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van de Velde ME, den Bakker E, Blufpand HN, Kaspers GL, Abbink FCH, Kors AWA, Wilhelm AJ, Honeywell RJ, Peters GJ, Stoffel-Wagner B, Buffart LM, Bökenkamp A. Carboplatin Dosing in Children Using Estimated Glomerular Filtration Rate: Equation Matters. Cancers (Basel) 2021; 13:cancers13235963. [PMID: 34885072 PMCID: PMC8656997 DOI: 10.3390/cancers13235963] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Revised: 11/17/2021] [Accepted: 11/19/2021] [Indexed: 11/16/2022] Open
Abstract
Renal function-based carboplatin dosing using measured glomerular filtration rate (GFR) results in more consistent drug exposure than anthropometric dosing. We aimed to validate the Newell dosing equation using estimated GFR (eGFR) and study which equation most accurately predicts carboplatin clearance in children with retinoblastoma. In 13 children with retinoblastoma 38 carboplatin clearance values were obtained from individual fits using MWPharm++. Carboplatin exposure (AUC) was calculated from administered dose and observed carboplatin clearance and compared to predicted AUC calculated with a carboplatin dosing equation (Newell) using different GFR estimates. Different dosing regimens were compared in terms of accuracy, bias and precision. All patients had normal eGFR. Carboplatin exposure using cystatin C-based eGFR equations tended to be more accurate compared to creatinine-based eGFR (30% accuracy 76.3-89.5% versus 76.3-78.9%, respectively), which led to significant overexposure, especially in younger (aged ≤ 2 years) children. Of all equations, the Schwartz cystatin C-based equation had the highest accuracy and lowest bias. Although anthropometric dosing performed comparably to many of the eGFR equations overall, we observed a weight-dependent change in bias leading to underdosing in the smallest patients. Using cystatin C-based eGFR equations for carboplatin dosing in children leads to more accurate carboplatin-exposure in patients with normal renal function compared to anthropometric dosing. In children with impaired kidney function, this trend might be more pronounced. Anthropometric dosing is hampered by a weight-dependent bias.
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Affiliation(s)
- Mirjam E. van de Velde
- Emma Children’s Hospital, Amsterdam UMC, Vrije Universiteit Amsterdam, Pediatric Oncology, 1081 HV Amsterdam, The Netherlands; (H.N.B.); (A.W.A.K.); (G.L.K.)
- Department of Pediatric Oncology/Hematology, Amsterdam UMC, 1081 HV Amsterdam, The Netherlands
- Correspondence: ; Tel.: +31-(0)20-444-6206; Fax: +31-(0)20-444-5122
| | - Emil den Bakker
- Emma Children’s Hospital, Amsterdam UMC, Vrije Universiteit Amsterdam, Pediatric Nephrology, 1081 HV Amsterdam, The Netherlands; (E.d.B.); (A.B.)
| | - Hester N. Blufpand
- Emma Children’s Hospital, Amsterdam UMC, Vrije Universiteit Amsterdam, Pediatric Oncology, 1081 HV Amsterdam, The Netherlands; (H.N.B.); (A.W.A.K.); (G.L.K.)
| | - Gertjan L. Kaspers
- Emma Children’s Hospital, Amsterdam UMC, Vrije Universiteit Amsterdam, Pediatric Oncology, 1081 HV Amsterdam, The Netherlands; (H.N.B.); (A.W.A.K.); (G.L.K.)
- Princess Máxima Center for Pediatric Oncology, 3584 CS Utrecht, The Netherlands
| | - Floor C. H. Abbink
- Emma Children’s Hospital, Amsterdam UMC, Amsterdam Medical Center, Pediatric Oncology, 1081 HV Amsterdam, The Netherlands;
| | - Arjenne W. A. Kors
- Emma Children’s Hospital, Amsterdam UMC, Vrije Universiteit Amsterdam, Pediatric Oncology, 1081 HV Amsterdam, The Netherlands; (H.N.B.); (A.W.A.K.); (G.L.K.)
- Princess Máxima Center for Pediatric Oncology, 3584 CS Utrecht, The Netherlands
| | - Abraham J. Wilhelm
- Amsterdam UMC, Vrije Universiteit Amsterdam, Clinical Pharmacology and Pharmacy, 1081 HV Amsterdam, The Netherlands;
| | - Richard J. Honeywell
- Laboratory of Medical Oncology, Amsterdam University Medical Center, VUMC, 1081 HV Amsterdam, The Netherlands; (R.J.H.); (G.J.P.)
| | - Godefridus J. Peters
- Laboratory of Medical Oncology, Amsterdam University Medical Center, VUMC, 1081 HV Amsterdam, The Netherlands; (R.J.H.); (G.J.P.)
- Department of Biochemistry, Medical University of Gdansk, 80-210 Gdansk, Poland
| | - Birgit Stoffel-Wagner
- Institute for Clinical Chemistry and Clinical Pharmacology, University of Bonn-Medical Center, 53127 Bonn, Germany;
| | - Laurien M. Buffart
- Department of Epidemiology and Biostatistics, Amsterdam UMC, Vrije Universiteit Amsterdam, 1081 HV Amsterdam, The Netherlands;
| | - Arend Bökenkamp
- Emma Children’s Hospital, Amsterdam UMC, Vrije Universiteit Amsterdam, Pediatric Nephrology, 1081 HV Amsterdam, The Netherlands; (E.d.B.); (A.B.)
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Abdulla A, Edwina EE, Flint RB, Allegaert K, Wildschut ED, Koch BCP, de Hoog M. Model-Informed Precision Dosing of Antibiotics in Pediatric Patients: A Narrative Review. Front Pediatr 2021; 9:624639. [PMID: 33708753 PMCID: PMC7940353 DOI: 10.3389/fped.2021.624639] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2020] [Accepted: 02/03/2021] [Indexed: 12/17/2022] Open
Abstract
Optimal pharmacotherapy in pediatric patients with suspected infections requires understanding and integration of relevant data on the antibiotic, bacterial pathogen, and patient characteristics. Because of age-related physiological maturation and non-maturational covariates (e.g., disease state, inflammation, organ failure, co-morbidity, co-medication and extracorporeal systems), antibiotic pharmacokinetics is highly variable in pediatric patients and difficult to predict without using population pharmacokinetics models. The intra- and inter-individual variability can result in under- or overexposure in a significant proportion of patients. Therapeutic drug monitoring typically covers assessment of pharmacokinetics and pharmacodynamics, and concurrent dose adaptation after initial standard dosing and drug concentration analysis. Model-informed precision dosing (MIPD) captures drug, disease, and patient characteristics in modeling approaches and can be used to perform Bayesian forecasting and dose optimization. Incorporating MIPD in the electronic patient record system brings pharmacometrics to the bedside of the patient, with the aim of a consisted and optimal drug exposure. In this narrative review, we evaluated studies assessing optimization of antibiotic pharmacotherapy using MIPD in pediatric populations. Four eligible studies involving amikacin and vancomycin were identified from 418 records. Key articles, independent of year of publication, were also selected to highlight important attributes of MIPD. Although very little research has been conducted until this moment, the available data on vancomycin indicate that MIPD is superior compared to conventional dosing strategies with respect to target attainment. The utility of MIPD in pediatrics needs to be further confirmed in frequently used antibiotic classes, particularly aminoglycosides and beta-lactams.
