An Efficient Development Paradigm for Biosimilars.

The current development paradigm for biosimilars required by regulators in highly regulated jurisdictions is derived from the development of novel drugs and is unnecessarily burdensome and inefficient. It requires the accumulation of data from analytical, nonclinical (including in vivo studies in some jurisdictions), and clinical studies (including powered efficacy studies in most cases); this paradigm is known as 'totality of evidence' (ToE) and does not admit a conclusion of biosimilarity from analytical data alone. The record of biosimilar approvals in these jurisdictions shows that no biosimilar candidate that has been found highly similar to its reference in analytical and pharmacokinetic studies has failed to be approved. We propose a new paradigm ('confirmation of sufficient likeness', CSL) that emphasizes the demonstration of analytical resemblance between the biosimilar candidate and its reference, and permits the conclusion of biosimilarity upon this basis. CSL does not entail bridging studies between reference products, in vivo nonclinical studies, or powered efficacy studies and is, therefore, substantially more efficient than ToE while maintaining equivalent scientific rigor. Such efficiency will contribute to the attractiveness as well as the sustainability of biosimilars as a therapeutic modality.