New pharmacological concepts for the treatment of iron overload disorders

Imbalances of iron homeostasis cause frequent clinical syndromes. Iron deficiency affects almost 25% of the global population and approximately one billion people suffer from iron deficiency anaemia. Moreover, the anaemia of chronic disease, which develops primarily in subjects suffering from malignancies, infections and autoimmune disorders is pivotally caused by an iron-limited erythropoiesis, which arises from iron retention within cells of the reticulo endothelial system. In contrast, one of the most frequent inherited disorders in people of Northern-Western European origin is hereditary hemochromatosis (HH). HH leads to progressive iron overload in parenchymal organs with subsequent organ failure. In addition, secondary iron overload develops in patients receiving repetitive blood transfusion for the treatment of genetic hemoglobinopathies or for the correction of anaemia in cancer or myelodysplastic syndromes. Due to the discovery of new genes, our knowledge on the regulation of iron homeostasis has dramatically expanded which offers avenues for new treatment options. This is of importance, since some of these clinical syndromes (e.g. anaemia of chronic disease or secondary iron overload) are not sufficiently treatable with current medications (e.g. iron chelators, iron, erythropoietin) in many patients. In addition, some patients with iron deficiency face side effects from iron therapy or refuse phlebotomy for treatment of HH. Thus, new treatment strategies for iron metabolism disorders or improvement of existing concepts are necessary. This review discusses established, approaching and future putative treatment strategies and concepts for combating iron metabolism disorders.