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Affiliation(s)
- Alan Abdulla
- Department of Hospital Pharmacy, Erasmus University Medical Center, Rotterdam, Netherlands
| | - Elma E Edwina
- Department of Hospital Pharmacy, Erasmus University Medical Center, Rotterdam, Netherlands
| | - Robert B Flint
- Department of Hospital Pharmacy, Erasmus University Medical Center, Rotterdam, Netherlands.,Division of Neonatology, Department of Pediatrics, Sophia Children's Hospital, Erasmus University Medical Center, Rotterdam, Netherlands
| | - Karel Allegaert
- Department of Hospital Pharmacy, Erasmus University Medical Center, Rotterdam, Netherlands.,Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, Leuven, Belgium.,Department of Development and Regeneration, KU Leuven, Leuven, Belgium
| | - Enno D Wildschut
- Department of Pediatric Intensive Care, Sophia Children's Hospital, Erasmus University Medical Center, Rotterdam, Netherlands
| | - Birgit C P Koch
- Department of Hospital Pharmacy, Erasmus University Medical Center, Rotterdam, Netherlands
| | - Matthijs de Hoog
- Department of Pediatric Intensive Care, Sophia Children's Hospital, Erasmus University Medical Center, Rotterdam, Netherlands
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3
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Hempel G. Pharmacotherapy in Children and Adolescents: Oncology. Handb Exp Pharmacol 2020; 261:415-440. [PMID: 31792677 DOI: 10.1007/164_2019_306] [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] [Indexed: 06/10/2023]
Abstract
Pharmacotherapy in paediatric oncology is a difficult task. It is challenging to determine the optimal dose in children of different age groups. In addition, anticancer drugs display severe side effects reducing the quality of life. Late effects like secondary tumours and cardiotoxicity can be apparent years after treatment and must be taken into account when planning treatment schedules. Classical cytoreducing agents are still of great importance in treating children with leukaemia and solid tumours. In addition, drugs developed by rational drug design (targeted drugs) are a very important part of many treatment protocols, and newer drugs are emerging in several types of cancer. Unfortunately, there is only limited experience with newer drugs in children, because new drugs are mostly developed for adults. Complicated therapy regimens require a solid knowledge of the pharmacology of the drugs applied. This chapter attempts to introduce some pharmacological knowledge for the most important anticancer drugs in children with a focus on side effects and age-specific considerations.
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Affiliation(s)
- Georg Hempel
- Westfälische Wilhelms-Universität Münster, Institut für Pharmazeutische und Medizinische Chemie, Klinische Pharmazie, Münster, Germany.
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Hong CR, Kang HJ, Moon SJ, Oh J, Hong KT, Choi JY, Yu KS, Shin HY. Pharmacokinetics of high-dose carboplatin in children undergoing high-dose chemotherapy and autologous stem cell transplantation with BSA-based dosing. Bone Marrow Transplant 2019; 55:137-146. [PMID: 31462686 DOI: 10.1038/s41409-019-0655-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2018] [Revised: 05/28/2019] [Accepted: 07/04/2019] [Indexed: 11/09/2022]
Abstract
Body surface area (BSA)-based carboplatin dosing is used in various centers due to practical issues of renal function-based dosing with area under the curve (AUC) measurement. Pharmacokinetic (PK) analysis of high-dose carboplatin was performed in pediatric solid tumor patients undergoing high-dose chemotherapy (HDCT) and autologous stem cell transplantation (ASCT) with BSA-based dosing to calculate the AUCs achieved with this dosing method and to find the correlation between the PK and the renal functions and the adverse events. Carboplatin was administered as once daily intravenous doses at 300, 400, or 500 mg/m2/day over 1 h for 3 or 4 days. On the first and the last day of carboplatin administration, PK samplings were done at 0, 1, 2, and 5 h and only at 0 h on any other days. Mean AUC on the first and the last day were 4.85 ± 0.95 min × mg/mL and 5.27 ± 1.04 min × mg/mL, respectively (n = 23). Overall, negative correlations between the renal functions and the AUCs were mild to moderate, but they were stronger in nephrectomized patients. 51Cr-EDTA clearance decreased with statistical significance with each additional dose of carboplatin (P = 0.020). Optimal high-dose carboplatin dosing method and optimal target AUCs for the different tumors need further analysis.
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Affiliation(s)
- Che Ry Hong
- Department of Pediatrics, Seoul National University College of Medicine, Seoul, Republic of Korea.,Seoul National University Cancer Research Institute, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Hyoung Jin Kang
- Department of Pediatrics, Seoul National University College of Medicine, Seoul, Republic of Korea.,Seoul National University Cancer Research Institute, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Seol Ju Moon
- Department of Clinical Pharmacology and Therapeutics, Seoul National University College of Medicine and Hospital, Seoul, Republic of Korea
| | - Jaeseong Oh
- Department of Clinical Pharmacology and Therapeutics, Seoul National University College of Medicine and Hospital, Seoul, Republic of Korea
| | - Kyung Taek Hong
- Department of Pediatrics, Seoul National University College of Medicine, Seoul, Republic of Korea.,Seoul National University Cancer Research Institute, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Jung Yoon Choi
- Department of Pediatrics, Seoul National University College of Medicine, Seoul, Republic of Korea.,Seoul National University Cancer Research Institute, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Kyung-Sang Yu
- Department of Clinical Pharmacology and Therapeutics, Seoul National University College of Medicine and Hospital, Seoul, Republic of Korea
| | - Hee Young Shin
- Department of Pediatrics, Seoul National University College of Medicine, Seoul, Republic of Korea. .,Seoul National University Cancer Research Institute, Seoul National University College of Medicine, Seoul, Republic of Korea.
