Understanding Real-World Biologic Maintenance Dosing Patterns Among Pediatric Ulcerative Colitis and Crohn’s Disease Patients

Abstract

Objectives To assess the initial and long-term maintenance dosing of biologic medications in pediatric UC and CD patients, using data in the ICN registry. Methods Pediatric patients (2–17 years) in the US who were diagnosed with UC or CD between June 1, 2013 and December 31, 2019, who, after enrollment in the ICN registry, initiated a biologic (adalimumab, infliximab, certolizumab, golimumab, ustekinumab, vedolizumab, and natalizumab) and were actively followed for at least 12 months after first maintenance dose were included in this study. Descriptive statistics of baseline patient demographics were summarized for the overall Inflammatory Bowel Disease (IBD) patient population and separately for UC and CD. Biologic maintenance dosage was calculated for UC and CD patients who had data for both dose and weight for each biologic at the baseline visit (first maintenance dose), 1-year and 3-year time points. Results A total of 1,887 pediatric IBD patients (UC=350; CD=1,537) were included in this study. Patients had a mean age at diagnosis of 12.9 years (UC=13.1; CD=12.9), 57.1% were male (UC=48.9%; CD=59.0%), and 80.6% were White (UC=79.8%; CD=80.8%) (Table 1). Infliximab (77.0%) was the most commonly prescribed biologic for UC, followed by adalimumab (12.4%), vedolizumab (10.1%), certolizumab (0.3%), and ustekinumab (0.3%). Similarly, infliximab (80.6%) was the most commonly prescribed biologic for CD, followed by adalimumab (16.5%), vedolizumab (1.6%), ustekinumab (1.2%), and certolizumab (0.1%) (Table 2). At first maintenance dose, UC patients on infliximab were receiving a mean dose of 10.5mg/kg/8wk, patients on adalimumab (weight <40kg) were receiving a mean dose of 1.3mg/kg/2wk, patients on adalimumab (weight≥40kg) were receiving a mean dose of 0.8mg/kg/2wk, and patients on vedolizumab were receiving a mean dose of 6.9mg/kg/8wks. Mean dose of infliximab among UC patients increased from 10.5mg/kg/8wk at first maintenance dose to 11.8mg/kg/8wk at 1-year from first maintenance dose. At the first maintenance dose, CD patients on infliximab were receiving a mean dose of 8.1mg/kg/8wk, patients on adalimumab (weight <40kg) were receiving a mean dose of 1.1mg/kg/2wk, patients on adalimumab (weight ≥40kg) were receiving a mean dose of 0.8mg/kg/2wk, patients receiving vedolizumab were receiving a mean dose of 10.5mg/kg/8wks. Mean dose of infliximab among CD patients increased from 8.1mg/kg/8wk at first maintenance dose to 9.6mg/kg/8wk at 1-year from first maintenance dose. Conclusion These results highlight the biologic maintenance dose changes among pediatric UC and CD patients. TNF inhibitors remain the most commonly used class of biologic, but the doses being used are double the standard dosing guidelines. There is little evidence of dose reduction over time among pediatric UC and CD patients in the ICN registry.