Long-acting parenteral nanoformulated antiretroviral therapy: interest and attitudes of HIV-infected patients

Engagement in Care, Awareness, and Interest in Long-Acting Injectable Anti-Retroviral Therapy

Long Acting Injectable (LAI) therapy to treat HIV is an alternative to daily oral medications. The success of early roll-out of LAI to eligible patients requires a better understanding of patients' awareness and interest in this novel therapy. We administered an electronic survey to patients attending an urban HIV clinic in the US South. Eligible participants were 18 + years old with a most recent HIV-1 viral load < 200 copies/ml, without any evidence of genotypic resistance to LAI components or chronic hepatitis B. Survey recipients were asked about current treatment, engagement in care, and knowledge of LAI. Between January-April 2023, 480 patients were screened; 319 were eligible, and 155 (49%) completed the survey. The majority (119, 77%) were aware of, and 87 (56%) were interested in LAI. In regression analysis, only age was associated with interest in LAI (OR 0.95, 95% CI 0.92,0.99). Among proposed benefits of injectables, ease of travel without pills, lack of daily pill-taking, and fewer medication interactions were most appealing. Among proposed concerns with injectables, higher cost and insurance coverage of the new medicine were most worrisome. A large majority of people with HIV (PWH) are aware of the newest treatment available, and just over half of our sample expressed interest in LAI. Older age was associated with lower interest in LAI. LAI is appealing for its convenience, privacy, and avoidance of drug interactions, while the increased costs associated with LAI need to be addressed.

Acceptability of Long-Acting Injectable Antiretroviral Therapy Among People with HIV Receiving Care at Three Ryan White Funded Clinics in the United States

Understanding the acceptability of long-acting injectable antiretroviral therapy (LAI-ART) among people with HIV (PWH), especially priority populations, is essential for effective implementation. We conducted semi-structured interviews with patients in three Ryan White-funded HIV clinics in San Francisco, Chicago, and Atlanta. We employed maximal variation sampling across age, gender, race, ethnicity, and time living with HIV and oversampled for individuals with suboptimal clinical engagement. An 8-step hybrid deductive and inductive thematic analysis approach guided data analysis. Between August 2020 and July 2021, we conducted 72 interviews. Median age was 46 years; 28% were ciswomen, 7% transwomen, 44% Black/African-American and 35% Latinx, 43% endorsed a psychiatric diagnosis, 35% were experiencing homelessness/unstable housing, and 10% had recent substance use. Approximately 24% were sub-optimally engaged in care. We observed a spectrum of LAI-ART acceptability, ranging from enthusiasm to hesitancy to rejection. We also characterized four emergent orientations towards LAI-ART: innovator, pragmatist, deliberator, and skeptic. Overall, the majority of participants expressed favorable initial reactions towards LAI-ART. Most approached LAI-ART pragmatically, but acceptability was not static, often increasing over the course of the interview. Participants considered their HIV providers as essential for affirming personal relevance. HIV stigma, privacy concerns, and medical mistrust had varied impacts, sometimes facilitating and other times hindering personal relevance. These findings held across priority populations, specifically young adults, cis/trans women, racial/ethnic minorities, and individuals with suboptimal clinical engagement. Further research is needed to explore the transition from hypothetical acceptance to uptake and to confirm the actual benefits and drawbacks of this treatment.

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.

Integrating long-acting injectable treatment to improve medication adherence among persons living with HIV and opioid use disorder: study protocol

BACKGROUND

Oral antiretroviral therapy (ART) has been effective at reducing mortality rates of people with HIV. However, despite its effectiveness, people who use drugs face barriers to maintaining ART adherence. Receipt of opioid agonist treatment, in the context of HIV care, is associated with medication adherence and decreased HIV viral loads. Recent pharmacological advancements have led to the development of novel long-acting, injectable, medications for both HIV (cabotegravir co-administered with rilpivirine) and OUD (extended-release buprenorphine). These therapies have the potential to dramatically improve adherence by eliminating the need for daily pill-taking. Despite the extensive evidence base supporting long-acting injectable medications for both HIV and OUD, and clinical guidelines supporting integrated care provision, currently little is known about how these medications may be optimally delivered to this population. This paper presents the study design for the development of a clinical protocol to guide the delivery of combined treatment for HIV and OUD using long-acting injectable medications.

METHODS

The study aims are to: (1) develop a clinical protocol to guide the delivery of combined LAI for HIV and OUD by conducting in-depth interviews with prospective patients, clinical content experts, and other key stakeholders; and (2) conduct This single group, open pilot trial protocol to assess feasibility, acceptability, and safety among patients diagnosed with HIV and OUD. Throughout all phases of the study, information on patient-, provider-, and organizational-level variables will be collected to inform future implementation.

DISCUSSION

Findings from this study will inform the development of a future study to conduct a fully-powered Hybrid Type 1 Effectiveness-Implementation design.

Preclinical Evaluation of Long-Acting Emtricitabine Semi-Solid Prodrug Nanoparticle Formulations

Long-acting injectable (LAI) formulations promise to deliver patient benefits by overcoming issues associated with non-adherence. A preclinical assessment of semi-solid prodrug nanoparticle (SSPN) LAI formulations of emtricitabine (FTC) is reported here. Pharmacokinetics over 28 days were assessed in Wistar rats, New Zealand white rabbits, and Balb/C mice following intramuscular injection. Two lead formulations were assessed for the prevention of an HIV infection in NSG-cmah^-/- humanised mice to ensure antiviral activities were as anticipated according to the pharmacokinetics. Cmax was reached by 12, 48, and 24 h in rats, rabbits, and mice, respectively. Plasma concentrations were below the limit of detection (2 ng/mL) by 21 days in rats and rabbits, and 28 days in mice. Mice treated with SSPN formulations demonstrated undetectable viral loads (700 copies/mL detection limit), and HIV RNA remained undetectable 28 days post-infection in plasma, spleen, lung, and liver. The in vivo data presented here demonstrate that the combined prodrug/SSPN approach can provide a dramatically extended pharmacokinetic half-life across multiple preclinical species. Species differences in renal clearance of FTC mean that longer exposures are likely to be achievable in humans than in preclinical models.

Novel Perspectives on the Design and Development of a Long-Acting Subcutaneous Raltegravir Injection for Treatment of HIV-In Vitro and In Vivo Evaluation

Antiretrovirals (ARVs) are a highly effective therapy for treatment and prevention of HIV infection, when administered as prescribed. However, adherence to lifelong ARV regimens poses a considerable challenge and places HIV patients at risk. Long-acting ARV injections may improve patient adherence as well as maintaining long-term continuous drug exposure, resulting in improved pharmacodynamics. In the present work, we explored the aminoalkoxycarbonyloxymethyl (amino-AOCOM) ether prodrug concept as a potential approach to long-acting ARV injections. As a proof of concept, we synthesised model compounds containing the 4-carboxy-2-methyl Tokyo Green (CTG) fluorophore and assessed their stability under pH and temperature conditions that mimic those found in the subcutaneous (SC) tissue. Among them, probe 21 displayed very slow fluorophore release under SC-like conditions (98% of the fluorophore released over 15 d). Compound 25, a prodrug of the ARV agent raltegravir (RAL), was subsequently prepared and evaluated using the same conditions. This compound showed an excellent in vitro release profile, with a half-life (t_½) of 19.3 d and 82% of RAL released over 45 d. In mice, 25 extended the half-life of unmodified RAL by 4.2-fold (t_½ = 3.18 h), providing initial proof of concept of the ability of amino-AOCOM prodrugs to extend drug lifetimes in vivo. Although this effect was not as pronounced as seen in vitro-presumably due to enzymatic degradation and rapid clearance of the prodrug in vivo-the present results nevertheless pave the way for development of more metabolically stable prodrugs, to facilitate long-acting delivery of ARVs.

