The Tortoise and the Hare: Evolving Regulatory Landscapes for Biosimilars.

Challenges in demonstrating interchangeability and safety, as well as the ongoing evolution of regulations governing biosimilars, have meant that the development of the biosimilars industry has not been, and will not be, a carbon copy of the generics industry. Complexity in the development process reduces the cost advantages for biosimilars that generics offer over originators. There has been a marked difference in the number of biosimilars approved by the European Medicines Agency (EMA) and US FDA due to a lack of consensus and the different rates of progress in establishing both law and stable evidence-based regulatory guidelines for biosimilars. In this review, we provide a précis of the history and status of the regulatory regimes in the USA and Europe. Included is an assessment of market and nonmarket factors that may continue to influence the development of the biosimilars industry.