Single-Tablet Regimens for the Treatment of HIV-1 Infection

Real-Life Experience With Bictegravir/Emtricitabine/Tenofovir Alafenamide in Turkey

INTRODUCTION

Single-tablet regimens (STRs) can increase treatment success and even improve the quality of life of human immunodeficiency virus (HIV) patients. In this study, we aim to analyze the real-life efficacy and tolerability data of people living with HIV (PLWH) initiated on or switched to bictegravir/emtricitabine/tenofovir alafenamide fumarate (BIC/FTC/TAF) as first-line treatment.

MATERIALS AND METHODS

This retrospective analysis was performed in HIV-1-positive patients who were initiated BIC/FTC/TAF in the HIV clinic between June 2020 and June 2022. Patients who received BIC/FTC/TAF for at least 12 months were included in this study. Virological suppression, laboratory parameters, side effects, and immunological response were analyzed at one, three, six, nine, and 12 months.

RESULTS

A total of 116 patients, 66 (56.9%) treatment-experienced and 50 (43.1%) naive, were evaluated within the scope of the study. In the naive patient group, baseline HIV-RNA, CD4+ and CD8+ T cell counts, CD4/CD8 ratio, and estimated glomerular filtration rate (eGFR) values were significantly different in different follow-up months. The number of patients with HIV-1 RNA levels below 50 copies/mL was 55.9% in the first month, 73.7% in the third month, 90.2% in the sixth month, and 100% in the ninth and 12th months.

CONCLUSION

In our real-life observational study, BIC/FTC/TAF treatment achieved rapid viral suppression, maintained viral suppression in virally suppressed patients, and was effective for immunological recovery in both treatment-experienced and naive HIV patients. No serious side effects were observed. Our study has proved the potential of BIC/FTC/TAF as an important option in the treatment of HIV patients.

Effect of single tablet regimen on prescription trends for treatment-naïve patients with HIV/AIDS in Korea

Single-tablet regimens (STRs) should be considered for patients with HIV/AIDS to increase medication compliance and improve clinical outcomes. This study compared variations in the prescription trends between STRs and multiple-tablet regimens (MTRs) for treatment-naïve patients with HIV/AIDS after the approval of the new STRs, a proxy indicator for improvement in medication adherence. The medical and pharmacy claim data were retrospectively obtained from the Health Insurance Review and Assessment service, which contains basic information on the patients' sociodemographic characteristics and treatment information for the entire Korean population. From 2013 to 2018, a total of 6737 patients with HIV/AIDS were included. Most patients were men (92.8%, n = 6251) and insured through the National Health Insurance (95.1%, n = 6410). The mean number of pills in their antiretroviral treatment regimens decreased from 2.8 ± 1.2 in 2013 to 1.2 ± 1.0 in 2018. After the first STR (EVG/c/TDF/FTC) was approved in 2014, prescription transitions from MTR to STR were observed among more than 38% of patients. In 2018, most treatment-naïve patients were prescribed STRs (91.2%). There was a time lag for STR prescription trends in non-metropolitan hospitals compared with those in metropolitan cities. Our data provide a valuable perspective for evaluating ART regimen prescription patterns on a national scale.

Covalent Inhibition of Wild-Type HIV-1 Reverse Transcriptase Using a Fluorosulfate Warhead

Covalent inhibitors of wild-type HIV-1 reverse transcriptase (CRTIs) are reported. Three compounds derived from catechol diether non-nucleoside inhibitors (NNRTIs) with addition of a fluorosulfate warhead are demonstrated to covalently modify Tyr181 of HIV-RT. X-ray crystal structures for complexes of the CRTIs with the enzyme are provided, which fully demonstrate the covalent attachment, and confirmation is provided by appropriate mass shifts in ESI-TOF mass spectra. The three CRTIs and six noncovalent analogues are found to be potent inhibitors with both IC50 values for in vitro inhibition of WT RT and EC50 values for cytopathic protection of HIV-1-infected human T-cells in the 5-320 nM range.

