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Aims: The purpose of this study was to assess the antiviral activity of the rilpivirine/emtricitabine/tenofovir disoproxil fumarate combination and to describe the pharmacokinetics of rilpivirine and its association with resistance in clinical routine., Methods: A retrospective multicentre cohort study was performed in both naive and pretreated HIV patients receiving the once-daily rilpivirine/emtricitabine/tenofovir disoproxil fumarate regimen. Immuno-virologic and resistance data, and rilpivirine plasma trough concentrations were collected over the follow-up. Statistical analyses were performed to evaluate the relationship between rilpivirine pharmacokinetics and virological response. Receiver operating characteristic (ROC) curve analysis was performed to determine the best target rilpivirine trough concentration., Results: Overall, 379 patients were included. After a median follow-up of 28 months, 26% of patients discontinued mainly due to toxicity and the virological success rate was 65.7%. Virological failure occurred in 5% of patients. A significant proportion of patients with HIV-RNA > 40 copies/mL displayed rilpivirine plasma trough concentrations below the currently used 50 ng/mL efficacy threshold at both M6 (28%) and M12 (31%), in agreement with a significant lower median rilpivirine plasma trough concentration compared with patients virologically suppressed. Half of the patients with virologic failure who acquired rilpivirine resistance mutations had at least one suboptimal rilpivirine trough concentration. The optimal target for rilpivirine trough concentration was 70 ng/mL (sensitivity 75.4%; specificity 61.5%)., Conclusions: This study shows the impact of rilpivirine plasma trough concentration on both virological response and the emergence of rilpivirine mutations. Moreover, our results suggest that a higher target of rilpivirine trough concentration could be proposed in clinical practice., (© 2020 The British Pharmacological Society.)

Background: Rilpivirine is widely prescribed in people living with HIV. Although trough plasma concentrations have been associated with virological response, the drug pharmacodynamics remain incompletely characterized., Objectives: To develop the first pharmacodynamic model of rilpivirine in order to establish the rilpivirine concentration-response relationship for future treatment optimization., Methods: A retrospective observational study was conducted in patients receiving the once-daily rilpivirine/tenofovir disoproxil fumarate/emtricitabine regimen. Individual rilpivirine trough plasma concentrations over time were predicted using a previous pharmacokinetic model. An established susceptible, infected, recovered model was used to describe HIV dynamics without assuming disease steady-state. Population analysis was performed with MONOLIX 2018 software. Simulations of the viral load evolution as a function of time and rilpivirine trough plasma concentration were performed., Results: Overall, 60 naive and 39 pre-treated patients were included with a follow-up ranging from 2 to 37 months. The final model adequately described the data and the pharmacodynamic parameters were estimated with a good precision. The population typical value of rilpivirine EC50 was estimated at 65 ng/mL. A higher infection rate constant of CD4 cells for HIV-1 was obtained in pre-treated patients. Consequently, the time to obtain virological suppression was longer in pre-treated than in naive patients., Conclusions: The concentration-response relationship of rilpivirine was satisfactorily described for the first time using an original population pharmacodynamic model. Simulations performed using the final model showed that the currently used 50 ng/mL rilpivirine trough plasma concentration efficacy target might need revision upwards, particularly in pre-treated patients., (© The Author(s) 2019. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Background: Risk factors for progressive multifocal leukoencephalopathy (PML) in individuals with human immunodeficiency virus (HIV) infection are poorly documented in the era of combination antiretroviral therapy (cART)., Methods: We studied HIV-1-infected individuals aged ≥15 years who had no history of PML and were prospectively followed up between 1997 and 2011 in the French Hospital Database on HIV (FHDH-ANRS CO4) cohort. Cox models were used to calculate adjusted hazard ratios (HRs), focusing on sub-Saharan origin, suggested to be protective, and recent cART initiation, potentially associated with an increased risk of PML., Results: PML developed in 555 individuals, in 57 during the first 6 months of cART. From 1997-2000 to 2009-2011, the incidence fell from 1.15 (95% confidence interval [CI], .98-1.31) to 0.49 (.37-.61) per 1000 person-years. Sub-Saharan African origin had no clear influence (HR, 0.80; 95% CI, .58-1.11). Compared with men who have sex with men, injection drug users (IDUs) were at higher risk (HR, 1.80 [95% CI, 1.32-2.45] for male and 1.68 [1.13-2.48] for female IDUs). When IDUs were excluded, hepatitis C virus seropositivity was associated with an increased risk (HR, 1.40; 95% CI, 1.02-1.93). Compared with no cART initiation, initiation <6 months previously was associated with PML onset (HR, 4.91; 95% CI, 2.42-9.95)., Conclusions: Recent cART initiation is associated with an increased risk of PML, as are injection drug use and hepatitis C virus seropositivity. Sub-Saharan African origin had no protective effect.

