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Leung E, Cottrell ML, Sykes C, White N, Kashuba ADM, Dumond JB. A multicompartment population PK model to predict tenofovir and emtricitabine mucosal tissue concentrations for HIV prevention. CPT Pharmacometrics Syst Pharmacol 2023; 12:1922-1930. [PMID: 37814498 PMCID: PMC10725258 DOI: 10.1002/psp4.13042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Revised: 08/02/2023] [Accepted: 08/28/2023] [Indexed: 10/11/2023] Open
Abstract
A priori use of mathematical modeling and simulation to predict outcomes from incomplete adherence or reduced frequency dosing strategies may mitigate the risk of clinical trial failure with HIV pre-exposure prophylaxis regimens. We developed a semi-physiologic population pharmacokinetic model for two antiretrovirals and their active intracellular metabolites in three mucosal tissues using pharmacokinetic data from a phase I, dose-ranging study. Healthy female volunteers were given a single oral dose of tenofovir disoproxil fumarate (150, 300, or 600 mg) or emtricitabine (100, 200, or 400 mg). Simultaneous co-modeling of all data was performed on a Linux cluster. A 16 compartment, bolus input, linear kinetic model best described the data, containing 986 observations in 23 individuals across three matrices and four analytes. Combined with a defined efficacious concentration target in mucosal tissues, this model can be used to optimize the dose and dosing frequency through Monte-Carlo simulations.
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Affiliation(s)
- Erick Leung
- Division of Pharmacotherapy and Experimental TherapeuticsUniversity of North Carolina UNC Eshelman School of PharmacyChapel HillNorth CarolinaUSA
- Present address:
Certara, Inc.PrincetonNew JerseyUSA
| | - Mackenzie L. Cottrell
- Division of Pharmacotherapy and Experimental TherapeuticsUniversity of North Carolina UNC Eshelman School of PharmacyChapel HillNorth CarolinaUSA
| | - Craig Sykes
- Division of Pharmacotherapy and Experimental TherapeuticsUniversity of North Carolina UNC Eshelman School of PharmacyChapel HillNorth CarolinaUSA
| | - Nicole White
- University of North Carolina School of MedicineChapel HillNorth CarolinaUSA
| | - Angela D. M. Kashuba
- Division of Pharmacotherapy and Experimental TherapeuticsUniversity of North Carolina UNC Eshelman School of PharmacyChapel HillNorth CarolinaUSA
- University of North Carolina School of MedicineChapel HillNorth CarolinaUSA
| | - Julie B. Dumond
- Division of Pharmacotherapy and Experimental TherapeuticsUniversity of North Carolina UNC Eshelman School of PharmacyChapel HillNorth CarolinaUSA
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2
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Abstract
HIV topical microbicides are products with anti-HIV activity, generally incorporating a direct-acting antiretroviral agent, that when applied to the vagina or rectum have the potential to prevent the sexual acquisition of HIV in women and men. Topical microbicides may meet the prevention needs of individuals and groups for whom oral daily forms of pre-exposure prophylaxis (PrEP) have not been acceptable. Microbicides can provide personal control over HIV prevention and offer the possibility of discreet use, qualities that may be particularly important for receptive partners in sexual relationships such as women and transgender women and men, who together account for the clear majority of new HIV infections worldwide. Although the promise of such a product emerged nearly three decades ago, proof of concept has been demonstrated only within the last decade. A robust pipeline of microbicidal gels, films, inserts, and rings has been evaluated in multiple studies among at-risk women and men, and refinement of products for ease of use, reversibility, and high safety is the priority for the field.
