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Polasek TM, Peck RW. Beyond Population-Level Targets for Drug Concentrations: Precision Dosing Needs Individual-Level Targets that Include Superior Biomarkers of Drug Responses. Clin Pharmacol Ther 2024; 116:602-612. [PMID: 38328977 DOI: 10.1002/cpt.3197] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2023] [Accepted: 01/17/2024] [Indexed: 02/09/2024]
Abstract
The purpose of precision dosing is to increase the chances of therapeutic success in individual patients. This is achieved in practice by adjusting doses to reach precision dosing targets determined previously in relevant populations, ideally with robust supportive evidence showing improved clinical outcomes compared with standard dosing. But is this implicit assumption of translatable population-level precision dosing targets correct and the best for all patients? In this review, the types of precision dosing targets and how they are determined are outlined, problems with the translatability of these targets to individual patients are identified, and ways forward to address these challengers are proposed. Achieving improved clinical outcomes to support precision dosing over standard dosing is currently hampered by applying population-level targets to all patients. Just as "one-dose-fits-all" may be an inappropriate philosophy for drug treatment overall, a "one-target-fits-all" philosophy may limit the broad clinical benefits of precision dosing. Defining individual-level precision dosing targets may be needed for greatest therapeutic success. Superior future precision dosing targets will integrate several biomarkers that together account for the multiple sources of drug response variability.
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Affiliation(s)
- Thomas M Polasek
- Centre for Medicine Use and Safety, Monash University, Melbourne, Victoria, Australia
- CMAX Clinical Research, Adelaide, South Australia, Australia
| | - Richard W Peck
- Department of Pharmacology and Therapeutics, University of Liverpool, Liverpool, UK
- Pharma Research & Development (pRED), Roche Innovation Center Basel, Basel, Switzerland
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Widmer N, Guidi M, Buclin T. Population Pharmacokinetics in Oncology and Its Clinical Applications. Pharmaceutics 2024; 16:711. [PMID: 38931835 PMCID: PMC11207012 DOI: 10.3390/pharmaceutics16060711] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2024] [Accepted: 05/16/2024] [Indexed: 06/28/2024] Open
Abstract
Most traditional cytotoxic drugs are characterized by steep dose-response relationships and narrow therapeutic windows [...].
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Affiliation(s)
- Nicolas Widmer
- Service of Clinical Pharmacology, Lausanne University Hospital and University of Lausanne, 1011 Lausanne, Switzerland; (M.G.); (T.B.)
- Pharmacy of the Eastern Vaud Hospitals, 1847 Rennaz, Switzerland
- Institute of Pharmaceutical Sciences of Western Switzerland, University of Geneva, University of Lausanne, 1205 Geneva, Switzerland
| | - Monia Guidi
- Service of Clinical Pharmacology, Lausanne University Hospital and University of Lausanne, 1011 Lausanne, Switzerland; (M.G.); (T.B.)
- Institute of Pharmaceutical Sciences of Western Switzerland, University of Geneva, University of Lausanne, 1205 Geneva, Switzerland
- Center for Research and Innovation in Clinical Pharmaceutical Sciences, Lausanne University Hospital and University of Lausanne, 1011 Lausanne, Switzerland
| | - Thierry Buclin
- Service of Clinical Pharmacology, Lausanne University Hospital and University of Lausanne, 1011 Lausanne, Switzerland; (M.G.); (T.B.)
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Polasek TM. Pharmacogenomics - a minor rather than major force in clinical medicine. Expert Rev Clin Pharmacol 2024; 17:203-212. [PMID: 38307498 DOI: 10.1080/17512433.2024.2314726] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2023] [Accepted: 02/01/2024] [Indexed: 02/04/2024]
Abstract
INTRODUCTION Pharmacogenomics (PGx) is touted as essential for the future of precision medicine. But the opportunity cost of PGx from the prescribers' perspective is rarely considered. The aim of this article is to critique PGx-guided prescribing using clinical pharmacology principles so that important cases for PGx testing are not missed by doctors responsible for therapeutic decision making. AREAS COVERED Three categories of PGx and their limitations are outlined - exposure PGx, response PGx, and immune-mediated safety PGx. Clinical pharmacology reasons are given for the narrow scope of PGx-guided prescribing apart from a few medical specialties. Clinical problems for doctors that may arise from PGx are then explained, including mismatch between patients' expectations of PGx testing and the benefits or answers it provides. EXPERT OPINION Contrary to popular opinion, PGx is unlikely to become the cornerstone of precision medicine. Sound clinical pharmacology reasons explain why PGx-guided prescribing is unnecessary for most drugs. Pharmacogenomics is important for niche areas of prescribing but has limited clinical utility more broadly. The opportunity cost of PGx-guided prescribing is currently too great for most doctors.
