Therapeutic monitoring and variability of atazanavir in HIV-infected patients, with and without HCV coinfection, receiving boosted or unboosted regimens

Semi-quantification and Potency Verification of the HIV Protease Inhibitor Based on the Matrix-Capsid Protein Immobilized Nickel (II)/NTA-Tol/Graphene Oxide/SPCE Electrochemical Biosensor

Human immunodeficiency virus (HIV) causing acquired immune deficiency syndrome (AIDS) is still a global issue. Long-term drug treatment and nonadherence to medication increase the spread of drug-resistant HIV strains. Therefore, the identification of new lead compounds is being investigated and is highly desirable. Nevertheless, a process generally necessitates a significant budget and human resources. In this study, a simple biosensor platform for semi-quantification and verification of the potency of HIV protease inhibitors (PIs) based on electrochemically detecting the cleavage activity of the HIV-1 subtype C-PR (C-SA HIV-1 PR) was proposed. An electrochemical biosensor was fabricated by immobilizing His6-matrix-capsid (H₆MA-CA) on the electrode surface via the chelation to Ni²⁺-nitrilotriacetic acid (NTA) functionalized GO. The functional groups and the characteristics of modified screen-printed carbon electrodes (SPCE) were characterized by Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDS). C-SA HIV-1 PR activity and the effect of PIs were validated by recording changes in electrical current signals of the ferri/ferrocyanide redox probe. The detection of PIs, i.e., lopinavir (LPV) and indinavir (IDV), toward the HIV protease was confirmed by the decrease in the current signals in a dose-dependent manner. In addition, our developed biosensor demonstrates the ability to distinguish the potency of two PIs to inhibit C-SA HIV-1 PR activities. We anticipated that this low-cost electrochemical biosensor would increase the efficiency of the lead compound screening process and accelerate the discovery and development of new HIV drugs.

No difference in effectiveness of treatment simplification to boosted or unboosted atazanavir plus lamivudine in virologically suppressed in HIV-1-infected patients

Background

Simplification strategies of antiretroviral treatment represent effective tools for the reduction of drug-induced toxicity, resistance mutations in case of virological failure and costs.

Objectives

To assess the effectiveness of simplification to atazanavir/ritonavir (ATV_rtv) or unboosted atazanavir (ATV₄₀₀) plus lamivudine, and if low plasma or intracellular ATV C_trough influence virological outcomes.

Methods

Ambispective observational study in patients with undetectable HIV-RNA who were switched to ATV_rtv or ATV₄₀₀ plus lamivudine once daily. Previous virological failures (VF) were allowed if the resistance tests showed major resistance mutation neither to ATV nor to lamivudine. VF was defined as two consecutive plasma HIV-RNA >200 copies/mL. Effectiveness was assessed by intention-to-treat and on-treatment analyses. Plasma and intracellular ATV C_trough were measured by LC-MS/MS.

Result

A total of 246 patients were included. At week 48, the Kaplan–Meier estimation of efficacy within the ATV_rtv and ATV₄₀₀ groups were 85.9% [95% confidence interval, (CI₉₅), 80.3–91.4%] versus 87.6% (CI₉₅, 80.1–94.1%) by intention-to-treat analysis (p = 0.684), and 97.7% (CI₉₅, 95.2–100%) versus 98.8% (CI₉₅, 97.0–100%) by on-treatment analysis (p = 0.546), respectively. Plasma and intracellular C_trough were significantly higher with ATV_rtv than with ATV₄₀₀ (geometric mean (GM), 318.3 vs. 605.9 ng/mL; p = 0.013) and (811.3 vs. 2659.2 ng/mL; p = 0.001), respectively. Only 14 patients had plasma C_trough below the suggested effective concentration for ATV (150 ng/mL). No relationship between plasma or intracellular C_trough and VF or blips were found.

Conclusion

Boosted or unboosted ATV plus lamivudine is effective and safe, and the lower plasma C_trough observed with ATV₄₀₀ do not compromise the effectiveness of these simplification regimens in long-term virologically suppressed HIV-1-infected patients.

