An overview of the efficacy and safety of novel erythropoiesis stimulating protein (NESP).

Novel erythropoiesis stimulating protein (NESP, also known as darbepoetin alfa) is a molecule that stimulates erythropoiesis by the same mechanism as both native and recombinant human erythropoietin (rHuEPO). The extra sialic residues on NESP, however, allow it to be more stable in vivo with a 2- to 3-fold longer elimination half-life. Thus, following intravenous administration, the mean elimination half-life of NESP is 25.3 vs 8.5 h for rHuEPO. After subcutaneous administration, the mean terminal half-life for NESP is 48.8 h. The mean bioavailability of NESP after subcutaneous administration is approximately 37%, similar to that reported for rHuEPO. The pharmacokinetic data suggested that patients with renal anaemia would require less frequent dosing with NESP than with rHuEPO. NESP 0.45 microg/kg administered once weekly either intravenously or subcutaneously has been evaluated for the correction of chronic renal failure (CRF)-associated anaemia. The study population included CRF patients not receiving dialysis, along with those on haemodialysis or peritoneal dialysis. In patients who are rHuEPO-naïve, NESP has a similar effect in correcting the anaemia as is seen with rHuEPO, but with less frequent dosing. Similarly, in patients previously receiving rHuEPO, NESP (whether administered intravenously or subcutaneously) is as effective as rHuEPO treatment for maintaining haemoglobin concentration when administered at a reduced frequency (i.e. either once weekly or once every other week). NESP is well tolerated, adverse effects are similar to those seen with rHuEPO, and no antibodies have been detected in >1500 patients exposed to NESP thus far.