PTAB Tracker

June 25, 2021

Westlake Services, LLC v. Credit Acceptance Corp., Case CBM2014-00176, Paper 28

35 U.S.C. § 325(e)(1) estops a petitioner from requesting or maintaining “a proceeding before the Office with respect to that claim on any ground that the petitioner raised or reasonably could have raised” in a prior IPR or other post-grant proceeding against that patent that has resulted in a Final Written Decision.  In this case, Westlake had filed a prior CBM petition against the same patent which had been instituted with respect to some, but not all, of the challenged claims.  After the Supreme Court’s decision in Alice Corp. v. CLS Bank, 134 S. Ct 2347 (2014), Westlake filed the follow-up CBM petition at issue in this proceeding challenging the claims for which institution had previously been denied as unpatentable under § 101 based on the Alice precedent.  After a Final Written Decision was issued in the earlier proceeding, Patent Owner Credit Acceptance requested permission to file a motion to terminate this proceeding under § 325(e)(1), arguing that Westlake was estopped from continuing to pursue unpatentability before the PTAB of any of the claims addressed in the earlier filed petition.

In this decision, the Board found that the Westlake was not estopped from maintaining post-grant proceedings against the claims for which institution had previously been denied, stating that those claims “are not claims in a patent that have resulted in a Final Written Decision under Section 328(a), and thus, under Section 325(e)(1), estoppel does not apply to those claims.” (page 5.)  The Board went on to find that concerns regarding previously raised arguments for patentability are better addressed by the discretion “to deny petitions that submit the same or substantially the same prior art or arguments previously presented to the Office” provided by § 325(d).  In this particular case, the Patent Owner had already raised such arguments regarding § 325(d) discretion in its Preliminary Response—arguments ultimately rejected by the Board in the Institution Decision.


The Board further found that the change in precedent based on recent Supreme Court decisions between the filing of the two petitions overcame any concerns regarding duplicative arguments based on § 101 eligibility between the two petitions.  Specifically, the Board found that the fact pattern here presented “unique circumstances” with respect to the application of § 325(d) discretion.


  1. Estoppel under 35 U.S.C. § 325(e)(1) is applied on a claim by claim basis.  Therefore, Patent Owner’s should only move to terminate an IPR or other post-grant proceeding based on § 325(e)(1) estoppel with respect to claims actually addressed in a prior Final Written Decision.
  2. Although this case remains precedential, the shift to “all or nothing” institution of IPR and PGR petitions after the Supreme Court’s decision in SAS Inst., Inc. v. Iancu, 138 S. Ct. 1348 (2018) minimizes the effects of this decision going forward.


Rick Bisenius | Principal | Minneapolis

Rick Bisenius is a principal in the patent group in the Twin Cities office of Fish & Richardson P.C. His practice emphasizes patent post-grant proceedings (IPR and CBM), patent reexamination proceedings, U.S. and foreign patent portfolio strategy and management, and due diligence investigations.... Read More