It is proposed that the current development paradigm for biosimilars (‘totality of evidence’, ToE), which was modeled on the development of novel drugs, should be replaced in most cases by a more efficient paradigm (‘confirmation of sufficient likeness’, CSL) that emphasizes analytical likeness between a biosimilar and its reference but does not generally require comparator bridging studies, in vivo nonclinical studies or clinical equivalence studies.

This proposal is supported by evidence from the record of marketing applications for biosimilars in the European Union (EU), the United States (US), Canada, and Australia showing that no biosimilar that has been found to be highly similar to its reference by both analytical and human pharmacokinetic studies has ever failed to be approved because it was found not to be clinically equivalent to its reference in a powered study.

The implications of the data and the proposal are discussed in terms of the urgent societal need for removal of unnecessary barriers to entry to the global biosimilars market without a loss of product quality. It is concluded that the improvement in development efficiency that would be permitted by CSL would strongly support biosimilars as a therapeutic intervention.