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  • PTAB § 101 Appeal Stats for 2024: The More Things Stay the Same, the Worse They Remain

    By Michael Borella and Walter DeGroft[1] –

    USPTO SealEach year since 2021, we have examined how the U.S. Patent and Trademark Office Patent Trial and Appeal Board (PTAB) has been deciding appeals of § 101 rejections from examiners.[2]  And so far, the numbers have been remarkably similar.  2024 was no exception — applicants continued to face affirmance rates that were not only very high, but stubbornly consistent with prior years.  The story here is not one of progress or meaningful change, but of inertia where an entrenched status quo provides predictability by denying patents for a wide range of inventions.

    The overall affirmance rate for 2024 was 88.6%.  As shown below, this is in line with affirmance rates from previous years.

    Table 1
    Put another way, about 7 out of 8 appeals from examiner rejections on grounds of § 101 in 2024 were affirmed by the PTAB.  Conversely, the likelihood of a successful PTAB 101 appeal is 11.4%.  This is approximately the same chance of flipping a coin 3 times and getting no heads (12.5%), the rate of left-handedness in the U.S. (~10%), or your cat coming when you call it (scientifically unverifiable but feels about right).

    The persistently high affirmance rate of § 101 rejections at the PTAB is best understood as a direct consequence of the Supreme Court's decision in Alice Corp. v. CLS Bank.  The two-step framework articulated in Alice provides little concrete guidance for practitioners, examiners, or judges.  The Court deliberately avoided defining what constitutes an "abstract idea" or when an "inventive concept" suffices to transform such an idea into patent-eligible subject matter.  This vagueness has left lower tribunals and the USPTO with a test that is inherently malleable.

    The Federal Circuit's subsequent case law has not resolved the ambiguity.  Instead, it has produced a patchwork of inconsistent precedents, where eligibility may hinge on subtle distinctions that are difficult to reconcile.  Cases such as Enfish v. Microsoft and McRO v. Bandai suggest that claims directed to specific technological improvements can survive § 101 scrutiny, while decisions like Electric Power Group v. Alstom or ChargePoint v. SemaConnect represent how readily claims can be characterized as unpatentably "abstract."  The result is a body of law where outcomes depend heavily on framing and analogy, not clear statutory or judicial criteria.

    While individual examiners at the USPTO apply § 101 in a notoriously inconsistent and personalized fashion, the PTAB consistently errs on the side of ineligibility.  The PTAB's affirmance rate is thus less a reflection of the merits of applicants' arguments and more a predictable byproduct of an eligibility test that lacks objective criteria and is skewed against applicants.  The USPTO's recent subject matter eligibility memo merely reiterates the vagueness of the test, failing to provide anything close to a clear distinction between eligible and ineligible inventions.[3]

    In any event, our data gathering process was as follows.  From the PTAB's search interface, we specified the following criteria:  decision dates between January 1, 2024 and December 31, 2024, a proceeding type of "appeal", a decision type of "decision", and an issue type of "101".  These search results were overinclusive and thus required filtering and a degree of manual review.

    We only included decisions in which the applicant appealed an examiner's Alice-based § 101 rejection and the PTAB ruled on this basis of appeal.  To simplify the analysis, we considered a decision to be an "affirmance" of the examiner's § 101 rejection if the PTAB held at least one claim invalid under § 101.  Excluded cases where those in which: (i) the appeal was not of a § 101 issue but the PTAB set forth a new grounds of rejection based on § 101, and (ii) the appeal was of a § 101 issue but the PTAB did not decide the case on § 101 grounds (e.g., the examiner withdrew the § 101 rejections after the appeal was filed).  This gave us 692 qualifying appeals, of which 613 resulted in affirmance on § 101 grounds.

    In addition to the abysmal overall affirmance rate of 88.6%, we broke the data down by USPTO technical center (TC).  For sake of comparison, we also included corresponding data from 2023 and 2022 in the table below (click on table to enlarge).  To provide a sense of scale, entries in italics are for technical centers with 40 or more 101 appeals for that year.

    Table 2
    As expected, TC3600, where most business method inventions submitted to the USPTO land, continues to have the majority of appeals (488 of 692) as well as the worst affirmance rate.  This shows that appeals from this TC are for applications that the PTAB treats as virtually per se ineligible.  TC3700, which also handles some business methods, is nearly as bad, reinforcing the point that the PTAB views any claim drawn to so-called "non-technical" features as almost certainly doomed.  But high affirmance rates are evident across nearly all art units in which software-implemented inventions are examined, and even life sciences inventions are far from safe.  The persistence of these numbers year after year confirms that the PTAB's application of § 101 is not a matter of discretion or shifting doctrine, but a structural feature of an unworkable test.

    Another set of factors we considered were the grounds under which claims were found to be abstract by the PTAB.[4]  In line with USPTO practice, a claim is "abstract" when it recites mathematics, mental steps, or methods of organizing human activity.  Of the affirmances, 18.3%, 63.9%, and 73.41% were based on these categories, respectively.  Compared to 2023's numbers of 17.3%, 46.7%, and 68.1%, we see mathematics holding steady, while there was a sharp uptick in affirmances based on the mental steps category.

    We have noticed, at least anecdotally, that the mental steps category is appearing with greater frequency in rejections of AI-based inventions.  One explanation could be that the PTAB is simply reviewing more appeals in this technology area.  The methods of organizing human activity category, which is already high, ticked up further.  AI-based inventions directed to automation of tasks previously performed by a human may be a cause of this.

    Finally, we considered situations where the applicant appeals on grounds other than § 101 (e.g., §§ 102 or 103) but the PTAB decision included a sua sponte § 101 rejection.  This occurred 9% of this time in 2024, which is consistent with the 10% of 2023.  For applicants, the practical consequence is clear.  Even if you overcome the hurdles of §§ 102 and 103 at the PTAB, there is a non-negligible chance that § 101 will be raised against you for the first time.  Such a rejection increases the cost, delay, and uncertainty for the application, and reinforces the systemic disadvantage patentees face under the current eligibility regime.

    In short, applicants faced the same uphill battle in 2024 that they did in the previous years, and nothing in these statistics suggests that the trend will change absent intervention from Congress or the Supreme Court.  As Judge Paul Michel has warned, this kind of unpredictability makes patents unreliable assets of questionable value.  The consequences fall heaviest on startups and small businesses, which depend on enforceable patents to raise capital and challenge incumbents.  The current affirmance rates all but guarantee the opposite, fortifying the position of dominant players while draining the lifeblood from emerging companies.

    [1] Walter DeGroft was a 2025 Summer Associate at MBHB.  He is currently a law student at the Chicago-Kent College of Law.

    [2] Patent Docs has published our previous articles for 2021, 2022, and 2023.

    [3] https://www.uspto.gov/sites/default/files/documents/memo-101-20250804.pdf

    [4] The vast majority of the § 101 appeals were of software, business methods, and engineering-related technologies.  Life sciences § 101 appeals were mostly based on the "law of nature" exclusion to patentability rather than the "abstract idea" exclusion.  Very few (less than 10) life sciences appeals were in this data set.

  • Judge Newman’s Challenge Fails at D.C. Circuit

    An inevitable and tragic outcome

    By Kevin E. Noonan —

    Judge Newman_1Congress in writing laws is faced with a dilemma.  On the one hand the laws must be sufficiently clear and specific to enable enforcement, but on the other, the myriad of circumstances that can arise make it impossible to delineate with sufficient prescience the multitude of situations that can fall within the scope of the statute.  Courts are the usual arbiters of how the law should be interpreted and applied, under Marbury v.  Madison and 230 years of subsequent precedent.  The question of what happens when it is the court itself whose practices and procedures are at issue has arisen in Judge Pauline Newman's challenge to her suspension under the Judicial Councils Reform and Judicial Conduct and Disability Act of 1980.  As set forth in the D.C. Circuit Court of Appeals opinion against that challenge, the Court decided that its hands were tied by the statute itself (as interpreted by the Court under McBryde v. Committee to Review Circuit Council Conduct & Disability Orders of the Judicial Conference of the United States, 264 F.3d 52 (D.C. Cir. 2001)), which held that "Congress precluded our jurisdiction over statutory and as-applied constitutional challenges to judicial council orders."  This was the decision even though in their opinion the Court states that "our reasons for affirming are unrelated to the strength of Judge Newman's statutory claim or as-applied constitutional claims.  Nor does our decision reflect our views of the underlying dispute or of Judge Newman's suspension."

    The decision was ultimately jurisdictional, the panel deciding that their jurisdiction only extended to "Judge Newman's facial constitutional challenge to the Act's case suspension provision," which failed on the grounds that the challenged provision has applications that are constitutional (a rather "all or none" approach no matter how proper).  The statutory provision purportedly tying the Court's hands, § 357(c) entitled "No Judicial Review" states that "all orders and determinations, including denials of petitions for review, shall be final and conclusive and shall not be judicially reviewable on appeal or otherwise."  Which seems not only plain on its face but to express Congress's clear intentions, upon which the D.C. Circuit panel relied in affirming the District Court's dismissal of Judge Newman's as-applied constitutional claims and statutory claim for lack of jurisdiction.

