Initial Antiretroviral Therapy in an Integrase Inhibitor Era: Can We Do Better?

A four-drug combination oral tablet of darunavir, cobicistat, emtricitabine, and tenofovir alafenamide for the treatment of HIV-1 infection in adults

INTRODUCTION

Darunavir (DRV)/cobicistat (COBI)/emtricitabine (FTC)/tenofovir alafenamide (TAF) is the only protease inhibitor-based single-tablet regimen (STR) approved for the treatment of HIV infection of adults and pediatric patients weighing at least 40 kg. DRV/COBI/FTC/TAF has demonstrated to be an effective regimen, to have a high genetic barrier to resistance, and to be well tolerated.

AREAS COVERED

The authors summarize the chemistry and pharmacology of DRV, COBI, FTC, and TAF and discuss trials conducted on antiretroviral therapy (ART)-naïve and -experienced people living with HIV designed to evaluate safety, tolerability, and efficacy of the STR. This work also reports studies comparing DRV/COBI/FTC/TAF with competitive agents in real-world settings.

EXPERT OPINION

Despite the availability of newer antiretroviral drugs and strategies in the management of HIV infection, including long-acting therapies, DRV/COBI/FTC/TAF is still considered an alternative regimen for the treatment of ART-naïve adults. DRV/COBI/FTC/TAF is an effective, well-tolerated, and safe antiretroviral regimen and represents a valid option for people who need to switch therapy due to tolerability issues, such as the onset of neuropsychiatric effects related to integrase strand transfer inhibitors, or virological failure.

A CRISPR-Cas Cure for HIV/AIDS

Human immunodeficiency virus (HIV) infections and HIV-induced acquired immunodeficiency syndrome (AIDS) continue to represent a global health burden. There is currently no effective vaccine, nor any cure, for HIV infections; existing antiretroviral therapy can suppress viral replication, but only as long as antiviral drugs are taken. HIV infects cells of the host immune system, and it can establish a long-lived viral reservoir, which can be targeted and edited through gene therapy. Gene editing platforms based on the clustered regularly interspaced palindromic repeat-Cas system (CRISPR-Cas) have been recognized as promising tools in the development of gene therapies for HIV infections. In this review, we evaluate the current landscape of CRISPR-Cas-based therapies against HIV, with an emphasis on the infection biology of the virus as well as the activity of host restriction factors. We discuss the potential of a combined CRISPR-Cas approach that targets host and viral genes to activate antiviral host factors and inhibit viral replication simultaneously. Lastly, we focus on the challenges and potential solutions of CRISPR-Cas gene editing approaches in achieving an HIV cure.

Switching from a Non-Protease inhibitor-Based Regimen To the Fixed Dose Combination of Darunavir/Cobicistat/Emtricitabine/Tenofovir Alafenamide in Clinical Practice

Background

Methods

Results

Conclusion

Weight Gain and Lipid Profile Changes in Koreans with Human Immunodeficiency Virus undergoing Integrase Strand Transfer Inhibitor-Based Regimens

Background

This study explored the relationship between integrase strand transfer inhibitor (INSTI)-based anti-retroviral agents and weight gain over time, and the risk factors for weight gain in Korean people living with human immunodeficiency virus (PLWH).

Materials and Methods

The study was conducted retrospectively in PLWHs 18 years of age or older who took one of three INSTI-based single-tablet regimens (STRs) (tenofovir disoproxil fumarate/emtricitabine/elvitegravir/cobicistat [TDF/F/EVG/c], tenofovir alafenamide/emtricitabine/elvitegravir/cobicistat [TAF/F/EVG/c], and abacavir/lamivudine/dolutegravir [ABC/3TC/DTG]) for more than 2 years at three university-affiliated hospitals in South Korea from May 2014 to December 2020. Analysis was performed in the treatment-naïve and treatment-experienced groups, respectively.

Results

Individual INSTI-based STRs were associated with weight gain at the 24-month follow up in both treatment-naïve (n = 179) and treatment-experienced (n = 290) groups. Body mass index (BMI) categories changed over time for TAF/F/EVG/c and ABC/3TC/DTG, with significant increases in the rates of overweight and obesity in treatment-naïve patients, whereas there was no change for TDF/F/EVG/c. TAF/F/EVG/c significantly increased total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), and triglyceride (TG) compared to other regimens over 24 months. In the treatment-naïve group, a baseline CD4⁺ T cell count <100 cells/mm³, human immunodeficiency virus (HIV) viral load (VL) ≥100,000 copies/mL, no physical exercise, and TAF/F/EVG/c (vs. TDF/F/EVF/c) were risk factors for ≥10% weight gain. In the treatment-experienced group, age <45 years, BMI <25 kg/m², and no physical exercise were risk factors for ≥5% weight gain.

