Evaluating cabotegravir/rilpivirine long-acting, injectable in the treatment of HIV infection: emerging data and therapeutic potential

Factors Associated with Preferences for Long-Acting Injectable Antiretroviral Therapy Among Adolescents and Young People Living with HIV in South Africa

Long-acting injectable anti-retroviral therapy (LAART) may overcome barriers to long-term adherence and improve the survival of adolescents and young people living with HIV (AYLHIV). Research on the acceptability of LAART for this age-group is limited. We asked 953 AYLHIV about their preferred (theoretical) ART mode of delivery (pill, injectable, or other) in 2017-2018, before LAART was available or known to AYLHIV in South Africa. One in eight (12%) AYLHIV preferred LAART over single or multiple pill regimens. In multivariate analyses, six factors were associated with LAART preference: medication stock-outs (aOR = 2.56, 95% CI 1.40-4.68, p = 0.002), experiencing side-effects (aOR = 1.84, 95% CI 1.15-2.97, p = 0.012), pill-burden (aOR = 1.88, 95% CI 1.20-2.94, p = 0.006), past-year treatment changes (aOR = 1.63, 95% CI 1.06-2.51, p = 0.025), any HIV stigma (aOR = 2.22, 95% CI 1.39-3.53, p ≤ 0.001) and recent ART initiation (aOR = 2.02, 95% CI 1.09-3.74, p = 0.025). In marginal effects modelling, 66% of adolescents who experienced all factors were likely to prefer LAART, highlighting the potential high acceptability of LAART among adolescents and young people living with HIV struggling to adhere and have good HIV treatment outcomes. Adolescent boys who reported high ART pill burden were more likely to prefer LAART than their female peers in moderation analyses, suggesting that LAART may be particularly important to improve treatment outcomes among male AYLHIV as they become older. Adding LAART to existing treatment options for AYLHIV, particularly higher risk groups, would support AYLHIV to attain and sustain viral suppression-the third 95, and reduce their risk of AIDS-related mortality.

A computational overview of integrase strand transfer inhibitors (INSTIs) against emerging and evolving drug-resistant HIV-1 integrase mutants

AIDS (Acquired immunodeficiency syndrome) is one of the chronic and potentially life-threatening epidemics across the world. Hitherto, the non-existence of definitive drugs that could completely cure the Human immunodeficiency virus (HIV) implies an urgent necessity for the discovery of novel anti-HIV agents. Since integration is the most crucial stage in retroviral replication, hindering it can inhibit overall viral transmission. The 5 FDA-approved integrase inhibitors were computationally investigated, especially owing to the rising multiple mutations against their susceptibility. This comparative study will open new possibilities to guide the rational design of novel lead compounds for antiretroviral therapies (ARTs), more specifically the structure-based design of novel Integrase strand transfer inhibitors (INSTIs) that may possess a better resistance profile than present drugs. Further, we have discussed potent anti-HIV natural compounds and their interactions as an alternative approach, recommending the urgent need to tap into the rich vein of indigenous knowledge for reverse pharmacology. Moreover, herein, we discuss existing evidence that might change in the near future.

Realizing the promise of long-acting antiretroviral treatment strategies for individuals with HIV and adherence challenges: an illustrative case series

BACKGROUND

Adherence to antiretroviral treatment (ART) remains the cornerstone of optimal HIV outcomes, including viral suppression (VS), immune recovery, and decreased transmission risk. For many people with HIV (PWH), particularly those with early-acquired HIV, structural, behavioral, and cognitive barriers to adherence and competing priorities related to life events may be difficult to overcome, resulting in nonadherence. Long-acting injectable antiretroviral therapies (LAI-ART) may be a useful strategy to overcome some of these barriers. However, to date, the approved LAI-ART strategies (e.g., cabotegravir and rilpivirine (CAB/RPV)) have targeted those who have already attained viral suppression, precluding their use in the 40% of adolescents and young adults (AYA) that VS has eluded.

CASE PRESENTATION

Ms. X is a 30-year-old woman with perinatally-acquired HIV and barriers to adherence. Despite many interventions, she remained persistently viremic, with resultant immune suppression and multiple comorbid opportunistic conditions, and viral load (VL) > 10,000,000 copies/ml. Given her longstanding history of poor adherence to an oral regimen, a switch to monthly intramuscular (IM) injections and biweekly infusions of ibalizumab were initiated leading to decreased viral load to 8,110 copies/ml within two weeks. Ms. H is a 33-year-old woman with cognitive limitations due to childhood lead poisoning. Her viral load trajectory took a downward turn, precipitated by various life events, remaining elevated despite intensive case management. Initiation of LAI-ART (CAB/RPV) in this patient led to an undetectable VL (< 20 copies/ml) within two months of treatment initiation. Miss Y. is a 37-year-old woman with perinatally-acquired HIV and chronic challenges with nonadherence and longstanding immunosuppression with CD4 < 200 cells/mm³ for > 5 years. She received a 1-month oral lead-in (OLI) of cabotegravir/rilpivirine, followed by the injectable loading dose. She has since adhered to all her monthly dosing appointments, sustained VS, and transitioned to a bi-monthly injection schedule.

