A Physiologically Based Pharmacokinetic Model of Ertapenem in Pediatric Patients With Renal Impairment

Chronic kidney disease and physiologically based pharmacokinetic modeling: a critical review of existing models

INTRODUCTION

Physiologically based pharmacokinetic (PBPK) modeling is a paradigm shift in this era for determining the exposure of drugs in pediatrics, geriatrics, and patients with chronic diseases where clinical trials are difficult to conduct.

AREAS COVERED

This review has collated data regarding published PBPK models on chronic kidney disease (CKD), including the drug and system-specific input model parameters and model evaluation criteria. Four databases were used from 13th June 2023 to 10th July 2023 for identifying the relevant studies that met the inclusion/exclusion criteria. Alterations in plasma protein (albumin/alpha-1 acid glycoprotein), gastric emptying time, hematocrit, small intestinal transit time, the abundance of cytochrome (CYP) 450 enzymes, glomerular filtration rate, and physicochemical parameters for different drugs were explicitly elaborated from earlier reported studies. Moreover, model evaluation depicted that models in CKD for most of the included drugs were within the allowed two-fold error range.

EXPERT OPINION

This review will provide insights for researchers on applying PBPK models in managing patients with different levels of CKD to prevent undesirable side effects and increase the effectiveness of drug therapy.

Pharmacokinetics, Pharmacodynamics and Safety of Janagliflozin in Chinese Type 2 Diabetes Mellitus Patients with Renal Impairment

BACKGROUND

Janagliflozin is a novel sodium-glucose cotransport-2 inhibitor. Despite its remarkable effect in glycemic control, no systematic research has evaluated the effect of renal impairment (RI) on its pharmacokinetics and pharmacodynamics.

METHODS

Here, patients with T2DM (n = 30) were divided into normal renal function (eGFR ≥ 90 mL/min/1.73 m2), mild RI (eGFR between 60 and 89 mL/min/1.73 m2), moderate RI-I (eGFR between 45 and 59 mL/min/1.73 m2), and moderate RI-II (eGFR between 30 and 44 mL/min/1.73 m2) groups. They were administered 50 mg janagliflozin orally, and plasma and urine samples were collected for the determination of janagliflozin concentration.

RESULTS

Following oral administration, janagliflozin was rapidly absorbed, with the time to Cmax of 2-6 h for janagliflozin and 3-6 h for its metabolite XZP-5185. Plasma exposure levels were similar for janagliflozin in T2DM patients with or without RI but decreased for the metabolite XZP-5185 in T2DM patients with eGFR between 45 and 89 mL/min/1.73 m2. Janagliflozin significantly promoted the excretion of urinary glucose, even in patients with reduced eGFR. Janagliflozin was well tolerated in patients with T2DM with or without RI, and no serious adverse events (SAEs) occurred during this trial.

CONCLUSIONS

The exposure levels of janagliflozin in T2DM patients were slightly increased with worsening of RI (i.e., 11% increase in the AUC in patients with moderate RI compared with the normal renal function group). Despite worsening of renal function, janagliflozin exerted a significant pharmacologic effect and was well tolerated, even in patients with moderate RI, implying a promising role in the treatment of patients with in T2DM.

REGISTRATION

China Drug Trial register ( http://www.chinadrugtrials.org.cn/I ) identifier no.: CTR20192721.

Lamivudine and Emtricitabine Dosing Proposal for Children with HIV and Chronic Kidney Disease, Supported by Physiologically Based Pharmacokinetic Modelling

Dose recommendations for lamivudine or emtricitabine in children with HIV and chronic kidney disease (CKD) are absent or not supported by clinical data. Physiologically based pharmacokinetic (PBPK) models have the potential to facilitate dose selection for these drugs in this population. Existing lamivudine and emtricitabine compound models in Simcyp^® (v21) were verified in adult populations with and without CKD and in non-CKD paediatric populations. We developed paediatric CKD population models reflecting subjects with a reduced glomerular filtration and tubular secretion, based on extrapolation from adult CKD population models. These models were verified using ganciclovir as a surrogate compound. Then, lamivudine and emtricitabine dosing strategies were simulated in virtual paediatric CKD populations. The compound and paediatric CKD population models were verified successfully (prediction error within 0.5- to 2-fold). The mean AUC ratios in children (GFR-adjusted dose in CKD population/standard dose in population with normal kidney function) were 1.15 and 1.23 for lamivudine, and 1.20 and 1.30 for emtricitabine, with grade-3- and -4-stage CKD, respectively. With the developed paediatric CKD population PBPK models, GFR-adjusted lamivudine and emtricitabine dosages in children with CKD resulted in adequate drug exposure, supporting paediatric GFR-adjusted dosing. Clinical studies are needed to confirm these findings.

