The Use of Concomitant Immunomodulators with Adalimumab Therapy in Pediatric Crohn’s Disease

Objectives: Adalimumab is an effective treatment for Crohn’s disease but antibody development may cause loss of response. Concomitant use of an immunomodulator reduces the development of antibodies. We performed a 5-year cross-sectional study of variation in use of adalimumab and concomitant therapy in a large pediatric population. Methods: We identified patients with Crohn’s disesae aged <18 years in the Improve Care Now registry who received adalimumab between June 2010 through May 2015, and determined the rates of treatment with adalimumab and concomitant therapy with thiopurine or methotrexate, including variation by age, sex, geographical region and annual change. Chi-square tests compared percentages and the Cochran Armitage Trend Test tested percentages over time and across age groups. Results: Of 7,271 patients, adalimumab treatment occurred in 1,009 (14%), more likely with increasing age ( p<0.001), in females (p<0.001), and in the West than the Northeast US (p<0.001). From year 1 to year 5, the use of adalimumab increased from 7% to 13% (p<0.001) and concomitant therapy increased from 25% to 47% (p<0.001). Of patients treated with adalimumab, 47% received concomitant therapy with thiopourine (19%) or methotrexate (28%). Concomitant therapy occurred more commonly in younger patients (p<0.01) but frequencies by sex were not significantly different (p=0.17). Conclusions: In pediatric Crohn’s disease there is increasing use of both adalimumab and concomitant therapy, including both thiopurine and methotrexate, with significant variation by age, sex and region of the US. Further study is needed to determine the effectiveness of and indications for concomitant therapy with adalimumab treatment.