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Lartey M, Ganu VJ, Tachi K, Yang H, Anderson PL, Langaee T, Ojewale O, Boamah I, Obo-Akwa A, Antwi K, Bushman LR, Ellison L, Kwara A. Association of tenofovir diphosphate and lamivudine triphosphate concentrations with HIV and hepatitis B virus viral suppression. AIDS 2024; 38:351-362. [PMID: 37861682 PMCID: PMC10842673 DOI: 10.1097/qad.0000000000003764] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Accepted: 10/11/2023] [Indexed: 10/21/2023]
Abstract
OBJECTIVE Concentrations of tenofovir diphosphate (TFV-DP) and lamivudine triphosphate (3TC-TP) in cells are correlates of medication adherence and antiviral activity. However, studies have yet to characterize the simultaneous relationship between TFV-DP and 3TC-TP concentrations with HIV and hepatitis B virus (HBV) suppression. METHODS Individuals with HIV/HBV coinfection on tenofovir disoproxil fumarate (TDF)-containing antiretroviral therapy (ART) were enrolled. Peripheral blood mononuclear cells (PBMCs) and dried blood spots (DBS) samples were collected and steady-state TFV-DP and 3TC-TP concentrations quantified using validated methods. The relationship between patient factors, TFV-DP, and 3TC-TP concentrations in PBMCs and DBS with HBV and HIV viral suppression were examined. RESULTS Of 138 participants on TDF-containing ART for a median duration (range) of 6 (0.75-15) years, the median age was 43 years and 64% were women. Overall, 128 (92.8%) and 129 (93.5%) had suppressed HIV and HBV viral loads, respectively. Of the 128 participants with suppressed HIV, 122 (95.3%) had suppressed HBV. Self-reported ART adherence, recent change to dolutegravir-based ART, TFV-DP, and 3TC-TP concentrations in PBMCs and DBS were associated with HIV RNA suppression, while HBe antigen positivity, HIV suppression, and TFV-DP concentrations in DBS were associated with HBV DNA suppression (including six persons with HBV nonsuppression and HIV suppression). CONCLUSION Long-term TDF/3TC-conatining ART was highly efficacious in individuals with HIV/HBV coinfection. Higher TFV-DP concentrations were predictive of suppression for both viruses. Persistent HBV viremia on TDF/3TC-containg ART requires additional research, but may represent poor adherence and the need for adherence interventions or novel antivirals.
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Affiliation(s)
- Margaret Lartey
- Department of Medicine and Therapeutics, University of Ghana Medical School
- Department of Medicine, Korle-Bu Teaching Hospital, Accra, Ghana
| | - Vincent J. Ganu
- Department of Medicine, Korle-Bu Teaching Hospital, Accra, Ghana
| | - Kenneth Tachi
- Department of Medicine and Therapeutics, University of Ghana Medical School
- Department of Medicine, Korle-Bu Teaching Hospital, Accra, Ghana
| | - Hongmei Yang
- Department of Biostatistics and Computational Biology, University of Rochester School of Medicine and Dentistry, Rochester, New York
| | - Peter L. Anderson
- Colorado Antiviral Pharmacology Laboratory and Department of Pharmaceutical Sciences, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado-Anschutz Medical Campus, Aurora, Colorado
| | - Taimour Langaee
- Department of Pharmacotherapy and Translational Research and Center for Pharmacogenomics and Precision Medicine, College of Pharmacy, University of Florida
| | - Oluwayemisi Ojewale
- Department of Medicine, University of Florida College of Medicine, Gainesville, Florida, USA
| | - Isaac Boamah
- Department of Microbiology, School of Biomedical and Allied Health Sciences, Accra, Ghana
| | - Adjoa Obo-Akwa
- Department of Medicine and Therapeutics, University of Ghana Medical School
| | - Kenneth Antwi
- Department of Medicine, Korle-Bu Teaching Hospital, Accra, Ghana
| | - Lane R. Bushman
- Colorado Antiviral Pharmacology Laboratory and Department of Pharmaceutical Sciences, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado-Anschutz Medical Campus, Aurora, Colorado
| | - Lucas Ellison
- Colorado Antiviral Pharmacology Laboratory and Department of Pharmaceutical Sciences, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado-Anschutz Medical Campus, Aurora, Colorado
| | - Awewura Kwara
- Department of Medicine, University of Florida College of Medicine, Gainesville, Florida, USA
- Medical Service, North Florida South Georgia Veterans Health System, Gainesville, Florida, USA
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Jia X, Kullik GA, Bufano M, Brancale A, Schols D, Meier C. Membrane-permeable tenofovir-di- and monophosphate analogues. Eur J Med Chem 2024; 264:116020. [PMID: 38086193 DOI: 10.1016/j.ejmech.2023.116020] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2023] [Revised: 11/28/2023] [Accepted: 11/28/2023] [Indexed: 12/30/2023]
Abstract
The development of new antiviral agents such as nucleoside analogues or acyclic nucleotide analogues (ANPs) and prodrugs thereof is an ongoing task. We report on the synthesis of three types of lipophilic triphosphate analogues of (R)-PMPA and dialkylated diphosphate analogues of (R)-PMPA. A highly selective release of the different nucleotide analogues ((R)-PMPA-DP, (R)-PMPA-MP, and (R)-PMPA) from these compounds was achieved. All dialkylated (R)-PMPA-prodrugs proved to be very stable in PBS as well as in CEM/0 cell extracts and human plasma. In primer extension assays, both the monoalkylated and the dialkylated (R)-PMPA-DP derivatives acted as (R)-PMPA-DP as a substrate for HIV-RT. In contrast, no incorporation events were observed using human polymerase γ. The dialkylated (R)-PMPA-compounds exhibited significant anti-HIV efficacy in HIV-1/2 infected cells (CEM/0 and CEM/TK-). Remarkably, the dialkylated (R)-PMPA-MP derivative 9a showed a 326-fold improved activity as compared to (R)-PMPA in HIV-2 infected CEM/TK- cells as well as a very high SI of 14,000. We are convinced that this study may significantly contribute to advancing antiviral agents developed based on nucleotide analogues in the future.
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Affiliation(s)
- Xiao Jia
- Organic Chemistry, Department of Chemistry, Faculty of Mathematics, Informatics and Natural Sciences, Universität Hamburg, Martin-Luther-King-Platz 6, D-20146, Hamburg, Germany
| | - Giuliano A Kullik
- Organic Chemistry, Department of Chemistry, Faculty of Mathematics, Informatics and Natural Sciences, Universität Hamburg, Martin-Luther-King-Platz 6, D-20146, Hamburg, Germany
| | - Marianna Bufano
- Dipartimento Chimica e Tecnologie del Farmaco, Facoltà di Farmacia e Medicina, University of Rome "La Sapienza", Piazzale Aldo Moro 5, 00185, Rome, Italy
| | - Andrea Brancale
- Department of Organic Chemistry, Vysoká Škola Chemicko-Technologická v Praze, Technická 5, 16628, Prague, Czech Republic
| | - Dominique Schols
- Laboratory of Virology and Chemotherapy, Department of Microbiology and Immunology and Transplantation, Rega Institute for Medical Research, KU Leuven, Herestraat 49, B-3000, Leuven, Belgium
| | - Chris Meier
- Organic Chemistry, Department of Chemistry, Faculty of Mathematics, Informatics and Natural Sciences, Universität Hamburg, Martin-Luther-King-Platz 6, D-20146, Hamburg, Germany; Centre for Structural Systems Biology (CSSB), Hamburg, DESY Campus, Notkestrasse 85, D-22607, Hamburg, Germany.
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Colón Ortiz R, Knerler S, Fridman LB, Mercado A, Price AS, Rosado-Franco JJ, Wilkins H, Flores BR, Orsburn BC, Williams DW. Cocaine regulates antiretroviral therapy CNS access through pregnane-x receptor-mediated drug transporter and metabolizing enzyme modulation at the blood brain barrier. Fluids Barriers CNS 2024; 21:5. [PMID: 38200564 PMCID: PMC10777548 DOI: 10.1186/s12987-023-00507-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2023] [Accepted: 12/28/2023] [Indexed: 01/12/2024] Open
Abstract
BACKGROUND Appropriate interactions between antiretroviral therapies (ART) and drug transporters and metabolizing enzymes at the blood brain barrier (BBB) are critical to ensure adequate dosing of the brain to achieve HIV suppression. These proteins are modulated by demographic and lifestyle factors, including substance use. While understudied, illicit substances share drug transport and metabolism pathways with ART, increasing the potential for adverse drug:drug interactions. This is particularly important when considering the brain as it is relatively undertreated compared to peripheral organs and is vulnerable to substance use-mediated damage. METHODS We used an in vitro model of the human BBB to determine the extravasation of three first-line ART drugs, emtricitabine (FTC), tenofovir (TFV), and dolutegravir (DTG), in the presence and absence of cocaine, which served as our illicit substance model. The impact of cocaine on BBB integrity and permeability, drug transporters, metabolizing enzymes, and their master transcriptional regulators were evaluated to determine the mechanisms by which substance use impacted ART central nervous system (CNS) availability. RESULTS We determined that cocaine had a selective impact on ART extravasation, where it increased FTC's ability to cross the BBB while decreasing TFV. DTG concentrations that passed the BBB were below quantifiable limits. Interestingly, the potent neuroinflammatory modulator, lipopolysaccharide, had no effect on ART transport, suggesting a specificity for cocaine. Unexpectedly, cocaine did not breach the BBB, as permeability to albumin and 4 kDa FITC-dextran, as well as tight junction proteins and adhesion molecules remained unchanged. Rather, cocaine selectively decreased the pregnane-x receptor (PXR), but not constitutive androstane receptor (CAR). Consequently, drug transporter expression and activity decreased in endothelial cells of the BBB, including p-glycoprotein (P-gp), breast cancer resistance protein (BCRP), and multidrug resistance-associated protein 4 (MRP4). Further, cytochrome P450 3A4 (CYP3A4) enzymatic activity increased following cocaine treatment that coincided with decreased expression. Finally, cocaine modulated adenylate kinases that are required to facilitate biotransformation of ART prodrugs to their phosphorylated, pharmacologically active counterparts. CONCLUSION Our findings indicate that additional considerations are needed in CNS HIV treatment strategies for people who use cocaine, as it may limit ART efficacy through regulation of drug transport and metabolizing pathways at the BBB.
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Affiliation(s)
- Rodnie Colón Ortiz
- Department of Neuroscience, Johns Hopkins School of Medicine, Baltimore, MD, 21205, USA
| | - Stephen Knerler
- Department of Molecular and Comparative Pathobiology, Johns Hopkins School of Medicine, Baltimore, MD, 21205, USA
| | - Lisa B Fridman
- Department of Molecular and Comparative Pathobiology, Johns Hopkins School of Medicine, Baltimore, MD, 21205, USA
| | - Alicia Mercado
- Department of Molecular and Comparative Pathobiology, Johns Hopkins School of Medicine, Baltimore, MD, 21205, USA
| | - Amira-Storm Price
- Department of Molecular and Comparative Pathobiology, Johns Hopkins School of Medicine, Baltimore, MD, 21205, USA
| | - Jose J Rosado-Franco
- Department of Molecular and Comparative Pathobiology, Johns Hopkins School of Medicine, Baltimore, MD, 21205, USA
| | - Hannah Wilkins
- Department of Pharmacology and Molecular Sciences, Johns Hopkins School of Medicine, Baltimore, MD, 21205, USA
| | - Bianca R Flores
- Department of Molecular and Comparative Pathobiology, Johns Hopkins School of Medicine, Baltimore, MD, 21205, USA
| | - Benjamin C Orsburn
- Department of Pharmacology and Molecular Sciences, Johns Hopkins School of Medicine, Baltimore, MD, 21205, USA
| | - Dionna W Williams
- Department of Neuroscience, Johns Hopkins School of Medicine, Baltimore, MD, 21205, USA.
- Department of Molecular and Comparative Pathobiology, Johns Hopkins School of Medicine, Baltimore, MD, 21205, USA.
