Amanda Forys, MSPH: Let’s talk a little bit more about the FDA. A recent paper argued that bridging studies are redundant and should not be required in the clinical development of biosimilars. What potential challenges could be associated with using a single global reference product?
Molly Burich, MS: As Dr Worthing mentioned, it’s a great question. Reference products, in a lot of ways, are biosimilar to themselves. Your product that was created in 1998 looks very different than what’s being manufactured in 2017. I think that the FDA, including bridging studies between the United States, the European Union product, and the biosimilar is really just trying to ensure that any differences (that would be natural because of the process of these) are accounted for, clinically, and are reflected in the clinical data of the product. It’s certainly possible that the agency’s thinking evolves as the biosimilar pathway evolves.
For now, I think the bridging study that’s required makes a lot of sense to, again, build that confidence in physicians who will write prescriptions for biosimilars, payers who will potentially require them, and patients who ultimately take them and want to make sure they’re getting a high-quality product that’s not going to create any issues with their disease.
Ha Kung Wong, JD: Yes, I have to agree with that. I’ll just say that biological products, with different manufacturing sites and, of course, post-approval changes in manufacturing (and this is something that Angus and Molly mentioned as well), there is some product drift. There can be some issues there. You don’t want to have differences that emerge in the critical quality attributes of the product. So, I agree. It definitely makes sense the way it is.