Gillian Woollett, MA, DPhil: Creating a Paradigm Shift in Biosimilar Development

January 17, 2020

Gillian Woollett, MA, DPhil, senior vice president, Avalere Health, discusses how “confirmation of sufficient likeness" should replace “totality of evidence” in biosimilar development.


In biologics the whole question, [as] for biosimilars, has been whether they can be defined analytically. We now have the methods to define them sufficiently well that the question becomes, what else do you need? So our confirmation of sufficient lightness is based on the analytics, establishing that indeed, the two products you're comparing—the reference and the biosimilar candidate—are sufficiently alike, and we chose the new terminology so as not to imply a difference. And once you've got the confirmation, sufficient lightness analytically, then what our paper shows—and that'll be referenced—what our paper shows is that the biosimilars worldwide in US, Europe, Australia and Canada, if the PK [pharmacokinetic] matches, that product was going to be approved as biosimilar. So that then becomes the confirmation of sufficient likeness. And what we're asserting in the paper is there's no need for additional clinical studies, because they won't tell you anything. And if a clinical study won't tell you anything, it lacks scientific validity. Therefore, it lacks ethical validity. And it shouldn't be being done, and certainly not routinely.

We also would like to note that our paper, which was published in August [2019] in BioDrugs1, subsequently, the European regulators have published a paper, also in BioDrugs in September2, and they're coming to the same conclusions just based on European data. So we think there's definitely a case to be made here to revisit what you're doing, and therefore a new paradigm is entirely appropriate3 and we just like confirmation of sufficient lightness.


1. Webster CJ, Wong AC, Woollett GR. An efficient development paradigm for biosimilar BioDrugs. 2019;(33)603. doi: 10.1007/s40259-019-00371-4.

2. Wolff-Holz E, Tiitso K, Vleminckx C, Weise M. Evolution of the EU biosimilar framework: Past and future. BioDrugs. 2019;(33)621. doi: 10.1007/s40259-019-00377-y.

3. Vulto A. Delivering on the promise of biosimilars. BioDrugs. 2019;(33)599. doi: 10.1007/s40259-019-00388-9.

Related Content: