Long-acting cabotegravir plus rilpivirine for treatment in adults with HIV-1 infection: 96-week results of the randomised, open-label, phase 3 FLAIR study

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

BACKGROUND

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.

METHODS

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.

FINDINGS

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).

INTERPRETATION

Long-acting therapy had non-inferior efficacy compared with oral therapy, with a good safety profile, and can be considered for African treatment programmes.

FUNDING

Janssen.

Simultaneous quantification of five antiretrovirals in human tissues using ultra-high performance liquid chromatography-tandem mass spectrometry methods for therapeutic drug monitoring at the sites of action

Although antiretroviral therapy (ART) is highly effective for the treatment of HIV-1 infection to suppress virus in the blood, HIV persists in tissues. HIV persistence in the tissues is due to numerous factors, and one of those factors are antiretroviral (ARV) concentrations. ARV concentrations in tissues must be adequate to suppress HIV at the sites of action. While therapeutic drug monitoring in the plasma is well-known, drug monitoring in the tissues provides local assessments of adequate ARV exposure to prevent localized HIV resistance formation. Towards these efforts, we validated an ultra-high performance liquid chromatography-mass spectrometry (UHPLC-MS/MS) method in human tissues (cervical, rectal, and vaginal tissues) for the simultaneous quantification of five ARVs: bictegravir, cabotegravir, dolutegravir, doravirine, and raltegravir. For this assay, protein precipitation with acetonitrile with stable, isotopically-labeled internal standards followed by supernatant pre-concentration was performed. Analyte separation was accomplished using a multistep UPLC gradient mixture of 0.1 % formic acid in water (A) and acetonitrile (B) with a Waters Cortecs T3 (2.1x100 mm) column. The assay was extensively validated as per the United States Food and Drug Administration Bioanalytical Method Validation Guidance over a clinically observed range (0.05-50 ng/mL) with superb linearity (R2 > 0.99 across all ARVs). The assay run time was 8.5 min. This analytical method achieves appropriate performance of trueness (85.5-107.4 %), repeatability, and precision (CV < 15 %). Our method will be employed for the therapeutic monitoring of guideline-recommended ARVs in human tissues for monitoring therapeutic efficacy in HIV treatment and prevention research efforts.

Tools Needed to Support Same-Day Diagnosis and Treatment of Current Hepatitis C Virus Infection

The current multiday diagnosis and treatment paradigm for hepatitis C virus (HCV) infection results in far fewer patients receiving treatment with direct-acting antiviral agents than those with diagnosed HCV infection. To achieve HCV elimination, a paradigm shift in access to HCV treatment is needed from multiday testing and treatment algorithms to same-day diagnosis and treatment. This shift will require new tools, such as point-of-care (POC) antigen tests or nucleic acid tests for HCV and hepatitis B virus (HBV) and nucleic acid tests for human immunodeficiency virus (HIV) that do not require venous blood. This shift will also require better use of existing resources, including expanded access to HCV treatment and available POC tests, novel monitoring approaches, and removal of barriers to approval. A same-day diagnosis and treatment paradigm will substantially contribute to HCV elimination by improving HCV treatment rates and expanding access to treatment in settings where patients have brief encounters with healthcare.

Evaluation of the prevention of mother-to-child transmission of HIV programs at the second immunization visit in Burkina Faso and Zambia

OBJECTIVE

Our study aimed to assess the PMTCT indicators in Burkina Faso and Zambia using a patient-orientated innovative strategy based on the second visit in the Expanded Program on Immunization (EPI-2) visit at 6-8 weeks.

DESIGN

This was a cross sectional study.

METHODS

We assessed women attending EPI-2 at primary healthcare facilities in Burkina Faso and Zambia with their children about their exposure to PMTCT interventions. For women living with HIV (WLHIV), viral load was measured and their children were tested for HIV DNA using point of care devices.

RESULTS

Overall, 25 093 were enrolled from Burkina Faso and 8961 women from Zambia. Almost, all women attended at least one antenatal care visit. Among those aware of their HIV-positive status, 95.8 and 99.2% were on antiretroviral therapy (ART) in Burkina Faso and Zambia, respectively. Among WLHIV on ART, 75 and 79.2% achieved a viral load suppression (viral load <1000 copies/ml) in Burkina Faso and Zambia, respectively. Infant postnatal prophylaxis was administered from birth until EPI-2 to 60.9 and 89.7% of HIV-exposed children in Burkina Faso and Zambia, respectively. In Burkina Faso, only 60 of 192 (31.3%) of HIV-exposed children were sampled at day 42 for early infant diagnosis (EID) and 3 (1.6%) received a result by EPI-2. In Zambia, these figures were 879 of 1465 (64.0%) and 9.9% (145/1465), respectively for HIV-exposed children sampled at birth.

CONCLUSION

This evaluation strategy at EPI-2 visit could strengthen program monitoring and help identifying gaps to be addressed on the last mile towards elimination of MTCT of HIV.

Feasibility of Implementing a Low-Barrier Long-Acting Injectable Antiretroviral Program for HIV Treatment and Prevention for People Experiencing Homelessness

BACKGROUND

Long-acting (LA) antiretrovirals may provide meaningful benefit to people who use drugs and people experiencing homelessness (PEH) who face disproportionate structural and psychosocial barriers in adhering to daily oral HIV antiretroviral therapy or pre-exposure prophylaxis (PrEP), but their use in these populations has not been studied.

SETTING

The Maria X. Martinez Health Resource Center is a low-barrier (eg, no appointment) community-based clinic serving San Francisco PEH.

METHODS

A multidisciplinary care model with robust monitoring and outreach support was developed to provide LA antiretroviral therapy (ART) and LA-PrEP to eligible patients experiencing difficulties adhering to oral antiretrovirals. Feasibility was assessed by evaluating the rates of HIV viremia and on-time injections among patients receiving LA antiretrovirals over the first 24 months of program implementation.

RESULTS

Between November 2021 and November 2023, 33 patients initiated LA-ART or LA-PrEP (median age, 37 years; 27% transgender/nonbinary; 73% non-White; 27% street homeless; 52% sheltered homeless; 30% with opioid use disorder; 82% with methamphetamine use disorder). Among 18 patients with HIV, 14 initiated LA-ART injections with detectable viremia (median CD4 count, 340 cells/mm 3 ; mean log 10 viral load, 3.53; SD, 1.62), 8 had never previously been virally suppressed, and all but 1 achieved or maintained virologic suppression (mean, 9.67 months; SD, 8.30). Among 15 LA-PrEP patients, all remained HIV negative (mean, 4.73 months; SD, 2.89). Of 224 total injections administered, 8% were delayed >7 days.

DISCUSSION

The implementation of LA antiretrovirals is feasible in low-barrier, highly supportive clinical settings serving vulnerable PEH. Expansion of such programs will be critical in ending the HIV epidemic.