An evaluation of cabotegravir for HIV treatment and prevention

Introduction: Oral pre-exposure prophylaxis (PrEP) and antiretroviral therapy (ART) represent the cornerstones of HIV infection prevention and treatment. However, despite their high efficacy, the need to take daily oral pill(s) negatively impacts long-term patient adherence. In some cases, it can also be associated with drug-drug interactions and adverse gastrointestinal effects, as well as being a constant reminder to individuals of their HIV status. The availability of long-acting non-orally administered antiretroviral drugs could, therefore, be extremely useful. Cabotegravir (CAB) is a second-generation integrase strand transfer inhibitor, characterized by a relatively high genetic barrier and good antiretroviral potency, which is administrable as a long-acting injectable suspension (LAI CAB).Areas covered: The authors present and discuss the efficacy and available safety data of LAI CAB, either when co-administered with rilpivirine (RPV; LAI CAB + RPV) for the treatment of HIV infection, or when used as single agent for PrEP.Expert opinion: Cabotegravir has the potential to play a primary role in the treatment and prevention of HIV infection. The future availability of LAI CAB + RPV and LAI CAB may mark the beginning of an era of LAI ART and PrEP, respectively.

Tenofovir Alafenamide Fumarate Therapy for HIV Treatment: Cardiometabolic and Renal Safety

Antiretroviral treatment based on tenofovir alafenamide fumarate (TAF) is increasingly recommended, as it maintains the viral suppression and improves renal function and bone density in comparison with tenofovir disoproxil fumarate (TDF). We carried out a retrospective cohort study including experienced patients who switched treatment from TDF to TAF. Serum lipids and glucose, renal function, body mass index (BMI), and cardiovascular risk were evaluated before and 3 and 6 months after the initiation of TAF-based treatment. We identified 85 patients on TAF-based treatment. The majority were men (82.9%), smokers (70%), and older than 40 years. Significant increases in lipids and BMI were noted, but cardiovascular risk remained <7.5%. Renal function remained normal with a notable improvement among patients with renal impairment. These results suggest that TAF has no significant effect on glucose and does not meaningfully increase cardiovascular risk, despite an elevation in serum lipids. It also exhibits renal safety. However, the increase of BMI was significant. Further studies are needed to confirm these findings in larger patient series and over longer follow-up periods.

The New NNRTI ACC007 Combined with Lamivudine and Tenofovir Disoproxil Fumarate Show Synergy Anti-HIV Activity In Vitro

BACKGROUND

Acquired immunodeficiency syndrome can hardly be cured currently and people with human immunodeficiency virus (HIV) need lifelong treatment that may result in the emergence of drug resistance which leads to failed treatment. Thus, the development of new anti- HIV drugs and new treatment regimens are necessary.

OBJECTIVE

The aim of this study is to analyze the combined anti-HIV activity of tenofovir disoproxil fumarate, lamivudine and ACC007, a new non-nucleoside reverse transcriptase inhibitor.

METHODS

The antiviral activity of tenofovir disoproxil fumarate, lamivudine and ACC007 alone or in combination against different HIV-1 strains was determined by the detection of HIV-1 p24 level through enzyme-linked immunosorbent assay.

RESULT

ACC007 showed EC50 of nanomolar range (from 3.03 nM to 252.59 nM) against all HIV-1 strains used in this study except the HIV-1A17, with EC50 of 1.57 μM. The combined antiviral activity of ACC007, lamivudine and tenofovir disoproxil fumarate showed synergy antiviral activity against all HIV-1 strains used in this study. The three-drug combination showed moderate synergism against HIV-1A17, HIV-14755-5, HIV-1K103N and HIV-1V106M, with a combination index value ranging from 0.71 to 0.87, and showed synergism against the other HIV-1 strains with combination index value from 0.35 to 0.67. The combination with ACC007 significantly increases the dose reduction index value of lamivudine and tenofovir disoproxil fumarate, compared with two-drug combination.

CONCLUSION

ACC007 exhibits potent antiviral activity alone or with 3TC and TDF, and exerts synergistic effect against all HIV strains used in our investigation in vitro.

Differences in HIV Markers between Infected Individuals Treated with Different ART Regimens: Implications for the Persistence of Viral Reservoirs

In adherent individuals, antiretroviral therapy (ART) suppresses HIV replication, restores immune function, and prevents the development of AIDS. However, ART is not curative and has to be followed lifelong. Persistence of viral reservoirs forms the major obstacle to an HIV cure. HIV latent reservoirs persist primarily by cell longevity and proliferation, but replenishment by residual virus replication despite ART has been proposed as another potential mechanism of HIV persistence. It is a matter of debate whether different ART regimens are equally potent in suppressing HIV replication. Here, we summarized the current knowledge on the role of ART regimens in HIV persistence, focusing on differences in residual plasma viremia and other virological markers of the HIV reservoir between infected individuals treated with combination ART composed of different antiretroviral drug classes.

