Impact of erythropoiesis-stimulating agent prescribing at an Asian cancer center, after release of safety advisories

Abstract

Background. Erythropoiesis-stimulating agents (ESAs) provide symptom relief and decrease blood transfusion support among patients with chemotherapy-induced anemia. However, due to increased cardiovascular events associated with off-labeled usage of ESAs, the FDA incorporated black box warnings in 2007 to include the following key points: (a) ESAs should be used only to treat anemia due to concomitant chemotherapy of a noncurative intent and (b) target hemogloblin level should not exceed 12 g/dL. Thus, this study was designed to compare the prescribing of epoetin alfa at National Cancer Centre Singapore before and after FDA black box updates. The secondary objective of this study was to evaluate the appropriateness of efficacy and toxicity monitoring of epoetin alfa. Methods. This was a retrospective, single-centered, drug utilization review. Patients who received at least one dose of epoetin alfa were included in this study. Utilization of epoetin alfa was segregated into two time periods: January 1, 2005 to October 15, 2007 (S1, Pre-safety advisories changes) and October 16, 2007 to December 10, 2009 (S2, Post-safety advisories changes). Results. A total of 171 patients were prescribed epoetin alfa at NCCS during the two time periods. However, only 139 patients were eligible for analysis, with 91 and 48 patients in S1 and S2 respectively. After safety advisory changes, there were more (18.2%) metastatic patients and fewer (19.1%) patients with cardiovascular co-morbidities who were prescribed epoetin alfa, the mean hemogloblin level when epoetin alfa was initiated was lowered by 0.46 g/dL, more (43%) dose adjustments were made for ‘excessive’ responders and more (40.7%) patients had fewer blood transfusions after epoetin alfa therapy ( p < 0.05). However, blood pressure control, iron studies, and supplementation did not improve ( p > 0.05). Conclusion. This study suggested that oncologists have generally adopted the new ESA safety warnings and adjusted prescribing habits.