Immunogenicity and Biosimilars

Gillian Woollett, MA, DPhil: You introduced the term immunogenicity. Now, I always like to remember that with vaccines, immunogenicity is good. However, in the context of biosimilars, we’ve had this flag that somehow immunogenicity is bad. And I think what’s evolved is immunogenicity can indeed compromise the efficacy of some of these products over time, particularly perhaps in the immunology space of some of these chronic diseases such as rheumatoid arthritis.

However, that can be intrinsic to the molecule itself that you’re matching and a biosimilar is going to be essentially equally as bad, as well as just as good as the reference product. We’re doing comparative immunogenicity in these limited studies. We’ve got the data from Europe in which we’ve seen that in real-world use, the patterns match and they’re the same. So really, is there any particular concern with immunogenicity and biosimilars that physicians, patients, providers, anybody should be concerned by, or is it just something we monitor?

Carlos Sattler, MD: I’ll start and then I’ll ask my colleagues to opine. I think it’s important to evaluate immunogenicity. But as you mentioned, Gillian, the goal here is to demonstrate that the immunogenicity characteristics or the immunogenicity or immune response of the biosimilar is equivalent or matches what you would expect in the reference product. Some biologics are more immunogenic than others. There are more complex biologics. Some of the monoclonals are more immunogenic than the simpler biologics. And amongst the monoclonals, some are more immunogenic than others. But again, what we’re trying to demonstrate here is that there is no difference in the immunogenicity profile of the biosimilar and the reference product.

We look at this in all of the clinical studies, whether they be human volunteer pharmacokinetic studies or efficacy and safety studies, phase 3 confirmatory studies in patients. And then this is evaluated also through pharmacovigilance and other means.

And again, I just want to emphasize that in Europe, where biosimilars have been available for over 10 years and millions of patients have received them and there is experience so far, there’s been no difference. And there are also a series of studies now that have shown that there is really no difference in the immunogenicity profile comparing a biosimilar to a reference product.