Overcoming barriers to patient adherence: the case for developing innovative drug delivery systems

Poor medication adherence is a pervasive issue with considerable health and socioeconomic consequences. Although the underlying reasons are generally understood, traditional intervention strategies rooted in patient-centric education and empowerment have proved to be prohibitively complex and/or ineffective. Formulating a pharmaceutical in a drug delivery system (DDS) is a promising alternative that can directly mitigate many common impediments to adherence, including frequent dosing, adverse effects and a delayed onset of action. Existing DDSs have already positively influenced patient acceptability and improved rates of adherence across various disease and intervention types. The next generation of systems have the potential to instate an even more radical paradigm shift by, for example, permitting oral delivery of biomacromolecules, allowing for autonomous dose regulation and enabling several doses to be mimicked with a single administration. Their success, however, is contingent on their ability to address the problems that have made DDSs unsuccessful in the past.

Antiviral supramolecular polymeric hydrogels by self-assembly of tenofovir-bearing peptide amphiphiles

The development of long-acting antiviral therapeutic delivery systems is crucial to improve the current treatment and prevention of HIV and chronic HBV. We report here on the conjugation of tenofovir (TFV), an FDA approved nucleotide reverse transcriptase inhibitor (NRTI), to rationally designed peptide amphiphiles (PAs), to construct antiviral prodrug hydrogelators (TFV-PAs). The resultant conjugates can self-assemble into one-dimensional nanostructures in aqueous environments and consequently undergo rapid gelation upon injection into 1× PBS solution to create a drug depot. The TFV-PA designs containing two or three valines could attain instantaneous gelation, with one displaying sustained release for more than 28 days in vitro. Our studies suggest that minor changes in peptide design can result in differences in supramolecular morphology and structural stability, which impacted in vitro gelation and release. We envision the use of this system as an important delivery platform for the sustained, linear release of TFV at rates that can be precisely tuned to attain therapeutically relevant TFV plasma concentrations.

Acceptance Rate and Reasons for Rejection of Long Acting Injectable Antiretrovirals

In January 2021, cabotegravir/rilpivirine, the first extended-release injectable regimen for the treatment of Human Immunodeficiency Virus (HIV) was approved. Long-acting injections have the potential to improve adherence and viral suppression. We analyzed the acceptance rate of, and reasons for declining to switch to, the new regimen. During routine appointments, 102 people living with HIV (PLWH) were presented with information on the new medication and asked if they would like to switch from their current regimen. If they declined to switch, they were asked why. Sixty-nine percent of respondents declined to switch, with frequency of injections as the primary reason. Patients indicated they would be willing to switch if the interval between injections was longer. Forty percent of the patients accepting the injectable anti-retrovirals (ARVs) were not on any other medications. Barriers to switching to long-acting injectable ARVs include the need for more frequent provider visits, aversion to needles, and a perceived lack of evidence supporting the new medication.

Antiretroviral therapy experience, satisfaction, and preferences among a diverse sample of young adults living with HIV

Youth and young adults living with HIV (YLWH) have a high HIV infection rate and suboptimal oral medication adherence. Biomedical researchers hope that long-acting antiretroviral therapy (LAART) modalities can help those who struggle with daily oral adherence. While adults living with HIV have expressed interest in LAART, little research has explored perspectives of YLWH. This study explores ART experiences and perspectives on LAART through qualitative interviews with twenty diverse YLWH (18-29) in the United States. Data were analyzed using framework analysis. Most participants were satisfied with their current ART yet had experienced side effects or had struggled with daily adherence. Preferences for improving daily oral ART included making pills smaller and reformulating ART into flavored chewable gummies. Most expressed enthusiasm for LAART, although needle aversion and previous injection drug use were potential barriers for some. Approximately half were interested in an ART patch, though its visibility and fear of stigmatization was concerning. Few expressed interest in implantable ART, calling it unappealing. Although younger people are most likely to benefit from these advancements in HIV treatment, additional research is needed to identify gaps in uptake and to further explore perspectives of YLWH to improve the success of new treatment modalities.

Leveraging the therapeutic, biological, and self-assembling potential of peptides for the treatment of viral infections

Peptides and peptide-based materials have an increasing role in the treatment of viral infections through their use as active pharmaceutical ingredients, targeting moieties, excipients, carriers, or structural components in drug delivery systems. The discovery of peptide-based therapeutic compounds, coupled with the development of new stabilization and formulation strategies, has led to a resurgence of antiviral peptide therapeutics over the past two decades. The ability of peptides to bind cell receptors and to facilitate membrane penetration and subsequent intracellular trafficking enables their use in various antiviral systems for improved targeting efficiency and treatment efficacy. Importantly, the self-assembly of peptides into well-defined nanostructures provides a vast library of discrete constructs and supramolecular biomaterials for systemic and local delivery of antiviral agents. We review here the recent progress in exploiting the therapeutic, biological, and self-assembling potential of peptides, peptide conjugates, and their supramolecular assemblies in treating human viral infections, with an emphasis on the treatment strategies for Human Immunodeficiency Virus (HIV).

Are Patients and Their Providers Talking About Long-Acting Injectable Antiretroviral Therapy? Penetration into Clinical Encounters at Three U.S. Care Sites

Use of long-acting injectable antiretroviral therapy depends on patient awareness, provider discussion, and patient willingness to use. We conducted a postvisit survey with patients at 3 HIV clinics in San Francisco, Chicago, and Atlanta in May 2021 to assess for inequities in these early implementation phases.

Indirect comparison of 48-week efficacy and safety of long-acting cabotegravir and rilpivirine maintenance every 8 weeks with daily oral standard of care antiretroviral therapy in participants with virologically suppressed HIV-1-infection

Background

Efficacy and safety of long-acting cabotegravir (CAB) + rilpivirine (RPV) every 8 weeks (Q8W) versus daily oral standard of care (SoC) maintenance in treatment-experienced individuals with virologically suppressed human immunodeficiency virus type 1 (HIV-1) has not been directly compared in randomized clinical trials. This analysis aimed to indirectly compare these regimens.

Methods

An adjusted indirect treatment comparison of CAB + RPV Q8W with daily oral SoC was performed, using Phase 3 data from studies of CAB + RPV every 4 weeks (Q4W) vs SoC (ATLAS/FLAIR, n = 591 per group) and a Phase 3b trial of CAB + RPV Q8W vs Q4W (ATLAS-2M [excluding participants with prior CAB + RPV exposure]; n = 327 per group). Eligible participants were virologically suppressed (viral load < 50 HIV-1 ribonucleic acid (RNA) copies/mL), treatment-experienced individuals with HIV-1-infection. Treatment efficacy and safety assessments at Week 48 included virologic suppression and lack of virologic suppression (proportion of participants with plasma HIV-1 RNA < 50 copies/mL or ≥ 50 copies/mL, respectively; both as per FDA snapshot algorithm), CD4-cell count change from baseline, no virologic data, discontinuations due to adverse events (AEs), and overall AEs, serious AEs and Grade 3–5 AEs excluding injection-site reactions. A subgroup analysis stratified by baseline third active drug class was performed.

Results

Baseline characteristics between the Q4W arms of ATLAS/FLAIR and ATLAS-2M showed no significant differences or differences were not judged to be clinically relevant, apart from participants switching from a baseline third active drug class; more participants switched from integrase strand inhibitors in ATLAS/FLAIR, and from non-nucleoside reverse transcriptase inhibitors in ATLAS-2M. Injections of CAB + RPV Q8W showed no significant differences across efficacy and safety outcomes versus daily oral SoC. Univariate subgroup analysis found there were no significant differences on virologic suppression or lack of virologic suppression for any baseline third active drug class subgroup. These results suggest that CAB + RPV Q8W is non-inferior to daily oral SoC.

Conclusions

This analysis supports the therapeutic potential of CAB + RPV Q8W for virologically suppressed people living with HIV-1 infection seeking an alternative maintenance treatment option to daily oral SoC.

Trial registration: NCT02938520, NCT02951052, NCT03299049.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-022-07243-3.