Bictegravir/Emtricitabine/Tenofovir Alafenamide: A Review in HIV-1 Infection

Bictegravir is a new integrase strand transfer inhibitor (INSTI) with a high genetic barrier to the development of HIV-1 resistance. The drug is co-formulated with the nucleos(t)ide reverse transcriptase inhibitors emtricitabine and tenofovir alafenamide (AF) in a single-tablet regimen (STR) for the once-daily treatment of HIV-1 infection in adults (bictegravir/emtricitabine/tenofovir AF; Biktarvy^®). In phase 3 trials, bictegravir/emtricitabine/tenofovir AF was noninferior to dolutegravir-based therapy (dolutegravir/abacavir/lamivudine or dolutegravir plus emtricitabine/tenofovir AF) in establishing virological suppression in treatment-naïve adults through 96 weeks’ treatment and, similarly, was noninferior to ongoing dolutegravir/abacavir/lamivudine or boosted elvitegravir- or protease inhibitor (PI)-based therapy in preventing virological rebound over 48 weeks in treatment-experienced patients. No resistance emerged to any of the antiretrovirals in the STR. Bictegravir/emtricitabine/tenofovir AF is generally well tolerated, requires no prior HLA-B*5701 testing (making it more suitable for ‘rapid start’ treatment), fulfils the antiretroviral regimen requirement for patients with hepatitis B virus (HBV) co-infection (i.e. contains tenofovir AF and emtricitabine, both of which are active against HBV) and can be used in renally impaired patients with creatinine clearance (CR_CL) ≥ 30 mL/min. Thus, although cost-effectiveness analyses would be beneficial, current data indicate that bictegravir/emtricitabine/tenofovir AF is a convenient initial and subsequent treatment option for adults with HIV-1 infection, including those co-infected with HBV, and provides the first non-pharmacologically boosted, INSTI-based, triple-combination STR suitable for patients with CR_CL 30–50 mL/min.

Darunavir/Cobicistat/Emtricitabine/Tenofovir Alafenamide: A Review in HIV-1 Infection

Darunavir/cobicistat/emtricitabine/tenofovir AF (Symtuza^®) is the first protease inhibitor (PI)-based single-tablet regimen (STR) available for the treatment of adults and adolescents (aged ≥ 12 years) with HIV-1 infection. It combines the PI darunavir (which has a high genetic barrier to resistance) with the pharmacokinetic booster cobicistat and the nucleos(t)ide reverse transcriptase inhibitors emtricitabine and tenofovir alafenamide (tenofovir AF), the latter being associated with less off-target tenofovir exposure than its predecessor tenofovir disoproxil fumarate (tenofovir DF). Over 48 weeks in phase 3 trials, darunavir/cobicistat/emtricitabine/tenofovir AF was noninferior to darunavir/cobicistat plus emtricitabine/tenofovir DF in establishing virological suppression in antiretroviral therapy (ART)-naïve adults and, likewise, was noninferior to an ongoing boosted PI, emtricitabine plus tenofovir DF regimen in preventing virological rebound in virologically-suppressed, ART-experienced adults. Resistance did not emerge to the STR components, with the exception being an emtricitabine resistance-associated mutation (RAM) [M184I/V] in one of seven recipients who experienced virological failure (although M184V was a minority variant at screening in this patient). Darunavir/cobicistat/emtricitabine/tenofovir AF was generally well tolerated, with renal and bone profile improvements but less favourable effects on some lipids versus tenofovir DF-based regimens. Thus, although longer-term and cost-effectiveness data would be beneficial, darunavir/cobicistat/emtricitabine/tenofovir AF is a welcome addition to the STRs available for the treatment of adults and adolescents with HIV-1 infection, being the first to combine the high genetic resistance barrier of darunavir with the renal/bone profile of tenofovir AF, thus expanding the patient population for whom an STR may be suitable.

Comparative study of antiretroviral drug regimens and drug-drug interactions between younger and older HIV-infected patients at a tertiary care teaching hospital in South Korea

Background

With the advent of combination antiretroviral therapy (ART), people living with HIV have lived to older age. So they have experienced age-related illnesses and have taken non-antiretroviral (ARV) medications to manage these illnesses. The aims of this study were to investigate the use patterns of ARV agents in HIV-positive patients by age and to evaluate potential or contraindicated drug-drug interactions (DDIs) between ARV and non-ARV.

Methods

This study was retrospectively conducted with HIV-infected patients receiving ART medications between October 2011 and September 2017 at Chonbuk National University Hospital in South Korea. Data were collected by reviewing patients' electronic medical charts.

