On March 9, 2021, the Federal Circuit affirmed several inter partes review (IPR) decisions of the Patent Trial and Appeal Board (PTAB) related to the estoppel provision 35 U.S.C. § 315(e)(1). Uniloc 2017 LLC v. Facebook Inc. et al., Nos. 19-1688 and 19-1689 (Fed. Cir. March 9, 2021). The estoppel provision of 35 U.S.C. § 315(e)(1) precludes an inter partes review petitioner who has received a final written decision from raising a claim “on any ground that the petitioner raised or reasonably could have raised during that inter partes review” at the USPTO. The court first considered whether the estoppel provision applies to a party to an IPR when that party is procedurally joined with another party in an IPR proceeding. Second, the court considered whether a petitioner is precluded from an IPR challenge of a dependent claim based upon estoppel of a challenge to the independent claim upon which it relies in a separate IPR, to which it is joined. The court answered no to both considerations but cited the fact pattern and timing of the joinder and written decisions; in other words, “it depends.”

IPR Filings and PTAB Proceedings

Uniloc owns the ’433 patent, which relates to a Voice over Internet Protocol (VoIP) messaging system for sending voice messages to a recipient. On May 11, 2017, Facebook filed two IPR petitions against the Uniloc ’433 patent. The first petition (’1427 IPR) challenged claims 1-8 as obvious and the second petition (’1428 IPR) challenged a different set of claims – claims 9-11, 12, 14, 15-17, 25 and 26 – as obvious. At that time, Apple had a pending IPR petition against the ’433 patent. Facebook filed a third IPR petition that was substantively identical to the Apple’s IPR petition on June 16, 2017 and filed a motion to join Apple’s IPR petition, which the PTAB granted.

Next, LG filed IPR petitions that were substantively identical to Facebook’s ’1427 and ’1428 petitions along with motions to join the ’1427 and ’1428 IPRs. The Board procedurally required LG and Facebook to consolidate their arguments and evidence in combined filings. On December 4, 2017, the PTAB instituted review of the ’1427 and ’1428 IPR petitions. On March 6, 2018, the PTAB instituted LG’s IPRs and granted LG’s motion to join Facebook’s two IPRs. Then, on May 23, 3018, in a final written decision, the PTAB upheld the patentability of all claims in the Apple IPR. On May 29, 2018, the PTAB decided that Facebook was estopped under 35 U.S.C. § 315(e)(1) from challenging claims 1-6 and 8 in the ’1427 petition, which were the same claims challenged in the Apple IPR. The PTAB said, however, that Facebook was not estopped from its challenge to claim 7 because this claim had not been part of the Apple IPR and that LG was not estopped from its IPR challenges to the ’433 patent.

On November 20, 2018, the PTAB issued a final written decision in Facebook’s ’1427 and ’1428 IPRs, finding all the challenged claims unpatentable. Uniloc appealed both decisions to the Federal Circuit. Uniloc’s estoppel-related arguments were, first, that LG should be estopped from challenging claims 1-6 and 8 of the ’433 patent because LG is a real party in interest or privy of Facebook and, second, that Facebook should be estopped from challenging claim 7.

Federal Circuit’s Holdings

As a threshold issue, the Federal Circuit considered whether 35 U.S.C. § 314(d) precluded its review of the PTAB’s decision regarding estoppel and concluded that it did not. Under § 314(d), “[t]he determination by the Director [of the Patent Office] whether to institute an inter partes review under this section shall be final and nonappeable.” The court reasoned that the alleged estoppel-triggering event (the Apple IPR final written decision) occurred after institution of the Facebook IPRs. Therefore, the Federal Circuit’s review of this decision was not a review of the institution of the Facebook ’1427 IPR.

Next, the Federal Circuit considered whether LG should be estopped from its IPR challenge under estoppel provision 35 U.S.C. § 315(e)(1). This analysis involved determination of whether LG was a real party in interest (RPI) or privy of Facebook, for which there is no bright line rule. Instead, the Court looked to factors such as LG’s level of control over Facebook’s decision to file the ’1427 IPR, LG’s involvement in Facebook’s IPR arguments, whether Facebook recruited LG to join its IPR, and whether LG and Facebook had a preexisting relationship or received funding from each other. The Court found no evidence in the record to support any of these factors, finding instead that LG acted independently of Facebook in filing its IPRs on the ’433 patent. The Federal Circuit stated that LG was not estopped from its challenges of claims 1-6 and 8 in the ’1427 IPR merely because it was procedurally joined with Facebook in the IPR.

Second, the Federal Circuit considered Uniloc’s argument that Facebook was estopped from challenging claim 7 of the ’433 patent. The PTAB had previously found that Facebook was estopped from challenging claims 1-6 and 8 because those claims were part of the Apple IPR that Facebook had joined. Uniloc argued that claim 7 was dependent from claim 1 and therefore allowing a challenging on claim 7 was equivalent to a challenge on claim 1. The court reviewed the plain language of 35 U.S.C. § 315(e)(1) and found nothing that would preclude Facebook’s challenge of claim 7. In addition, the Court noted that Facebook, as a joined party, could not have raised any arguments related to claim 7 in the Apple IPR since it did not include that claim. Therefore, the Federal Circuit agreed with the PTAB’s decision that Facebook was not estopped from challenging claim 7.

What This Means for You

This case illustrates several aspects of the metes and bounds of estoppel provision 35 U.S.C. § 315(e)(1). First, when joining an IPR, companies should carefully consider their relationship to the other companies joined in the IPR petition. If the PTAB determines that a joint petitioners’ claim challenges are subject to estoppel, courts may consider various factors in deciding whether the estoppel affects other joint petitioners’ claim challenges. Specifically, courts may look at whether one joined company is a real party in interest or privy to the other joined company. Second, the estoppel provision operates on a claim-by-claim basis, regardless of whether a challenged claim is dependent on a claim that a joined petitioner was estopped from challenging.