By Dhohyung Kim and Josh Nightingale –
On November 16, 2022, the United States Patent and Trademark Office (“PTO”) vacated a reexamination proceeding because the patent challenger relied on unpatentability grounds that reasonably could have been raised in an earlier inter partes review. Ex parte Reexamination of U.S. Patent No. 6,601,821, 90/014,950, Decision on Petition to Vacate Reexamination Order (USPTO, Nov. 16, 2022).
The case at issue involves a dispute between GITS Manufacturing Co. (“GITS”), a manufacturer of diesel engines, and G.W. Lisk Co. (“G.W. Lisk”), the owner of U.S. Patent No. 6,601,821 (“the ’821 patent”) directed to a valve assembly for an exhaust gas recirculation system. In 2016, G.W. Lisk filed suit against GITS in the U.S. District Court for the Southern District of Iowa, alleging that GITS’ diesel engines and related products infringe the ’821 patent. G.W. Lisk Company, Inc. v. Power Packer North America, Inc., No. 4:17-cv-00273 (S.D. Iowa).
GITS responded by challenging the claims of the ’821 patent in IPR proceedings. The Board issued final written decisions upholding some of the claims while finding others unpatentable.
Following the issuance of the final written decisions, GITS requested that the PTO conduct an ex parte reexamination of the claims that survived the IPRs. GITS’ request for ex parte reexamination relied on references that were not cited in the earlier IPRs. The PTO granted GITS’ request for reexamination, and G.W. Lisk shortly thereafter filed a petition to vacate the reexamination, arguing that GITS was barred from maintaining the reexamination proceeding under 35 U.S.C. § 315(e)(1).
Under 35 U.S.C. § 315(e)(1), once a final written decision on a claim of a patent is made by the PTAB, the IPR petitioner “may not request or maintain” a proceeding before the PTO “with respect to that claim on any ground that the petitioner raised or reasonably could have raised” during the earlier IPR. Here, G.W. Lisk filed a declaration from an “expert prior art searcher” opining that GITS reasonably could have raised the reexamination grounds in the prior IPR proceedings. The declarant testified that the reexamination references were “available in a number of commercial database” and included “a seminal textbook” in the field. The PTO agreed, finding the declaration persuasive.
Under 37 C.F.R. § 1.510(b)(6), a party requesting ex parte reexamination must certify that the statutory estoppel provisions of 35 U.S.C. § 315(e)(1) and 35 U.S.C. § 325(e)(1) do not prohibit the requester from filing the ex parte reexamination request. If any part of the certification is improper, then the entire certification is considered improper. Here, the PTO concluded that a skilled searcher reasonably could have uncovered the prior-art references cited by GITS in the reexamination request, and the certification submitted by GITS was therefore improper. As a result, the PTO concluded that GITS was estopped from maintaining the ex parte reexamination and terminated the proceeding.
Takeaway: A patent challenger filing an IPR petition should not “hold back” any references for a possible ex parte reexamination. After a final written decision in the IPR issues, the petitioner will be barred from maintaining a reexamination proceeding on any grounds that the petitioner raised or reasonably could have raised in the earlier IPR.
Latest posts by Josh Nightingale (see all)
- Federal Circuit Clarifies Important IPR Estoppel Issues - May 5, 2023
- PTAB Denies Authorization to Submit Exhibit For Not Following the Rules - March 3, 2023
- A Petitioner’s Guide: Navigating Uncertainty on PGR Eligibility - February 28, 2023