Use of Long-Acting Therapies for HIV Care in Italy: Are People Living with HIV Prepared for Change? A Cross-Sectional Study

Two hundred two people living with HIV (PLWH) selected from outpatients at the Infectious Disease Institute, Fondazione Policlinico Universitario A. Gemelli IRCCS, in Rome (Italy) were consecutively enrolled from May to July 2021. We used an anonymous telephone questionnaire to investigate opinions of PLWH about combined antiretroviral (ARV) therapy and long-acting (LA) formulations of ARVs. All invited participants completed the questionnaire (100%). We found that most PLWH evaluated taking HIV pills for the rest of their life as a continuous, but undemanding commitment (61.4%; n = 124), although they were willing to stop the daily intake of HIV drugs (78.2%, n = 158). Moreover, most PLWH were unaware of the existence of LA therapies at the time of the investigation (60.4%, n = 122). Almost half the PLWH evaluated the need for injections in the hospital as an obstacle (51.4%, n = 104). Regarding the preference between monthly injections and taking pills everyday, most PLWH (68.8%, n = 139) stated that the injection was more advantageous than pills even if they had some pain/swelling at the injection site. The concern about LA therapy indicated most by PLWH was the possible lower efficacy of the drug (83.7%, n = 169). Regarding the possible benefits of LA therapy, those reported most by PLWH were feeling freer because they did not have to remember to take pills everyday (68,8%, n = 139). In conclusion, to date, PLWH in our cohort seem willing to accept LA therapy, but still show some concern about the efficacy of the new therapy and the obligation to come to the hospital to receive it. Thus, clinicians must take into account the needs of their patients and help them overcome their concerns to facilitate the transition to this new therapeutic modality. Clinical Trial Registration Number ID: 2424.

Long-acting cabotegravir and rilpivirine for HIV-1 suppression: switch to 2-monthly dosing after 5 years of daily oral therapy

OBJECTIVES

Long-acting formulations of cabotegravir (CAB) and rilpivirine (RPV) have demonstrated efficacy in Phase 3 studies. POLAR (NCT03639311) assessed antiviral activity and safety of CAB+RPV long-acting administered every 2 months (Q2M) in adults living with HIV-1 who previously received daily oral CAB+RPV in LATTE (NCT01641809).

DESIGN

A Phase 2b, multicenter, open-label, rollover study.

METHODS

LATTE participants with plasma HIV-1 RNA less than 50 copies/ml who completed at least 300 weeks on study were eligible. Participants elected to switch to either CAB+RPV long-acting Q2M or daily oral dolutegravir/RPV for maintenance of virologic suppression. The primary endpoint was the proportion of participants with HIV-1 RNA greater than or equal to 50 copies/ml at Month 12 (M12) per the Food and Drug Administration Snapshot algorithm. The incidence of confirmed virologic failure (CVF, two consecutive HIV-1 RNA measurements greater than or equal to 200 copies/ml), as well as safety, laboratory, and patient-reported outcomes (HIV Treatment Satisfaction and preference questionnaires) were also assessed.

RESULTS

Of 97 participants enrolled, 90 chose to receive CAB+RPV long-acting and seven chose dolutegravir/RPV. At M12, no participant had HIV-1 RNA greater than or equal to 50 copies/ml or met the CVF criterion in either treatment group. No new safety signals were identified. Total treatment satisfaction was high at Baseline and remained stable through M12 across both treatment groups. Overall, 88% (n = 77/88) of long-acting arm participants preferred CAB+RPV long-acting to oral CAB+RPV.

CONCLUSION

CAB+RPV long-acting maintained virologic suppression in participants who had previously received daily oral CAB+RPV for at least 5 years in LATTE, with a favorable safety profile. Most participants preferred CAB+RPV long-acting to their prior oral CAB+RPV regimen at M12.

Week 96 extension results of a Phase 3 study evaluating long-acting cabotegravir with rilpivirine for HIV-1 treatment

BACKGROUND

ATLAS (NCT02951052), a phase 3, multicenter, open-label study, demonstrated that switching to injectable cabotegravir (CAB) with rilpivirine (RPV) long-acting dosed every 4 weeks was noninferior at week (W) 48 to continuing three-drug daily oral current antiretroviral therapy (CAR). Results from the W 96 analysis are presented.

METHODS AND DESIGN

Participants completing W 52 of ATLAS were given the option to withdraw, transition to ATLAS-2M (NCT03299049), or enter an Extension Phase to continue long-acting therapy (Long-acting arm) or switch from CAR to long-acting therapy (Switch arm). Endpoints assessed at W 96 included proportion of participants with plasma HIV-1 RNA less than 50 copies/ml, incidence of confirmed virologic failure (CVF; two consecutive HIV-1 RNA ≥200 copies/ml), safety and tolerability, pharmacokinetics, and patient-reported outcomes.

RESULTS

Most participants completing the Maintenance Phase transitioned to ATLAS-2M (88%, n = 502/572). Overall, 52 participants were included in the W 96 analysis of ATLAS; of these, 100% (n = 23/23) and 97% (n = 28/29) in the Long-acting and Switch arms had plasma HIV-1 RNA less than 50 copies/ml at W 96, respectively. One participant had plasma HIV-1 RNA 50 copies/ml or higher in the Switch arm (173 copies/ml). No participants met the CVF criterion during the Extension Phase. No new safety signals were identified. All Switch arm participants surveyed preferred long-acting therapy to their previous daily oral regimen (100%, n = 27/27).

CONCLUSION

In this subgroup of ATLAS, 98% (n = 51/52) of participants at the Extension Phase W 96 analysis maintained virologic suppression with long-acting therapy. Safety, efficacy, and participant preference results support the therapeutic potential of long-acting CAB+RPV treatment for virologically suppressed people living with HIV-1.

Impact of long-acting therapies on the global HIV epidemic

Long-acting antiretroviral drugs have emerged as exciting treatment and preexposure prophylaxis (PrEP) options for people with HIV and at risk of HIV. Long-acting regimens may improve dosing convenience, tolerability and cost compared with current daily-based oral therapy. They can also circumvent stigma associated with oral therapy for both treatment and PrEP, thereby improving adherence and outcomes. Yet, multiple challenges remain, many specific to low-income and middle-income countries (LMICs), where the epidemic is most concentrated and HIV prevention and treatment options are limited. To optimize the use of long-acting formulations, key outstanding questions must be addressed. Uncertain costing, scale-up manufacturing, complex delivery systems and implementation challenges are potential barriers when considering the scalability of long-acting ARVs for global use.

Long-Acting Injectable Antiretroviral Agents for HIV Treatment and Prevention

Current oral antiretroviral agents provide highly effective treatment for patients infected with human immunodeficiency virus (HIV), and can be used as pre-exposure prophylaxis (PrEP) to prevent new HIV infections. Several single-tablet regimens with excellent antiviral efficacy have dramatically improved the quality of life of patients who can adhere to daily oral therapy. However, there is increasing demand on long-acting injectable antiretroviral agents for patients who cannot take oral agents or feel fatigue related to daily pill burden. Monthly long-acting (LA) cabotegravir (CAB) combined with rilpivirine (RPV) has recently been listed as optimizing agent for maintenance of HIV suppression in treatment-experienced patients whose viral load is undetectable for 3 to 6 months. Novel agents with different mechanism of action and long half-life extending dosing interval are being tested in phase 2 and 3 clinical trials. This review summarizes the data of efficacies and safety profiles of LA CAB with RPV regimen, and also new long-acting injectable antiretroviral agents in pipeline.

Preferences of Persons with or at Risk for Hepatitis C for Long-Acting Treatments

BACKGROUND

Whereas safe, curative treatments for hepatitis C virus (HCV) have been available since 2015, there are still 58 million infected persons worldwide, and global elimination may require new paradigms. We sought to understand the acceptability of long-acting HCV treatment approaches.

METHODS

A cross-sectional, 43-question survey was administered to 1457 individuals with HCV or at risk of HCV at 28 sites in 9 countries to assess comparative interest in a variety of long-acting strategies in comparison to oral pills.