Favorable Virological Outcome, Characteristics of Injection Site Reactions, Decrease in Renal Function Biomarkers in Asian People with HIV Receiving Long-Acting Cabotegravir Plus Rilpivirine

Long-acting cabotegravir plus rilpivirine has revolutionized the concept of antiretroviral therapy, but as the causes of virological failure and satisfaction can depend on patient background, real-world data are needed. In this single-center study, we reviewed clinical records of people with HIV (PWH) who received injectable cabotegravir plus rilpivirine between June 2022 and January 2023. We assessed virological and safety outcomes, including injection site reactions (ISRs) and changes in serum creatinine and cystatin C. Seventy-four patients were included. There were no virological failures. Approximately 80% of individuals achieved HIV-RNA undetectable in all visits up to 14 months (median 13 months) after switching. Pain upon injection was significantly more common at the rilpivirine injection site, while delayed pain was significantly more common at the cabotegravir injection site. The serum creatinine (mean difference -0.12 mg/dL, p < .0001) and the cystatin C (mean difference -0.077 mg/dL, p < .0001) decreased significantly after switching, and in multivariable regression analysis, baseline characteristics did not affect the decrease in these renal function markers. Long-acting cabotegravir plus rilpivirine showed excellent antiviral efficacy and safety in PWH in Japan. ISRs were characterized differently at the cabotegravir and rilpivirine injection sites. Although cystatin C showed decrease after the regimen switch, further confirmation is needed whether cabotegravir plus rilpivirine can improve renal function.

Patient Education and Decision Support for Long-Acting Injectable HIV Antiretroviral Therapy: Protocol for Tool Development and Pilot Testing with Ryan White HIV/AIDS Program Medical Case Management Programs in New York

BACKGROUND

Long-acting injectable (LAI) HIV antiretroviral therapy (ART) presents a major opportunity to facilitate and sustain HIV viral suppression, thus improving health and survival among people living with HIV and reducing the risk of onward transmission. However, realizing the public health potential of LAI ART requires reaching patients who face barriers to daily oral ART adherence and thus can clinically benefit from alternative treatment modalities. Ryan White HIV/AIDS Program Part A medical case management (MCM) programs provide an array of services to address barriers to HIV care and treatment among economically and socially marginalized people living with HIV. These programs have demonstrated effectiveness in improving engagement along the continuum of care, but findings of limited program impact on durable viral suppression highlight the need to further innovate and hone strategies to support long-term ART adherence.

OBJECTIVE

This study aims to adapt and expand Ryan White MCM service strategies to integrate LAI ART regimen options, with the larger goal of improving health outcomes in the populations that could most benefit from alternatives to daily oral ART regimens.

METHODS

In 3 phases of work involving patient and provider participants, this study uses role-specific focus groups to elicit perceptions of LAI versus daily oral ART; discrete choice experiment (DCE) surveys to quantify preferences for different ART delivery options and related supports; and a nonrandomized trial to assess the implementation and utility of newly developed tools at 6 partnering Ryan White HIV/AIDS Program Part A MCM programs based in urban, suburban, and semirural areas of New York. Findings from the focus groups and DCEs, as well as feedback from advisory board meetings, informed the design and selection of the tools: a patient-facing, 2-page fact sheet, including frequently asked questions and a side-by-side comparison of LAI with daily oral ART; a patient-facing informational video available on YouTube (Google Inc); and a patient-provider decision aid. Implementation outcomes, measured through provider interviews, surveys, and service reporting, will guide further specification of strategies to integrate LAI ART options into MCM program workflows.

RESULTS

The study was funded in late April 2021 and received approval from the institutional review board in May 2021 under protocol 20-096. Focus groups were conducted in late 2021 (n=21), DCEs ran from June 2022 to January 2023 (n=378), and tools for piloting were developed by May 2023. The trial (May 2023 through January 2024) has enrolled >200 patients.

CONCLUSIONS

This study is designed to provide evidence regarding the acceptability, feasibility, appropriateness, and utility of a package of patient-oriented tools for comparing and deciding between LAI ART and daily oral ART options. Study strengths include formative work to guide tool development, a mixed methods approach, and the testing of tools in real-world safety-net service settings.

TRIAL REGISTRATION

Clinicaltrials.gov NCT05833542; https://clinicaltrials.gov/study/NCT05833542.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/56892.

Asian participants' experience in phase 3/3b studies of long-acting cabotegravir and rilpivirine: Efficacy, safety, pharmacokinetic, and virological outcomes through week 96

OBJECTIVES

Cabotegravir + rilpivirine (CAB + RPV) dosed monthly or every 2 months is the first complete long-acting (LA) regimen recommended by treatment guidelines for the maintenance of HIV-1 virological suppression. This post hoc analysis summarizes outcomes for Asian participants through week 96.

METHODS

Data from Asian participants naive to CAB + RPV randomized to receive dosing every 4 weeks (Q4W) or every 8 weeks (Q8W) in the FLAIR (NCT02938520) and ATLAS-2M (NCT03299049) phase 3/3b studies were pooled. The proportion of participants with plasma HIV-1 RNA ≥50 and <50 copies/mL (per FDA Snapshot algorithm), incidence of confirmed virological failure (CVF; two consecutive HIV-1 RNA ≥200 copies/mL), pharmacokinetics, safety, and tolerability through week 96 were assessed.

RESULTS

Overall, 41 Asian participants received CAB + RPV (Q8W, n = 17; Q4W, n = 24). At week 96, 83% (n = 34/41) of participants maintained HIV-1 RNA <50 copies/mL, none had HIV-1 RNA ≥50 copies/mL, and 17% (n = 7/41) had no virological data. No Asian participant met the CVF criterion. Drug-related adverse events occurred in 44% (n = 18/41) of participants; none were Grade ≥3. All injection site reactions were Grade 1 or 2; median duration was 2 days and most resolved within 7 days (90%, n = 390/435). CAB and RPV trough concentrations remained well above their respective protein-adjusted 90% inhibitory concentrations (CAB, 0.166 μg/mL; RPV, 12 ng/mL) through week 96.

CONCLUSIONS

CAB + RPV LA demonstrated high efficacy, with no participants having CVF, and an acceptable safety profile in Asian participants through week 96. These data support CAB + RPV LA as a complete regimen for the maintenance of HIV-1 virological suppression in Asian individuals.

Implementation of a Pharmacist-Led, Long-Acting, Injectable Cabotegravir/Rilpivirine Program for HIV-1 at Health System-Based Clinics in the New York Metropolitan Area

Long-acting cabotegravir/rilpivirine (LA-CAB/RPV) is the first complete injectable antiretroviral for patients living with HIV. To facilitate patient access to long-acting injectable treatment, a system-wide, pharmacist-led, LA-CAB/RPV transition program was developed at four health system-based New York clinics. Provider referrals were received across four clinics between January 22nd, 2021, and December 31st, 2022. All referrals were evaluated by a pharmacist for clinical eligibility and medication access. The primary outcome was the treatment retention rate defined as the percentage of patients who remained on LA-CAB/RPV at 3 months post-transition. A total of 171 referrals were received, with 73 patients (43%) initiating LA-CAB/RPV. Baseline demographics included a median age of 38 years, 81% patients were male, 41% were African American, and 49% had commercial insurance coverage. The treatment retention rate was 90% at 3 months post-transition. By the end of the study period, 84% of patients who transitioned remained on LA-CAB/RPV. Treatment was discontinued due to reasons such as viral breakthrough (4%), emergence of mutations (4%), and intolerable side effects (4%). Injection site reactions were commonly reported (51%), but only resulting in treatment discontinuation for one patient. A pharmacist-led program can transition a diverse population of patients living with HIV to LA-CAB/RPV. Results from this study further add to clinical experiences with LA-CAB/RPV, demonstrating real-world treatment retention despite more frequent clinic visits for patients.

