Originally published in IPWatchdog on March 19, 2025.

The U.S. Court of Appeals for the Federal Circuit’s precedential decision in Kroy IP Holdings LLC v. Groupon Inc. (Kroy IP) has significant strategic implications for patent litigation and inter partes review (IPR) proceedings. The holding, facts, and procedural aspects of Kroy IP are well covered here. This article focuses on how the decision affects patent litigation and IPR strategies for both patent owners and IPR petitioners.

Kroy IP significantly narrowed the scope of IPR estoppel. In particular, a final written IPR decision that certain claims are unpatentable cannot collaterally estop a patent owner from asserting other, unadjudicated patent claims in district court litigation. This is true even if the unadjudicated claims are “immaterially different.” This decision has several important implications.

To read the full article, visit here.