In a decision that broadens the reach of prosecution history estoppel (and thus limits doctrine of equivalents), the Federal Circuit reversed a $106 million jury verdict in Colibri Heart Valve LLC v. Medtronic CoreValve, LLC, No. 2023-2153 (Fed. Cir. July 18, 2025). The court held that prosecution history estoppel barred Colibri from asserting doctrine of equivalents infringement based solely on the cancellation of a broad claim during prosecution—even though the asserted claim itself was original and never amended. This represents a notable, but not surprising, expansion of estoppel doctrine beyond traditional claim amendments to encompass strategic claim cancellations that communicate narrowing to persons of ordinary skill in the art. [23-2153.OPINION.7-18-2025_2546584]
Top Brand LLC v. Cozy Comfort Company LLC, 24-2191 (Fed. Cir. July 17, 2025)
The Federal Circuit has rejected Cozy Comfort's $15 million verdict -- finding that its hoodie design patent was not infringed. D859,788. The case turns on prosecution history - with a holding that the patentee had disclaimed aspects of the design when distinguishing the invention from the asserted prior art.
The image here shows the Top Brand accused design (left), Cozy Comfort's patented design (right), and the White prior art (middle).
After a three-week jury trial, Top Brand was found liable for both design patent and trademark infringement, with the jury awarding $15.4 million for design patent infringement and $3.08 million for trademark infringement of "THE COMFY" mark. The district court denied judgment as a matter of law, but the Federal Circuit reversed on both counts.
The Federal Circuit continues to grapple with fundamental questions surrounding the USPTO’s broad discretionary authority to deny Inter Partes Review (IPR) petitions. Both implementation issues by former Director Vidal as well as the about-change by Acting Director Stewart.
In two recent posts, I discussed the pending In re SAP, 25-132 (Fed. Cir. 2025), mandamus action that challenge the "retroactive" actions by Director Stewart -- particularly rescinding the 2022 "Vidal Memo," which had provided explicit safe harbors for IPR petitions to avoid discretionary denials. SAP argues that Stewart’s reversal constitutes an unlawful retroactive policy shift, violates due process, and exceeds administrative authority. Several new briefs opposing mandamus have now been filed in the case, with the USPTO's response expected July 21, 2025, following an extension.
This dispute hinges upon the USPTO’s internal guidance documents governing discretionary denials of IPR petitions under the Fintiv framework, originally developed in PTAB precedent under Director Iancu (favoring patentees) and later modified by Director Vidal (favoring petitioners). SAP relied on Vidal’s 2022 guidance, which offered two clear safe harbors: (1) a broad Sotera stipulation in which petitioners agree not to pursue overlapping invalidity grounds in parallel litigation, or (2) a petition presenting a “compelling” case for invalidity. The rescission announced by Chief Judge Boalick in early 2025 withdrew these safe harbors and ultimately expanded upon the original NHK-Fintiv factors to include additional justifications for discretionary denials. The new approach was then retroactively applying to pending petitions such as SAP’s that included a Sotero stipulation. After initially meeting the standards set under Vidal’s memo, SAP’s petition was nevertheless denied under the revived, broader factors. The PTAB specifically rejected SAP’s stipulation as insufficient, stating that SAP could still raise "system" prior art defenses not covered by the stipulation in parallel district court litigation, thus undermining judicial economy and efficiency.
In Alexander Milburn Co. v. Davis-Bournonville Co., 270 U.S. 390 (1926) [46_S.Ct._324], the Supreme Court established what has expanded into foundational patent law principle: all disclosures in an issued patent (whether claimed or unclaimed) serve as prior art against later filed patents, effective as of the earlier patent's filing date rather than its issue date. This doctrine of "springing prior art" emerged from a dispute over welding and cutting torch technology, where the Court held that John Whitford's asserted patent (US1028410) for an oxy-acetylene cutting apparatus was invalid because Clifford had, a few months earlier, filed a patent application that fully disclosed the same invention—even though Clifford did not claim the features patented by Whitford. Justice Holmes, writing for a unanimous Court, reasoned that allowing Whitford to "profit by the delay" of the Patent Office in processing Clifford's application would undermine the fundamental requirement that a patentee must be the "first inventor." I wanted reach back to this old case to highlight how deeply the Milburn doctrine has influenced modern patent prosecution and litigation strategies. The principle of "springing prior art," articulated 99 years ago, now significantly shapes patent law practice.
