Michael (Mike) R. Weiner, Partner

PTABWatch Blog

PTABWatch, provided by Marshall, Gerstein & Borun LLP, analyzes and reports recent developments concerning Post-Grant Proceedings at the Patent Trial and Appeal Board (PTAB) of the U.S. Patent and Trademark Office (USPTO), including Inter Partes Review (IPR), Post Grant Review (PGR), and Covered Business Method (CBM) proceedings.

Recent Blog Posts

• Federal Circuit Ignores Precedent, Applies Collateral Estoppel In mCom IP, LLC v. City National Bank of Florida (Fed. Cir. May 15, 2026), the Federal Circuit affirmed a district court decision dismissing mCom’s patent infringement complaint under Rule 12(b)(6) for failure to state a claim, on the basis that the asserted claims of mCom’s U.S. Patent No. 8,862,508 (relating to electronic banking systems) were not materially different from claims of the same patent that had previously been canceled by the PTAB in an IPR: [T]he court separately reviewed each... More
• Federal Circuit Decides First Derivation Appeal Seven years after the PTAB instituted the first AIA derivation proceeding, the Federal Circuit finally issued its first opinion in an appeal of a derivation decision, Global Health Solutions, LLC v. Selner, No. 23-2009 (Fed. Cir. 2025), affirming the Board’s decision that the petitioner did not carry its burden to show respondent (Selner) derived the invention from the petitioner’s inventor (Burnam).Both parties filed applications claiming formulations of a particular biocide, PHMB (polyhexamethylene biguanide) suspended in petroleum jelly, each naming a... More
• Court Limits Collateral Estoppel Based on PTAB Decisions In ParkerVision, Inc. v. Qualcomm Inc., No. 2022-1755, -2221 (Fed. Cir. Sept. 6, 2024) (“ParkerVision III”), the Federal Circuit held that, due to the difference in burdens of proof in PTAB IPR proceedings and in district court cases, collateral estoppel cannot be applied in a district court case based on findings made by the PTAB in connection with a decision that related, but not identical claims are unpatentable:Although we have not previously addressed the question of whether a finding underlying... More
• Assignor Estoppel Does Not Prevent Reliance on PTAB Decision Canceling Claims In Hologic, Inc. v. Minerva Surgical, Inc., Case 19-2054 (Fed. Cir. Apr. 22, 2020), the Federal Circuit held that an assignor of a patent may rely on a PTAB unpatentability decision as a defense in infringement litigation, although the equitable doctrine of “assignor estoppel” prevents the assignor from directly challenging validity in the litigation. In Additional Views, Judge Stoll suggests that the en banc court reconsider the issue of assignor estoppel, because the court’s precedent permits an assignor of a... More
• Time Bar Challenge Must Be Raised before the Board, Not Saved for Appeal Since the Federal Circuit’s 2018 en banc decision in Wi-Fi One, LLC v. Broadcom Corporation, (discussed here) the court has reviewed a number of PTAB decisions on whether an IPR petition was filed more than one year after the petitioner was served with a complaint asserting the challenged patent, and thus time-barred under 35 U.S.C. § 315(b) (see here, here, here). But a patent owner’s time-bar challenge must be timely raised before the PTAB, and may be waived if raised... More
• Don’t Save New Fish to Fry in Reply In Henny Penny Corp. v. Frymaster LLC (Fed. Cir. 2019), the Federal Circuit again upheld the PTAB’s application of its rule prohibiting petitioners from raising new arguments in a reply brief, and upheld the challenged claims as not unpatentable for obviousness, relying in part on secondary considerations evidence.Henny Penny filed an IPR petition challenging a Frymaster patent covering commercial deep fryers. The challenged claims recite a system for monitoring frying oil impurities know as total polar materials (“TPMs”).The system includes... More
• Corroboration Required to Prove Earlier Invention Date As we have discussed (here and here), owners of pre-AIA patents may be able to “swear behind” alleged prior art references by providing evidence of an earlier invention date, but the inventors’ testimony concerning conception of the invention must be corroborated by independent evidence. In Kolcraft Enterprises, Inc. v. Graco Children’s Products, Inc., No. 2018-1259 (Fed. Cir. Jul. 2, 2019), the patent owner was unable to swear behind alleged prior art because it did not provide sufficient corroborating evidence.The patent... More
• Estoppel May Not Apply When Petitioner Lacks Standing to Appeal IPR Decision In AVX Corp. v. Presidio Components, Inc., No. 2018-1106 (Fed. Cir. May. 13, 2019), the Federal Circuit determined that a manufacturer did not have standing to appeal an adverse decision in an IPR challenging a competitor’s patent, because the petitioner did not have a present or nonspeculative interest in engaging in conduct arguably covered by the patent. The decision leaves open the question of whether a petitioner that lacks standing to appeal would be bound by petitioner estoppel under 35... More
• Petitioner Has Burden of Persuasion on Real Party in Interest Under 35 U.S.C. § 312(a), an IPR petition must identify “all real parties in interest,” and, an IPR petition is time-barred under 35 U.S.C. § 315(b) if “filed more than 1 year after the date on which the petitioner, the real party in interest, or a privy of the petitioner is served with a complaint alleging infringement of the patent.” As we have discussed, PTAB decisions on whether § 315(b) has been satisfied are reviewable on appeal. In Worlds Inc. v. Bungie, Inc.... More
• Chemical Company Developing Industrial Process Had Standing to Appeal In E.I du Pont de Nemours & Co. v. Synvina C.V., No. 2017-1977 (Fed. Cir. Sept. 17, 2018), the Federal Circuit determined that the IPR petitioner, DuPont, had Article III standing to appeal an IPR final decision, although it had not been accused of infringement of patent owner Synvina’s patent, or engaged in activity that could be accused of infringement. The court explained that a controversy of sufficient immediacy and reality existed because DuPont, an avowed competitor of the patent... More