    Application of the law, and specifically § 357(c), is governed by Supreme Court precedent, particularly Webster v. Doe, 486 U.S. 592, 603 (1988), where a statutory bar to judicial review should be upheld to preclude review of constitutional claims "only if there is clear and convincing evidence'" of Congressional intent, the opinion citing Ralls Corp. v. Comm. on Foreign Inv. in U.S., 758 F.3d 296, 308 (D.C. Cir. 2014).  The panel turned to McBryde in holding that this Circuit Court of Appeals had performed this judicial analysis and found sufficiently "clear and convincing" evidence to uphold the bar to Judge Newman's constitutional challenge.  In particular, the Court in McBryde held that there was insufficient evidence of Congressional intent regarding facial challenges to the statute's constitutionality, but there was sufficient evidence to do so regarding "as applied" challenges. It was in this latter category to which the Court understood Judge Newman's challenges reside.  And the judges on the panel recognized that they are bound by the earlier decisions of the Court unless overturned by "intervening Supreme Court precedent."

    The opinion then turns to Judge Newman's arguments that the Supreme Court has effectively overruled McBryde, specifically (and fittingly) in SAS Institute, Inc. v. Iancu, 584 U.S. 357 (2018), asserting that the Supreme Court's decision "suggests that even an explicit statutory bar cannot preclude judicial review of claims that an agency exceeded its statutory authority."  (It is necessary to consider in this argument the mention in an earlier footnote that "our court has treated judicial councils and the Judicial Conference as administrative rather than judicial bodies," which makes this citation germane.)  The panel was unpersuaded by this argument, because they discerned as a distinction that in SAS the statutorily preclusion was with regard to "whether to institute an inter partes review" (emphasis in opinion) whereas the challenge was directed to "how the Director conducted his inter partes review" and thus outside the scope of the challenged statutory provision (35 U.S.C. § 314(d)).

    The panel also rejected Judge Newman's argument that the addition of a severability clause to the statute in 2002 "expressly contemplates 'as applied' challenges to the Act being adjudicated in Article III courts," if only because its scope was generic and did not state that an Article III court could consider as-applied challenges.  Nor did the panel agree that the failure of the Judicial Conference to consider constitutional issues undermined the reasoning in McBryde's that the Judicial Conferences themselves could or would consider these issues (the panel recognizing that the Judicial Conference here pointedly declined to consider Judge Newman's constitutional challenges).

    Finally, the Court refused Judge Newman's recourse to Axon Enterprise, Inc. v. FTC, 598 U.S. 175 (2023), and Free Enterprise Fund v. Public Company Accounting Oversight Board, 561 U.S. 477 (2010), to the extent that Judge Newman argued those cases "held that all constitutional questions 'are outside the scope of agencies' expertise' and so must be reviewable in federal courts."  But "neither case involved an explicit jurisdiction-stripping provision like Section 357(c)" (emphasis in opinion); in those cases the preclusion was implied according to the Court, and in such cases the standard is not a clear and convincing evidence of Congressional intent.

    The opinion then addresses the deficiencies of Judge Newman's reasoning to as-applied challenges.  These included a footnote in McBryde that the Judge contended evinced an opinion that a court would have jurisdiction over as-applied challenges should they arise.  This opinion terms this reading of McBryde to be "implausible" in view of the remainder of the McBryde opinion. Similarly the panel dismissed Judge Newman's argument that McBryde (nor the statute) did not preclude her due process claims or the Judicial Conference's refusal to transfer her case to a different circuit, because "Judge Newman may be right that the Act provides no means to petition the Conference for interlocutory review of the Council's transfer decision.  But the Act does provide for Conference review of any final council action stemming from a case that was not transferred," which Judge Newman unsuccessfully attempted to employ.

    Having explained the portions of Judge Newman's arguments over which the Court did not have jurisdiction the opinion turned to those that it does, the Judge's facial challenge to the statute's case-suspension provisions.  The panel acknowledges the difficulty in prevailing in such challenges.  The most determinative of these difficulties is Judge Newman's acknowledgment that there are applications of the statute that pass constitutional muster, where a facial challenge demands that there be no such circumstances or applications.  In this portion of the opinion, the Court sets forth those concessions and their effect on the Judge's arguments, including that "short suspensions from receiving new case assignments" are constitutional under certain circumstances.  But Judge Newman has not been able to show "no set of circumstances . . . under which the law would be valid" or that it "lacks a plainly legitimate sweep," citing Comm. on Ways & Means v. Dep't of Treasury, 45 F.4th 324, 339 (D.C. Cir. 2022).  And ("indeed") the panel appreciates that Judge Newman did not attempt to make this showing, rather arguing that how the statute was applied to her was unconstitutional.  Somewhat unkindly, the opinion states that the Judge's argument "misunderstands the law governing facial constitutional challenges" at least in this context (begrudging that in other contexts, such as the First Amendment, "statutes may sometimes be deemed facially invalid where only a subset of their applications are unconstitutional," citing United States v. Hansen, 599 U.S. 762, 769 (2023), and stating that this is a special case due to the importance of constitutionally protected speech).  The Court also dismissed Judge Newman's invitation to adopt a "narrowing construction" of the statute because in order to properly do so the panel states that first Judge Newman would have had to raise "a serious constitutional question," which, in their view, Judge Newman has not done.

    The opinion ends with two points the panel sought to emphasize.  The first is that they did not (and assert that they could not) consider the merits of Judge Newman's as-applied constitutional claims.  In an apparent nod towards the respect Judge Newman has certainly earned, the Court states that "Judge Newman has posed important and serious questions about whether these Judicial Conduct and Disability Act proceedings comport with constitutional due process principles and whether her ongoing suspension comports with the structure of our Constitution" and that their failure (or more correctly refusal) to address those questions "is no indication that her arguments lack merit, nor signals how we might have addressed them if we were able."  Their hands are tied, according to the opinion, because "precedent strips us of authority to consider those challenges," which is the only reason the panel did not address them.

    The second point is a reiteration that the panel was unable to overrule McBryde but nevertheless the Court recognizes that there are reasons to think that case was wrongly decided.  One reason is that the "seeming absence of a judicial forum to address [Judge] Newman's as-applied constitutional claims itself raises constitutional concerns."  The opinion states that "Judge Newman presents substantial arguments that her suspension—which has now lasted nearly two years, with a third year recommended—threatens the principle of judicial independence and may violate the separation of powers" as well as the due process violations Judge Newman asserted and the Court did not reach.  But as it stands under the law, Judge Newman cannot raise her as-applied constitutional arguments before any Article III court and is left at the consideration (if not mercy) of the Federal Circuit Judicial Council and Judicial Conference.

    In a footnote, the opinion speculates that Judge Newman may have the option of asking the Supreme Court to review the Judicial Conference orders under a writ of mandamus, but the Circuit Court deigned not to express an opinion on this possibility.

    Under the circumstances, it appears that Judge Newman has three options remaining:  to succumb to the demands of the Judicial Council to submit to medical and psychological testing by doctors not of her choosing; to continue in limbo under suspension; or to step down from the bench.  No one but the Judge herself can provide any relevant counsel.  But the circumstances under which the current situation has arisen and persisted can certainly and properly be decried and the Judge herself be wished Godspeed.

  • DexCom, Inc. v. Stewart (Fed. Cir. 2025)

    By Kevin E. Noonan —

    Federal Circuit SealThe Federal Circuit affirmed a decision by the U.S. Patent and Trademark Office (USPTO) Patent Trial and Appeal Board (PTAB) in an inter partes review prompted by an infringement allegation in DexCom, Inc. v. Stewart (nonprecedential).  The dispute created an opportunity for the Court to acknowledge the importance of the "expanded and flexible" approach to obviousness determinations occasioned by the Supreme Court's decision in KSR Int'l. Co.  v. Teleflex. Inc., 550 U.S. 398 (2007), and also the question of the extent to which prior art containing alternative embodiments, only one of which is relevant to obviousness requires evidence that the skilled artisan would have (not only could have) chosen the embodiment that supported an obviousness determination.

    The case arose in an inter partes review proceeding against DexCom's U.S. Patent No. 10,702,193* brought by Abbott Diabetes Care, Inc.** and asserting invalidity for obviousness against Claims 1–3 and 11–13.  The '193 patent was directed towards glucose monitoring in patients using an implantable "transcutaneous continuous glucose sensor system."  The opinion explains that the invention sought to overcome a local inflammatory response, termed a "foreign body response" that caused implanted devices to lose their function over time, by using a "barrier cell disruptive layer" configured with a number of electrode layers separated by layers of non-conductive material.  Claim 1 was set forth in the opinion as being representative:

    1.  A transcutaneous continuous glucose sensor system comprising:
        a substantially planar sensor, the sensor comprising:
            a first conductive layer associated with a first electrode;
            a first non-conductive layer located at least in part over the first conductive layer;
            a second conductive layer associated with a second electrode, wherein the second conductive layer is located at least in part over the first non-conductive layer;
            a second non-conductive layer located at least in part over the second conductive layer;
            a third conductive layer associated with a third electrode, wherein the third conductive layer is located at least in part over the second non-conductive layer; and
            a membrane located over at least a portion of a working electrode;
        wherein at least one of the first electrode, the second electrode, or the third electrode is the working electrode, and wherein the working electrode is configured to measure a signal indicative of a glucose concentration.

    The specification of the '193 contains inter alia this drawing of the claimed device:

    Image 1which is described thusly in the '193 patent:

    The sensor typically comprises a working electrode 21, a reference electrode 20, and an optional counter electrode 22. These electrodes may be insulated from each other by insulative layers 28 and further be housed in housing 10.  The reference electrode 20 provides a stable – voltage electrode relative to which the voltage of the working electrode 21 can be controlled or detected.  The optional counter electrode 22 draws the current flowing through the working electrode 20 so that the current through the reference electrode 20 is kept at a minimum, thus maintaining its voltage stability.  The end surfaces of all three electrodes are advantageously coated with membrane system 32, which may comprise a layer of glucose oxidase enzyme.  The membrane may then be coated with the barrier cell disruptive biointerface 33.

