Erythropoietin: High Profile, High Scrutiny

Recombinant human erythropoietin has enjoyed a high profile status throughout its history in medicine. The isolation and purification of erythropoietin and the subsequent cloning of the humanprotein,followedbyclinicaltrialsdemonstratingthereversal of anemia in renal dialysis patients in the 1980s ushered in the era of biotechnology. 1 In the 1990s, randomized clinical trials demonstrated that recombinant human erythropoietin was also effectiveintreatmentofanemiaincancerpatientsreceivingchemotherapy. 2 Subsequent open label trials described the impact of erythropoietic therapy in patients with anemia related to cancer chemotherapy. 3-5 While these trials lacked a control group, the results were very high profile because of the thousands of patients treated. These data correlated the relationship, not only between rising hemoglobin and reduction in transfusion requirement, but also in defining the relationships between anemia, fatigue, and quality of life measures. 6 These results were further validated in a subsequent randomized placebo-controlled study. 7 These open label trials also were fundamental to defining the incremental improvement in quality of life measures with increasing hemoglobin levels in cancer chemotherapy patients, with an optimum hemoglobin level of 12 g/dL. 8 Based on these data and extensive