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Affiliation(s)
- Thomas M Polasek
- Centre for Medicine Use and Safety, Monash University, Melbourne, Australia
- CMAX Clinical Research, Adelaide, Australia
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Dayal A, Pan JM, Kwan SP, Ackermann M, Khalil HA, Mentzer SJ. Facilitated Transport across Glycocalyceal Barriers in the Chick Chorioallantoic Membrane. Polymers (Basel) 2023; 16:4. [PMID: 38201668 PMCID: PMC10781099 DOI: 10.3390/polym16010004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2023] [Revised: 12/05/2023] [Accepted: 12/14/2023] [Indexed: 01/12/2024] Open
Abstract
Targeted drug delivery to visceral organs offers the possibility of not only limiting the required dose, but also minimizing drug toxicity; however, there is no reliable method for delivering drugs to the surface of visceral organs. Here, we used six color tracers and the chick chorioallantoic membrane (CAM) model to investigate the use of the heteropolysaccharide pectin to facilitate tracer diffusion across the glycocalyceal charge barrier. The color tracers included brilliant blue, Congo red, crystal violet, indocyanine green, methylene blue, and methyl green. The direct application of the tracers to the CAM surface or embedding tracers into linear-chain nanocellulose fiber films resulted in no significant diffusion into the CAM. In contrast, when the tracers were actively loaded into branched-chain pectin films, there was significant detectable diffusion of the tracers into the CAM. The facilitated diffusion was observed in the three cationic tracers but was limited in the three anionic tracers. Diffusion appeared to be dependent on ionic charge, but independent of tracer size or molecular mass. We conclude that dye-loaded pectin films facilitated the diffusion of color tracers across the glycocalyceal charge barrier and may provide a therapeutic path for drug delivery to the surface of visceral organs.
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Affiliation(s)
- Anuhya Dayal
- Laboratory of Adaptive and Regenerative Biology, Brigham & Women’s Hospital, Harvard Medical School, Boston, MA 02115, USA; (A.D.); (J.M.P.); (S.P.K.); (H.A.K.)
| | - Jennifer M. Pan
- Laboratory of Adaptive and Regenerative Biology, Brigham & Women’s Hospital, Harvard Medical School, Boston, MA 02115, USA; (A.D.); (J.M.P.); (S.P.K.); (H.A.K.)
| | - Stacey P. Kwan
- Laboratory of Adaptive and Regenerative Biology, Brigham & Women’s Hospital, Harvard Medical School, Boston, MA 02115, USA; (A.D.); (J.M.P.); (S.P.K.); (H.A.K.)
| | - Maximilian Ackermann
- Institute of Functional and Clinical Anatomy, University Medical Center, Johannes Gutenberg University, 55131 Mainz, Germany;
| | - Hassan A. Khalil
- Laboratory of Adaptive and Regenerative Biology, Brigham & Women’s Hospital, Harvard Medical School, Boston, MA 02115, USA; (A.D.); (J.M.P.); (S.P.K.); (H.A.K.)
| | - Steven J. Mentzer
- Laboratory of Adaptive and Regenerative Biology, Brigham & Women’s Hospital, Harvard Medical School, Boston, MA 02115, USA; (A.D.); (J.M.P.); (S.P.K.); (H.A.K.)