    DexCom brought suit against Abbott for infringement and Abbott petitioned for inter partes review. Abbott's obviousness challenge relied as the primary reference on U.S. Patent Application No. 2005/0215871, arguing that Figures 4A, 4B, and 2A were sufficient to establish obviousness:

    Image 2
    Figure 4A illustrates a three-electrode sensor, and Figure 2A shows a two-electrode sensor with the electrodes separated by a plastic (non-conductive) layer in a "stacked fashion."  Abbott argued that this disclosure would have been understood by the skilled worker to show that "the three conductive layers associated with the electrodes are located overtop each other in a stacked fashion," relying on expert testimony that "Figure 4A confirms the stacked arrangement because one of the electrode 'trace' lines connecting an exterior electrode to the insertion tip covers the other two trace lines."  Abbott also argued that inserting non-conductive layers between the electrodes would have been obvious in order to avoid short circuits between the electrodes.

    In its Final Written Decision, the PTAB held that all challenged claims were obvious.  The Board was convinced that Figure 4A disclosed three electrode layers "located overtop each other in a stacked fashion," reinforced by the disclosure in Figure 2A.  This appeal followed.

    The Federal Circuit affirmed, in an opinion by the Honorable Nina Y. Wang, District Judge, U.S. District Court for the District of Colorado, sitting by designation, joined by Chief Judge Moore and Judge Stoll.  The panel rejected DeCom's argument that the Board misread Figure 4A in the Feldman reference to infer that the electrode layers were stacked, and that other configurations could be inferred with equal likelihood.  This  this failure, according to DexCom should have precluded the Board's decision from being supported by substantial evidence.  The panel contended that, on the contrary this is a misreading of the Board's decision.  The opinion states that the standard is that the Board's interpretation was one interpretation relevant to the issue of obviousness of the challenged '193 patent claims, and that what was claimed in those claims was encompassed by the Feldman disclosure, crediting Abbott's expert's testimony.  The Court relied on Bradium Techs. LLC v. Iancu, 923 F.3d 1032, 1049 (Fed. Cir. 2019), for the principle that a reference should be interpreted "not only for what it expressly teaches, but also for what it fairly suggests" to a skilled artisan.  The Board properly considered, according to the panel, that "a skilled artisan would have interpreted Feldman as encompassing the stacked electrode arrangement" and that this was substantial evidence supporting the decision.  While consistent with the case law relied upon by the Court, this interpretation seems to risk hindsight reasoning without some indication that the Board's interpretation was how the skilled worker would have, not just could have, interpreted the reference this way.  It appears from the opinion that the panel believed Abbott's expert's testimony was sufficiently convincing to find substantial evidence support for the Board's decision.

    The Court also considered DexCom's arguments to be a further misreading of the Board's decision with regard to whether the Board held that Feldman disclosed the five-layer electrode configuration or just rendered it obvious (the panel also interpreting these arguments as being inconsistently argued by DexCom) (emphasis added).  The panel considered DexCom's argument to be that "an obvious but undisclosed arrangement necessarily requires modification" but because Abbott never argued a need for modifying Feldman DexCom lacked the opportunity to respond to this argument during the IPR.  In addition, DexCom complained that the "Board failed to make the requisite fact-findings regarding a skilled artisan's modification of Feldman," and thus applied an incorrect obviousness standard.  The Court agreed that "there is no such 'dichotomy' between disclosure and obviousness, and that the Board's decision d[id] not rely on modifying Feldman to achieve the claimed arrangement" to which the panel also agreed.

    The panel further interpreted the Board's decision as relying on the "expansive and flexible approach" that permits a court (or the Board) to "take account of the inferences and creative steps that a person of ordinary skill in the art would employ" under KSR Int'l. Co.  v. Teleflex. Inc., 550 U.S. at 415, 418.  It was enough according to the Board, that Feldman disclosed the five-layer electrode claimed by the '193 patent; having disclosed other "alternative" configurations did not negate this disclosure for an obviousness determination.

    Lastly, DexCom argued that the Board was incorrect for considering Figure 4A as prior art because the filed application, which was properly prior art and had fewer clear-cut drawings, qualified but the published application should not.  DexCom and the panel recognized that this would require the Court to adopt a new evidentiary rule in IPRs, but the panel was able to avoid ruling on this issue on the grounds that DexCom waived the argument by not raising it post-institution (despite having done so in its pre-institution response, citing Parus Holdings, Inc. v. Google LLC, 70 F.4th 1365, 1373 (Fed. Cir. 2023), for the rubric that "[b]y raising an argument in its Preliminary Response, but not its Response, a patent owner waives said argument").

    * The opinion recites the patent number as 10,792,193; the correct patent number is 10,702,193.
    ** As set forth in a footnote, Abbott Diabetes Care, Inc. withdrew from the appeal prior to oral argument, and Acting Director Coke Morgan Stewart intervened in the appeal, relying on Abbott's brief.

    DexCom, Inc. v. Stewart (Fed. Cir. 2025)
    Nonprecedential disposition
    Panel: Chief Judge Moore, Circuit Judge Stoll, and District Judge Wang
    Opinion by District Judge Wang

  • In re BAC IP B.V. (Fed. Cir. 2025)

    By Kevin E. Noonan —

    Federal Circuit SealA patent applicant dissatisfied by an patent examiner's rejection of that applicant's claims in ex parte prosecution has recourse by appeal to the Patent Trial and Appeal Board (PTAB) under 35 U.S.C. § 134, and to the Federal Circuit thereafter under 35 U.S.C. § 141.  While there is no right without a remedy (ubi jus ibi remedium) that remedy can be fleeting, as illustrated by In re BAC IP B.V. (non-precedential) (albeit illuminative).

    Appellant's appeal was from a decision by the PTAB affirming an Examiner's Final Rejection of claims 77-83 and 85-94 in U.S. Application No. 16/282,082* that were directed to a method for purifying mammalian immunoglobulin antibodies, for failing to satisfy the written description requirement of 35 U.S.C § 112(a). Claim 77 is representative:

    A method for the purification of a molecule comprising an epitope present in the Fc domain of a human IgG antibody, the method comprising the steps of:
        (a) bringing a sample comprising the molecule comprising the epitope present in the Fc domain of a human IgG antibody into contact with an immunoadsorbent material comprising a variable heavy-heavy (VHH) antigen-binding protein under conditions that allow for binding of the molecule to the immunoadsorbent material;
        (b) optionally, performing a washing step; and
        (c) eluting the bound molecule comprising the epitope present in the Fc domain of a human IgG antibody under conditions that decrease the affinity between the molecule and the VHH antigen-binding protein,
            [(i)] wherein the VHH antigen-binding protein has binding affinity for the Fc domain of the human IgG molecule but does not have binding activity for the Fc domain of a mouse, a bovine, a rat, a Syrian hamster, a guinea pig, a dog, a cat, a goat, or a sheep IgG molecule, and
                [(ii)] wherein the VHH antigen binding protein comprises four framework regions, FR1 to FR4, and three complementarity determining regions, CDR1 to CDR3, that are operably linked in the order FR1-CDR1-FR2-CDR2-FR3- CDR3-FR4, wherein the CDR3 region comprises the amino acid sequence Arg Arg Phe Gly Ser Ser Glu Trp Asp Tyr (SEQ ID NO: 108).

    (wherein the italicized portion of the claims raised the written description issues that were the basis for the examiner's final rejection).  The bases for the PTAB's decision (which adopted the Examiner's reasoning) were, first, that "the claims cover a large genus of VHH antigen-binding proteins"; second, that "the specification of the '082 application discloses only one VHH antigen-binding protein meeting each requirement of claim 77"; and third, that "the specification does not disclose a structural feature shared by each member of the species of claim 77."

    The Federal Circuit affirmed, in a decision by Judge Lourie joined by Judges Prost and Stoll.  The panel rejected Appellant's argument that the Board's determination was not supported by substantial evidence.  As the Court saw it, the Examiner was correct in the three bases affirmed by the Board.  Regarding the "large genus of VHH antigen binding proteins," the opinion asserts that this conclusion was based on correct claim construction which was consistent with the language of claim 77 and the specification.  The specificity of the amino acid sequences recited in claim element (c)(ii) for CDR3 of the VHH protein did not overcome the lack of such specificity for CDRs 1 or 2.  The disclosure of 49 different species of amino acid sequences for CDRs 1 and 2 in the specification also did not suffice for the panel, because the scope of claim 77 was not limited to those sequences.  The Court opined that "the claims and specification place effectively no constraints on the amino acid sequences that can constitute the CDR1 and CDR2 regions, and therefore the claimed VHH antigen-binding proteins," which supported the Examiner's conclusion that the claimed genus is broad, and was supported by substantial evidence.  The panel rejected BAC's argument that the genus was narrow because the specification only disclosed 15 VHH antigen-binding proteins defined by function and only one having the sequence recited in claim element (c)(ii).  According to the Court, the proper determination of written description satisfaction is not limited to what is disclosed in the specification but rather depends upon the scope of the claim as properly construed, which in this instance encompassed a broad genus having unspecified (and broad) amino acid sequences for CDRs 1 and 2.