RESULTS

Among HCV-positive participants, 37.7% most preferred an injection, 5.6% an implant, and 6% a gastric residence device, as compared to 50.8% who stated they would most prefer taking 1 to 3 pills per day. When compared directly to taking pills, differences were observed in the relative preference for an injection based on age (p<0.001), location (p<0.001), and prior receipt of HCV treatment (p=0.005), but not sex. When an implant was compared to pills, greater preference was represented by women (p=0.01) and adults of younger ages (p=0.012 per 5 years). Among participants without HCV, 49.5% felt that injections are stronger than pills, and 34.7% preferred taking injections to pills. Among those at-risk participants who had received injectable medications in the past, 123 out of 137 (89.8%) expressed willingness to receive one in the future.

CONCLUSIONS

These data point to high acceptability of long-acting treatments, which for a substantial minority, might even be preferred to pills for the treatment of HCV infection. Long-acting treatments for HCV infection might contribute to global efforts to eliminate hepatitis C.

Long-acting injectable HIV therapies: the next frontier

PURPOSE OF REVIEW

There has been significant development of long-acting injectable therapy for the management of HIV in recent years that has the potential to revolutionise HIV care as we know it. This review summarises the data and outlines the potential challenges in the field of long-acting antiretroviral therapy (ART).

RECENT FINDINGS

In recent years, monthly and two monthly long-acting injectable ART in the form of cabotegravir and rilpivirine has shown safety and efficacy in large-scale phase 3 randomised control trials. Also, agents with novel mechanisms of action, such as Lenacapavir, have been tested in early-phase studies and are currently being tested in phase 2-3 clinical trials; if successful, this may allow six-monthly dosing schedules.

SUMMARY

However, despite evidence that suggests that these therapies are efficacious and acceptable to patients, the challenge of integrating these agents into our current healthcare infrastructure and making these novel agents cost-effective and available to the populations most likely to benefit remains. The next frontier for long-acting therapy will be to introduce these agents in a real-world setting ensuring that the groups most in need of long-acting therapy are not left behind.

"Lighten This Burden of Ours": Acceptability and Preferences Regarding Injectable Antiretroviral Treatment Among Adults and Youth Living With HIV in Coastal Kenya

Background:

Long-acting injectable (LAI) antiretroviral therapy (ART) may offer persons living with HIV (PLWH) an attractive alternative to pill-based treatment options, yet acceptability data remain scant, especially in sub-Saharan Africa.

Methods:

We conducted 6 focus group discussions with PLWH, including key stake holder groups, and analyzed data with content analysis.

Results:

Initial reactions to the idea of LAI-ART were often positive. The primary advantages voiced were potential to facilitate improved adherence and alleviate the burden of daily pill-taking while avoiding inadvertent disclosure and HIV stigma. Potential side effects were a particular concern of the women. Most participants preferred clinic-based administration over self-injections at home due to concerns about safety, privacy, and potential need for refrigeration.

Conclusions:

LAI-ART may be acceptable in Kenya, provided injections are infrequent and delivered in a clinic setting. However, HIV stigma, fear of potential side effects, and limited clinical capacity would need to be addressed.

Nonstructured Treatment Interruptions Are Associated With Higher Human Immunodeficiency Virus Reservoir Size Measured by Intact Proviral DNA Assay in People Who Inject Drugs

The latent reservoir for human immunodeficiency virus type 1 (HIV-1) in CD4+ T cells is a major barrier to cure. HIV-1-infected persons who inject drugs (PWID) often struggle to maintain suppression of viremia and experience nonstructured treatment interruptions (NTIs). The effects of injecting drugs or NTIs on the reservoir are unclear. Using the intact proviral DNA assay, we found no apparent effect of heroin or cocaine use on reservoir size. However, we found significantly larger reservoirs in those with frequent NTIs or a shorter interval from last detectable HIV RNA measurement. These results have important implications for inclusion of PWID in HIV-1 cure studies.

Patient-Reported Outcomes Through 1 Year of an HIV-1 Clinical Trial Evaluating Long-Acting Cabotegravir and Rilpivirine Administered Every 4 or 8 Weeks (ATLAS-2M)

BACKGROUND

Advances in HIV-1 therapeutics have led to the development of a range of daily oral treatment regimens, which share similar high efficacy rates. Consequently, more emphasis is being placed upon the individual's experience of treatment and impact on quality of life. The first long-acting injectable antiretroviral therapy for HIV-1 (long-acting cabotegravir + rilpivirine [CAB + RPV LA]) may address challenges associated with oral treatment for HIV-1, such as stigma, pill burden/fatigue, drug-food interactions, and adherence. Patient-reported outcomes (PROs) collected in an HIV-1 clinical trial (ATLAS-2M; NCT03299049) comparing participants' experience with two dosing regimens (every 4 weeks [Q4W] vs. every 8 weeks [Q8W]) of CAB + RPV LA are presented herein.

METHODS

PRO endpoints evaluated through 48 weeks of therapy included treatment satisfaction (HIV Treatment Satisfaction Questionnaire [HIVTSQ]), treatment acceptance ("General Acceptance" domain of the Chronic Treatment Acceptance [ACCEPT^®] questionnaire), acceptability of injections (Perception of Injection [PIN] questionnaire), treatment preference (questionnaire), and reasons for switching to/continuing long-acting therapy (exploratory endpoint; questionnaire). Participants were randomized 1:1 to receive CAB + RPV LA Q8W or Q4W. Results were stratified by prior CAB + RPV exposure in either preplanned or post hoc analyses.

RESULTS

Overall, 1045 participants were randomized to the Q8W (n = 522) and Q4W (n = 523) regimens; 37% (n = 391/1045) had previously received CAB + RPV in ATLAS. For participants without prior CAB + RPV exposure, large increases from baseline were reported in treatment satisfaction in both long-acting arms (HIVTSQ status version), with Q8W dosing statistically significantly favored at Weeks 24 (p = 0.036) and 48 (p = 0.004). Additionally, improvements from baseline were also observed in the "General Acceptance" domain of the ACCEPT questionnaire in both long-acting arms for participants without prior CAB + RPV exposure; however, no statistically significant difference was observed between arms at either timepoint (Week 24, p = 0.379; Week 48, p = 0.525). Significant improvements (p < 0.001) in the "Acceptance of Injection Site Reactions" domain of the PIN questionnaire were observed from Week 8 to Weeks 24 and 48 in both arms for participants without prior CAB + RPV exposure. Participants with prior CAB + RPV exposure reported high treatment satisfaction (mean [HIVTSQ status version]: Q8W 62.2/66.0; Q4W 62.0/66.0), treatment acceptance (mean: Q8W 89.3/100; Q4W 91.2/100), and acceptance of injection site reactions (mean [5 = not at all acceptable; 1 = totally acceptable]: Q8W 1.72; Q4W 1.59) at baseline/Week 8 that were maintained over time. Participants without prior CAB + RPV exposure who received Q8W dosing preferred this regimen over oral CAB + RPV (98%, n = 300/306). Among those with prior Q4W exposure, 94% (n = 179/191) preferred Q8W dosing versus Q4W dosing (3%, n = 6/191) or oral CAB + RPV (2%, n = 4/191).

CONCLUSIONS

Both long-acting regimens provided high treatment satisfaction and acceptance, irrespective of prior CAB + RPV exposure, with most participants preferring Q8W dosing over both the Q4W regimen and their previous daily oral regimen. The PRO data collected at Week 48 support the therapeutic potential of CAB + RPV LA.

FUNDING

ViiV Healthcare and Janssen.

TRIAL REGISTRATION

ATLAS-2M: ClinicalTrials.gov NCT03299049, registered October 2, 2017.

Long-Acting Injectable Cabotegravir + Rilpivirine for HIV Maintenance Therapy: Week 48 Pooled Analysis of Phase 3 ATLAS and FLAIR Trials

BACKGROUND

Long-acting (LA) injectable regimens are a potential therapeutic option in people living with HIV-1.

SETTING

ATLAS (NCT02951052) and FLAIR (NCT02938520) were 2 randomized, open-label, multicenter, multinational phase 3 studies.

