Through the Looking Glass: The Evolution of Erythropoiesis-Stimulating Agent Use
March 22, 2010
The perception and reality of the clinical value of erythropoiesis-stimulating agents (ESAs) in cancer supportive care have undergone a dramatic transformation since their initial use in 1990. The perception of ESA value in patients has evolved from panacea to miscreant over a 2-decade period of laboratory research, clinical trial data, and postmarketing experience. Meanwhile, the real clinical benefits of ESAs have changed very little from those described in the joint American Society of Clinical Oncology/American Society of Hematology guidelines originally published in 2002. Even then, the value of initiation of ESAs was clear only in patients with hemoglobin values < 10 g/dL; quality-of-life measures produced inconsistent and, therefore, clinically inapplicable, results; and ESA use was shown to reduce the proportion of patients requiring red blood cell (RBC) transfusions by approximately 20%. The reality of ESA use that came to light following approval was increased mortality rates in certain populations, higher tumor progression and cancer recurrence rates, and more frequent and severe serious adverse effects including thromboembolism, stroke, and cardiovascular events.