- Department of Pharmacology and Molecular Sciences, Johns Hopkins School of Medicine, Baltimore, MD, 21205, USA.
- Department of Medicine, Division of Clinical Pharmacology, Johns Hopkins School of Medicine, Baltimore, MD, 21205, USA.
- Department of Molecular Microbiology & Immunology, Johns Hopkins School of Public Health, Baltimore, MD, 21205, USA.
- Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Rollins Research Center, 1510 Clifton Road NE, 30322, Atlanta, Georgia.
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Gupta A, Laha JK. Growing Utilization of Radical Chemistry in the Synthesis of Pharmaceuticals. CHEM REC 2023; 23:e202300207. [PMID: 37565381 DOI: 10.1002/tcr.202300207] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Revised: 07/19/2023] [Indexed: 08/12/2023]
Abstract
Our current unhealthy lifestyle and the exponential surge in the population getting affected by a variety of diseases have made pharmaceuticals or drugs an imperative part of life, making the development of innovative strategies for drug discovery or the introduction of refined, cost-effective and modern technologies for the synthesis of clinically used drugs, a need of the hour. Ever since their discovery, free radicals and radical cations or anions as reactive intermediates have captivated the chemists, resulting in an exceptional utilization of these moieties throughout the field of chemical synthesis, owing to their unprecedented and widespread reactivity. Sticking with the idea of not judging the book by its cover, despite the conventional thought process of radicals being unstable and difficult to control entities, scientists and academicians around the globe have done an appreciable amount of work utilizing both persistent as well as transient radicals for a variety of organic transformations, exemplifying them with the synthesis of significant biologically active pharmaceutical ingredients. This review truly accounts for the organic radical transformations including radical addition, radical cascade cyclization, radical/radical cross-coupling, coupling with metal-complexes and radical cations coupling with nucleophiles, that offers fascinating and unconventional approaches towards the construction of intricate structural frameworks of marketed APIs with high atom- and step-economy; complementing the otherwise employed traditional methods. This tutorial review presents a comprehensive package of diverse methods utilized for radical generation, featuring their reactivity to form critical bonds in pharmaceutical total synthesis or in building key starting materials or intermediates of their synthetic journey, acknowledging their excellence, downsides and underlying mechanisms, which are otherwise poorly highlighted in the literature. Despite great achievements over the past few decades in this area, many challenges and obstacles are yet to be unraveled to shorten the distance between the academics and the industry, which are all discussed in summary and outlook.
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Affiliation(s)
- Anjali Gupta
- Department of Pharmaceutical Technology (Process Chemistry), National Institute of Pharmaceutical Education & Research (NIPER) S.A.S. Nagar, Sahibzada Ajit Singh Nagar, Mohali, 160062, India
| | - Joydev K Laha
- Department of Pharmaceutical Technology (Process Chemistry), National Institute of Pharmaceutical Education & Research (NIPER) S.A.S. Nagar, Sahibzada Ajit Singh Nagar, Mohali, 160062, India
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Fridman LB, Knerler S, Price AS, Ortiz RC, Mercado A, Wilkins H, Flores BR, Orsburn BC, Williams DW. Cocaine Regulates Antiretroviral Therapy CNS Access Through Pregnane-X Receptor-Mediated Drug Transporter and Metabolizing Enzyme Modulation at the Blood Brain Barrier. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.07.28.551042. [PMID: 37546800 PMCID: PMC10402182 DOI: 10.1101/2023.07.28.551042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/08/2023]
Abstract
Background Appropriate interactions between antiretroviral therapies (ART) and drug transporters and metabolizing enzymes at the blood brain barrier (BBB) are critical to ensure adequate dosing of the brain to achieve HIV suppression. These proteins are modulated by demographic and lifestyle factors, including substance use. While understudied, illicit substances share drug transport and metabolism pathways with ART, increasing the potential for adverse drug:drug interactions. This is particularly important when considering the brain as it is relatively undertreated compared to peripheral organs and is vulnerable to substance use-mediated damage. Methods We used an in vitro model of the human BBB to determine the extravasation of three first-line ART drugs, emtricitabine (FTC), tenofovir (TFV), and dolutegravir (DTG), in the presence and absence of cocaine, which served as our illicit substance model. The impact of cocaine on BBB integrity and permeability, drug transporters, metabolizing enzymes, and their master transcriptional regulators were evaluated to determine the mechanisms by which substance use impacted ART central nervous system (CNS) availability. Results We determined that cocaine had a selective impact on ART extravasation, where it increased FTC's ability to cross the BBB while decreasing TFV. DTG concentrations that passed the BBB were below quantifiable limits. Interestingly, the potent neuroinflammatory modulator, lipopolysaccharide, had no effect on ART transport, suggesting a specificity for cocaine. Unexpectedly, cocaine did not breach the BBB, as permeability to albumin and tight junction proteins and adhesion molecules remained unchanged. Rather, cocaine selectively decreased the pregnane-x receptor (PXR), but not constitutive androstane receptor (CAR). Consequently, drug transporter expression and activity decreased in endothelial cells of the BBB, including p-glycoprotein (P-gp), breast cancer resistance protein (BCRP), and multidrug resistance-associated protein 4 (MRP4). Further, cytochrome P450 3A4 (CYP3A4) enzymatic activity increased following cocaine treatment that coincided with decreased expression. Finally, cocaine modulated adenylate kinases are required to facilitate biotransformation of ART prodrugs to their phosphorylated, pharmacologically active counterparts. Conclusion Our findings indicate that additional considerations are needed in CNS HIV treatment strategies for people who use cocaine, as it may limit ART efficacy through regulation of drug transport and metabolizing pathways at the BBB.
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Affiliation(s)
- Lisa B. Fridman
- Department of Molecular and Comparative Pathobiology, Johns Hopkins School of Medicine, Baltimore, Maryland 21205
| | - Stephen Knerler
- Department of Molecular and Comparative Pathobiology, Johns Hopkins School of Medicine, Baltimore, Maryland 21205
| | - Amira-Storm Price
- Department of Molecular and Comparative Pathobiology, Johns Hopkins School of Medicine, Baltimore, Maryland 21205
| | - Rodnie Colón Ortiz
- Department of Neuroscience, Johns Hopkins School of Medicine, Baltimore, Maryland 21205
| | - Alicia Mercado
- Department of Molecular and Comparative Pathobiology, Johns Hopkins School of Medicine, Baltimore, Maryland 21205
| | - Hannah Wilkins
- Department of Pharmacology and Molecular Sciences, Johns Hopkins School of Medicine, Baltimore, Maryland 21205
| | - Bianca R. Flores
- Department of Molecular and Comparative Pathobiology, Johns Hopkins School of Medicine, Baltimore, Maryland 21205
| | - Benjamin C. Orsburn
- Department of Pharmacology and Molecular Sciences, Johns Hopkins School of Medicine, Baltimore, Maryland 21205
| | - Dionna W. Williams
- Department of Molecular and Comparative Pathobiology, Johns Hopkins School of Medicine, Baltimore, Maryland 21205
- Department of Neuroscience, Johns Hopkins School of Medicine, Baltimore, Maryland 21205
- Department of Pharmacology and Molecular Sciences, Johns Hopkins School of Medicine, Baltimore, Maryland 21205
- Department of Medicine, Division of Clinical Pharmacology, Johns Hopkins School of Medicine, Baltimore, Maryland 21205
- Department of Molecular Microbiology & Immunology, Johns Hopkins School of Public Health, Baltimore, Maryland 21205
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Tenofovir-diphosphate in peripheral blood mononuclear cells during low, medium and high adherence to emtricitabine/ tenofovir alafenamide vs. emtricitabine/ tenofovir disoproxil fumarate. AIDS 2021; 35:2481-2487. [PMID: 34482350 DOI: 10.1097/qad.0000000000003062] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
OBJECTIVE Tenofovir alafenamide (TAF) preferentially loads peripheral blood mononuclear cells (PBMCs), resulting in higher PBMC tenofovir-diphosphate (TFV-DP) vs. tenofovir disoproxil fumarate (TDF). No studies have yet compared TFV-DP in PBMC from lower than daily dosing between prodrugs, which has potential implications for event-driven preexposure prophylaxis and pharmacologic forgiveness. DESIGN Two separate randomized, directly observed therapy (DOT) crossover studies (DOT-DBS and TAF-DBS) were conducted to mimic low, medium and high adherence. METHODS HIV-negative adults were randomized to two 12-week DOT regimens of 33, 67 or 100% of daily dosing with emtricitabine (F)/TAF 200 mg/25 mg (TAF-DBS) or F/TDF 200 mg/300 mg (DOT-DBS), separated by a 12-week washout. PBMC steady-state concentrations (Css) of TFV-DP and FTC-TP were estimated using nonlinear mixed models and compared between F/TAF and F/TDF. RESULTS Thirty-five participants contributed to 33% (n = 23), 67% (n = 23) and 100% (n = 23) of daily F/TAF regimens. Forty-four contributed to 33% (n = 15), 67% (n = 16) and 100% (n = 32) of daily F/TDF regimens. PBMC TFV-DP Css were 7.3 [95% confidence interval (95% CI): 6.4-8.2], 7.1 (5.9-8.2) and 6.7- (4.4-8.9) fold higher (P < 0.0001) following F/TAF vs. F/TDF; 593 vs. 81.7, 407 vs. 57.4, and 215 vs. 32.3 fmol/106 cells, respectively. TFV-DP was 2.6 (2.1-3.1) fold higher with 33% F/TAF vs. 100% F/TDF. Estimated half-lives (95% CI) of TFV-DP in PBMC were 2.9 (1.5-5.5) days for F/TAF and 2.1 (1.5-2.9) days for F/TDF. FTC-TP was similar in both studies (P = 0.119). CONCLUSION F/TAF produced 6.7 to 7.3-fold higher TFV-DP in PBMC vs. F/TDF across adherence levels, supporting increased potency and pharmacologic forgiveness with F/TAF in the PBMC compartment.
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Ağın F, Doğan İS. Voltammetric Methods Used in the Determination of Nucleoside Reverse Transcriptase Inhibitors. CURR PHARM ANAL 2021. [DOI: 10.2174/1573412916999200519141257] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Background:
The Human Immunodeficiency Virus (HIV) has now been established as the
causative agent of the Acquired Immunodeficiency Syndrome (AIDS) and exactly 25 antiretroviral
drugs have been formally approved for clinical use in the treatment of AIDS. The life quality and duration
of HIV-positive patients have increased with the usage of antiretroviral drugs in the treatment of
AIDS. Nucleoside Reverse Transcriptase Inhibitors (NRTIs) are one of the subgroups of antiretroviral.
Objective:
The quantification of drugs is important, as they make positive contributions to dose adjustments
in practice. Voltammetric methods are very powerful analytical methods used in the pharmaceutical
industry because of the determination of therapeutic agents and/or their metabolites in clinical
samples at extremely low concentrations (10-50 ng/ml).
Methods:
This review mainly includes the pharmacological properties and recent determination studies
by voltammetric methods from pharmaceutical dosage forms and biological samples of eight NRTIs
group antiretroviral drugs (zidovudine, abacavir, adefovir, entecavir, zalcitabine, didanosine, emtricitabine,
lamivudine) that are used in the clinic and show electroactive properties, were performed.
Conclusion:
Due to the variety of working electrodes in voltammetric methods, it is possible to choose
the electrode that best responds. In this way, the analysis of NRTIs was possible at lower concentrations
in pharmaceuticals and biological samples with voltammetric methods in these studies without
the necessity for the sample pre-treatment or time-consuming extraction steps. The voltammetric methods
provide good stability, repeatability, reproducibility and high recovery for the analysis of the analyte.
They could be used for the pharmacokinetic studies as well as for quality control laboratory studies.