    The Court also rejected BAC's arguments that the specification disclosed "how to identify VHH antigen-binding proteins" by functional and structural characteristics.  This is insufficient to satisfy the written description requirement in view of the specification only disclosing a single VHH antigen-binding protein species, according to the panel.

    The opinion also notes that "BAC does not challenge the Board's findings that the '082 application discloses only one VHH antigen-binding protein that meets each of the limitations claim of 77, and that the '082 application does not disclose a common structural feature for the claimed VHH antigen-binding proteins" as grounds for affirming the Board's rejection of BAC's appeal of the examiner's final rejection.

    The decision in many ways is a "garden variety" written description rejection based on thirty years of written description jurisprudence that began with Judge Lourie's decision in Regents of the University of California v. Eli Lilly & Co. (indeed, the decision recites the standard from that case that satisfaction of the requirement can be achieved by disclosing a "representative number of species" in a claimed genus or a structure/function relationship for species falling within the scope of the claimed genus).  If nothing else, decisions such as these illustrate the continuing consistency of the Court's written description jurisprudence.

    * The opinion notes that at least one claim would be allowable, if amended so as not to depend on a rejected base claim; that claim recited a specific VHH species.

    In re BAC IP B.V. (Fed. Cir. 2025)
    Nonprecedential disposition
    Panel: Circuit Judges Lourie, Prost, and Stoll
    Opinion by Circuit Judge Lourie

  • American Science and Engineering, Inc. v. Stewart (Fed. Cir. 2025)

    By Kevin E. Noonan —

    Federal Circuit SealUnder Dickinson v. Zurko courts (specifically, the Federal Circuit) should defer to factual determinations by administrative agencies like the U.S. Patent and Trademark Office unless they are not supported by substantial evidence, pursuant to the provisions of the Administrative Procedure Act (codified at 5 U.S.C. § 706).  Such deference is not plenary, and when the Office (or more specifically, the Patent Trial and Appeal Board) renders a decision that does not sufficiently show its reasoning regarding relevant facts to support its findings the court should, at a minimum, vacate the decision and remand with the benefit of the Court's thinking on the matter.  Such was the case in the Federal Circuit's recent decision in American Science and Engineering, Inc. v. Stewart (nonprecedential).

    The case arose in an inter partes review proceeding brought by Petitioner Viken Detection Corp., challenging the claims of American Science's U.S. Patent No. 7,400,701 on anticipation grounds over U.S. Patent No. 7,672,422 and for obviousness over the combination of the '422 patent and U.S. Patent Nos. 6,459,764 or 6,459,764.  The '701 patent was directed to an inspection system wherein an object was subjected to "multiple sources of penetrating radiation"; Claim 1 was set forth in the opinion as being representative:

    1.  An inspection system for inspecting an object characterized by motion in a direction with respect to the inspection system, the system comprising:
        a.  a first pencil-beam source for providing a first beam of penetrating radiation of specified cross-section directed in a first beam direction substantially transverse to the direction of motion of the object;
        b.  a second pencil-beam source for providing a second beam of penetrating radiation of specified cross-section substantially coplanar with, and substantially perpendicular to, the first beam of penetrating radiation, directed in a second beam direction, and temporally interspersed with the first beam of penetrating radiation;
        c.  a plurality of scatter detectors each scatter detector of which is disposed so as to detect radiation scattered from both the first beam and the second beam by any scattering material within the inspected object and for generating a scattered radiation signal; and
        d.  a controller for creating an image of the scattering material based solely on the scattered radiation signal.

    (wherein the italicized language denotes claim elements relevant to the issues between the parties).

    The PTAB found claims 1-4 and 10-13 to be anticipated by the '422 patent and claims 5-9 to be obvious under combinations of the asserted prior art.  Although Viken withdrew from this appeal before briefing had concluded, the Acting Director intervened as appellee and filed a brief responsive to American Science's appeal.

    The Federal Circuit vacated and remanded, in an opinion by Chief Judge Moore joined by Judges Linn and Cunningham.  The Court agreed with American Science's argument that the Board erred because it did not find that the "scatter detectors [disclosed in the '422 patent] can detect scattered radiation from two perpendicular pencil beam sources" as required by the '701 challenged patent claims.  The panel found that the '701 patent disclosed "substantially perpendicular" pencil beam sources that were surrounded by "a plurality of scatter detectors disposed to detect radiation scattered from the perpendicular beams."  The '422 patent, on the other hand, teaches "additional detectors" but "is silent as to whether the additional detectors detect radiation from multiple pencil beam sources"; this configuration is illustrated by this drawing reproduced in the opinion:

    Fig. 1While the panel recognized that the Board found the additional detectors were "capable of detecting backscatter radiation from both pencil beams because [the '422 patent] discloses cycling pencil beam sources such that only one source is turned on at a time," in the panel's opinion the Board "never expressly found [the '422 patent's] additional detectors detect radiation from both pencil beams when the beams are in a 'substantially perpendicular' arrangement" as claimed, and thus did not satisfy the requirements for anticipation that "every limitation in the claim was identically shown in the single reference" under Gechter v. Davidson, 116 F.3d 1454, 1460 (Fed. Cir. 1997).  The Acting Director responded to this assertion of Board error by arguing that "the '701 patent repeatedly acknowledges that radiation scatters from an object in all directions so the additional detectors detect at least some radiation from all of [the '422 patent's] pencil beam sources."  But the Court considered that the Board "made no findings about the '701 patent's disclosure of how radiation scatters that allow [the panel] to discern the path of [the Board's] reasoning," which contravenes the rubric enunciated in In re Nuvasive, Inc., 842 F.3d 1376, 1383 (Fed. Cir. 2016), that "[t]he PTAB's own explanation must suffice for us to see that the agency has done its job and must be capable of being 'reasonably . . . discerned' from a relatively concise PTAB discussion."  The Court also rejected the Acting Director's argument that the Petition and Viken's expert witness's testimony supported its determination that the '422 patent's "additional detectors would detect radiation scattered from all sources."  The opinion characterizes this argument as comprising "a citation within citation" that does not allow the Court to determine whether the Board's bases for its opinion followed the "proper path" because it amounted to "conclusory assertions and lack of explanation or reasoning."  The panel thus vacated the Board's decision because "the Board has failed to provide us with reasoning that is reviewable on appeal for its finding that [the '422 patent's] additional detectors detect scattered radiation from substantially perpendicular pencil beams" as required to support its finding that claims 1-4 and 10-13 of the '701 patent were anticipated by the '422 patent disclosure.  Without analysis the Court also vacated and remanded the Board's determination that claims 5-9 of the '701 patent were obvious, based on the same failure by the Board to explain its reasoning regarding the '422 patent disclosure.

    American Science and Engineering, Inc. v. Stewart (Fed. Cir. 2025)
    Nonprecedential disposition
    Panel: Chief Judge Moore and Circuit Judges Linn and Cunningham
    Opinion by Chief Judge Moore

  • Federal Circuit Special Committee Recommends Continued Suspension for Judge Newman

    By Kevin E. Noonan —

    Judge Newman_1Inexorable, inevitable, and regrettable are three words that come to mind with publication from the Report from Special Committee of the Federal Circuit (composed of Chief Judge Moore and Judges Prost and Taranto) containing, inter alia, their recommendation that suspension of Judge Pauline Newman be extended for yet another year.

    The basis for the sanction remains the same:  that Judge Newman's continued refusal to submit to the Special Committee's appointed physicians is judicial misconduct.  The Report is 95 pages in length and sets forth those spurned physicians' justifications for arguing that their examination (and not Judge Newman's own qualified physicians') are required.  Those arguments include that "[t]he Committee finds that this extensive record leaves no room for doubt:  Judge Newman, now 98 years old, needs a full neuropsychological battery of tests in order for the Committee to determine whether she is capable of performing the functions of an active federal judge" (the reference to the Judge's age not being close to coincidental).  The Report strongly suggests that the report by Judge Newman's physician (Dr. Rothstein) on her neurological health is less robust that presented in her attorney's arguments.  The Report also cast doubts on Dr. Carney's opinion regarding Judge Newman's neurological fitness to serve.  And the Report asserts that "[a]ll three" of the Committee's experts "explained, in detail, that, contrary to the assertions made by Judge Newman's expert, Dr. Filler, it is not an accepted diagnostic approach in the field to use a CT perfusion scan to determine whether or not an individual suffers from a cognitive impairment" (supplemented by additional allegations of professional incredibility on Dr. Filler's part, including mistakes regarding Judge Newman's fainting incidents).  The Report also includes evidence from the Judge's medical records of "memory impairment" issues as early as 2022 and that the Judge made "significant errors" in recounting her own medical history to her doctors in 2023 and 2024.

    Of the evidence and testimony from "non-professional" witnesses, the Report mentions the "more than a dozen affidavits from court employees from nearly every court department" as raising "serious concerns" regarding the Judge's neurological health.  This evidence, while helping to paint a picture of the Judge being in cognitive decline is less relevant first for being lay testimony on a medical issue for which the witnesses are not competent to opine and second because the issue is not whether prudence suggests the Judge's neurophysiological state be assessed, but rather the Committee's insistence that Judge Newman comply with their demands that their physicians do the assessing.

    The summary section of the Report ends by placing the blame for the current circumstances on the Judge, stating that "[y]ears of litigating this dispute could have been avoided if Judge Newman had acknowledged in 2023 that the neurologist she selected—Dr. Ted Rothstein—recommended that she have the more detailed neuropsychological testing and if she had followed his advice and acquiesced in having that testing."