Conclusion

INSTI-based STR continued to increase body weight at the 24-month follow up in treated and untreated Korean PLWH. Exercise, together with demographic-, HIV-, and anti-retroviral therapy-related factors, influenced weight gain. Therefore, when prescribing an INSTI-based STR, weight gain and metabolic changes should be closely monitored in PLWH with these risk factors.

Dolutegravir-Based Dual Therapies in HIV Pretreated Patients: A Real-Life Study in Madrid

BACKGROUND

Few studies describe the use of dolutegravir (DTG)-based dual therapies under routine clinical practice.

OBJECTIVES

To report real-life data on the use of DTG-based dual therapies in treatment-experienced patients.

METHODS

This was an observational, retrospective study. It included all treatment-experienced HIV patients starting a DTG-based dual therapy from 2014 to 2018. The primary end point was to identify the incidence and reasons for the switch. The secondary end points were to assess the effectiveness, safety, adherence, and costs after 48 weeks of treatment (W48).

RESULTS

The incidence of the switch to a DTG-based dual therapy increased from 1.6 patients per 1000 patient-years in 2014 to 38.6 in 2018. A total of 241 patients initiated this therapy: 113 (46.9%) patients started DTG plus rilpivirine (RPV), 72 (29.9%), DTG plus lamivudine (3TC), and 68 (28.2%), DTG plus boosted-darunavir (b-DRV). A total of 170 patients completed W48 of follow-up. By intention-to-treat analysis, 89.3% of virologically suppressed (VS) patients (94.3% with DTG plus b-DRV, 91.3% with DTG plus 3TC, and 87.2% with DTG plus RPV) and 56.7% of non-VS patients (71.4% with DTG plus RPV and 52.2% with DTG plus b-DRV) achieved a viral load <50 copies/mL at W48. The protocol-defined virological failure was 6.5%. Overall, 8.8% of patients had early discontinuation. The annual cost increased by €800 per patient ($916).

CONCLUSIONS AND RELEVANCE

The use of DTG-based dual therapies has increased in real life, showing a favorable effectiveness and safety profile. Treatment costs increased, except for the switch to DTG plus 3TC.

Measurement of total and unbound bictegravir concentrations in plasma and cerebrospinal fluid by UHPLC-MS/MS

Bictegravir is a novel integrase strand transfer inhibitor, administrated in co-formulation with tenofovir alafenamide and emtricitabine (Biktarvy®), indicated in the management of HIV-1 infection in patients not previously treated with antiretroviral therapy. Bictegravir is highly bound to plasma proteins, and this significantly determines its clearance, solubility, and activity. These characteristics are crucial determinants of bictegravir penetration into human body compartments, as the central nervous system. We developed and validated UHPLC-MS/MS procedures to measure total and unbound bictegravir concentrations in plasma and cerebrospinal fluid. Simple protein precipitation with acetonitrile was implemented to prepare plasma and cerebrospinal fluid samples. Sample preparation was preceded by ultrafiltration for measuring unbound bictegravir concentrations. Chromatographic separations were achieved on an Acquity® UHPLC® BEH^TM (2.1 × 100 mm id, 1.7 μm) reverse-phase C₁₈ column using an isocratic mobile phase 20:80 (v/v) water/acetonitrile with 0.1% formic. Bictegravir and its internal standard (bictegravir-¹⁵N d₂) were detected by electrospray ionization mass spectrometry in positive and multiple reaction monitoring modes, using transitions of 450.2→289.2/145.4 and 453.2→289.2, respectively. Ultrafiltration procedures presented non-specific bindings of (8.6 ± 1.2) % for bictegravir in plasma and (26.6 ± 3.1) % for bictegravir in cerebrospinal fluid. Linearity was observed between (10.70-8560) μg/L, (1.07-856.0) μg/L for total and unbound bictegravir in plasma, and 0.107-26.75 μg/L for total and unbound bictegravir in cerebrospinal fluid. Imprecisions, absolute relative biases, normalized-matrix factors, and normalized-recoveries were ≤14.4%, ≤13.8%, (97.4-102.5) %, and (99.8-105.1) %, respectively. No significant interferences and carry-over were observed. The validated UHPLC-MS/MS procedures could be useful for pharmacokinetic and pharmacodynamic studies.