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Duong JK, Veal GJ, Nath CE, Shaw PJ, Errington J, Ladenstein R, Boddy AV. Population pharmacokinetics of carboplatin, etoposide and melphalan in children: a re-evaluation of paediatric dosing formulas for carboplatin in patients with normal or mild impairment of renal function. Br J Clin Pharmacol 2018; 85:136-146. [PMID: 30261554 DOI: 10.1111/bcp.13774] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2018] [Revised: 08/01/2018] [Accepted: 09/08/2018] [Indexed: 01/13/2023] Open
Abstract
AIMS Carboplatin dosage is calculated by using the estimated glomerular filtration rate (GFR) to achieve a target plasma area under the plasma concentration-time curve (AUC). The aims of the present study were to investigate factors that influence the pharmacokinetics of carboplatin in children with high-risk neuroblastoma, and whether target exposures for carboplatin were achieved using current treatment protocols. METHODS Data on children receiving high-dose carboplatin, etoposide and melphalan for neuroblastoma were obtained from two study sites [European International Society for Paediatric Oncology (SIOP) Neuroblastoma study, Children's Hospital at Westmead; n = 51]. A population pharmacokinetic model was built for carboplatin to evaluate various dosing formulas. The pharmacokinetics of etoposide and melphalan was also investigated. The final model was used to simulate whether target carboplatin AUC (16.4 mg ml-1 ·min) would be achieved using the paediatric Newell formula, modified Calvert formula and weight-based dosing. RESULTS Allometric weight was the only significant, independent covariate for the pharmacokinetic parameters of carboplatin, etoposide and melphalan. The paediatric Newell formula and modified Calvert formula were suitable for achieving the target AUC of carboplatin for children with a GFR <100 ml min-1 1.73 m-2 but not for those with a GFR ≥100 ml min-1 1.73 m-2 . A weight-based dosing regimen of 50 mg kg-1 achieved the target AUC more consistently than the other formulas, regardless of renal function. CONCLUSIONS GFR did not appear to influence the pharmacokinetics of carboplatin after adjusting pharmacokinetic parameters for weight. This model-based approach validates the use of weight-based dosing as an appropriate alternative for carboplatin in children with either mild renal impairment or normal renal function.
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Affiliation(s)
- J K Duong
- Faculty of Pharmacy, University of Sydney, Sydney, NSW, Australia
| | - G J Veal
- Northern Institute for Cancer Research, Newcastle University, Newcastle upon Tyne, UK
| | - C E Nath
- Faculty of Pharmacy, University of Sydney, Sydney, NSW, Australia.,Departments of Biochemistry and Oncology, The Children's Hospital at Westmead, Westmead, NSW, Australia
| | - P J Shaw
- BMT Services, The Children's Hospital at Westmead, Westmead, NSW, Australia.,Discipline of Child and Adolescent Health, Sydney Medical School, University of Sydney, Sydney, NSW, Australia
| | - J Errington
- Northern Institute for Cancer Research, Newcastle University, Newcastle upon Tyne, UK
| | - R Ladenstein
- Children's Cancer Research Institute, St Anna Children's Hospital, Vienna, Austria
| | - A V Boddy
- Faculty of Pharmacy, University of Sydney, Sydney, NSW, Australia
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van Hasselt JGC, van Eijkelenburg NKA, Beijnen JH, Schellens JHM, Huitema ADR. Optimizing drug development of anti-cancer drugs in children using modelling and simulation. Br J Clin Pharmacol 2014; 76:30-47. [PMID: 23216601 DOI: 10.1111/bcp.12062] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2012] [Accepted: 11/30/2012] [Indexed: 01/04/2023] Open
Abstract
Modelling and simulation (M&S)-based approaches have been proposed to support paediatric drug development in order to design and analyze clinical studies efficiently. Development of anti-cancer drugs in the paediatric population is particularly challenging due to ethical and practical constraints. We aimed to review the application of M&S in the development of anti-cancer drugs in the paediatric population, and to identify where M&S-based approaches could provide additional support in paediatric drug development of anti-cancer drugs. A structured literature search on PubMed was performed. The majority of identified M&S-based studies aimed to use population PK modelling approaches to identify determinants of inter-individual variability, in order to optimize dosing regimens and to develop therapeutic drug monitoring strategies. Prospective applications of M&S approaches for PK-bridging studies have scarcely been reported for paediatric oncology. Based on recent developments of M&S in drug development there are several opportunities where M&S could support more informative bridging between children and adults, and increase efficiency of the design and analysis of paediatric clinical trials, which should ultimately lead to further optimization of drug treatment strategies in this population.
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Affiliation(s)
- Johan G C van Hasselt
- Department of Clinical Pharmacology, Netherlands Cancer Institute; Department of Pharmacy & Pharmacology, Slotervaart Hospital/Netherlands Cancer Institute, Amsterdam, the Netherlands.
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Peters G, Chatelut E, Larsen A, Zaffaroni N. EORTC-related new drug discovery and development activities: role of the Pharmacology and Molecular Mechanisms Group. EJC Suppl 2012. [DOI: 10.1016/s1359-6349(12)70022-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
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8
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Cytostatic drugs in infants: A review on pharmacokinetic data in infants. Cancer Treat Rev 2012; 38:3-26. [DOI: 10.1016/j.ctrv.2011.03.005] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2011] [Revised: 03/21/2011] [Accepted: 03/24/2011] [Indexed: 01/11/2023]
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9
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Abstract
INTRODUCTION Although for conventional dosing of carboplatin, several strategies are available to individualize the dose based on renal function measurements, such approaches are still rare for high-dose regimens with autologous stem cell support. The purpose of this study was to investigate the influence of patient- and regimen-specific factors on the pharmacokinetics of carboplatin and to compare the performance of different dose individualization strategies (Calvert, Newell, Chatelut, flat dosing, dosing according to body surface area). PATIENTS AND METHODS A combined data set with 69 patients from five studies, including 13 pediatric patients, was subject to a population pharmacokinetic analysis using NONMEM. RESULTS The covariate analysis revealed that carboplatin clearance after high-dose chemotherapy was highly related to creatinine clearance, body height, and infusion duration. After inclusion of these covariates, the population parameter variability of clearance decreased from 53% in the base model to 21% in the final model. We also developed an alternative model that related body weight, instead of height, to clearance by means of allometric scaling. An evaluation of the predictive performance of existing a priori dose individualization strategies revealed that flat dosing is appropriate for adult patients with normal renal function receiving a 1-hour infusion. For a long-term infusion schedule, a dose increase may be necessary. The existing dosing strategies performed poorly for the children in our data set. For this subpopulation, our allometric scaling model may be most appropriate. CONCLUSION The two population pharmacokinetic models presented can be applied to estimate individual carboplatin clearance in high-dose chemotherapy based on body weight or height, infusion duration, and creatinine clearance. After prospective evaluation, our models may be suitable for dose adjustments.
