Cinacalcet studies in pediatric subjects with secondary hyperparathyroidism receiving dialysis

Safety and Efficacy of Cinacalcet in Children Aged Under 3 Years on Maintenance Dialysis

Introduction

Secondary hyperparathyroidism (sHPT) is particularly severe in rapidly growing infants in dialysis. Although cinacalcet is effective and licensed in dialysis in children aged >3 years, its efficacy and safety for children aged <3 years is unknown.

Methods

We identified 26 children aged <3 years who were on dialysis and treated with cinacalcet between 2009 and 2021 in 8 European pediatric centers.

Results

Median (interquartile range) age at the start of cinacalcet was 18 (interquartile range: 11-27) months, serum parathyroid hormone (PTH) was 792 (411-1397) pg/ml, corresponding to 11.6 (5.9-19.8) times the upper limit of normal (ULN). Serum calcium was 2.56 (2.43-2.75) mmol/l, and serum phosphate 1.47 (1.16-1.71) mmol/l. Serum 25-OH vitamin D (25-OHD) was 70 (60-89) nmol/l, 3 children were vitamin D deficient (<50 nmol/l). The initial cinacalcet dose was 0.4 (0.2-0.8) mg/kg/d and the maximum dose was 1.1 (0.6-1.2) mg/kg/d. The median follow-up under cinacalcet was 1.2 (0.7-2.0) years. PTH decreased to 4.3 (2.2-7.8) times the ULN after 6 months, to 2.0 (1.0-5.3) times ULN after 12 months, and to 1.6 (0.5-3.4) times thereafter (P = 0.017/0.003/<0.0001, log-transformed PTH). Seven of the 26 infants developed 10 hypocalcemic episodes <2.10 mmol/l. Oral calcium intake was 84% (66%-117%) of recommended nutrient intake at start, 100% (64%-142%) at 3 months and declined to 78% (65%-102%) at 12 months of therapy. Three children developed clinical signs of precocious puberty.

Conclusion

Cinacalcet efficiently controlled severe sHPT in children aged <3 years and was associated with hypocalcemic episodes (similar to what is observed in older children) and precious puberty, thereby mandating meticulous control of calcium (considering nutrition, supplementation, and dialysate) and endocrine changes.

Safety of cinacalcet in children and adolescents with chronic kidney disease-mineral bone disorder: systematic review and proportional meta-analysis of case series

BACKGROUND

Mineral and bone disease in children with chronic kidney disease can cause abnormalities in calcium, phosphorus, parathyroid hormone, and vitamin D and when left untreated can result in impaired growth, bone deformities, fractures, and vascular calcification. Cinacalcet is a calcimimetic widely used as a therapy to reduce parathyroid hormone levels in the adult population, with hypocalcemia among its side effects. The analysis of safety in the pediatric population is questioned due to the scarcity of randomized clinical trials in this group.

OBJECTIVE

To assess the onset of symptomatic hypocalcemia or other adverse events (serious or non-serious) with the use of cinacalcet in children and adolescents with mineral and bone disorder in chronic kidney disease.

DATA SOURCES AND STUDY ELIGIBILITY CRITERIA

The bibliographic search identified 2699 references from 1927 to August/2023 (57 LILACS, 44 Web of Science, 686 PubMed, 131 Cochrane, 1246 Scopus, 535 Embase). Four references were added from the bibliography of articles found and 12 references from the gray literature (Clinical Trials). Of the 77 studies analyzed in full, 68 were excluded because they did not meet the following criteria: population, types of studies, medication, publication types and 1 article that did not present results (gray literature).

PARTICIPANTS AND INTERVENTIONS

There were 149 patients aged 0-18 years old with Chronic Kidney Disease and mineral bone disorder who received cinacalcet.

STUDY APPRAISAL AND SYNTHESIS METHODS

Nine eligible studies were examined for study type, size, intervention, and reported outcomes.

RESULTS

There was an incidence of 0.2% of fatal adverse events and 16% of serious adverse events (p < 0.01 and I2 = 69%), in addition to 10.7% of hypocalcemia, totaling 45.7% of total adverse events.

LIMITATIONS

There was a bias in demographic information and clinical characteristics of patients in about 50% of the studies and the majority of the studies were case series.

CONCLUSIONS AND IMPLICATIONS OF KEY FINDINGS

If used in the pediatric population, the calcimimetic cinacalcet should be carefully monitored for serum calcium levels and attention to possible adverse events, especially in children under 50 months.

SYSTEMATIC REVIEW REGISTRATION NUMBER (PROSPERO REGISTER)

CRD42019132809.

Bone Disorders in Pediatric Chronic Kidney Disease: A Literature Review

Intense changes in mineral and bone metabolism are frequent in chronic kidney disease (CKD) and represent an important cause of morbidity and reduced quality of life. These disorders have conventionally been defined as renal osteodystrophy and classified based on bone biopsy, but due to a lack of bone biopsy data and validated radiological methods to evaluate bone morphology in children, it has been challenging to effectively assess renal osteodystrophy in pediatric CKD; the consequence has been the suboptimal management of bone disorders in children. CKD-mineral and bone disorder (CKD-MBD) is a new expression used to describe a systemic disorder of mineral and bone metabolism as a result of CKD. CKD-MBD is a triad of biochemical imbalances in calcium, phosphate, parathyroid hormone, and vitamin D; bone deformities and soft tissue calcification. This literature review aims to explore the pathogenesis, diagnostic approach, and treatment of CKD-MBD in children and the effects of renal osteodystrophy on growing skeleton, with a specific focus on the biological basis of this peculiar condition.

