How safe are erythropoiesis-stimulating agents?
The year 2007 was a rough one for erythropoiesis-stimulating agents (ESAs). Increasing concerns about their safety were raised in important meta-analyses of previously published data, specifically, the possibility that these agents increase the risk of venous thromboembolic phenomenona and shorten survival. These trends were seen primarily in studies of cancer patients.1 Meanwhile, front-page headlines in The New York Times were unkind: “Doctors reaping millions for use of anemia drugs.”2 However, the signals came earlier than 2007.
THE RISE AND POSSIBLE FALL OF ESAs
1989—These costly drugs are introduced and start their ascent to becoming one of the most widely used drug classes, helped along by direct-to-consumer advertising. (In one ad, Grandpa can run after the grandchildren despite being on chemotherapy because he uses erythropoietin!)
2001—A study declares that the higher the hemoglobin level rises in response to ESAs, the better the quality of life. It also hints that these agents improve survival.3
2002—The American Society of Hematology/American Society of Clinical Oncology Practice Guideline Writing Committee reviews the medical literature, performs a systematic review, and recommends that patients with low-risk myelodysplasia and those on chemotherapy who become anemic (with a hemoglobin level approaching 10 g/dL) have the option of receiving ESAs to raise their hemoglobin and decrease the need for transfusion.4
2003—Henke et al5 report that anemic patients with head and neck cancer who underwent radiotherapy and received erythropoietin in a randomized study had poorer survival and progression-free survival.
2005—Leyland-Jones et al,6 in another randomized study, report that patients with metastatic breast cancer receiving first-line chemotherapy (most of whom were not anemic) had a higher mortality rate if they received epoetin alfa.
2006—The guideline authors meet again to start the process of writing an update. A meta-analysis shows the thromboembolic risk and survival problems in a more systematic way, covering multiple studies.7
2007—The Centers for Medicare and Medicaid Services cuts back the reimbursement for the use of erythropoietin. The US Food and Drug Administration (FDA) publishes a black box warning suggesting that any hemoglobin level greater than 12 g/dL would be detrimental to a patient. The Guideline Writing Committee works on its document with this backdrop of turmoil.
2008—The updated guidelines are published. They recommend continuing to use ESAs for patients with low-risk myelodysplasia, and as an option to raise hemoglobin levels and prevent the need for transfusion in cancer patients undergoing chemotherapy whose hemoglobin level falls to 10 g/dL or less.8 The document includes stronger language against the use of ESAs in patients with anemia from cancer who are not undergoing chemotherapy. Meanwhile, some editorialists have suggested that it may be time to abandon ESAs because these drugs may promote more rapid tumor growth or pose a prohibitive risk of thromboembolic disease.9,10
In mid-March 2008, after reviewing the most recent data, an FDA panel calls for new limits on the use of ESAs: cancer patients who are undergoing treatment that could cure their cancer should not receive them, and neither should patients with advanced breast cancer or head and neck cancer. Furthermore, the FDA panel stipulates that when doctors do prescribe these drugs, they should warn patients of the possible dangers and seek their informed consent.