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Hulin A, Chatelut E, Royer B, Le Guellec C. Niveau de preuve du suivi thérapeutique pharmacologique du carboplatine. Therapie 2010; 65:157-62. [DOI: 10.2515/therapie/2010021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2010] [Accepted: 03/03/2010] [Indexed: 11/20/2022]
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Hempel G, Müller HJ, Lanvers-Kaminsky C, Würthwein G, Hoppe A, Boos J. A population pharmacokinetic model for pegylated-asparaginase in children. Br J Haematol 2009; 148:119-25. [PMID: 19821822 DOI: 10.1111/j.1365-2141.2009.07923.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We analysed 1221 serum activity measurements in 168 children from the Berlin-Frankfürt-Münster acute lymphoblastic leukaemia studies, ALL-BFM (Berlin-Frankfürt-Münster) 95 and ALL-BFM REZ, in order to develop a pharmacokinetic model describing the activity-time course of pegylated (PEG)-asparaginase for all dose levels. Patients received 500, 750, 1000 or 2500 U/m(2) PEG-asparaginase on up to nine occasions. Serum samples were analysed for asparaginase activity and data analysis was done using nonlinear mixed effects modelling (NONMEM Vers. VI, Globomax, Hanouet, MD, USA). Different linear and nonlinear models were tested. The best model applicable to all dosing groups was a one-compartmental model with clearance (Cl) increasing with time according to the formula: Cl=Cl(i) *e((0.0793 *t)) where Cl(i) = initial clearance and t = time after dose. The parameters found were: volume of distribution (V) 1.02 +/- 26% l/m(2), Cl(i) 59.9 +/- 59% ml/d per m(2) (mean +/- interindividual variability). Interoccasion variability was substantial with 0.183 l/m(2) for V and 44.7 ml/d per m(2) for Cl, respectively. A subgroup of the patients showed a high clearance, probably due to the development of inactivating antibodies. This is the first model able to predict the activity-time course of PEG-asparaginase at different dosing levels and can therefore be used for developing new dosing regimens.
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Affiliation(s)
- Georg Hempel
- Institut für Pharmazeutische und Medizinische Chemie - Klinische Pharmazie-, Westfälische Wilhelms-Universität Münster, Germany.
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Abstract
Population pharmacokinetic (PK) approach is now often used to evaluate PK characteristics of a new compound during its clinical development. Recently, new legislation governing the development and authorization of medicines for use in children aged 0-17 years was introduced in the European Union. Among the strategies proposed in relation to clinical aspects, use of population PKs is stated. In this manuscript, comparison between standard PK and population PK methods will be briefly addressed to understand why the second is particularly adapted to perform PK studies in paediatrics. Then, specific patients' characteristics (covariates) in paediatrics will be presented. Examples of PK and PK-pharmacodynamic (PK-PD) studies will be finally given. The number of population PK studies published still exceeds largely those of PK-PD.
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Affiliation(s)
- Etienne Chatelut
- Institut Claudius-Regaud, EA3035 Université de Toulouse, F-31052 Toulouse cedex, France.
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13
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Royer B, Jullien V, Guardiola E, Heyd B, Chauffert B, Kantelip JP, Pivot X. Population Pharmacokinetics and Dosing Recommendations for Cisplatin during Intraperitoneal Peroperative Administration. Clin Pharmacokinet 2009; 48:169-80. [DOI: 10.2165/00003088-200948030-00003] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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Zandvliet AS, Schellens JHM, Beijnen JH, Huitema ADR. Population Pharmacokinetics and Pharmacodynamics for Treatment Optimization??in Clinical Oncology. Clin Pharmacokinet 2008; 47:487-513. [DOI: 10.2165/00003088-200847080-00001] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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15
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Loh GW, Ting LSL, Ensom MHH. A systematic review of limited sampling strategies for platinum agents used in cancer chemotherapy. Clin Pharmacokinet 2007; 46:471-94. [PMID: 17518507 DOI: 10.2165/00003088-200746060-00002] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Despite evidence in the literature suggesting that a strong correlation exists between the pharmacokinetic parameters and pharmacodynamic effect of anticancer agents, many of these agents are still dosed by body surface area. Therapeutic drug monitoring with the aim of pharmacokinetic-guided dosing would not only maintain target concentrations associated with efficacy but may potentially minimise the likelihood of dose-related systemic toxicities. The pharmacokinetic parameter that displays the best correlation with the pharmacodynamics of anticancer drugs is the area under the plasma concentration-time curve (AUC). However, accurate determination of the AUC requires numerous blood samples over an extended interval, which is not feasible in clinical practice. Therefore, limited sampling strategies (LSSs) have been proposed as a means to accurately and precisely estimate pharmacokinetic parameters with a minimal number of blood samples. LSSs have been developed for many drugs, particularly ciclosporin and other immunosuppressants, as well as for certain anticancer drugs. This systematic review evaluates LSSs developed for the platinum compounds and categorises 18 pertinent citations according to criteria adapted from the US Preventive Services Task Force. Thirteen citations (four level I, six level II-1, three level II-2) pertained to LSSs for carboplatin, four citations (one level II-1, one level II-2, two level III) to cisplatin LSSs, and one citation (level II-2) to nedaplatin. Based on the current evidence, it appears that LSSs may be useful for pharmacokinetic-guided dosage adjustments of carboplatin in both adults and children with cancer. Although some validation studies suggest that LSSs can be extended to different cancer populations or different chemotherapy regimens, other studies dispute this finding. Although the use of LSSs to predict the pharmacokinetic parameters of cisplatin and nedaplatin appear promising, the quality of evidence from published studies does not support routine implementation at this time.LSSs represent one approach in which clinicians can make specific dosage adjustments for individual patients to optimise outcomes. However, the limitations of these strategies must also be taken into consideration. There is also a need for prospective studies to demonstrate that application of LSSs for platinum agents ultimately improves patient response and decreases systemic toxicities.
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Affiliation(s)
- Gabriel W Loh
- Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, British Columbia, Canada
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16
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Hempel G, Boos J. Flat‐Fixed Dosing Versus Body Surface Area–Based Dosing of Anticancer Drugs: There Is a Difference. Oncologist 2007; 12:924-6. [PMID: 17766651 DOI: 10.1634/theoncologist.12-8-924] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Affiliation(s)
- Georg Hempel
- Institut für Pharmazeutische und Medizinische Chemie -Klinische Pharmazie-Hittorfstr. 58-62, 48149 Münster, Germany.