METHODS

Adult participants with virologic suppression (plasma HIV-1 RNA <50 copies/mL) were randomized (1:1) to continue with their current antiretroviral regimen (CAR) or switch to the long-acting (LA) regimen of cabotegravir (CAB) and rilpivirine (RPV). In the LA arm, participants initially received oral CAB + RPV once-daily for 4 weeks to assess individual safety and tolerability, before starting monthly injectable therapy. The primary endpoint of this combined analysis was antiviral efficacy at week 48 (FDA Snapshot algorithm: noninferiority margin of 4% for HIV-1 RNA ≥50 copies/mL). Safety, tolerability, and confirmed virologic failure (2 consecutive plasma HIV-1 RNA ≥200 copies/mL) were secondary endpoints.

RESULTS

The pooled intention-to-treat exposed population included 591 participants in each arm [28% women (sex at birth), 19% aged ≥50 years]. Noninferiority criteria at week 48 were met for the primary (HIV-1 RNA ≥50 copies/mL) and key secondary (HIV-1 RNA <50 copies/mL) efficacy endpoints. Seven individuals in each arm (1.2%) developed confirmed virologic failure; 6/7 (LA) and 3/7 (CAR) had resistance-associated mutations. Most LA recipients (83%) experienced injection site reactions, which decreased in incidence over time. Injection site reactions led to the withdrawal of 6 (1%) participants. The serious adverse event rate was 4% in each arm.

CONCLUSION

This combined analysis demonstrates monthly injections of CAB + RPV LA were noninferior to daily oral CAR for maintaining HIV-1 suppression.

Multi-level considerations for optimal implementation of long-acting injectable antiretroviral therapy to treat people living with HIV: perspectives of health care providers participating in phase 3 trials

Background

Long-acting injectable antiretroviral therapy (LA ART) has been shown to be non-inferior to daily oral ART, with high patient satisfaction and preference to oral standard of care in research to date, and has recently been approved for use in the United States and Europe. This study examined the perspectives of health care providers participating in LA ART clinical trials on potential barriers and solutions to LA ART roll-out into real world settings.

Methods

This analysis draws on two data sources: (1) open-ended questions embedded in a structured online survey of 329 health care providers participating in the ATLAS-2 M trial across 13 countries; and (2) in-depth interviews with 14 providers participating in FLAIR/ ATLAS/ATLAS-2 M trials in the United States and Spain. Both assessments explored provider views and clinic dynamics related to the introduction of LA ART and were analyzed using thematic content analysis. The Consolidated Framework for Implementation Research (CFIR) was drawn on as the conceptual framework underpinning development of a model depicting study findings.

Results

Barriers and proposed solutions to LA ART implementation were identified at the individual, clinic and health system levels. Provider perceptions of patient level barriers included challenges with adhering to frequent injection appointments and injection tolerability. Proposed solutions included patient education, having designated staff for clinic visit retention, and clinic flexibility with appointment scheduling. The main provider concern was identifying appropriate candidates for LA ART; proposed solutions focused on patient provider communication and decision making. Clinic level barriers included the need for additional skilled individuals to administer injections, shifts in workflow as demand increases and the logistics of cold-chain storage. Proposed solutions included staff hiring and training, strategic planning around workflow and logistics, and the possibility of offering injections in other settings, including the home. Health system level barriers included cost and approvals from national regulatory bodies. Potential solutions included governments subsidizing treatment, ensuring cost is competitive with oral ART, and offering co-pay assistance.

Conclusions

Results suggest the importance of multi-level support systems to optimize patient-provider communication and treatment decision-making; clinic staffing, workflow, logistics protocols and infrastructure; and cost-related factors within a given health system.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12913-021-06214-9.

A Concept Evaluation Study of a New Combination Bictegravir plus Tenofovir Alafenamide Nanoformulation with Prolonged Sustained-Drug-Release Potency for HIV-1 Preexposure Prophylaxis

The antiretroviral treatment (ART) approach is the best-prescribed approach to date for preexposure prophylaxis (PrEP) for high-risk individuals. However, the daily combination antiretroviral (cARV) regimen has become cumbersome for healthy individuals, leading to nonadherence. Recent surveys showed high acceptance of parenteral sustained-release ART enhancing PrEP adherence. Our approach is to design a parenteral nanoparticle (NP)-based cARV sustained-release (cARV-SR) system as long-acting HIV PrEP. Here, we report a new combination of two potent ARVs (tenofovir alafenamide fumarate [TAF] and bictegravir [BIC]) loaded as a nanoformulation intended as a cARV-SR for PrEP. The BIC+TAF NPs were fabricated by using a standardized in-house methodology. In vitro intracellular kinetics, cytotoxicity, and HIV-1 protection studies demonstrated that BIC+TAF encapsulation prolonged drug retention, reduced drug-associated cytotoxicity, and enhanced HIV protection. In human peripheral blood mononuclear cells, nanoformulated BIC+TAF demonstrated significant (P < 0.05) improvement in the drug's selectivity index by 472 times compared to the BIC+TAF in solution. In vivo pharmacokinetic study of BIC, TAF, and respective drug metabolites in female BALB/c mice after single subcutaneous doses of BIC+TAF NPs demonstrated plasma drug concentrations of BIC and tenofovir above the intracellular 50% inhibitory concentration during the entire 30-day study period and prolonged persistence of both active drugs in the HIV target organs, including the vagina, colon, spleen, and lymph nodes. This report demonstrates that the encapsulation of BIC+TAF in a nanoformulation improved its therapeutic selectivity and the in vivo pharmacokinetics of free drugs. Based on these preliminary studies, we hypothesize that cARV-SR has potential as an innovative once-monthly delivery treatment for PrEP.

Long-acting injectable HIV therapies: the next frontier: Republication

PURPOSE OF REVIEW

There has been significant development of long-acting injectable therapy for the management of HIV in recent years that has the potential to revolutionise HIV care as we know it. This review summarises the data and outlines the potential challenges in the field of long-acting antiretroviral therapy (ART).

RECENT FINDINGS

In recent years, monthly and two monthly long-acting injectable ART in the form of cabotegravir and rilpivirine has shown safety and efficacy in large-scale phase 3 randomised control trials. Also, agents with novel mechanisms of action, such as Lenacapavir, have been tested in early-phase studies and are currently being tested in phase 2-3 clinical trials; if successful, this may allow six-monthly dosing schedules.

SUMMARY

However, despite evidence that suggests that these therapies are efficacious and acceptable to patients, the challenge of integrating these agents into our current healthcare infrastructure and making these novel agents cost-effective and available to the populations most likely to benefit remains. The next frontier for long-acting therapy will be to introduce these agents in a real-world setting ensuring that the groups most in need of long-acting therapy are not left behind.

The Promise of Improved Adherence With Long-Acting Antiretroviral Therapy: What Are the Data?

As with other chronic conditions, adherence to daily medications remains a challenge for many individuals living with HIV due to structural, behavioral, and social barriers. Unfortunately, high levels of adherence to antiretroviral therapy are required to maintain virologic suppression. Alternative approaches are being explored to decrease the burden of daily pill administration, including long-acting injectable, oral, and implantable products. Phase 3 data support the efficacy of nanoformulated injectable cabotegravir and rilpivirine for HIV treatment in patients with undetectable viremia, but we have yet to learn how this strategy may benefit those with medication adherence challenges. Despite this, the affected community and HIV providers are very interested in exploring the role of long-acting therapies to address some types of barriers to medication adherence. This review summarizes available information about the potential for long-acting therapy to improve adherence for some patients and outlines associated opportunities and challenges with the implementation of long-acting therapy for the treatment and prevention of HIV.

Patient-Reported Outcomes in ATLAS and FLAIR Participants on Long-Acting Regimens of Cabotegravir and Rilpivirine Over 48 Weeks

The phase 3 ATLAS and FLAIR studies demonstrated that maintenance with Long-Acting (LA) intramuscular cabotegravir and rilpivirine is non-inferior in efficacy to current antiretroviral (CAR) oral therapy. Both studies utilized Patient-Reported Outcome instruments to measure treatment satisfaction (HIVTSQ) and acceptance (ACCEPT general domain), health status (SF-12), injection tolerability/acceptance (PIN), and treatment preference. In pooled analyses, LA-treated patients (n = 591) demonstrated greater mean improvements from baseline than the CAR group (n = 591) in treatment satisfaction (Week 44, + 3.9 vs. +0.5 HIVTSQs-points; p < 0.001) and acceptance (Week 48, +8.8 vs. +2.0 ACCEPT-points; p < 0.001). The acceptability of injection site reactions (PIN) significantly improved from week 5 (2.10 points) to week 48 (1.62 points; p < 0.001). In both studies, ≥ 97% of LA group participants with recorded data preferred LA treatment compared with prior oral therapy. These results further support the potential of a monthly injectable option for people living with HIV seeking an alternative to daily oral treatment.

