Epoetin alfa: into the new millennium.

ABSTRACT

First used successfully to correct the anemia associated with chronic renal failure, epoetin alfa has been shown to be highly effective in many patients with either hematologic or nonhematologic malignancies. Multiple studies have demonstrated effective response rates, with increases in hemoglobin concentration and reduction or elimination of transfusion requirements in up to 75% or 80% in such patients. Nevertheless, as clinical experience has grown, several issues have arisen. First, not all cancer patients respond to epoetin alfa and, consequently, it is important to identify those patients most likely to respond to make early clinical decisions regarding dose adjustment or drug withdrawal. Second, experience in patients with renal failure has revealed a state of "functional iron deficiency" and, thus, highlighted the importance of iron supplementation to optimize the response to epoetin alfa. Does "functional iron deficiency" complicate epoetin alfa therapy of patients with the anemia of cancer, and could such patients benefit from iron supplementation? Finally, some hematologic malignancies, especially myelodysplastic syndromes, can be resistant to epoetin alfa monotherapy. Can the effective response rates in such patients be improved by combining epoetin alfa therapy with the administration of other hematopoietic growth factors? Epoetin alfa has made substantial contributions to the care of patients with cancer and, with time, additional uses for this very valuable drug will become apparent.