Balevic SJ, Becker ML, Gonzalez D, Funk RS. Low Etanercept Concentrations in Children With Obesity and Juvenile Idiopathic Arthritis.
J Pediatr Pharmacol Ther 2021;
26:809-814. [PMID:
34790070 DOI:
10.5863/1551-6776-26.8.809]
[Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Accepted: 01/14/2021] [Indexed: 11/11/2022]
Abstract
OBJECTIVE
To evaluate the impact of obesity on etanercept (ETN) drug exposure in children with juvenile idiopathic arthritis (JIA).
METHODS
We conducted a pilot, cross-sectional, observational study in a real-world cohort of children with JIA receiving ETN as standard of care from a single center. We analyzed the relationship between body size and ETN plasma concentrations, adjusting for dosage. Body size was analyzed as a continuous measure using weight and body mass index (BMI) percentiles and categorically using BMI percentile classifications according to the CDC guidelines.
RESULTS
We enrolled a total of 29 children. Each child provided one plasma sample for ETN concentration measurement, and all participants were receiving subcutaneous ETN dosed weekly. We observed that the ETN concentration normalized for dose decreased significantly as a function of weight (p = 0.004) and BMI percentile (p = 0.04). Similarly, we observed a progressive decline in mean and median dose-normalized concentrations across higher body size categories. Because of reaching maximum ETN dosage (50 mg), 7 of 8 children (87.5%) with obesity received a weight-based dosage < 0.8 mg/kg/dose.
CONCLUSIONS
We found that higher body weight and BMI percentile are significantly and negatively associated with ETN drug serum concentration, accounting for differences in dosing. Our data suggest that children who are obese may be routinely under-dosed using current dosing strategies. Inadequate dosing may increase the risk for therapeutic failure and long-term morbidity in a developing child. As a result, characterizing adequate drug exposure in children of all sizes is an important step toward precision dosing.
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