People with HIV pioneers of injectable cabotegravir and rilpivirine long acting in Italy: who are they?

Injectable cabotegravir and rilpivirine long-acting therapy is a revolutionary new antiretroviral treatment (ART) option for HIV infection in virologically suppressed adults on a stable ART. The aim of this study from SCOLTA multicenter observational prospective database is to describe the first people living with HIV (PWH) who started this regimen in Italy, assessing adherence to eligibility criteria, describing clinical-epidemiological characteristics compared to registration trials-population and describe early treatment-discontinuations.

Polymer Delivery Systems for Long-Acting Antiretroviral Drugs

The success of long-acting (LA) drug delivery systems (DDSs) is linked to their biocompatible polymers. These are used for extended therapeutic release. For treatment or prevention of human immune deficiency virus type one (HIV-1) infection, LA DDSs hold promise for improved regimen adherence and reduced toxicities. Current examples include Cabenuva, Apretude, and Sunlenca. Each is safe and effective. Alternative promising DDSs include implants, prodrugs, vaginal rings, and microarray patches. Each can further meet patients' needs. We posit that the physicochemical properties of the formulation chemical design can optimize drug release profiles. We posit that the strategic design of LA DDS polymers will further improve controlled drug release to simplify dosing schedules and improve regimen adherence.

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.

Predictors of Post-switch Viremia in People With HIV on Injectable Cabotegravir/Rilpivirine

BACKGROUND

Predictors of virologic failure in those receiving long-acting injectable (LAI) cabotegravir/rilpivirine (CAB/RPV) have been evaluated; however, factors associated with low-level viremia, including blips and persistent low-level viremia (pLLV), are not well-described.

METHODS

A retrospective cohort study was performed using data from April 2021 through December 2022. Inclusion criteria included treatment with CAB/RPV for at least 3 months, availability of pre- and postswitch HIV RNA values, HIV RNA value of <200 copies/mL (cpm) at the time of switch to CAB/RPV, and at least 1 postswitch HIV RNA collected >21 days after the start of CAB/RPV. Outcomes included incidence of HIV RNA ≥20, ≥50, and ≥200 cpm after switch and factors associated with detectable HIV RNA after switch.

RESULTS

The median duration of follow-up among 144 participants was 287 days. After switching to CAB/RPV, occurrences of at least 1 HIV RNA ≥20, ≥50, and ≥200 cpm after switch were 34.7%, 15.3%, and 2.8%, respectively. Those with pLLV before switch were significantly more likely to have detectable HIV RNA after switch [hazard ratio 24.39 (8.71-68.34)], and 44.4% of those with pLLV before switch continued with pLLV after switch to LAI CAB/RPV. Body mass index, late injection, and monthly versus every two-month dosing were not associated with detectable viremia after switch.

CONCLUSIONS

Despite virologic suppression at the time of switch and the perceived adherence benefits, participants still experienced blips or pLLV after switch to LAI CAB/RPV. Having detectable HIV RNA on oral therapy before switch was associated with detectable HIV RNA after switching.

Improving Adherence to the Target Window for Cabotegravir + Rilpivirine Long-Acting Injections Through the CHORUS™ App and Web Portal: A Cluster Randomized Trial

BACKGROUND

We evaluated the impact of the CHORUS™ app on adherence to the cabotegravir and rilpivirine long-acting injectable (CAB + RPV LAI) monthly injections schedule.

METHODS

Healthcare centers (HCCs) were randomized to access CHORUS™ CAB + RPV LAI features (intervention) or not (control) from 01OCT2021-31JAN2022. Target window adherence (maintenance injections ≤7 days before/after target day) was assessed with multivariate logistic regression (generalized estimating equations).

RESULTS

CAB + RPV LAI was administered to 188 and 79 individuals at intervention and control HCCs, respectively. Intervention was not associated with improved target window adherence (adjusted odds ratio: 0.61 [95% CI: 0.30-1.25]). However, app use was associated with increased odds of adherence compared to no app use among all intervention HCCs (2.98 [1.26-7.06]) and at smaller HCCs (3.58 [1.31-9.80]).

CONCLUSIONS

While access to CHORUS™ CAB + RPV LAI features did not improve target window adherence, app use did, especially at smaller HCCs which may not have established LAI management procedures.

TRIAL REGISTRATION

https://clinicaltrials.gov/show/NCT04863261.

Advancements in Cell-Based Therapies for HIV Cure

The treatment of human immunodeficiency virus (HIV-1) has evolved since the establishment of combination antiretroviral therapy (ART) in the 1990s, providing HIV-infected individuals with approaches that suppress viral replication, prevent acquired immunodeficiency syndrome (AIDS) throughout their lifetime with continuous therapy, and halt HIV transmission. However, despite the success of these regimens, the global HIV epidemic persists, prompting a comprehensive exploration of potential strategies for an HIV cure. Here, we offer a consolidated overview of cell-based therapies for HIV-1, focusing on CAR-T cell approaches, gene editing, and immune modulation. Persistent challenges, including CAR-T cell susceptibility to HIV infection, stability, and viral reservoir control, underscore the need for continued research. This review synthesizes current knowledge, highlighting the potential of cellular therapies to address persistent challenges in the pursuit of an HIV cure.

Characterization of Human Immunodeficiency Virus-1 Transmission Clusters and Transmitted Drug-Resistant Mutations in Croatia from 2019 to 2022

Molecular epidemiology of HIV-1 infection is challenging due to the highly diverse HIV-genome. We investigated the genetic diversity and prevalence of transmitted drug resistance (TDR) followed by phylogenetic analysis in 270 HIV-1 infected, treatment-naïve individuals from Croatia in the period 2019-2022. The results of this research confirmed a high overall prevalence of TDR of 16.7%. Resistance to nucleoside reverse transcriptase inhibitors (NRTIs), non-nucleoside RTIs (NNRTIs), and protease inhibitors (PIs) was found in 9.6%, 7.4%, and 1.5% of persons, respectively. No resistance to integrase strand-transfer inhibitors (INSTIs) was found. Phylogenetic analysis revealed that 173/229 sequences (75.5%) were part of transmission clusters, and the largest identified was T215S, consisting of 45 sequences. Forward transmission was confirmed in several clusters. We compared deep sequencing (DS) with Sanger sequencing (SS) on 60 randomly selected samples and identified additional surveillance drug resistance mutations (SDRMs) in 49 of them. Our data highlight the need for baseline resistance testing in treatment-naïve persons. Although no major INSTIs were found, monitoring of SDRMs to INSTIs should be continued due to the extensive use of first- and second-generation INSTIs.

