A Pooled Analysis of Serum Phosphate Measurements and Potential Hypophosphataemia Events in 45 Interventional Trials with Ferric Carboxymaltose

Ferric carboxymaltose (FCM) has been shown to achieve rapid replenishment of iron stores and correction of anaemia in various populations with iron deficiency. A decrease in serum phosphate (PO(4)(3−)) levels, which in most cases is asymptomatic, has been reported with IV iron preparations. Hypophosphataemia (HP) is a known adverse drug reaction with FCM. This post hoc pooled analysis investigates the frequency, duration, risk factors, and clinical signs of HP as reported in interventional clinical trials with FCM. Pooled data from subjects enrolled across 45 clinical trials in different therapy areas were included. A three-step adjudication process was utilised to identify adverse events of HP. Stratified analyses by therapy group and stepwise logistic regression analysis were used to identify predictors of HP. This pooled analysis confirms that FCM is associated with increased rates of serum PO(4)(3−) lowering, but mean serum PO(4)(3−) values were seen to recover at Week 4 and further recover at Week 8. Among all subjects receiving FCM therapy (n = 6879), 41.4% (n = 2847) reached a PO(4)(3−) nadir value <2.5 mg/dL at any point on study and 0.7% (n = 49) reached a nadir <1 mg/dL. Although gastroenterology and women’s health subjects were identified to be at higher risk, occurrence of severe HP (<1 mg/dL [0.3 mmol/L]) following FCM administration was not observed to be common among subjects in these studies. Furthermore, there was no correlation between laboratory serum PO(4)(3−) values and the occurrence of reported adverse events related to low PO(4)(3−) levels.