Two’s Company, Three’s a (Discretionary) Crowd

by | May 13, 2026 | Joinder, PTAB News, PTAB Trial Basics

By Carl Kukkonen –

On January 9, 2026, the USPTO designated a Director decision in IPR2025-00258 as precedential, offering guidance on when the Patent Trial and Appeal Board (PTAB) will exercise its discretion to deny institution of inter partes review (IPR) proceedings in instances of joinder. The decision, involving a dispute between LED lighting manufacturers, reinforces the Office’s holistic approach to discretionary denials—and serves as a cautionary tale for petitioners considering their timing strategies.

The Parties and Background

The case pitted Elong International USA Inc. and Xiamen Longstar Lighting Co., Ltd (Petitioners) against Feit Electric Company, Inc. (Patent Owner) in a challenge to U.S. Patent No. 8,604,678 B2. The petitioners filed an IPR petition along with a motion for joinder to an already-instituted proceeding, IPR2024-01357, brought by Savant Technologies against the same patent.

Feit Electric filed a request for discretionary denial, asking the Director to decline institution based on the timing of parallel district court litigation.

Key Factors in the Decision

Acting Director Coke Morgan Stewart analyzed the petition both as a standalone filing and as if joinder were granted. In both scenarios, discretionary denial was appropriate:

Timing Mismatch: The projected final written decision in IPR2025-00258 would not issue until July 24, 2026, well after the district court’s scheduled trial date of January 20, 2026. Even under joinder, the joined proceeding’s final written decision was projected for March 5, 2026—still after trial.

Investment in District Court Proceedings: The parties had already invested meaningfully in the district court case, with a Markman hearing scheduled for May 15, 2025 and fact discovery nearing completion.

Unlikely Stay: There was insufficient evidence that the district court would stay its proceedings even if the PTAB instituted review.

Settlement Risk: The Director noted that if the original petitioner in IPR2024-01357 settled, the Office would be left maintaining a proceeding it would not have instituted for these petitioners alone.

The Joinder Angle

Petitioners attempted to sweeten the deal by offering stipulations—notably agreeing not to assert invalidity positions based on the same prior art in district court if joined. They also emphasized that their petition was identical to the one in IPR2024-01357, arguing that joinder wouldn’t burden the Board.

The Director was unpersuaded. According to the Director, these benefits did not outweigh the discretionary factors favoring denial. The decision makes clear that copying a successful petition and seeking to ride its coattails won’t automatically get you through the door—especially when your district court case is barreling toward trial.

Why This Decision Matters

The precedential designation signals that the USPTO wants practitioners to take these principles seriously:

Timing is Everything: Petitioners must carefully evaluate whether the PTAB can realistically issue a final written decision before trial. Filing late in the game—especially when trying to join an existing proceeding—is risky business.

Joinder Isn’t a Free Pass: Just because another petitioner has done the heavy lifting doesn’t mean you can coast through. The Director will scrutinize joinder requests through the same discretionary lens.

Holistic Analysis Prevails: The decision emphasizes that discretionary denial is based on a “holistic assessment of all of the evidence and arguments presented”—no single factor is dispositive.

The precedential designation of the IPR2025-00258 decision underscores the USPTO’s commitment to efficient resource allocation and reducing duplicative proceedings. For patent challengers, the message is clear: plan your IPR strategy early, keep an eye on district court schedules, and don’t assume that joinder will save the day.

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Carl Kukkonen

Partner at Jones Day
An acknowledged leader in the profession, Carl Kukkonen has nearly 20 years of experience in strategic intellectual property counseling. He advises clients on patent infringement and validity, preparation and prosecution of patent applications, and brand protection matters.