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Affiliation(s)
- Fatma Ağın
- Department of Analytical Chemistry, Faculty of Pharmacy, Karadeniz Technical University, Trabzon,Turkey
| | - İnci Selin Doğan
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Karadeniz Technical University, Trabzon,Turkey
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Abstract
The current focus for many researchers has turned to the development of therapeutics that have the potential for serving as broad-spectrum inhibitors that can target numerous viruses, both within a particular family, as well as to span across multiple viral families. This will allow us to build an arsenal of therapeutics that could be used for the next outbreak. In that regard, nucleosides have served as the cornerstone for antiviral therapy for many decades. As detailed herein, many nucleosides have been shown to inhibit multiple viruses due to the conserved nature of many viral enzyme binding sites. Thus, it is somewhat surprising that up until very recently, many researchers focused more on "one bug one drug," rather than trying to target multiple viruses given those similarities. This attitude is now changing due to the realization that we need to be proactive rather than reactive when it comes to combating emerging and reemerging infectious diseases. A brief summary of prominent nucleoside analogues that previously exhibited broad-spectrum activity and are now under renewed interest, as well as new analogues, that are currently under investigation against SARS-CoV-2 and other viruses is discussed herein.
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Yu ZJ, Mosher EP, Bumpus NN. Pharmacogenomics of Antiretroviral Drug Metabolism and Transport. Annu Rev Pharmacol Toxicol 2020; 61:565-585. [PMID: 32960701 DOI: 10.1146/annurev-pharmtox-021320-111248] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Antiretroviral therapy has markedly reduced morbidity and mortality for persons living with human immunodeficiency virus (HIV). Individual tailoring of antiretroviral regimens has the potential to further improve the long-term management of HIV through the mitigation of treatment failure and drug-induced toxicities. While the mechanisms underlying anti-HIV drug adverse outcomes are multifactorial, the application of drug-specific pharmacogenomic knowledge is required in order to move toward the personalization of HIV therapy. Thus, detailed understanding of the metabolism and transport of antiretrovirals and the influence of genetics on these pathways is important. To this end, this review provides an up-to-date overview of the metabolism of anti-HIV therapeutics and the impact of genetic variation in drug metabolism and transport on the treatment of HIV. Future perspectives on and current challenges in pursuing personalized HIV treatment are also discussed.
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Affiliation(s)
- Zaikuan J Yu
- Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA;
| | - Eric P Mosher
- Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA;
| | - Namandjé N Bumpus
- Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA;
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Shahabadi N, Moshtkoob A. In vitro interaction of nucleoside reverse transcriptase inhibitor, didanosine with calf-thymus DNA: Insights from spectroscopic studies. NUCLEOSIDES NUCLEOTIDES & NUCLEIC ACIDS 2020; 39:1122-1133. [PMID: 32643522 DOI: 10.1080/15257770.2020.1780435] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Many antivirals interact with DNA and alter their expression profile. Thus, it is necessary to understand the binding mode. Didanosine, a nucleoside reverse transcriptase inhibitor, is used to treat HIV infection in patients with or without acquired immunodeficiency syndrome. Understanding the mechanism of interaction of this nucleoside reverse transcriptase inhibitor with DNA can prove useful in the development of a rational drug designing system. In vitro studies (UV-vis, fluorescence, and viscometry techniques) under physiological conditions (Tris-HCl buffer solutions, pH 7.4) show that didanosine drug interacts with calf-thymus DNA (ct-DNA) via partial intercalative binding mode. UV-visible spectroscopy confirmed the formation didanosine-DNA complex with a binding strength of about 1.5 × 105 M-1 thus indicating their biological worth. Dye displace experiments and viscometry confirmed that didanosine partially intercalates toward DNA molecules. Negative value of Gibb's-free energy change revealed that the process is spontaneous. The thermodynamic parameters such as enthalpy change (ΔH) and entropy change (ΔS) showed that the acting forces between didanosine and ct-DNA mainly included hydrophobic interactions.
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Affiliation(s)
- Nahid Shahabadi
- Department of Inorganic Chemistry, Faculty of Chemistry, Razi University, Kermanshah, Iran.,Medical Biology Research Center (MBRC), Kermanshah University of Medical Sciences, Kermanshah, Iran
| | - Ayda Moshtkoob
- Department of Inorganic Chemistry, Faculty of Chemistry, Razi University, Kermanshah, Iran
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11
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Xiao D, Ling KHJ, Tarnowski T, Majeed SR, Kearney B, Kolaris C, Zondlo S. The determination of human peripheral blood mononuclear cell counts using a genomic DNA standard and application in tenofovir diphosphate quantitation. Anal Biochem 2019; 585:113399. [PMID: 31437427 DOI: 10.1016/j.ab.2019.113399] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2019] [Revised: 08/13/2019] [Accepted: 08/14/2019] [Indexed: 10/26/2022]
Abstract
A fluorescent quantitation method to determine PBMC-derived DNA amounts using purified human genomic DNA (gDNA) as the reference standard was developed and validated. gDNA was measured in a fluorescence-based assay using a DNA intercalant, SYBR green. The fluorescence signal was proportional to the amount (mass) of DNA in the sample. The results confirmed a linear fit from 0.0665 to 1.17 μg/μL for gDNA, corresponding to 2.0 × 106 to 35.0 × 106 cells/PBMC sample. Intra-batch and inter-batch accuracy (%RE) was within ±15%, and precision (%CV) was <15%. Benchtop stability, freeze/thaw stability and long term storage stability of gDNA in QC sample matrix, PBMC pellets samples, and pellet debris samples, respectively, as well as dilution linearity had been established. Consistency between hemocytometry cell counting method and gDNA-based counting method was established. 6 out of 6 evaluated PBMC lots had hemocytometry cell counts that were within ±20% of the cell counts determined by the gDNA method. This method was used in conjunction with a validated LC-MS/MS method to determine the level of tenofovir diphosphate (TFV-DP), the active intracellular metabolite of the prodrugs tenofovir alafenamide (TAF) and tenofovir disoproxil fumarate (TDF), measured in PBMCs in clinical trials of TAF or TDF-containing fixed dose combinations.
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12
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Direct and indirect quantification of phosphate metabolites of nucleoside analogs in biological samples. J Pharm Biomed Anal 2019; 178:112902. [PMID: 31610397 DOI: 10.1016/j.jpba.2019.112902] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Revised: 08/22/2019] [Accepted: 09/29/2019] [Indexed: 12/19/2022]
Abstract
Nucleoside reverse transcriptase inhibitors (NRTIs) are prodrugs that require intracellular phosphorylation to active triphosphate nucleotide metabolites (NMs) for their pharmacological activity. However, monitoring these pharmacologically active NMs is challenging due to their instability, high hydrophilicity, and their low concentrations in blood and tissues. Liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) is the gold standard technique for the quantification of NRTIs and their phosphorylated NMs. In this review, an overview of the publications describing the quantitative analysis of intracellular and total tissue concentration of NMs is presented. The focus of this review is the comparison of the different approaches and challenges associated with sample collection, tissue homogenization, cell lysis, cell counting, analyte extraction, sample storage conditions, and LC-MS analysis. Quantification methods of NMs via LC-MS can be categorized into direct and indirect methods. In the direct LC-MS methods, chromatographic retention of the NMs is accomplished by ion-exchange (IEX), ion-pairing (IP), hydrophilic interaction (HILIC), porous graphitic carbon (PGC) chromatography, or capillary electrophoresis (CE). In indirect methods, parent nucleosides are 1st generated from the dephosphorylation of NMs during sample preparation and are then quantified by reverse phase LC-MS as surrogates for their corresponding NMs. Both approaches have advantages and disadvantages associated with them, which are discussed in this review.
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Shahabadi N, Abbasi AR, Moshtkob A, Hadidi S. Design, synthesis and DNA interaction studies of new fluorescent platinum complex containing anti-HIV drug didanosine. J Biomol Struct Dyn 2019; 38:2837-2848. [DOI: 10.1080/07391102.2019.1658643] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Affiliation(s)
- Nahid Shahabadi
- Department of Inorganic Chemistry, Faculty of Chemistry, Razi University, Kermanshah, Iran
- Medical Biology Research Center (MBRC), Kermanshah University of Medical Sciences, Kermanshah, Iran
| | - Amir Reza Abbasi
- Department of Inorganic Chemistry, Faculty of Chemistry, Razi University, Kermanshah, Iran
- Institute of Nano Science and Nano Technology, Razi University, Kermanshah, Iran
| | - Ayda Moshtkob
- Department of Inorganic Chemistry, Faculty of Chemistry, Razi University, Kermanshah, Iran
| | - Saba Hadidi
- Department of Inorganic Chemistry, Faculty of Chemistry, Razi University, Kermanshah, Iran
- Medical Biology Research Center (MBRC), Kermanshah University of Medical Sciences, Kermanshah, Iran
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Krawczyk H. The stilbene derivatives, nucleosides, and nucleosides modified by stilbene derivatives. Bioorg Chem 2019; 90:103073. [PMID: 31234131 DOI: 10.1016/j.bioorg.2019.103073] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Revised: 04/23/2019] [Accepted: 06/15/2019] [Indexed: 12/31/2022]
Abstract
In this short review, including 187 references, the issues of biological activity of stilbene derivatives and nucleosides and the biological and medicinal potential of fusion of these two classes are discussed. The stilbenes, especially the stilbenoids, and nucleosides are both biologically active. Hybrids formed from binding of these compounds have not yet been broadly studied. However, those that have been investigated exhibit desirable medicinal properties. The review is divided in such parts: I. Derivative of stilbene (biomedical investigations, biological activities in cells, enzymes and hazard), parts II. naturally occurred nucleoside and its derivatives: uridine, thymidine and 5-methyluridine, cytidine, adenosine, guanosine and part III. hybrid molecules- drugs and hybrid molecules- nucleoside - stilbene and its derivative.
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Affiliation(s)
- Hanna Krawczyk
- Department of Organic Chemistry, Faculty of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00-664 Warsaw, Poland.
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Jadav T, Jain S, Kalia K, Sengupta P. Current Standing and Technical Guidance on Intracellular Drug Quantification: A New Site Specific Bioavailability Prediction Approach. Crit Rev Anal Chem 2019; 50:50-61. [DOI: 10.1080/10408347.2019.1570462] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Affiliation(s)
- Tarang Jadav
- Department of Pharmaceutical Analysis, National Institute of Pharmaceutical Education and Research (NIPER), Ahmedabad, Gujarat, India
| | - Sonali Jain
- Department of Pharmaceutical Analysis, National Institute of Pharmaceutical Education and Research (NIPER), Ahmedabad, Gujarat, India
| | - Kiran Kalia
- Department of Biotechnology, National Institute of Pharmaceutical Education and Research (NIPER), Ahmedabad, Gujarat, India
| | - Pinaki Sengupta
- Department of Pharmaceutical Analysis, National Institute of Pharmaceutical Education and Research (NIPER), Ahmedabad, Gujarat, India
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Xiao D, Ling KHJ, Custodio J, Majeed SR, Tarnowski T. Quantitation of intracellular triphosphate metabolites of antiretroviral agents in peripheral blood mononuclear cells (PBMCs) and corresponding cell count determinations: review of current methods and challenges. Expert Opin Drug Metab Toxicol 2018; 14:781-802. [DOI: 10.1080/17425255.2018.1500552] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- Deqing Xiao
- Department of Clinical Pharmacology, Gilead Sciences, Inc, Foster City, CA, USA
| | - Kah Hiing John Ling
- Department of Clinical Pharmacology, Gilead Sciences, Inc, Foster City, CA, USA
| | - Joseph Custodio
- Department of Clinical Pharmacology, Gilead Sciences, Inc, Foster City, CA, USA
| | - Sophia R. Majeed
- Department of Clinical Pharmacology, Gilead Sciences, Inc, Foster City, CA, USA
| | - Thomas Tarnowski
- Department of Clinical Pharmacology, Gilead Sciences, Inc, Foster City, CA, USA
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17
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Ouyang B, Zhou F, Zhen L, Peng Y, Sun J, Chen Q, Jin X, Wang G, Zhang J. Simultaneous determination of tenofovir alafenamide and its active metabolites tenofovir and tenofovir diphosphate in HBV-infected hepatocyte with a sensitive LC-MS/MS method. J Pharm Biomed Anal 2017; 146:147-153. [PMID: 28881311 DOI: 10.1016/j.jpba.2017.08.028] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2017] [Revised: 08/14/2017] [Accepted: 08/18/2017] [Indexed: 11/30/2022]
Abstract
Tenofovir (TFV), a first-line anti-viral agent, has been prepared as various forms of prodrugs for better bioavailability, lower systemic exposure and higher target cells loading of TFV to enhance efficacy and reduce toxicity. TFV undergoes intracellular phosphorylation to form TFV diphosphate (TFV-DP) in target cell to inhibit viral DNA replication. Hence, TFV-DP is the key active metabolite that exhibits anti-virus activity, its intracellular exposure and half-life determine the final activity. Therefore, simultaneous monitoring prodrug, TFV and TFV-DP in target cells will comprehensively evaluate TFV prodrugs, both considering the stability of ester prodrug, and the intracellular exposure of TFV-DP. Thus we intended to develop a convenient general analytical method, taking tenofovir alafenamide (TAF) as a representative of TFV prodrugs. A sensitive LC-MS/MS method was developed, and TAF, TFV and TFV-DP were separated on a XSelect HSS T3 column (4.6mm×150mm, 3.5μm, Waters) with gradient elution after protein precipitation. The method provided good linearity for all the compounds (2-500nM for TFV and TAF; 20-5000nM for TFV-DP) with the correlation coefficients (r) greater than 0.999. Intra- and inter-day accuracies (in terms of relative error, RE<10.4%) and precisions (in terms of coefficient of variation, CV<14.1%) satisfied the standard of validation. The matrix effect, recovery and stability were also within acceptable criteria. Finally, we investigated the intracellular pharmacokinetics of TAF and its active metabolites in HepG2.2.15 cells with this method.
