Invalidity Defenses Will Not Be Stricken at Pleading Stage Despite Defendant’s Earlier PGR Petition

Nov 12, 2019

Reading Time : 2 min

The defendant first challenged the patent by filing a PGR petition approximately eight months after the issuance of the patent. In its petition, the defendant only raised 35 U.S.C. Section 101 unpatentability grounds. The PGR proceeding concluded in a final written decision in which seven of the 20 challenged claims survived. Shortly afterwards, the patent owner filed the patent infringement action. The defendant’s answer included invalidity as an affirmative defense, and the patent owner moved to strike under Rule 12(f), arguing that the defendant was statutorily estopped from raising that defense by Section 325(e)(2).

The court first explained that Rule 12(f) allows for considerable discretion, but that when a defense raises a question of fact, the court must deny a motion to strike.

The court began its analysis by setting out the framework for the scope of the “reasonably could have raised” provision. First, the court explained that prior questions about instituted versus non-instituted grounds were effectively mooted by the Supreme Court’s decision in SAS Institute, Inc. v. Iancu, 138 S. Ct. 1348 (2018), and the Federal Circuit’s post-SAS decisions. Under current Patent Trial and Appeal Board (PTAB) practice, a petition must be either fully instituted or fully denied, and therefore any defense that is included as a ground in an instituted petition will qualify as having been raised during PGR review.

Next, the court turned to whether non-petitioned grounds are subject to estoppel. After surveying the differing rulings by various district courts, the court rejected the view that a petitioner was allowed to raise defenses that had not been included in a petition. The court reasoned that in order for “‘reasonably could have raised’ to have any meaning at all, [those words] must refer to the grounds that were not actually raised in the PGR petition, but reasonably could have been included.” The court outlined legislative history and public policy considerations in support of including non-petitioned defenses under the estoppel umbrella.

Finally, the court set out the standard for deciding whether a defendant “reasonably could have raised” a defense, again drawing on legislative history. The court ruled that “reasonably could have raised” “include[s] prior art that a petitioner actually knew about or that ‘a skilled searcher conducting a diligent search reasonably could have been expected to discover.’” The court then explained that because this standard raises a question of fact as to whether a diligent, skilled searcher would have found the references that the defendant desires to assert, a motion to strike was an inappropriate way of challenging the sufficiency of the invalidity defenses.

Practice Tip: A patent owner may be successful in moving a court to strike specific invalidity defenses that were raised in inter partes review (IPR) or PGR proceedings, precisely because the record is clear that such defenses were raised. But the same patent owner may find a court less receptive to striking other defenses because of a lack of record evidence showing that those other defenses reasonably could have been raised. When a patent owner faces a declaratory judgment or counterclaim for invalidity, and there are parallel proceedings at the PTAB, the patent owner should consider raising statutory estoppel as an affirmative defense. Under such circumstances, parties should assess, and be prepared to eventually produce, evidence showing whether a skilled searcher conducting a diligent search reasonably could have been expected to discover particular prior art.

GREE, Inc. v. Supercell Oy, No. 2:19-cv-00071 (E.D. Tex. Oct. 30, 2019) (Payne, U.S.M.J.)

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