Fosamprenavir/ritonavir in patients with viral hepatitis coinfection: an observational multicohort study

OBJECTIVE

Safety and tolerability evaluation of adapted dose regimens containing fosamprenavir/ritonavir (FPV/r) in HIV-infected subjects with viral hepatitis co-infection.

METHODS

A retrospective multicohort analysis was conducted. Subjects from three European cohorts who started FPV/r or lopinavir/ritonavir (LPV/r) as a comparator contributed data to a centralized database. Subjects were divided into five groups by treatment regimen and level of hepatic impairment (aspartate aminotransferase [AST] platelet ratio index [APRI] score < or ≥2). Multivariable Cox regression analyses controlling for demographic factors, baseline CD4 count, FIB-4 score, use of antiretroviral therapy, and laboratory markers (bilirubin and platelet count) were performed to identify factors independently associated with risk of developing adverse events or safety events (eg, drug discontinuation, alanine aminotransferase (ALT) elevation, hepatic decompensation/death).

RESULTS

A total of 1096 patients contributed data to the study. Fosamprenavir/ritonavir (except in subjects with APRI ≥2 receiving standard dose) was associated with a higher two-year risk of drug discontinuation compared with LPV/r. Restricting the analysis to discontinuations due to adverse events (AEs), only subjects who received the reduced dose were more likely to discontinue ≥1 drug in the FPV/r regimen. There were no statistical differences in ALT elevation between groups. Incidence of hepatic decompensation events was similar among groups except for subjects who received non standard doses of FPV, though the number of events was small.

CONCLUSIONS

Fosamprenavir/ritonavir discontinuation rate due to AEs or ALT elevation was similar across all European-approved FPV/r doses and to that of LPV/r subjects.  Although liver tolerated antiretrovirals, such as integrase inhibitor and entry inhibitor, the use of FPV/r is acceptable in HIV infected patients with viral hepatitis.

Liver Toxicity of Current Antiretroviral Regimens in HIV-Infected Patients with Chronic Viral Hepatitis in a Real-Life Setting: The HEPAVIR SEG-HEP Cohort

OBJECTIVE

To assess the current frequency of ART-associated grade 3-4 transaminase elevations (TE) and grade 4 total bilirubin elevations (TBE) in HIV-infected patients with chronic hepatitis B and/or C, who start a new regimen of ART.

PATIENTS AND METHODS

A total of 192 pre-treated or treatment-naive HIV infected patients with HBV and/or HCV-coinfection who started ART in eight Southern Spanish centers from July/2011-December/2013, were followed for 12 months in this prospective study.

RESULTS

Forty-one (21.4%) subjects had been naïve to ART, median (IQR) follow-up was 11.6 (5.6-12.9) months. The most frequently initiated NRTI were tenofovir/emtricitabine [49 patients (25.5%)]. Eighty-nine (46.4%) patients started a ritonavir-boosted protease inhibitor and 77 (40.1%) individuals a NNRTI. Raltegravir and maraviroc were initiated in 24 (12.5%) and 9 (4.7%) individuals. Ten [5.21%; 95% confidence interval (CI): 2.53%-9.37%] patients presented grade 3 TE, while 8 (4.17%; 95%CI: 1.82%-8.04%) subjects showed grade 4 TBE. No episodes of grade 4 TE or ART discontinuation due to hepatotoxic events were observed. The use of ritonavir-boosted atazanavir was the only independent predictor for grade 4 TBE [adjusted odds ratio: 7.327 (95%CI: 1.417-37.89); p = 0.018] in an analysis adjusted for age, sex and baseline HIV-RNA levels, while no factor could be independently associated with grade 3-4 TE.

CONCLUSIONS

Currently, the frequency of severe ART-associated TE and TBE under real-life conditions in patients with chronic viral hepatitis is similar to what has been reported previously. However, episodes of grade 4 TE are less frequent and severe TE appears to be of lesser concern.