Integrase inhibitors: current protagonists in antiretroviral therapy

Since HIV was identified as the etiological agent of AIDS, there have been significant advances in antiretroviral therapy (ART) that has reduced morbidity/mortality. Still, the viral genome's high mutation rate, suboptimal ART regimens, incomplete adherence to therapy and poor control of the viral load generate variants resistant to multiple drugs. Licensing over 30 anti-HIV drugs worldwide, including integrase inhibitors, has marked a milestone since they are potent and well-tolerated drugs. In addition, they favor a faster recovery of CD4+ T cells. They also increase the diversity profile of the gut microbiota and reduce inflammatory markers. All of these highlight the importance of including them in different ART regimens.

Cabotegravir + Rilpivirine Long-Acting Injections for HIV Treatment in the US: Real World Data from the OPERA Cohort

INTRODUCTION

The first complete long-acting antiretroviral therapy (ART) regimen, cabotegravir + rilpivirine long-acting (CAB + RPV LA) injectable, was approved in the US for HIV-1 treatment in individuals on a stable antiretroviral regimen with a viral load < 50 copies/mL, no treatment failure history, and no resistance to either cabotegravir or rilpivirine. We describe injection schedule adherence and virologic effectiveness of CAB + RPV LA in routine clinical care in the US.

METHODS

From the OPERA® cohort, all adults with HIV who received their first CAB + RPV LA injection and ≥ 1 continuation injections between 21 January 2021 and 15 March 2022 were included. The injection target date was updated monthly and set to the same date of the month as the previous injection. Continuation injections administered within 7 days before or after the target date were considered on time, as per the label. Virologic undetectability (viral load < 50 copies/mL), suppression (viral load < 200 copies/mL), and confirmed virologic failure (2 consecutive viral loads ≥ 200 copies/mL or 1 viral load ≥ 200 copies/mL followed by discontinuation) were described among individuals with a viral load < 50 copies/mL at initiation and ≥ 1 follow-up viral load.

RESULTS

Among 321 individuals on CAB + RPV LA, 90% of the continuation injections were administered on time (within ± 7 days of the target date). Of the 237 individuals with a viral load < 50 copies/mL at initiation and ≥ 1 follow-up viral load, nearly all were undetectable (95%) or suppressed (99%) at their last viral load measurement, 96% maintained virologic suppression with all measured viral loads < 200 copies/mL, and four confirmed virologic failures were observed. Injection delays were infrequent, and did not affect virologic outcomes over the short term.

CONCLUSION

In this large US cohort, most monthly CAB + RPV LA injections were administered on time and high levels of virologic control were achieved. These results suggest that CAB + RPB LA injectable can be administered effectively during routine clinical care.

Considerations for long-acting antiretroviral therapy in older persons with HIV

People with HIV (PWH) can now enjoy longer, healthier lives due to safe and highly effective antiretroviral therapy (ART), and improved care and prevention strategies. New drug formulations such as long-acting injectables (LAI) may overcome some limitations and issues with oral antiretroviral therapy and strengthen medication adherence. However, challenges and questions remain regarding their use in aging populations. Here, we review unique considerations for LAI-ART for the treatment of HIV in older PWH, including benefits, risks, pharmacological considerations, implementation challenges, knowledge gaps, and identify factors that may facilitate uptake of LA-ART in this population.

Clair M, Polli JW, Vanveggel S, Vandermeulen K, D’Amico R, Garges HP, Zolopa A, Spreen WR, van Wyk J, Cutrell AG. 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

BACKGROUND

Previously reported post hoc multivariable analyses exploring predictors of confirmed virologic failure (CVF) with cabotegravir + rilpivirine long-acting (CAB + RPV LA) were expanded to include data beyond week 48, additional covariates, and additional participants.

METHODS

Pooled data from 1651 participants were used to explore dosing regimen (every 4 or every 8 weeks), demographic, viral, and pharmacokinetic covariates as potential predictors of CVF. Prior dosing regimen experience was accounted for using 2 populations. Two models were conducted in each population-baseline factor analyses exploring factors known at baseline and multivariable analyses exploring baseline factors plus postbaseline model-predicted CAB/RPV trough concentrations (4 and 44 weeks postinjection). Retained factors were evaluated to understand their contribution to CVF (alone or in combination).

RESULTS

Overall, 1.4% (n = 23/1651) of participants had CVF through 152 weeks. The presence of RPV resistance-associated mutations, human immunodeficiency virus-1 subtype A6/A1, and body mass index ≥30 kg/m2 were associated with an increased risk of CVF (P < .05 adjusted incidence rate ratio), with participants with ≥2 of these baseline factors having a higher risk of CVF. Lower model-predicted CAB/RPV troughs were additional factors retained for multivariable analyses.

CONCLUSIONS

The presence of ≥2 baseline factors (RPV resistance-associated mutations, A6/A1 subtype, and/or body mass index ≥30 kg/m2) was associated with increased CVF risk, consistent with prior analyses. Inclusion of initial model-predicted CAB/RPV trough concentrations (≤first quartile) did not improve the prediction of CVF beyond the presence of a combination of ≥2 baseline factors, reinforcing the clinical utility of the baseline factors in the appropriate use of CAB + RPV LA.

Assessing readiness to implement long-acting injectable HIV antiretroviral therapy: provider and staff perspectives

BACKGROUND

Long-acting injectable antiretroviral therapy (LAI-ART) represents the next innovation in HIV therapy. Pre-implementation research is needed to develop effective strategies to ensure equitable access to LAI-ART to individuals living with HIV.

METHODS

We conducted focus group discussions (FGDs) with providers and staff affiliated with HIV clinics in San Francisco, Chicago, and Atlanta to understand barriers to and facilitators of LAI-ART implementation. Participants also completed a short survey about implementation intentions. FGDs were held via video conference, recorded, transcribed, and thematically analyzed using domains associated with the Consolidated Framework for Implementation Research (CFIR).

RESULTS

Between September 2020 and April 2021, we led 10 FDGs with 49 participants, of whom ~60% were prescribing providers. Organizational readiness for implementing change was high, with 85% agreeing to being committed to figuring out how to implement LAI-ART. While responses were influenced by the unique inner and outer resources available in each setting, several common themes, including implementation mechanisms, dominated: (1) optimism and enthusiasm about LAI-ART was contingent on ensuring equitable access to LAI-ART; (2) LAI-ART shifts the primary responsibility of ART adherence from the patient to the clinic; and (3) existing clinic systems require strengthening to meet the needs of patients with adherence challenges. Current systems in all sites could support the use of LAI-ART in a limited number of stable patients. Scale-up and equitable use would be challenging or impossible without additional personnel. Participants outlined programmatic elements necessary to realize equitable access including centralized tracking of patients, capacity for in-depth, hands-on outreach, and mobile delivery of LAI-ART. Sites further specified unknown logistical impacts on implementation related to billing/payer source as well as shipping and drug storage.