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Affiliation(s)
- Jared M Baeten
- Departments of Global Health, Medicine, and Epidemiology, University of Washington, Seattle, Washington 98104, USA;
| | - Craig W Hendrix
- Department of Medicine, Johns Hopkins University, Baltimore, Maryland 21205, USA;
| | - Sharon L Hillier
- Department of Obstetrics, Gynecology, and Reproductive Sciences and Department of Microbiology and Molecular Genetics, University of Pittsburgh, Magee-Womens Research Institute, Pittsburgh, Pennsylvania 15213, USA;
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3
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Hendrix CW. HIV Antiretroviral Pre-Exposure Prophylaxis: Development Challenges and Pipeline Promise. Clin Pharmacol Ther 2018; 104:1082-1097. [PMID: 30199098 PMCID: PMC6925668 DOI: 10.1002/cpt.1227] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Accepted: 08/20/2018] [Indexed: 12/17/2022]
Abstract
The US Food and Drug Administration (FDA) approved oral daily tenofovir/emtricitabine (Truvada) for pre-exposure prophylaxis of human immunodeficiency virus (HIV) infection in 2012 on the basis of two randomized controlled trials (RCTs), one in men who have sex with men (MSM) and another in HIV serodiscordant heterosexual couples. Subsequently, even greater efficacy has been demonstrated in MSM with rapid population-level incidence reductions in some locations. In contrast, studies of antiretroviral pre-exposure prophylaxis (PrEP) in heterosexual women showed only modest or no efficacy, largely attributed to low adherence. The mixed results of antiretroviral-based PrEP bear witness to unique drug development challenges at this complicated intersection of sexual behavior, public health, and drug development. Multiple innovative methods and formulation strategies followed to address unmet medical needs of persons struggling with daily oral PrEP adherence or preference for nonsystemic PrEP options. Clinical pharmacology plays essential roles throughout this PrEP development process, especially in early product development and through pharmacologically informed enhancement and interpretation of clinical trials.
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Affiliation(s)
- Craig W Hendrix
- 1Division of Clinical Pharmacology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
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4
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Ma B, Barth A, McHale CM, Lai MT. Establishment of intracellular tenofovir-diphosphate as the key determinant for in vitro-in vivo translation of antiviral efficacy. Antiviral Res 2018; 151:1-3. [PMID: 29337165 DOI: 10.1016/j.antiviral.2018.01.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2017] [Revised: 01/06/2018] [Accepted: 01/08/2018] [Indexed: 02/07/2023]
Abstract
In vitro evaluation of tenofovir disproxil fumarate (TDF) and tenofovir alafenamide (TAF) revealed comparable antiviral effects with respect to the tenofovir-diphosphate (TFV-DP) level in human peripheral blood mononuclear cells (PBMCs), despite the EC50 values determined based on prodrug concentrations were nearly two orders of magnitude apart. In vivo EC50 obtained from meta-analyses were in good agreement with the in vitro results, indicating intracellular TFV-DP can be employed for in vitro-in vivo translation of viral inhibition for tenofovir prodrugs. Current analysis indicated that the intracellular concentrations of TFV-DP achieving maximal antiviral effect in vitro can be directly translatable in the clinic to accomplish maximal viral load suppression attainable by tenofovir-prodrugs.
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Affiliation(s)
- Bennett Ma
- Pharmacokinetics, Pharmacodynamics and Drug Metabolism, MSD, West Point, PA, 19486, USA.
| | - Aline Barth
- Pharmacokinetics, Pharmacodynamics and Drug Metabolism, MSD, West Point, PA, 19486, USA
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5
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Benson HE, Watterson S, Sharman JL, Mpamhanga CP, Parton A, Southan C, Harmar AJ, Ghazal P. Is systems pharmacology ready to impact upon therapy development? A study on the cholesterol biosynthesis pathway. Br J Pharmacol 2017; 174:4362-4382. [PMID: 28910500 PMCID: PMC5715582 DOI: 10.1111/bph.14037] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2016] [Revised: 08/10/2017] [Accepted: 08/30/2017] [Indexed: 12/22/2022] Open
Abstract
Background and Purpose An ever‐growing wealth of information on current drugs and their pharmacological effects is available from online databases. As our understanding of systems biology increases, we have the opportunity to predict, model and quantify how drug combinations can be introduced that outperform conventional single‐drug therapies. Here, we explore the feasibility of such systems pharmacology approaches with an analysis of the mevalonate branch of the cholesterol biosynthesis pathway. Experimental Approach Using open online resources, we assembled a computational model of the mevalonate pathway and compiled a set of inhibitors directed against targets in this pathway. We used computational optimization to identify combination and dose options that show not only maximal efficacy of inhibition on the cholesterol producing branch but also minimal impact on the geranylation branch, known to mediate the side effects of pharmaceutical treatment. Key Results We describe serious impediments to systems pharmacology studies arising from limitations in the data, incomplete coverage and inconsistent reporting. By curating a more complete dataset, we demonstrate the utility of computational optimization for identifying multi‐drug treatments with high efficacy and minimal off‐target effects. Conclusion and Implications We suggest solutions that facilitate systems pharmacology studies, based on the introduction of standards for data capture that increase the power of experimental data. We propose a systems pharmacology workflow for the refinement of data and the generation of future therapeutic hypotheses.
