Pharmacokinetics of darbepoetin alfa after single, intravenous or subcutaneous administration in Japanese pediatric patients with chronic kidney disease

A Simple Method for the Prediction of Therapeutic Proteins (Monoclonal and Polyclonal Antibodies and Non-Antibody Proteins) for First-in-Pediatric Dose Selection: Application of Salisbury Rule

In order to conduct a pediatric clinical trial, it is important to optimize pediatric dose as accurately as possible. In this study, a simple weight-based method known as ‘Salisbury Rule’ was used to predict pediatric dose for therapeutic proteins and was then compared with the observed pediatric dose. The observed dose was obtained mainly from the FDA package insert and if dosing information was not available from the FDA package insert then the observed dose was based on the dose given to an age group in a particular study. It was noted that the recommended doses of most of the therapeutic proteins were extrapolated to pediatrics from adult dose based on per kilogram (kg) body weight basis. Since it is widely believed that pediatric dose should be selected based on the pediatric clearance (CL), a CL based pediatric dose was projected from the following equation: Dose in children = Adult dose × (Observed CL in children/Observed adult CL). In this study, this dose was also considered observed pediatric dose for comparison. A ±30% prediction error (predicted vs. observed) was considered acceptable. There were 21 monoclonal antibodies, 5 polyclonal antibodies in children ≥ 2 years of age, 4 polyclonal antibodies in preterm and term neonates, and 11 therapeutic proteins (non-antibodies) in the study. In children < 30 kg body weight, the predicted doses were within 0.5−1.5-fold prediction error for 87% (monoclonal antibody), 100% (polyclonal antibody), and 92% (non-antibodies) observations. In children > 30 kg body weight, the predicted doses were within 0.5−1.5-fold prediction error for 96% (monoclonal antibody), 100% (polyclonal antibody), and 100% (non-antibodies) observations. The Salisbury Rule mimics more to CL-based dose rather than per kg body weight-based extrapolated dose from adults. The Salisbury Rule for the pediatric dose prediction can be used to select first-in-children dose in pediatric clinical trials and may be in clinical settings.

Prediction of Clearance of Monoclonal and Polyclonal Antibodies and Non-Antibody Proteins in Children: Application of Allometric Scaling

Allometric scaling can be used for the extrapolation of pharmacokinetic parameters from adults to children. The objective of this study was to predict clearance of therapeutic proteins (monoclonal and polyclonal antibodies and non-antibody proteins) allometrically in preterm neonates to adolescents. There were 13 monoclonal antibodies, seven polyclonal antibodies, and nine therapeutic proteins (non-antibodies) in the study. The clearance of therapeutic proteins was predicted using the age dependent exponents (ADE) model and then compared with the observed clearance values. There were in total 29 therapeutic proteins in this study with 75 observations. The number of observations with ≤30%, ≤50%, and >50% prediction error was 60 (80%), 72 (96%), and 3 (4%), respectively. Overall, the predicted clearance values of therapeutic proteins in children was good. The allometric method proposed in this manuscript can be used to select first-in-pediatric dose of therapeutic proteins in pediatric clinical trials.

Long-term outcome of renal function in children after stem cell transplantation measured by estimated glomerular filtration rate

BACKGROUND

Stem cell transplantation (SCT) outcomes have improved over the last three decades, with many patients being rescued with this treatment. However, improved outcomes have led to issues with long-term sequelae. One of these sequelae in children is renal dysfunction, an index of which is estimated using glomerular filtration rate (eGFR).

PROCEDURE

We retrospectively analyzed eGFR in 83 pediatric patients who received SCT. Data from all patients extended up to 12 months or more post SCT. The median follow-up time was 127.7 months (range 12.0-268.8 months).

RESULTS

Eighteen patients (21.7%) had low eGFR (<90 ml/min/1.73 m² ) post SCT. Cumulative incidence of low eGFR was 25.8 ± 2.0%. Nine (10.6%) patients had a low eGFR pre-SCT. However, pre- and post-SCT incidence of low eGFR were not correlated. Meanwhile, only two patients (2.4%) exhibited severe renal dysfunction, with eGFRs < 60 ml/min/1.73 m² . Independent risk factors for low eGFR were solid tumor and use of fludarabine. Moreover, age at SCT ≥ 7 years was also a long-term post-SCT risk factor for low eGFR in all patients.

CONCLUSION

Independent post-SCT long-term risk factors for low eGFR in children were solid tumor and use of fludarabine. Moreover, age at SCT ≥ 7 years was a post-SCT long-term risk factor for low eGFR across all patients.

Analysis of Hypokalemia as a Side Effect of Liposomal Amphotericin in Pediatric Patients

BACKGROUND

Liposomal amphotericin (L-AMB) is a widely used broad-spectrum antifungal drug. Although L-AMB demonstrates better safety compared with amphotericin, renal dysfunction and hypokalemia are well-known adverse effects of L-AMB.

METHOD

We analyzed 56 episodes in 40 children and adolescents who received L-AMB therapy to determine risk factors of hypokalemia.

RESULTS

Hypokalemia (<3.0 mEq/L continuously for more than 2 episodes) was observed in 31 of 56 episodes (55.4%). The median onset of hypokalemia was at 10 days on L-AMB (range, 3-54 days), and the median cumulative dose of L-AMB at occurrence of hypokalemia was 25 mg/kg (range, 10-167.5 mg/kg). None of the patients with hypokalemia had solid tumors, and they had significantly higher estimated glomerular filtration rates than those with normokalemia (P = 0.013). Seven of 25 (28.0%) patients in the normokalemia group and 1 of 31 (3.2%) patients in the hypokalemia group had eGFRs of <90 mL/min/1.73 m(2) (P = 0.017).

CONCLUSION

Although the reason for the association between estimated glomerular filtration rates and hypokalemia is unclear, assessing the estimated glomerular filtration rates before L-AMB administration may predict the development of hypokalemia.

Chronic kidney disease in children

Chronic kidney disease (CKD) is a major health problem worldwide. Although relatively uncommon in children, it can be a devastating illness with many long-term consequences. CKD presents unique features in childhood and may be considered, at least in part, as a stand-alone nosologic entity. Moreover, some typical features of paediatric CKD, such as the disease aetiology or cardiovascular complications, will not only influence the child's health, but also have long-term impact on the life of the adult that they will become. In this review we will focus on the unique issues of paediatric CKD, in terms of aetiology, clinical features and treatment. In addition, we will discuss factors related to CKD that start during childhood and require appropriate treatments in order to optimize health outcomes and transition to nephrologist management in adult life.