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17
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Ekhart C, de Jonge ME, Huitema ADR, Schellens JHM, Rodenhuis S, Beijnen JH. Flat Dosing of Carboplatin Is Justified in Adult Patients with Normal Renal Function. Clin Cancer Res 2006; 12:6502-8. [PMID: 17085665 DOI: 10.1158/1078-0432.ccr-05-1076] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
PURPOSE The Calvert formula is a widely applied algorithm for the a priori dosing of carboplatin based on patients glomerular filtration rate (GFR) as accurately measured using the 51Cr-EDTA clearance. Substitution of the GFR in this formula by an estimate of creatinine clearance or GFR as calculated by formulae using serum creatinine (SCR; Cockcroft-Gault, Jelliffe, and Wright) is, however, routine clinical practice in many hospitals. The goal of this study was to validate this practice retrospectively in a large heterogeneous adult patient population. EXPERIMENTAL DESIGN Concentration-time data of ultrafilterable platinum of 178 patients (280 courses, 3,119 samples) with different types of cancer receiving carboplatin-based chemotherapy in conventional and high doses were available. Data were described with a linear two-compartment population pharmacokinetic model. Relations between SCR-based formulae for estimating renal function and carboplatin clearance were investigated. RESULTS None of the tested SCR-based estimates of renal function were relevantly related to the pharmacokinetic variables of carboplatin. Neither SCR (median, 51; range, 18-124 micromol/L) nor the estimated GFR using the three different formulae was related to carboplatin clearance. CONCLUSIONS Our data do not support the application of modifications of the Calvert formula by estimating GFR from SCR in the a priori dosing of carboplatin in patients with relatively normal renal function (creatinine clearance, >50 mL/min). For targeted carboplatin exposures, the original Calvert formula, measuring GFR using the 51Cr-EDTA clearance, remains the method of choice. Alternatively, in patients with normal renal function, a flat dose based on the mean population carboplatin clearance should be administered.
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Affiliation(s)
- Corine Ekhart
- Department of Pharmacy and Pharmacology, The Netherlands Cancer Institute/Slotervaart Hospital, Amsterdam, and Faculty of Pharmaceutical Sciences, Utrecht University, the Netherlands.
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Cole M, Boddy AV, Kearns P, Teh KH, Price L, Parry A, Pearson ADJ, Veal GJ. Potential clinical impact of taking multiple blood samples for research studies in paediatric oncology: how much do we really know? Pediatr Blood Cancer 2006; 46:723-7. [PMID: 16007598 DOI: 10.1002/pbc.20463] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Pharmacological studies of anti-cancer agents in children are essential to determine their clinical safety and efficacy, both of which can differ considerably from that observed in adults. However, the potential clinical impact of taking blood samples, in addition to those required for standard clinical practice is commonly a concern for both medical and allied staff and parents. Frequently quoted 'safe limits' of 3%-5% of total blood volume taken on any one study day are not based on published data and may not be acceptable for all patients. This article reviews some of the reasons why clinical pharmacology data for anti-cancer drugs is often lacking in a paediatric patient population, summarises data from a retrospective study investigating the potential impact of repeated blood sampling for research purposes and discusses how this issue may be more systematically addressed in future studies. Research involving children with cancer should be limited to those studies addressing key scientific questions and should be designed to limit both the number and volume of blood samples required.
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Affiliation(s)
- Michael Cole
- Northern Institute for Cancer Research, University of Newcastle upon Tyne, Newcastle upon Tyne, United Kingdom
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Meibohm B, Läer S, Panetta JC, Barrett JS. Population pharmacokinetic studies in pediatrics: issues in design and analysis. AAPS J 2005; 7:E475-87. [PMID: 16353925 PMCID: PMC2750985 DOI: 10.1208/aapsj070248] [Citation(s) in RCA: 144] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2005] [Accepted: 05/04/2005] [Indexed: 12/23/2022] Open
Abstract
The current review addresses the following 3 frequently encountered challenges in the design and analysis of population pharmacokinetic studies in pediatrics: (1) body size adjustments during the development of pharmacostatistical models, (2) design and validation of limited sampling strategies, and (3) the integration of historical priors in data analysis and trial simulation. Size adjustments with empiric approaches based on body weight or body surface area have frequently proven as a pragmatic tool to overcome large size differences in a pediatric study population. Allometric size adjustments, however, provide a more mechanistic, physiologically based approach that, if used a priori, allows delineation of the effect of size from that of other covariates that show a high degree of collinearity. The frequent lack of dense data sets in pediatric clinical pharmacology because of ethical and logistic constraints in study design can be overcome with the application of D-optimality-based limited sampling schemes in combination with Bayesian and nonlinear mixed-effects modeling approaches. Empirically based dose selection and clinical trial designs for pediatric clinical pharmacology studies can be improved by applying clinical trial simulation techniques, especially if they integrate adult and pediatric in vitro and/or in vivo data as historic priors. Although integration of these concepts and techniques in population pharmacokinetic analyses is not only limited to pediatric research, their application allows researchers to overcome some major hurdles frequently encountered in pharmacokinetic studies in pediatrics and, thus, provides the basis for additional clinical pharmacology research in this previously insufficiently studied fraction of the general population.
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Affiliation(s)
- Bernd Meibohm
- Department of Pharmaceutical Sciences, College of Pharmacy, The University of Tennessee Health Science Center, Memphis, TN 38163, USA.
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20
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Groninger E, Proost JH, de Graaf SSN. Pharmacokinetic studies in children with cancer. Crit Rev Oncol Hematol 2005; 52:173-97. [PMID: 15582785 DOI: 10.1016/j.critrevonc.2004.08.007] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/27/2004] [Indexed: 11/23/2022] Open
Abstract
We reviewed the current status of our knowledge of pharmacokinetics and pharmacodynamics of some anti-neoplastic drugs, used in the treatment of childhood cancer. Extrapolation of data from pharmacokinetic studies in adults to the paediatric population is often not feasible. Specific studies in children are needed. Of all reviewed anti-neoplastic drugs methotrexate appears to be most extensively studied. Methotrexate pharmacokinetics is correlated with toxicity and response to therapy, and it has been shown that individualized adaptive dosing of methotrexate is correlated with a better response to therapy without increasing toxicity in children with ALL and osteosarcoma. Of most of the other reviewed anti-neoplastic drugs it is demonstrated that pharmacokinetics is correlated with toxicity, and of some drugs a relationship of pharmacokinetics with response to therapy is demonstrated as well. In case of cytarabine, etoposide, and teniposide, individualized dosing also appears to be feasible. However, there is no evidence that this strategy improves response to therapy. Specifically data on pharmacokinetic and pharmacodynamic correlations and effect of pharmacokinetically guided, individualized dosing are important for the design of optimal cancer chemotherapy for individual patients. Unfortunately for a considerable number of anti-neoplastic drugs these specific data are lacking in children and future research is needed.
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Affiliation(s)
- E Groninger
- Department of Paediatric Oncology Haematology, Beatrix Children's Hospital, Groningen, PO Box 30001, 9700 RB Groningen, The Netherlands.