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Affiliation(s)
- Helen E Benson
- Centre for Integrative Physiology, University of Edinburgh, Edinburgh, UK
| | - Steven Watterson
- Northern Ireland Centre for Stratified Medicine, University of Ulster, C-Tric, Derry, UK
| | - Joanna L Sharman
- Centre for Integrative Physiology, University of Edinburgh, Edinburgh, UK
| | - Chido P Mpamhanga
- Centre for Cardiovascular Science, University of Edinburgh, The Queen's Medical Research Institute, Edinburgh, UK
| | - Andrew Parton
- Northern Ireland Centre for Stratified Medicine, University of Ulster, C-Tric, Derry, UK
| | | | - Anthony J Harmar
- Centre for Cardiovascular Science, University of Edinburgh, The Queen's Medical Research Institute, Edinburgh, UK
| | - Peter Ghazal
- Division of Infection and Pathway Medicine, University of Edinburgh Medical School, Edinburgh, UK.,Centre for Synthetic and Systems Biology, CH Waddington Building, King's Buildings, Edinburgh, UK
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6
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Chen X, Seifert SM, Castillo-Mancilla JR, Bushman LR, Zheng JH, Kiser JJ, MaWhinney S, Anderson PL. Model Linking Plasma and Intracellular Tenofovir/Emtricitabine with Deoxynucleoside Triphosphates. PLoS One 2016; 11:e0165505. [PMID: 27832147 PMCID: PMC5104339 DOI: 10.1371/journal.pone.0165505] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2016] [Accepted: 10/12/2016] [Indexed: 02/07/2023] Open
Abstract
The coformulation of the nucleos(t)ide analogs (NA) tenofovir (TFV) disoproxil fumarate (TDF) and emtricitabine (FTC) is approved for HIV-infection treatment and prevention. Plasma TFV and FTC undergo complicated hybrid processes to form, accumulate, and retain as their active intracellular anabolites: TFV-diphosphate (TFV-DP) and FTC-triphosphate (FTC-TP). Such complexities manifest in nonlinear intracellular pharmacokinetics (PK). In target cells, TFV-DP/FTC-TP compete with endogenous deoxynucleoside triphosphates (dNTP) at the active site of HIV reverse transcriptase, underscoring the importance of analog:dNTP ratios for antiviral efficacy. However, NA such as TFV and FTC have the potential to disturb the dNTP pool, which could augment or reduce their efficacies. We conducted a pharmacokinetics-pharmacodynamics (PKPD) study among forty subjects receiving daily TDF/FTC (300 mg/200 mg) from the first-dose to pharmacological intracellular steady-state (30 days). TFV/FTC in plasma, TFV-DP/FTC-TP and dNTPs in peripheral blood mononuclear cells (PBMC) were quantified using validated LC/MS/MS methodologies. Concentration-time data were analyzed using nonlinear mixed effects modeling (NONMEM). Formations and the accumulation of intracellular TFV-DP/FTC-TP was driven by plasma TFV/FTC, which was described by a hybrid of first-order formation and saturation. An indirect response link model described the interplay between TFV-DP/FTC-TP and the dNTP pool change. The EC50 (interindividual variability, (%CV)) of TFV-DP and FTC-TP on the inhibition of deoxyadenosine triphosphate (dATP) and deoxycytidine triphosphate (dCTP) production were 1020 fmol/106 cells (130%) and 44.4 pmol/106 cells (82.5%), resulting in (90% prediction interval) 11% (0.45%, 53%) and 14% (2.6%, 35%) reductions. Model simulations of analog:dNTP molar ratios using IPERGAY dosing suggested that FTC significantly contributes to the protective effect of preexposure prophylaxis (PrEP). Simulation-based intracellular operational multiple dosing half-lives of TFV-DP and FTC-TP were 6.7 days and 33 hours. This model described the formation of intracellular TFV-DP/FTC-TP and the interaction with dNTPs, and can be used to simulate analog:dNTP time course for various dosing strategies.