Chronic kidney disease in children: an update

Chronic kidney disease (CKD) is a major healthcare issue worldwide. However, the prevalence of pediatric CKD has never been systematically assessed and consistent information is lacking in this population. The current definition of CKD is based on glomerular filtration rate (GFR) and the extent of albuminuria. Given the physiological age-related modification of GFR in the first years of life, the definition of CKD is challenging per se in the pediatric population, resulting in high risk of underdiagnosis in this population, treatment delays and untailored clinical management. The advent and spreading of massive-parallel sequencing technology has prompted a profound revision of the epidemiology and the causes of CKD in children, supporting the hypothesis that CKD is much more frequent than currently reported in children and adolescents. This acquired knowledge will eventually converge in the identification of the molecular pathways and cellular response to damage, with new specific therapeutic targets to control disease progression and clinical features of children with CKD. In this review, we will focus on recent innovations in the field of pediatric CKD and in particular those where advances in knowledge have become available in the last years, with the aim of providing a new perspective on CKD in children and adolescents.

Development and validation of an LC-MS/MS method by one-step precipitation for cinacalcet in human plasma

A sensitive, convenient, rapid and economic liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed to determine cinacalcet concentration in human plasma. A stable isotope cinacalcet (cinacalcet-D₃) was selected as internal standard and the analytes were extracted from plasma samples by a one-step precipitation procedure. Chromatography separation was conducted on an Eclipse Plus C18 column by gradient elution with mobile phase of methanol-water-ammonium formate system at a constant flow rate of 0.6 mL/min. Mass spectrometric detection was conducted by multiple reaction monitoring using positive electrospray ionization. Cinacalcet concentrations in human plasma were determined over the concentration range of 0.1-50 ng/mL. The accuracies of lower limit of quantification (LLOQ) and quality control samples were all within the range of 85-115%, and the inter- and intra-batch precisions (CV%) were all within 15%. The average extraction recovery rates were 95.67-102.88%, and the quantification was not interfered by the matrix components. The validated method was successfully applied to determined cinacalcet concentrations in human plasma from secondary hyperparathyroidism patients.

Impact of Cinacalcet and Etelcalcetide on Bone Mineral and Cardiovascular Disease in Dialysis Patients

PURPOSES OF REVIEW

With chronic kidney disease (CKD) progression, secondary hyperparathyroidism (sHPT) and mineral and bone metabolism disease (MBD) almost inevitably develop and result in renal osteodystrophy and cardiovascular disease (CVD). Together with active vitamin D, calcimimetics are the main therapy for sHPT in CKD. This review provides an overview of the therapeutic effects of oral cinacalcet and intravenous etelcalcetide on CKD-MBD and vascular disease, with a focus on pediatric dialysis patients.

RECENT FINDINGS

Randomized controlled trials in adults and children demonstrate efficient lowering of parathyroid hormone (PTH) by the calcimimetics together with a reduction in serum calcium and phosphate when combined with low-dose active vitamin D, while therapy with active vitamin D analogs alone increases serum calcium and phosphate. Cinacalcet and etelcalcetide both improve bone formation and correct adynamic bone, i.e., have a direct bone anabolic effect. They decrease serum calciprotein particles, which are involved in endothelial dysfunction, atherogenesis, and vascular calcification. Clinical trials in adults suggest a modest slowing of the progression of cardiovascular calcification with cinacalcet. Calcimimetic agents represent a major pharmacological tool for improved control of CKD-MBD, by efficiently counteracting sHPT and allowing for better control of calcium/phosphate and bone homeostasis. Albeit definite evidence is lacking, the beneficial effects of calcimimetics on CVD are promising. Routine use of cinacalcet has been suggested in children.

Pediatric Chronic Kidney Disease

Chronic kidney disease (CKD) in children has a significant impact on morbidity, mortality, and quality of life. The degree of renal dysfunction should be calculated using pediatric-specific formulas and the degree of CKD staged; this allows for appropriate dosing of medications based on renal function and monitoring for progression and comorbid conditions including metabolic acidosis, bone disease, anemia, cardiovascular complications, malnutrition and electrolyte abnormalities, growth failure, and psychosocial issues. Treatment strategies include treating the underlying disease and using general renal protective measures. Effective management of these complex issues requires a specialized multidisciplinary team approach.

Bone Disease in CKD in Children

This manuscript discusses mineral and bone disorders of chronic kidney disease (MBD-CKD) in pediatric patients with special emphasis on the underlying pathophysiology, the causes and clinical profile of growth retardation, the alterations in the growth plate, the strategies to optimize growth and the medical recommendations for prevention and treatment.