Ferric carboxymaltose versus ferrous fumarate in anemic children with inflammatory bowel disease: the POPEYE randomized controlled clinical trial

Objective: To determine whether intravenous (IV) or oral iron suppletion is superior in improving physical fitness in anemic children with inflammatory bowel disease (IBD). Study design: We conducted a clinical trial at 11 centers. Children aged 8-18 with IBD and anemia (defined as hemoglobin [Hb] z-score < −2) were randomly assigned to a single IV dose of ferric carboxymaltose or 12 weeks of oral ferrous fumarate. Primary end point was the change in 6-minute walking distance (6MWD) from baseline, expressed as z-score. Secondary outcome was a change in Hb z-score from baseline. Results: We randomized 64 patients (33 IV iron and 31 oral iron) and followed them for 6 months. One month after the start of iron therapy, the 6MWD z-score of patients in the IV group had increased by 0.71 compared with −0.11 in the oral group (P =.01). At 3- and 6-month follow-ups, no significant differences in 6MWD z-scores were observed. Hb z-scores gradually increased in both groups and the rate of increase was not different between groups at 1, 3, and 6 months after initiation of iron therapy (overall P =.97). Conclusion: In this trial involving anemic children with IBD, a single dose of IV ferric carboxymaltose was superior to oral ferrous fumarate with respect to quick improvement of physical fitness. At 3 and 6 months after initiation of therapy, no differences were discovered between oral and IV therapies. The increase of Hb over time was comparable in both treatment groups. Trial registration: NTR4487 [Netherlands Trial Registry].