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Affiliation(s)
- Bingchen Ouyang
- Key Lab of Drug Metabolism and Pharmacokinetics, State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, Jiangsu, China
| | - Fang Zhou
- Key Lab of Drug Metabolism and Pharmacokinetics, State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, Jiangsu, China
| | - Le Zhen
- Key Lab of Drug Metabolism and Pharmacokinetics, State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, Jiangsu, China
| | - Ying Peng
- Key Lab of Drug Metabolism and Pharmacokinetics, State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, Jiangsu, China
| | - Jianguo Sun
- Key Lab of Drug Metabolism and Pharmacokinetics, State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, Jiangsu, China
| | - Qianying Chen
- Key Lab of Drug Metabolism and Pharmacokinetics, State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, Jiangsu, China
| | - Xiaoliang Jin
- Key Lab of Drug Metabolism and Pharmacokinetics, State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, Jiangsu, China
| | - Guangji Wang
- Key Lab of Drug Metabolism and Pharmacokinetics, State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, Jiangsu, China.
| | - Jingwei Zhang
- Key Lab of Drug Metabolism and Pharmacokinetics, State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, Jiangsu, China.
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Billat PA, Saint-Marcoux F. Liquid chromatography–mass spectrometry methods for the intracellular determination of drugs and their metabolites: a focus on antiviral drugs. Anal Bioanal Chem 2017; 409:5837-5853. [DOI: 10.1007/s00216-017-0449-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Revised: 05/24/2017] [Accepted: 06/01/2017] [Indexed: 01/11/2023]
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Ordonez P, Kunzelmann S, Groom HCT, Yap MW, Weising S, Meier C, Bishop KN, Taylor IA, Stoye JP. SAMHD1 enhances nucleoside-analogue efficacy against HIV-1 in myeloid cells. Sci Rep 2017; 7:42824. [PMID: 28220857 PMCID: PMC5318888 DOI: 10.1038/srep42824] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2016] [Accepted: 01/16/2017] [Indexed: 11/17/2022] Open
Abstract
SAMHD1 is an intracellular enzyme that specifically degrades deoxynucleoside triphosphates into component nucleoside and inorganic triphosphate. In myeloid-derived dendritic cells and macrophages as well as resting T-cells, SAMHD1 blocks HIV-1 infection through this dNTP triphosphohydrolase activity by reducing the cellular dNTP pool to a level that cannot support productive reverse transcription. We now show that, in addition to this direct effect on virus replication, manipulating cellular SAMHD1 activity can significantly enhance or decrease the anti-HIV-1 efficacy of nucleotide analogue reverse transcription inhibitors presumably as a result of modulating dNTP pools that compete for recruitment by viral polymerases. Further, a variety of other nucleotide-based analogues, not normally considered antiretrovirals, such as the anti-herpes drugs Aciclovir and Ganciclovir and the anti-cancer drug Clofarabine are now revealed as potent anti-HIV-1 agents, under conditions of low dNTPs. This in turn suggests novel uses for nucleotide analogues to inhibit HIV-1 in differentiated cells low in dNTPs.
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Affiliation(s)
- Paula Ordonez
- Retrovirus-Host Interactions Laboratory, The Francis Crick Institute, London, UK
| | - Simone Kunzelmann
- Structural Biology Science Technology Platform, The Francis Crick Institute, London, UK
| | - Harriet C. T. Groom
- Infection and Replication of Retroviruses Laboratory, The Francis Crick Institute, London, UK
| | - Melvyn W. Yap
- Retrovirus-Host Interactions Laboratory, The Francis Crick Institute, London, UK
| | - Simon Weising
- Organic Chemistry, Department of Chemistry, Faculty of Sciences, University of Hamburg, Germany
| | - Chris Meier
- Organic Chemistry, Department of Chemistry, Faculty of Sciences, University of Hamburg, Germany
| | - Kate N. Bishop
- Infection and Replication of Retroviruses Laboratory, The Francis Crick Institute, London, UK
| | - Ian A. Taylor
- Macromolecular Structure Laboratory, The Francis Crick Institute, London, UK
| | - Jonathan P. Stoye
- Retrovirus-Host Interactions Laboratory, The Francis Crick Institute, London, UK
- Faculty of Medicine, Imperial College London, London, UK
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Stray KM, Park Y, Babusis D, Callebaut C, Cihlar T, Ray AS, Perron M. Tenofovir alafenamide (TAF) does not deplete mitochondrial DNA in human T-cell lines at intracellular concentrations exceeding clinically relevant drug exposures. Antiviral Res 2017; 140:116-120. [PMID: 28131805 DOI: 10.1016/j.antiviral.2017.01.014] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2016] [Accepted: 01/22/2017] [Indexed: 12/01/2022]
Abstract
HIV-infected patients treated with certain nucleoside reverse transcriptase inhibitors (NRTIs) have experienced adverse effects due to drug-related mitochondrial toxicity. Tenofovir alafenamide (TAF) is a novel prodrug of the NRTI tenofovir (TFV) with an improved safety profile compared to tenofovir disoproxil fumarate (TDF). Prior in vitro studies have demonstrated that the parent nucleotide TFV has no significant effects on mtDNA synthesis. This study investigated whether clinically relevant TAF and TDF exposures affect mtDNA content in human lymphocytes. First, activated or resting peripheral blood mononuclear cells (PBMCs), as well as MT-2 and Jurkat T-cell lines, were continuously treated with ddC for 10 days to establish their susceptibility to mtDNA depletion. PBMCs had low sensitivity to NRTI-mediated mtDNA depletion in vitro. In contrast, ddC treatment of rapidly dividing MT-2 and Jurkat cells resulted in a dose-dependent decrease in mtDNA. Therefore, these two T-cell lines were selected for evaluating TAF and TDF treatment effects. MT-2 and Jurkat cells were pulse-treated with TAF or TDF every 24 h for 10 days to mimic pharmacologically relevant drug exposures. Pulse treatment of cells with 3.3 μM TAF or 1.1 μM TDF for 10 days resulted in 2- to 7-fold greater steady-state intracellular TFV-diphosphate (TFV-DP) levels than those observed clinically in TAF- or TDF-treated patients. At these concentrations, no significant TAF- (106.7% and 84.1% of control; p = 0.77 and 0.12 for MT-2 and Jurkat, respectively) or TDF- (100.6% and 91.0% of control; p = 0.91 and 0.37, respectively) associated reduction in mtDNA content was observed compared with untreated control cells. This study demonstrates that, despite delivering higher intracellular levels of TFV-DP than TDF, TAF does not inhibit mtDNA synthesis in vitro at concentrations exceeding the clinically relevant intracellular drug exposures. Thus, TAF has a low potential for mitochondrial toxicity in T-cells of HIV-infected patients.
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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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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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Hendrix CW, Andrade A, Bumpus NN, Kashuba AD, Marzinke MA, Moore A, Anderson PL, Bushman LR, Fuchs EJ, Wiggins I, Radebaugh C, Prince HA, Bakshi RP, Wang R, Richardson P, Shieh E, McKinstry L, Li X, Donnell D, Elharrar V, Mayer KH, Patterson KB. Dose Frequency Ranging Pharmacokinetic Study of Tenofovir-Emtricitabine After Directly Observed Dosing in Healthy Volunteers to Establish Adherence Benchmarks (HPTN 066). AIDS Res Hum Retroviruses 2016; 32:32-43. [PMID: 26414912 PMCID: PMC4692123 DOI: 10.1089/aid.2015.0182] [Citation(s) in RCA: 146] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Oral preexposure prophylaxis (PrEP) trials report disparate efficacy attributed to variable adherence. HPTN 066 was conducted to establish objective, quantitative benchmarks for discrete, regular levels of adherence using directly observed dosing of tenofovir (TFV) disoproxil fumarate (TDF)/emtricitabine (FTC). Healthy, HIV-uninfected men and women were randomized to one of four oral regimens of fixed-dose TDF 300 mg/FTC 200 mg tablet for 5 weeks with all doses observed: one tablet weekly (one/week), one tablet twice weekly (two/week), two tablets twice weekly (four/week), or one tablet daily (seven/week). Trough serum TFV and FTC, peripheral blood mononuclear cell (PBMC), and CD4(+) TFV-diphosphate (TFV-DP) and FTC-triphosphate (FTC-TP) concentrations were determined throughout dosing and 2 weeks after the last dose. Rectosigmoidal, semen, and cervicovaginal samples were collected for drug assessment at end of dosing and 2 weeks later in a subset of participants. The 49 enrolled participants tolerated the regimens well. All regimens achieved steady-state concentrations by the second dose for serum TFV/FTC and by 7 days for PBMC TFV-DP/FTC-TP. Steady-state median TFV-DP predose concentrations demonstrated dose proportionality: one/week 1.6 fmol/10(6) PBMCs, two/week 9.1, four/week 18.8, seven/week, 36.3. Further, TFV-DP was consistently quantifiable 2 weeks after the last dose for the ≥4/week regimens. Adherence benchmarks were identified using receiver operating characteristic curves, which had areas under the curve ≥0.93 for all analytes in serum and PBMCs. Intersubject and intrasubject coefficients of variation (%CV) ranged from 33% to 63% and 14% to 34%, respectively, for all analytes in serum and PBMCs. Steady-state PBMC TFV-DP was established earlier and at lower concentrations than predicted and was the only analyte demonstrating predose concentration dose proportionality. Steady-state daily dosing serum TFV and PBMC TFV-DP was consistent with highly effective PrEP clinical trials. HPTN 066 provides adherence benchmarks for oral TFV/FTC regimens to assist interpreting study outcomes.
