In a recent opinion in ESIP Series 2, LLC v. Puzhen Life USA, LLC, the US Court of Appeals for the Federal Circuit determined that 35 USC 314(d), which bars appellate review of US Patent and Trademark Office decisions to institute an inter partes review, includes determinations relating to the identification of real parties in interest. This continues a series of judicial decisions that have defined which aspects of Patent Trial and Appeal Board decisions relating to inter partes review may be considered on appeal.
The statutes governing the institution of inter partes review (IPR), post-grant review (PGR), and covered business method (CBM) proceedings before the Patent Trial and Appeal Board (PTAB) of the US Patent and Trademark Office (PTO) require that a petition for IPR, PGR, or CBM “may be considered only if . . . the petition identifies all real parties in interest.” Failure to identify all real parties in interest results in the denial of a petition or the dismissal of the proceeding.
In ESIP Series, the Federal Circuit referenced Cuozzo Speed Techs., LLC v. Lee, in which the US Supreme Court held that the Federal Circuit is barred from “reviewing [PTAB] decisions concerning the ‘particularity’ requirement under § 312(a)(3)” in instituting an IPR proceeding, and the Supreme Court’s recent decision in Thryv, Inc. v. Click-to-Call Techs., LP, which said that PTAB decisions relating to the time bar set forth in 35 USC § 315 are also not reviewable on appeal.
Based on these two decisions and because the patent owner’s “contention that the Board failed to comply § 312(a)(2) is ‘a contention that the agency should have refused to institute an inter partes review,’” the Federal Circuit found “no principled reason why preclusion of judicial review under § 314(d) would not extend to a [PTAB] decision concerning the ‘real parties in interest’ requirement of § 312(a)(2).”
Notably, the PTAB does not always decide the issue of whether a petition adequately identifies all real parties in interest at the institution stage of a proceeding, as there have been instances where the PTAB instituted a petition but allowed additional discovery during the proceeding relating to real-party-in-interest issues. These decisions may lead to a post-institution determination related to real party in interest, as was the case in this IPR between Puzhen Life and ESIP Series 2.
While the Federal Circuit’s articulation of the rule in ESIP Series applies to decisions at the institution stage, it appears that the PTAB’s findings related to real parties in interest in final written decisions will also be barred from appellate review.
 35 USC §§ 312(a)(2) & 322(a)(2).
 ESIP Series 2, LLC v. Puzhen Life USA, LLC, No. 2019-1659 (Fed. Cir. 2020).
 136 S. Ct. 2131 (2016).
 The PTO’s proposed rule to “amend the rules to eliminate the presumption in favor of the petitioner for a genuine issue of material fact created by testimonial evidence submitted with a patent owner's preliminary response when deciding whether to institute an IPR, PGR, or CBM review” may impact whether the PTAB will be prepared to institute proceedings if presented with questionable real-party-in-interest information. See PTAB Rules of Practice for Instituting on All Challenged Patent Claims and All Grounds and Eliminating the Presumption at Institution Favoring Petitioner as to Testimonial Evidence, 85 Fed. Reg. 31728 (proposed May 27, 2020).
 Puzhen Life USA, LLC v. ESIP Series 2, LLC, IPR2017-02197, Paper 24 (determining that petitioner’s identification of real parties in interest was not incomplete); see also, e.g., Atlanta Gas Light Co. v. Bennett Regulator Guards, IPR2013-00453, Paper 88 (vacating institution decision and terminating IPR proceeding after determining that all real parties in interest were not identified).