    The Report's conclusions contain three recommendations (characterized elsewhere in the Report as "recommended sanction for continuing misconduct"):

    (i) that there is a reasonable basis to order full neuropsychological testing by a provider selected by the Committee;

    (ii) that Judge Newman's continued refusal to cooperate with the Committee's investigation by undergoing that testing constitutes continuing misconduct; and

    (iii) that the Judicial Council should renew the sanction of suspending Judge Newman from hearing cases for a period of one year.

    As Judge Newman has maintained, following these recommendations could be considered to be a de facto impeachment of an Article III judge regardless of how it is presented.

    The remainder of the Report provides an extensive recapitulation of the procedural and evidentiary background of this matter, specifically directed at evidence that casts doubt on the conclusions drawn by Judge Newman's experts, the validity of the testing they did perform, and whether they themselves evinced as much faith in those conclusions than has been represented they did in various court filings and briefs both before the Committee and in the lawsuit brought by Judge Newman in the D.C. District Court and Circuit Court (see "Judge Newman Files Appeal with D.C. Circuit").  Regarding the Committee's own experts, the Report provides their professional imprimatur on the insistence that Judge Newman submit to examination by them as "independent experts" based at least in part on the deficiencies alleged against the physicians picked by the Judge herself.  Finally, the Report attempts to rebut the anecdotal evidence by those who have heard Judge Newman speak during the term of her suspensions by stating that "[e]vidence suggesting that Judge Newman can speak coherently and fluidly does not undermine the need for testing."

    Unless the D.C. Court of Appeals finds in Judge Newman's favor it can only be presumed that she has spent her last day as an active Judge on the Federal Circuit bench.

  • Colibri Heart Valve LLC v. Medtronic Corevalve, LLC (Fed. Cir. 2025)

    By Kevin E. Noonan —

    Federal Circuit SealThe doctrine of equivalents (DOE), a creation of the Supreme Court in Graver Tank & Mfg. v. Linde Air Products (1950), is balanced by the concept of prosecution history estoppel (PHE), the contours of which were delineated over an exhaustive (eight decisions over twelve years) back-and-forth between District Courts, the Federal Circuit, and the Supreme Court in Festo Corp. v. Shoketsu Kinzoku Kyogo Kabushiki. The resulting jurisprudence expanded the scope of PHE, wherein any claim amendment during patent prosecution presumptively raised the estoppel, which prevented any additional scope for the amended claim element.  The effect of this estoppel was felt by plaintiff in Colibri Heart Valve LLC v. Medtronic Corevalve, LLC with the result that a $106 million judgment was lost.

    Colibris brought suit over its U.S. Patent No. 8,900,294, directed to methods for implanting an artificial heart valve to replace a defective valve, wherein its valve had the quality of permitting a "do-over" in cases where the valve is not initially properly positioned.  This feature, based on incomplete deployment permitted the valve to be "recaptured" and repositioned if initial positioning is not optimal.  Colibri alleged Medtronic was inducing surgeons to infringe the claimed method under 35 U.S.C. § 271(b).

    The claims as filed recited two embodiments.  In the first, the valve was pushed out of an outer sheath from the delivery apparatus, while in the second the outer sheath was retracted to expose the valve; claims to the latter embodiment were cancelled after the Examiner rejected them for failure to satisfy the written description requirement of 35 U.S.C. § 112 (a).

    The claims at issue were directed to the first embodiment; claim 1 is representative:

    1.  A method of controlled release of a percutaneous replacement heart valve at a location of a native heart valve in a patient, the method comprising:
        obtaining a replacement heart valve device and a delivery and implantation system:
        the replacement heart valve device including:
            a stent member that is collapsible, expandable and configured for percutaneous delivery; and
            a valve residing entirely within an inner channel of the stent member and attached to a proximal portion of the stent member, the valve including two to four individual leaflets made of fixed pericardial tissue;
        the delivery and implantation system including:
            a pusher member and a moveable sheath, wherein the pusher member includes a guide wire lumen, and wherein the moveable sheath includes a lumen configured for receiving the pusher member;
        after the obtaining step, loading the replacement heart valve device into the lumen of the moveable sheath such that the replacement heart valve device is collapsed onto the pusher member to reside in a collapsed configuration on the pusher member and is restrained in the collapsed configuration by the moveable sheath;
        after the loading step, advancing the delivery and implantation system transluminally over a guide wire within the patient to position the replacement heart valve device for deployment within the patient at the location of the native heart valve;
        after the advancing step, partially deploying a distal portion of the replacement heart valve device within the patient by pushing out the pusher member from the moveable sheath to expose the distal portion of the replacement heart valve device;
            after the partially deploying step, restraining the replacement heart valve device so that it does not pop out and is held for controlled release, with a potential that the replacement heart valve device can be recovered if there is a problem with positioning; and
        after the restraining step, recovering the distal portion of the replacement heart valve device within the moveable sheath that was exposed in order to address a problem with the position of the replacement heart valve device within the patient.

    (wherein the language set forth in the opinion in boldface identifies the limitation at issue in this case).  A device used in practicing the claimed method is set forth in the opinion using this schematic drawing:

    Image 1
    The opinion recites how the replacement valve is positioned in the practice of the claimed methods:

    A flexible, hollow catheter (400) carrying the stent (100)—to which the replacement heart valve (200), not shown, is sutured—is inserted into a blood vessel of the patient, e.g., the femoral artery, and advanced through the circulatory system to the location of the valve that is to be replaced.  The catheter (400) includes a pusher member (420), and, in some embodiments, a move-able sheath (460) that covers the stent (100) and valve (shown pulled down for display purposes).

    Once the catheter is in what seems the desired position, the pusher member (420) pushes the stent (100) and valve (200) towards the distal end of the catheter (410) such that the stent (100) only partially expands.  At that stage, if the positioning seems incorrect, the valve can be "recaptured" (i.e., recovered and returned to its original position within the catheter, with the stent resqueezed) and redeployed once the catheter's overall location is adjusted.  If no recapture is necessary, the catheter (400) is retracted slightly, and the pusher member (420) fully pushes out the stent (100) and valve from the catheter (400).  In embodiments with a moveable sheath (460), the stent (100) and valve are released by pulling the moveable sheath towards the proximal end (440) of the catheter (400), "allowing the self-expending stent to achieve its full expansion."

    (citations to the record omitted).

    Medtronic argued at trial that their accused infringing device, having this structure:

    Image 2
    was operated by retracting the sheath (the second, abandoned embodiment) rather than pushing the valve out from the sheath (the embodiment to which the granted claims were directed.  In practice, a deployment knob outside the body "controls the position of the moveable sheath relative to the replacement heart valve and stent[, whereby] rotating the deployment knob in one direction retracts the moveable sheath and uncovers (i.e., partially or fully deploys) the replacement heart valve and stent, while rotating in the other direction re-covers (i.e., recaptures) the replacement heart valve and stent."

    After a special master recommended that the District Court adopt Medtronic's construction of the term "pushing out the pusher member from the moveable sheath" to mean "pressing against the pusher member with a force that moves the pusher member out of the moveable sheath," the parties each moved for summary judgment.  Medtronic's motion was predicated on Colibri's cancellation of then-pending claim 39 during prosecution raising PHE to defeat Colibri's assertion of inducing infringement under the doctrine of equivalents:

    A method of controlled release of a percutaneous replacement heart valve in a patient where a bio-prosthetic heart valve is indicated, comprising:
        providing a replacement heart valve device and a delivery and implantation system;
        the replacement heart valve device including:
            a stent member that is collapsible, expand-able and configured for percutaneous delivery; and
            a valve attached to the stent member, the valve including two to four individual leaflets;
        the delivery and implantation system including:
            a pusher member and a moveable sheath, wherein the pusher member includes a lumen for receiving a guide wire, wherein the moveable sheath includes a lumen configured for receiving the pusher member, and wherein the replacement heart valve device is collapsed onto the pusher member to reside in a collapsed configuration on the pusher member and is restrained in a collapsed configuration by the moveable sheath;
        after the providing step, advancing the delivery and implantation system over the guide wire within the patient to position the replacement heart valve device for deployment within the patient;
        after the advancing step, partially deploying the replacement heart valve device within the patient by retracting the moveable sheath to expose a portion of the replacement heart valve device; and
            after the partially deploying step, recovering the portion of the replacement heart valve device within the moveable sheath that was exposed in or-der to address a problem with the position of the replacement heart valve device within the patient.

    (emphasis on language at issue in the case).

    Relying again on a special master's decision that claim 39 and asserted claim 1 were "separate and distinct," the District Court denied Medtronic's summary judgment motion and the case went to trial.  A jury held in favor of Colibri based on an application of the doctrine of equivalents and awarded $106 million in damages.  After Medtronic unsuccessfully filed motions for judgment as a matter of law (JMOL), this appeal followed.

