Efficacy and safety of boosted darunavir-based antiretroviral therapy in HIV-1-positive patients: results from a meta-analysis of clinical trials

HIV epidemiology, prevention, treatment, and implementation strategies for public health

The global HIV response has made tremendous progress but is entering a new phase with additional challenges. Scientific innovations have led to multiple safe, effective, and durable options for treatment and prevention, and long-acting formulations for 2-monthly and 6-monthly dosing are becoming available with even longer dosing intervals possible on the horizon. The scientific agenda for HIV cure and remission strategies is moving forward but faces uncertain thresholds for success and acceptability. Nonetheless, innovations in prevention and treatment have often failed to reach large segments of the global population (eg, key and marginalised populations), and these major disparities in access and uptake at multiple levels have caused progress to fall short of their potential to affect public health. Moving forward, sharper epidemiologic tools based on longitudinal, person-centred data are needed to more accurately characterise remaining gaps and guide continued progress against the HIV epidemic. We should also increase prioritisation of strategies that address socio-behavioural challenges and can lead to effective and equitable implementation of existing interventions with high levels of quality that better match individual needs. We review HIV epidemiologic trends; advances in HIV prevention, treatment, and care delivery; and discuss emerging challenges for ending the HIV epidemic over the next decade that are relevant for general practitioners and others involved in HIV care.

Cardiovascular risks associated with protease inhibitors for the treatment of HIV

Introduction: Cumulative use of some first-generation protease inhibitors has been associated with higher rates of dyslipidemia and increased risk of cardiovascular disease. The protease inhibitors most commonly in use are atazanavir and darunavir, which have fewer detrimental lipid effects and greater tolerability. This paper aims to review the evidence of a potential association of these contemporary protease inhibitors with the risk of ischemic CVD and atherosclerotic markers.Areas covered: We searched for publications of randomized trials and observational studies on PubMed from 1 January 2000 onwards, using search terms including: protease inhibitors; darunavir; atazanavir; cardiovascular disease; cardiovascular events; dyslipidemia; mortality; carotid intima media thickness; arterial elasticity; arterial stiffness and drug discontinuation. Ongoing studies registered on clinicaltrials.gov as well as conference abstracts from major HIV conferences from 2015-2020 were also searched.Expert opinion: Atazanavir and darunavir are no longer part of first-line HIV treatment, but continue to be recommended as alternative first line, second- and third-line regimens, as part of two drug regimens, and darunavir is used as salvage therapy. Although these drugs will likely remain in use globally for several years to come, baseline CVD risk should be considered when considering their use, especially as the population with HIV ages.

Cost-effectiveness and budget impact of dolutegravir/lamivudine for treatment of human immunodeficiency virus (HIV-1) infection in the United States

BACKGROUND: Dolutegravir(DTG)/lamivudine(3TC) is the first 2-drug regimen recommended as an initial treatment for people living with HIV (PLHIV). OBJECTIVE: To assess the cost-effectiveness and potential budget impact of DTG/3TC in the US healthcare setting. METHODS: A previously published hybrid decision-tree and Markov cohort state transition model was adapted to estimate the incremental costs and health outcome benefits over a patients' lifetime. DTG/3TC was compared with current standard of care in treatment naive and treatment experienced virologically suppressed PLHIV. Health states included in the model were based upon virologic response and CD4 cell count, with death as an absorbing state. Clinical data was informed by the Phase III GEMINI 1 and 2 clinical trials, a published network meta-analysis (NMA) in treatment-naive patients and the Phase III TANGO clinical trial in treatment experienced patients. Costs and utilities were informed by published data and discounted annually at a rate of 3%. A separate 5-year budget impact analysis was conducted assuming 5%-15% uptake in eligible treatment naive and 10%-30% uptake in eligible treatment experienced patients. RESULTS: In the treatment naive analyses based on GEMINI 1 and 2, DTG/3TC dominated, i.e., was less costly and more effective, than all comparators. DTG/3TC resulted in 0.083 incremental quality-adjusted life-years (QALYs) at a cost saving of $199,166 compared with the DTG + tenofovir disoproxil(TDF)/emtricitabine(FTC) comparator arm. The incremental QALY and cost savings for DTG/3TC compared with DTG/abacavir(ABC)/3TC, cobicistat-boosted darunavir(DRV/c)/tenofovir alafenamide(TAF)/FTC, and bictegravir (BIC)/TAF/FTC, based on NMA results were 0.465, 0.142, and 0.698, and $42,948, $122,846, and $44,962, respectively. In the analyses of treatment-experienced virologically suppressed patients based on TANGO, DTG/3TC offered slightly lower QALYs (-0.037) with an estimated savings of $78,730 when compared with continuation of TAF-based regimen (TBR). Sensitivity analyses demonstrated that these conclusions were relatively insensitive to alternative parameter estimates. The budget impact analysis estimated that by 5th year a total of 70,240 treatment naive patients and 1,340,480 treatment experienced patients could be eligible to be prescribed DTG/3TC. The estimated budget savings over 5 years ranged from $1.12b to $3.35b (corresponding to 27,512 to 82,536 on DTG/3TC by year 5) in the lowest and highest uptake scenarios, respectively. CONCLUSION: In conclusion, DTG/3TC with its comparable efficacy and lower drug acquisition costs, has the potential to offer significant cost savings to US healthcare payers for the initial treatment of treatment naive patients and as a treatment switching option for virologically suppressed patients. DISCLOSURES: This study was funded in full by ViiV healthcare, Brentford, UK. Medical writing to support this study was also funded in full by ViiV Healthcare, Brentford, UK. Butler, Hayward, and Jacob are employees of HEOR Ltd, the company performing this study funded by ViiV Healthcare. Anderson is an employee of GlaxoSmithKline and owns shares in the company. Punekar, Evitt, and Oglesby are employees of ViiV Healthcare and own stocks in GlaxoSmithKline.

