The PTAB recently canceled the University of Pennsylvania’s U.S. Patent No. 7,625,558, a potentially fatal blow to the University’s suit against Eli Lilly and Company alleging its cancer therapeutic Erbitux® (centuximab) infringes the patent.  Eli Lilly and Co. v. Trustees of the Univ. of Penn., Case IPR2016-00458 (July 13, 2017). The PTAB’s decision resolved testimony from the parties’ competing expert witnesses in favor of the Petitioner (Eli Lilly and Company), thus highlighting how the PTAB’s scientific acumen can be leveraged to effectively to short-circuit an otherwise expensive and time-consuming lawsuit.

Erbitux® is the tradename of a monoclonal antibody (cetuximab) that binds to and inhibits signaling through epidermal growth factor receptor (EGFR). In the district court, Trustees of the University of Pennsylvania v. Eli Lilly and Company, No. 2:15-cv-06133-RK (E.D. Penn.), the Patent Owner alleged indirect infringement of various claims of U.S. Patent No. 7,625,558, based, at least in part, on Erbitux® label language relating to administration regimens used in conjunction with radiation therapy.  Interestingly, the district court held a subset of the asserted claims are invalid under 35 U.S.C. § 112, ¶ 5, for being improper multiple dependent claims.  Petitioner successfully petitioned the PTAB to review (in an IPR) and cancel the remaining asserted claims as being obvious, and obtained a stay in the related lawsuit during the pendency of the IPR.

The parties relied heavily on expert testimony during the IPR.  According to the Petitioner, the art disclosed administration of an anti-EGFR antibody in mice with certain tumors in combination with radiation therapy and suggested that pre-treatment with the antibody before radiation exposure enhanced the therapeutic effect.  In response, the Patent Owner submitted expert declarations arguing, for example, that the effect of the combination therapy would be unpredictable in view of art relating to small molecule therapeutics and because the mechanism of action of the prior antibody was unclear.  The PTAB found that the Petitioner had provided substantial evidence in support of the obviousness challenge, which the Patent Owner’s expert did not persuasively rebut.  For instance, the Patent Owner’s expert relied on evidence that lacked specific data relating to the contested issue or was based on a small molecule, which the PTAB considered to be distinct from an antibody-based therapeutic.

The Patent Owner challenged the credibility of Petitioner’s experts as lacking, for example, “the knowledge required to opine as to a skilled artisan” under Petitioner’s definition of “one of ordinary skill in the art” and lacking understanding of “inherency” as used in patent law.  Dismissing that challenge, the PTAB noted that the Patent Owner did not cite any legal authority for the proposition that an expert witness must be a “person skilled in the art” or understand patent law terms of art.  The Petitioner’s argument that “A person of ordinary skill is an objective lens through which the Board evaluates obviousness and there is no requirement that a skilled artisan, or experts opining on the views of a skilled artisan, is limited to one person” seemed to resonate with the Board.

The decision is a reminder that expert testimony is most effective when supported by specific evidence closely related to the technology at issue; here, teachings in the prior art relating to small molecule therapeutics were not considered as relevant to large molecule therapeutics.  This proceeding also illustrates an effective use of IPR to cut short a more expensive and time-consuming lawsuit.  Although the Patent Owner may request rehearing and/or appeal the final written decision, for now it appears that the Patent Owner’s lawsuit is in peril and the PTAB cleared at least one potential patent hurdle for companies developing centuximab biosimilars.