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Affiliation(s)
| | | | | | - Angela D. Kashuba
- University of North Carolina-Chapel Hill, Chapel Hill, North Carolina
| | | | | | | | | | | | | | | | - Heather A. Prince
- University of North Carolina-Chapel Hill, Chapel Hill, North Carolina
| | | | - Ruili Wang
- University of North Carolina-Chapel Hill, Chapel Hill, North Carolina
| | | | | | | | - Xin Li
- SCHARP, Seattle, Washington
| | | | - Vanessa Elharrar
- National Institutes of Health Division of AIDS, Rockville, Maryland
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Ray AS, Fordyce MW, Hitchcock MJ. Tenofovir alafenamide: A novel prodrug of tenofovir for the treatment of Human Immunodeficiency Virus. Antiviral Res 2016; 125:63-70. [DOI: 10.1016/j.antiviral.2015.11.009] [Citation(s) in RCA: 207] [Impact Index Per Article: 25.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2015] [Revised: 11/20/2015] [Accepted: 11/23/2015] [Indexed: 10/22/2022]
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Simultaneous determination of 2',3'-dideoxyinosine and the active metabolite, 2',3'-dideoxyadenosine-5'-triphosphate in human peripheral-blood mononuclear cell by HPLC-MS/MS and the application to cell pharmacokinetics. J Chromatogr B Analyt Technol Biomed Life Sci 2015; 1002:337-42. [PMID: 26350426 DOI: 10.1016/j.jchromb.2015.08.039] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2015] [Revised: 08/24/2015] [Accepted: 08/26/2015] [Indexed: 11/20/2022]
Abstract
A specific and reliable HPLC-MS/MS method was developed and validated for the simultaneous determination of 2',3'-dideoxyinosine (ddI) and the active metabolites, 2',3'-dideoxyadenosine-5'-triphosphate (ddA-TP) in human peripheral-blood mononuclear cell for the first time. The analytes were separated on a HILIC column (100mm×2.1mm, 1.7μm) and a triple-quadrupole mass spectrometry equipped with an electrospray ionization (ESI) source was used for detection. The cell homogenates sample was prepared by the solid phase extraction. The calibration curves were linear over a concentration range of 0.5-200.0ng/mL for ddI and 0.25-100.0ng/mL for ddA-TP. The intra-day and inter-day precision was less than 15% and the relative error (RE) were all within ±15%. The validated method was successfully applied to assess the disposition characteristics of ddI and support cell pharmacokinetics after the patients with AIDS were orally administrated with ddI and tenofovir disoproxyl fumarate (TDF).
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Pharmacokinetics and preliminary safety study of pod-intravaginal rings delivering antiretroviral combinations for HIV prophylaxis in a macaque model. Antimicrob Agents Chemother 2014; 58:5125-35. [PMID: 24936594 DOI: 10.1128/aac.02871-14] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Preexposure prophylaxis using oral regimens involving the HIV nucleoside reverse transcriptase inhibitors tenofovir disoproxil fumarate (TDF) and emtricitabine (FTC) demonstrated efficacy in three clinical trials. Adherence was determined to be a key parameter for success. Incorporation of the TDF-FTC combination into intravaginal rings (IVRs) for sustained mucosal delivery could increase product adherence and efficacy compared with those of oral and vaginal gel formulations. A novel pod-IVR technology capable of delivering multiple drugs is described; this constitutes the first report of an IVR delivering TDF and FTC, as well as a triple-combination IVR delivering TDF, FTC, and the entry inhibitor maraviroc (MVC). The pharmacokinetics and preliminary local safety of the two combination pod-IVRs were evaluated in the pig-tailed macaque model. The devices exhibited sustained release at controlled rates over the 28-day study period. Median steady-state drug levels in vaginal tissues in the TDF-FTC group were 30 μg g(-1) (tenofovir [TFV], in vivo hydrolysis product of TDF) and 500 μg g(-1) (FTC) and in the TDF-FTC-MVC group were 10 μg g(-1) (TFV), 150 μg g(-1) (FTC), and 20 μg g(-1) (MVC). No adverse events were observed, and there were no toxicological findings. Mild-to-moderate increases in inflammatory infiltrates were observed in the vaginal tissues of some animals in both the presence and the absence of the IVRs. The IVRs did not disturb the vaginal microbiota, and levels of proinflammatory cytokines remained stable throughout the study. Pod-IVR candidates based on the TDF-FTC combination have potential for the prevention of vaginal HIV acquisition and merit clinical investigation.
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Louissaint NA, Cao YJ, Skipper PL, Liberman RG, Tannenbaum SR, Nimmagadda S, Anderson JR, Everts S, Bakshi R, Fuchs EJ, Hendrix CW. Single dose pharmacokinetics of oral tenofovir in plasma, peripheral blood mononuclear cells, colonic tissue, and vaginal tissue. AIDS Res Hum Retroviruses 2013; 29:1443-50. [PMID: 23600365 DOI: 10.1089/aid.2013.0044] [Citation(s) in RCA: 125] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
HIV seroconversion outcomes in preexposure prophylaxis (PrEP) trials of oral tenofovir (TFV)-containing regimens are highly sensitive to drug concentration, yet less-than-daily dosing regimens are under study. Description of TFV and its active moiety, TFV diphosphate (TFV-DP), in blood, vaginal tissue, and colon tissue may guide the design and interpretation of PrEP clinical trials. Six healthy women were administered a single oral dose of 300 mg tenofovir disoproxil fumarate (TDF) and 4.3 mg (12.31 MBq, 333 μCi) (14)C-TDF slurry. Blood was collected every 4 h for the first 24 h, then at 4, 8, 11, and 15 days postdosing. Colonic and vaginal samples (tissue, total and CD4(+) cells, luminal fluid and cells) were collected 1, 8 and 15 days postdose. Samples were analyzed for TFV and TFV-DP. Plasma TFV demonstrated triphasic decay with terminal elimination half-life median [interquartile range (IQR)] 69 h (58-77). Peripheral blood mononuclear cell (PBMC) TFV-DP demonstrated biphasic peaks (median 12 h and 96 h) followed by a terminal 48 h (38-76) half-life; Cmax was 20 fmol/million cells (2-63). One day postdose, the TFV-DP paired colon:vaginal tissue concentration ratio was 1 or greater in all subjects' tissue homogenates, median 124 (range 1-281), but was not sustained. The ratio was lower and more variable in cells extracted from tissue. Among all sample types, TFV and TFV-DP half-life ranged from 23 to 139 h. PBMC TFV-DP rose slowly in the hours after dosing indicating that success with exposure-driven dosing regimens may be sensitive to timing of the dose prior to exposure. Colonic tissue homogenate TFV-DP concentrations were greater than in vaginal homogenate at 24 h, but not in cells extracted from tissue. These and the other pharmacokinetic findings will guide the interpretation and design of future PrEP trials.
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Affiliation(s)
| | | | - Paul L. Skipper
- Massachusetts Institute of Technology, Cambridge, Massachusetts
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Abstract
The impressive advances in antiretroviral (ARV) therapy of chronic human immunodeficiency virus (HIV) infections during the last decade and the availability of potent ARV drugs have fueled interest in using chemoprophylaxis as a novel HIV prevention strategy. Preexposure prophylaxis (PrEP) refers to the use of ARV drugs in HIV-negative persons to prevent HIV infection. The rationale for PrEP builds on the success of ARV prophylaxis in preventing mother-to-child transmission of HIV and on a large body of animal studies that show the efficacy of PrEP against mucosal and parenteral infection. We focus on oral administration of ARV drugs for prevention of HIV infection. Identifying an effective prophylactic pill that individuals can take outside the setting of sexual intercourse precludes the necessity to disclose such use to their partners, thereby empowering those who might not be in a position to negotiate with their partners. Several human clinical trials evaluating the efficacy of daily regimens of the HIV reverse-transcriptase (RT) inhibitors tenofovir disoproxil fumarate (TDF) or Truvada (TDF and emtricitabine [FTC]) are under way among high-risk populations. The results of one trial among men who have sex with men showed that daily Truvada was safe and effective, providing the first support for oral PrEP as a prevention strategy. Here we outline the preclinical and clinical research on oral PrEP, pharmacologic considerations, and future directions and challenges.
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Affiliation(s)
- Walid Heneine
- Laboratory Branch, Division of HIV/AIDS Prevention, National Center for HIV, Hepatitis, STD, and Prevention, Centers for Disease Control and Prevention, Atlanta, Georgia 30333, USA.
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Castillo-Mancilla JR, Zheng JH, Rower JE, Meditz A, Gardner EM, Predhomme J, Fernandez C, Langness J, Kiser JJ, Bushman LR, Anderson PL. Tenofovir, emtricitabine, and tenofovir diphosphate in dried blood spots for determining recent and cumulative drug exposure. AIDS Res Hum Retroviruses 2013; 29:384-90. [PMID: 22935078 DOI: 10.1089/aid.2012.0089] [Citation(s) in RCA: 253] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Tenofovir (TFV) disoproxil fumarate (TDF)±emtricitabine (FTC) are widely used for HIV treatment and chemoprophylaxis, but variable adherence may lead to suboptimal responses. Methods that quantify adherence would allow for interventions to improve treatment and prevention outcomes. Our objective was to characterize the pharmacokinetics of TFV-diphosphate (TFV-DP) and FTC-triphosphate (FTC-TP) in red blood cells (RBCs) and peripheral blood mononuclear cells (PBMCs); to extend the RBC analysis to dried blood spots (DBSs); and to model how RBC/DBS monitoring could inform recent and cumulative drug exposure/adherence. Blood samples were collected from 17 HIV-negative adults at 5 visits over a 30-day pharmacokinetics study of daily oral TDF/FTC. Dosing was discontinued on day 30 and blood was collected on days 35, 45, and 60 during the washout period. Plasma/RBCs/PBMCs/DBSs were all quantified by liquid chromatography/tandem mass spectrometry. DBSs were paired with RBCs and plasma for comparisons. The median (interquartile range) RBC TFV-DP half-life was 17.1 (15.7-20.2) versus 4.2 (3.7-5.2) days in PBMCs. At steady state, TFV-DP was 130 fmol/10(6) RBCs versus 98 fmol/10(6) PBMCs. FTC-TP was not quantifiable in most RBC samples. TFV-DP in RBCs versus DBSs yielded an r(2)=0.83. TFV-DP in DBSs was stable at -20°C. Simulations of TFV-DP in RBCs/DBSs, when dosed from one to seven times per week, demonstrated that each dose per week resulted in an average change of approximately 19 fmol/10(6) RBCs and 230 fmol/punch. TFV and FTC in plasma versus DBSs was defined by y=1.4x; r(2)=0.96 and y=0.8x; r(2)=0.99, respectively. We conclude that DBSs offer a convenient measure of recent (TFV/FTC) and cumulative (TFV-DP in RBCs) drug exposure with potential application to adherence monitoring.
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Affiliation(s)
- Jose R. Castillo-Mancilla
- Division of Infectious Diseases, School of Medicine, University of Colorado-Anschutz Medical Campus, Aurora, Colorado
| | - Jia-Hua Zheng
- Department of Pharmaceutical Sciences, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado-Anschutz Medical Campus, Aurora, Colorado
| | - Joseph E. Rower
- Department of Pharmaceutical Sciences, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado-Anschutz Medical Campus, Aurora, Colorado
| | - Amie Meditz
- Division of Infectious Diseases, School of Medicine, University of Colorado-Anschutz Medical Campus, Aurora, Colorado
| | - Edward M. Gardner
- Division of Infectious Diseases, School of Medicine, University of Colorado-Anschutz Medical Campus, Aurora, Colorado
| | - Julie Predhomme
- Department of Pharmaceutical Sciences, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado-Anschutz Medical Campus, Aurora, Colorado
| | - Caitlin Fernandez
- Department of Pharmaceutical Sciences, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado-Anschutz Medical Campus, Aurora, Colorado
| | - Jacob Langness
- Department of Pharmacy, University of Colorado Hospital, Aurora, Colorado
| | - Jennifer J. Kiser
- Department of Pharmaceutical Sciences, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado-Anschutz Medical Campus, Aurora, Colorado
| | - Lane R. Bushman
- Department of Pharmaceutical Sciences, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado-Anschutz Medical Campus, Aurora, Colorado
| | - Peter L. Anderson
- Department of Pharmaceutical Sciences, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado-Anschutz Medical Campus, Aurora, Colorado
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Nakasone T, Murakami T, Yamamoto N. Double oral administration of emtricitabine/tenofovir prior to virus exposure protects against highly pathogenic simian/human immunodeficiency virus infection in macaques. Jpn J Infect Dis 2012; 65:345-9. [PMID: 22814162 DOI: 10.7883/yoken.65.345] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
In the absence of any effective vaccine against human immunodeficiency virus (HIV), current anti-retroviral drugs may be suitable for pre-exposure prophylaxis (PrEP). Previous large clinical trials showed that PrEP reduced HIV infection in high-risk populations. Emtricitabine/tenofovir (FTC/TDF) may be a suitable agent for PrEP. FTC/TDF PrEP efficacy was evaluated using a highly pathogenic simian/human immunodeficiency virus (SHIV) in a non-human primate model of AIDS, the SHIV-KS661c/cynomolgus monkey model. Double oral administration of FTC/TDF (20/30 mg/kg), at 24 h and a few minutes prior to exposure, completely protected 2/3 monkeys from infection. Interestingly, a single oral administration 2 weeks before viral exposure moderately rescued CD4 cells, although the data did not reach statistical significance. These results are consistent with previous primate studies and with recent clinical data.