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Polasek TM. Virtual twin for healthcare management. Front Digit Health 2023; 5:1246659. [PMID: 37781454 PMCID: PMC10540783 DOI: 10.3389/fdgth.2023.1246659] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Accepted: 09/01/2023] [Indexed: 10/03/2023] Open
Abstract
Healthcare is increasingly fragmented, resulting in escalating costs, patient dissatisfaction, and sometimes adverse clinical outcomes. Strategies to decrease healthcare fragmentation are therefore attractive from payer and patient perspectives. In this commentary, a patient-centered smart phone application called Virtual Twin for Healthcare Management (VTHM) is proposed, including its organizational layout, basic functionality, and potential clinical applications. The platform features a virtual twin hub that displays the body and its health data. This is a physiologically based human model that is "virtualized" for the patient based on their unique genetic, molecular, physiological, and disease characteristics. The spokes of the system are a full service and interoperable electronic-health record, accessible to healthcare providers with permission on any device with internet access. Theoretical case studies based on real scenarios are presented to show how VTHM could potentially improve patient care and clinical efficiency. Challenges that must be overcome to turn VTHM into reality are also briefly outlined. Notably, the VTHM platform is designed to operationalize current and future precision medicine initiatives, such as access to molecular diagnostic results, pharmacogenomics-guided prescribing, and model-informed precision dosing.
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Affiliation(s)
- Thomas M. Polasek
- Certara, Princeton, NJ, United States
- Centre for Medicines Use and Safety, Monash University, Melbourne, VIC, Australia
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Active Loading of Pectin Hydrogels for Targeted Drug Delivery. Polymers (Basel) 2022; 15:polym15010092. [PMID: 36616442 PMCID: PMC9824191 DOI: 10.3390/polym15010092] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Revised: 12/09/2022] [Accepted: 12/13/2022] [Indexed: 12/28/2022] Open
Abstract
Hydrogels provide a promising method for the targeted delivery of protein drugs. Loading the protein drug into the hydrogel free volume can be challenging due to limited quantities of the drug (e.g., growth factor) and complex physicochemical properties of the hydrogel. Here, we investigated both passive and active loading of the heteropolysaccharide hydrogel pectin. Passive loading of glass phase pectin films was evaluated by contact angles and fractional thickness of the pectin films. Four pectin sources demonstrated mean contact angles of 88° with water and 122° with pleural fluid (p < 0.05). Slow kinetics and evaporative losses precluded passive loading. In contrast, active loading of the translucent pectin films was evaluated with the colorimetric tracer methylene blue. Active loading parameters were systematically varied and recorded at 500 points/s. The distribution of the tracer was evaluated by image morphometry. Active loading of the tracer into the pectin films required the optimization of probe velocity, compression force, and contact time. We conclude that active loading using pectin-specific conditions is required for the efficient embedding of low viscosity liquids into pectin hydrogels.
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Fahmy A, Hopkins AM, Sorich MJ, Rowland A. Evaluating the utility of therapeutic drug monitoring in the clinical use of small molecule kinase inhibitors: a review of the literature. Expert Opin Drug Metab Toxicol 2021; 17:803-821. [PMID: 34278936 DOI: 10.1080/17425255.2021.1943357] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Introduction: Orally administered small molecule kinase inhibitors (KI) are a key class of targeted anti-cancer medicines that have contributed substantially to improved survival outcomes in patients with advanced disease. Since the introduction of KIs in 2001, there has been a building body of evidence that the benefit derived from these drugs may be further enhanced by individualizing dosing on the basis of concentration.Areas covered: This review considers the rationale for individualized KI dosing and the requirements for robust therapeutic drug monitoring (TDM). Current evidence supporting TDM-guided KI dosing is presented and critically evaluated, and finally potential approaches to address translational challenges for TDM-guided KI dosing and alternate approaches to support individualization of KI dosing are discussed.Expert opinion: Intuitively, the individualization of KI dosing through an approach such as TDM-guided dosing has great potential to enhance the effectiveness and tolerability of these drugs. However, based on current literature evidence it is unrealistic to propose that TDM-guided KI dosing should be routinely implemented into clinical practice.
