Efficacy and safety of ferric carboxymaltose and other formulations in iron-deficient patients: a systematic review and network meta-analysis of randomised controlled trials

Background Iron deficiency is very common in a number of medical conditions. Ferric carboxymaltose is a new stable iron preparation that can be administered in single infusions over short periods of time. The aim of this study was to conduct a systematic review of randomised controlled trials (RCTs) regarding the efficacy and safety of the novel complex compared with other iron formulations. In addition, the feasibility of a network meta-analysis for indirect comparisons was investigated. Methods A systematic literature review was performed for published RCTs on the use of ferric carboxymaltose in iron deficiency between July and October 2014. Indirect comparisons were also addressed using terms referring to competing iron formulations. We further supported the qualitative results of the systematic review by a network meta-analysis that allows pooling the evidence around different intervention outcomes in the absence of trials involving a direct comparison. Results The initial search yielded 1027 citations, which was decreased to 21 studies eligible for inclusion in the review. Studies were heterogeneous in the number of patients randomised, iron deficiency-related conditions addressed, trial inclusion criteria, time horizon, treatment dosage and outcomes assessed. Six studies with the same time horizon (i.e. 6 weeks) were included in the network meta-analysis. Considering the differences between final and initial outcome values for each iron formulation, the mean difference of these differences (delta) was estimated for each couple of treatments involving ferric carboxymaltose. Significant improvements in serum ferritin (lg/l) were obtained with ferric carboxymaltose compared to oral iron (delta 172.8; 95 % CI 66.7–234.4) and in haemoglobin (g/dl) with respect to ferric gluconate (delta 0.6; 95 % CI 0.2–0.9), oral iron (delta 0.8; 95 % CI 0.6–0.9) and placebo (delta 2.1; 95 % CI 1.2–3.0). Conclusions All currently available intravenous iron preparations appear to be safe and effective, but ferric carboxymaltose seems to provide a better and quicker correction of haemoglobin and serum ferritin levels in irondeficient patients.