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Affiliation(s)
- Tadashi Nakasone
- AIDS Research Center, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku-ku, Tokyo, Japan. nakabone@nih.go.jp
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Radzio J, Aung W, Holder A, Martin A, Sweeney E, Mitchell J, Bachman S, Pau CP, Heneine W, García-Lerma JG. Prevention of vaginal SHIV transmission in macaques by a coitally-dependent Truvada regimen. PLoS One 2012; 7:e50632. [PMID: 23226529 PMCID: PMC3514231 DOI: 10.1371/journal.pone.0050632] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2012] [Accepted: 10/22/2012] [Indexed: 02/07/2023] Open
Abstract
Background Daily pre-exposure prophylaxis (PrEP) with Truvada (a combination of emtricitabine (FTC) and tenofovir (TFV) disoproxil fumarate (TDF)) is a novel HIV prevention strategy recently found to prevent HIV transmission in men who have sex with men and heterosexual couples. We previously showed that a coitally-dependent Truvada regimen protected macaques against rectal SHIV transmission. Here we examined FTC and tenofovir TFV exposure in vaginal tissues after oral dosing and assessed if peri-coital Truvada also protects macaques against vaginal SHIV infection. Methods The pharmacokinetic profile of emtricitabine (FTC) and tenofovir (TFV) was evaluated at first dose. FTC and TFV levels were measured in blood plasma, rectal, and vaginal secretions. Intracellular concentrations of FTC-triphosphate (FTC-TP) and TFV-diphosphate (TFV-DP) were measured in PBMCs, rectal tissues, and vaginal tissues. Efficacy of Truvada in preventing vaginal SHIV infection was assessed using a repeat-exposure vaginal SHIV transmission model consisting of weekly exposures to low doses of SHIV162p3. Six pigtail macaques with normal menstrual cycles received Truvada 24 h before and 2 h after each weekly virus exposure and six received placebo. Infection was monitored by serology and PCR amplification of SHIV RNA and DNA. Results As in humans, the concentration of FTC was higher than the concentration of TFV in vaginal secretions. Also as in humans, TFV levels in vaginal secretions were lower than in rectal secretions. Intracellular TFV-DP concentrations were also lower in vaginal tissues than in rectal tissues. Despite the low vaginal TFV exposure, all six treated macaques were protected from infection after 18 exposures or 4 full menstrual cycles. In contrast, all 6 control animals were infected. Conclusions We modeled a peri-coital regimen with two doses of Truvada and showed that it fully protected macaques from repeated SHIV exposures. Our results open the possibility for simplified PrEP regimens to prevent vaginal HIV transmission in women.
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Affiliation(s)
- Jessica Radzio
- Laboratory Branch, Division of HIV/AIDS Prevention, National Center for HIV, Hepatitis, STD, and Prevention, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
| | - Wutyi Aung
- Laboratory Branch, Division of HIV/AIDS Prevention, National Center for HIV, Hepatitis, STD, and Prevention, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
| | - Angela Holder
- Laboratory Branch, Division of HIV/AIDS Prevention, National Center for HIV, Hepatitis, STD, and Prevention, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
| | - Amy Martin
- Laboratory Branch, Division of HIV/AIDS Prevention, National Center for HIV, Hepatitis, STD, and Prevention, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
| | - Elizabeth Sweeney
- Laboratory Branch, Division of HIV/AIDS Prevention, National Center for HIV, Hepatitis, STD, and Prevention, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
| | - James Mitchell
- Laboratory Branch, Division of HIV/AIDS Prevention, National Center for HIV, Hepatitis, STD, and Prevention, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
| | - Shanon Bachman
- Laboratory Branch, Division of HIV/AIDS Prevention, National Center for HIV, Hepatitis, STD, and Prevention, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
| | - Chou-Pong Pau
- Laboratory Branch, Division of HIV/AIDS Prevention, National Center for HIV, Hepatitis, STD, and Prevention, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
| | - Walid Heneine
- Laboratory Branch, Division of HIV/AIDS Prevention, National Center for HIV, Hepatitis, STD, and Prevention, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
| | - J. Gerardo García-Lerma
- Laboratory Branch, Division of HIV/AIDS Prevention, National Center for HIV, Hepatitis, STD, and Prevention, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
- * E-mail:
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Abstract
PURPOSE OF REVIEW Pre-exposure prophylaxis (PrEP) clinical trial results using antiretrovirals can seem confusing, if not conflicting. We review recent antiretroviral pharmacokinetic studies to help explain PrEP trial results. RECENT FINDINGS Pharmacokinetic studies indicate that topical dosing, compared with oral dosing, achieves far higher colon and vaginal tissue drug concentrations, and far lower drug concentrations in blood. After oral dosing, higher tenofovir diphosphate concentrations are found in colon tissue than cervico-vaginal tissue, but the reverse is the case for emtricitabine triphosphate, although it does not persist as long. Vaginal dosing achieves measurable tenofovir concentrations in the rectum and vice versa. Within and among oral PrEP trials, increased drug concentration is associated with increased HIV protection, with drug concentration differences best explained by adherence, rather than pharmacokinetics. The poor level of protection in topical studies is not consistent with concentration-response in oral studies indicating unknown variables in need of further investigation. SUMMARY Sparse pharmacokinetic sampling in large trials combined with more intensive sampling in smaller pharmacokinetic-focused studies help explain trial outcome differences due largely to differences in adherence, tissue pharmacokinetics, and type of HIV exposure. Pharmacokinetic analysis can identify protective drug concentration targets, guide dose optimization, and inform future trials.
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Affiliation(s)
- Craig W Hendrix
- Division of Clinical Pharmacology, Department of Medicine, Johns Hopkins University, School of Medicine, Baltimore, Maryland, USA.
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Safety and pharmacokinetics of intravaginal rings delivering tenofovir in pig-tailed macaques. Antimicrob Agents Chemother 2012; 56:5952-60. [PMID: 22964245 DOI: 10.1128/aac.01198-12] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Antiretroviral-based microbicides applied topically to the vagina may play an important role in protecting women from HIV infection. Incorporation of the nucleoside reverse transcriptase inhibitor tenofovir (TFV) into intravaginal rings (IVRs) for sustained mucosal delivery may lead to increased microbicide product adherence and efficacy compared with those of conventional vaginal formulations. Formulations of a novel "pod IVR" platform spanning a range of IVR drug loadings and daily release rates of TFV were evaluated in a pig-tailed macaque model. The rings were safe and exhibited sustained release at controlled rates over 28 days. Vaginal secretion TFV levels were independent of IVR drug loading and were able to be varied over 1.5 log units by changing the ring configuration. Mean TFV levels in vaginal secretions were 72.4 ± 109 μg ml(-1) (slow releasing) and 1.84 ± 1.97 mg ml(-1) (fast releasing). The mean TFV vaginal tissue concentration from the slow-releasing IVRs was 76.4 ± 54.8 μg g(-1) and remained at steady state 7 days after IVR removal, consistent with the long intracellular half-life of TFV. Intracellular tenofovir diphosphate (TFV-DP), the active moiety in defining efficacy, was measured in vaginal lymphocytes collected in the study using the fast-releasing IVR formulation. Mean intracellular TFV-DP levels of 446 ± 150 fmol/10(6) cells fall within a range that may be protective of simian-human immunodeficiency virus strain SF162p3 (SHIV(SF162p3)) infection in nonhuman primates. These data suggest that TFV-releasing IVRs based on the pod design have potential for the prevention of transmission of human immunodeficiency virus type 1 (HIV-1) and merit further clinical investigation.
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Uglietti A, Zanaboni D, Gnarini M, Maserati R. Emtricitabine/tenofovir in the treatment of HIV infection: current PK/PD evaluation. Expert Opin Drug Metab Toxicol 2012; 8:1305-14. [PMID: 22943210 DOI: 10.1517/17425255.2012.714367] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
INTRODUCTION Emtricitabine/tenofovir disoproxil fumarate fixed-dose combination (FTC/TDF FDC) is the co-formulation of a nucleoside and a nucleotide, respectively. After oral administration, both drugs exhibit plasma and intracellular half-lives suitable for once-daily dosing. Within the host cells, active metabolites FTC-TP and TFV-DP act as chain terminators to the newly synthesized proviral DNA, showing synergy at enzymatic level (viral reverse transcriptase). When given in HAART combinations, FTC/TDF FDC has a remarkable effectiveness in controlling HIV replication and securing a significant CD4(+) cell recovery. If patients treated with FTC/TDF FDC fail, a lower incidence of TDF-associated K65R resistance mutation seems to develop. Furthermore, cytidine analog-associated M184V is less likely to appear with FTC than with lamivudine when both are given with TDF. FTC and TFV are not metabolized by CYP450 enzymes and are eliminated by the renal route. TFV may accumulate in tubular cells and cause a decrease in GFR and a loss of phosphates. As a onsequence, patients treated with FTC/TDF FCD may experience varied degrees of renal impairment and osteopenia/osteoporosis. AREAS COVERED This paper has focused on the PK/PD features of FTC and TDF, when given as single agent or when administered as FDC. The interpretation of efficacy/toxicity was guided by PK/PD features. The review of the available literature included also conference presentations and recent guidelines (as of May 2012). EXPERT OPINION FTC/TDF FDC is a potent and reliable component of most HAART combinations due to its maintained activity across time, as demonstrated in many trials and studies. Toxicity issues (kidney, bone) are still to be entirely elucidated and the drug-induced component well separated from patient- and HIV-related ones. However, the clinical gain associated with the use of FTC/TDF FDC is fully acknowledged by its leading position in most current treatment guidelines.
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Affiliation(s)
- Alessia Uglietti
- Infectious Disease Department, Foundation IRCCS Policlinico San Matteo, Piazzale Golgi, 19, 27100 Pavia, Italy
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Babusis D, Phan TK, Lee WA, Watkins WJ, Ray AS. Mechanism for Effective Lymphoid Cell and Tissue Loading Following Oral Administration of Nucleotide Prodrug GS-7340. Mol Pharm 2012; 10:459-66. [DOI: 10.1021/mp3002045] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Darius Babusis
- Gilead Sciences, Inc.,
Foster City, California 94404, United States
| | - Truc K. Phan
- Gilead Sciences, Inc.,
Foster City, California 94404, United States
| | - William A. Lee
- Gilead Sciences, Inc.,
Foster City, California 94404, United States
| | | | - Adrian S. Ray
- Gilead Sciences, Inc.,
Foster City, California 94404, United States
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Duwal S, Schütte C, von Kleist M. Pharmacokinetics and pharmacodynamics of the reverse transcriptase inhibitor tenofovir and prophylactic efficacy against HIV-1 infection. PLoS One 2012; 7:e40382. [PMID: 22808148 PMCID: PMC3394807 DOI: 10.1371/journal.pone.0040382] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2012] [Accepted: 06/05/2012] [Indexed: 11/18/2022] Open
Abstract
Antiviral pre-exposure prophylaxis (PrEP) through daily drug administration can protect healthy individuals from HIV-1 infection. While PrEP was recently approved by the FDA, the potential long-term consequences of PrEP implementation remain entirely unclear. The aim of this study is to predict the efficacy of different prophylactic strategies with the pro-drug tenofovir-disoproxil-fumarate (TDF) and to assess the sensitivity towards timing- and mode of TDF administration (daily- vs. single dose), adherence and the number of transmitted viruses. We developed a pharmacokinetic model for TDF and its active anabolite tenofovir-diphosphate (TFV-DP) and validated it with data from 4 different trials, including 4 distinct dosing regimes. Pharmacokinetics were coupled to an HIV model and viral decay following TDF mono-therapy was predicted, consistent with available data. Subsequently, a stochastic approach was used to estimate the % infections prevented by (i) daily TDF-based PrEP, (ii) one week TDF started either shortly before, or -after viral exposure and (iii) a single dose oral TDF before viral challenge (sd-PrEP). Analytical solutions were derived to assess the relation between intracellular TFV-DP concentrations and prophylactic efficacy. The predicted efficacy of TDF was limited by a slow accumulation of active compound (TFV-DP) and variable TFV-DP half-life and decreased with increasing numbers of transmitted viruses. Once daily TDF-based PrEP yielded [Formula: see text]80% protection, if at least 40% of pills were taken. Sd-PrEP with 300 mg or 600 mg TDF could prevent [Formula: see text]50% infections, when given at least before virus exposure. The efficacy dropped to [Formula: see text]10%, when given 1 h before 24 h exposure. Efficacy could not be increased with increasing dosage or prolonged administration. Post-exposure prophylaxis poorly prevented infection. The use of drugs that accumulate more rapidly, or local application of tenofovir gel may overcome the need for drug administration long before virus exposure.
