Hypophosphataemia following ferric derisomaltose and ferric carboxymaltose in patients with iron deficiency anaemia due to inflammatory bowel disease (PHOSPHARE-IBD): a randomised clinical trial

ObjectiveIntravenous iron—a common treatment for anaemia and iron deficiency due to inflammatory bowel disease (IBD)—can cause hypophosphataemia. This trial compared the incidence of hypophosphataemia after treatment with ferric carboxymaltose (FCM) or ferric derisomaltose (FDI).DesignThis randomised, double-blind, clinical trial was conducted at 20 outpatient hospital clinics in Europe (Austria, Denmark, Germany, Sweden, UK). Adults with IBD and iron deficiency anaemia (IDA) were randomised 1:1 to receive FCM or FDI at baseline and at Day 35 using identical haemoglobin- and weight-based dosing regimens. The primary outcome was the incidence of hypophosphataemia (serum phosphate ResultsA total of 156 patients were screened; 97 (49 FDI, 48 FCM) were included and treated. Incident hypophosphataemia occurred in 8.3% (4/48) FDI-treated patients and in 51.0% (25/49) FCM-treated patients (adjusted risk difference: −42.8% (95% CI –57.1% to –24.6%) pConclusionDespite comparably effective treatment of IDA, FCM caused a significantly higher rate of hypophosphataemia than FDI. Further studies are needed to address the longer-term clinical consequences of hypophosphataemia and to investigate mechanisms underpinning the differential effects of FCM and FDI on patient-reported fatigue.