Post-filing Activity May Create Privity Leading To Section 315(b) Dismissal

by | Sep 16, 2025 | PTAB News, PTAB Trial Basics, Real Party in Interest, Trial Institution

By Sue Gerber and Matt Johnson –

Under Section 315(b), an IPR may be dismissed as time barred “if the petition requesting the proceeding is filed more than 1 year after the date on which the petitioner, real party in interest, or privy of the petitioner is served with a complaint alleging infringement of the patent.”  35 U.S.C. § 315(b) (emphasis added).  The petitioner bears the burden of establishing that no real parties in interest or privies were served with a complaint more than year prior to filing an IPR.  RØDE Microphones, LLC v. Zaxcom, Inc., IPR2025-00231, Paper 33 (PTAB Aug. 21, 2025). “The determination of whether a nonparty is a real party in interest or privy is made as of the date of institution of a proceeding, even if the relationship between the nonparty and petitioner arises after filing but before institution.”  Id.

What constitutes privity is a fact-specific analysis that seeks to “determine whether the petitioner and the prior litigant’s relationship—as it relates to the lawsuit—is sufficiently close that it can be fairly said that the petitioner had a full and fair opportunity to litigate the validity of the patent in that lawsuit.”  Id. at 3-4.  The PTAB considers the following non-exhaustive list of factors establishing privity to examine the legal relationship between parties:  “(1) an agreement between the parties to be bound; (2) pre-existing substantive legal relationships between the parties; (3) adequate representation by the named party; (4) the nonparty’s control of the prior litigation; (5) where the non-party acts as a proxy for the named party to relitigate the same issues; and (6) where special statutory schemes foreclose successive litigation by the non-party (e.g., bankruptcy and probate).”  Id. at 5 (citing Taylor v. Sturgell, 553 U.S. 880,893-95 (2008)).

This question of privity arose under an interesting set of facts in RØDE Microphones.  There, the patent owner had previously sued another party, Lectrosonics, for infringement of the challenged patent in 2017.  About six months before RØDE’s filing an IPR in 2025, RØDE and Lectrosonics developed a business relationship that included executing an NDA and a letter of intent paving the way for RØDE to acquire Lectrosonics.  After the IPR was filed, but before institution, RØDE acquired Lectrosonics as a wholly-owned subsidiary.  Applying at least factors 2 and 5 from Taylor, the PTAB found that RØDE and Lectrosonics were in privity based upon their pre-filing communications regarding the challenged patent and post-filing company acquisition.  Given this privity relationship between RØDE and Lectrosonics, the PTAB determined that the IPR was time barred, vacated the institution decision, and terminated the proceedings.

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Matthew Johnson

Partner at Jones Day
Matt Johnson is one of the Firm's primary contacts on practice before the PTAB. Currently co-chairing the Firm's PTAB subpractice and involved in proceedings at the Board since the first day of their availability in September 2012, Matt regularly represents clients as both petitioners and patent owners at the Board. He further works as an advocate for clients in appeals from Board proceedings at the Federal Circuit.