Anti-TNFα treatment after surgical resection for Crohn's disease is effective despite previous pharmacodynamic failure

Background: The outcome of patients with Crohn's disease who failed anti-tumor necrosis factor alpha (anti-TNF alpha) therapy despite adequate serum drug levels (pharmacodynamic failure) is unclear. We aimed to assess such pediatric patients who underwent intestinal resection and were re-treated with the same anti-TNF alpha agent postoperatively. Methods: Pediatric patients with Crohn's disease who underwent intestinal resection and were treated with anti-TNF alpha agents postoperatively were assessed retrospectively. Patients were stratified to those with preoperative anti-TNF alpha pharmacodynamic failure and those with no preoperative antiTNF alpha treatment. Results: A total of 53 children were included, 18 with pharmacodynamic failure and 35 controls. Median age at intestinal resection was 14.8 years with 23 (43%) girls. The median time from intestinal resection to anti-TNF alpha initiation was 8 months (interquartile range 4-14 months). At the time of postoperative anti-TNF alpha initiation there were no differences in clinical, laboratory, and anthropometric measures between groups. Similar proportions of patients from both groups were in clinical remission on anti-TNF alpha treatment after 12 months and at the end of follow-up (1.8 years, interquartile range, 1-2.9 years): 89% versus 88.5% and 83% versus 80% for pharmacodynamic failure patients and controls, respectively; P = 0.9. No significant differences were observed at 14 weeks and 12 months of postoperative anti-TNF alpha treatment including endoscopic remission rate and fecal calprotectin. Both groups significantly improved all measures during postoperative anti-TNF alpha treatment. Conclusions: Pediatric patients with Crohn's disease who failed anti-TNF alpha therapy despite adequate drug levels and underwent intestinal resection can be re-treated with the same agent for postoperative recurrence with high success rate similar to that of anti-TNF alpha naive patients