As previously discussed in our post covering the state of IPR estoppel, initial district court decisions have varied regarding the scope of IPR estoppel applied to ground for invalidity not raised in a petition, but that could have been raised. Two recent decisions may show a trend toward uniformity.

In Cobalt Boats, LLC v. Sea Ray Boars, Inc., Judge Morgan of the Eastern District of Virginia ruled on motions in limine, including a motion regarding the scope of IPR estoppel. Case no. 2:15cv00021 (E.D. Va. June 5, 2017). The court noted that other district courts have split on the application of the Federal Circuit’s Shaw opinion with regard to whether estoppel is limited only to grounds raised in an IPR petition and for which institution was granted. Shaw Indus. Grp., Inc. v. Automated Creel Sys., Inc., 817 F.3d 1293, 1297-1300 (Fed. Cir. 2016). The court here held that estoppel applies to grounds that the petitioner could have raised in the IPR petition, reasoning that the broader reading of Shaw adopted by some courts that limits estoppel only to those grounds for which institution was granted renders the IPR estoppel provisions essentially meaningless. The defendants sought to rely upon several prior art products to invalidate the patent-in-suit. First, the defendants argued that, because the products were not themselves printed publications or patents, they could not have been raised in the IPR. The court deferred a decision on that argument. Second, the defendants argued that the prior art references were not reasonably available through searching. Plaintiff responded that an internet (Google) search restricted by the patent’s filing date and limited to key terms from the patent reveals three of the prior art references within the top ten search results. The court was persuaded that these were all reasonably available at the time the defendants filed the IPR petition. Finally, the defendants argued that the product manuals for those products were not reasonably available through searching. The court did not believe that the defendants were unaware of a larger competitor’s product lines and found that the product manuals for two products were reasonably available through searching. Accordingly, the court estopped the defendants from arguing invalidity grounds based upon those prior art references that the court determined were reasonably available through searching.

Similarly, in Oil-Dri Corp. of America v. Nestle Purina Petcare Co., Judge St. Eve of the Northern District of Illinois granted in part a motion to exclude certain prior art. Case No. 15cv1067 (N.D. Ill. Aug. 2, 2017). The plaintiff (patentee) argued that the defendant was estopped from arguing invalidity based on (1) grounds that were raised in the IPR petition but not instituted, and (2) grounds not raised in the IPR petition that could have reasonably been raised. The court rejected the plaintiff’s first argument and applied Shaw’s holding that estoppel does not apply to invalidity grounds that were raised but not instituted. The court denied the motion with respect to references identified in the petition supporting grounds for which IPR was not instituted. With regard to the grounds not raised and references not identified in the petition, the court agreed with the plaintiff that defendant was estopped from arguing invalidity as to references a skilled searcher conducting a diligent search reasonably could have been expected to discover. Both parties submitted declarations from registered patent agents discussing what diligent searches reasonably could have discovered. With respect to four pieces of prior art, the declaration submitted by the defendant admitted that a “reasonably skilled patent searcher may have identified” those references. The court granted the motion estopping the defendant from arguing invalidity grounds based upon those references. For the remaining references as to which a dispute remains, the court denied the motion without prejudice but stated that the references would be addressed at the next status hearing.

These cases add to a body of law finding (1) that estoppel does not apply to invalidity grounds raised in an IPR petition but not instituted and (2) that estoppel does apply to prior art references that were reasonably available through searching but that were not raised in the IPR petition.