What are biosimilars and why are they important?

19 August 2016

Professor Vibeke Strand (USA) answers some of the key questions about biosimilars and their use in rheumatoid arthritis and other immune-mediated inflammatory diseases

Hello I'm Alan Gibofsky from Hospital for Special Surgery in New York. I'm Vibeke Strand from Stanford University in Palo Alto, California and we're here today to talk a little bit about biosimilars for Rheumatology Education.

Vibeke what is a biosimilar? Well a biosimilar is meant to be a copy of a reference biologic agent, one that's already been approved and it's meant to be highly similar in terms of its structure and function immunogenicity, pharmacokinetics, and has very similar comparability in safety and equivalent in efficacy.

Tell our colleagues why biosimilars have become so important in rheumatology in 2016? Well I think they're so important because of the tremendous cost of the originator or reference products, particularly in in the United States. As an example, they've gone up in price since the original one was first approved in 1998, and how popular they are: we've got 22 of them approved by EMA in Europe, but we have 57 under review in the United States, when we only had our first biosimilar approved in 2015, and our second monoclonal antibody biosimilar in 2016.

I guess the more important thing to leave our colleagues with is: what does extrapolate ability or extrapolation mean? Because that seems to be one of the buzzwords around biosimilars today. I would agree, so I think when we had erythropoietin or we had GM-CSF or G-CSF, what we were thinking about is it is almost a single or two indications for those reference products. But we look at the TNF inhibitors for which we now have a biosimilar in the United States and we're looking at five or six different clinical indications and they're quite varied: rheumatoid arthritis and psoriatic arthritis might be quite similar, but then we look at psoriasis or we look at inflammatory bowel disease such as Crohn's disease or ulcerative colitis and there's been quite a bit of discussion about whether the mechanisms of action are actually the same across all these different diseases. So I think what we've learned and we are learning from biosimilars is that the mechanism of actions are actually quite similar across these different indications. Soluble TNF binding and neutralization, and binding of transmembrane TNF presumably are the major mechanisms of action even in IBD.

So wait are you saying that a biosimilar can be approved for an indication that it wasn't studied in? No it can't be approved for an indication it wasn't studied in, but it should be approved for all the indications for the reference product that has been approved for use. But that means that you have to show that the plausible mechanisms of action are actually inhibited in the same way by the biosimilar as by the reference product.

So do you think that biosimilars, when they come to the United States, or as we've seen them in other parts of the world, have actually fulfilled their promise of increasing access and decreasing costs? I can only hope so. I think we've seen in Canada that the biosimilar monoclonal infliximab is actually 50% of the cost of the reference product. We don't know what the cost savings will be in the United States but we do know the cost savings have been extensive in Europe, as much as a 72% discount.

So there you have it a brief overview of some important areas in our discussion about biosimilars. Stay tuned for more discussions and for other videos on this website. Thank you.