By Ryan Davis (February 11, 2022, 9:51 PM EST) — A recent Federal Circuit ruling will restrict companies that have challenged patents in inter partes reviews from making invalidity arguments in later infringement litigation that some courts had allowed, turning IPRs into the primary battleground for validity disputes, attorneys say.

The Feb. 4 decision made headlines for vacating a $1.1 billion damages award that the California Institute of Technology won against Apple and Broadcom, but another aspect of the ruling will be a boon for patentees and has implications for nearly every patent dispute.

The decision hinges on the America Invents Act’s estoppel provision, which states that after a final IPR…