The Federal Circuit's decision in Shockwave Medical, Inc. v. Cardiovascular Systems, Inc., No. 2023-1864 (Fed. Cir. July 14, 2025) makes good on the court's overly-semantic approach to defining the "basis" of inter partes review proceedings -- especially with reference to applicant-admitted-prior-art (AAPA). Recall that under 35 U.S.C. § 311(b) IPRs can be filed "only on the basis of prior art consisting of patents or printed publications."
The court's approach in Shockwave turned on whether the petitioner labelled its prior art evidence as "basis" versus "reference." In my opinion, this formalistic undermines the IPR system and suggests additional gamesmanship. Here, it produced what I see as an absurd result - where evidence supplying a claim limitation is not deemed a "basis" of the legal challenge.
In 2025, the USPTO’s Acting Director Coke Morgan Stewart began implementing a new bifurcated and expanded process for PTAB trial institution decisions -- with a particularly enhanced focus on discretionary denials before a PTAB panel even considers the merits. This past week, several dozen new discretionary denials were released. These new decisions primarily focus on two justifications for denial:
The status of parallel litigation, especially the proximity of a scheduled district court trial to the PTAB’s projected final written decision date; and
The “settled expectations” arising from a patent’s long time in force.
In each case, the decision states a holistic "totality of the evidence and arguments” approach, but in most cases these two factors were the keys.
Perhaps most notable among recent decisions is the Director’s increasing reliance on the concept of "settled expectations." This factor refers to the notion that patent owners and market participants have some reliance interest based upon the fact that the patent that has remained unchallenged for a significant period.
Before digging into this en banc petition, I just wanted to note that patent eligibility issues have been almost shockingly quiet over the past six months. But, to me it feels something like a powder keg waiting to explode. While Acting Director Stewart has been incredibly active on other fronts since taking the helm in January 2025, she has remained notably silent on Section 101 reform initiatives. I believe there is some likelihood that this will change once John Squires is confirmed by the U.S. Senate -- given that he has already signaled support for patent eligibility reform measures like the Patent Eligibility Restoration Act (PERA).
Back to the case: In Longitude Licensing Ltd. v. Google LLC, No. 2024-1202 (Fed. Cir. Apr. 30, 2025), the Federal Circuit affirmed a N.D. Cal. dismissal of infringement claims under 35 U.S.C. § 101, holding Longitude’s asserted image processing patents were directed toward digital image processing. Longitude’s patents (U.S. Patents Nos. 7,668,365, 8,355,574, 7,454,056, and 7,945,109) cover methods of identifying a primary object within an image and adjusting image characteristics based on the object’s properties. The panel, consisting of Judges Lourie, Dyk, and Chen, determined that representative Claim 32 of the ’365 patent recited only generic, functional limitations without adequately describing how these limitations achieved the purported technological improvements.
32. An image processing method comprising:
determining the main object image data corresponding to the main object characterizing the image;
acquiring the properties of the determined main object image data;
acquiring correction conditions corresponding to the properties that have been acquired; and
adjusting the picture quality of the main object image data using the acquired correction conditions;
wherein each of the operations of the image processing method is executed by an integrated circuit.
Longitude has now petitioned the Federal Circuit for rehearing en banc, asserting that the panel improperly isolated the claim language from the specification and ignored evidence that the claimed methods improved computer functionality itself. The en banc petition frames the question presented as whether courts may determine patent eligibility under § 101 by analyzing claim language alone, divorced from supporting specification evidence, particularly where the specification describes specific technological improvements. The Federal Circuit has shown some interest in the case - requesting responsive briefing from Google, which is due in Mid-July 2025. [Longitude Licensing En Banc Petition].
In 2020, Sonos sued Google in the N.D. of California, asserting two “zone scenes” wireless speaker patents (US 10,848,885 and 10,469,966) that allow for overlapping groups of speakers. A jury found Google liable and awarded $30 million in damages. In an unusual move, District Judge William Alsup threw out the verdict in a 55-page post-trial order. He held the patents unenforceable for prosecution laches and invalid for lack of written description support. Judge Alsup found Sonos had engaged in a “daisy chain” continuation strategy to keep the patent family alive for over 13 years. Although longer than average, this timeline is not long for a patent family recognized as valuable. But, one quirk is that the particular “overlapping zone scene” claims were not presented in claim form until 2019. And, they were added after Google began selling products with that feature. Judge Alsup also concluded that Sonos’s 2019 amendments were directed to new matter not supported by the original 2006–2007 applications -- i.e., lacking written description suport. Without that priority claim, those earlier filings became anticipatory prior art to the later would-be continuation.
