Biosimilar epoetin zeta: extrapolation of indications and real world utilization experience

There is an essential need for clinicians to understand the development and approval process of biosimilars. Extrapolation of efficacy and safety data from one indication to another may be considered by a comprehensive comparability program including safety, efficacy and immunogenicity, which detect potentially clinically relevant differences.

This article specifically discusses the approval of epoetin zeta (Retacrit™, Hospira, a Pfizer company) and the EMA reasoning for extrapolation of indications. Additionally, the results of the ongoing utilization surveillance program that was approved in 2007 and has analyzed over 120 million patient days of epoetin zeta treatment are presented.

At the time of approval, uncertainty of safety and efficacy is much less for biosimilars than for new innovative products. Approval of indications based on extrapolation of data is based on sound and objective scientific criteria and a logical consequence of the biosimilar concept that has been successfully implemented in the European Union. Biosimilar epoetin has been used extensively in patients in Europe for nine years. Following a review of the known risks and ADR information received in almost 120 million patient-days' worth of experience, the risks associated with treatment with epoetin zeta remain similar to those of the reference product.