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Affiliation(s)
- Xinhui Chen
- University of Colorado, Skaggs School of Pharmacy and Pharmaceutical Sciences, Aurora, CO, United States of America
| | - Sharon M. Seifert
- University of Colorado, Skaggs School of Pharmacy and Pharmaceutical Sciences, Aurora, CO, United States of America
| | - Jose R. Castillo-Mancilla
- University of Colorado, School of Medicine, Division of Infectious Diseases, Aurora, CO, United States of America
| | - Lane R. Bushman
- University of Colorado, Skaggs School of Pharmacy and Pharmaceutical Sciences, Aurora, CO, United States of America
| | - Jia-Hua Zheng
- University of Colorado, Skaggs School of Pharmacy and Pharmaceutical Sciences, Aurora, CO, United States of America
| | - Jennifer J. Kiser
- University of Colorado, Skaggs School of Pharmacy and Pharmaceutical Sciences, Aurora, CO, United States of America
| | - Samantha MaWhinney
- University of Colorado, Colorado School of Public Health, Department of Biostatistics and Informatics, Aurora, CO, United States of America
| | - Peter L. Anderson
- University of Colorado, Skaggs School of Pharmacy and Pharmaceutical Sciences, Aurora, CO, United States of America
- * E-mail:
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7
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Seifert SM, Chen X, Meditz AL, Castillo-Mancilla JR, Gardner EM, Predhomme JA, Clayton C, Austin G, Palmer BE, Zheng JH, Klein B, Kerr BJ, Guida LA, Rower C, Rower JE, Kiser JJ, Bushman LR, MaWhinney S, Anderson PL. Intracellular Tenofovir and Emtricitabine Anabolites in Genital, Rectal, and Blood Compartments from First Dose to Steady State. AIDS Res Hum Retroviruses 2016; 32:981-991. [PMID: 27526873 DOI: 10.1089/aid.2016.0008] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
The pharmacokinetics (PK) of tenofovir-diphosphate (TFV-DP) and emtricitabine-triphosphate (FTC-TP), the active anabolites of tenofovir disoproxil fumarate (TDF), and emtricitabine (FTC) in blood, genital, and rectal compartments was determined in HIV-positive and seronegative adults who undertook a 60-day intensive PK study of daily TDF/FTC (plus efavirenz in HIV positives). Lymphocyte cell sorting, genital, and rectal sampling occurred once per subject, at staggered visits. Among 19 HIV-positive (3 female) and 21 seronegative (10 female) adults, TFV-DP in peripheral blood mononuclear cells (PBMC) accumulated 8.6-fold [95% confidence interval (CI): 7.2-10] from first-dose to steady-state concentration (Css) versus 1.7-fold (95% CI: 1.5-1.9) for FTC-TP. Css was reached in ∼11 and 3 days, respectively. Css values were similar between HIV-negative and HIV-positive individuals. Css TFV-DP in rectal mononuclear cells (1,450 fmol/106 cells, 898-2,340) was achieved in 5 days and was >10 times higher than PBMC (95 fmol/106 cells, 85-106), seminal cells (22 fmol/106 cells, 6-79), and cervical cells (111 fmol/106 cells, 64-194). FTC-TP Css was highest in PBMC (5.7 pmol/106 cells, 5.2-6.1) and cervical cells (7 pmol/106 cells, 2-19) versus rectal (0.8 pmol/106 cells, 0.6-1.1) and seminal cells (0.3 pmol/106 cells, 0.2-0.5). Genital drug concentrations on days 1-7 overlapped with estimated Css, but accumulation characteristics were based on limited data. TFV-DP and FTC-TP in cell sorted samples were highest and achieved most rapidly in CD14+ compared with CD4+, CD8+, and CD19+ cells. Together, these findings demonstrate cell-type and tissue-dependent cellular pharmacology, preferential accumulation of TFV-DP in rectal mononuclear cells, and rapid distribution into rectal and genital compartments.