Long-acting drugs and formulations for the treatment and prevention of HIV infection

Long-acting and extended-release formulations represent one of the most important approaches to improving the treatment and prevention of chronic HIV infection. Long-acting small molecules and monoclonal antibodies have demonstrated potent anti-HIV activity in early- and late-stage clinical trials. Strategies to manage toxicity and falling drug concentrations after missed doses, as well as primary and secondary resistance to current drugs and monoclonal antibodies are important considerations. Long-acting injectable nanoformulations of the integrase inhibitor cabotegravir and the non-nucleoside reverse transcriptase inhibitor rilpivirine were safe, well tolerated and efficacious in large randomised phase 3 studies. Regulatory approval for this two-drug combination for HIV maintenance therapy was granted in Canada in 2020 and is expected in the USA during 2021. 4'-Ethynyl-2-fluoro-2'-deoxyadenosine (islatravir) is a novel nucleoside reverse transcriptase inhibitor in clinical development as a long-acting oral drug and as a long-acting subcutaneous polymer implant. GS-6207 is a novel HIV capsid inhibitor that is injected subcutaneously every 3 months. Broadly-neutralising monoclonal antibodies have potent antiviral activity in early human trials, however there is substantial baseline resistance and rapid development of resistance to these antibodies if used as monotherapy. Limitations of these antiretroviral approaches include management of toxicities and prevention of drug resistance when these drugs are discontinued and drug concentrations are slowly reduced over time. These approaches appear to be especially attractive for patients complaining of pill fatigue and for those experiencing HIV-associated stigma. As these formulations are shown to be safe, well tolerated and economical, they are likely to gain broader appeal.

"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.

Acceptability and preferences for long-acting antiretroviral formulations among people with HIV infection

The study evaluates the acceptability and preferences for long-acting antiretroviral therapy (LA-ART) among a diverse cohort of people with HIV infection (PWH). It consists of a self-administered survey and chart review of PWH presenting to an HIV clinic in Houston, Texas, between February and June 2018; 374 participants were included; 61% indicated that they were likely or very likely to use LA-ART formulations. When asked about preference, 41% preferred pills, 40% preferred injections, and 18% preferred an implant. The most common benefit reported was eliminating the need to remember taking daily HIV pills (74%); 43% were worried that LA-ART will not be as effective as pills. Participants with a college degree, men who have sex with men, and ART-experienced were more willing to use LA-ART. Participants who reported poor or fair health, or who screened positive for depression or anxiety were significantly less willing to use LA-ART. The likelihood of using LA-ART did not correlate with self-reported adherence and HIV suppression. Patients with difficulty scheduling and attending clinic visits preferred injections and implant over pills. Most participants indicated a willingness to use new LA ART formulations. However, 41% still prefers pills, and those more interested in LA-ART were not less adherent.

The Potential of Long-Acting, Tissue-Targeted Synthetic Nanotherapy for Delivery of Antiviral Therapy Against HIV Infection

Oral administration of a combination of two or three antiretroviral drugs (cART) has transformed HIV from a life-threatening disease to a manageable infection. However, as the discontinuation of therapy leads to virus rebound in plasma within weeks, it is evident that, despite daily pill intake, the treatment is unable to clear the infection from the body. Furthermore, as cART drugs exhibit a much lower concentration in key HIV residual tissues, such as the brain and lymph nodes, there is a rationale for the development of drugs with enhanced tissue penetration. In addition, the treatment, with combinations of multiple different antiviral drugs that display different pharmacokinetic profiles, requires a strict dosing regimen to avoid the emergence of drug-resistant viral strains. An intriguing opportunity lies within the development of long-acting, synthetic scaffolds for delivering cART. These scaffolds can be designed with the goal to reduce the frequency of dosing and furthermore, hold the possibility of potential targeting to key HIV residual sites. Moreover, the synthesis of combinations of therapy as one molecule could unify the pharmacokinetic profiles of different antiviral drugs, thereby eliminating the consequences of sub-therapeutic concentrations. This review discusses the recent progress in the development of long-acting and tissue-targeted therapies against HIV for the delivery of direct antivirals, and examines how such developments fit in the context of exploring HIV cure strategies.

Advances in Long-Acting Agents for the Treatment of HIV Infection

Long-acting antiretroviral therapy holds the promise of new options for human immunodeficiency virus (HIV) treatment beyond the current paradigm of daily oral pills. Of particular interest is their potential role in addressing challenges with adherence to oral therapy and treatment fatigue. Similar to other conditions where long-acting formulations have proven effective such as contraception and mental health, long-acting antiretroviral therapy could provide additional treatment choices to people with HIV. This review provides an outline of the current landscape of long-acting antiretroviral therapy for HIV treatment, both approved and under development, including cabotegravir, rilpivirine, leronlimab, islatravir, albuvirtide, GS-6207, and broadly neutralizaing antibodies. However, there are a number of research gaps for long-acting antiretroviral therapy including issues regarding resistance and understudied populations, and this review highlights some of the challenges that will need to be addressed for clinical implementation of these novel treatment modalities.

Long-Acting Cabotegravir and Rilpivirine after Oral Induction for HIV-1 Infection

BACKGROUND

Long-acting injectable regimens may simplify therapy for patients with human immunodeficiency virus type 1 (HIV-1) infection.

METHODS

We conducted a phase 3, randomized, open-label trial in which adults with HIV-1 infection who had not previously received antiretroviral therapy were given 20 weeks of daily oral induction therapy with dolutegravir-abacavir-lamivudine. Participants who had an HIV-1 RNA level of less than 50 copies per milliliter after 16 weeks were randomly assigned (1:1) to continue the current oral therapy or switch to oral cabotegravir plus rilpivirine for 1 month followed by monthly injections of long-acting cabotegravir plus rilpivirine. The primary end point was the percentage of participants who had an HIV-1 RNA level of 50 copies per milliliter or higher at week 48 (Food and Drug Administration snapshot algorithm).

RESULTS

At week 48, an HIV-1 RNA level of 50 copies per milliliter or higher was found in 6 of 283 participants (2.1%) who received long-acting therapy and in 7 of 283 (2.5%) who received oral therapy (adjusted difference, -0.4 percentage points; 95% confidence interval [CI], -2.8 to 2.1), a result that met the criterion for noninferiority for the primary end point (margin, 6 percentage points). An HIV-1 RNA level of less than 50 copies per milliliter at week 48 was found in 93.6% who received long-acting therapy and in 93.3% who received oral therapy (adjusted difference, 0.4 percentage points; 95% CI, -3.7 to 4.5), a result that met the criterion for noninferiority for this end point (margin, -10 percentage points). Of the participants who received long-acting therapy, 86% reported injection-site reactions (median duration, 3 days; mild or moderate severity, 99% of cases); 4 participants withdrew from the trial for injection-related reasons. Grade 3 or higher adverse events and events that met liver-related stopping criteria occurred in 11% and 2%, respectively, who received long-acting therapy and in 4% and 1% who received oral therapy. Treatment satisfaction increased after participants switched to long-acting therapy; 91% preferred long-acting therapy at week 48.

CONCLUSIONS

Therapy with long-acting cabotegravir plus rilpivirine was noninferior to oral therapy with dolutegravir-abacavir-lamivudine with regard to maintaining HIV-1 suppression. Injection-site reactions were common. (Funded by ViiV Healthcare and Janssen; FLAIR ClinicalTrials.gov number, NCT02938520.).

