Nanomedicines in the treatment of anemia in renal disease: focus on CERA (Continuous Erythropoietin Receptor Activator).

Anemia is a common complication of chronic kidney disease (CKD), with erythropoietin deficiency being the major contributing factor. The availability of erythropoiesis-stimulating agents (ESAs) has been a seminal advance in the treatment of anemia related to chronic kidney disease. Over the course of the last decade and a half, newer generations of ESAs have become available. The first-generation ESAs or epoetins have a relatively shorter half-life and have traditionally been administered up to 3 times per week intravenously or subcutaneously to maintain adequate hemoglobin (Hb) levels. At the turn of the century, darbepoetin alfa, a hyperglycosylated form, became available for clinical use. It conferred greater metabolic stability in vivo owing to two additional N-linked carbohydrate chains attached to the protein backbone and has a half-life 3 times longer than that of epoetin. Recently developed and undergoing phase III clinical trials is the third-generation ESA, Continuous Erythropoiesis Receptor Activator (CERA), which has a methoxy-polyethylene glycol polymer chain integrated and has a longer elimination half-life than the first- and second-generation ESAs. Its receptor binding characteristics also differ from those of previous ESAs. Its major advantage is that extended dosing intervals are possible in the management of anemia related to erythropoietin deficiency.