The potential role of bictegravir/emtricitabine/tenofovir alafenamide (BIC/FTC/TAF) single-tablet regimen in the expanding spectrum of fixed-dose combination therapy for HIV

Single-tablet regimens (STRs) of highly safe and effective combination antiretroviral therapy (cART) have had a significant beneficial impact on the clinical outcomes and lives of people living with HIV (PLHIV). As a consequence, healthcare professionals caring for PLHIV in high-income countries have increasingly focused on issues beyond those related to HIV itself, i.e. HIV-related neurological disease, or associated opportunistic infections, which include co-infections, and primarily age- and lifestyle-related comorbidities such as cardiovascular disease, diabetes mellitus, renal impairment, osteoporosis and frailty. This review considers drug side effects and comorbidities seen in PLHIV and evaluates the role of a recently licensed STR - bictegravir/emtricitabine/tenofovir alafenamide (BIC/FTC/TAF) - in mitigating some of those challenges. Factors that need to be evaluated for initial cART regimens include: pretreatment CD4 cell count; plasma HIV RNA; HIV drug resistance; hepatitis B co-infection; HLA-B*5701 status; drug-drug interactions; pregnancy and pregnancy potential; psychiatric and physical comorbidities such as renal or bone disease, as well as simplicity and adherence-friendliness, all of which need to be considered in all lines of therapy. BIC/FTC/TAF constitutes a new STR that includes an unboosted integrase strand transfer inhibitor with a high barrier against resistance with TAF and FTC. Its virological efficacy was non-inferior to dolutegravir-based regimens previously recommended by most guidelines for treatment initiation in large double-blind, randomised clinical trials in treatment-naïve or switch patients over 96 weeks. Tolerability and pharmacological properties of the regimen make it a useful tool to address several of the clinical management issues raised above.

A Low Level of Darunavir Resistance-Associated Mutation Emergence in Patients With Virological Failure During Long-term Use of Darunavir in People With HIV. The ANRS CO3 Aquitaine Cohort

Background

Ritonavir-boosted darunavir (DRV/r) is a protease inhibitor (PI) indicated for the treatment of naïve and pretreated HIV-infected patients since 2007. Our study aims to describe DRV/r-treated patients experiencing virological failure (VF) documented with HIV resistance testing.

Methods

Data from patients belonging to the ANRS CO3 Aquitaine Cohort treated with a regimen including DRV/r between February 2007 and December 2015 were analyzed. Baseline characteristics of patients experiencing VF (defined by 2 consecutive plasma viral loads >50 copies/mL) were compared with those without VF. We then described factors associated with VF as emergence of IAS DRV resistance–associated mutations (RAMs).

Results

Among the 1458 patients treated at least once with a DRV/r-based regimen, 270 (18.5%) patients experienced VF during follow-up, including 240 with at least 1 genotype resistance test (GRT). DRV RAMs were detected in 29 patients (12%). Among them, 25/29 patients had ≥2 DRV RAMs before DRV/r initiation, all of whom had experienced VF during previous PI treatments. For 18/29, DRV/r was maintained after VF, and controlled viremia was restored after modification of DRV-associated antiretroviral molecules or increased DRV dose. Finally, only 6/29 patients selected new DRV RAMs after DRV/r initiation. All of these experienced previous VFs while on other PIs.

