Biosimilars IPRs: Any Lessons From PTAB Institution Decisions On Coherus Petitions?

May 2, 2018

In March, the PTAB denied institution of Coherus’s IPRs against Hoffman-LaRoche (2017-1916 and 2017-2066). Previously, however, the PTAB instituted Coherus’s early IPRs against Abbvie (2016-172, 2016-0188, and 2016-0189). Can any lessons be learned from the different outcomes in these cases?

Yes, but it’s not really a surprising one … Focus on claim language.

In the Abbvie petitions, the claims were directed to methods of reducing signs and symptoms in a patient with moderately to severely active rheumatoid arthritis comprising administering a human anti-TNFα antibody.

The PTAB determined that the preamble in the claims “gives life, meaning, and vitality to the claims only to the extent that it specifies the patient to whom the anti-TNFα antibody is administered.” In particular, the PTAB noted that “reducing the signs and symptoms of rheumatoid arthritis” merely recites an intended use, and that the claims do not require any specified level of efficacy.

These determinations were significant because Abbvie’s arguments against instituting the IPRs were “premised on a claim element which is not present – namely, some specified level of efficacy in the treatment.”

The PTAB went on to note that, given this lower level of efficacy required in the claims, “all that is required to show obviousness is a reasonable expectation of success, not conclusive proof of superior efficacy.”

Coherus focused on claim language and sufficiently demonstrated that the asserted art suggested the claimed methods. Accordingly, the PTAB instituted the IPRs.

In contrast, IPRs against Hoffman LaRoche were not instituted because Coherus did not focus on claim language and did not sufficiently demonstrate that the asserted art suggested the claimed subject matter.

The claims at issue in the Hoffman LaRoche petitions were directed to proteins including the extracellular region of an insoluble human TNF receptor and “all domains of the constant region of a human IgG heavy chain other than the first domain of the heavy chain constant region.”

The PTAB determined that the broadest reasonable interpretation of the phrase “all of the domains of the constant region ... other than the first domain of said constant region” means “all of the hinge, CH2,and CH3 domains.” Thus, any protein with less than all of the hinge domain of a human IgG (or IgG1) immunoglobulin heavy chain, even if functional, falls outside the scope of the claims.

However, Coherus did not sufficiently explain or demonstrate how the asserted art would result in proteins having the required regions, in particular the required hinge region, with the PTAB noting that “it is unclear what Petitioner considers to be the hinge.” Thus, Coherus did not adequately link its arguments to claim language, and the IPR petitions were denied.

So, despite the complexity of the factual issues involved in these petitions, the institution or denial of the petitions hinged on the relatively mundane issue of whether the petitions adequately linked the asserted art to the claimed subject matter.