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Affiliation(s)
- Sharon M. Seifert
- Department of Pharmaceutical Sciences, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado Denver Anschutz Medical Campus, Aurora, Colorado
| | - Xinhui Chen
- Department of Pharmaceutical Sciences, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado Denver Anschutz Medical Campus, Aurora, Colorado
| | - Amie L. Meditz
- Boulder Community Hospital, Beacon Center for Infectious Diseases, Boulder, Colorado
| | - Jose R. Castillo-Mancilla
- Division of Infectious Diseases, School of Medicine, University of Colorado Denver Anschutz Medical Campus, Aurora, Colorado
| | | | - Julie A. Predhomme
- Department of Pharmaceutical Sciences, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado Denver Anschutz Medical Campus, Aurora, Colorado
| | - Carolyn Clayton
- Department of Biostatistics and Informatics, University of Colorado Denver Anschutz Medical Campus, Aurora, Colorado
| | - Gregory Austin
- School of Medicine, Internal Medicine, Gastroenterology, University of Colorado Denver Anschutz Medical Campus, Aurora, Colorado
| | - Brent E. Palmer
- Division of Allergy and Clinical Immunology, School of Medicine, University of Colorado Denver Anschutz Medical Campus, Aurora, Colorado
| | - Jia-Hua Zheng
- Department of Pharmaceutical Sciences, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado Denver Anschutz Medical Campus, Aurora, Colorado
| | - Brandon Klein
- Department of Pharmaceutical Sciences, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado Denver Anschutz Medical Campus, Aurora, Colorado
| | - Becky J. Kerr
- Department of Pharmaceutical Sciences, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado Denver Anschutz Medical Campus, Aurora, Colorado
| | - L. Anthony Guida
- Department of Pharmaceutical Sciences, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado Denver Anschutz Medical Campus, Aurora, Colorado
| | - Caitlin Rower
- Department of Pharmaceutical Sciences, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado Denver Anschutz Medical Campus, Aurora, Colorado
| | - Joseph E. Rower
- Department of Pharmaceutical Sciences, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado Denver Anschutz Medical Campus, Aurora, Colorado
| | - Jennifer J. Kiser
- Department of Pharmaceutical Sciences, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado Denver Anschutz Medical Campus, Aurora, Colorado
| | - Lane R. Bushman
- Department of Pharmaceutical Sciences, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado Denver Anschutz Medical Campus, Aurora, Colorado
| | - Samantha MaWhinney
- Department of Biostatistics and Informatics, University of Colorado Denver Anschutz Medical Campus, Aurora, Colorado
| | - Peter L. Anderson
- Department of Pharmaceutical Sciences, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado Denver Anschutz Medical Campus, Aurora, Colorado
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8
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Duwal S, Sunkara V, von Kleist M. Multiscale Systems-Pharmacology Pipeline to Assess the Prophylactic Efficacy of NRTIs Against HIV-1. CPT Pharmacometrics Syst Pharmacol 2016; 5:377-87. [PMID: 27439573 PMCID: PMC4961081 DOI: 10.1002/psp4.12095] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2016] [Revised: 06/20/2016] [Accepted: 06/20/2016] [Indexed: 12/14/2022] Open
Abstract
While HIV-1 continues to spread, the use of antivirals in preexposure prophylaxis (PrEP) has recently been suggested. Here we present a modular systems pharmacology modeling pipeline, predicting PrEP efficacy of nucleotide reverse transcriptase inhibitors (NRTIs) at the scale of reverse transcription, target-cell, and systemic infection and after repeated viral exposures, akin to clinical trials. We use this pipeline to benchmark the prophylactic efficacy of all currently approved NRTIs in wildtype and mutant viruses. By integrating pharmacokinetic models, we find that intracellular tenofovir-diphosphate builds up too slowly to halt infection when taken "on demand" and that lamivudine may substitute emtricitabine in PrEP combinations. Lastly, we delineate factors confounding clinical PrEP efficacy estimates and provide a method to overcome these. The presented framework is useful to screen and optimize PrEP candidates and strategies and to understand their clinical efficacy by integrating the diverse scales which determine PrEP efficacy.