Evaluation of high sensitive troponin in erectile dysfunction

Background. Evidence is accumulating in favour of a link between erectile dysfunction (ED) and coronary artery diseases. We investigated the presence of cardiac injury in patients who have had arteriogenic and nonarteriogenic ED using the hs-Tn levels. Methods. The diagnosis of ED was based on the International Index of Erectile Function 5-questionnaire (IIF-5) and patients were classified as arteriogenic (A-ED, n = 40), nonarteriogenic (NA-ED, n = 48), and borderline (BL-ED, n = 32) patients in relation to the results of echo-color-Doppler examination of cavernous arteries. The level of hs-TnT and hs-TnI was measured in 120 men with a history of ED of less than one year with no clinical evidence of cardiac ischemic disease. Results. The levels of both hs-TnT and hs-TnI were within the reference range and there was no significant (P > 0.05) difference between patients of the three groups. The hs-CRP values were higher in A-ED men compared with NA-ED (P = 0.048) but not compared with BL-ED (P = 0.136) and negatively correlated with IIF-5 (r = −0.480; P = 0.031). Conclusions. In ED patients of the three groups the measurement of hs-Tn allows us to exclude the presence of cardiac involvement at least when the history of ED is less than one year and the men are without atherosclerotic risk factors.

Plasma concentrations of efavirenz, darunavir/ritonavir and raltegravir in HIV-HCV-coinfected patients without liver cirrhosis in comparison with HIV-monoinfected patients

BACKGROUND

The objective of the study was to assess plasma concentrations of efavirenz, darunavir/ritonavir and raltegravir in patients with human immunodeficiency virus-hepatitis C virus (HIV-HCV)-coinfection without liver cirrhosis.

METHODS

In this observational, open-label study, adult HIV-infected outpatients treated with tenofovir/emtricitabine plus efavirenz (600 mg daily), darunavir/ritonavir (800/100 mg daily) or raltegravir (400 mg twice daily) for at least 4 weeks were asked to participate. Subjects with liver cirrhosis were excluded. The trough concentration (C trough) of darunavir/ritonavir and raltegravir and the mid-dose concentration (C12h) of efavirenz were assessed at steady state by a validated high-performance liquid chromatography (HPLC)-tandem mass spectrometry method.

RESULTS

A total of 96 HIV-positive patients were enrolled into the study. Thirty-four patients were treated with efavirenz, 33 with darunavir/ritonavir and 29 with raltegravir. The geometric mean plasma C trough [coefficient of variation (%)] of darunavir was comparable between HIV+/HCV+ and HIV+/HCV- subjects: 2644 ng/ml (155%) and 2491 ng/ml (139%), respectively (geometric mean ratio (GMR) = 0.81; 95% confidence interval (CI) = 0.79-1.56; p = 0.69). These values were comparable for raltegravir: 108 ng/ml (149%) in the HIV+/HCV+ group and 96 ng/ml (161%) in the HIV+/HCV- group (GMR = 0.84; 95% CI = 0.61-1.44; p = 0.72). On the contrary, the geometric mean plasma C12h of efavirenz was significantly higher among the 15 HIV+/HCV+ patients (1915 ng/ml, 159%) than among the 19 HIV+/HCV- patients (1505 ng/ml, 167%; GMR = 1.41; 95% CI = 1.19-1.71; p = 0.009).

CONCLUSIONS

The mean plasma concentration of efavirenz was significantly higher in HCV-positive than in HCV-negative patients without liver cirrhosis, while the mean plasma levels of darunavir/ritonavir and raltegravir were comparable in both groups.

[Consensus Statement by GeSIDA/National AIDS Plan Secretariat on antiretroviral treatment in adults infected by the human immunodeficiency virus (Updated January 2013)]

OBJECTIVE

This consensus document is an update of combined antiretroviral therapy (cART) guidelines for HIV-1 infected adult patients.

