In IPR2016-00781, the PTAB denied institution on the grounds that the petitioner was estopped with respect to the claims of U.S. Patent No. 8,846,112 (“the ‘112 patent”). In an earlier proceeding brought by the petitioner, IPR2015-00529, the PTAB issued a Final Written Decision adjudicating all claims of the ‘112 patent.

During the prosecution of an application related to the ‘112 patent while that earlier IPR was pending, the PTO cited two prior art references, Greenough and Jaypee, as relevant to obviousness. Contending that these references were previously unknown and only recently discovered, the petitioner brought the IPR at issue. In support, the petitioner cited a report from the earlier invalidity search it had commissioned. The petitioner also explained that, after the earlier IPR was filed, it had intensified its efforts to generate prior art because it had been sued by the patent owner in district court.

The America Invents Act provides that a petitioner “may not request or maintain a proceeding before the Office with respect to that claim on any ground that the petitioner raised or reasonably could have raised during that inter partes review.” 35 U.S.C. § 315(e)(1). To support its analysis, the Board looked to the legislative history which “describes grounds that ‘reasonably could have been raised’ as encompassing ‘prior art which a skilled searcher conducting a diligent search reasonably could have been expected to discover.’” citing 157 Cong. Rec. S1375 (daily ed. Mar. 8, 2011) (statement of Sen. Kyl).

The Board was not persuaded by petitioner’s assertion of diligence because it was “predicated on a single search report by an unidentified searcher of indeterminate skill and experience listing a mere fifteen ‘exemplary’ search results.” Specifically, the petitioner failed to “identify the actual searcher, his or her skill level and experience in the field, [] why he or she searched using certain keywords and keyword combinations, or explain whether either Greenough or Jaypee were encompassed by the initial search results but not selected for the exemplary list.” In contrast, the patent owner put forth evidence showing that both references could be identified by searching Google Books with terms from the ‘112 patent specification. The Board also observed that the petitioner’s diligence argument was “at odds” with its assertion that one of skill in the art would have been motivated to look specifically to these two references to ascertain the subject matter of the ‘112 patent. As a result, the Board concluded that a skilled searcher would have been expected to discover Greenough and Jaypee in conducting a diligent search and declined to institute.

Practice Tip

To establish what grounds reasonably could have been raised in an earlier proceeding, a party should put forth persuasive evidence of what a skilled searcher’s diligent search would or would not have found. Such evidence could include an identification of the actual searcher, his or her skill level and experience, search strings and sources used, and search results obtained.

Praxair Dist., Inc. v. INO Therapeutics LLC, IPR2016-00781 (Aug. 25, 2016) (Paper 10).