Conclusions

These results highlight the efficacy and robustness of DRV/r, as the emergence of DRV RAMs appeared in <0.4% of patients receiving a DRV/r-based regimen in our large cohort.

Use of darunavir in HIV-1-infected individuals in routine clinical practice from 2012 to 2016 in France

OBJECTIVES

We assessed virological outcomes of darunavir use in France from 2012 to 2016, in three groups of people living with HIV (PLHIV): (i) antiretroviral (ARV)-naive PLHIV; (ii) ARV-experienced PLHIV switching to darunavir while failing therapy; and (iii) ARV-experienced PLHIV switching to darunavir while virologically controlled.

METHODS

Virological success (VS) was defined as a plasma HIV-1 viral load (VL) <50 copies/mL and virological failure (VF) as two consecutive VL >50 copies/mL or one VL >50 copies/mL followed by a treatment switch prior to the next VL measurement. The cumulative incidence of VS was assessed considering darunavir discontinuation, loss to follow-up and death as competing risks, while estimates of cumulative incidence of VF accounted for loss to follow-up and death.

RESULTS

Among the 3235 ARV-naive PLHIV initiating darunavir, the 4 year cumulative incidence of VS was 80.9% and was associated with lower VL and higher CD4 cell counts. Among the 3485 ARV-experienced PLHIV switching to darunavir while failing therapy, the 4 year cumulative incidence of VS was 82.2% and was associated with lower VL. Among the 3005 ARV-experienced PLHIV switching to darunavir while virologically controlled, the 4 year cumulative incidence of VF was 12.6%. The risk of VF was higher with darunavir monotherapy [subdistribution hazard ratio (sHR)=1.67, 95% CI 1.15-2.42] while no difference was observed with dual therapy (sHR = 1.00, 95% CI 0.71-1.42) relative to triple therapy or more.

CONCLUSIONS

Darunavir-containing regimens yielded similarly high rates of viral suppression in PLHIV whether they were ARV naive or ARV experienced switching to darunavir while failing therapy, or of maintaining VS in ARV-experienced PLHIV switching to darunavir while virologically controlled.

High levels of HIV drug resistance among adults failing second-line antiretroviral therapy in Namibia

To support optimal third-line antiretroviral therapy (ART) selection in Namibia, we investigated the prevalence of HIV drug resistance (HIVDR) at time of failure of second-line ART. A cross-sectional study was conducted between August 2016 and February 2017. HIV-infected people ≥15 years of age with confirmed virological failure while receiving ritonavir-boosted protease inhibitor (PI/r)-based second-line ART were identified at 15 high-volume ART clinics representing over >70% of the total population receiving second-line ART. HIVDR genotyping of dried blood spots obtained from these individuals was performed using standard population sequencing methods. The Stanford HIVDR algorithm was used to identify sequences with predicted resistance; genotypic susceptibility scores for potential third-line regimens were calculated. Two hundred thirty-eight individuals were enrolled; 57.6% were female. The median age and duration on PI/r-based ART at time of enrolment were 37 years and 3.46 years, respectively. 97.5% received lopinavir/ritonavir-based regimens. The prevalence of nucleoside reverse transcriptase inhibitor (NRTI), non-nucleoside reverse transcriptase inhibitor (NNRTI), and PI/r resistance was 50.6%, 63.1%, and 13.1%, respectively. No significant association was observed between HIVDR prevalence and age or sex. This study demonstrates high levels of NRTI and NNRTI resistance and moderate levels of PI resistance in people receiving PI/r-based second-line ART in Namibia. Findings underscore the need for objective and inexpensive measures of adherence to identify those in need of intensive adherence counselling, routine viral load monitoring to promptly detect virological failure, and HIVDR genotyping to optimize selection of third-line drugs in Namibia.