CONCLUSIONS

Among these HIV care sites, clinic readiness to offer LAI-ART to a subset of patients is high. The main challenges to implementation include concerns about unequal access and a recognition that strengthening the clinic system is critical.

The New Era of Long-Acting Antiretroviral Therapy: When and Why to Make the Switch

PURPOSE OF REVIEW

Despite the availability of safe and effective oral combination antiretroviral therapy, barriers to maintaining viral suppression remain a challenge to ending the HIV epidemic. Long-acting injectable antiretroviral therapy was developed as an alternative to daily oral therapy. This review summarizes the current literature on the efficacy of long-acting cabotegravir plus rilpivirine for the treatment of HIV-1, reasons to switch to injectable therapy, and barriers to switching.

RECENT FINDINGS

Long-acting cabotegravir plus rilpivirine is safe and effective in maintaining HIV-1 virologic suppression. Ideal candidates for switching to long-acting cabotegravir plus rilpivirine are virologically suppressed on oral regimens with good adherence and no history of virologic failure or baseline resistance. Indications to switch to injectable therapy include patient preference, the potential for improved adherence, and avoidance of adverse effects. Implementation research is needed to assess and overcome system barriers. Long-acting cabotegravir plus rilpivirine is a novel alternative to oral antiretrovirals, with the potential to improve adherence and quality of life in people with HIV.

Prevention, treatment and cure of HIV infection

The development of antiretroviral therapy for the prevention and treatment of HIV infection has been marked by a series of remarkable successes. However, the efforts to develop a vaccine have largely failed, and efforts to discover a cure are only now beginning to gain traction. In this Review, we describe recent progress on all fronts - pre-exposure prophylaxis, vaccines, treatment and cure - and we discuss the unmet needs, both current and in the coming years. We describe the emerging arsenal of drugs, biologics and strategies that will hopefully address these needs. Although HIV research has largely been siloed in the past, this is changing, as the emerging research agenda is marked by multiple cross-discipline synergies and collaborations. As the limitations of antiretroviral drugs as a means to truly end the epidemic are becoming more apparent, there is a great need for continued efforts to develop an effective preventative vaccine and a scalable cure, both of which remain formidable challenges.

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.

HIV infection

The AIDS epidemic has been a global public health issue for more than 40 years and has resulted in ~40 million deaths. AIDS is caused by the retrovirus, HIV-1, which is transmitted via body fluids and secretions. After infection, the virus invades host cells by attaching to CD4 receptors and thereafter one of two major chemokine coreceptors, CCR5 or CXCR4, destroying the host cell, most often a T lymphocyte, as it replicates. If unchecked this can lead to an immune-deficient state and demise over a period of ~2-10 years. The discovery and global roll-out of rapid diagnostics and effective antiretroviral therapy led to a large reduction in mortality and morbidity and to an expanding group of individuals requiring lifelong viral suppressive therapy. Viral suppression eliminates sexual transmission of the virus and greatly improves health outcomes. HIV infection, although still stigmatized, is now a chronic and manageable condition. Ultimate epidemic control will require prevention and treatment to be made available, affordable and accessible for all. Furthermore, the focus should be heavily oriented towards long-term well-being, care for multimorbidity and good quality of life. Intense research efforts continue for therapeutic and/or preventive vaccines, novel immunotherapies and a cure.

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.

Study protocol: the ILANA study - exploring optimal implementation strategies for long-acting antiretroviral therapy to ensure equity in clinical care and policy for women, racially minoritised people and older people living with HIV in the UK - a qualitative multiphase longitudinal study design

INTRODUCTION

Cabotegravir and rilpivirine (CAB+RPV long-acting (LA)) is recommended as a treatment for HIV-1 allowing people living with HIV to receive 2 monthly injectable treatment, rather than daily pills. Providing injectable therapy in a system designed to provide and manage study participants on oral treatments poses logistical challenges namely how resources are used to accommodate patient preference within constrained health economies with capacity limitations. In this pragmatic multicentre study, we aim to understand the implementation of CAB-RPV-LA administration in two settings via mixed methods to explore perspectives of participants and the clinical team delivering CAB+RPV LA.

METHODS AND ANALYSIS

Women, racially minoritised people and older people are chronically under-represented in HIV clinical trials so the ILANA trial has set recruitment caps to ensure recruitment of 50% women, 50% ethnically diverse people and 30% over 50 years of age to include a more representative study population. Using a mixed-methods approach, the primary objective is to identify and evaluate the critical implementation strategies for CAB+RPV LA in both hospital and community settings. Secondary objectives include evaluating feasibility and acceptability of CAB+RPV LA administration at UK clinics and community settings from the perspective of HIV care providers, nurses and representatives at community sites, evaluating barriers to implementation, the utility of implementation strategies and adherence.

ETHICS AND DISSEMINATION

Ethical approval has been obtained from the Health Research Authority Research Ethics Committee (REC reference: 22/PR/0318). The dissemination strategy has been formulated with the SHARE Collaborative Community Advisory Board to maximise the impact of this work on clinical care and policy. This strategy draws on and leverages existing resources within the participating organisations, such as their academic infrastructure, professional relationships and community networks. The strategy will leverage the Public Engagement Team and press office to support dissemination of findings.

TRIAL REGISTRATION NUMBER

NCT05294159.

Impact of rilpivirine cross-resistance on long-acting cabotegravir-rilpivirine in low and middle-income countries

Baseline rilpivirine drug resistance mutations (DRMs) are a risk factor for virological failure in patients treated with long-acting cabotegravir and rilpivirine (CAB/RPV LA). We investigated rilpivirine cross-resistance in treatment-naive and experienced patients in South Africa. One in 10 treatment-naive patients and 74.5% of patients failing treatment presented with rilpivirine DRMs. Our data suggest targeted genotyping may be required for patients initiating CAB/RPV LA, which significantly complicates the currently used public health approach.

Long-Acting Antiretroviral Drug Therapy in Adolescents: Current Status and Future Prospects

Approximately 50% of human immunodeficiency virus (HIV)-infected adolescents fail to achieve complete viral suppression, largely due to nonadherence to their antiretroviral drug regimens. Numerous personal, financial, and societal barriers contribute to nonadherence, which may lead to the development of HIV drug resistance. Long-acting antiretroviral drugs hold the promise of improved adherence because they remove the need for swallowing one or more pills daily. Cabotegravir (an integrase strand transfer inhibitor) and rilpivirine (a non-nucleoside reverse transcriptase inhibitor) can now be intramuscularly co-administered to HIV-infected adolescents every 4-8 weeks if they are virologically suppressed and without resistance mutations to cabotegravir or rilpivirine. Adverse effects are few and non-severe. Widespread use of this complete antiretroviral therapy may be limited by drug costs, need for sites and skilled personnel who can administer the injections, and ethical challenges. Other long-acting medications and new antiretroviral therapy delivery systems are under active investigation and show great promise.