Pan-Genomics of Escherichia albertii for Antibiotic Resistance Profiling in Different Genome Fractions and Natural Product Mediated Intervention: In Silico Approach

Escherichia albertii is an emerging, enteric pathogen of significance. It was first isolated in 2003 from a pediatric diarrheal sample from Bangladesh. In this study, a comprehensive in silico strategy was followed to first list out antibiotic-resistant genes from core, accessory and unique genome fractions of 95 available genomes of E. albertii. Then, 56 drug targets were identified from the core essential genome. Finally, ZipA, an essential cell division protein that stabilizes the FtsZ protofilaments by cross-linking them and serves as a cytoplasmic membrane anchor for the Z ring, was selected for further downstream processing. It was computationally modeled using a threading approach, followed by virtual screening of two phytochemical libraries, Ayurvedic (n = 2103 compounds) and Traditional Chinese Medicine (n = 36,043 compounds). ADMET profiling, followed by PBPK modeling in the central body compartment, in a population of 250 non-diseased, 250 cirrhotic and 250 renally impaired people was attempted. ZINC85624912 from Chinese medicinal library showed the highest bioavailability and plasma retention. This is the first attempt to simulate the fate of natural products in the body through PBPK. Dynamics simulation of 20 ns for the top three compounds from both libraries was also performed to validate the stability of the compounds. The obtained information from the current study could aid wet-lab scientists to work on the scaffold of screened drug-like compounds from natural resources and could be useful in our quest for therapy against antibiotic-resistant E. albertii.

Prediction of Janagliflozin Pharmacokinetics in Type 2 Diabetes Mellitus Patients with Liver Cirrhosis or Renal Impairment Using a Physiologically Based Pharmacokinetic Model

Janagliflozin is a sodium-glucose cotransporter 2 (SGLT2) inhibitor for type 2 diabetes mellitus (T2DM). The janagliflozin pharmacokinetics (PK) in T2DM patients with cirrhosis or renal impairment (RI) are unknown. To predict the janagliflozin PK in these patients, we constructed a physiologically based PK (PBPK) model that predicted the janagliflozin PK in normal animals. The model was extrapolated to healthy humans and optimized with the measured data. A PBPK model for T2DM patients was developed and optimized with the measured data. Based on the physiological alterations in cirrhosis or RI patients, the T2DM model was applied to predict the janagliflozin PK in these patients. Results were validated using fold error values. The predicted AUC values were 21880, 24881, 26996, and 28419 ng/ml·h in T2DM patients with no cirrhosis, Child-Pugh-A, B, and C, respectively, and those in T2DM patients with RI-mild, RI-moderate, and RI-severe were 21810, 21840, and 22845 ng/ml·h, respectively. Janagliflozin exposure increased with increasing cirrhosis severity, whereas it remained stable regardless of the RI severity. The PBPK model predicted the janagliflozin PK in patients with T2DM and liver cirrhosis or RI. Dose adjustment is less critical for these patients. Risk benefit assessment in janagliflozin dosing for T2DM patients with liver disease is recommended.

Physiologically based pharmacokinetic modeling of daptomycin dose optimization in pediatric patients with renal impairment

Background and Objective: Daptomycin is used to treat Gram-positive infections in adults and children and its dosing varies among different age groups. We focused on the pharmacokinetics of daptomycin in children with renal impairment, which has not been evaluated.

Methods: A physiologically based pharmacokinetic (PBPK) model of daptomycin was established and validated to simulate its disposition in healthy populations and adults with renal impairment, along with a daptomycin exposure simulated in pediatric patients with renal impairment.

Results: The simulated PBPK modeling results for various regimens of intravenously administered daptomycin were consistent with observed data according to the fold error below the threshold of 2. The Cmax and AUC of daptomycin did not differ significantly between children with mild-to-moderate renal impairment and healthy children. The AUC increased by an average of 1.55-fold and 1.85-fold in severe renal impairment and end-stage renal disease, respectively. The changes were more significant in younger children and could reach a more than 2-fold change. This scenario necessitates further daptomycin dose adjustments.

Conclusion: Dose adjustments take into account the efficacy and safety of the drug; however, the steady-state Cmin of daptomycin may be above 24.3 mg/L in a few instances. We recommend monitoring creatine phosphokinase more than once a week when using daptomycin in children with renal impairment.

Anti-infective Medicines Use in Children and Neonates With Pre-existing Kidney Dysfunction: A Systematic Review

Background

Dosing recommendations for anti-infective medicines in children with pre-existing kidney dysfunction are derived from adult pharmacokinetics studies and adjusted to kidney function. Due to neonatal/pediatric age and kidney impairment, modifications in renal clearance and drug metabolism make standard anti-infective dosing for children and neonates inappropriate, with a risk of drug toxicity or significant underdosing. The aim of this study was the systematic description of the use of anti-infective medicines in pediatric patients with pre-existing kidney impairment.