The appeal is now pending, and the Federal Circuit held oral arguments on July 10, 2025. The case raises fundamental questions about the scope of the "sparingly applied" doctrine of prosecution laches and also about the proper procedure for raising written description/anticipation issues during trial.
I believe that a typical Federal Circuit panel would side with the appellant Sonos. But, the panel in this case is somewhat unique. The combination of Judges Prost and Lourie creates an interesting dynamic given their opposing positions in the 2010 prosecution laches case of Cancer Research. Judge Prost's dissent in that case shows her willingness to apply prosecution laches. Although Judge Lourie did not find laches in Cancer Research, he is Judge Lourie authorship of Symbol v. Lemelson—the decision that revived prosecution laches in 2005.
In ratings of "patent friendliness" (including one by Google's attorney Dan Bagatel), Judges Prost and Lourie are among the three least patent-friendly judges on the Federal Circuit. Judge Bumb, sitting by designation from the District of New Jersey, adds unpredictability as she lacks the extensive patent law track record of her colleagues. All three are Republican appointees who generally embrace textualist approaches, but that judicial philosophy matters less here since prosecution laches is an entirely judge-made equitable doctrine with minimal congressional guidance beyond Section 282's broad authorization of equitable defenses.
The Federal Circuit is now confronting a second major mandamus petition challenging the USPTO's major changes with regard to its approach to discretionary denials in inter partes review proceedings. In re Motorola Solutions, Inc., No. 25-134 (Fed. Cir. 2025). Motorola presents an even more procedurally compelling challenge to Acting Director Stewart's retroactive system changes than the earlier In re SAP petition I discussed previously. While both cases attack the same underlying agency action, Motorola's petition benefits from having actually obtained PTAB institution decisions before they were subsequently vacated, creating a more concrete harm from the retroactive policy change.
Today the Federal Circuit is hearing oral arguments in Google v. Sonos on the doctrine of prosecution laches. The panel is interesting and has the potential of resulting in a pro-Google decision. Federal Circuit Judges Prost and Lourie, along with D.N.J. District Court Judge Renée Marie Bumb, sitting by designation.
Judge Lourie authored the Symbol v. Lemleson decision that revived the doctrine back in 2005. More interestingly, Judge Lourie wrote the opinion in Cancer Research Tech. Ltd. v. Barr Laboratories, Inc., 625 F.3d 724 (Fed. Cir. 2010), with Judge Prost in dissent. In that case, the majority found no laches, but Judge Prost would have found the patent unenforceable due to prosecution laches.
The Federal Circuit's decision in Janssen v. Teva narrows the scope of the overlapping-range presumption of obviousness, holding that when a patent claim involves an integrated, time-dependent sequence of steps rather than a simple selection of numeric values, courts must conduct a full obviousness analysis instead of applying the presumption that overlapping ranges are obvious.
The upcoming Supreme Court petition in Lynk Labs, Inc. v. Samsung Electronics Co., 125 F.4th 1120 (Fed. Cir. 2025), presents more than just another dispute about inter partes review scope. In my mind, it highlights a fundamental conceptual tension that has largely gone unnoticed in patent law discourse: the ambiguity in what we mean by "prior art" itself. This manifests as a clash between two competing frameworks that I call "prior art as document" versus "prior art as process." This distinction is crucial because it explains why seemingly straightforward statutory language in 35 U.S.C. § 311(b) becomes so contentious when applied to the "secret" or "springing" prior art under § 102(a)(2).
In Lynk Labs, the Federal Circuit held that a patent application filed by a competitor but kept secret until after the challenged patent's filing date could be used as prior art in an IPR proceeding. Samsung had successfully challenged Lynk's patent using an earlier-filed patent application (the "Martin" reference) that was filed in April 2003—months before Lynk's February 2004 priority date—but did not publish until October 2004, well after Lynk's filing. The court concluded that this reference satisfied § 311(b)'s requirement that IPR challenges be based on "prior art consisting of patents or printed publications" because the prior application had, by the time of the IPR, become a "printed publication" and § 102(a)(2) independently established its prior art status. Although 102(a)(2) does not define a "prior art . . . printed publication," it does create "prior art," and the documentary evidence is a "printed publication."