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Affiliation(s)
- Sulav Duwal
- Department of Mathematics and Computer Science, Free University Berlin, Berlin, Germany
| | - Christof Schütte
- Department of Mathematics and Computer Science, Free University Berlin, Berlin, Germany
| | - Max von Kleist
- Department of Mathematics and Computer Science, Free University Berlin, Berlin, Germany
- * E-mail:
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Compared to subcutaneous tenofovir, oral tenofovir disoproxyl fumarate administration preferentially concentrates the drug into gut-associated lymphoid cells in simian immunodeficiency virus-infected macaques. Antimicrob Agents Chemother 2012; 56:4980-4. [PMID: 22777046 DOI: 10.1128/aac.01095-12] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
To compare tissue-based pharmacokinetics and efficacy of oral tenofovir disoproxyl fumarate (TDF) versus subcutaneous tenofovir (TFV), macaques were treated for 2 weeks starting 1 week after simian immunodeficiency virus inoculation. Despite lower plasma TFV levels in the oral TDF arm, similar TFV diphosphate levels and antiviral activities were measured in lymphoid cells of most tissues. In intestinal tissues, however, oral TDF resulted in higher active drug levels, associated with lower virus levels and better immune preservation.
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Nuttall J, Kashuba A, Wang R, White N, Allen P, Roberts J, Romano J. Pharmacokinetics of tenofovir following intravaginal and intrarectal administration of tenofovir gel to rhesus macaques. Antimicrob Agents Chemother 2012; 56:103-9. [PMID: 21986823 PMCID: PMC3256015 DOI: 10.1128/aac.00597-11] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2011] [Accepted: 09/29/2011] [Indexed: 11/20/2022] Open
Abstract
Tenofovir gel (1%) is being developed as a microbicide for the prevention of human immunodeficiency virus (HIV) infection and has been shown to reduce transmission to women by 39%. The gel also prevents infection in macaques when applied intravaginally or intrarectally prior to challenge with simian-human immunodeficiency virus (SHIV), but very little pharmacokinetic information for macaques is available to help extrapolate the data to humans and thus inform future development activities. We have determined the pharmacokinetics of tenofovir in macaques following intravaginal and intrarectal administration of 0.2, 1, and 5% gels. Plasma and vaginal and rectal fluid samples were collected up to 24 h after dosing, and at 24 h postdosing biopsy specimens were taken from the vaginal wall, cervix, and rectum. Following vaginal and rectal administration, tenofovir rapidly distributed to the matrices distal to the site of administration. In all matrices, exposure increased with increasing dose, and with the 1% and 5% formulations, concentrations remained detectable in most animals 24 h after dosing. At all doses, concentrations at the dosing site were typically 1 to 2 log units higher than those in the opposite compartment and 4 to 5 log units higher than those in plasma. Exposure in vaginal fluid after vaginal dosing was 58 to 82% lower than that in rectal fluid after rectal dosing, but plasma exposure was 1- to 2-fold greater after vaginal dosing than after rectal dosing. These data suggest that a tenofovir-based microbicide may have the potential to protect when exposure is via vaginal or anal intercourse, regardless of whether the microbicide is applied vaginally or rectally.
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Affiliation(s)
- Jeremy Nuttall
- International Partnership for Microbicides, Silver Spring, Maryland, USA.
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Plasma and intracellular population pharmacokinetic analysis of tenofovir in HIV-1-infected patients. Antimicrob Agents Chemother 2011; 55:5294-9. [PMID: 21896913 DOI: 10.1128/aac.05317-11] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The relationships among the dose of tenofovir disoproxil fumarate (TDF), tenofovir (TFV) plasma concentrations, and intracellular TFV diphosphate (TFV-DP) concentrations are poorly understood. Our objective was to characterize TFV and TFV-DP relationships. Data were pooled from two studies in HIV-infected persons (n = 55) on stable antiretroviral therapy. TFV and TFV-DP were measured with validated liquid chromatography/tandem mass spectrometry (LC/MS/MS) methods. Nonlinear mixed effects modeling (NONMEM 7) was used to develop the population model and explore the influence of covariates on TFV. A sequential analysis approach was utilized. A two-compartment model with first-order absorption best described TFV PK (FOCEI). An indirect stimulation of response model best described TFV-DP, where formation of TFV-DP was driven by plasma TFV concentration. Final plasma population estimates were as follows: absorption rate constant, 1.03 h(-1); apparent clearance (CL/F), 42 liters/h (33.5% interindividual variability [IIV]); intercompartment clearance, 181 liters/h; apparent central distribution volume (Vc/F), 273 liters (64.8% IIV); and apparent peripheral distribution volume (Vp/F), 440 liters (46.5% IIV). Creatinine clearance was the most significant covariate on CL/F and Vc/F. The correlation between CL/F and Vc/F was 0.553. The indirect response model for TFV-DP resulted in estimates of the maximal intracellular concentration (E(max)), the TFV concentration producing 50% of E(max) (EC(50)), and the intracellular elimination rate constant (k(out)) of 300 fmol/10(6) cells (82% IIV), 100 ng/ml (106% IIV), and 0.008 h(-1), respectively. The estimated k(out) gave an 87-h TFV-DP half-life. A predictive check assessment indicated satisfactory model performance. This model links formation of TFV-DP with plasma TFV concentrations and should facilitate more informed investigations of TFV clinical pharmacology.
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Pethö B. An intrinsic way of multiclassification of endogenous psychoses. A follow-through investigation/Budapest 2000/based upon Leonhard's classification. PSYCHIATRIE, NEUROLOGIE UND MEDIZINISCHE PSYCHOLOGIE. BEIHEFTE 2011; 27:669-80. [PMID: 3101085 DOI: 10.1089/aid.2010.0206] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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Haverkort ME, van der Spek BW, Lips P, Slieker WA, ter Heine R, Huitema AD, Bronsveld W. Tenofovir-induced Fanconi syndrome and osteomalacia in two HIV-infected patients: Role of intracellular tenofovir diphosphate levels and review of the literature. ACTA ACUST UNITED AC 2011; 43:821-6. [DOI: 10.3109/00365548.2011.577805] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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Natural substrate concentrations can modulate the prophylactic efficacy of nucleotide HIV reverse transcriptase inhibitors. J Virol 2011; 85:6610-7. [PMID: 21525346 DOI: 10.1128/jvi.00311-11] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Preexposure prophylaxis (PrEP) with antiretroviral drugs is a novel human immunodeficiency virus (HIV) prevention strategy. It is generally thought that high systemic and mucosal drug levels are sufficient for protection. We investigated whether GS7340, a next-generation tenofovir (TFV) prodrug that effectively delivers tenofovir diphosphate (TFV-DP) to lymphoid cells and tissues, could protect macaques against repeated weekly rectal simian-human immunodeficiency virus (SHIV) exposures. Macaques received prophylactic GS7340 treatment 3 days prior to each virus exposure. At 3 days postdosing, TFV-DP concentrations in peripheral blood mononuclear cells (PBMCs) were about 50-fold higher than those seen with TFV disoproxil fumarate (TDF), and they remained above 1,000 fmol/10(6) cells for as long as 7 days. TFV-DP accumulated in lymphoid and rectal tissues, with concentrations at 3 days exceeding 500 fmol/10(6) mononuclear cells. Despite high mucosal and systemic TFV levels, GS7340 was not protective. Since TFV-DP blocks reverse transcription by competing with the natural dATP substrate, we measured dATP contents in peripheral lymphocytes, lymphoid tissue, and rectal mononuclear cells. Compared to those in circulating lymphocytes and lymphoid tissue, rectal lymphocytes had 100-fold higher dATP concentrations and dATP/TFV-DP ratios, likely reflecting the activated status of the cells and suggesting that TFV-DP may be less active at the rectal mucosa. Our results identify dATP/TFV-DP ratios as a possible correlate of protection by TFV and suggest that natural substrate concentrations at the mucosa will likely modulate the prophylactic efficacy of nucleotide reverse transcriptase inhibitors.
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Romanelli F, Murphy B. Systemic preexposure prophylaxis for human immunodeficiency virus infection. Pharmacotherapy 2011; 30:1021-30. [PMID: 20874040 DOI: 10.1592/phco.30.10.1021] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Antiretroviral therapy has significantly improved the typical course of human immunodeficiency virus (HIV) infection in industrialized nations, and life expectancies associated with the infection have increased. However, infection rates have generally remained unchanged, with increases noted among certain subpopulations. The use of systemic preexposure prophylaxis for HIV infection has been proposed as an intervention to reduce the risk of disease transmission in at-risk individuals. The basis of this prophylaxis involves the orchestrated use of antiretrovirals in uninfected individuals either continuously or just before high-risk situations, such as perinatal and occupational exposure to HIV, in order to reduce the likelihood of successful HIV infection. Data from the use of antiretrovirals to prevent HIV infection in these scenarios support the concept of preexposure prophylaxis. Preliminary animal studies have focused on the use of antiretrovirals to prevent simian immunodeficiency virus infection in macaque monkeys, and these data have provided support for the potential efficacy of preexposure prophylaxis for HIV in humans. Limited human data are available, however, but studies are ongoing. Clinical trials have focused on the use of tenofovir disoproxil fumarate either alone or in combination with emtricitabine. Tenofovir-emtricitabine-based regimens may be ideal, given the drugs' pharmacodynamic and pharmacokinetic properties. Some investigators have surveyed at-risk individuals to assess their knowledge of preexposure prophylaxis and whether they used or intended to use this prevention strategy. Routine use of preexposure prophylaxis and even knowledge of its existence appear to be very limited. If efficacy is proved, use of preexposure prophylaxis faces several ethical issues. Ultimately, its success will depend on proof of cost-effectiveness. Until the many questions concerning optimal use of preexposure prophylaxis for HIV are answered, however, its use should be limited to research-related clinical investigations.
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Affiliation(s)
- Frank Romanelli
- Colleges of Pharmacy, University of Kentucky, Lexington, Kentucky 40536, USA.
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Plasma and intracellular tenofovir pharmacokinetics in the neonate (ANRS 12109 trial, step 2). Antimicrob Agents Chemother 2011; 55:2961-7. [PMID: 21464249 DOI: 10.1128/aac.01377-10] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
The objective of this study was to investigate for the first time tenofovir (TFV) pharmacokinetics in plasma and peripheral blood mononuclear cells (PBMCs) of the neonate. HIV-1-infected pregnant women received two tablets of tenofovir disoproxil fumarate (TDF; 300 mg) and emtricitabine (FTC; 200 mg) at onset of labor and then one tablet daily for 7 days postpartum. A single dose of 13 mg/kg of body weight of TDF was administered to 36 neonates within 12 h of life after the HIV-1-infected mothers had been administered two tablets of TDF-emtricitabine at delivery. A total of 626 samples collected within the 2 days after the drug administration were measured by liquid chromatography-tandem mass spectrometry (LC-MS/MS) and analyzed by a population approach. In the neonate, the median TFV plasma area under the curve and minimal and maximal concentrations, respectively, were 3.73 mg/liter · h and 0.076 and 0.29 mg/liter. In PBMCs, TFV concentrations were detectable in all fetuses, whereas tenofovir diphosphate (TFV-DP) was quantifiable in only two fetuses, suggesting a lag in appearance of TFV-DP. The median TFV-DP neonatal concentration was 146 fmol/10⁶ cells (interquartile range [IQR], 53 to 430 fmol/10⁶ cells); two neonates had very high TFV-DP concentrations (1,530 and 2963 fmol/10⁶ cells). The 13-mg/kg TDF dose given to neonates produced plasma TFV and intracellular active TFV-DP concentrations similar to those in adults. This dose should be given immediately after birth to reduce the delay before the active compound TFV-DP appears in cells.