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Affiliation(s)
- Alia Fahmy
- College of Medicine and Public Health, Flinders University, Adelaide, SA, Australia
| | - Ashley M Hopkins
- College of Medicine and Public Health, Flinders University, Adelaide, SA, Australia
| | - Michael J Sorich
- College of Medicine and Public Health, Flinders University, Adelaide, SA, Australia
| | - Andrew Rowland
- College of Medicine and Public Health, Flinders University, Adelaide, SA, Australia
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Mechanistic Modelling Identifies and Addresses the Risks of Empiric Concentration-Guided Sorafenib Dosing. Pharmaceuticals (Basel) 2021; 14:ph14050389. [PMID: 33919091 PMCID: PMC8143107 DOI: 10.3390/ph14050389] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Revised: 04/14/2021] [Accepted: 04/19/2021] [Indexed: 12/12/2022] Open
Abstract
The primary objective of this study is to evaluate the capacity of concentration-guided sorafenib dosing protocols to increase the proportion of patients that achieve a sorafenib maximal concentration (Cmax) within the range 4.78 to 5.78 μg/mL. A full physiologically based pharmacokinetic model was built and validated using Simcyp® (version 19.1). The model was used to simulate sorafenib exposure in 1000 Sim-Cancer subjects over 14 days. The capacity of concentration-guided sorafenib dose adjustment, with/without model-informed dose selection (MIDS), to achieve a sorafenib Cmax within the range 4.78 to 5.78 μg/mL was evaluated in 500 Sim-Cancer subjects. A multivariable linear regression model incorporating hepatic cytochrome P450 (CYP) 3A4 abundance, albumin concentration, body mass index, body surface area, sex and weight provided robust prediction of steady-state sorafenib Cmax (R2 = 0.883; p < 0.001). These covariates identified subjects at risk of failing to achieve a sorafenib Cmax ≥ 4.78 μg/mL with 95.0% specificity and 95.2% sensitivity. Concentration-guided sorafenib dosing with MIDS achieved a sorafenib Cmax within the range 4.78 to 5.78 μg/mL for 38 of 52 patients who failed to achieve a Cmax ≥ 4.78 μg/mL with standard dosing. In a simulation setting, concentration-guided dosing with MIDS was the quickest and most effective approach to achieve a sorafenib Cmax within a designated range.
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Wen HN, Liu YX, Xu D, Zhao KJ, Jiao Z. Population pharmacokinetic modeling of pyrotinib in patients with HER2-positive advanced or metastatic breast cancer. Eur J Pharm Sci 2021; 159:105729. [PMID: 33484815 DOI: 10.1016/j.ejps.2021.105729] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Revised: 12/22/2020] [Accepted: 01/17/2021] [Indexed: 11/25/2022]
Abstract
OBJECTIVE Pyrotinib, a new oral irreversible pan-ErbB tyrosine kinase inhibitor (TKI), has been approved in China for the treatment of HER2-positive advanced or metastatic breast cancer. This study aimed to conduct a population pharmacokinetics (PK) analysis of pyrotinib and to evaluate the impact of patient characteristics on pyrotinib's PK. METHOD A total of 1152 samples, provided by 59 adult female patients from two phase I clinical trials, were analyzed by nonlinear mixed-effects modeling. Monte Carlo simulation was conducted to assess impact of covariates on the exposure to pyrotinib. RESULTS The PK of pyrotinib was adequately described by a one-compartment model with first-order absorption and elimination. Patient's age and total protein levels could affect pyrotinib's apparent volume of distribution, and concomitant use of montmorillonite could decrease the bioavailability of pyrotinib by 50.3%. No PK interactions were observed between capecitabine and pyrotinib. CONCLUSION In this study, a population PK model of pyrotinib was developed to determine the influence of patient characteristics on the PK of pyrotinib. While patient age and total protein levels can significantly affect the apparent distribution volume of pyrotinib, the magnitude of the impact was limited, thus no dosage adjustment was recommended. Furthermore, concomitant use of montmorillonite for diarrhea needs to be taken with precaution.
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Affiliation(s)
- Hai-Ni Wen
- Department of Pharmacy, Shanghai Chest Hospital, Shanghai Jiao Tong University, Shanghai, P.R. China
| | - Yi-Xi Liu
- Department of Pharmacy, Huashan Hospital, Fudan University, Shanghai, P.R. China
| | - Da Xu
- Department of Clinical Pharmacology, Jiangsu Hengrui Medicine Co. Ltd, Shanghai, P.R. China
| | - Kai-Jing Zhao
- Department of Clinical Pharmacology, Jiangsu Hengrui Medicine Co. Ltd, Shanghai, P.R. China
| | - Zheng Jiao
- Department of Pharmacy, Shanghai Chest Hospital, Shanghai Jiao Tong University, Shanghai, P.R. China.
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