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Affiliation(s)
- S Duwal
- Department of Mathematics & Computer ScienceFreie Universität BerlinBerlinGermany
| | - V Sunkara
- Department of Mathematics & Computer ScienceFreie Universität BerlinBerlinGermany
- Konrad‐Zuse‐Institut für InformationstechnikBerlinGermany
| | - M von Kleist
- Department of Mathematics & Computer ScienceFreie Universität BerlinBerlinGermany
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9
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Biliouris K, Lavielle M, Trame MN. MatVPC: A User-Friendly MATLAB-Based Tool for the Simulation and Evaluation of Systems Pharmacology Models. CPT-PHARMACOMETRICS & SYSTEMS PHARMACOLOGY 2015; 4:547-57. [PMID: 26451334 PMCID: PMC4592534 DOI: 10.1002/psp4.12011] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/27/2015] [Accepted: 07/10/2015] [Indexed: 12/13/2022]
Abstract
Quantitative systems pharmacology (QSP) models are progressively entering the arena of contemporary pharmacology. The efficient implementation and evaluation of complex QSP models necessitates the development of flexible computational tools that are built into QSP mainstream software. To this end, we present MatVPC, a versatile MATLAB-based tool that accommodates QSP models of any complexity level. MatVPC executes Monte Carlo simulations as well as automatic construction of visual predictive checks (VPCs) and quantified VPCs (QVPCs).
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Affiliation(s)
- K Biliouris
- Center for Pharmacometrics and Systems Pharmacology, Department of Pharmaceutics, University of Florida Orlando, Florida, USA
| | | | - M N Trame
- Center for Pharmacometrics and Systems Pharmacology, Department of Pharmaceutics, University of Florida Orlando, Florida, USA
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10
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Plasma Tenofovir, Emtricitabine, and Rilpivirine and Intracellular Tenofovir Diphosphate and Emtricitabine Triphosphate Pharmacokinetics following Drug Intake Cessation. Antimicrob Agents Chemother 2015. [PMID: 26195515 DOI: 10.1128/aac.01441-15] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Pharmacokinetic (PK) data describing a prolonged time course of antiretrovirals in plasma and peripheral blood mononuclear cells (PBMCs) are important for understanding and managing late or missed doses and to assess the appropriateness of compounds for preexposure prophylaxis (PrEP). This study aimed to evaluate the PK of coformulated tenofovir disoproxil fumarate (DF), emtricitabine, and rilpivirine in plasma and of the intracellular (IC) anabolites tenofovir diphosphate (TFV-DP) and emtricitabine triphosphate (FTC-TP) in healthy volunteers up to 9 days after drug cessation. Individuals received daily tenofovir DF-emtricitabine-rilpivirine (245/200/25 mg) for 14 days. Drug intake was stopped, and serial sampling occurred prior to the final dose and up to 216 h (9 days) after stopping drug intake. Concentrations were quantified and PK parameters calculated. Eighteen volunteers completed the study. The terminal elimination plasma half-lives for tenofovir and emtricitabine over 216 h (geometric mean [90% confidence interval]) were higher than those seen over 0 to 24 h (for tenofovir, 31 h [27 to 40 h] versus 13.3 h [12.5 to 15.1 h]; for emtricitabine, 41 h [36 to 54 h] versus 6.4 h (5.9 to 7.6 h]). Model-predicted IC half-lives (0 to 168 h) were 116 h (TFV-DP) and 37 h (FTC-TP). The plasma rilpivirine concentration at 216 h was 4.5 ng/ml (4.2 to 6.2 ng/ml), and half-lives over 0 to 216 h and 0 to 24 h were 47 h (41 to 59 h) and 35 h (28 to 46 h), respectively. These data contribute to our understanding of drug behavior following treatment interruption; however, adherence to therapy should be promoted. Validated plasma and IC target concentrations are necessary to allow interpretation with respect to sustained virus suppression or HIV prevention. (The trial was conducted in accordance with the Declaration of Helsinki [EudraCT 2012-002781-13].).
