History of Erythropoiesis-Stimulating Agents, the Development of Biosimilars, and the Future of Anemia Treatment in Nephrology.

BACKGROUND Exogenous replacement of erythropoietin (EPO) by recombinant human EPO has been considered a standard of care for the treatment of anemia in patients with chronic kidney disease for more than 20 years. Genetically engineered biologic proteins derived from human, animal, or microorganism sources are a major area of growth in modern medical care, accounting for one-third of new drug approvals in the past decade. Despite benefit to patients, the use of biologics comes at a significant cost, representing one of the fastest growing segments of strained healthcare budgets around the world. SUMMARY Biosimilars, or biologic drugs that are designed to be highly similar to approved reference biologic drugs, have been available in Europe for more than 10 years with no unusual or unexpected effects compared to their reference biologics whose patents have expired. Given the success of the biosimilar approval pathway pioneered in Europe, it has served as a global reference for other regulatory authorities to establish and implement biosimilar licensure frameworks, including the United States (US), the largest pharmaceutical market in the world. Given 10 of the top 25 drugs sold in 2014 were biologics, and considering the rising costs of healthcare, biosimilars have the potential to become a significant part of the US market. Key Messages: For the nephrology community, the recent patent expiries for epoetin alfa (Epogen®, Amgen and Procrit®, Johnson & Johnson) have created the opportunity to develop biosimilar EPOs. And while no biosimilar in this therapeutic class is approved in the US, there are proposed biosimilars in development.