Divergent Claim Construction Results in Discretionary Denial

by | Oct 29, 2025 | Claim Construction, PTAB News, PTAB Trial Basics, Trial Institution

By Evan Tassis and Matt Johnson –

In a recent decision, Acting Director Coke Morgan Stewart granted Patent Owner’s request for discretionary denial in Sun Pharmaceuticals Industries Inc. v. Nivagen Pharmaceuticals, Inc., IPR2025-00893.  While some factors weighed against denial, the Acting Director emphasized Patent Owner’s different claim construction positions in the current proceeding and the parallel district court case as favoring denial.

On April 22, 2025, Sun Pharmaceuticals Industries Inc. (“Petitioner”) filed a petition requesting an inter partes review of U.S. Patent No. 11,878,076 (“the ’076 Patent”) directed to compositions of phenobarbital.  On July 18, 2025, Nivagen Pharmaceuticals, Inc. (“Patent Owner”) filed a request for discretionary denial arguing that the IPR should be discretionarily denied partly because the projected final written decision would issue before the parallel district court trial.

In an order granting Patent Owner’s request for discretionary denial, the Acting Director first considered factors weighing against discretionary denial.  The timing of the proceedings weighed against discretionary denial because the IPR’s projected final written decision was expected well before any district court trial, which had not yet been scheduled and was unlikely to occur before 2029.  Additionally, the ’076 Patent was recently issued in 2024, so there were no strong settled expectations in favor of the Patent Owner.

However, the Acting Director found that other factors favored discretionary denial.  Most notably, Petitioner took inconsistent positions regarding claim construction in the IPR and in the parallel district court litigation.  Specifically, Petitioner argued for a broad, plain and ordinary meaning of the term “composition” in the IPR, while advocating for a narrower interpretation in district court.  The Acting Director noted that while parties are not absolutely barred from taking different positions in different forums, they must provide a sufficient explanation for any such differences.  In this case, Petitioner did not adequately justify its inconsistent claim construction arguments.  After weighing all considerations, the Acting Director granted Patent Owner’s request for discretionary denial and declined to institute trial.

Takeaway:  Parties should be mindful that the PTAB may scrutinize the consistency of claim construction positions taken in IPR proceedings and parallel district court litigation.  Parties should coordinate litigation and IPR strategies early, ensure alignment in claim construction arguments, and document any necessary changes in position with supporting rationale.

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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.