Darbepoetin alfa for chemotherapy-induced anemia: evolution to extended dosing intervals.

Anemia is a frequent problem in cancer patients, especially in those treated with chemotherapy, and has an important negative impact on quality of life. Red blood cell transfusions provide clear but rather temporary comfort. The development of erythropoietic stimulating agents (ESAs) led to a more durable anemia treatment. Darbepoetin alpha is a unique ESA with a long plasma half life, thereby suitable for administration with different dosing intervals. Apart from administration every week, darbepoetin alpha also proved to be efficient in reducing red blood cell transfusion rates and in improving health-related quality of life when administered at a dose of 500 microg once every 3 weeks. This is a convenient therapy schedule because it can be synchronized with the chemotherapy cycle in many patients. Recently, concerns have been raised about the long-term safety of ESAs, more specifically about their effect on survival. Available data must be interpreted with caution, but at present there is no clear evidence to support a negative effect on outcome with darbepoetin alpha therapy when used according to the guidelines for treatment of chemotherapy-induced anemia. Further studies focusing on survival as the primary end point are ongoing.