Guest post by Paul R. Gugliuzza & Jacob S. Sherkow
An important recent development in pharmaceutical patent law is the Federal Circuit’s embrace of a theory we call, in a forthcoming article, infringement by drug label. In several decisions since 2021, the court has approved claims of induced infringement against generic drug companies simply because (i) the generic’s product label could be read to contain a patented method-of-use and, in some cases, (ii) the generic stated that its product is an FDA-equivalent to the brand’s.
There are several problems with holding generic companies liable for inducing doctors (or patients) to perform a patented method of use based on a court’s (or, sometimes, an expert witness’s) interpretation of the generic’s label and the generic’s unremarkable—and often, legally required—statements about equivalence. (more…)
During claim construction proceedings, The patentee Egenera and defendant Cisco disputed several claim terms including "computer processor/processor" and aspects of "emulate Ethernet functionality over the internal communication network". However, "neither party asked the district court to determine what the patent specifically means by 'emulate Ethernet functionality,'" content to leave this key term to its "plain and ordinary meaning." This strategic choice ultimately proved fatal when the case reached summary judgment. The district court found that Cisco's CPUs "used" Ethernet functionality but found no evidence of emulation, concluding that "use of a communications network is not emulation of the functionality of that network."
The pending Radian Memory case could fundamentally reshape patent litigation. This is a follow-on article about the preliminary injunction motion in Radian Memory v. Samsungpending before Judge Gilstrap in the Eastern District of Texas. The patentee-plaintiff is a non-practicing entity -- but still argues that it has a right to injunctive relief based upon traditional equitable principles, even under the requirements of eBay. In June, the DOJ and USPTO filed a statement of interest in the case supporting the availability of injunctive relief as pro-competitive. Both sides have now provided additional arguments with a July 16 evidentiary hearing scheduled. Radian particularly argues that the recent Supreme Court cases of Trump v. CASA, Inc., 24A884, 602 U.S. ___ (June 27, 2025) and Mahmoud v. Taylor, 24-297, 602 U.S. ___ (June 27, 2025), reaffirm that the key source of law should be founding-era equity practices. The key sticking point for NPE injunctive relief is irreparable harm -- and Radian's point is that the founding era cases are clear that ongoing infringement of a property right inherently causes irreparable harm.
Radian’s argument has some legs -- and would be a major transformation if successful. Almost certainly, the “principles of equity” in 35 U.S.C. § 283 incorporate the historical practices of English Chancery and the Founding era. Although eBay has been read as eliminating any presumption of irreparable harm due to ongoing infringement, that result is only implied by the case. eBay itself made historical errors that make it difficult to know whether the court intended to apply a straight historical analysis, or one that is more fictionalized.
Acting Director Coke Morgan Stewart has been incredibly active in reshaping the PTAB's approach to IPR discretionary denials. This post focuses on her newly implemented "settled expectations" doctrine that treats patent age as a primary factor for denying institution. This new framework was formalized in the March 26, 2025 "Interim Process for PTAB Workload Management" memorandum and subsequently applied in a series of Director Discretionary Denial decisions in June 2025. The doctrine creates a temporal shield for older patents and calls forth some interesting parallels to existing doctrine, including laches and trademark incontestability.
This post digs into the pending mandamus action In re SAP. In the case, SAP raises a constitutional challenge to Director Stewart's aggressive discretionary denial approach -- as a violation of both due process and separation of powers.
The IPR statute provides the USPTO Director virtually unreviewable authority to grant or deny inter partes review (IPR) petitions. As part of the initial implementation of the IPR system, then USPTO Director Dave Kappos delegated authority to the PTAB to make those determinations. But, Acting Director Coke Morgan Stewart has substantially shifted the practice in recent months by substantially expanding the scope of discretionary institution denials -- these are refusals to institute IPRs even when the petition raises a substantial enough patentability challenge. Under Director Vidal, one important approach avoid discretionary denial was the Sotera safe harbor, stemming from Sotera Wireless, Inc. v. Masimo Corp.. In Sotera, the petitioner stipulated that it would not pursue in the parallel litigation any invalidity ground that it could raise in the IPR, thus eliminating most potential overlap in issues between the IPR and any parallel litigation. This broad stipulation (often called a “Sotera stipulation”) became a de facto safe harbor that was then formally embraced by a 2022 memorandum by Director Kathi Vidal. That memo clearly stated that the the Board would not discretionarily deny institution” in two key situations: (1) when the petitioner agreed to a broad Sotera stipulation (foregoing any invalidity arguments in court that could have been raised in the IPR), despite ongoing parallel litigation, or (2) when the petition presented a “compelling” unpatentability challenge. This interim guidance operated as binding agency internal policy that curbed Fintiv denials and reassured petitioners that certain bright-line safe harbors would be respected. The result was a substantial decrease in discretionary denials.
