FDA issues warning on over-use of ESAs: Amgen hardest hit by the news

The US Food and Drug Administration has issued a public health advisory outlining strengthened product labeling on erythropoeisis-stimulating agents (ESAs), widely-used drugs for the treatment of anemia. The safety update affects Aranesp (darbepoetin alfa) and Epogen (epoetin alfa), both made by Amgen, as well as Johnson & Johnson's Procrit (epoetin alfa). All three drugs had combined US sales of $10.0 billion in 2006, according to IMS Health.

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. The agency and drugmakers have agreed on new labeling that includes updated warnings, a new black box alert and modifications to the dosing instructions.

The boxed warning advises physicians to monitor red blood cell levels (hemoglobin) and to adjust the ESA dose to maintain the lowest level needed to avoid the need for blood transfusions, advising physicians to carefully weigh the risks of ESAs against transfusion risks.