Joining an IPR Triggers IPR Estoppel Only for Instituted Grounds

| Alexander D. ZengJustin J. Gillett


Before Prost, Newman, and Bryson. Appeal from the United States District Court for the Eastern District of Texas.

Summary: A party joined to an IPR under 35 U.S.C. § 315(c) is not statutorily estopped from raising in district court any invalidity grounds other than those that were instituted in the IPR, because the joining party cannot raise additional grounds during the IPR.

Network-1 sued HP, Avaya, and other defendants in federal district court alleging infringement of one patent. Avaya petitioned for inter partes review (“IPR”) of the asserted patent, and the Patent Trial and Appeal Board (the “Board”) instituted IPR based on two grounds. After institution, HP filed its own petition for IPR of the asserted patent and also moved to join Avaya’s IPR. The Board found that HP’s petition was time barred under 35 U.S.C. § 315(b) because it had been filed more than one year after Network-1 served HP with its district-court complaint, but the Board granted HP’s motion to join Avaya’s IPR. Thereafter, the Board issued a final written decision in Avaya’s IPR upholding patentability of the asserted patent over the instituted grounds.

The district court case later proceeded to trial, where HP argued that Network-1’s asserted patent was rendered obvious both by public use of an allegedly prior-art system and by patents and printed publications that had not been included in the instituted IPR. Using a general verdict form, the jury found the asserted patent was invalid. But following the verdict, the district court granted a motion by Network-1 for judgment as a matter of law (“JMOL”) on invalidity. The district court reasoned that the proffered public use was not prior art and that HP was estopped under 35 U.S.C. § 315(e) from raising its obviousness challenges based on patents and printed publications because HP had joined Avaya’s IPR. Network-1 appealed regarding other issues and HP cross-appealed the portion of the district court’s invalidity decision regarding estoppel.

The Federal Circuit vacated the district court’s JMOL regarding invalidity and remanded for further proceedings. It stated that, although HP had been time barred under § 315(b) from bringing its own IPR petition, HP was permitted to join Avaya’s IPR as a party under § 315(c). The Federal Circuit noted that § 315(c) does not permit the joining party to raise new grounds of invalidity that had not been instituted. The court therefore reasoned that HP, as the joining party, could not have raised any additional invalidity challenges in Avaya’s IPR. The estoppel statute, § 315(e), applies only to grounds that a party “raised or reasonably could have raised” during the subject IPR. The Federal Circuit concluded that because HP could not have raised in Avaya’s IPR its obviousness challenges based on patents and printed publications that had not been instituted, HP was not estopped under § 315(e) from raising those obviousness challenges in district court.

Editor: Paul Stewart