by Playfuls Staff |
9th March 2007
The US Food and Drug Administration released today, March 9, a statement announcing the strenghtening of safety-related information in the drugs darbepoetin alfa (Aranesp) and epoetin alfa[more] (Epogen and Procrit). They are both erythropoiesis-stimulating agents (ESAs), widely-used drugs for the treatment of anemia.
The FDA and their manufacturers have agreed upon revised product labeling that includes updated warnings, a new boxed warning, and modifications to the dosing instructions. In short, the reccomendations are such that a physician is instructed to use the minimum possible dosage to keep up the hemoglobin level above the need for a transfusion.
"The agency is in the process of re-evaluating the safety of Aranesp, Epogen, and Procrit on the basis of the results of recent clinical studies," said Steven Galson, M.D. director of FDA's Center for Drug Evaluation and Research.
"The new studies provide significant new information for both prescribers and patients, and the new information applies to all ESAs, which share the same mechanism of action. The safety of these products will be discussed when the Oncologic Drugs Advisory Committee (ODAC) meets in May and further revisions to the labeling may occur after that meeting."
The FDA had to take action after studies described an increased risk of death, blood clots, strokes, and heart attacks in patients with chronic kidney failure when ESAs were given at higher than recommended doses. In other studies, more rapid tumor growth occurred in patients with head and neck cancer who received these higher doses.
All three drugs involved are manufactured by Amgen Inc. of Thousand Oaks, California. Procrit is marketed and distributed by Ortho Biotech LP, a subsidiary of Johnson & Johnson. Aranesp is Amgen's best-selling drug, with sales of about $4.1 billion in 2006, with Epogen bringing in $2.5 billion.
ESAs are genetically engineered forms of the naturally occurring human protein, erythropoietin. Natural erythropoietin is made by the kidney and increases the number of red blood cells. All ESAs have the same mechanism of action. As a result, FDA believes these new concerns apply to all ESAs and is re-evaluating how to safely use this product class.