CONCLUSION

These three individuals with HIV (perinatally and non-perinatally acquired) with longstanding nonadherence and persistent viremia were successfully initiated on LAI-ART through the process of care coordination and the collective efforts of the care team, highlighting the barriers, challenges, and the multidisciplinary coordination needed to assure successful implementation of this strategy for the most vulnerable of patients.

A Patient Decision Aid (i.ARTs) to Facilitate Women's Choice Between Oral and Long-Acting Injectable Antiretroviral Treatment for HIV: Protocols for its Development and Randomized Controlled Pilot Trial

BACKGROUND

Many women with HIV (WWH) have suboptimal adherence to oral antiretroviral therapy (ART) due to multilevel barriers to HIV care access and retention. A long-acting injectable (LAI) version of ART was approved by the US Food and Drug Administration in January 2021 and has the potential to overcome many of these barriers by eliminating the need for daily pill taking. However, it may not be optimal for all WWH. It is critical to develop tools that facilitate patient-provider shared decision making about oral versus LAI ART modalities to promote women's adherence and long-term HIV outcomes.

OBJECTIVE

This study will develop and pilot test a web-based patient decision aid called i.ART+support (i.ARTs). This decision aid aims to support shared decision making between WWH and their providers, and help women choose between oral and LAI HIV treatment.

METHODS

The study will occur in 3 phases. In phase 1, we will utilize a mixed methods approach to collect data from WWH and medical and social service providers to inform i.ARTs content. During phase 2, we will conduct focus groups with WWH and providers to refine i.ARTs content and develop the web-based decision aid. In phase 3, i.ARTs will be tested in a randomized controlled trial with 180 women in Miami, Florida, and assessed for feasibility, usability, and acceptability, as well as to evaluate the associations between receiving i.ARTs and viral suppression, ART pharmacy refills, and clinic attendance.

RESULTS

This study was funded in March 2021. Columbia University's IRB approved the study protocols (approval number IRB-AAAT5314). Protocols for phase 1 interviews have been developed and interviews with service providers started in September 2021. We will apply for Clinicaltrials.gov registration prior to phase 3, which is when our first participant will be enrolled in the randomized controlled trial. This is anticipated to occur in April 2023.

CONCLUSIONS

This study is the first to develop a web-based patient decision aid to support WWH choices between oral and LAI ART. Its strengths include the incorporation of both patient and provider perspectives, a mixed methods design, and implementation in a real-world clinical setting.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/35646.

Cabenuva: the last FDA-approved drug to treat HIV

INTRODUCTION

The conventional combination antiretroviral therapy (cART) besides all its benefits, exhibited poor adherence to daily pill administration, life-long treatment period and emergence of viral resistance. The development of long-acting (LA) drugs have changed the management of common medical conditions for human immunodeficiency virus (HIV). Cabenuva is the first LA antiretroviral injectable drug composed of nano-formulation of cabotegravir (CAB) and rilpivirine (RPV).

AREAS COVERED

In this review article, we aim to have a brief overview of results of major clinical trials which administrated cabenuva for patients considering the efficacy and safety profiles. Moreover, we discuss about CAB and RPV chemical structure, mechanism of action, ‎activity against drug-sensitive and resistant HIV and pharmacodynamics/ pharmacokinetics properties.

EXPERT OPINION

Based on the results of the ATLAS and FLAIR trials, cabenuva regimen once-monthly has shown equal effectivity to oral cART in maintaining HIV-1 suppression in patients. Furthermore, ATLAS-2M study revealed the non-inferiority of cabenuva regimen every 8 weeks compared to every 4 weeks. The injectable LA ART, reduces the number of treatment intake as well as increases adherence especially in patients with HIV-related stigma. Administration of extended-release agents probably minimize the risk of treatment-related toxicity and resistance related to sub-optimal adherence to oral ART, so cabenuva can be suggested as a suitable alternative for HIV infection control in current era.

