UPDATE: On Feb. 22, 2022, the Federal Circuit issued an errata to the original decision clarifying that the IPR estoppel only applies to challenged claims. The corrected language reads, in relevant part, that “estoppel applies […] to all grounds not stated in the petition but which reasonably could have been asserted against the claims included in the petition.” This errata alleviated concerns that the ruling might be interpreted to extend IPR estoppel to unchallenged claims.
In its recent decision in Caltech v. Broadcom Limited, et al, the Federal Circuit expanded the scope of Inter Partes Review (“IPR”) estoppel “to all claims and grounds… which reasonably could have been included in [an IPR] petition.” (emphasis added). In its decision, the court overruled Shaw Industries Group, Inc. v. Automated Creel Systems, Inc., which previously explained the meaning of “during an IPR” when analyzing the scope of IPR estoppel. According to Shaw, because an IPR “does not begin until it is instituted,” the statutory scope did not cover grounds that are only raised or reasonably could have been raised in a petition. Caltech clarifies that estoppel applies not just to claims and grounds asserted in the petition and instituted for consideration by the Board, but to all claims and grounds not in the IPR but which reasonably could have been included in the petition.
In reaching its decision, the Federal Circuit relied on the Supreme Court decision in SAS Institute, Inc. v. Iancu, which ruled that it is the petition, not the institution decision, that defines the scope of an IPR. The Federal Circuit decision will be viewed favorable for patent owners as they may face fewer challenges in a district court case subsequent to an IPR. For petitioners, they will need to carefully decide when to file IPRs and fully consider all of the invalidity defenses that they will be estopped from bringing up later in the district courts.
 No. 2020-2222, ___ F.2d ___ (Fed. Cir. 2022).
 817 F.3d 1293 (Fed. Cir. 2016).
 138 S. Ct. 1348 (2018).