concentrations. Rilpivirine trough concentrations were consistent with those from Phase III trials, while cabotegravir concentrations were lower. The first concentrations quartile was only slightly above the target of 664 ng/mL. Exploratory statistical analyses found 35% (p < 0·01) lower cabotegravir trough in males compared to females. Overall, 172 PWH (92%) remained suppressed and three experienced virologic failures (1·6%), of those, two had sub-optimal drug exposure. No association was found between low trough levels and detectable viral load.

Interpretation

Real-world cabotegravir concentrations are substantially lower than previously reported. However, these concentrations appear sufficient to ensure sustained virological suppression in almost every PWH. These reassuring data challenge the rather conservative thresholds adopted to date, which may raise unnecessary concerns. Yet, our study reveals that some PWH have repeatedly very low drug levels, for reasons that remain to be elucidated.

Funding

This work was funded by the Swiss National Science Foundation, grant number N◦ 324730_192449. This study received no support from pharmaceutical industries. This study was performed within the framework of the Swiss HIV Cohort Study, supported by the Swiss National Science Foundation (grant #201369), by SHCS project #879, and by the SHCS research foundation. The SHCS data were gathered by the Five Swiss University Hospitals, two Cantonal Hospitals, 15 affiliated hospitals and 36 private physicians (listed in http://www.shcs.ch/180-health-care-providers).

Major revision version 12.0 of the European AIDS Clinical Society guidelines 2023

BACKGROUND

The European AIDS Clinical Society (EACS) guidelines were revised in 2023 for the 19th time, and all aspects of HIV care were updated.

KEY POINTS OF THE GUIDELINES UPDATE

Version 12.0 of the guidelines recommend the same six first-line treatment options for antiretroviral treatment (ART)-naïve adults as versions 11.0 and 11.1: tenofovir-based backbone plus an unboosted integrase inhibitor or doravirine; abacavir/lamivudine plus dolutegravir; or dual therapy with lamivudine or emtricitabine plus dolutegravir. The long-acting section has been expanded in the ART and drug-drug interaction (DDI) panels. Tables for preferred and alternative ART in children and adolescents have been updated, as has the section on prevention of vertical transmission, particularly with new guidance for breastfeeding. A new DDI table has been included for the ART and anti-infective drugs used for opportunistic infections, sexually transmitted infections, and other infectious conditions; lenacapavir has been included in all DDI tables. New sections on alcohol use and patient-reported outcome measures (PROMs) have been included in the comorbidity panel, in addition to updates on many relevant topics, such as new resource guidance for deprescribing in people with HIV. Other sections, including travel, cognitive impairment, cancer screening, sexual health, and diabetes have also been revised extensively. The algorithm for the management of acute hepatitis C virus infection has been removed, as current guidelines recommend immediate treatment of all people with recently acquired hepatitis C virus. Updates on vaccination for hepatitis B virus and recommendations for simplification to tenofovir-free two-drug regimens in people with isolated anti-hepatitis B core antibodies are provided. In the opportunistic infections and COVID-19 panel, guidance on the management of COVID-19 in people with HIV has been updated according to the most up-to-date evidence, and a new section on monkeypox has been added.

CONCLUSIONS

In 2023, the EACS guidelines were updated extensively and now include several new sections. The recommendations are available as a free app, in interactive web format, and as a pdf online.

Long-acting combination of cabotegravir plus rilpivirine: A picture of potential eligible and ineligible HIV-positive individuals from the Italian ARCA cohort

OBJECTIVES

We aimed to evaluate the prevalence and characteristics of people living with HIV (PLWH) eligible for the long-acting injectable (LAI) regimen with cabotegravir (CAB) and rilpivirine (RPV), in comparison with ineligible individuals.

METHODS

This was an observational, cross-sectional study from the ARCA cohort, including virologically suppressed PLWH with at least one genotypic resistance testing (GRT) for reverse transcriptase and integrase from plasma and/or PBMCs. Eligibility criteria for LAI CAB+RPV were: negative HBsAg, absence of previous virological failures and/or resistance-associated mutations for non-nucleoside reverse transcriptase inhibitors (NNRTIs) and/or integrase strand transfer inhibitors. Potential differences between eligible and ineligible individuals were investigated by univariable and multivariable analyses.

RESULTS

A total of 514 individuals were included: 377 (73.3%) were male, median age was 51 (IQR: 43-58), on ART for 9 years (IQR: 4-17), virologically suppressed for 63 months (IQR: 35-105). Eligible individuals for CAB+RPV were 229 (44.5%, 95%CI: 40.8-48.8); compared with ineligible individuals, they received a lower number of previous regimens (aOR 0.76, 95% CI 0.71-0.83, P < 0.001) and were on current NNRTIs (aOR 2.16, 95% CI 1.38-3.37, P = 0.001).