    The Federal Circuit reversed, in an opinion by Judge Taranto joined by Judges Hughes and Stoll.  The panel agreed with Medtronic that the jury's verdict was precluded by the doctrine of prosecution history estoppel due to Calibri cancelling the "retraction" method of correcting improper positioning of the valve.  The panel focused on Medtronic's appeal of the District Court's denial of JMOL for non-infringement based on PHE, which carried the burden of establishing that "the evidence, construed in the light most favorable to the nonmoving party, permits only one reasonable conclusion, and that conclusion is contrary to the jury's verdict,"  citing TVIIM, LLC v. McAfee, Inc., 851 F.3d 1356, 1362 (Fed. Cir. 2017) (quoting Harper v. City of Los Angeles, 533 F.3d 1010, 1021 (9th Cir. 2008)).  On the other hand, PHE is a question of law for which the Court made its determinations de novo (this difference in standard being relevant if not dispositive to the Court's decision).  The panel's decision was based entirely on the PHE question, wherein the Court found that "a combination of applying a pushing force to the pusher member while retracting the moveable sheath (what Medtronic's device does) is equivalent to, i.e., not substantially different from, 'pressing against the pusher member with a force that moves the pusher member outward from the moveable sheath'" (what claim 1 requires).

    The District Court erred in two aspects of the PHE question, according to the opinion, the first regarding that the equivalent advanced by Colibri was "distinct and separate" from cancelled claim 39 and second, that canceling claim 39 was not a narrowing amendment.  Regarding the first error, the panel disputed the distinction relied upon by the District Court that "claim 39 did not require pushing the inner member—only retracting the moveable sheath—whereas Medtronic's . . . devices require both pushing and retracting."  The Court recognized that this contention was contrary to the "simple physics" asserted by Colibri regarding its theory of equivalence ("requiring that opposing forces (i.e., pushing and retracting) be applied to deploy the valve and stent from the moveable sheath") (also stated as "pushing necessarily accompanies retracting").  Colibri's DOE argument (related to "pure retraction") is inconsistent with this simple physics, because "pure retraction of the moveable sheath would result in retraction of the stent and valve as well—the only way to deploy (i.e., separate) the stent and valve from the moveable sheath is to simultaneously exert a pushing force on the inner member holding the stent and valve" which is recited in cancelled claim 39.

    Regarding Medtronic's second argument, the Court held that cancelling claim 39 was a narrowing amendment that PHE barred from assertion under the DOE.  The scope of PHE's effect on assertion under the doctrine is such that "the required narrowing is not a purely formal matter of altering a single claim's terms; it can exist, and we conclude here does exist, as a substantive matter based on cancelling a closely related claim involving such intertwined terminology that cancelling one claim necessarily communicated that the scope of the other claim had narrowed."  The panel held that the District Court's error was to "rely on [the] formalities" regarding separate independent claims: granted claim 1 was not amended although claim 39 was cancelled.  The "close relationship" between the inventions so claimed would have been recognized by the skilled artisan to be "closely related as a substantive matter," thereby "giving up one communicates a narrowing message about the one retained," citing the principles of the relationship between the DOE and PHE set forth in Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., 535 U.S. 722, 733 (2002), rejection of a formalistic approach in Honeywell International Inc. v. Hamilton Sundstrand Corp., 370 F.3d 1131, 1141–44 (Fed. Cir. 2004) (en banc), and consistency to the Festo approach applied in subsequent cases, citing Glaxo Wellcome, Inc. v. Impax Laboratories, Inc., 356 F.3d 1348, 1356 (Fed. Cir. 2004).  Accordingly, the Court "reject[ed] Colibri's contention that claim 1 itself had to be amended for prosecution history estoppel to apply" due to "[t]he close substantive relationship between the cancelled and retained claims."

    The doctrine of equivalents was reinvigorated by the Supreme Court in Warner-Jenkinson v. Hilton Davis Chemical after having been neglected by the Federal Circuit as being contrary to its mandate to harmonize U.S. patent law, due to the inherent uncertainties that can arise (or be perceived to arise) by its application.  After Festo there was another lull in Federal Circuit cases on the doctrine, although there has been a recent uptick (see Ajinomoto Co. v. International Trade Commission, Jennewein Biotechnologie GmbH v. International Trade Commission and Galderma Laboratories, L.P. v. Amneal Pharmaceuticals LLC)).  This case, while denying a finding of DOE infringement nevertheless illustrates the continued vitality of the "push me-pull you" nature of the relationship between DOE infringement and the counterweight provide by PHE.

    Colibri Heart Valve LLC v. Medtronic Corevalve, LLC (Fed. Cir. 2025)
    Panel: Circuit Judges Taranto, Hughes, and Stoll
    Opinion by Circuit Judge Taranto

  • Shockwave Medical, Inc. v. Cardiovascular Systems, Inc. (Fed. Cir. 2025)

    By Kevin E. Noonan —

    Federal Circuit SealReceived wisdom is that inter partes review proceedings are limited to prior art as defined by patents and printed publications.  But in recently decided Shockwave Medical, Inc. v. Cardiovascular Systems, Inc., another prior art species, applicant-admitted prior art (AAPA), played a strong role in helping the Petitioner satisfy the burden of showing that the challenged claims were obvious.

    The case arose as an inter partes review challenging all claims of U.S. Patent No. 8,956,371, directed to devices for treating atherosclerosis through intravascular lithotripsy ("IVL") (thus giving the Court the opportunity to explain several polysyllabic medical terms).  Atherosclerosis (being the easier or at least more commonly known term) the opinion reminds is a common condition characterized by the buildup of fatty deposits in blood vessels that calcifies with age and restricts blood flow.  Conventional treatment includes balloon angioplasty wherein atherosclerotic plaques are compressed onto blood vessel walls and blood flow thereby increased.  Specifically the opinion notes that "[a] typical balloon catheter is the over-the-wire balloon catheter, which consists of a hollow carrier (called a lumen), which is inserted over a wire to guide the balloon catheter to the correct position."  Lithotripsy is a technique usually used to treat kidney stones by using high intensity sonic waves to break up the stones so they can pass through the ureters and urethra.  This technique uses plasma produced in two ways:  one using an electrical discharge (termed "electrohydraulic lithotripsy") and the other by laser.  The invention uses electrohydraulic lithotripsy to break up calcified atherosclerotic plaque to treat atherosclerosis.  The claimed device uses a conventional over-the-wire angioplasty balloon catheter and adds electrodes and a pulse generator.

    Claim 1 is set forth as being exemplary:

    1.  An angioplasty catheter comprising:
        an elongated carrier sized to fit within a blood vessel,
        said carrier having a guide wire lumen extending there through;
        an angioplasty balloon located near a distal end of the carrier with a distal end of the balloon being sealed to the carrier near the distal end of the carrier and with a proximal end of the balloon defining an annular channel arranged to receive a fluid therein that inflates the balloon; and
        an arc generator including a pair of electrodes,
        said electrodes being positioned within and in non-touching relation to the balloon,
        said arc generator generating a high voltage pulse sufficient to create a plasma arc between the electrodes resulting in a mechanical shock wave within the balloon that is conducted through the fluid and through the balloon and wherein the balloon is arranged to remain intact during the formation of the shockwave.

    Dependent Claim 2 recites that the pair of electrodes includes a pair of metallic electrodes, and dependent claim 5 recites:

    5.  The catheter of claim 2, wherein the pair of electrodes is disposed adjacent to and outside of the guide wire lumen.

    In its IPR petition, Cardiovascular Systems (CSI) asserted as its primary reference supporting its obviousness allegations European Patent Application Publication No. EP 0571306 A1 to Levy, which discloses using laser-generated pulses to break up atherosclerotic plaque in blood vessels.  CSI's argument was that it would have been obvious to modify "well-known" angiogenic catheters to produce plasma pulses as disclosed by Levy, basing their "well-known" argument on it being "applicant admitted prior art (AAPA)" by Shockwave (such as "typical prior art over-the-wire angioplasty balloon catheters[s] . . . [that] are usually non-compliant with a fixed maximum dimension when expanded with a fluid such as saline").  The Patent Trial and Appeal Board issued its Final Written Decision that claims 1-4 and 6-17 were obvious but failed to invalidate claim 5 on obviousness grounds.  In its Decision, the Board held that AAPA qualified to support CSI's obviousness assertions.  Less than one month thereafter the Patent and Trademark Office ("PTO") issued a binding guidance that AAPA was not prior art under Section 311(b) of the statute, and the Board reconsidered, arriving at the same legal conclusion of obviousness but characterizing AAPA as merely being "evidence of the background knowledge in the art."  This appeal followed.

    The Federal Circuit affirmed Shockwave's appeal and reversed the Board's decision on claim 5 in Cardiovascular System's cross-appeal, in an opinion by Judge Dyk joined by Judges Lourie and Cunningham.  After dismissing (in a footnote) CSI's contention that Shockwave's appeal of the Board's decision to consider AAPA to be applicable to the obviousness question under Section 311(b) was precluded by Section 314(d), the panel on the merits rejected Shockwave's contention that considering AAPA was error.  According to the Federal Circuit, while Section 311(b) specifies patents or printed publications as the source of prior art used to render a decision regarding a petitioner's validity challenge, "it does not follow that we ignore the skilled artisan's knowledge when determining whether it would have been obvious to modify the prior art," citing Koninklijke Philips N.V. v. Google LLC, 948 F.3d 1330, 1337 (Fed. Cir. 2020).  The reason:  obviousness "requires an assessment of the . . . 'background knowledge possessed by a person having ordinary skill in the art'" under Dow Jones & Co. v. Ablaise Ltd., 606 F.3d 1338, 1349 (Fed. Cir. 2010) (quoting KSR Int'l Co. v. Teleflex, Inc., 550 U.S. 398, 401 (2007)).  The Court in Qualcomm Incorporated v. Apple Inc., 24 F.4th 1367 (Fed. Cir. 2022) ("Qualcomm I"), and Qualcomm Incorporated v. Apple Inc., 134 F.4th 1355 (Fed. Cir. 2025) ("Qualcomm II") had determined that AAPA was properly considered in making obviousness determinations.  These cases held that while AAPA can be used to support the substantive question of invalidity it cannot be used as the basis for the IPR petition (but it can be used in combination with permissible patents or printed publications).

