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.

Chronic kidney disease remains as one of the major complications for individuals with diabetes and contributes to considerable morbidity. Individuals subjected to dialysis therapy, half of whom are diabetic, experience a mortality of ~20% per year. Understanding factors related to mortality remains a priority. Outside of dialysis units, A1C is unquestioned as the "gold standard" for glycemic control. In the recent past, however, there is evidence in large cohorts of diabetic dialysis patients that A1C at both the higher and lower levels was associated with mortality. Given the unique conditions associated with the metabolic dysregulation in dialysis patients, there is a critical need to identify accurate assays to monitor glycemic control to relate to cardiovascular endpoints. In this two-part point-counterpoint narrative, Drs. Freedman and Kalantar-Zadeh take opposing views on the utility of A1C in relation to cardiovascular disease and survival and as to consideration of use of other short-term markers in glycemia. In the narrative preceeding this counterpoint, Dr. Freedman suggests that glycated albumin may be the preferred glycemic marker in dialysis subjects. In the counterpoint narrative below, Dr. Kalantar-Zadeh defends the use of A1C as the unquestioned gold standard for glycemic management in dialysis subjects.