Long-Acting Cabotegravir and Rilpivirine for Maintenance of HIV-1 Suppression

BACKGROUND

Simplified regimens for the treatment of human immunodeficiency virus type 1 (HIV-1) infection may increase patient satisfaction and facilitate adherence.

METHODS

In this phase 3, open-label, multicenter, noninferiority trial involving patients who had had plasma HIV-1 RNA levels of less than 50 copies per milliliter for at least 6 months while taking standard oral antiretroviral therapy, we randomly assigned participants (1:1) to either continue their oral therapy or switch to monthly intramuscular injections of long-acting cabotegravir, an HIV-1 integrase strand-transfer inhibitor, and long-acting rilpivirine, a nonnucleoside reverse-transcriptase inhibitor. The primary end point was the percentage of participants with an HIV-1 RNA level of 50 copies per milliliter or higher at week 48, determined with the use of the Food and Drug Administration snapshot algorithm.

RESULTS

Treatment was initiated in 308 participants per group. At week 48, HIV-1 RNA levels of 50 copies per milliliter or higher were found in 5 participants (1.6%) receiving long-acting therapy and in 3 (1.0%) receiving oral therapy (adjusted difference, 0.6 percentage points; 95% confidence interval [CI], -1.2 to 2.5), a result that met the criterion for noninferiority for the primary end point (noninferiority margin, 6 percentage points). An HIV-1 RNA level of less than 50 copies per milliliter at week 48 was found in 92.5% of participants receiving long-acting therapy and in 95.5% of those receiving oral therapy (adjusted difference, -3.0 percentage points; 95% CI, -6.7 to 0.7), a result that met the criterion for noninferiority for this end point (noninferiority margin, -10 percentage points). Virologic failure was confirmed in 3 participants who received long-acting therapy and 4 participants who received oral therapy. Adverse events were more common in the long-acting-therapy group and included injection-site pain, which occurred in 231 recipients (75%) of long-acting therapy and was mild or moderate in most cases; 1% withdrew because of this event. Serious adverse events were reported in no more than 5% of participants in each group.

CONCLUSIONS

Monthly injections of long-acting cabotegravir and rilpivirine were noninferior to standard oral therapy for maintaining HIV-1 suppression. Injection-related adverse events were common but only infrequently led to medication withdrawal. (Funded by ViiV Healthcare and Janssen; ATLAS ClinicalTrials.gov number, NCT02951052.).

Addressing the global burden of hepatitis B virus while developing long-acting injectables for the prevention and treatment of HIV

The first long-acting formulations of HIV drugs are undergoing regulatory review for use in maintenance of viral suppression in people with HIV. Although these novel drug formulations could contribute greatly to HIV treatment and prevention efforts, their lack of activity against hepatitis B virus (HBV) could limit their global impact, particularly in populations with high burdens of both HIV and HBV. An urgent need for greater investment in research and development of long-acting drugs with dual activity against HIV and HBV exists. Access to long-acting HIV drug formulations with dual activity against HBV would be transformative and have a great impact on efforts to prevent, treat, and eradicate both of these important global epidemics.

Synthesis and Characterization of Long-Acting Darunavir Prodrugs

Antiretroviral therapy (ART) has improved the quality of life in patients infected with HIV-1. However, complete viral suppression within anatomical compartments remains unattainable. This is complicated by adverse side effects and poor adherence to lifelong therapy leading to the emergence of viral drug resistance. Thus, there is an immediate need for cellular and tissue-targeted long-acting (LA) ART formulations. Herein, we describe two LA prodrug formulations of darunavir (DRV), a potent antiretroviral protease inhibitor. Two classes of DRV prodrugs, M1DRV and M2DRV, were synthesized as lipophilic and hydrophobic prodrugs and stabilized into aqueous suspensions designated NM1DRV and NM2DRV. The formulations demonstrated enhanced intracellular prodrug levels with sustained drug retention and antiretroviral activities for 15 and 30 days compared to native DRV formulation in human monocyte-derived macrophages. Pharmacokinetics tests of NM1DRV and NM2DRV administered to mice demonstrated sustained drug levels in blood and tissues for 30 days. These data, taken together, support the idea that LA DRV with sustained antiretroviral responses through prodrug nanoformulations is achievable.

Interest of Youth Living With HIV in Long-Acting Antiretrovirals

OBJECTIVES

This study's primary objective was to characterize attitudes to long-acting antiretrovirals (LAARV), among youth aged 13-24 years living with perinatally acquired HIV and nonperinatally acquired HIV. Secondary objectives included: assessing whether those with detectable HIV RNA PCR viral load had higher enthusiasm for LAARV compared to those with suppressed viral load, and examining characteristics associated with LAARV enthusiasm.

METHODS

A cross-sectional survey of 303 youth living with HIV (YHIV) followed at 4 pediatric/adolescent HIV clinics in the United States was performed to determine interest in LAARV, using a modified survey instrument previously used in adults. Interest in LAARV across groups was compared. Poisson regression with robust variance was used to determine the impact of various characteristics on interest in LAARV.

FINDINGS

Overall, 88% of YHIV reported probable or definite willingness to use LAARV. The enthusiasm level was similar between youth with perinatally acquired HIV and nonperinatally acquired HIV (P = 0.93). Youth with HIV viral load >1000 copies per milliliter had significantly higher interest than youth with suppressed viral load [prevalence ratio 1.12 (95% confidence interval: 1.03 to 1.20); P = 0.005]. Female youth participants who had had past experience with implantable contraceptive methods had a significantly higher interest in LAARV (100% vs. 85.5%; P = 0.002). Proportion of respondents endorsing definite willingness to use was significantly higher with decreased injection frequency compared with increased injection frequency.

INTERPRETATION

YHIV at 4 urban US pediatric/adolescent HIV clinics had high levels of enthusiasm for LAARV. LAARV should be given high priority as a potentially viable treatment option to improve clinical outcomes in YHIV.

From design to the clinic: practical guidelines for translating cardiovascular nanomedicine

Cardiovascular diseases (CVD) account for nearly half of all deaths in Europe and almost 30% of global deaths. Despite the improved clinical management, cardiovascular mortality is predicted to rise in the next decades due to the increasing impact of aging, obesity, and diabetes. The goal of emerging cardiovascular nanomedicine is to reduce the burden of CVD using nanoscale medical products and devices. However, the development of novel multicomponent nano-sized products poses multiple technical, ethical, and regulatory challenges, which often obstruct their road to successful approval and use in clinical practice. This review discusses the rational design of nanoparticles, including safety considerations and regulatory issues, and highlights the steps needed to achieve efficient clinical translation of promising nanomedicinal products for cardiovascular applications.

Modern Human Immunodeficiency Virus Therapy: Progress and Prospects

Safe and effective lifelong treatment to control human immunodeficiency virus (HIV) infection is one of the greatest scientific and public health achievements of the past century. The majority of infected individuals able to maintain a daily oral regimen now have a normal or near-normal life expectancy. More than 30 approved drugs and dozens of formulations have produced thousands of possible drug combinations used clinically in the past, but today most patients receive only a handful of high priority and rigorously tested regimens. Unique features of antiretroviral therapy include the need for lifelong treatment to control virus replication and the possibility of rapid emergence of permanent drug resistance if these agents are not properly used. Although three-drug combination oral regimens have radically altered the course of this epidemic, the future will include long-acting injectable and implantable drugs and devices to treat and prevent infection.

Modelling the intradermal delivery of microneedle array patches for long-acting antiretrovirals using PBPK

INTRODUCTION

Existing HIV therapy using oral antiretrovirals (ARVs) can result in pill fatigue and sub-optimal adherence. Microneedle array patches (MAPs) offer non-invasive, blood-free and painless drug delivery, and may improve patient adherence. The objective of this study was to develop a novel physiologically-based pharmacokinetic (PBPK) model to simulate the systemic pharmacokinetics of cabotegravir and rilpivirine MAPs using the intradermal route.

