35 U.S.C. § 315(e) prohibits a petitioner in an Inter Partes Review (“IPR”) that results in a final written decision from asserting, in litigation, invalidity “on any ground that the petitioner raised or reasonably could have raised during that inter partes review.” 35 U.S.C. § 315(e)(2).
In a previous post, we discussed how district courts enforce the estoppel of IPR in litigation. But this estoppel is no two-way street. On April 4, 2023, PTAB clarified “the AIA expressly imposes claim preclusion in one direction—from an IPR to other proceedings—but not in the other direction—from district-court litigation to Office proceedings.” Intel Corp. v. VLSI Tech. LLC, IPR2021-01064, Paper 132 at 6 (April 4, 2023).
In forming this opinion, PTAB relied heavily on Congressional intent. First, PTAB noted “the AIA inherently accepts the reality that parallel proceedings in a district court and the Office may address overlapping issues relating to asserted invalidity or unpatentability.” Intel, IPR2021-01064, Paper 132 at 6. Second, PTAB found “the AIA imposes a lower burden of proof for IPRs, in which unpatentability must be shown by a preponderance of the evidence rather than the clear and convincing evidence required for district-court invalidity.” Id. This “difference between IPRs and district-court invalidity,” PTAB concluded, “provides context to Congress adopting claim preclusion in only one direction.” Id. at 7.