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Ette EI, Williams PJ. Population Pharmacokinetics I: Background, Concepts, and Models. Ann Pharmacother 2004; 38:1702-6. [PMID: 15328391 DOI: 10.1345/aph.1d374] [Citation(s) in RCA: 131] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
OBJECTIVE To present and emphasize the background, foundations, utility, and conceptual underlying theory of the population pharmacokinetic (PPK) approach with an examination of the advantages when compared with other approaches of pharmacokinetic modeling. DATA SOURCES Information on PPK was retrieved from a MEDLINE search (1979—June 2002) of literature and a bibliographic review of review articles and books. STUDY SELECTION AND DATA EXTRACTION All articles identified from data sources were evaluated and relevant information was included in this review. DATA SYNTHESIS PPK plays a pivotal role in developing dosing strategies for direct patient care and in drug development. PPK is valuable because it targets the patient group that will eventually receive the drug of interest, quantitates pharmacokinetic variability at several levels, and seeks to explain those sources of variability. CONCLUSIONS PPK models have great utility and the applications are many. They are very different from single-subject pharmacokinetic models and therefore require different approaches to model development.
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Affiliation(s)
- Ene I Ette
- Vertex Pharmaceuticals, Inc., Cambridge, MA, USA.
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22
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Tranchand B, Laporte S, Glehen O, Freyer G. Pharmacology of cytotoxic agents: a helpful tool for building dose adjustment guidelines in the elderly. Crit Rev Oncol Hematol 2003; 48:199-214. [PMID: 14607383 DOI: 10.1016/j.critrevonc.2003.05.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Aging is associated with multidimensional changes, including alterations in physiological functions, co-morbidities and poly-medications. These changes may lead to modifications in the absorption, distribution, metabolism and excretion of drugs. The lack of a scientific basis for optimal drug dosing in the elderly is a major problem. The development and validation of guidelines are therefore essential to improve treatment administration and monitoring in elderly patients. Even though it has been widely demonstrated that standard therapies used in adults may be of great benefit in the elderly, there may be a higher incidence of toxicity. This could be avoided by using dosage individualization based on a sound knowledge of the physiological factors implicated in the pharmacokinetic (PK) characteristics of the drugs administered and in their observed pharmacodynamic (PD) effects in each patient. The so-called "population modeling" approach renders such studies feasible by allowing the analysis of PK-PD relationships from sparse observational data.
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23
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Hempel G, Reinhardt D, Creutzig U, Boos J. Population pharmacokinetics of liposomal daunorubicin in children. Br J Clin Pharmacol 2003; 56:370-7. [PMID: 12968981 PMCID: PMC1884379 DOI: 10.1046/j.1365-2125.2003.01886.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
AIMS To investigate the population pharmacokinetics of daunorubicin in children after administration of liposomal daunorubicin (Daunoxome). METHODS Plasma samples from 19 children with relapsed acute myeloic leukaemia and five children with other malignancies were collected. Daunoxome was administered as a 1- to 2.5 h infusion with doses ranging from 30 to 60 mg m(-2). Overall, 214 samples were analysed for daunorubicin using capillary electrophoresis, and population pharmacokinetic modelling was performed using NONMEM. RESULTS The data were best described by a one compartment model. Inclusion of interoccasion variability in the model (16.7% for clearance) improved strongly the precision of the estimates. The inclusion of body surface area or height as a covariate decreased interindividual variability. However, the best fit was obtained using the absolute dose, and when weight was included as a covariate for clearance (CL) and volume of distribution (V ). The final parameter estimates were: CL 6.41 ml h(-1) kg(-1) +/- 0.5 51% and V 65.4 ml kg(-1) +/- 0.5 27% (population mean +/- 0.5 interindividual variability). The area under the curve at a dose of 60 mg m(-2) was 231 mg l (-1)h. CONCLUSIONS In comparison with free daunorubicin, Daunoxome shows a low volume of distribution, a lower clearance and a lower interindividual variability in these parameters. This might be advantageous in reducing the variability in exposure to the drug.
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Affiliation(s)
- Georg Hempel
- Institut für Pharmazeutische und Medizinische Chemie, Westfälische Wilhelms-Universität, Hittorfstrasse 58-62, 48149 Münster, Germany.
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Hempel G, Rübe C, Mosler C, Wienstroer M, Wagner-Bohn A, Schuck A, Willich N, Boos J. Population pharmacokinetics of low-dose paclitaxel in patients with brain tumors. Anticancer Drugs 2003; 14:417-22. [PMID: 12853882 DOI: 10.1097/00001813-200307000-00005] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Our aim was to assess the pharmacokinetics of a low-dose schedule of paclitaxel in combination with radiation therapy in patients with brain tumors. Eighteen patients received 20-50 mg/m2 paclitaxel as a 1-h infusion 18-24 h before radiation with 2 Gy on 5 consecutive days. In total, 156 plasma samples from 13 patients and 38 urine samples from nine patients were collected and analyzed by a validated capillary electrophoresis method. Data analysis was done using NONMEM with a two-compartmental model and proportional error model. No signs of non-linearity in the pharmacokinetic parameters were observed in this dosing range. The median cumulative urinary excretion was 2.4% (range 0.86-7.72%) of the given dose. Plasma clearance was found to be 6.71 l/h+/-70% and central volume of distribution was 3.64 l+/-79% (population mean +/- interindividual variability, respectively). At the time of the radiation, i.e. 24 h after administration with the lowest dose of 20 mg/m2, the mean concentration of paclitaxel was 0.038 mg/l (0.045 microM) in plasma. We conclude that even with the lowest dose of 20 mg/m2 paclitaxel, plasma concentrations at the time of radiation are achieved which are radiosensitizing in vitro.
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Affiliation(s)
- Georg Hempel
- Klinik und Poliklinik für Kinderheilkunde (Pädiatrische Hämatologie/Onkologie), Münster, Germany.
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Rubie H, Doz F, Vassal G, Chastagner P, Gentet JC, Urien S, Bastian G, Drouard-Troalen L, Barberi-Heyob M, Catalin J, Chatelut E. Individual dosing of carboplatin based on drug monitoring in children receiving high-dose chemotherapy. Eur J Cancer 2003; 39:1433-8. [PMID: 12826047 DOI: 10.1016/s0959-8049(03)00314-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Individual dosing of carboplatin based on drug monitoring was performed within a multi-centric phase I study based on high AUC-levels in children. Twelve patients (aged 3-17 years old) have been included: 3, 5, and 4 patients at the overall target ultrafilterable carboplatin AUC of 20, 25, or 30 mg/ml x min, respectively. Carboplatin was administered as a daily 60-min infusion, repeated on five consecutive days. The initial daily dose corresponding to the three first days was calculated according to the carboplatin clearance (CL) predicted from patients' characteristics (body weight, serum creatinine and nephrectomy status). Three blood samples were taken per patient. The individual CL were estimated by MAP (maximum a posteriori approach) Bayesian method implemented in the MP-K program. The doses for day 4 and 5 was adjusted in order to obtain the overall target AUC. Drug monitoring led to a change in the carboplatin dose (overall administered dose versus overall dose planned) ranging from -41% to +45%. Pharmacokinetics were performed at day 5 for 7/12 children: mean relative change between day 1 and day 5 was -11% showing a statistically significant, but limited, decrease of CL from day 1 to day 5. The percentage of difference between the observed and target overall AUC ranged between -7% and +14%. Three patients (one at each AUC level) who were previously treated with cisplatin experienced dose-limiting hearing loss. In conclusion, drug monitoring and dose adjustment is needed for the control of carboplatin plasma exposure when administering high doses of carboplatin in children.