Methods

A systematic review of the literature was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The EMBASE, Medline and Cochrane databases were searched on September 21st, 2021. Studies in all languages reporting data on pre-defined outcomes (pharmacokinetics-PK, kidney function, safety and efficacy) regarding the administration of anti-infective drugs in children up to 18 years with pre-existing kidney dysfunction were included.

Results

29 of 1,792 articles were eligible for inclusion. There were 13 case reports, six retrospective studies, nine prospective studies and one randomized controlled trial (RCT), reporting data on 2,168 pediatric patients. The most represented anti-infective class was glycopeptides, with seven studies on vancomycin, followed by carbapenems, with five studies, mostly on meropenem. Antivirals, aminoglycosides and antifungals counted three articles, followed by combined antibiotic therapy, cephalosporins, lipopeptides with two studies, respectively. Penicillins and polymixins counted one study each. Nine studies reported data on patients with a decreased kidney function, while 20 studies included data on kidney replacement therapy (KRT). Twenty-one studies reported data on PK. In 23 studies, clinical outcomes were reported. Clinical cure was achieved in 229/242 patients. There were four cases of underdosing, one case of overdosing and 13 reported deaths.

Conclusion

This is the first systematic review providing evidence of the use of anti-infective medicines in pediatric patients with impaired kidney function or requiring KRT. Dosing size or interval adjustments in pediatric patients with kidney impairment vary according to age, critical illness status, decreased kidney function and dialysis type. Our findings underline the relevance of population PK in clinical practice and the need of developing predictive specific models for critical pediatric patients.

Ceftaroline Dosage Optimized for Pediatric Patients With Renal Impairment Using Physiologically Based Pharmacokinetic Modeling

Ceftaroline fosamil is a fifth-generation cephalosporin approved as a treatment for adults and children with community-acquired bacterial pneumonia and acute bacterial skin and skin structure infections. However, its pharmacokinetics have not been fully evaluated in children with renal impairment. This study aimed to propose proper ceftaroline dosages optimized for the renally impaired pediatric population using physiologically based pharmacokinetic (PBPK) modeling. A PBPK model of ceftaroline was established and verified to simulate its disposition in the healthy population and renally impaired adults and to predict the exposure in renally impaired pediatric patients. Consistency was confirmed between simulated and observed data after intravenous administration of various ceftaroline regimens; fold errors were within the 2-fold error range. Among 6-year-old children, healthy subjects had 1.5-fold, 2-fold, and 2.6-fold lower areas under the plasma concentration-time curve (AUCs) than the moderate, severe, and end-stage renally impaired patient groups, respectively; among 1-year-old children, healthy subjects had 1.5-fold, 2.1-fold, and 2.5-fold lower AUCs than the respective renally impaired patient groups; among 1-month-old children, healthy subjects had 1.5-fold, 1.8-fold, and 2.2-fold lower AUCs than the respective renally impaired patient groups. The proposed dosage should be adjusted to 8, 6, and 5 mg/kg every 8 hours for patients aged ≥2 years to <18 years (≤33 kg) with moderate, severe, and end-stage renal impairment, respectively; 5, 4, and 3 mg/kg every 8 hours for patients aged 2 months to <2 years with moderate, severe, and end-stage renal impairment, respectively; 4, 3.5, and 2.5 mg/kg every 8 hours for patients 0 to <2 months of age with moderate, severe, and end-stage renal impairment, respectively. Furthermore, pharmacodynamic investigations demonstrated that adequate antimicrobial effects were attained at the proposed doses in 3 age groups. Hence, our PBPK model can be an effective tool to support ceftaroline dosage proposals for renally impaired pediatric patients.

Physiologically Based Pharmacokinetic Modeling and Dose Adjustment of Teicoplanin in Pediatric Patients With Renal Impairment

