Our Patent Case Summaries provide a weekly summary of the precedential patent-related opinions issued by the Court of Appeals for the Federal Circuit and the opinions designated precedential or informative by the Patent Trial and Appeal Board.
Seagen Inc. v. Daiichi Sankyo Co., Ltd., et al.
Nos. 2023-2424, 2024-1176 (Fed. Cir. (E.D. Tex.) Dec. 2, 2025). Opinion by Lourie, joined by Reyna and Chen.
Seagen sued Daiichi and others for infringement of patent claims directed to an antibody-drug conjugate (ADC) for cancer treatment. The patent issued from a continuation of an application originally filed in 2004. The 2004 application describes an ADC with the same general formula as the issued patent but does not explicitly disclose a “Gly/Phe-only tetrapeptide” as required by the asserted claims.
At trial, the parties disputed both infringement and validity, including whether the 2004 application provided written description support for a Gly/Phe-only tetrapeptide. A jury found that the asserted claims were not invalid for lack of written description or enablement, that the defendants willfully infringed at least one claim, and that Seagen was entitled to damages of more than $41 million. Daiichi then moved for judgment as a matter of law (JMOL) but the district court denied the motion and entered final judgment for Seagen. Daiichi appealed.
On appeal, the Federal Circuit reversed the district court’s decisions on written description and enablement. As to written description, the Federal Circuit ruled that the patent’s disclosure of a “broad genus, without more, is inadequate to satisfy the written description requirement for claims directed to a particular subgenus or species contained therein.” The 2004 priority application broadly disclosed peptide units—including over 47 million different tetrapeptide units—but did not provide “reasonably specific supporting disclosure” for the claimed 81-member subgenus of Gly/Phe-only tetrapeptide linkers. As the court emphasized, the specification must “single out” the claimed invention with adequate “blaze marks.” The court’s conclusion was bolstered by admissions from the named inventors “that they had never contemplated an ADC with a Gly/Phe-only tetrapeptide as of the 2004 application’s priority date.”
As to enablement, the Federal Circuit reiterated that, to be enabling, a patent specification “must teach those skilled in the art how to make and use the full scope of the claimed invention without undue experimentation.” It was undisputed that ADC science “was so unpredictable that a skilled artisan would be required to use an assay to test whether any given ADC with a given drug moiety meets [the claimed] functional limitation.” And the court determined that “a skilled artisan would be left to perform far-ranging ‘trial-and-error discovery’ to make and use the ADCs within the scope of the [asserted] patent.” The Federal Circuit thus held that, “under these circumstances, where the scale of trial and error is so vast and the science so unpredictable, such experimentation is undue.”
The Federal Circuit therefore reversed the district court’s denial of JMOL that the patent is not invalid for failure to meet the written description and enablement requirements, and the court vacated the jury’s finding of willful infringement and assessment of damages.
In re: Gesture Technology Partners, LLC
No. 2025-1075 (Fed. Cir. (PTAB) Dec. 1, 2025). Opinion by Lourie, joined by Bryson and Chen.
Gesture owns a patent directed to “a method and apparatus used to enable rapid TV camera and computer based sensing of objects and human input for use in various applications, including handheld devices, cars, and video games.” Samsung initiated ex parte reexamination of all claims in the patent. While the reexamination was pending, so too were two IPR proceedings. The IPRs resulted in all claims except dependent claims 11 and 13 being held unpatentable.
As to these two remaining claims, an examiner rejected both as anticipated, and the Patent Trial and Appeal Board affirmed. Gesture appealed, raising three issues.
First, Gesture argued that the Board erred in determining that estoppel under 35 U.S.C. § 315(e)(1)—which generally prevents parties from re-litigating issues that were or could have been raised in an IPR—did not apply to the ongoing ex parte reexamination proceeding. The Federal Circuit disagreed. The court explained that, under § 315(e)(1), “the petitioner in an [IPR] … may not request or maintain a proceeding before the Office” on certain grounds after an IPR decision issues. The Federal Circuit held that “the petitioner does not maintain the proceeding”; “rather, the Patent Office does.” Thus, the court concluded that “the estoppel provision of 35 U.S.C. § 315(e)(1) is inapplicable against the Patent Office to ongoing ex parte reexamination proceedings.”
Second, Gesture challenged the Board’s finding that claims 11 and 13 were anticipated. The Federal Circuit affirmed because substantial evidence showed that the prior art disclosed all limitations of both claims, including the means-plus-function requirement for controlling a function of the apparatus using position or movement information. The court agreed with the Board’s claim construction and analysis of the prior art.
Third, Gesture argued that the Board lacked jurisdiction to invalidate the claims because the patent had expired. The Federal Circuit noted that it had previously rejected similar arguments with respect to IPRs because a patentee “maintains some rights, such as the right to bring an action for past damages after its patent expires, thus creating a live case or controversy, which can be adjudicated by an IPR and in proceedings before this court on appeal.” The court saw no reason why ex parte reexamination proceedings should be viewed differently.
Accordingly, the Federal Circuit affirmed the Board’s decision invalidating claims 11 and 13.
Adnexus Inc. v. Meta Platforms, Inc.
No. 2024-1551 (Fed. Cir. (W.D. Tex.) Dec. 5, 2025). Opinion by Stark, joined by Prost and Taranto.
Adnexus sued Meta for infringement of a patent directed to systems and methods for online advertising that delivers targeted ads based on user preferences. Adnexus asserted that Meta’s “Lead Ads” product infringed at least claim 1. After Adnexus filed an Amended Complaint, Meta moved to dismiss it for failure to state a claim.
The district court granted Meta’s motion to dismiss, finding that Adnexus failed to plausibly allege that Lead Ads satisfied claim limitation [1f], which requires retrieval of a user profile comprising “delivery method preferences.” For this limitation, the Amended Complaint pointed to users’ contact information in the Lead Ads. The district court concluded, however, that “contact information is sufficiently distinct from [the claimed] delivery method preferences such that contact information cannot be a delivery method preference.” The court thus dismissed the Amended Complaint, and Adnexus appealed.
On appeal, Adnexus argued that the district court erred in finding that the Amended Complaint failed to plausibly allege Lead Ads practices limitation [1f]. The Federal Circuit agreed. In particular, the Federal Circuit disagreed with the district court’s view that its analysis did not require claim construction: “That Meta and the district court had a narrower view of the scope of the claims confirms that Meta’s argument for dismissal is a claim construction argument.”
The Federal Circuit ruled that the district court “implicitly” construed “contact information” as “sufficiently distinct from delivery method preferences” so as to render Adnexus’ allegations implausible, and in doing so erred. Although district courts “have wide latitude in how they conduct the proceedings before them, including claim construction proceedings,” the district court’s discretion “did not include the option of implicitly construing the disputed claim term against Adnexus, the non-moving party, without first giving Adnexus the opportunity it requested to be heard on the issue of the proper construction of this term.”
The Federal Circuit explained that the Amended Complaint’s factual allegations about limitation [1f] “must be taken as true” at the motion to dismiss stage. Because the allegations were “sufficiently specific and factual to constitute well-pled allegations, they must be credited.” Thus, the Federal Circuit vacated the district court’s dismissal and remanded for further proceedings.