What characterizes a biosimilar according to regulatory definitions?

A biosimilar is characterized by being highly similar to an already approved reference biologic product, demonstrating no clinically meaningful differences in terms of safety, purity, and potency. This means that while biosimilars may not be identical to their reference products—due to the inherent variability and complexity in the production of biologics—they must show that any differences from the reference do not have an impact on how they function in the body.

This concept of "no clinically meaningful differences" is essential, as it reassures healthcare providers and patients that the biosimilar can be used in place of the reference product without compromising efficacy or safety. The regulatory framework for biosimilars emphasizes the importance of extensive studies demonstrating similarity in attributes such as pharmacokinetics and immunogenicity, thus ensuring that patients receive similar therapeutic benefits.

In contrast, the other choices depict misunderstandings of what a biosimilar represents. A biosimilar is not exactly identical to the reference product, it is not a completely new and unrelated drug, and while biosimilars can often be priced lower than reference biologics, cost alone does not define their regulatory identity.