Biosimilars-Emerging Role in Nephrology.

The Food and Drug Administration (FDA) defines a "biosimilar" agent as a biologic that is highly similar to the reference or originator biologic product notwithstanding minor differences in clinically inactive components with no clinically meaningful differences in terms of the safety, purity, and potency. The advantage of biosimilars is that they are usually about 15%-30% less expensive than the reference product, which results in system-wide cost savings and increased patient access. Because biologic drugs are produced by living organisms, they are by nature heterogeneous and identical copies cannot be made, unlike generic versions of small-molecule drugs. Proposed biosimilars must undergo a rigorous evaluation process to demonstrate a high degree of structural and functional similarity with the reference biologic. Once that is confirmed, a stepwise process of comparison with the reference agent with regard to animal trials, pharmacokinetics/pharmacodynamics, immunogenicity, and human efficacy/safety is conducted. The experience with biosimilars in other highly regulated markets where patent protection for originator biologics is not as robust as in the United States has been favorable in terms of safety, efficacy, and cost savings. An FDA approval pathway was created in 2009 to expedite the approval of biosimilars; as of early 2018 nine agents had been approved through that pathway, none in nephrology. The first United States biosimilar epoetin was approved on May 15, 2018, but does not have an interchangeability designation, meaning that prescribers must specifically write for the biosimilar product for patients to receive it. Given the unfamiliarity of biosimilars within the nephrology community it is recommended that educational programs be developed to address this unmet need and for research to be conducted addressing the perceptual, clinical, and economic effect of biosimilars on our patients.