The search for biosimilars and biobetters.

There has been an increasing trend toward the approval of biosimilars in the USA and the EU. The regulatory requirements for demonstration of bioequivalence with comparator and reference products are now better understood. The original goal of legislation to approve biosimilars through a fast-track process that would lead to more competition and price reductions is starting to be realized. This article updates the current list of approved biosimilars in the USA and the EU. Data are presented that outline products in development, and we discuss some of the hurdles for new entries into the market place. The availability of reference data for comparator products has been a major obstacle to drug development, forcing companies to perform their own side-by-side comparison studies, or pursue new drug development candidates as biobetters.