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11
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Gunawardana M, Remedios-Chan M, Miller CS, Fanter R, Yang F, Marzinke MA, Hendrix CW, Beliveau M, Moss JA, Smith TJ, Baum MM. Pharmacokinetics of long-acting tenofovir alafenamide (GS-7340) subdermal implant for HIV prophylaxis. Antimicrob Agents Chemother 2015; 59:3913-9. [PMID: 25896688 PMCID: PMC4468692 DOI: 10.1128/aac.00656-15] [Citation(s) in RCA: 133] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2015] [Accepted: 04/12/2015] [Indexed: 12/28/2022] Open
Abstract
Oral or topical daily administration of antiretroviral (ARV) drugs to HIV-1-negative individuals in vulnerable populations is a promising strategy for HIV-1 prevention. Adherence to the dosing regimen has emerged as a critical factor determining efficacy outcomes of clinical trials. Because adherence to therapy is inversely related to the dosing period, sustained release or long-acting ARV formulations hold significant promise for increasing the effectiveness of HIV-1 preexposure prophylaxis (PrEP) by reducing dosing frequency. A novel, subdermal implant delivering the potent prodrug tenofovir alafenamide (TAF) with controlled, sustained, zero-order (linear) release characteristics is described. A candidate device delivering TAF at 0.92 mg day(-1) in vitro was evaluated in beagle dogs over 40 days for pharmacokinetics and preliminary safety. No adverse events related to treatment with the test article were noted during the course of the study, and no significant, unusual abnormalities were observed. The implant maintained a low systemic exposure to TAF (median, 0.85 ng ml(-1); interquartile range [IQR], 0.60 to 1.50 ng ml(-1)) and tenofovir (TFV; median, 15.0 ng ml(-1); IQR, 8.8 to 23.3 ng ml(-1)), the product of in vivo TAF hydrolysis. High concentrations (median, 512 fmol/10(6) cells over the first 35 days) of the pharmacologically active metabolite, TFV diphosphate, were observed in peripheral blood mononuclear cells at levels over 30 times higher than those associated with HIV-1 PrEP efficacy in humans. Our report on the first sustained-release nucleoside reverse transcriptase inhibitor (NRTI) for systemic delivery demonstrates a successful proof of principle and holds significant promise as a candidate for HIV-1 prophylaxis in vulnerable populations.
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Affiliation(s)
- Manjula Gunawardana
- Department of Chemistry, Oak Crest Institute of Science, Monrovia, California, USA
| | | | - Christine S Miller
- Department of Chemistry, Oak Crest Institute of Science, Monrovia, California, USA
| | - Rob Fanter
- Department of Chemistry, Oak Crest Institute of Science, Monrovia, California, USA
| | - Flora Yang
- Department of Chemistry, Oak Crest Institute of Science, Monrovia, California, USA
| | - Mark A Marzinke
- Department of Medicine, Johns Hopkins University, Baltimore, Maryland, USA Department of Pathology, Johns Hopkins University, Baltimore, Maryland, USA
| | - Craig W Hendrix
- Department of Medicine, Johns Hopkins University, Baltimore, Maryland, USA
| | | | - John A Moss
- Department of Chemistry, Oak Crest Institute of Science, Monrovia, California, USA
| | - Thomas J Smith
- Department of Chemistry, Oak Crest Institute of Science, Monrovia, California, USA Auritec Pharmaceuticals, Inc., Pasadena, California, USA
| | - Marc M Baum
- Department of Chemistry, Oak Crest Institute of Science, Monrovia, California, USA
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