METHODS

To formulate these recommendations a panel composed of members of the GeSIDA/National AIDS Plan Secretariat (Grupo de Estudio de Sida and the Secretaría del Plan Nacional sobre el Sida) reviewed the efficacy and safety advances in clinical trials, cohort and pharmacokinetic studies published in medical journals (PubMed and Embase) or presented in medical scientific meetings. The strength of the recommendations and the evidence which support them are based on a modification of the criteria of Infectious Diseases Society of America.

RESULTS

cART is recommended in patients with symptoms of HIV infection, in pregnant women, in serodiscordant couples with high risk of transmission, in hepatitisB co-infection requiring treatment, and in HIV nephropathy. cART is recommended in asymptomatic patients if CD4 is <500cells/μl. If CD4 are >500cells/μl cART should be considered in the case of chronic hepatitisC, cirrhosis, high cardiovascular risk, plasma viral load >100.000 copies/ml, proportion of CD4 cells <14%, neurocognitive deficits, and in people aged >55years. The objective of cART is to achieve an undetectable viral load. The first cART should include 2 reverse transcriptase inhibitors (RTI) nucleoside analogs and a third drug (a non-analog RTI, a ritonavir boosted protease inhibitor, or an integrase inhibitor). The panel has consensually selected some drug combinations, for the first cART and specific criteria for cART in acute HIV infection, in tuberculosis and other HIV related opportunistic infections, for the women and in pregnancy, in hepatitisB or C co-infection, in HIV-2 infection, and in post-exposure prophylaxis.

CONCLUSIONS

These new guidelines update previous recommendations related to first cART (when to begin and what drugs should be used), how to monitor, and what to do in case of viral failure or adverse drug reactions. cART specific criteria in comorbid patients and special situations are similarly updated.

CD4 cell count and viral load-specific rates of AIDS, non-AIDS and deaths according to current antiretroviral use

BACKGROUND

CD4 cell count and viral loads are used in clinical trials as surrogate endpoints for assessing efficacy of newly available antiretrovirals. If antiretrovirals act through other pathways or increase the risk of disease this would not be identified prior to licensing. The aim of this study was to investigate the CD4 cell count and viral load-specific rates of fatal and nonfatal AIDS and non-AIDS events according to current antiretrovirals.

METHODS

Poisson regression was used to compare overall events (fatal or nonfatal AIDS, non-AIDS or death), AIDS events (fatal and nonfatal) or non-AIDS events (fatal or nonfatal) for specific nucleoside pairs and third drugs used with more than 1000 person-years of follow-up (PYFU) after 1 January 2001.

RESULTS

Nine thousand, eight hundred and one patients contributed 42372.5 PYFU, during which 1203 (437 AIDS and 766 non-AIDS) events occurred. After adjustment, there was weak evidence of a difference in the overall events rates between nucleoside pairs (global P-value = 0.084), and third drugs (global P-value = 0.031). As compared to zidovudine/lamivudine, patients taking abacavir/lamivudine [adjusted incidence rate ratio (aIRR) 1.22; 95% CI 0.99-1.49] and abacavir and one other nucleoside [aIRR 1.51; 95% CI 1.14-2.02] had an increased incidence of overall events. Comparing the third drugs, those taking unboosted atazanavir had an increased incidence of overall events compared with those taking efavirenz (aIRR 1.46; 95% CI 1.09-1.95).

CONCLUSION

There was little evidence of substantial differences between antiretrovirals in the incidence of clinical disease for a given CD4 cell count or viral load, suggesting there are unlikely to be major unidentified adverse effects of specific antiretrovirals.

