IPWatchdog

Federal Circuit Reverses IPR Estoppel Ruling Against Valve, Finds Insufficient Search Evidence and Hindsight Bias

The U.S. Court of Appeals for the Federal Circuit (CAFC) issued a precedential decision today in Ironburg Inventions Ltd. v. Valve Corporation, reversing a district court ruling that had estopped ...
JD Supra

Searchable Is Not Enough: The Federal Circuit Raises the Bar for Estopping ‘New’ Prior Art

After an accused infringer files an IPR, it may still try to assert additional prior art later in district court. Patentees often respond by ...
JD Supra

The Party Seeking IPR Estoppel Bears ‎the Burden to Prove Non-Petitioned Invalidity Grounds ‎‎Reasonably Could Have Been Raised

In the April 3, 2023 decision in Ironburg Inventions Ltd. v. Valve Corporation, 21-2296, Doc. 66, the Federal Circuit provides crucial guidance regarding inter partes review (IPR) estoppel under 35 ...
Reuters

IPR tricks of the trade: Federal Circuit clarifies standard for IPR estoppel

April 17, 2023 - Patent Trial and Appeal Board (PTAB) post-grant validity challenges — for example, inter partes review — are frequent components of a patent litigation strategy for defendants.
Reuters

Federal Circuit limits IPR estoppel for ongoing reexaminations

January 15, 2026 - Patent Trial and Appeal Board (PTAB) post-grant validity challenges, for example, inter partes review (IPR), are frequent components of a patent litigation strategy for defendants.