Robert Cerwinski: Recent Trends in PTAB Decisions on Biologics, Biosimilars

Robert Cerwinski, JD, Partner at Goodwin, discusses the “big 3” biologics for inter partes review: Herceptin, Rituxan, and Humira.


What are some recent trends in [Patent Trial and Appeal Board, PTAB] decisions concerning biologics and biosimilars?

We see that biosimilar manufacturers have really embraced the availability of [inter partes review, IPRs] as a mechanism. Well before the biosimilar applications are actually submitted to FDA, we see that biosimilar manufacturers are really trying to clear a path with key patents well before they actually get to FDA. That’s a definite trend that we see in biosimilars. We had expected that IPRs would be important to biosimilar manufacturers, given the sheer number of patents and the variety of patents that typically cover reference products, especially products like Humira where there is a veritable patent thicket protecting it, and indeed that’s what we’ve seen. Most of the IPRs that have been filed to date have really centered on 3 products: Herceptin, Rituxan, and Humira. So, 3 of the biggest biologics that are really amenable to biosimilar applications at this point. Over a dozen of IPRs have been filed with respect to each of these products and the patents that cover them. Those are the big 3 for IPRs.

In terms of what’s actually happening at the PTAB with these biologic-related IPRs, we see that the rate of success for petitioners has been somewhat lower than what we’ve observed for petitioners generally. It’s a complex area of technology and we’re seeing that the PTAB is being very careful and meticulous in its approach to institution decisions as well as its approach to final determinations. So we’re seeing a lower rate of institution for biosimilar-related IPRs than in general. For those petitions that are instituted, we’re seeing a somewhat lower rate of invalidation after final determination. And in terms of patents that fare better or worse, if you are a petitioner in the PTAB, we see that method-of-use patents, so patents that cover approved indications, institution is granted somewhat more often for those kinds of patents than for composition patents or formulation patents. The data set isn’t very large for this yet, but we do something of trend in that respect, and that holds true in final determinations as well; we see that the PTAB, at least currently, has been more willing to hold method-of-use patents invalid. I think we are also seeing—I use the word “meticulous”—I think the PTAB is really trying hard to get these petitions resolved correctly. They are being—I use the word “sticklers”—they are holding everybody to the rules and they are holding everybody to their burdens of proof in these petitions pretty rigorously.