Fast forward to 2025 and dramatic policy changes by Acting Director Coke Morgan Stewart substantially increasing discretionary denials. In particular, Stewart rescinded the June 2022 Vidal memo and ultimately reinstated the broader pre-2022 Fintiv framework. A Sotero stipulation is no longer sufficient to avoid discretionary denials, and Director Stewart has more recently expanded the justifications for discretionary denials, including "settled expectations" where the patent issued 7+ years ago and was not challenged during that interim.
Importantly for SAP, this policy change was applied immediately and retroactively to pending cases. In other words, IPR petitions filed while the Vidal Memo was in effect could still be decided under the new more expansive discretionary denial regime, as long as the PTAB had not yet instituted by the time of the rescission. This is precisely what happened to SAP.
This week the Supreme Court granted certiorari in Cox Communications, Inc. v. Sony Music Entertainment, No. 24-171, while denying the competing petition in Sony Music Entertainment v. Cox Communications, No. 24-181. This grant/deny pair follows the Trump Administration’s Solicitor General recommendation and sets up another major Supreme Court battle over the scope of contributory copyright infringement–this one focusing on how internet service providers handle allegations of user piracy.
The case centers on fundamental questions about when companies can be held liable for their users’ copyright infringement—issues that parallel similar debates in patent law regarding inducement under 35 U.S.C. § 271(b) and contributory infringement under 35 U.S.C. § 271(c). Patent and copyright cases share common purposes and a core tension of how to hold those who facilitate infringement accountable without stifling innovation or access.
The Sony v. Cox litigation began when a consortium of record companies and music publishers sued Cox Communications, an internet service provider with millions of customers, for copyright infringement based on actions by Cox’s subscribers during 2013-2014. During this period, anti-piracy company MarkMonitor sent Cox over 160,000 automated notices alleging that specific IP addresses on Cox’s network were being used to share particular copyrighted music via peer-to-peer networks like BitTorrent.
Cox had implemented what it called a “graduated response program” under which repeat infringers would receive escalating consequences: email warnings, temporary suspensions, and ultimately possible termination. However, Cox’s application of this policy was admittedly inconsistent. Over the relevant period, Cox terminated only 33 subscribers for copyright violations while terminating over 600,000 for nonpayment. Internal emails showed Cox employees expressing frustration with the volume of infringement notices and resistance to aggressive termination policies that would cost the company subscriber revenue. (more…)
Eye Therapies v. Slayback offers a concerning example of the Federal Circuit departing from well-established patent claim construction doctrine. In this case, the court abandoned the standard interpretation of the transitional phrase "consisting essentially of" after finding that the patentee's prosecution statements created sufficient grounds to narrow claim scope. As I explain below, in my opinion, this result conflicts with the court's own Ecolab precedent and threatens to shift claim-transition interpretation from its traditional position as a canon of claim construction.
In an “informative” decision addressing the limits of multiple IPR petitions, Acting USPTO Director Coke Morgan Stewart granted Director Review and vacated the PTAB’s institution of two IPR proceedings challenging the same patent claims. CrowdStrike, Inc. v. GoSecure, Inc., IPR2025-00068, IPR2025-00070 (USPTO June 25, 2025). The Director found that the Board abused its discretion by allowing CrowdStrike to pursue two separate IPR proceedings against the same claims of Patent 9,954,872 B2, where the primary difference between the petitions was alternative constructions of a single claim term. The Director’s opinion states that allowing multiple petitions based solely on alternative claim constructions “effectively expands the permitted word count and places a substantial and unnecessary burden on the Board and the patent owner.” On remand back to the PTAB, the parties are instructed to submit claim construction briefs in order to allow the Board to consider moving forward with an IPR.
Interestingly, this remand may give the petitioner exactly what it wants in this case – room to make the alternative arguments within a single IPR petition. (more…)
