Ferric carboxymaltose significantly increased hypophosphataemia risk in IBD patients with IDA

A new study published in BMJ Gut found that, iron deficiency anaemia (IDA) treatment with ferric derisomaltose (FDI) and ferric carboxymaltose (FCM) was equally effective, while the latter dramatically increased the rate of hypophosphataemia.

Hypophosphataemia can be brought on by intravenous iron, a typical treatment for anaemia and iron shortage brought on by inflammatory bowel disease. In this study, the incidence of hypophosphataemia following ferric derisomaltose or ferric carbo therapy was studied.

20 outpatient hospital clinics throughout Europe participated in this randomised, double-blind clinical investigation (Austria, Denmark, Germany, Sweden, UK). Using the same haemoglobin- and weight-based dosage regimens, adults with IBD and IDA were randomly assigned 1:1 to receive FCM or FDI at baseline and at Day 35. The main result was the frequency of hypophosphataemia (serum phosphate 2.0 mg/dL) in the safety analysis set (all patients who received 1 dosage of study medication) at any point from baseline to Day 35. Measurements were made of patient-reported fatigue scores as well as indicators of mineral and bone homeostasis.

 The key findings of this study were;

1. 156 patients in all were screened; 97 (49 FDI, 48 FCM) were accepted and received treatment. 

8.3% (4/48) of patients receiving FDI experienced incident hypophosphataemia, whereas 51.0% (25/49) of patients receiving FCM experienced it.

2. Joth iron preparations fixed IDA. In both groups, patient-reported fatigue scores improved, though with FCM more gradually and to a smaller amount than FDI; a delayed reduction in fatigue was linked to a bigger decrease in phosphate concentration.

In conclusion, the PHOSPHARE-IBD experiment proved that hypophosphataemia is a prevalent adverse effect of FCM that is triggered by significant elevations in FGF23 rather than a class or dose impact of intravenous iron.

Reference: 

Zoller, H., Wolf, M., Blumenstein, I., Primas, C., Lindgren, S., Thomsen, L. L., Reinisch, W., & Iqbal, T. (2022). Hypophosphataemia following ferric derisomaltose and ferric carboxymaltose in patients with iron deficiency anaemia due to inflammatory bowel disease (PHOSPHARE-IBD): a randomised clinical trial. In Gut (p. gutjnl-2022-327897). BMJ. https://doi.org/10.1136/gutjnl-2022-327897