Perspectives on preparing for long-acting injectable treatment for HIV among consumer, clinical and nonclinical stakeholders: A qualitative study exploring the anticipated challenges and opportunities for implementation in Los Angeles County

Long-acting injectable (LAI) antiretroviral therapy (ART) is a novel HIV treatment option for people with HIV. The first LAI ART regimen for HIV treatment received regulatory approval in the United States in January 2021. In February 2020, we collected qualitative data from 18 consumers and 23 clinical and non-clinical stakeholders to catalog anticipated individual-consumer, healthcare system, and structural levels barriers and facilitators to LAI ART implementation in Los Angeles County, California. Thematic analysis was guided by the CFIR implementation science model. CFIR constructs of intervention characteristics, individual characteristics, outer and inner setting, intervention characteristics, and implementation process emerged in analysis. Under intervention characteristics, anticipated facilitators included the relative advantage of LAI ART over pills for adherence and reduced treatment management burden and related anxiety; anticipated barriers included non-adherence to injection appointments, concerns of developing HIV resistance, discomfort with injection and cost. Anticipated facilitators based on individual characteristics included overall acceptability based on knowledge and positive beliefs about LAI ART. Participant noted several characteristics of the outer setting that could negatively impact implementation, such as medical mistrust, external policies, and LAI ART eligibility (i.e., to be virally suppressed prior to initiation). Participants were optimistic about the potential to decrease stigma but expressed that provider willingness for adoption could be hindered by challenges in organizational inner setting related to payment authorizations, increased staffing needs, medication procurement and storage, and provider and healthcare system readiness. Results from this pre-implementation study may inform rollout and scale-up of LAI ART in Los Angeles County.

Journey to the Market: The Evolution of Biodegradable Drug Delivery Systems

Biodegradable polymers have been used as carriers in drug delivery systems for more than four decades. Early work used crude natural materials for particle fabrication, whereas more recent work has utilized synthetic polymers. Applications include the macroscale, the microscale, and the nanoscale. Since pioneering work in the 1960’s, an array of products that use biodegradable polymers to encapsulate the desired drug payload have been approved for human use by international regulatory agencies. The commercial success of these products has led to further research in the field aimed at bringing forward new formulation types for improved delivery of various small molecule and biologic drugs. Here, we review recent advances in the development of these materials and we provide insight on their drug delivery application. We also address payload encapsulation and drug release mechanisms from biodegradable formulations and their application in approved therapeutic products.

Use of long-acting injectable antiretroviral agents for human immunodeficiency Virus: A review

The development of potent antiretroviral drugs has significantly reduced morbidity and mortality associated with human immunodeficiency virus infection, however, the effectiveness of these medications depends upon consistent daily oral intake. Non-adherence can lead to the emergence of resistance, treatment failure and disease progression. This has necessitated the development of long-acting antiretroviral formulations administrable via an infrequent dosing regimen. Long-acting injectable forms of cabotegravir and rilpivirine have reached various stages in clinical trials both for the treatment and prevention of HIV. Other long-acting agents are at various stages of development. This review evaluates the current research on the development of long-acting injectable antiretroviral agents for the treatment and prevention of HIV.

Novel Antiretroviral Therapeutic Strategies for HIV

When the first cases of HIV infection appeared in the 1980s, AIDS was a deadly disease without any therapeutic alternatives. Currently, there is still no cure for most cases mainly due to the multiple tissues that act as a reservoir for this virus besides the high viral mutagenesis that leads to an antiretroviral drug resistance. Throughout the years, multiple drugs with specific mechanisms of action on distinct targets have been approved. In this review, the most recent phase III clinical studies and other research therapies as advanced antiretroviral nanodelivery systems will be here discussed. Although the combined antiretroviral therapy is effective in reducing viral loading to undetectable levels, it also presents some disadvantages, such as usual side effects, high frequency of administration, and the possibility of drug resistance. Therefore, several new drugs, delivery systems, and vaccines have been tested in pre-clinical and clinical trials. Regarding drug delivery, an attempt to change the route of administration of some conventional antiretrovirals has proven to be successful and surpassed some issues related to patient compliance. Nanotechnology has brought a new approach to overcoming certain obstacles of formulation design including drug solubility and biodistribution. Overall, the encapsulation of antiretroviral drugs into nanosystems has shown improved drug release and pharmacokinetic profile.

An Overview of Human Immunodeficiency Virus-1 Antiretroviral Drugs: General Principles and Current Status

Treatment with highly active antiretroviral therapy (HAART) can prolong a patient's life-span by disrupting pivotal steps in the replication cycle of the human immunodeficiency virus-1 (HIV-1). However, drug resistance is emerging as a major problem worldwide due to the prolonged period of treatment undergone by HIV-1 patients. Since the approval of zidovudine in 1987, over thirty antiretroviral drugs have been categorized into the following six distinct classes based on their biological function and resistance profiles: (1) nucleoside analog reverse-transcriptase inhibitors; (2) non–nucleoside reverse transcriptase inhibitors; (3) integrase strand transferase inhibitors; (4) protease inhibitors; (5) fusion inhibitors; and (6) co-receptor antagonists. Additionally, several antiretroviral drugs have been developed recently, such as a long active drug, humanized antibody and pro-drug metabolized into an active form in the patient's body. Although plenty of antiretroviral drugs are beneficially used to treat patients with HIV-1, the ongoing efforts to develop antiretroviral drugs have overcome the drug resistances, adverse effects, and limited adherence of drugs observed in previous drugs to some extent. Furthermore, studies focused on agents targeting latent HIV-1 reservoirs should be strengthened, as that may lead to eradication of HIV-1.

