The goal of a biosimilar development program is to demonstrate biosimilarity between a proposed biosimilar product and the reference product, not to independently establish the safety and efficacy of the biosimilar product.
While biosimilars and the reference biologic are both produced in living cells, they are not identical to one another―no more than different production lots of biologics are identical to one another. Regulators in major markets―the U.S., Europe, and Japan―have developed tailored approval pathways for biosimilars in anticipation of patent expirations on blockbuster biologic drugs, and demand for reliable, lower-cost alternatives.
Reference biologics and biosimilars are scrutinized through different lenses. With reference biologics, the regulatory emphasis is on the results of clinical trials to demonstrate safety and efficacy in a given indication. With biosimilars, the emphasis is on demonstrating there are no clinically meaningful differences from the reference drug in areas including safety, purity, or potency.
1 FDA recommends sponsors use a stepwise approach in developing evidence to support a demonstration of biosimilarity, ensuring that development at each step evaluate the extent to which there is residual uncertainty regarding a demonstration of biosimilarity between the proposed and reference product, and identify next steps to address that uncertainty