The pharmacokinetics of teicoplanin differs in children as compared with adults, and especially in renally impaired pediatric patients. Inappropriate empirical antibacterial therapy may lead to treatment-related antibacterial resistance and increased toxicity, making adjustment of the dosage regimen essential. In the present study, physiologically based pharmacokinetic (PBPK) models were developed to define the appropriate dosage regimen for pediatric patients with differing renal function. Our PBPK models accurately predicted teicoplanin exposures in both adult and pediatric subjects after single and multiple intravenous infusions, with a <1.36-fold error between predicted and observed data, and all observed data were within minimal and maximal data of the corresponding population simulation. The area under the plasma concentration-time curve was predicted to increase 1.25-fold, 1.95-fold, and 2.82-fold in pediatric patients with mild, moderate, and severe renal impairment, respectively, relative to that of healthy children. Subsequently, the results of Monte Carlo simulations indicated that the recommended dosing of 12, 9.5, 6, and 4 mg/kg at 12-hour intervals would be appropriate in pediatric patients with normal renal function and in those with mild, moderate, and severe renal impairment, respectively, at a susceptible minimum inhibitory concentration <2 mg/L. In conclusion, our PBPK model with an incorporated Monte Carlo simulation can provide improved guidance on dosing in pediatric patients with differing renal function and provide a basis for precision therapy with teicoplanin.

Physiologically Based Pharmacokinetic Models Are Effective Support for Pediatric Drug Development

Pediatric drug development faces many difficulties. Traditionally, pediatric drug doses are simply calculated linearly based on the body weight, age, and body surface area of adults. Due to the ontogeny of children, this simple linear scaling may lead to drug overdose in pediatric patients. The physiologically based pharmacokinetic (PBPK) model, as a mathematical model, contributes to the research and development of pediatric drugs. An example of a PBPK model guiding drug dose selection in pediatrics has emerged and has been approved by the relevant regulatory agencies. In this review, we discuss the principle of the PBPK model, emphasize the necessity of establishing a pediatric PBPK model, introduce the absorption, distribution, metabolism, and excretion of the pediatric PBPK model, and understand the various applications and related prospects of the pediatric PBPK model.

Physiologically based pharmacokinetic (PBPK) modeling of RNAi therapeutics: Opportunities and challenges

Physiologically based pharmacokinetic (PBPK) modeling is a powerful tool with many demonstrated applications in various phases of drug development and regulatory review. RNA interference (RNAi)-based therapeutics are a class of drugs that have unique pharmacokinetic properties and mechanisms of action. With an increasing number of RNAi therapeutics in the pipeline and reaching the market, there is a considerable amount of active research in this area requiring a multidisciplinary approach. The application of PBPK models for RNAi therapeutics is in its infancy and its utility to facilitate the development of this new class of drugs is yet to be fully evaluated. From this perspective, we briefly discuss some of the current computational modeling approaches used in support of efficient development and approval of RNAi therapeutics. Considerations for PBPK model development are highlighted both in a relative context between small molecules and large molecules such as monoclonal antibodies and as it applies to RNAi therapeutics. In addition, the prospects for drawing upon other recognized avenues of PBPK modeling and some of the foreseeable challenges in PBPK model development for these chemical modalities are briefly discussed. Finally, an exploration of the potential application of PBPK model development for RNAi therapeutics is provided. We hope these preliminary thoughts will help initiate a dialogue between scientists in the relevant sectors to examine the value of PBPK modeling for RNAi therapeutics. Such evaluations could help standardize the practice in the future and support appropriate guidance development for strengthening the RNAi therapeutics development program.

Dosage Adjustment for Ceftazidime in Pediatric Patients With Renal Impairment Using Physiologically Based Pharmacokinetic Modeling

Physiologically based pharmacokinetic (PBPK) modeling has unique advantages in investigating the pharmacokinetics of drugs in special populations. Our aim is to design optimized dosing regimens for ceftazidime in renally-impaired pediatric patients using PBPK modeling. Models for healthy and renally-impaired adults were developed, verified, and adapted for children to predict ceftazidime exposure in pediatric patients with varying degrees of renal impairment, capturing age- and weight-related pharmacokinetic changes. We derived a dosage-adjusted regimen for renally-impaired children based on pharmacokinetic data and evaluated the pharmacodynamics of ceftazidime. The PBPK models adequately predicted ceftazidime exposures in populations after single- and multi-dose administrations, with fold error values within 1.1 between simulated and observed data. In moderate, severe, and end-stage renally-impaired pediatric patients, the areas under the plasma concentration-time curves (AUCs) were 1.87-fold, 3.56-fold, and 6.19-fold higher, respectively, than in healthy children when treated with the same dose of 50 mg/kg. Pharmacodynamic verification indicated that the recommended doses of 28, 15, and 8 mg/kg administered three times daily (every 8 h) to pediatric patients with moderate, severe, and end-stage renal disease, respectively, were sufficient to attain the target of maintaining the free plasma concentration at or above minimum inhibitory concentration (MIC) during 70% of the dosing interval (70% fT > MIC: nearly 100% target attainment for susceptible MIC of 4 mg/L and >70% for intermediate MIC of 8 mg/L). Our PBPK model can be an effective tool to support dosing recommendations in pediatric patients with different degrees of renal impairment.