Microarray patches: Breaking down the barriers to contraceptive care and HIV prevention for women across the globe

Despite the existence of a variety of contraceptive products for women, as well as decades of research into the prevention and treatment of human immunodeficiency virus (HIV), there is still a globally unmet need for easily accessible, acceptable, and affordable products to protect women's sexual and reproductive health. Microarray patches (MAPs) are a novel platform being developed for the delivery of hormonal contraception and antiretroviral drugs. MAPs provide enhanced drug delivery to the systemic circulation via the transdermal route when compared to transdermal patches, oral and injectable formulations. These minimally invasive patches can be self-administered by the user, reducing the burden on health care personnel. Since MAPs represent needle-free drug delivery, no sharps waste is generated after application, thereby eliminating possible MAP reuse and risk of needle-stick injuries. This review discusses the administration of contraceptive and antiretroviral drugs using MAPs, their acceptability by end-users, and the future perspective of the field.

Efficacy of silk fibroin biomaterial vehicle for in vivo mucosal delivery of Griffithsin and protection against HIV and SHIV infection ex vivo

Introduction

The majority of new HIV infections occur through mucosal transmission. The availability of readily applicable and accessible platforms for anti‐retroviral (ARV) delivery is critical for the prevention of HIV acquisition through sexual transmission in both women and men. There is a compelling need for developing new topical delivery systems that have advantages over the pills, gels and rings, which currently fail to guarantee protection against mucosal viral transmission in vulnerable populations due to lack of user compliance. The silk fibroin (SF) platform offers another option that may be better suited to individual circumstances and preferences to increase efficacy through user compliance. The objective of this study was to test safety and efficacy of SF for anti‐HIV drug delivery to mucosal sites and for viral prevention.

Methods

We formulated a potent HIV inhibitor Griffithsin (Grft) in a mucoadhesive silk fibroin (SF) drug delivery platform and tested the application in a non‐human primate model in vivo and a pre‐clinical human cervical and colorectal tissue explant model. Both vaginal and rectal compartments were assessed in rhesus macaques (Mucaca mulatta) that received SF (n = 4), no SF (n = 7) and SF‐Grft (n = 11). In this study, we evaluated the composition of local microbiota, inflammatory cytokine production, histopathological changes in the vaginal and rectal compartments and mucosal protection after ex vivo SHIV challenge.

Results

Effective Grft release and retention in mucosal tissues from the SF‐Grft platform resulted in protection against HIV in human cervical and colorectal tissue as well as against SHIV challenge in both rhesus macaque vaginal and rectal tissues. Mucoadhesion of SF‐Grft inserts did not cause any inflammatory responses or changes in local microbiota.

Conclusions

We demonstrated that in vivo delivery of SF‐Grft in rhesus macaques fully protects against SHIV challenge ex vivo after two hours of application and is safe to use in both the vaginal and rectal compartments. Our study provides support for the development of silk fibroin as a highly promising, user‐friendly HIV prevention modality to address the global disparity in HIV infection.

An open-label, randomized crossover study to evaluate the acceptability and preference for contraceptive options in female adolescents, 15 to 19 years of age in Cape Town, as a proxy for HIV prevention methods (UChoose)

Introduction

Young women in Southern Africa have extremely high HIV incidence rates necessitating the availability of female‐controlled prevention methods. Understanding adolescent preference for seeking contraception would improve our understanding of acceptability, feasibility and adherence to similar modes of delivery for HIV prevention.

Methods

UChoose was an open‐label randomized crossover study over 32 weeks which aimed to evaluate the acceptability and preference for contraceptive options in healthy, HIV‐uninfected, female adolescents aged 15 to 19 years, as a proxy for similar HIV prevention methods. Participants were assigned to a contraceptive method for a period of 16 weeks in the form of a bi‐monthly injectable contraceptive, monthly vaginal Nuvaring^® or daily combined oral contraceptive (COC) and then asked to state their preference. At 16 weeks, participants crossed over to another contraceptive method, to ensure that all participants tried the Nuvaring^® (least familiar modality) and additionally, either the injection or COC. Primary outcomes were contraceptive acceptability and preference. At the end of the 32 weeks they were also asked to imagine their preference for an HIV prevention modality. Secondary endpoints included changes in sexual behaviour, contraceptive adherence and preference for biomedical and behavioural HIV prevention methods.