Two-drug regimens for HIV treatment

Combination therapy with three antiretroviral agents has been integral to successful HIV-1 treatment since 1996. Although the efficacy, adverse effects, and toxicities of contemporary three-drug regimens have improved, even the newest therapies have potential adverse effects. The use of two-drug regimens is one way to reduce lifetime exposure to antiretroviral drugs while maintaining the benefits of viral suppression. Multiple large, randomised trials have shown the virological non-inferiority of certain two-drug regimens versus three-drug comparators, including adverse effect differences that reflect known profiles of the antiretroviral drugs in the respective regimens. Two-drug combinations are now recommended in treatment guidelines and include the first long-acting antiretroviral regimen for the treatment of HIV-1. Recommended two-drug regimens differ in their risks for, and factors associated with, virological failure and emergent resistance. The tolerability, safety, metabolic profiles, and drug interactions of two-drug regimens also vary by the constituent drugs. No current two-drug regimen is recommended for people with chronic hepatitis B virus as none include tenofovir. Two-drug regimens have increased options for individualised care.

Genotypic correlates of resistance to the HIV-1 strand transfer integrase inhibitor cabotegravir

Cabotegravir (CAB) is an integrase strand transfer inhibitor (INSTI) formulated as a long-acting injectable drug approved for pre-exposure prophylaxis and use with a long acting rilpivirine formulation for therapy in patients with virological suppression. However, there has been no comprehensive review of the genetic mechanisms of CAB resistance. Studies reporting the selection of drug resistance mutations (DRMs) by CAB and the results of in vitro CAB susceptibility testing were reviewed. The impact of integrase mutations on CAB susceptibility was assessed using regularized regression analysis. The most commonly selected mutations in the 24 persons developing virological failure while receiving CAB included Q148R (n = 15), N155H (n = 7), and E138K (n = 5). T97A, G118R, G140 A/R/S, and R263K each developed in 1-2 persons. With the exception of T97A, G118R, and G140 A/R, these DRMs were also selected in vitro while G140R was selected in the SIV macaque model. Although these DRMs are similar to those occurring in persons receiving the related INSTI dolutegravir, Q148R was more likely to occur with CAB while G118R and R263K were more likely to occur with dolutegravir. Regularized regression analysis identified 14 DRMs significantly associated with reduced CAB susceptibility including six primary DRMs which reduced susceptibility on their own including G118R, Q148 H/K/R, N155H, and R263K, and eight accessory DRMs including M50I, L74 F/M, T97A, E138K, and G140 A/C/S. Isolates with Q148 H/K/R in combination with L74M, E138 A/K, G140 A/S, and N155H often had >10-fold reduced CAB susceptibility. M50I, L74M, and T97A are polymorphic mutations that alone did not appear to increase the risk of virological failure in persons receiving a CAB-containing regimen. Careful patient screening is required to prevent CAB from being used during active virus replication. Close virological monitoring is required to minimize CAB exposure to active replication to prevent the emergence of DRMs associated with cross-resistance to other INSTIs.

Barriers to Uptake of Long-Acting Antiretroviral Products for Treatment and Prevention of Human Immunodeficiency Virus (HIV) in High-Income Countries

Long-acting injectable antiretroviral therapy (LAI-ART) for the treatment and prevention of human immunodeficiency virus (HIV) holds great potential to shift treatment paradigms by offering an alternative to daily oral medication. However, significant challenges at the drug, patient, and system levels risk impeding the uptake and implementation of LAI-ART. This review aims to describe the known and anticipated barriers to uptake of LAI-ART in high-income countries, as well as the ongoing research addressing some of these barriers to improve the delivery and uptake of LAI-ART products.

The risk of drug resistance during long-acting antimicrobial therapy

The emergence of drug resistance during antimicrobial therapy is a major global health problem, especially for chronic infections like human immunodeficiency virus, hepatitis B and C, and tuberculosis. Sub-optimal adherence to long-term treatment is an important contributor to resistance risk. New long-acting drugs are being developed for weekly, monthly or less frequent dosing to improve adherence, but may lead to long-term exposure to intermediate drug levels. In this study, we analyse the effect of dosing frequency on the risk of resistance evolving during time-varying drug levels. We find that long-acting therapies can increase, decrease or have little effect on resistance, depending on the source (pre-existing or de novo) and degree of resistance, and rates of drug absorption and clearance. Long-acting therapies with rapid drug absorption, slow clearance and strong wild-type inhibition tend to reduce resistance caused by partially resistant strains in the early stages of treatment even if they do not improve adherence. However, if subpopulations of microbes persist and can reactivate during sub-optimal treatment, longer-acting therapies may substantially increase the resistance risk. Our results show that drug kinetics affect selection for resistance in a complicated manner, and that pathogen-specific models are needed to evaluate the benefits of new long-acting therapies.

Antiviral drugs

In this chapter, we have reviewed side effects reported with the use of antivirals for the treatment of the following infections: coronavirus disease 2019 (COVID-19), cytomegalovirus (CMV), hepatitis B virus (HBV), hepatitis C Virus (HCV), herpes simplex viruses 1 and 2 (HSV-1, -2), human immunodeficiency virus (HIV), and influenza virus. The search engines PUBMED, EMBASE and International Pharmaceutical Abstracts (IPA) were utilized to identify literature published between January 1, 2021 to December 31, 2021.

A clinical review of HIV integrase strand transfer inhibitors (INSTIs) for the prevention and treatment of HIV-1 infection

Integrase strand transfer inhibitors (INSTIs) have improved the treatment of human immunodeficiency virus (HIV). There are currently four approved for use in treatment-naïve individuals living with HIV; these include first generation raltegravir, elvitegravir, and second generation dolutegravir and bictegravir. The most recent INSTI, cabotegravir, is approved for (1) treatment of HIV infection in adults to replace current antiretroviral therapy in individuals who maintain virologic suppression on a stable antiretroviral regimen without history of treatment failure and no known resistance to its components and (2) pre-exposure prophylaxis in individuals at risk of acquiring HIV-1 infection. Cabotegravir can be administered intramuscularly as a monthly or bi-monthly injection depending on the indication. This long-acting combination has been associated with treatment satisfaction in clinical studies and may be helpful for individuals who have difficulty taking daily oral medications. Worldwide, second generation INSTIs are preferred for treatment-naïve individuals. Advantages of these INSTIs include their high genetic barrier to resistance, limited drug-drug interactions, excellent rates of virologic suppression, and favorable tolerability. Few INSTI resistance-associated mutations have been reported in clinical trials involving dolutegravir, bictegravir and cabotegravir. Other advantages of specific INSTIs include their use in various populations such as infants and children, acute HIV infection, and individuals of childbearing potential. The most common adverse events observed in clinical studies involving INSTIs included diarrhea, nausea, insomnia, fatigue, and headache, with very low rates of treatment discontinuation versus comparator groups. The long-term clinical implications of weight gain associated with second generation INSTIs dolutegravir and bictegravir warrants further study. This review summarizes key clinical considerations of INSTIs in terms of clinical pharmacology, drug-drug interactions, resistance, and provides perspective on clinical decision-making. Additionally, we summarize major clinical trials evaluating the efficacy and safety of INSTIs in treatment-naïve patients living with HIV as well as individuals at risk of acquiring HIV infection.