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Affiliation(s)
- H Rubie
- Institut Claudius-Regaud, 20, rue du Pont-Saint-Pierre, F-31052, Toulouse 31052, France
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Urien S, Alexandre J, Raymond E, Brain E, Smith S, Shah A, Cvitkovic E, Lokiec F. Phase I population pharmacokinetics of irofulven. Anticancer Drugs 2003; 14:353-8. [PMID: 12782941 DOI: 10.1097/00001813-200306000-00005] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Our aim was to develop a population pharmacokinetic model for irofulven and to assess covariates that might affect irofulven pharmacokinetics. Irofulven was administered by 5- or 30-min i.v. infusion to cancer patients during a phase I study. Blood samples were collected over 4 h. Plasma samples were analyzed to quantitate irofulven by high-performance liquid chromatography. Population pharmacokinetic analysis was performed using a non-linear mixed effects modeling program, MP2. Fifty-nine patients were available for pharmacokinetic analysis. Irofulven plasma concentration-time profiles were best described by a two-compartment pharmacokinetic model. Clearance and central volume of distribution were not significantly influenced by individual characteristics, i.e. body weight (BW), body surface area (BSA), age and gender. Final parameter estimates of clearance and central volume of distribution were 616 l/h and 37 l, respectively, resulting in a very short terminal half-life of less than 10 min. A relatively high level of variability was observed in irofulven pharmacokinetics, which was mainly due to a significant residual variability, 39%. For a 30-min irofulven infusion, the optimal sampling schedule for clearance estimation using the Bayesian method was the three time points 0.35-0.45, 0.80 and 1-1.2 h from the beginning of a 30-min infusion. We conclude that after i.v. infusion of irofulven, plasma clearance was high and not dependent upon patient age, gender, BSA or BW.
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Affiliation(s)
- S Urien
- Pharmacology Department, Rene Huguenin Cancer Center, Saint-Cloud, France.
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Calvert AH, Egorin MJ. Carboplatin dosing formulae: gender bias and the use of creatinine-based methodologies. Eur J Cancer 2002; 38:11-6. [PMID: 11750834 DOI: 10.1016/s0959-8049(01)00340-9] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Oo C, Barrett J, Hill G, Mann J, Dorr A, Dutkowski R, Ward P. Pharmacokinetics and dosage recommendations for an oseltamivir oral suspension for the treatment of influenza in children. Paediatr Drugs 2001; 3:229-36. [PMID: 11310719 DOI: 10.2165/00128072-200103030-00005] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
OBJECTIVE Oseltamivir (Ro 64-0796) is an ester prodrug of the active metabolite Ro 64-0802 (oseltamivir carboxylate), a potent and selective inhibitor of the neuraminidase enzyme of influenza virus. In this study we report the pharmacokinetics of oseltamivir in healthy children volunteers (study 1) and in children with influenza (study 2). STUDY PARTICIPANTS AND METHODS In study 1, an open-label, single dose study, serial plasma samples were obtained from a total of 18 healthy children (5 to 18 years) who were grouped by age (n = 6 per group) and received single oral doses of oseltamivir 2 mg/kg. In study 2, a randomised, placebo controlled phase III study in paediatric children (1 to 12 years) presenting with influenza symptoms, 199 pharmacokinetic sparse samples were obtained from 87 patients, and serial samples were obtained from 5 patients. Pooled data were compared with those from adult studies. RESULTS Children (1 to 12 years) eliminated the active metabolite faster than both adolescents (13 to 18 years) and adults, resulting in lower exposure to the active drug. In these children, oseltamivir 2 mg/kg twice daily resulted in drug exposures within the range associated with tolerability and efficacy in adults administered approximately 1 mg/kg twice daily. Unit doses of oseltamivir 30, 45 and 60mg oral suspension are recommended twice daily in children weighing < or =15 kg (or < or =33 lb, aged 1 to 3 years), > 15 to 23 kg (or >33 to 51 lb, aged 4 to 7 years) and >23 to 40 kg (or >51 to 88 lb, aged 8 to 12 years), respectively. A 75 mg capsule may be a viable dosage formulation in children (e.g. over 8 years of age) who are able to swallow solid dosage forms. CONCLUSIONS Young children cleared the active metabolite oseltamivir carboxylate at a faster rate than older children and adults. Convenient administration recommendations for the oseltamivir oral suspension in children are possible to maintain drug exposure within the target window.
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Affiliation(s)
- C Oo
- Department of Clinical Pharmacology, Roche Global Development, Nutley, New Jersey 07110, USA.
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Kastrissios H, Ratain MJ. Screening for sources of interindividual pharmacokinetic variability in anticancer drug therapy: utility of population analysis. Cancer Invest 2001; 19:57-64. [PMID: 11291557 DOI: 10.1081/cnv-100000075] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- H Kastrissios
- Department of Pharmaceutics and Pharmacodynamics, College of Pharmacy, University of Illinois at Chicago, 833 South Wood Street (M/C865), Chicago, IL 60612, USA
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Thomas H, Boddy AV, English MW, Hobson R, Imeson J, Lewis I, Morland B, Pearson AD, Pinkerton R, Price L, Stevens M, Newell DR. Prospective validation of renal function-based carboplatin dosing in children with cancer: A United Kingdom Children's Cancer Study Group Trial. J Clin Oncol 2000; 18:3614-21. [PMID: 11054434 DOI: 10.1200/jco.2000.18.21.3614] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
PURPOSE Carboplatin dosing in adults with cancer is based on renal function. The purpose of the current study was to validate a previously developed pediatric carboplatin-dosing formula. PATIENTS AND METHODS Thirty-eight pediatric patients were randomized to receive a carboplatin dose calculated according to surface area or a renal function-based dosing formula. On the next course of therapy, the alternative dosing method was used for each patient. Carboplatin pharmacokinetics (based on free plasma platinum concentrations) were measured after both courses. RESULTS The mean observed areas under the carboplatin concentration-versus-time curve (AUCs) after renal function- and surface area-based dosing were 98% and 95% of the target AUCs, respectively. The variation in the observed AUC was significantly less after renal function-based dosing (F test, P =.02), such that 74% of courses had an observed AUC within +/- 20% of the target value, versus 49% for courses after dosing according to surface area. Only one of 22 courses at the center with the most experience with renal function-based dosing was associated with an AUC outside +/- 20% of the target value, versus nine of 22 courses after surface area-based dosing in the same center. There was a relationship (r(2) =.71) between carboplatin AUC and thrombocytopenia in 10 neuroblastoma patients treated with a combination of carboplatin, vincristine, etoposide, and cyclophosphamide. CONCLUSION Renal function-based carboplatin dosing in children results in more consistent drug exposure than surface area-based drug administration.