Results

Of the 180 participants screened, 130 were enrolled and randomized to the Nuvaring^® (n = 45), injection (n = 45) or COC (n = 40). Significantly more Nuvaring^® users (24/116; 20.7%) requested to change to another contraceptive option compared to injection (1/73; 1.4% p = 0.0002) and COC users (4/49; 8% p = 0.074). Of those that remained on the Nuvaring^®, adherence was significantly higher than to COC (p < 0.0001). Significantly more injection users (77/80; 96.3%) thought this delivery mode was convenient to use compared to Nuvaring^® (74/89; 83.1%; p = 0.0409) or COC (38/50; 76.0%; p = 0.0034). Overall, the preferred contraceptive choice was injection, followed by the ring and lastly the pill.

Conclusions

Adherence to daily COC was difficult for adolescents in this cohort and the least favoured potential HIV prevention option. While some preferred vaginal ring use, these data suggest that long‐acting injectables would be the preferred prevention method for adolescent girls and young women. This study highlights the need for additional options for HIV prevention in youth.

Adolescents and young adults with early acquired HIV infection in the united states: unique challenges in treatment and secondary prevention

INTRODUCTION

Worldwide, children who acquired human immunodeficiency virus (HIV) at an early age, either perinatally or through blood transfusion, are reaching adolescence and adulthood due to successful antiretroviral treatment (ART). While many are thriving, a significant proportion face unprecedented multilevel challenges that can affect their long-term outcomes. Specifically, longstanding and poorly controlled HIV resulting from inadequate early regimens and nonadherence, along with the toxicities of some ART agents, can predispose them to sequelae including HIV-associated complications and other comorbidities.

AREAS COVERED

This paper reviews and summarizes the unique issues facing adolescents and young adults with early acquired HIV (AYA-EAHIV), including ART challenges, emerging comorbidities, and complications, including mental health comorbidities, secondary prevention, and transition from pediatric/adolescent to adult care.

EXPERT OPINION

AYA-EAHIV are a special population that have lived their entire lives with the physical and psychological toll of HIV mandating targeted and purposeful approaches to optimize their management and outcomes. Multifaceted inclusive and context-specific approaches focusing on heightened research, risk reduction interventions, and 'outside the box' thinking will be required to optimize treatment and reduce morbidity and mortality.

Cabotegravir-Rilpivirine: The First Complete Long-Acting Injectable Regimen for the Treatment of HIV-1 Infection

Objective:

To review the efficacy and safety of cabotegravir (CAB) with rilpivirine (RPV) in the treatment of HIV-1 infection.

Data Sources:

A literature search was performed using PubMed and Google Scholar (2010 to January 2021) with the search terms cabotegravir and rilpivirine. Other resources included abstracts presented at recent conferences and the manufacturer’s website and prescribing information.

Study Selection:

All English-language articles of studies assessing the efficacy and safety of CAB with RPV were included.

Data Synthesis:

The combination of CAB, a new integrase strand transfer inhibitor, and RPV, an established nonnucleoside reverse transcriptase inhibitor, is the first long-acting dual therapy approved for the treatment of HIV-1 infection in adults who have achieved viral suppression on a standard antiretroviral therapy (ART). This regimen demonstrated comparable maintenance of viral suppression evaluated up to 160 weeks, with low rates of virological failure. CAB and RPV are available as suspension given intramuscularly in 2 separate injections every 4 weeks. Common adverse effects include injection site reactions, pyrexia, fatigue, and headache. CAB and RPV are also available as tablets given orally for bridging therapy.

Relevance to Patient Care and Clinical Practice:

This long-acting dual therapy represents an attractive option with a high barrier to resistance for adults who have achieved viral suppression on standard ART and who prefer monthly injections over daily oral therapy.

Conclusions:

CAB-RPV is the first complete long-acting injectable that provides a convenient way to maintain viral suppression with no negative effects on renal and bone health and few drug interactions.

Cost-effectiveness of the long-acting regimen cabotegravir plus rilpivirine for the treatment of HIV-1 and its potential impact on adherence and viral transmission: A modelling study

Introduction

Combination antiretroviral therapy (cART) improves outcomes for people living with HIV (PLWH) but requires adherence to daily dosing. Suboptimal adherence results in reduced treatment effectiveness, increased costs, and greater risk of resistance and onwards transmission. Treatment with long-acting (LA), injection-based ART administered by healthcare professionals (directly observed therapy (DOT)) eliminates the need for adherence to daily dosing and may improve clinical outcomes. This study reports the cost-effectiveness of the cabotegravir plus rilpivirine LA regimen (CAB+RPV LA) and models the potential impact of LA DOT therapies.

Methods

Parameterisation was performed using pooled data from recent CAB+RPV LA Phase III trials. The analysis was conducted using a cohort-level hybrid decision-tree and state-transition model, with states defined by viral load and CD4 cell count. The efficacy of oral cART was adjusted to reflect adherence to daily regimens from published data. A Canadian health service perspective was adopted.

