Abstract:Physiologically based pharmacokinetic (PBPK) modeling and classical population pharmacokinetic (PK) model‐based simulations are increasingly used to answer various drug development questions. In this study, we propose a methodology to optimize the development of drugs, primarily cleared by the kidney, using model‐based approaches to determine the need for a dedicated renal impairment (RI) study. First, the impact of RI on drug exposure is simulated via PBPK modeling and then confirmed using classical populatio… Show more
“…Generally, PK profiles of drugs are expected to differ in cancer populations compared with profiles in healthy subjects. In many cases, clearance of anti-cancer drugs decreases in cancer patients compared with healthy individuals (Piotrovsky et al, 1998;Houk et al, 2009;Hudachek et al, 2010) for various reasons, including co-morbidities, such as hepatic and renal impairment in cancer patients (Suri et al, 2015). Another possible reason may be changes in MPPGL or CPPGL and differences in the expression of enzymes and transporters (Gao et al, 2016;Billington et al, 2018).…”
In vitro-in vivo extrapolation (IVIVE) linked with physiologically based pharmacokinetic (PBPK) modelling is used to predict the fates of drugs in patients. Ideally, the IVIVE-PBPK models should incorporate "systems" information accounting for characteristics of the specific target population. There is a paucity of such scaling factors in cancer, particularly microsomal protein per gram of liver (MPPGL) and cytosolic protein per gram of liver (CPPGL). In this study, cancerous and histologically normal liver tissue from 16 patients with colorectal liver metastasis (CRLM) were fractionated to microsomes and cytosol.Protein content was measured in homogenates, microsomes and cytosol. The loss of microsomal protein during fractionation was accounted for using corrections based on NADPH cytochrome P450 reductase activity in different matrices. MPPGL was significantly lower in cancerous tissue (24.8 ± 9.8 mg/g) than histologically normal tissue (39.0 ± 13.8 mg/g). CPPGL in cancerous tissue was 42.1 ± 12.9 mg/g compared with 56.2 ± 16.9 mg/g in normal tissue. No correlations between demographics (sex, age and BMI) and MPPGL or CPPGL were apparent in the data. The generated scaling factors together with assumptions regarding the relative volumes of cancerous versus non-cancerous tissue were used to simulate plasma exposure of drugs with different extraction ratios. The PBPK simulations revealed a substantial difference in drug exposure (AUC), up to 3.3-fold, when using typical scaling factors (healthy population) instead of disease-related parameters in cancer population. These indicate the importance of using population-specific scalars in IVIVE-PBPK for different disease states.
“…Generally, PK profiles of drugs are expected to differ in cancer populations compared with profiles in healthy subjects. In many cases, clearance of anti-cancer drugs decreases in cancer patients compared with healthy individuals (Piotrovsky et al, 1998;Houk et al, 2009;Hudachek et al, 2010) for various reasons, including co-morbidities, such as hepatic and renal impairment in cancer patients (Suri et al, 2015). Another possible reason may be changes in MPPGL or CPPGL and differences in the expression of enzymes and transporters (Gao et al, 2016;Billington et al, 2018).…”
In vitro-in vivo extrapolation (IVIVE) linked with physiologically based pharmacokinetic (PBPK) modelling is used to predict the fates of drugs in patients. Ideally, the IVIVE-PBPK models should incorporate "systems" information accounting for characteristics of the specific target population. There is a paucity of such scaling factors in cancer, particularly microsomal protein per gram of liver (MPPGL) and cytosolic protein per gram of liver (CPPGL). In this study, cancerous and histologically normal liver tissue from 16 patients with colorectal liver metastasis (CRLM) were fractionated to microsomes and cytosol.Protein content was measured in homogenates, microsomes and cytosol. The loss of microsomal protein during fractionation was accounted for using corrections based on NADPH cytochrome P450 reductase activity in different matrices. MPPGL was significantly lower in cancerous tissue (24.8 ± 9.8 mg/g) than histologically normal tissue (39.0 ± 13.8 mg/g). CPPGL in cancerous tissue was 42.1 ± 12.9 mg/g compared with 56.2 ± 16.9 mg/g in normal tissue. No correlations between demographics (sex, age and BMI) and MPPGL or CPPGL were apparent in the data. The generated scaling factors together with assumptions regarding the relative volumes of cancerous versus non-cancerous tissue were used to simulate plasma exposure of drugs with different extraction ratios. The PBPK simulations revealed a substantial difference in drug exposure (AUC), up to 3.3-fold, when using typical scaling factors (healthy population) instead of disease-related parameters in cancer population. These indicate the importance of using population-specific scalars in IVIVE-PBPK for different disease states.
