The continuum of comparability extends to biosimilarity: how much is enough and what clinical data are necessary?

Experts debate the clinical evidence standards needed to approve major manufacturing changes for biologics, biosimilars, and interchangeable biosimilars. As sponsors consider their development plans, the resource investment required to develop an analytically highly similar candidate must be balanced by regulatory relief for the clinical studies required to achieve the necessary indications for the marketed product. This article discusses biosimilarity and comparability as related scientific and regulatory concepts and the usefulness of clinical data for both.