Results

CAB+RPV LA is predicted to be the dominant intervention when compared to oral cART, generating, per 1,000 patients treated, lifetime cost-savings of $1.5 million, QALY and life-year gains of 107 and 138 respectively with three new HIV cases averted.

Conclusions

Economic evaluations of LA DOTs need to account for the impact of adherence and HIV transmission. This study adds to the existing literature by incorporating transmission and using clinical data from the first LA DOT regimen. Providing PLWH and healthcare providers with novel modes of ART administration, enhancing individualisation of treatment, may facilitate the achievement of UNAIDS 95-95-95 objectives.

Fully synthetic injectable depots with high drug content and tunable pharmacokinetics for long-acting drug delivery

Clinical studies have validated that antiretroviral (ARV) drugs can serve as an HIV pre-exposure prophylactic (PrEP) strategy. Dosing adherence remains a crucial factor determining the final efficacy outcomes, and both long-acting implants and injectable depot systems are being developed to improve patient adherence. Here, we describe an injectable depot platform that exploits a new mechanism for both formation and controlled release. The depot is a polymeric prodrug synthesized from monomers that incorporate an ARV drug tenofovir alafenamide (TAF) with degradable linkers that can be designed to control release rates. The prodrug monomers are synthetically incorporated into homopolymer or block designs that exhibit high drug weight percent (wt%) and also are hydrophobized in these prodrug segments to drive depot formation upon injection. Drug release converts those monomers to more hydrophilic pendant groups via linker cleavage, and as this drug release proceeds, the polymer chains losing hydrophobicity are then disassociated from the depot and released over time to provide a depot dissolution mechanism. We show that long-acting TAF depots can be designed as block copolymers or as homopolymers. They can also be designed with different linkers, for example with faster or slower degrading p-hydroxybenzyloxycarbonyl (Benzyl) and ethyloxycarbonyl (Alkyl) linkers, respectively. Diblock designs of p(glycerol monomethacrylate)-b-p(Alkyl-TAF-methacrylate) and p(glycerol monomethacrylate)-b-p(Benzyl-TAF-methacrylate) were first characterized in a mouse subcutaneous injection model. The alkylcarbamate linker design (TAF 51 wt%) showed excellent sustained release profiles of the key metabolite tenofovir (TFV) in skin and plasma over a 50-day period. Next, the homopolymer design with a high TAF drug wt% of 73% was characterized in the same model. The homopolymer depots with p(Alkyl-TAFMA) exhibited sustained TFV and TAF release profiles in skin and blood over 60 days, and TFV-DP concentrations in peripheral blood mononuclear cells (PBMC) were found to be at least 10-fold higher than the clinically suggested minimally EC90 protective concentration of 24 fmol/10⁶ cells. These are the first reports of sustained parent TAF dosing observed in mouse and TFV-DP in mouse PBMC. IVIS imaging of rhodamine labeled homopolymer depots showed that degradation and release of the depot coincided with the sustained TAF release. Finally, these polymers showed excellent stability in accelerated stability studies over a six-month time period, and exceptional solubility of over 700 mg/mL in the DMSO formulation solvent. The homopolymer designs have a drug reservoir potential of well over a year at mg/day dosing and may not require cold chain storage for global health and developed world long-acting drug delivery applications.

"A dream come true": Perspectives on long-acting injectable antiretroviral therapy among female sex workers living with HIV from the Dominican Republic and Tanzania

BACKGROUND

Long-acting injectable antiretroviral therapy (LA ART) was found to be non-inferior to daily oral ART in Phase 3 clinical trials. LA ART may offer an important alternative for people living with HIV with challenges adhering to daily oral ART or preferences for non-pill-based regimens.

METHODS

Using a mixed methods approach integrating survey, in-depth interview and biological data from female sex workers (FSW) living with HIV in Tanzania (N = 208) and the Dominican Republic (DR) (N = 201), we assessed factors associated with the potential likelihood of LA ART use if it were available. We conducted multivariate logistic regression and thematic content analysis.

RESULTS

Likelihood of LA ART use was high with 84.92% of FSW from the DR and 92.27% of FSW from Tanzania reporting they would be "likely" or "very likely" to use LA ART if available (p = 0.02). In Tanzania better HIV-related patient-provider communication (AOR 4.58; 95% CI 1.90-11.05) and quality of HIV clinical care (AOR 3.68; 95% CI 1.05-12.86) were positively associated with the high likelihood of LA ART use. In the DR, easier clinic access was associated with a higher likelihood of LA ART use (AOR 3.04; 95% CI 1.41-6.56), as was greater monthly income from sex work (AOR 2.37; 95% CI 1.27-4.41). In both settings, years on ART was significantly associated with a strong likelihood of LA ART use (TZ: AOR 1.16 per year; 95% CI 1.00-1.34/DR: AOR 1.07 per year; 95% CI 1.00-1.14). Qualitative findings underscored enthusiasm for LA ART and reinforced its potential to address sex work-specific barriers to daily oral ART adherence including work-related schedules and substance use.