Unboosted atazanavir for treatment of HIV infection: rationale and recommendations for use

Atazanavir (Reyataz®) is a protease inhibitor (PI) for the treatment of HIV infection. Several trials have demonstrated the good efficacy and toxicity profile of atazanavir boosted by ritonavir (atazanavir/r). However, several toxicity events and pharmacokinetic issues due to drug-to-drug interactions (partly related to ritonavir) may complicate atazanavir/r therapy. This is why regimens with unboosted atazanavir have been experimented with and are used in clinical practice. The aim of this article is to identify the clinical settings in which unboosted atazanavir may be a safe and effective option for the long-term control of HIV replication. Despite the fact that a favourable lipid profile and good gastrointestinal tolerability have been reported in comparative trials, unboosted atazanavir should not be considered an optimal choice for treatment-naive patients. In fact, boosting with ritonavir produces higher atazanavir plasma levels, which are beneficial in terms of efficacy, especially in untreated patients with high plasma HIV RNA. Clinical data indicate that, in patients with sustained undetectable HIV RNA and without previous virological failure or HIV drug resistance-associated mutations, a switch to unboosted atazanavir-based regimens is a feasible option to control and prevent toxicity events, especially in patients who cannot tolerate ritonavir and in those with severe hyperbilirubinaemia on atazanavir/r. Moreover, while unboosted atazanavir must not be used in pregnant women, it is a recommended option in special populations, such as patients with moderate liver insufficiency. Lastly, unboosted atazanavir in combination with raltegravir may allow the construction of a well tolerated and effective regimen without nucleoside reverse transcriptase inhibitors in patients for whom these drugs are contraindicated. In conclusion, there is a good rationale, significant clinical interest and accumulating clinical experience with unboosted atazanavir-based regimens, although this formulation should be used only in specific situations and as a maintenance strategy. Moreover, therapeutic drug monitoring could be useful in specific circumstances (such as in patients with liver impairment or in case of potential drug-drug interactions).

[Consensus document of Gesida and Spanish Secretariat for the National Plan on AIDS (SPNS) regarding combined antiretroviral treatment in adults infected by the human immunodeficiency virus (January 2012)]

This consensus document has been prepared by a panel consisting of members of the AIDS Study Group (Gesida) and the Spanish Secretariat for the National Plan on AIDS (SPNS) after reviewing the efficacy and safety results of clinical trials, cohort and pharmacokinetic studies published in medical journals, or presented in medical scientific meetings. Gesida has prepared an objective and structured method to prioritise combined antiretroviral treatment (cART) in naïve patients. Recommendations strength (A, B, C) and the evidence which supports them (I, II, III) are based on a modification of the Infectious Diseases Society of America criteria. The current antiretroviral treatment (ART) of choice for chronic HIV infection is the combination of three drugs. ART is recommended in patients with symptomatic HIV infection, in pregnancy, in serodiscordant couples with high transmission risk, hepatitis B fulfilling treatment criteria, and HIV nephropathy. Guidelines on ART treatment in patients with concurrent diagnosis of HIV infection and an opportunistic type C infection are included. In asymptomatic patients ART is recommended on the basis of CD4 lymphocyte counts, plasma viral load and patient co-morbidities, as follows: 1) therapy should be started in patients with CD4 counts <350 cells/μL; 2) when CD4 counts are between 350 and 500 cells/μL, therapy will be recommended and only delayed if patient is reluctant to take it, the CD4 are stabilised, and the plasma viral load is low; 3) therapy could be deferred when CD4 counts are above 500 cells/μL, but should be considered in cases of cirrhosis, chronic hepatitis C, high cardiovascular risk, plasma viral load >10(5) copies/mL, proportion of CD4 cells <14%, and in people aged >55 years. ART should include 2 reverse transcriptase inhibitors nucleoside analogues and a third drug (non-analogue reverse transcriptase inhibitor, ritonavir boosted protease inhibitor or integrase inhibitor). The panel has consensually selected and given priority to using the Gesida score for some drug combinations, some of them co-formulated. The objective of ART is to achieve an undetectable viral load. Adherence to therapy plays an essential role in maintaining antiviral response. Therapeutic options are limited after ART failures, but an undetectable viral load may be possible nowadays. Adverse events are a fading problem of ART. Guidelines in acute HIV infection, in women, in pregnancy, and to prevent mother-to-child transmission and pre- and post-exposition prophylaxis are commented upon. Management of hepatitis B or C co-infection, other co-morbidities, and the characteristics of ART in HIV-2 infection are included.