Adolescent retention in HIV care within differentiated service-delivery models in sub-Saharan Africa

Adolescents and young people living with HIV are at risk of disengaging from HIV care at all stages of the care cascade. Differentiated models of care offer simplified HIV-service delivery options in the hope of improving treatment outcomes, including retention on antiretroviral therapy. However, it remains unclear how successful and widespread these models are for adolescents in sub-Saharan Africa, where the burden of HIV is the greatest. Very few differentiated models of care specifically targeted to adolescents can be found and this priority group are currently ineligible from several models that exist. Where differentiated care has been made available to adolescents, data on the implementation and effectiveness of these interventions remain scarce. Despite this scarcity of evidence on the effectiveness of differentiated care among adolescent populations, several interventions, particularly community-based groups with peer navigators or supporters, might have potential to increase the reach, effectiveness, and adoption of differentiated care in adolescent HIV-care programmes.

Brief Report: Impact of COVID-19 on Cabotegravir Plus Rilpivirine Long-Acting Dosing Across 6 Ongoing Global Phase IIb and III Clinical Trials

BACKGROUND

Cabotegravir + rilpivirine long-acting (LA) is a novel antiretroviral therapy (ART) administered intramuscularly monthly or every 2 months by a health care provider. The COVID-19 pandemic presents a potential challenge to patients' ability to attend scheduled clinic visits for dosing administration.

SETTING

This analysis evaluated implementation fidelity across 6 phase IIb/III/IIIb cabotegravir + rilpivirine LA clinical trials in 16 countries during the COVID-19 pandemic.

METHODS

COVID-19-impacted visits were defined as modified dosing visits for which oral therapy was provided to participants unable to attend the clinic or injection visits that were rescheduled. Data from December 1, 2019, to March 1, 2021, were aggregated and analyzed using descriptive statistics.

RESULTS

Of 2127 participants in cabotegravir + rilpivirine LA trials, 1997 (94%) had LA dosing visits proceed as planned during the COVID-19 pandemic. Of 130 (6%) participants with injection visits affected by COVID-19, most were from North America (57%) and Europe (26%). Most participants with COVID-19-impacted visits used oral therapy with cabotegravir + rilpivirine (75%) or alternative oral standard-of-care ART (21%) to maintain continuous ART. The most common reasons for missed visits were clinic closure/staffing constraints (48%) and COVID-19-related travel restrictions (23%). Most (98%) participants who used oral ART maintained virologic suppression; 2 participants had viral load between 50 and 100 copies/mL.

CONCLUSION

During the COVID-19 pandemic, most trial participants maintained their LA dosing schedules. Flexibility of the LA dosing regimen, with the ability to switch to oral therapy, facilitated continuous ART provision and implementation fidelity.

Long-Acting Injectable Cabotegravir for HIV Prevention: What Do We Know and Need to Know about the Risks and Consequences of Cabotegravir Resistance?

PURPOSE OF REVIEW

Cabotegravir is a potent integrase strand transfer inhibitor (INSTI) recently approved as a long-acting injectable formulation for HIV prevention (CAB-LA). We summarize what is known about cabotegravir pharmacokinetics, activity, and emergence of resistance from in vitro, macaque and clinical studies, and we evaluate the risk of resistance from CAB-LA with on-time injections and after CAB-LA discontinuation.

RECENT FINDINGS

The accumulation of multiple INSTI mutations is required for high-level cabotegravir resistance, and the same mutation combinations may cause cross-resistance to dolutegravir, which is widely used for first-line antiretroviral therapy in low- and middle-income countries. Though CAB-LA was highly effective in preventing HIV, breakthrough infections did occur in trials of CAB-LA despite on-time injections, resulting in selection of single and combinations of INSTI resistance mutations. As CAB-LA is scaled-up, prompt HIV diagnosis to prevent resistance, and resistance monitoring could help preserve the effectiveness of INSTIs for both HIV treatment and prevention.

Frequency of genotypic factors possibly associated with cabotegravir/rilpivirine failure in antiretroviral treatment-naïve and -experienced HIV-1- infected population

OBJECTIVES

The long-acting injectable (LAI) cabotegravir (CAB) and rilpivirine (RPV) treatment offers important advantages over oral ART (antiretroviral therapy), however baseline factors possibly contributing to the CAB/RPV treatment failure were identified. The purpose of this study was to describe the frequency of virologic factors previously influencing efficacy of this treatment, namely RPV and CAB resistance-associated mutations (RAMs) and A1/A6 subtype among naïve and treatment-experienced HIV-1-infected patients from Poland.

METHODS

The following datasets of HIV-1 sequences were analysed: 4809 protease and reverse transcriptase (PR/RT) sequences obtained from 4649 Polish Caucasian patients (4122 naive and 687 non-naïve) supplemented with integrase (PR/RT/INT) sequences in 1217 cases (942 naïve and 275 non-naïve). Sub-subtypes A were assigned by phylogenetic methods. Major and minor CAB and RPV RAMs were determined according to the IAS-USA 2019 list, while minor RAMs were additionally defined based on the Stanford database algorithm.

RESULTS

Subtype A1/A6 frequency ranged from 6.11% in ART failing cases with PR/RT sequences only, to 15.92% for the PR/RT/INT treatment-naïve dataset, while RPV RAMs were found in up to 5.89% of treatment-naïve and 14.56% of ART failing cases. Regardless treatment history, only <1% sequences had combination of two factors (RPV RAMs and A1/A6 subtype). Furthermore, CAB RAMs were found in 1.27% of treatment-naïve and 14.54% of experienced patients.

CONCLUSIONS

Despite notable frequency of subtype A1/A6 or CAB/RPV RAMs analysed separately, combination of at least two factors previously associated with failure or this treatment is rare. As subtype A1/A6 becomes more common across real-life cohorts continued subtyping and RAM screening will remain of key importance for LAI treatment implementation. Sequence data from this article have been deposited in GenBank under accession numbers: GU906860, GU906864, GU906871-GU906874, JQ305750-JQ305791, KC409134-KC409222, KM057341-KM057362, KM283892-KM284490, KT340108-KT340205, MZ468643-MZ468894, MZ671788-MZ671823, OP298017-OP302727.

Background factors in people living with HIV in Japan who switch to cabotegravir plus rilpivirine: A pilot study

Long-acting therapy of cabotegravir and rilpivirine is expected to free people from the negative emotions of living with HIV associated with taking drugs, but problems such as increased number of hospital visits, lack of anti-HBV activity, and limited convenience in people with concomitant drugs have been noted. In this single-center, prospective, cross-sectional study, we investigated background factors of people living with HIV in Japan who chose cabotegravir plus rilpivirine. Forty-seven percent (36 of 76) of individuals chose this regimen, but many people living with HIV who visited the hospital once every 3 months or needed concomitant medications due to complications chose this regimen and there were no significant differences in background factors that could affect convenience between the groups of those who switched and those who did not.