CONCLUSIONS

Less than half of virologically suppressed PLWH in the ARCA cohort were potentially eligible for CAB+RPV. They seem to be "less complicated" with shorter exposure to ART and preferably already on NNRTIs.

Efficacy, safety, and tolerability of switching to long-acting cabotegravir plus rilpivirine versus continuing fixed-dose bictegravir, emtricitabine, and tenofovir alafenamide in virologically suppressed adults with HIV, 12-month results (SOLAR): a randomised, open-label, phase 3b, non-inferiority trial

BACKGROUND

Cabotegravir plus rilpivirine is the only approved complete long-acting regimen for the maintenance of HIV-1 virological suppression dosed every 2 months. The SOLAR study aimed to compare long-acting cabotegravir plus rilpivirine every 2 months with continued once-daily bictegravir, emtricitabine, and tenofovir alafenamide for the maintenance of HIV-1 virological suppression in adults living with HIV.

METHODS

SOLAR is a randomised, open-label, multicentre, phase 3b, non-inferiority study. The study was done in 118 centres across 14 countries. Participants with HIV-1 RNA less than 50 copies per mL were randomly assigned (2:1), stratified by sex at birth and BMI, to either long-acting cabotegravir (600 mg) plus rilpivirine (900 mg) dosed intramuscularly every 2 months or to continue daily oral bictegravir (50 mg), emtricitabine (200 mg), and tenofovir alafenamide (25 mg). Participants randomly assigned to long-acting therapy had a choice to receive cabotegravir (30 mg) plus rilpivirine (25 mg) once daily as an optional oral lead-in for approximately 1 month. The primary efficacy endpoint was the proportion of participants with virological non-response (HIV-1 RNA ≥50 copies per mL; the US Food and Drug Administration snapshot algorithm, 4% non-inferiority margin; modified intention-to-treat exposed population) at month 11 (long-acting start with injections group) and month 12 (long-acting with oral lead-in group and bictegravir, emtricitabine, and tenofovir alafenamide group). The study is registered with ClinicalTrials.gov, NCT04542070, and is ongoing.

FINDINGS

837 participants were screened between Nov 9, 2020, and May 31, 2021, and 687 were randomly assigned to switch treatment or continue existing treatment. Of 670 participants (modified intention-to-treat exposed population), 447 (67%) switched to long-acting therapy (274 [61%] of 447 start with injections; 173 [39%] of 447 with oral lead-in) and 223 (33%) continued bictegravir, emtricitabine, and tenofovir alafenamide. Baseline characteristics were similar; median age was 37 years (range 18-74), 118 (18%) of 670 were female sex at birth, 207 (31%) of 670 were non-White, and median BMI was 25·9 kg/m2 (IQR 23·3-29·5). At month 11-12, long-acting cabotegravir plus rilpivirine showed non-inferior efficacy versus bictegravir, emtricitabine, and tenofovir alafenamide (HIV-1 RNA ≥50 copies per mL, five [1%] of 447 vs one [<1%] of 223), with an adjusted treatment difference of 0·7 (95% CI -0·7 to 2·0). Excluding injection site reactions, adverse events and serious adverse events were similar between groups. No treatment-related deaths occurred. More long-acting group participants had adverse events leading to withdrawal (25 [6%] of 454 vs two [1%] of 227). Injection site reactions were reported by 316 (70%) of 454 long-acting participants; most (98%) were grade 1 or 2.

INTERPRETATION

These data support the use of long-acting cabotegravir plus rilpivirine dosed every 2 months as a complete antiretroviral regimen that has similar efficacy to a commonly used integrase strand transfer inhibitor-based first-line regimen, while addressing unmet psychosocial issues associated with daily oral treatment.

FUNDING

ViiV Healthcare.

Global HIV control: is the glass half empty or half full?

The massive scale-up of HIV treatment and prevention over the past two decades has resulted in important reductions in new infections and mortality globally. Reduction in HIV incidence, however, has been unequal, with worsening epidemics in regions where the reach and scale of HIV control programmes have been insufficient, especially in eastern Europe, central Asia, the Middle East, north Africa, and Latin America where HIV epidemics are concentrated among key populations, including people who inject drugs, men who have sex with men, transgender people, and some minority racial and ethnic groups. The global state of the HIV pandemic highlights disparities in HIV control efforts and provides a roadmap for what should be done, including investment to better implement the effective HIV prevention and treatment tools that are available, but whose adoption and scale-up are not yet sufficient to get us close to an AIDS-free generation. To achieve the full potential of global HIV control, we call for urgent, evidence-informed implementation at scale of our existing and novel HIV prevention and treatment strategies in ways that are better, faster, more efficient, and cost-effective, especially in key populations and regions where the HIV pandemic continues to expand.