Comparability of biologics is a validated technical approach in routine use by sponsors and regulators worldwide.

Comparability assessments are enabled by systematic advances in four areas: clear and convergent guidelines for evaluation of potential changes to biologics; risk-based systems of weighting analytical data; progressive improvements in analytical methods; and advanced understanding of glycosylation and other post-translational modifications.

Regulators have not applied consistent evidentiary standards of comparability to the licensure of innovators’ biologics and biosimilars in new markets.

When a reference product has been approved in multiple markets, supported in each by some of the same clinical data, only a single full evaluation of biosimilarity is usually necessary, and the biosimilar is approvable in other markets by reliance upon the first evaluation.