A systematic literature review and indirect comparison of iron isomaltoside and ferric carboxymaltose in iron deficiency anemia after failure or intolerance of oral iron treatment

OBJECTIVES: The efficacy of oral iron in treating iron deficiency anemia (IDA) can be limited by poor gastrointestinal (GI) absorption and adverse GI symptoms; intravenous (IV) iron is a well-established alternative. The present study compared the efficacy of two IV iron formulations in patients with IDA: iron isomaltoside (IIM) and ferric carboxymaltose (FCM).

METHODS: A systematic literature review (SLR) was conducted to identify randomized controlled trials (RCTs) of IIM and FCM in patients with IDA. An adjusted indirect treatment comparison (ITC) of IIM and FCM was then conducted to evaluate differences in change from baseline hemoglobin and the proportion of patients achieving a clinically-relevant response.

RESULTS: The SLR identified no completed RCTs of IIM versus FCM, 5 RCTs of IIM (4 versus oral iron and 1 versus iron sucrose), and 14 RCTs of FCM (11 versus oral iron and 3 versus iron sucrose). In an ITC via iron sucrose, IIM resulted in a significantly larger increase from baseline hemoglobin with a mean difference of +0.249 g/dL with IIM relative to FCM, but there was no significant difference in the proportion of patients with a clinically-relevant response.

CONCLUSIONS: IIM resulted in a larger increase from baseline hemoglobin than FCM in patients with IDA, but with no difference in the proportion of patients responding. Studies comparing IIM and FCM directly would be needed to confirm these findings.