Efficacy and safety of ferric carboxymaltose in patients with inflammatory bowel disease

Iron deficiency anemia (IDA) is a prevalent complication in patients with inflammatory bowel disease (IBD). Ferric carboxymaltose (FCM) is a new intravenous iron formation that has been available for IDA in Japan since 2020. The present study aimed to investigate the efficacy and safety of FCM in patients with IBD and IDA. This single-center retrospective study included 41 patients with IBD treated with FCM at our hospital from September 2020 to June 2023. The FCM administered dose was 500mg in 28 patients, 1000mg in 7 patients, and >1500mg in 6 patients. The median hemoglobin level improved from 9.8g/dL to 11.8g/dL at 16 weeks after the first FCM administration during the study period. Median change in hemoglobin levels 16 weeks after the first FCM dose did not significantly differ between patients with low C-reactive protein (CRP) levels (CRP ≤0.5mg/dL;n=31) and those with high CRP levels (CRP >0.5mg/dL;n=10) (2.2g/dL vs. 1.7g/dL, p=0.94). Adverse events were observed in 6 patients, including hypophosphatemia in 2 (4.9%) and osteomalacia in 1 (2.4%). FCM administration in patients with IBD is expected to improve anemia even with fewer administrations.