Purpose: Rilpivirine, prescribed for the treatment of HIV infection, presents an important inter-individual pharmacokinetic variability. We aimed to determine population pharmacokinetic parameters of rilpivirine in adult HIV-infected patients and quantify their inter-individual variability., Methods: We conducted a multicenter, retrospective, and observational study in patients treated with the once-daily rilpivirine/tenofovir disoproxil fumarate/emtricitabine regimen. As part of routine therapeutic drug monitoring, rilpivirine concentrations were measured by UPLC-MS/MS. Population pharmacokinetic analysis was performed using NONMEM software. Once the compartmental and random effects models were selected, covariates were tested to explain the inter-individual variability in pharmacokinetic parameters. The final model qualification was performed by both statistical and graphical methods., Results: We included 379 patients, resulting in the analysis of 779 rilpivirine plasma concentrations. Of the observed trough individual plasma concentrations, 24.4% were below the 50 ng/ml minimal effective concentration. A one-compartment model with first-order absorption best described the data. The estimated fixed effect for plasma apparent clearance and distribution volume were 9 L/h and 321 L, respectively, resulting in a half-life of 25.2 h. The common inter-individual variability for both parameters was 34.1% at both the first and the second occasions. The inter-individual variability of clearance was 30.3%., Conclusions: Our results showed a terminal half-life lower than reported and a high proportion of patients with suboptimal rilpivirine concentrations, which highlights the interest of using therapeutic drug monitoring in clinical practice. The population analysis performed with data from "real-life" conditions resulted in reliable post hoc estimates of pharmacokinetic parameters, suitable for individualization of dosing regimen.

Introduction: We compared the effectiveness of tenofovir/emtricitabine (TDF/FTC) combined with either lopinavir/r (LPV/r) or another recommended third drug in the 2010 French guidelines in antiretroviral-naïve patients starting combination antiretroviral therapy in 2004-2008 in the French Hospital Database on HIV., Methods: The outcomes were stop or switch of the third component, viral load (VL) <500 copies/ml, an increase of at least 100 CD4 cells/mm(3), AIDS-defining event and non-AIDS-defining hospitalization or death. Propensity scores were estimated by logistic regression based on the clinical centre and other confounders. In each clinical centre, each patient initiating LPV/r was matched with a patient initiating another third drug (efavirenz or atazanavir/r) and having a close propensity score. Cox's proportional hazards models were then used, with treatment as covariate. Time was right-censored at four years., Results: 1269 patients started LPV/r plus TDF/FTC, and 890 could be matched to 890 patients receiving another third drug. Baseline characteristics were well balanced between these two groups. LPV/r was associated with a higher risk of third drug stop (hazard ratio (HR): 1.69; 95% confidence interval (CI), 1.42-2.00) and with less rapid viral suppression (HR: 0.83; 95% CI, 0.72-0.95). There was no difference in the time required for a CD4 cell increment of at least 100/mm(3), or to the occurrence of an AIDS-defining event. Non-AIDS-defining hospitalizations or deaths were more frequent with LPV/r (HR: 1.79; 95% CI, 1.33-2.39)., Conclusions: For first-line therapy, in this observational setting, TDF/FTC plus LPV/r were less durable than TDF/FTC plus another recommended third drug, led to a less rapid viral suppression and were associated with a higher risk of non-AIDS morbidity.

The aim of this study was to determine the population pharmacokinetic (PK) parameters of atazanavir in adult human immunodeficiency virus-infected patients to build up a Bayesian strategy for dosage regimen individualization. This was an observational study of patients treated with the once-daily regimen atazanavir associated with 100 mg of ritonavir. Blood samples were drawn at steady state at various times ranging from 1 to 26 hours postdose. Atazanavir plasma concentrations were determined by a validated reverse-phase high-performance liquid chromatography method. PK analysis of the atazanavir population was performed using a nonlinear mixed-effects model (NONMEM version 6). One hundred eighty-seven patients were included in the study. The atazanavir doses prescribed were 300 mg (n = 169), 400 mg (n = 12), 200 mg (n = 1), and 150 mg (n = 5). The atazanavir population PK was described using a 1-compartment model with first-order absorption. Mean PK parameter estimations (95% confidence interval, coefficients of variation %) were as follows: oral clearance (CL) = 7.6 L/h (6.9-8.3; 34%), volume of distribution (V) = 80.8 L (67.4-94; 37%), and absorption constant rate (Ka) = 1.05 hours (0.01-2.09; 156%). The mean estimated half-life (T-half) was 7.5 hours (95% confidence interval: 7.2 -7.8 hours). The estimated T-half of atazanavir was in agreement with that previously reported of 8.6 and 8.8 hours. We observed a wide interpatient variability for the PK parameters, especially for Ka. This population approach allowed us to determine atazanavir PK parameters in human immunodeficiency virus-infected patients in a real-life context and to perform Bayesian analysis to predict Ctrough from samples collected at any moment during the dosing interval. This could therefore improve therapeutic drug monitoring interpretations and provide an interesting tool for correlation with virologic data.