Not So Different: Should Biosimilar Variations Be Concerning?

Although the European Union has been in the biosimilars game longer than the United States, both are considered leaders in biosimilar use. Generics were the first copycat drugs, however, there are lessons to be learned from this experience. But biologics, which are made from living organisms, are not as simple to copy as generics are. There will be minute differences between biosimilars and originator biologics, and there will even be small differences between different batches of the same originator biologic. We now have reliable tests for determining whether these differences are clinically significant or not. But what does our experience so far with biosimilars and originators tell us about these differences?
We sat down with Paul Cornes, BM, BCH, MA, MRCP, FRCR, a consultant oncologist and biosimilars expert who was part of the team that developed and presented evidence to the FDA for the first successfully approved US biosimilar (filgrastim; Sandoz). Paul helped explain these is