Results

Among 207 patients diagnosed with HIV infection, 183 (86.9% males; 104 aged <50 years and 79 aged ≥50 years) were selected based on inclusion criteria. In 2017, the most frequently prescribed ART regimen was nucleoside reverse transcriptase inhibitors (NRTIs)/integrase strand transfer inhibitors (INSTIs; total, 66.3%; <50 years, 36.3%; ≥50 years, 30.0%) followed by NRTIs/protease inhibitors (PIs; total, 23.8%; <50 years, 15.0%; ≥50 years, 8.8%). In 2017, the most frequently prescribed NRTI combination was abacavir/lamivudine (total, 34.4%; <50 years, 20.6%; ≥50 years, 13.8%) followed by tenofovir alafenamide/emtricitabine (FTC; total, 31.3%; <50 years, 16.3%; ≥50 years, 15.0%) and tenofovir disoproxil fumarate/FTC (total, 28.1%; <50 years, 16.9%; ≥50 years, 11.3%). In 2017, elvitegravir (EVG)/cobicistat (COBI; total, 57.1%; <50 years, 30.4%; ≥50 years, 26.8%) was most frequently prescribed followed by dolutegravir (total, 32.1%; <50 years, 19.6%; ≥50 years, 12.5%). Potential or contraindicated DDIs between boosted PIs with ritonavir or EVG/COBI and coprescribed drugs occurred most frequently.

Conclusion

Currently, NRTIs/INSTIs is the most frequently prescribed ARV combination. Abacavir/lamivudine, tenofovir alafenamide/FTC, and tenofovir disoproxil fumarate/FTC are the most used NRTIs, and EVG/COBI followed by dolutegravir is the most prescribed INSTIs. Potential or contraindicated DDIs occur mainly between boosted PIs or EVG/COBI and non-ARV medications.

Avoidable workload of care for patients living with HIV infection in Abidjan, Côte d'Ivoire: A cross-sectional study

OBJECTIVE

People living with HIV infection (PLWHIV) in Sub-Saharan Africa cope with an increasing workload of care (doctor visits, lab tests, medication management, refills, etc.) in a context of poor health service organization. We aimed to describe the workload of care for PLWHIV in Sub-Saharan Africa and assess to what extent simple adjustments in care organization could reduce this workload of care.

METHODS

Adult PLWHIV under antiretroviral treatment for at least 1 year were recruited in three centers (two public, one private) in Abidjan, Côte d'Ivoire. Using methods inspired from sociology, we precisely described all health-related activities (HRAs) performed by patients, in 1 month, in terms of time, money and opportunity costs. Then, we assessed the theoretical avoidable workload of care if patients' visits and tests had been grouped on the same days.

RESULTS

We enrolled 476 PLWHIV in the study. Patients devoted 6.7 hours (SD = 6.3), on average, in HRAs per month and spent 5% (SD = 11) of their monthly revenue, on average, on health activities. However, we found great inter-patient heterogeneity in the mixture of activities performed (managing medications; dietary recommendations; visits, tests, support groups; administrative tasks; etc.) and their time allocation, temporal dispersion and opportunity costs (personal, familial, social or professional costs). For 22% of patients, grouping activities on the same days could reduce both time and cost requirements by 20%.

CONCLUSION

PLWHIV in Côte d'Ivoire have a heavy workload of care. Grouping visits and tests on the same days may be a simple and feasible way to reduce patients' investment of time and money in their care.

HIV Clinical Updates: New Single-Tablet Regimens

OBJECTIVE

To review the pharmacokinetics, safety, common drug-drug interactions (DDIs), and advantages and disadvantages of new single-tablet regimens (STRs) approved since September 2016 for HIV-1 infection.

DATA SOURCES

A search using PubMed was conducted (2004 through May 2018) using the following keywords: single tablet regimen AND HIV. Additionally, a PubMed search was conducted for each individual STR using the generic names of the agents. For specific STRs, additional search terms were added to narrow results. Articles were evaluated for content, and additional references were identified from a review of literature citations. Conference abstracts from national and international HIV conferences were also searched.

STUDY SELECTION AND DATA EXTRACTION

Studies included were published randomized controlled trials and observational studies that evaluated STR approved since September 2016. Relevant conference abstracts were included if the study design was a randomized controlled trial or observational study pertaining to the STRs included.

DATA SYNTHESIS

Four new STRs are available, including the first dual antiretroviral therapy (ART) regimen for virologically suppressed patients. Of the STRs, only 1 is a new molecular entity, and others include new combinations of existing agents that result in distinct advantages and disadvantages. Relevance to Patient Care and Clinical Practice: The treatment of HIV-1 continues to improve with new agents developed rapidly. These agents should be analyzed in regard to efficacy, safety, DDIs, and appropriateness for specific patients on an individual basis.

CONCLUSIONS

STRs and agents in the pipeline continue to simplify ART regimens, increase medication adherence, and minimize toxicities.

From in silico hit to long-acting late-stage preclinical candidate to combat HIV-1 infection

The HIV-1 pandemic affecting over 37 million people worldwide continues, with nearly one-half of the infected population on highly active antiretroviral therapy (HAART). Major therapeutic challenges remain because of the emergence of drug-resistant HIV-1 strains, limitations because of safety and toxicity with current HIV-1 drugs, and patient compliance for lifelong, daily treatment regimens. Nonnucleoside reverse transcriptase inhibitors (NNRTIs) that target the viral polymerase have been a key component of the current HIV-1 combination drug regimens; however, these issues hamper them. Thus, the development of novel more effective NNRTIs as anti-HIV-1 agents with fewer long-term liabilities, efficacy on new drug-resistant HIV-1 strains, and less frequent dosing is crucial. Using a computational and structure-based design strategy to guide lead optimization, a 5 µM virtual screening hit was transformed to a series of very potent nanomolar to picomolar catechol diethers. One representative, compound I, was shown to have nanomolar activity in HIV-1-infected T cells, potency on clinically relevant HIV-1 drug-resistant strains, lack of cytotoxicity and off-target effects, and excellent in vivo pharmacokinetic behavior. In this report, we show the feasibility of compound I as a late-stage preclinical candidate by establishing synergistic antiviral activity with existing HIV-1 drugs and clinical candidates and efficacy in HIV-1-infected humanized [human peripheral blood lymphocyte (Hu-PBL)] mice by completely suppressing viral loads and preventing human CD4⁺ T-cell loss. Moreover, a long-acting nanoformulation of compound I [compound I nanoparticle (compound I-NP)] in poly(lactide-coglycolide) (PLGA) was developed that shows sustained maintenance of plasma drug concentrations and drug efficacy for almost 3 weeks after a single dose.

Role of tenofovir alafenamide (TAF) in the treatment and prophylaxis of HIV and HBV infections

Tenofovir (TFV) is the cornerstone of the treatment and prophylaxis of HIV infections. It has been routinely used in its prodrug form TDF (tenofovir disoproxil fumarate) combined with emtricitabine ((-)FTC) and other antiretroviral agents. TDF has now been replaced by TAF (tenofovir alafenamide) which allows better uptake by the lymphoid tissue. In combination with elvitegravir (E), cobicistat (C), emtricitabine (F), TAF can be advocated as an STR (single tablet regimen, Genvoya®) for the treatment of HIV infections. In this combination, E and C may in the future be replaced by bictegravir. The prophylaxis of HIV infection is momentarily based upon Truvada®, the combination of F with TDF, which in the future may also be replaced by TAF. TAF (Vemlidy®) has also replaced TDF (Viread®) for the treatment of hepatitis B virus (HBV) infections. Both TDF and TAF offer little or no risk for virus-drug resistance. As compared to TDF, TAF limits the risk for nephrotoxicity and loss of bone mineral density. What remains to be settled, however, before the universal use of TAF could be recommended, is its safety during pregnancy and its applicability in the treatment of tuberculosis, in combination with rifampicin.

Covalent inhibitors for eradication of drug-resistant HIV-1 reverse transcriptase: From design to protein crystallography

Development of resistance remains a major challenge for drugs to treat HIV-1 infections, including those targeting the essential viral polymerase, HIV-1 reverse transcriptase (RT). Resistance associated with the Tyr181Cys mutation in HIV-1 RT has been a key roadblock in the discovery of nonnucleoside RT inhibitors (NNRTIs). It is the principal point mutation that arises from treatment of HIV-infected patients with nevirapine, the first-in-class drug still widely used, especially in developing countries. We report covalent inhibitors of Tyr181Cys RT (CRTIs) that can completely knock out activity of the resistant mutant and of the particularly challenging Lys103Asn/Tyr181Cys variant. Conclusive evidence for the covalent modification of Cys181 is provided from enzyme inhibition kinetics, mass spectrometry, protein crystallography, and antiviral activity in infected human T-cell assays. The CRTIs are also shown to be selective for Cys181 and have lower cytotoxicity than the approved NNRTI drugs efavirenz and rilpivirine.