CONCLUSIONS

We found a high likelihood of LA ART use if available among FSW in two diverse settings and documented barriers to future uptake. Community-driven approaches which include tailored health education and improved patient-provider communication and quality of care, as well as strategies to facilitate appointment adherence are needed to optimize LA ART use among FSW.

Development and validation of a multiplex UHPLC-MS/MS assay with stable isotopic internal standards for the monitoring of the plasma concentrations of the antiretroviral drugs bictegravir, cabotegravir, doravirine, and rilpivirine in people living with HIV

The widespread use of highly active antiretroviral treatments has dramatically changed the prognosis of people living with HIV (PLWH). However, such treatments have to be taken lifelong raising issues regarding the maintenance of both therapeutic effectiveness and long-term tolerability. Recently approved or investigational antiretroviral drugs present considerable advantages, allowing once daily oral dosage along with activity against resistant variants (eg, bictegravir and doravirine) and also parenteral intramuscular administration that facilitates treatment adherence (eg, long-acting injectable formulations such as cabotegravir and rilpivirine). Still, there remains a risk of insufficient or exaggerated circulating exposure due to absorption issues, abnormal elimination, drug-drug interactions, and others. In this context, a multiplex ultra-high performance liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS/MS) bioassay has been developed for the monitoring of plasma levels of bictegravir, cabotegravir, doravirine, and rilpivirine in PLWH. A simple and convenient protein precipitation was performed followed by direct injection of the supernatant into the UHPLC-MS/MS system. The four analytes were eluted in less than 3 minutes using a reversed-phase chromatography method coupled with triple quadrupole mass spectrometry detection. This bioassay was fully validated following international guidelines and achieved good performances in terms of trueness (94.7%-107.5%), repeatability (2.6%-11%), and intermediate precision (3.0%-11.2%) over the clinically relevant concentration ranges (from 30 to 9000 ng/mL for bictegravir, cabotegravir, and doravirine and from 10 to 1800 ng/mL for rilpivirine). This sensitive, accurate, and rapid UHPLC-MS/MS assay is currently applied in our laboratory for routine therapeutic drug monitoring of the oral drugs bictegravir and doravirine and is also intended to be applied for the monitoring of cabotegravir/rilpivirine levels in plasma from PLWH receiving once monthly or every 2-month intramuscular injection of these long-acting antiretroviral drugs.

High prevalence of integrase mutation L74I in West African HIV-1 subtypes prior to integrase inhibitor treatment

OBJECTIVES

HIV-1 integrase inhibitors are recommended as first-line therapy by WHO, though efficacy and resistance data for non-B subtypes are limited. Two recent trials have identified the integrase L74I mutation to be associated with integrase inhibitor treatment failure in HIV-1 non-B subtypes. We sought to define the prevalence of integrase resistance mutations, including L74I, in West Africa.

METHODS

We studied a Nigerian cohort of recipients prior to and during receipt of second-line PI-based therapy, who were integrase inhibitor-naive. Illumina next-generation sequencing with target enrichment was used on stored plasma samples. Drug resistance was interpreted using the Stanford Resistance Database and the IAS-USA 2019 mutation lists.

RESULTS

Of 115 individuals, 59.1% harboured CRF02_AG HIV-1 and 40.9% harboured subtype G HIV-1. Four participants had major IAS-USA integrase resistance-associated mutations detected at low levels (2%-5% frequency). Two had Q148K minority variants and two had R263K (one of whom also had L74I). L74I was detected in plasma samples at over 2% frequency in 40% (46/115). Twelve (26.1%) had low-level minority variants of between 2% and 20% of the viral population sampled. The remaining 34 (73.9%) had L74I present at >20% frequency. L74I was more common among those with subtype G infection (55.3%, 26/47) than those with CRF02_AG infection (29.4%, 20/68) (P = 0.005).

CONCLUSIONS

HIV-1 subtypes circulating in West Africa appear to have very low prevalence of major integrase mutations, but significant prevalence of L74I. A combination of in vitro and clinical studies is warranted to understand the potential implications.

HIV-1 integrase resistance associated mutations and the use of dolutegravir in Sub-Saharan Africa: a systematic review and meta-analysis protocol

BACKGROUND

Sub-Saharan Africa carries the greatest burden of HIV-infection with increasing drug resistance burden, which requires improved patient management and monitoring. Current WHO recommendations suggest transitioning to dolutegravir-based (adults) or raltegravir-based-regimens (neonates) for initial antiretroviral therapy (ART) and as a suitable alternative in cases of multi-resistance in resource-limited settings. This review aims at synthesizing the current knowledge on dolutegravir use and integrase resistance-associated mutations found before the wide use of dolutegravir-based regimens.