“…The mechanistic nature of PBPK models permits integration of data from in vitro and in vivo studies and can interpolate between organisms (eg, animals to humans) as well as developmental stages (eg, adults to pediatrics). Such PBPK models can complement population PK modeling and simulation and facilitate implementation of a predict‐learn‐confirm approach in drug development . Johnson et al evaluated prediction of CL for 11 drugs, including gentamicin and vancomycin, in neonates, infants, and children with normal kidney and hepatic function and concluded that renal CL of gentamicin was underpredicted in children <5 years of age, whereas the prediction for vancomycin was reasonable .…”
Sepsis remains a major cause of mortality and morbidity in neonates, and, as a consequence, antibiotics are the most frequently prescribed drugs in this vulnerable patient population. Growth and dynamic maturation processes during the first weeks of life result in large inter- and intrasubject variability in the pharmacokinetics (PK) and pharmacodynamics (PD) of antibiotics. In this review we (1) summarize the available population PK data and models for primarily renally eliminated antibiotics, (2) discuss quantitative approaches to account for effects of growth and maturation processes on drug exposure and response, (3) evaluate current dose recommendations, and (4) identify opportunities to further optimize and personalize dosing strategies of these antibiotics in preterm and term neonates. Although population PK models have been developed for several of these drugs, exposure-response relationships of primarily renally eliminated antibiotics in these fragile infants are not well understood, monitoring strategies remain inconsistent, and consensus on optimal, personalized dosing of these drugs in these patients is absent. Tailored PK/PD studies and models are useful to better understand relationships between drug exposures and microbiological or clinical outcomes. Pharmacometric modeling and simulation approaches facilitate quantitative evaluation and optimization of treatment strategies. National and international collaborations and platforms are essential to standardize and harmonize not only studies and models but also monitoring and dosing strategies. Simple bedside decision tools assist clinical pharmacologists and neonatologists in their efforts to fine-tune and personalize the use of primarily renally eliminated antibiotics in term and preterm neonates.
“…This case illustrates how PBPK modeling can inform appropriate
dosing of renal impairment (RI) patients in phase I/III studies and thereby enable
characterization of safety and efficacy in the RI patients during the late stage of
drug development 17 . Data from human ADME study revealed that
orteronel (see last example) is a drug that is primarily cleared by kidney excretion.…”
Section: Dose Guidance For Renal Impairment Patients a Case
Studymentioning
Physiologically based pharmacokinetic (PBPK) modeling and
simulation can be used to predict the pharmacokinetic behavior of drugs in humans
using preclinical data. It can also explore the effects of various physiologic
parameters such as age, ethnicity, or disease status on human pharmacokinetics, as
well as guide dose and dose regiment selection and aid drug–drug interaction risk
assessment. PBPK modeling has developed rapidly in the last decade within both the
field of academia and the pharmaceutical industry, and has become an integral tool in
drug discovery and development. In this mini-review, the concept and methodology of
PBPK modeling are briefly introduced. Several case studies were discussed on how PBPK
modeling and simulation can be utilized through various stages of drug discovery and
development. These case studies are from our own work and the literature for better
understanding of the absorption, distribution, metabolism and excretion (ADME) of a
drug candidate, and the applications to increase efficiency, reduce the need for
animal studies, and perhaps to replace clinical trials. The regulatory acceptance and
industrial practices around PBPK modeling and simulation is also
discussed.
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