    In this case, CSI did not use AAPA as the express basis for its obviousness challenge, but "only to show, as the '371 patent itself acknowledged, that the over-the-wire angioplasty balloon catheter was well known in the prior art and that this general background knowledge satisfied the '371 patent's claim limitations relating to an over-the-wire configuration."

    The Court also rejected Shockwave's argument that the Board used the term "basis" in referring to the asserted AAPA, on the grounds that while their precedent held Petitioner to a standard where AAPA was not used as the basis for an IPR petition, this restriction did not apply to the Board's characterizations regarding AAPA.

    Shockwave also argued unsuccessfully regarding claim construction, wherein the Board rejected their interpretation of "angioplasty balloon" to mean "a balloon that displaces the plaque into the vessel wall to expand the lumen of the vessel" in favor of CSI's construction of "an inflatable sac that is configured to be inserted into a blood vessel for use in a medical procedure to widen narrowed or obstructed blood vessels."  The significance of this choice (according to Shockwave) is that it misconstrued the meaning of the term "angioplasty."  The panel rejected Shockwave's challenge on this issue because "[n]othing in the language of the claims or specification supports requiring that an angioplasty balloon press plaque into the vessel wall" (indeed the specification asserted that "pressing" or "fitting snugly" into the vessel wall" was not "a requirement").  Nor was the panel convinced that the prosecution history supported Shockwave's construction.

    Shockwave's last challenge to the Board's decision was directed towards three of the Board's fact findings.  First, that the skilled artisan would have been motivated to adapt Levy's shockwave system to an over-the-wire balloon catheter.  Second, that Levy discloses producing shockwaves in the first place.  And third, that secondary considerations did not rebut CSI's prima facie obviousness showing.

    The panel held that substantial evidence supported all three of the Board's factual determinations.  First, the Court found that contrary to Shockwave's argument the Board asserted two reasons why an ordinarily skilled artisan would have combined conventional balloon angioplasty with Levy's shockwave technology:  "(1) "to assist a physician to navigate the catheter to reach the area for treatment" and (2) "to increase the types of treatments Levy could perform."  This evidence was supported (according to the opinion) by CSI's expert witness testimony.  Nor did the panel credit Shockwave's contention that there was insufficient evidence that Levy's technology could produce shockwaves in blood vessels (to the extent that the Levy EP reference incorporated an earlier Levy patent by reference, relating to cleaning tooth canals with laser radiation pulses that disclosed "this same technique 'can also be employed in the medical field for cleaning vessels, such as blood vessels'") (there being additional undiscussed prior art references supporting the use of shockwaves as disclosed by Levy).  Regarding evidence of secondary considerations, the Board rejected as insufficiently persuasive Shockwave's expert's testimony supporting a presumption of a nexus related to non-obviousness (the totality of what the opinion calls Shockwave's "purported objective indicia" was "largely weak" being based on "potential efficacy" or "potential commercial success").

    Turning to CSI's cross-appeal on the Board's determination that claim 5 had not been shown to be obvious, the opinion first rejected Shockwave's contentions that CSI lacked standing to appeal.  Recognizing that a party needs to establish Article III standing to appeal (but not to bring an IPR, under Incyte Corp. v. Sun Pharm. Indus., Inc., 136 F.4th 1096, 1099 (Fed. Cir. 2025), the panel turned to CSI's assertions (required under Gen. Elec. Co. v. Raytheon Techs. Corp., 983 F.3d 1334, 1341 (Fed. Cir. 2020)) that in the absence of current infringing activity it must have "concrete plans for future activity that creates a substantial risk of future infringement."  CSI relied on its development of an IVL device and Shockwave's CEO's statement that the company intended to "aggressively assert" claim 5 of the '371 patent to be sufficient to establish Article III standing.

    Regarding the merits, CSI argued that the Board failed to consider the prior art as a whole, and the Federal Circuit agreed. Specifically, CSI asserted a Japanese patent application to Uchiyama and expert testimony concerning the combination to support CSI's obviousness contentions.  The panel found that the Board erred in not combining the Uchiyama disclosure with Levy's modification of a conventional over-the-wire catheter balloon.  As a result, the Board "improperly discount[ed] CSI's argument in its petition that modifying Uchiyama to place the electrodes outside the lumen would have been a routine design choice" according to the opinion.  This was contrary to the rubrics in KSR v. Teleflex that "[w]hen there is a design need or market pressure to solve a problem and there are a finite number of identified, predictable solutions, a person of ordinary skill has good reason to pursue the known options within his or her technical grasp" and accordingly was error by the Board.  In view of the factual situation that Shockwave had not adduced evidence on the record, contrary to the Board's erroneous nonobvious determination the panel reversed the decision rather than vacating and remanding.

    This result immediately suggests that, while patent applicants are required under the duty of candor (37 C.F.R. § 1.56), the key word in the dispositive phrase in the court's opinion is admitted prior art.  There is little admission involved in citing a patent or printed publication that antedates the earlier priority date asserted (or accorded) to an application (other than any dispute arising from whether the reference was publicly available).  But there are many opportunities to characterize (to the applicant's detriment) the status of knowledge in the prior art; for example, when facing a Section 112(a) challenge on enablement or written description grounds.  Here Shockwave's specification provided the needed AAPA.  Patent law has often been characterized as being replete with "traps for the unwary" and the outcome of this case reinforces the need for prudence in how prior knowledge is considered (or admitted) by applicants before they become patentees.

    Shockwave Medical, Inc. v. Cardiovascular Systems, Inc. (Fed. Cir. 2025)
    Panel: Circuit Judges Lourie, Dyk, and Cunningham
    Opinion by Circuit Judge Dyk

  • The Preemption Doctrine: A Necessary Course Correction After Recentive v. Fox

        By Manav Das —

    Federal Circuit SealThe landscape of patent law for artificial intelligence (AI) and machine learning (ML) innovations has become fraught with uncertainty.  The U.S. Court of Appeals for the Federal Circuit's precedential opinion in Recentive Analytics, Inc. v. Fox Corp.[1], issued on April 18, 2025, represents a watershed moment for the starkness with which it exposes the fundamental inadequacies of the current subject matter eligibility approach under 35 U.S.C. § 101.  In its first opinion addressing the patent eligibility of ML technologies, the Court affirmed the invalidation of four patents, establishing a formidable and flawed precedent that threatens to stifle innovation in one of the most critical technological sectors of our time.  The decision, while consistent with a problematic line of jurisprudence stemming from Alice Corp. v. CLS Bank International[2], serves as a quintessential example of how the two-step Alice/Mayo framework is ill-equipped to evaluate the true inventive character of ML inventions.  By mischaracterizing applied ML as "generic" and dismissing the very process of training as non-inventive, the Court has constructed a legal framework that is profoundly disconnected from technological reality, creating a potentially insurmountable barrier for patenting a vast and vital category of AI innovations.  A meticulous deconstruction of the Recentive decision reveals not just a flawed outcome, but a flawed legal test as well that is in urgent need of reform.

    I.    The Factual and Procedural Background of Recentive

    The case centered on four patents held by Recentive Analytics, which fell into two families:  the "Machine Learning Training" patents (U.S. Patent Nos. 11,386,367 and 11,537,960) and the "Network Map" patents (U.S. Patent Nos. 10,911,811 and 10,958,957).  The patents claimed methods and systems for using ML to optimize the scheduling of live television events and to generate dynamic network maps for broadcasters; tasks that, as the Court noted, were previously performed manually by humans.  Recentive sued Fox Corp. and its affiliates for infringement, and Fox responded with a motion to dismiss, arguing that the patents were directed to ineligible subject matter under § 101.

    The case highlights by their absence some drafting "best practices" that were not followed and that eventually weighed against the patentee.  For example, the drafters included language stating that the invention could use "any suitable machine learning technique,"[3] providing a laundry list of conventional models such as neural networks, decision trees, support vector machines, and regressions.  This broad, non-specific language provided the Court with textual basis to characterize the claimed technology as "generic" and "conventional."

    Additionally, during litigation, the patentee admitted that it was "not claiming machine learning itself" and that the patents did not claim a specific method for "improving the mathematical algorithm or making machine learning better."  Recentive also acknowledged that "the concept of preparing network maps[] [had] existed for a long time," and that prior to computers, "networks were preparing these network maps with human beings."[4]  These admissions effectively allowed the Court to conclude that the patents did nothing more than apply existing, off-the-shelf technology to a new field.  Unfortunately, the perceived weaknesses related to the Recentive case have led to the creation of a broad, damaging precedent for the entire AI industry, a precedent that future innovators must now navigate.

    A.    The Alice Step One Analysis: An Overly Broad Characterization of the "Abstract Idea"

    Applying the first step of the Alice/Mayo framework, the Federal Circuit had to determine whether the claims were "directed to" a patent-ineligible concept, such as an abstract idea.  The Court affirmed the District Court's finding that they were, characterizing the patents as being directed to the abstract ideas of "producing event schedules and network maps using known generic mathematical techniques".

