Patent protection for pharmaceuticals in the United States is very robust and perhaps there is no greater example than epoetin alfa. Since the approval of epoetin alfa by the Food and Drug Administration (FDA) in 1989, the developer, Amgen (Thousand Oaks, CA), has successfully defended its patent against competing agents, such as epoetin beta (Chugai-Upjohn, Rosemont, IL), epoetin delta (Shire, Lexington, MA), and methoxy polyethylene glycol-epoetin beta (CERA; Roche, Basel, Switzerland). The US patent on epoetin alfa expired in 2015, opening the way for competition by products other than Amgen’s own darbepoetin. The first non-Amgen erythropoiesis-stimulating agent (ESA) to enter the US market was CERA, which had previously been approved by the FDA as a new drug under a biologic license application 351(a). Drugs approved through the 351(a) pathway must undergo expensive clinical testing, the cost of which is ultimately passed on to the consumer. ESAs are biologic drugs, defined by the FDA as “a virus, therapeutic serum, toxin, antitoxin, blood, blood component or derivative, allergenic product, protein (except any chemically synthesized polypeptide), or analogous product . . . applicable to the prevention, treatment of cure of a disease or condition of human beings.”