Judge Gilliam of the Northern District of California recently answered this question and provided helpful guidance on the interplay of IPRs, reexaminations and district court litigation. In IXI Mobile (R&D) Ltd., et al., v. Samsung Elec. Co. Ltd. and IXI Mobile (R&D) Ltd., et al. v. Apple Inc., Judge Gilliam denied plaintiffs’ (“IXI”) motion for leave to amend their infringement contentions and asserted claims because IXI was not diligent in identifying new contentions or new accused products. The Court also stated that, even if IXI was diligent, there would be undue prejudice to defendants if IXI were allowed to almost “triple” the number of claims that were initially asserted five years ago. While Judge Gilliam punted on the applicability of claim or issue preclusion on the new reexamination claims, Judge Gilliam noted that “there would appear to be obvious inefficiency in allowing [p]laintiffs to resurrect claims invalidated in IPR by turning to ex parte reexamination … an unresolved issue not squarely addressed by [the Federal Circuit in] Senju Pharm.”

The case began in 2014 in the Southern District of New York, where IXI filed suit for patent infringement against Apple and Samsung. The cases were later transferred to the Northern District of California in August 2015 and stayed in November 2015 pending the outcome of IPRs filed by Apple and Samsung against all asserted claims. In November 2016, the PTAB issued final written decisions invalidating all asserted claims except claim 10 of U.S. Patent No. 7,295,532 (“the ‘532 Patent”). Shortly thereafter, IXI appealed the PTAB decision with respect to U.S. Patent No. 7,039,033 (“the ‘033 Patent”) to the Federal Circuit.

Later, on March 2017, IXI also filed a petition for ex parte review of the ’033 Patent while its Federal Circuit appeal was pending, wherein it submitted amended claims and new claims. The PTAB issued an ex parte reexamination certificate on February 1, 2018 that amended one claim and added sixty-eight new claims. Apple also filed a petition for ex parte reexamination on April 3, 2018, while the Federal Circuit appeal remained pending, to challenge certain surviving claims of the ’532 Patent. In this reexam proceeding, IXI added thirty-five new claims. At the time of Judge Gilliam’s decision, this proceeding was still pending. On February 21, 2019, the court lifted the stay, despite the on-going reexamination of the ’532 patent, and IXI moved for leave to amend its infringement contentions and asserted claims.

The Court denied IXI’s motion. According to Judge Gilliam, IXI was not diligent, and even so, granting the motion would cause undue prejudice to Apple and Samsung. The Court noted that IXI cannot amend contentions and asserted claims just because new claims were added during the reexamination. Judge Gilliam explained that IXI should have provided proposed changes to the contentions or identified potentially new infringing products on the market. The Court stated that IXI did not demonstrate that they even investigated if there were other potential infringing products. While the Court did not specifically address the preclusion issue, it noted that res judicata, as discussed in Senju Pharm. Co. v. Apotex, 746 F.3d 1344, 1353 (Fed. Cir. 2014), may not apply because the asserted claims were first invalidated in an IPR proceeding, not district court.

This case provides instructive guidance to patent owners who may seek to assert newly-added claims from a reexamination in on-going litigation proceedings. With respect to the issue of res judicata, it seems to be an open question of whether newly-added claims can be asserted against defendants after an IPR has invalidated some or all of the original asserted claims. As a result, patent owners may be able to proceed with newly-added claims but should determine if there are any additional infringing products that may have entered the market in light of the new claims and also provide the court with proposed changes to the contentions.