METHODS

This systematic review will include randomized and non-randomized trials, cohort, and cross-sectional studies published on dolutegravir use or integrase resistance-associated mutations in Sub-Saharan Africa. Searches will be conducted (from 2007 onwards) in PubMed, Embase, Cochrane Central Register of Controlled Trials (CENTRAL), Latin American and Caribbean Health Sciences Literature (LILAC), Web of Science, African Journals Online, and Cumulative Index to Nursing and Allied Health Literature (CINAHL) databases. Hand searching of the reference lists of relevant reviews and trials will be conducted and we will also look for conference abstracts. We will include studies of adults and/or children exposed to integrase inhibitors-based therapies; especially dolutegravir or raltegravir (which is our intervention of interest as compared to other antiretroviral regimens). We will exclude studies of patients with specific co-morbidities such as tuberculosis or opportunistic infections. Primary outcomes will be "the rate of viral suppression" and "the level of drug resistance" on integrase inhibitor-based regimens among patients in Sub-Saharan Africa. Secondary outcomes will be "the effect of baseline viremia on viral suppression," "the effect of treatment duration on viral suppression," "the proportion of patients with immune recovery," "the rate of non-adherence," "rate of adverse events;" "drug resistance according to different integrase inhibitor-based regimens," and "drug resistance according to viral subtypes/recombinants." Two reviewers will independently screen titles and abstracts, assess the full texts for eligibility, and extract data. If data permits, random effects models will be used where appropriate. Subgroup and additional analyses will be conducted to explore the potential sources of heterogeneity (e.g., age, sex, baseline viremia, CD4 following treatment, treatment duration, and adherence level).

DISCUSSION

This review will help to strengthen evidence on the effectiveness of integrase strand transfer inhibitors by contributing to current knowledge on the use of dolutegravir and/or raltegravir (especially for neonates) in Sub-Saharan Africa. Results will therefore help in setting-up baseline data for an optimal management of people living with HIV as Sub-Saharan African countries are transitioning to dolutegravir-based regimens. Evidence will also support HIV/AIDS programs in identifying gaps and actions to be undertaken for improved long-term care and treatment of people living with HIV in Sub-Saharan Africa.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42019122424.

A literature review of the patent application publications on cabotegravir - an HIV integrase strand transfer inhibitor

Introduction: Studies presented in the patent applications demonstrate that a new integrase strand transfer inhibitor cabotegravir might be used as long-acting antiretroviral formulation or delivery system that reduces dosing frequency and may therefore increase adherence and thus pre-exposure prophylaxis (PrEP) and treatment efficacy against HIV. As announced in 2019, the developer ViiV Healthcare seeks US and EU approval of long-acting, injectable HIV treatment.Area covered: This review covers all the patent applications published until October 2019 with cabotegravir in the examples or claim section of the patent application document. The patent applications cover drug substance synthesis, solid-state forms, therapeutic applications, in vitro and in vivo efficacy as well as the potential formulations of cabotegravir alone or in combination with other anti-HIV agents.Expert opinion: The results from multiple clinical studies suggest that cabotegravir can be used as PrEP agent and treatment agent against HIV. Multiple studies use cabotegravir in combination with other anti-HIV agents such as rilpivirine. Cabotegravir in combination with rilpivirine is an interesting therapeutic, due to the possibility of formulating long-acting formulation with dosing interval of every 4 weeks or less, thus reducing daily pill burden and improving patient's compliance.

Drug-drug interactions when treating HIV-related metabolic disorders

Introduction: Drug-drug interactions (DDI) between antiretroviral drugs and drugs for the treatment of metabolic disturbances in people living with human immunodeficiency virus (HIV) (PLWH) have represented a problem of paramount importance in the recent times. The problem has been mainly driven by sharing common metabolizing pathways. This problem has classically been worsened by the frequent use of pharmacokinetic boosters to enhance protease inhibitors and some integrase inhibitors plasma levels. Areas covered: This article focuses on the interactions between antiretroviral drugs and those drugs used to treat metabolic disturbances which frequently appear in PLWH. These include dyslipidemia, diabetes mellitus, hyperuricemia, and finally, drugs for the treatment of overweight and clinical obesity. References from PubMed, Embase, or Web of Science, among others, were reviewed. Expert opinion: The advent of safer drugs, in terms of DDI, in the antiretroviral and the metabolic field,such as non-boosted antiretrovirals and drugs with divergent metabolizing paths. Besides, learning by the caregivers on how to decrease and manage DDI, together with the extensive use of online updated DDI databases, has undoubtedly minimized the problem. The foreseeable increase in the burden of HIV-associated comorbidities and their associated treatments anticipates further complexities in the management of DDI in PLWH.