Abstract
The principles of comparability assessments have been accepted globally as offering sensitive and reliable tools with which to evaluate potential changes to biologics that may arise either through processing changes or through the creation of a copy (biosimilar) by a different sponsor. The comparability approach has evolved through 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 post-translational modifications. Routine regulatory expectations for clinical equivalence data are being reevaluated, as they seldom contribute to the assessment of similarity. Similarly, we show that requirements to compare biosimilars and locally sourced versions of their reference products are of questionable scientific value and represent a double standard by comparison with the invariable acceptance of the clinical profiles of novel biologics without reference to their sources. The consistent application of evidentiary standards for comparability to all biologics offers an opportunity for regulators to curtail their own assessments of new biosimilars and instead to recognize comparability assessments made in another jurisdiction (reliance), thereby gaining important efficiencies in the regulatory review of biosimilars and improving the competitiveness of the biosimilars market. Such consistency can also enhance the confidence of all stakeholders, especially patients and their providers, in all biologics.