METHODS

The developed PBPK models were qualified against observed pharmacokinetic data after intramuscular (IM) and intradermal administration of long-acting nanoformulated rilpivirine to rats, and for IM administration of both drugs to healthy adults. Qualified models were then utilised to estimate suitable MAP characteristics (e.g. nanoformulation dose and release rates) and inform dosing strategies to maintain plasma concentrations above target trough concentrations for the designated dosing interval.

RESULTS

PBPK models simulated q4-weekly loading and maintenance doses of 360 mg and 180 mg for long-acting formulated cabotegravir between the release rates of 1 × 10^-3-3 × 10^-3h^-1 and 1 × 10^-3-1.5 × 10^-3h^-1 respectively, for a 70 kg adult. Estimated patch size was 60 cm² for a 360 mg dose of cabotegravir. For q4-weekly dosing, rilpivirine required a 1080 mg loading dose and a 540 mg maintenance dose with release rates of 1.5 × 10^-3-2.5 × 10^-3h^-1 and 5 × 10^-4-1 × 10^-3h^-1, respectively. Weekly dosing was also evaluated to assess the potential application from a smaller patch size. The ability to self-administer via a patch that is only left in place for a short duration makes longer durations less important than for some other long-acting approaches. Weekly cabotegravir required 60 mg between release rates 7 × 10^-3-9 × 10^-3h^-1 and rilpivirine required 270 mg and 180 mg respectively between release rates of 7 × 10^-3-9 × 10^-3h^-1.

DISCUSSION

This model estimated optimal dose and release rates for cabotegravir and rilpivirine MAPs. Our approach provides a computational platform to support rational development of intradermal administration strategies to tackle problems associated with chronic oral ARV administration.

Creation of a long-acting rilpivirine prodrug nanoformulation

Antiretroviral therapy requires lifelong daily dosing to attain viral suppression, restore immune function, and improve quality of life. As a treatment alternative, long-acting (LA) antiretrovirals can sustain therapeutic drug concentrations in blood for prolonged time periods. The success of recent clinical trials for LA parenteral cabotegravir and rilpivirine highlight the emergence of these new therapeutic options. Further optimization can improve dosing frequency, lower injection volumes, and facilitate drug-tissue distributions. To this end, we report the synthesis of a library of RPV prodrugs designed to sustain drug plasma concentrations and improved tissue biodistribution. The lead prodrug M3RPV was nanoformulated into the stable LA injectable NM3RPV. NM3RPV treatment led to RPV plasma concentrations above the protein-adjusted 90% inhibitory concentration for 25 weeks with substantial tissue depots after a single intramuscular injection in BALB/cJ mice. NM3RPV elicited 13- and 26-fold increases in the RPV apparent half-life and mean residence time compared to native drug formulation. Taken together, proof-of-concept is provided that nanoformulated RPV prodrugs can extend the apparent drug half-life and improve tissue biodistribution. These results warrant further development for human use.

Synthesis and characterization of a long-acting emtricitabine prodrug nanoformulation

Purpose

A palmitoylated prodrug of emtricitabine (FTC) was synthesized to extend the drug’s half-life, antiretroviral activities and biodistribution.

Methods

A modified FTC prodrug (MFTC) was synthesized by palmitoyl chloride esterification. MFTC’s chemical structure was evaluated by nuclear magnetic resonance. The created hydrophobic prodrug nanocrystals were encased into a poloxamer surfactant and the pharmacokinetics (PK), biodistribution and antiretroviral activities of the nanoformulation (NMFTC) were assessed. The conversion of MFTC to FTC triphosphates was evaluated.

Results

MFTC coated with poloxamer formed stable nanocrystals (NMFTC). NMFTC demonstrated an average particle size, polydispersity index and zeta potential of 350 nm, 0.24 and −20 mV, respectively. Drug encapsulation efficiency was 90%. NMFTC was readily taken up by human monocyte-derived macrophages yielding readily detected intracellular FTC triphosphates and an extended PK profile.

Conclusion

NMFTC shows improved antiretroviral activities over native FTC. This is coordinate with its extended apparent half-life. The work represents an incremental advance in the development of a long-acting FTC formulation.

Nanotechnology approaches for delivery of cytochrome P450 substrates in HIV treatment

Introduction: Antiretroviral therapy (ART) has led to a significant reduction in HIV-1 morbidity and mortality. Many antiretroviral drugs (ARVs) are metabolized by cytochrome P450 (CYP) pathway, and the majority of these drugs are also either CYP inhibitors or inducers and few possess both activities. These CYP substrates, when used for HIV treatment in the conventional dosage form, have limitations such as low systemic bioavailability, potential drug-drug interactions, and short half-lives. Thus, an alternative mode of delivery is needed in contrast to conventional ARVs. Areas covered: In this review, we summarized the limitations of conventional ARVs in HIV treatment, especially for ARVs which are CYP substrates. We also discussed the preclinical and clinical studies using the nanotechnology strategy to overcome the limitations of these CYP substrates. The preclinical studies and clinical studies published from 2000 to February 2019 were discussed. Expert opinion: Since preclinical and clinical studies for prevention and treatment of HIV using nanotechnology approaches have shown considerable promise in recent years, nanotechnology could become an alternative strategy for daily oral therapy as a future treatment.

Long-Acting Injectable Statins-Is It Time for a Paradigm Shift?

In recent years, advances in pharmaceutical processing technologies have resulted in development of medicines that provide therapeutic pharmacokinetic exposure for a period ranging from weeks to months following a single parenteral administration. Benefits for adherence, dose and patient satisfaction have been witnessed across a range of indications from contraception to schizophrenia, with a range of long-acting medicines also in development for infectious diseases such as HIV. Existing drugs that have successfully been formulated as long-acting injectable formulations have long pharmacokinetic half-lives, low target plasma exposures, and low aqueous solubility. Of the statins that are clinically used currently, atorvastatin, rosuvastatin, and pitavastatin may have compatibility with this approach. The case for development of long-acting injectable statins is set out within this manuscript for this important class of life-saving drugs. An overview of some of the potential development and implementation challenges is also presented.

The Promise of Long-Acting Antiretroviral Therapies: From Need to Manufacture

Antiretroviral therapy has transformed human immunodeficiency virus infections from certain death to a manageable chronic disease. Achieving strict adherence to drug regimens that limit toxicities and viral resistance is an achievable goal. Success is defined by halting viral transmission and by continuous viral restriction. A step towards improving treatment outcomes is in long-acting antiretrovirals. While early results remain encouraging there remain opportunities for improvement. These rest, in part, on the required large drug dosing volumes, local injection-site reactions, and frequency of injections. Thus, implantable devices and long-acting parenteral prodrugs have emerged which may provide more effective clinical outcomes. The recent successes in transforming native antiretrovirals into lipophilic and hydrophobic prodrugs stabilized into biocompatible surfactants can positively affect both. Formulating antiretroviral prodrugs demonstrates improvements in cell and tissue targeting, in drug-dosing intervals, and in the administered volumes of nanosuspensions. As such, the newer formulations also hold the potential to suppress viral loads beyond more conventional therapies with the ultimate goal of HIV-1 elimination when combined with other modalities.

Long-acting formulations for the treatment of latent tuberculous infection: opportunities and challenges

Long-acting/extended-release drug formulations have proved very successful in diverse areas of medicine, including contraception, psychiatry and, most recently, human immunodeficiency virus (HIV) disease. Though challenging, application of this technology to anti-tuberculosis treatment could have substantial impact. The duration of treatment required for all forms of tuberculosis (TB) put existing regimens at risk of failure because of early discontinuations and treatment loss to follow-up. Long-acting injections, for example, administered every month, could improve patient adherence and treatment outcomes. We review the state of the science for potential long-acting formulations of existing tuberculosis drugs, and propose a target product profile for new formulations to treat latent tuberculous infection (LTBI). The physicochemical properties of some anti-tuberculosis drugs make them unsuitable for long-acting formulation, but there are promising candidates that have been identified through modeling and simulation, as well as other novel agents and formulations in preclinical testing. An efficacious long-acting treatment for LTBI, particularly for those co-infected with HIV, and if coupled with a biomarker to target those at highest risk for disease progression, would be an important tool to accelerate progress towards TB elimination.