Maintenance of virologic suppression and improvement in comorbidities after simplification to raltegravir plus boosted darunavir among treatment-experienced HIV-infected patients

The use of two potent, well-tolerated, drugs could permit the maintenance of virologic suppression even in heavily pretreated people living with HIV. In this retrospective, multicenter, simplification study (NCT03348449), we included those patients with virologic suppression who switched to raltegravir (RAL) plus boosted darunavir (b/DRV). Overall, 345 patients (75 females, 25%) were included. Patients were largely pretreated (mean, 9.4 regimens), suppressed for a median of 41.1 months. Fifty patients had ≥1 mutation against DRV. At 96 weeks, the efficacy by intention-to-treat analysis (snapshot) was 73% (95%CI, 68.4–77.8%), but 97.1% (95%CI, 95.4–98.9) excluding changes due to non-virologic reasons, and virologic failure was rare (0.9%; 95%CI, 0.1–1.2%). Median CD4/CD8 ratio increased from 0.59 to 0.62 (p < 0.01), CD4+ cell count by +90 cells/µl (p < 0.01), and mean estimated glomerular filtration rate (eGFR) increased from 85.2 to 88.5 ml/min at 96 weeks, greater for patients receiving tenofovir disoproxil fumarate (eGFR, +3.6 ml/min, p = 0.04; serum phosphate +0.33 mg/dl; p < 0.01). There was a continued and significant improvement in the total cholesterol/high-density lipoprotein-cholesterol ratio. In conclusion, the simplification to a dual regimen with the combination of RAL and b/DRV is associated with maintenance of virologic suppression, even in largely pretreated patients, with improvements in CD4+ cell count, CD4/CD8 ratio, and in renal and lipid parameters.

Confirmation of the drug-drug interaction potential between cobicistat-boosted antiretroviral regimens and hormonal contraceptives

BACKGROUND

Cobicistat (COBI), a CYP3A inhibitor, is a pharmacokinetic enhancer that increases exposures of the HIV protease inhibitors (PIs) atazanavir (ATV) and darunavir (DRV). The potential drug interaction between COBI-boosted PIs and hormonal contraceptives, which are substrates of intestinal efflux transporters and extensively metabolized by CYP enzymes, glucuronidation and sulfation, was evaluated.

METHODS

This was a Phase I, open-label, two cohort (n=18/cohort), fixed-sequence study in healthy females that evaluated the drug-drug interaction (DDI) between multiple-dose ATV+COBI or DRV+COBI and single-dose drospirenone/ethinyl estradiol (EE). DDIs were evaluated using 90% confidence intervals of the geometric least-squares mean ratios of the test (drospirenone/EE+boosted PI) versus reference (drospirenone/EE) using lack of DDI boundaries of 70-143%. Safety was assessed throughout the study.

RESULTS

29/36 participants completed the study. Relative to drospirenone/EE alone, drospirenone area under the plasma concentration versus time curve extrapolated to infinity (AUC_inf) was 1.6-fold and 2.3-fold higher, and maximum observed plasma concentration (C_max) was unaltered, upon coadministration with DRV+COBI and ATV+COBI, respectively. EE AUC_inf decreased 30% with drospirenone/EE + DRV+COBI and was unchanged with ATV+COBI + drospirenone/EE, relative to drospirenone/EE alone. Study treatments were generally well tolerated. The majority of adverse events were mild and consistent with known safety profiles of the compounds.

CONCLUSIONS

Consistent with COBI-mediated CYP3A inhibition, drospirenone exposure increased following coadministration with COBI-containing regimens, with a greater increase with ATV+COBI. Thus, clinical monitoring for drospirenone-associated hyperkalaemia is recommended with DRV+COBI and ATV+COBI should not be used with drospirenone. Lower EE exposure with DRV+COBI may be attributed to inductive effects of DRV on CYP enzymes and/or intestinal efflux transporters (that is, P-gp) involved in EE disposition.

Darunavir for the treatment of HIV infection

INTRODUCTION

Darunavir (DRV) was the last approved protease inhibitor (PI) and has been extensively used for the treatment of HIV in both naïve and experienced subjects due to its high genetic barrier and efficacy. The introduction in clinical practice of integrase strand transfer inhibitors limited its role in the management of naïve subjects and in antiretroviral treatment simplification strategies. However, recent data from trials that have investigated the new DRV/cobicistat/emtricitabine/tenofovir alafenamide (D/C/F/TAF) combination showed an excellent efficacy and tolerability of this coformulation both in naïve patients and in those with viral suppression, making D/C/F/TAF a new option for the treatment of HIV infection. Areas covered: The authors present and discuss the efficacy and safety data of DRV when used in antiretroviral-naïve, multiexperienced subjects and in the setting of treatment deintensification in subjects with viral suppression. Moreover, the authors evaluate the recent data from two different Phase III trials on D/C/F/TAF both in treatment-naïve and virologically suppressed subjects. Expert opinion: Although novel antiretroviral drugs may become available over time, DRV continues to represent a valuable option for multiexperienced subjects and has a role in simplification regimens. In addition, the convenience of D/C/F/TAF coformulation may be useful for the future management of HIV-infected subjects.