Pharmacological action – hematopoietic.
Darbepoetin alfa stimulates erythropoiesis by the same mechanism as endogenous erythropoietin. Darbepoetin alfa contains 5 N-linked carbohydrate chains, whereas the endogenous hormone and recombinant human erythropoietin (rhEPO) have only three chains. The additional sugar residues, from a molecular point of view, do not differ from those present in the endogenous hormone. Due to the increased carbohydrate content, darbepoetin alfa has a longer half-life compared to rhEPO and consequently higher activity in vivo. Despite these changes in molecular structure, darbepoetin alfa retains a very narrow specificity for the erythropoietin receptor.
Erythropoietin is a growth factor that primarily stimulates the production of red blood cells. Erythropoietin receptors can be expressed on the surface of various tumor cells.