Early Experience Implementing Long-acting Injectable Cabotegravir/Rilpivirine for HIV-1 Treatment at a Ryan White-funded Clinic in the U.S. South

Background

Long-acting injectable (LAI) antiretroviral therapy (ART) has the potential to improve medication adherence, reduce human immunodeficiency virus (HIV) stigma, and promote equity in care outcomes among people with HIV (PWH). We describe our early experience implementing LAI-cabotegravir/rilpivirine (CAB/RPV) for maintenance HIV-1 treatment.

Methods

We launched a pilot LAI-ART program at a large Ryan White-funded clinic in the Southeast, which accept provider-initiated referrals from April 14, 2021 to December 1, 2021. Our interdisciplinary program team (Clinician-Pharmacy-Nursing) verified clinical eligibility and pursued medication access for eligible patients. We describe (1) demographic and clinical variables of PWH referred and enrolled and (2) early outcomes among those accessing LAI-CAB/RPV.

Results

Among 58 referrals, characteristics were median age 39 (Q1–Q3, 30.25–50) years, 74% male, and 81% Black, and payor source distribution was 26% Private, 21% Medicare, 19% Medicaid, and 34% AIDS Drugs Assistance Program. Forty-five patients (78%) met clinical eligibility for LAI-CAB/RPV; ineligibility concerns included evidence of confirmed or possible RPV resistance (n = 8), HIV nonsuppression (n = 3), possible RPV hypersensitivity (n = 1), and pregnancy (n = 1). Among 45 eligible PWH, 39 (87%) enrolled and 15 (38%) initiated LAI-CAB/RPV after a median of 47 (Q1–Q3, 31–95) days since enrollment.

Conclusions

Implementing LAI-ART at a Southern US Ryan White-funded clinic has been challenged by the following: substantial human resource capital to attain drug, administer injections, and support enrolled patients; delayed therapy initiation due to insurance denials; patient ineligibility primarily due to possible RPV resistance; and inability to provide drug regardless of payor source. These barriers may perpetuate disparities in ART access and outcomes among PWH and should be urgently addressed so that LAI-ART can be offered equitably.

Perspectives of people living with HIV-1 on implementation of long-acting cabotegravir plus rilpivirine in US healthcare settings: results from the CUSTOMIZE hybrid III implementation-effectiveness study

INTRODUCTION

The CUSTOMIZE hybrid III implementation-effectiveness study evaluated implementation of once-monthly long-acting (LA) cabotegravir + rilpivirine in diverse US healthcare settings. Here, we report patient participant perspectives after 12 months in CUSTOMIZE.

METHODS

CUSTOMIZE was a phase IIIb, 12-month study conducted from July 2019 to October 2020 at eight diverse US HIV clinics that enrolled virologically suppressed people living with HIV-1 (PLHIV) on a stable oral regimen to receive monthly cabotegravir + rilpivirine LA injections after a 1-month oral lead-in. Participants were administered quantitative surveys before injections at months 1 (baseline), 4 and 12. A randomly selected subset of participants was interviewed at baseline and month 12. Data collection at month 12 was completed by October 2020 (during the COVID-19 pandemic).

RESULTS

At baseline, 109 and 34 participants completed surveys and interviews, respectively; 87% were male; 35% were Black or African American. All participants who remained in the study at month 12 (n = 102) maintained HIV-1 RNA <50 copies/ml; two participants withdrew due to injection-related reasons. Mean total scores measuring acceptability and appropriateness of cabotegravir + rilpivirine LA were high at baseline (4.5-4.6 out of 5) and month 12 (4.7-4.9). At month 12, 74% of participants reported nothing interfered with receiving LA injections; injection pain or soreness was the most common concern (15%). Time spent in the clinic and coming to the clinic for monthly injections was very or extremely acceptable after 12 months for most participants (93% and 87%, respectively), with 64% reporting having spent ≤30 minutes in the clinic for injection visits. At month 12, 92% of participants preferred LA injections to daily oral tablets (3%); 97% plan to continue LA treatment going forward. In month 12 interviews, 24 (77%) of 31 participants reported the COVID-19 pandemic did not impact their ability to receive treatment.

CONCLUSIONS

Once-monthly cabotegravir + rilpivirine LA was highly acceptable among PLHIV who were virologically suppressed on a stable antiretroviral regimen and interested in trying LA therapy, with few participants reporting challenges receiving LA injections. Implementation data from CUSTOMIZE suggest that monthly LA injections provide a convenient and appealing treatment option for PLHIV.

A year in pharmacology: new drugs approved by the US Food and Drug Administration in 2021

The second year of the COVID-19 pandemic had no adverse effect on the number of new drug approvals by the US Food and Drug Administration (FDA). Quite the contrary, with a total of 50 new drugs, 2021 belongs to the most successful FDA years. We assign these new drugs to one of three levels of innovation: (1) first drug against a condition ("first-in-indication"), (2) first drug using a novel molecular mechanism ("first-in-class"), and (3) "next-in-class", i.e., a drug using an already exploited molecular mechanism. We identify 21 first-in-class, 28 next-in-class, and only one first-in-indication drugs. By treatment area, the largest group is once again cancer drugs, many of which target specific genetic alterations. Every second drug approved in 2021 targets an orphan disease, half of them being cancers. Small molecules continue to dominate new drug approvals, followed by antibodies and non-antibody biopharmaceuticals. In 2021, the FDA continued to approve drugs without strong evidence of clinical effects, best exemplified by the aducanumab controversy.

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.

Synthetic Approaches to the New Drugs Approved During 2020

New drugs introduced to the market are privileged structures that have affinities for biological targets implicated in human diseases and conditions. These new chemical entities (NCEs), particularly small molecules and antibody-drug conjugates (ADCs), provide insight into molecular recognition and simultaneously function as leads for the design of future medicines. This Review is part of a continuing series presenting the most likely process-scale synthetic approaches to 44 new chemical entities approved for the first time anywhere in the world during 2020.

The future of long-acting cabotegravir plus rilpivirine therapy: Deeds and misconceptions

HIV infection is currently managed as a chronic disease thanks to the improvement of antiretroviral therapy (ART). In this light, treatment is lifelong. Therefore, switch to new regimens is a natural event during long-term therapies to avoid problems related to toxicity, adherence, failure and potential selection of drug resistance. In this context, coformulations of multiple agents in one pill and the development of novel drug classes and drugs with high genetic barrier to resistance are now available. The recent approval of the long-acting once monthly or bimonthly injectable combination of the second-generation strand transfer integrase inhibitor (InSTI) cabotegravir (CAB) together with the non-nucleoside reverse transcriptase inhibitor (NNRTI) rilpivirine (RPV) represents the most recent achievement along the line of potent and convenient ART. Several pivotal trials (such as LATTE-2, ATLAS, FLAIR, and ATLAS-2M) largely demonstrated the high efficacy and safety of this long-acting formulation used as an induction-maintenance strategy. Few confirmed virological failures (CVF) have been observed. The combination of at least two baseline factors among HIV-1 subtype A6/A1, a body mass index ≥30 kg/m², and RPV resistance associated mutations, was associated with an increased risk of CVF at week 48. Available data indicate that this long-acting therapeutic strategy is attractive and potent, thus defining the most appropriate patient and how to handle practical issues is warranted.