In an inter partes review proceeding challenging the patentability of claims 1 to 11 of the patent, the PTAB construed several claim terms and determined that no claims were unpatentable for anticipation, but ruled those claims unpatentable as obvious. The patent owner appealed the obviousness ruling to the Federal Circuit. On appeal, the IPR petitioner argued—in the alternative—that if the obviousness ruling were reversed, the Federal Circuit should construe the claims differently and find them unpatentable for anticipation. The Federal Circuit affirmed the PTAB’s obviousness determination, and expressly declined to reach the petitioner’s alternative argument regarding claim construction.
During the pendency of the IPR proceeding, the patent owner asserted the patent in district court litigation against a party unrelated to the IPR petitioner. After the PTAB’s unpatentability rulings on claims 1 to 11, claim 12 was left as the only remaining asserted claim. Claim 12 included limitations that were also present in claims 1 to 11 and at issue in the IPR petitioner’s claim construction dispute. The district court ordered briefing on how the outcome of the IPR proceeding affected the litigation. In response, the accused infringer sought leave to file a motion for summary judgment on the invalidity of claim 12. The accused infringer argued that by affirming the PTAB’s decision, the Federal Circuit necessarily relied on the PTAB’s constructions, making them binding on the district court and precluding patent owner from arguing otherwise.
The district court denied the request. The court explained that while a Federal Circuit decision on claim construction is a binding issue of law under stare decisis, the Federal Circuit did not actually address or decide any of the claim construction issues. Rather, the Federal Circuit had expressly declined to address any claim construction dispute raised by the IPR petitioner, and had only ruled on the use of general knowledge and the sufficiency of the factual findings underpinning the PTAB’s decision. The district court also ruled that the doctrine of collateral estoppel did not apply because the district court and PTAB had applied different standards of claim construction.
Practice Tip: A party in district court litigation seeking to benefit from stare decisis or collateral estoppel arising from PTAB proceedings and appeals therefrom should be prepared to show that the specific issue was actually litigated in the related proceeding and, if necessary, specifically affirmed on appeal.
In re Koninklijke Philips Patent Litig., 18-cv-01885-HSG (N.D. Cal. May 26, 2020) (Gilliam, Jr., J.)