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Affiliation(s)
- H Thomas
- Departments of Oncology and Child Health, University of Newcastle, Newcastle, UK
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Gallo JM, Laub PB, Rowinsky EK, Grochow LB, Baker SD. Population pharmacokinetic model for topotecan derived from phase I clinical trials. J Clin Oncol 2000; 18:2459-67. [PMID: 10856106 DOI: 10.1200/jco.2000.18.12.2459] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
PURPOSE To characterize the pharmacokinetics of topotecan in a population model that would identify patient variables or covariates that appreciably impacted on its disposition. PATIENTS AND METHODS All data were collected from 82 patients entered in four different phase I trials that were previously reported as separate studies from 1992 to 1996. All patients received topotecan as a 30-minute constant-rate infusion on a daily-times-five schedule and were selected for this study because their daily dose did not exceed 2.0 mg/m(2). Among the 82 patients were 30 patients classified as having renal insufficiency and 13 patients with hepatic dysfunction. The population pharmacokinetic model was built in sequential manner, starting with a covariate-free model and progressing to a covariate model with the aid of generalized additive modeling. RESULTS A linear two-compartment model characterized total topotecan plasma concentrations (n = 899). Four primary pharmacokinetic parameters (total clearance, volume of the central compartment, distributional clearance, and volume of the peripheral compartment) were related to various combinations of covariates. The relationship for total clearance (TVCL [L/h] = 32.0 + [0.356(WT - 71) + 0.308(HT - 168.5) - 8.42(SCR - 1.1)] x [1 + 0.671 sex]) was dependent on the patients' weight (WT), height (HT), serum creatinine (SCR), and sex and had a moderate ability to predict (r(2) = 0.64) each patient's individual clearance value. The addition of covariates to the population model improved the prediction errors, particularly for clearance. Removal of 10 outlying patients from the analysis improved the ability of the model to predict individual clearance values (r(2) = 0.77). CONCLUSION A population pharmacokinetic model for total topotecan has been developed that incorporates measures of body size and renal function to predict total clearance. The model can be used prospectively to obtain a revised and validated model that can then be used to design individualized dosing regimens.
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Affiliation(s)
- J M Gallo
- Department of Pharmacology, Fox Chase Cancer Center, Philadelphia, PA 19111, USA.
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Abstract
Therapeutic drug monitoring is not routinely used for cytotoxic agents. There are several reasons, but one major drawback is the lack of established therapeutic concentration ranges. Combination chemotherapy makes the establishment of therapeutic ranges for individual drugs difficult, the concentration-effect relationship for a single drug may not be the same as that when the drug is used in a drug combination. Pharmacokinetic optimization protocols for many classes of cytotoxic compounds exist in specialized centres, and some of these protocols are now part of large multicentre trials. Nonetheless, methotrexate is the only agent which is routinely monitored in most treatment centres. An additional factor, especially in antimetabolite therapy, is the existence of pharmacogenetic enzymes which play a major role in drug metabolism. Monitoring of therapy could include assay of phenotypic enzyme activities or genotype in addition to, or instead of, the more traditional measurement of parent drug or drug metabolites. The cytotoxic activities of mercaptopurine and fluorouracil are regulated by thiopurine methyltransferase (TPMT) and dihydropyrimidine dehydrogenase (DPD), respectively. Lack of TPMT functional activity produces life-threatening mercaptopurine myelotoxicity. Very low DPD activity reduces fluorouracil breakdown producing severe cytotoxicity. These pharmacogenetic enzymes can influence the bioavailability, pharmacokinetics, toxicity and efficacy of their substrate drugs.
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Affiliation(s)
- L Lennard
- University of Sheffield, Clinical Sciences Division (CSUH), Royal Hallamshire Hospital, UK
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Abstract
Cancer is a common cause of death, and improvements in treatment are desperately needed. The high degree of variation in systemic exposure for a given dose and the relationships between blood concentrations and either toxic or antitumor effects would suggest that therapeutic drug monitoring is a potential mechanism for improving the treatment of individual patients. In this review, the case for therapeutic drug monitoring is made in a select number of commonly used cancer drugs and areas that require more concerted effort are highlighted.
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Affiliation(s)
- H L McLeod
- Department of Medicine and Therapeutics, University of Aberdeen, UK
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Fujiwara Y, Takahashi T, Yamakido M, Ohune T, Tsuya T, Egorin MJ. Re: prediction of carboplatin clearance from standard morphological and biological patient characteristics. J Natl Cancer Inst 1997; 89:260-2. [PMID: 9017009 DOI: 10.1093/jnci/89.3.260-a] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
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Peng B, Tilby MJ, English MW, Price L, Pearson AD, Boddy AV, Newell DR. Platinum-DNA adduct formation in leucocytes of children in relation to pharmacokinetics after cisplatin and carboplatin therapy. Br J Cancer 1997; 76:1466-73. [PMID: 9400943 PMCID: PMC2228168 DOI: 10.1038/bjc.1997.579] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Platinum (Pt)-DNA adducts were measured in peripheral blood leucocytes (PBLs) from 24 children with solid tumours after standard cisplatin and/or carboplatin treatment. The relationship between Pt-DNA adduct levels and pharmacokinetics of cisplatin and carboplatin was investigated. Adduct measurements were performed by competitive enzyme-linked immunosorbent assay (ELISA) and plasma unbound Pt concentrations were measured by atomic absorption spectrophotometry (AAS). There was considerable interindividual variation in Pt-DNA adduct level that was weakly correlated (r2 = 0.32) with the area under the unbound drug concentration vs time curve (AUC) at 6 h after the start of cisplatin infusion, indicating that the variation in Pt-DNA adduct levels was primarily determined by factors other than AUC. No clear relationship between AUC and adduct levels was seen at 24 and 48 h after cisplatin or at 6, 24 or 48 h after carboplatin. Carboplatin produced lower levels of immunoreactive adducts than did cisplatin (1.3 +/- 0.6 nmol Pt g-1 DNA vs 3.2 +/- 1.7 nmol Pt g-1 DNA), despite a 20-fold higher unbound drug AUC for carboplatin (8.0 +/- 3.5 mg ml-1 min vs 0.4 +/- 0.2 mg ml-1 min). This study demonstrates that, after cisplatin and carboplatin treatment the drug-target interaction is determined by both pharmacokinetic and, predominantly, cellular factors. Intrinsic differences between the two complexes, primarily reactivity, probably explain the lower adduct levels observed after carboplatin treatment.
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Affiliation(s)
- B Peng
- Department of Oncology, Medical School, The University of Newcastle upon Tyne, UK
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