In a recent order, the Eastern District of Texas declined to preclude a defendant from raising prior art system references despite patentee’s argument that similar printed publications could have been raised in earlier inter partes review (IPR) petitions.

After plaintiff United Services Automobile Association (USAA) sued defendant PNC Bank N.A. for patent infringement, PNC filed IPR petitions against each of the six patents-in-suit, of which three were instituted by the Patent Trial and Appeal Board. In each of these petitions, PNC stipulated that “if this IPR is instituted, it will not advance the grounds that are raised or reasonably could have been raised in this IPR in the co-pending district court proceeding.”

In the parallel district court proceeding, PNC asserted prior art system references, which were related to printed publications describing the system. In response, USAA filed a motion in limine to preclude PNC from asserting these system references on the basis that the related printed publications could have been raised in the IPR proceedings.

The court pointed out that district courts are split on the issue of whether a party is estopped from asserting a system reference when there is a related printed publication. The court, however, declined to preclude PNC from raising invalidity defenses based on these system references because it was “not clear on th[e] record that the related publications fully describe[d] all relevant features of the asserted systems.”

Practice Tip: Though prior art systems cannot be raised during IPR proceedings, some district courts have struggled with the issue of whether a party should be precluded from asserting a system reference when there is a related printed publication that could have been raised in IPR proceedings. Parties to litigation should recognize that estoppel may not preclude the assertion of system references, especially if the accused infringer can show that the system has features not disclosed in related prior art publications.

United Services Automobile Association v. PNC Bank, NA, No. 2-20-cv-00319 (E.D. Tex. Apr. 28, 2022) (Roy S. Payne).