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Jansen RS, Rosing H, Schellens JHM, Beijnen JH. Mass spectrometry in the quantitative analysis of therapeutic intracellular nucleotide analogs. MASS SPECTROMETRY REVIEWS 2011; 30:321-343. [PMID: 20623700 DOI: 10.1002/mas.20280] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2009] [Accepted: 09/29/2009] [Indexed: 05/29/2023]
Abstract
Nucleoside analogs are widely used in anti-cancer, anti-(retro)viral, and immunosuppressive therapy. Nucleosides are prodrugs that require intracellular activation to mono-, di-, and finally triphosphates. Monitoring of these intracellular nucleotides is important to understand their pharmacology. The relatively involatile salts and ion-pairing agents traditionally used for the separation of these ionic analytes limit the applicability of mass spectrometry (MS) for detection. Both indirect and direct methods have been developed to circumvent this apparent incompatibility. Indirect methods consist of de-phosphorylation of the nucleotides into nucleosides before the actual analysis. Various direct approaches have been developed, ranging from the use of relatively volatile or very low levels of regular ion-pairing agents, hydrophilic interaction chromatography (HILIC), weak anion-exchange, or porous graphitic carbon columns to capillary electrophoresis and matrix-assisted light desorption--time of flight (MALDI-TOF) MS. In this review we present an overview of the publications describing the quantitative analysis of therapeutic intracellular nucleotide analogs using MS. The focus is on the different approaches for their direct analysis. We conclude that despite the technical hurdles, several useful MS-compatible chromatographic approaches have been developed, enabling the use of the excellent selectivity and sensitivity of MS for the quantitative analysis of intracellular nucleotides.
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Affiliation(s)
- Robert S Jansen
- Department of Pharmacy & Pharmacology, Slotervaart Hospital/The Netherlands Cancer Institute, Louwesweg 6, 1066 EC Amsterdam, The Netherlands.
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Anderson PL, Kiser JJ, Gardner EM, Rower JE, Meditz A, Grant RM. Pharmacological considerations for tenofovir and emtricitabine to prevent HIV infection. J Antimicrob Chemother 2011; 66:240-50. [PMID: 21118913 PMCID: PMC3019086 DOI: 10.1093/jac/dkq447] [Citation(s) in RCA: 139] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The use of antiretroviral medications in HIV-negative individuals as pre-exposure prophylaxis (PrEP) is a promising approach to prevent HIV infection. Tenofovir disoproxil fumarate (TDF) and emtricitabine exhibit desirable properties for PrEP including: favourable pharmacokinetics that support infrequent dosing; few major drug-drug or drug-food interactions; an excellent clinical safety record; and pre-clinical evidence for efficacy. Several large, randomized, controlled clinical trials are evaluating the safety and efficacy of TDF and emtricitabine for this new indication. A thorough understanding of variability in drug response will help determine future investigations in the field and/or implementation into clinical care. Because tenofovir and emtricitabine are nucleos(t)ide analogues, the HIV prevention and toxicity effects depend on the triphosphate analogue formed intracellularly. This review identifies important cellular pharmacology considerations for tenofovir and emtricitabine, which include drug penetration into relevant tissues and cell types, race/ethnicity/pharmacogenetics, gender, cellular activation state and appropriate episodic or alternative dosing strategies based on pharmacokinetic principles. The current state of knowledge in these areas is summarized and the future utility of intracellular pharmacokinetics/pharmacodynamics for the PrEP field is discussed.
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Affiliation(s)
- Peter L Anderson
- Department of Pharmaceutical Sciences, University of Colorado Denver, Aurora, CO, USA.
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Myers GM, Mayer KH. Oral preexposure anti-HIV prophylaxis for high-risk U.S. populations: current considerations in light of new findings. AIDS Patient Care STDS 2011; 25:63-71. [PMID: 21284497 DOI: 10.1089/apc.2010.0222] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
This article reviews the status of current research evaluating oral preexposure prophylaxis (PrEP) for prevention of HIV infection in high-risk populations. In animal model studies, the use of antiretrovirals has been shown to be effective in preventing HIV acquisition. Early-phase PrEP studies have established safety in humans. Currently, more than 20,000 men and women will soon be enrolled in studies of oral or topical chemoprophylaxis, testing a variety of drug delivery methods including tenofovir disoproxil fumarate (TDF) gel applied vaginally or rectally, as well as oral PrEP using TDF by itself or coformulated with emtricitabine (FTC). The largest global PrEP trial in men who have sex with men (MSM), known as iPrEx has demonstrated that oral chemoprophylaxis can decrease HIV incidence in this population. Although TDF/FTC PrEP was generally well tolerated, side effects such as nausea, as well as mild and reversible renal abnormalities were increased among the men who received active medication, suggesting that PrEP users will need ongoing PrEP clinical monitoring. The prophylactic benefits of TDF/FTC were substantially attenuated by nonadherence, indicating that effective PrEP implementation programs will need to focus on this behavioral variable, in addition to safer sex counseling. This article considers biological, policy, and practical implications of large-scale oral PrEP implementation.
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Affiliation(s)
- Gavin M. Myers
- Alpert Medical School of Brown University, Department of Community Health, Providence, Rhode Island
| | - Kenneth H. Mayer
- Alpert Medical School of Brown University, Department of Community Health, Providence, Rhode Island
- The Miriam Hospital, Providence, Rhode Island
- Fenway Institute, Boston, Massachusetts
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Intracellular nucleotide levels during coadministration of tenofovir disoproxil fumarate and didanosine in HIV-1-infected patients. Antimicrob Agents Chemother 2011; 55:1549-55. [PMID: 21282432 DOI: 10.1128/aac.00910-10] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Studies were conducted to determine if there is a mechanistic basis for reports of suboptimal virologic responses and concerns regarding the safety of regimens containing the combination of tenofovir (TFV) disoproxil fumarate (TDF) and didanosine (ddI) by assessing the pharmacokinetic consequences of coadministration of these drugs on intracellular nucleotides. This was a prospective and longitudinal study in HIV-1-infected patients of adding either TDF or ddI to a stable antiretroviral regimen containing the other drug. Intracellular concentrations of the nucleotide analogs TFV diphosphate (TFV-DP) and ddATP and the endogenous purine nucleotides dATP and 2'-dGTP in peripheral blood mononuclear cells were measured. A total of 16 patients were enrolled into the two study arms and a study extension. Intracellular TFV-DP concentrations (median, 120 fmol/10(6) cells) and ddATP concentrations (range, 1.50 to 7.54 fmol/10(6) cells in two patients) were unaffected following addition of ddI or TDF to a stable regimen containing the other drug. While coadministration of ddI and TDF for 4 weeks did not appear to impact dATP or dGTP concentrations, cross-sectional analysis suggested that extended therapy with ddI-containing regimens, irrespective of TDF coadministration, may decrease dATP and ddATP concentrations. Addition of TDF or ddI to a stable regimen including the other drug, in the context of ddI dose reduction, did not adversely affect the concentration of dATP, dGTP, TFV-DP, or ddATP. The association between longer-term ddI therapy and reduced intracellular nucleotide concentrations and this observation's implication for the efficacy and toxicity of ddI-containing regimens deserve further study.
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Pre-steady-state kinetic analysis of the incorporation of anti-HIV nucleotide analogs catalyzed by human X- and Y-family DNA polymerases. Antimicrob Agents Chemother 2010; 55:276-83. [PMID: 21078938 DOI: 10.1128/aac.01229-10] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Nucleoside reverse transcriptase inhibitors (NRTIs) are an important class of antiviral drugs used to manage infections by human immunodeficiency virus, which causes AIDS. Unfortunately, these drugs cause unwanted side effects, and the molecular basis of NRTI toxicity is not fully understood. Putative routes of NRTI toxicity include the inhibition of human nuclear and mitochondrial DNA polymerases. A strong correlation between mitochondrial toxicity and NRTI incorporation catalyzed by human mitochondrial DNA polymerase has been established both in vitro and in vivo. However, it remains to be determined whether NRTIs are substrates for the recently discovered human X- and Y-family DNA polymerases, which participate in DNA repair and DNA lesion bypass in vivo. Using pre-steady-state kinetic techniques, we measured the substrate specificity constants for human DNA polymerases β, λ, η, ι, κ, and Rev1 incorporating the active, 5'-phosphorylated forms of tenofovir, lamivudine, emtricitabine, and zidovudine. For the six enzymes, all of the drug analogs were incorporated less efficiently (40- to >110,000-fold) than the corresponding natural nucleotides, usually due to a weaker binding affinity and a slower rate of incorporation for the incoming nucleotide analog. In general, the 5'-triphosphate forms of lamivudine and zidovudine were better substrates than emtricitabine and tenofovir for the six human enzymes, although the substrate specificity profile depended on the DNA polymerase. Our kinetic results suggest NRTI insertion catalyzed by human X- and Y-family DNA polymerases is a potential mechanism of NRTI drug toxicity, and we have established a structure-function relationship for designing improved NRTIs.
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García-Lerma JG, Cong ME, Mitchell J, Youngpairoj AS, Zheng Q, Masciotra S, Martin A, Kuklenyik Z, Holder A, Lipscomb J, Pau CP, Barr JR, Hanson DL, Otten R, Paxton L, Folks TM, Heneine W. Intermittent prophylaxis with oral truvada protects macaques from rectal SHIV infection. Sci Transl Med 2010; 2:14ra4. [PMID: 20371467 DOI: 10.1126/scitranslmed.3000391] [Citation(s) in RCA: 139] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
HIV continues to spread globally, mainly through sexual contact. Despite advances in treatment and care, preventing transmission with vaccines or microbicides has proven difficult. A promising strategy to avoid transmission is prophylactic treatment with antiretroviral drugs before exposure to HIV. Clinical trials evaluating the efficacy of daily treatment with the reverse transcriptase inhibitors tenofovir disoproxil fumarate (TDF) or Truvada (TDF plus emtricitabine) are under way. We hypothesized that intermittent prophylactic treatment with long-acting antiviral drugs would be as effective as daily dosing in blocking the earliest stages of viral replication and preventing mucosal transmission. We tested this hypothesis by intermittently giving prophylactic Truvada to macaque monkeys and then exposing them rectally to simian-human immunodeficiency virus (SHIV) once a week for 14 weeks. A simple regimen with an oral dose of Truvada given 1, 3, or 7 days before exposure followed by a second dose 2 hours after exposure was as protective as daily drug administration, possibly because of the long intracellular persistence of the drugs. In addition, a two-dose regimen initiated 2 hours before or after virus exposure was effective, and full protection was obtained by doubling the Truvada concentration in both doses. We saw no protection if the first dose was delayed until 24 hours after exposure, underscoring the importance of blocking initial replication in the mucosa. Our results show that intermittent prophylactic treatment with an antiviral drug can be highly effective in preventing SHIV infection, with a wide window of protection. They strengthen the possibility of developing feasible, cost-effective strategies to prevent HIV transmission in humans.
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Affiliation(s)
- J Gerardo García-Lerma
- Division of HIV/AIDS Prevention, National Center for HIV, Hepatitis, STD, and Prevention, Centers for Disease Control and Prevention, 1600 Clifton Road, Atlanta, GA 30329, USA.
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