    The core of the Court's reasoning culminated in an overbroad holding:  "patents that do no more than claim the application of generic machine learning to new data environments, without disclosing improvements to the machine learning models to be applied, are patent ineligible under § 101."[5]  This holding effectively invalidates a common and crucial form of innovation in the AI field:  the novel application of existing ML tools to solve problems in new domains.

    The Court explicitly rejected Recentive's argument that applying ML to a new field of use — in this case, television broadcasting and event scheduling — could confer patent eligibility.  Citing established precedent, the Court reiterated that "[a]n abstract idea does not become nonabstract by limiting the invention to a particular field of use or technological environment."[6]  Similarly, the Court was unpersuaded by the argument that the invention was patentable because it applied existing technology to a novel database or data environment.[7]  This line of reasoning is particularly problematic for AI, where the curation and application of novel datasets is often a key part of the inventive process.

    Furthermore, the Court dismissed Recentive's claims that its inventions were patent-eligible by the fact that "(using existing machine learning technology) they perform a task previously undertaken by humans with greater speed and efficiency than could previously be achieved."[8]  The Federal Circuit has consistently held that improvements in speed or efficiency resulting from the use of a generic computer do not, by themselves, create eligibility unless they are based on improved computer techniques.

    By equating a sophisticated, trained ML model with a "generic computer," the Court overlooked the transformative technological leap that such automation represents.  This line of reasoning has been problematic even prior to Recentive.  Improvements in speed or efficiency resulting from the use of a generic computer or limiting an abstract idea to a particular technological environment are issues that are best handled using the evidentiary approach under Sections 102 and 103.  Indeed, some of these issues should be analyzed from a viewpoint of a person of ordinary skill at the time of the invention.  However, by bringing such issues under the ambit of Section 101, courts have created a legal framework that is confusing, arbitrary, unreliable, and utterly subjective.  This overly broad characterization at Alice Step One set the stage for the claims' inevitable failure at Step Two.

    B.    The Alice Step Two Analysis: The Search for a Non-Existent "Inventive Concept"

    Having concluded that the claims were directed to an abstract idea, the Court proceeded to the second step of the Alice test, which asks whether the claims include an "inventive concept" sufficient to "transform" the abstract idea into a patent-eligible application. The Court searched for something "significantly more" than the abstract idea itself but concluded that it could "perceive nothing in the claims" that met this standard.[9]

    Recentive argued that the inventive concept was the use of "machine learning to dynamically generate optimized maps and schedules based on real-time data and update them based on changing conditions."[10]  The Court dismissed this argument, stating that this was "no more than claiming the abstract idea [of generating event schedules and network maps] itself"[11] and failed to identify any transformative element.

    The Court's most consequential finding at Step Two was its characterization of core ML processes as non-inventive.  It stated that "requirements that the machine learning model be 'iteratively trained' or dynamically adjusted in the Machine Learning Training patents do not represent a technological improvement."[12]  This was despite Recentive's argument that its application of machine learning is not generic because "Recentive worked out how to make the algorithms function dynamically, so the maps and schedules are automatically customizable and updated with real-time data,"[13] . . . and because "Recentive's methods unearth 'useful patterns' that had previously been buried in the data, unrecognizable to humans."[14]  This alone should have been sufficient for a finding of subject matter eligibility.

    The Court's analysis reveals a profound judicial misunderstanding of where innovation in applied ML frequently resides.  The specific process of iterative training on a dataset to solve a particular problem is often the very heart of the invention.  By deeming this process inherent and routine, the Court effectively precludes from patent protection a major avenue of AI innovation.  Moreover, when a "generic" ML model is trained to perform a specific task on a specific training dataset, this clearly transforms the "generic" ML model into a special purpose ML model, which should be subject matter eligible.  Whether such a special purpose ML model and/or use thereof is patent-eligible is properly a consideration under Sections 102, 103, and 112.

    Throughout its analysis, the Court repeatedly returned to the theme of the "missing 'how.'"  It faulted the patents because "neither the claims nor the specifications describe how such an improvement was accomplished"[15] and failed to "delineate steps through which the machine learning technology achieves an improvement."[16]  This demand for a detailed, step-by-step recitation of "how" a technological improvement is achieved is fundamentally misaligned with the nature of ML.  In many cases, the improvement is an emergent property of the training process; the model learns to recognize patterns that may be too complex for a human to explicitly define or describe or even know.  To demand a precise explanation of "how" a neural network achieves its optimized state is to demand an explanation of the unexplainable, setting a standard that is not just high, but often technologically impossible.  This judicial skepticism toward emergent properties and learning-based systems indicates that the Alice/Mayo framework is not merely being applied erroneously; it is being applied in a way that is structurally biased against the very nature of modern AI innovation.

    II.    The "Generic" Model Fallacy: A Fundamental Disconnect Between Patent Law and ML Reality

    The Recentive decision rests upon a flawed premise:  that the patents claimed the mere application of a "generic" machine learning model.  This characterization, while convenient for the Court's legal analysis, is a legal fiction that willfully ignores the technical realities of how machine learning models are developed, trained, and deployed.  It creates a false dichotomy that serves to invalidate legitimate technological advancements and reveals a deep, structural disconnect between § 101 jurisprudence and the actual practice of AI innovation.  Challenging this "generic model" fallacy is essential to understanding why the current patent eligibility test is failing.

    A.    General-Purpose vs. Special-Purpose AI: A Critical Distinction

    To understand the Court's error, one must first grasp the critical technical distinction between general-purpose and special-purpose AI models.  Foundation models, also referred to as general-purpose AI (GPAI), are large models like OpenAI's ChatGPT[17], Meta's LLaMA[18], Google's Gemini[19], image generation models such as OpenAI's DALL-E[20], and so forth which are pre-trained on vast, diverse datasets, and often using unsupervised or self-supervised learning.  These models are the "general" tools of the AI world. They are not typically designed for any single task but possess a broad range of capabilities, such as text summarization, language translation, and image generation.  They are, in essence, powerful but unspecialized starting points.  Typically, prompts are used to discover the emergent utilities of such models.  Such models are also extremely expensive and cannot be developed without vast investments of time, money, and specialized personnel.[21]

    In contrast, specialized models, also referred to as narrow AI, are AI systems that have been designed, trained, or fine-tuned to perform a specific task or operate within a specific domain with high efficiency and accuracy.  A model designed to improve diagnosis and drug discovery in healthcare, enhance risk management and fraud detection in finance, perform predictive maintenance and production optimization in manufacturing, or, as in Recentive's case, optimize television schedules, is a specialized model.  These models often possess more streamlined architectures and are more cost-effective for their narrow purpose, but they require extensive, carefully curated, domain-specific training data to achieve their specialized function.  A primary and ubiquitous method for creating a specialized model is to take a general-purpose architecture (or even a pre-trained foundation model) and train or fine-tune it on a specific dataset to solve a specific problem.

    B.    The Act of Training as an Act of Invention: Transforming a General Tool into a Specific Machine

    The central error in the Recentive court's analysis was its failure to recognize this distinction.  The Court focused on the starting point of the invention — a generic class of algorithms like "neural networks" or "decision trees" listed in the specification — rather than the end product of the invention:  a fully trained, specialized model capable of performing a specific, useful function it could not perform before training.

    The act of training a ML model itself is an act of invention that should be subject matter eligible.  The patentability of this act of invention is a separate consideration.  The process of collecting and curating a specific dataset (e.g., historical broadcast schedules, event parameters, target features, venue locations, and ticket sales, as described in the Recentive patents) and then applying computational resources to train a model on that data is what transforms the general algorithmic tool into a special-purpose machine.

    Once trained, the model is no longer "generic."  It is a new technological artifact.  Its internal configuration, such as the millions or billions of weights and biases within its neural network, has been fundamentally altered and optimized to embody the patterns and relationships learned from the training data.  This newly configured model is a specific machine, designed and built for a particular purpose.  The Court's dismissal of this transformation as a mere "application" of an abstract idea is akin to saying that programming a general-purpose computer to perform a new and useful task is not a technological improvement because the underlying computer hardware is "generic."

    This reveals a fundamental contradiction at the heart of the court's reasoning.  On one hand, the Court dismisses the process of "iterative training" as an inherent, non-inventive aspect of machine learning.  On the other hand, it demands that the patentee show a specific improvement to the machine learning model itself.  For the vast majority of applied AI inventions, the specific improvement is the direct result of that very training process.  The trained model is the improved model.  By treating the process as inherent and the resulting application as abstract, the Court creates an inescapable trap that leaves no conceptual space for patentability.  This approach, which dissects the invention into its constituent parts ("known training technique" and "abstract application domain") and finds no eligible subject matter in the pieces, fails to recognize the inventive character of the integrated whole.  This is a well-recognized flaw in § 101 analysis, but one that is particularly damaging in the context of AI.

    C.    The Legal Consequences of the "Generic" Fallacy

    By enshrining the "generic model" fallacy into precedential law, the Recentive decision has profound and damaging consequences.  It effectively declares that one of the most common and powerful forms of innovation in the modern technology industry — the practical application and specialization of ML models to solve real-world problems — is presumptively patent-ineligible.

    This essentially creates a paradox:  the more fundamental and broadly applicable a foundational ML technique (like a neural network architecture) becomes, the less likely its specific, value-creating applications are to be deemed patentable.  This is contrary to the constitutional purpose of the patent system, which is to incentivize the reduction of abstract principles to practice. The decision signals that the current § 101 framework is inherently biased toward inventions that can be easily described as a novel physical mechanism or a discrete, new mathematical algorithm.  This framework is structurally incapable of properly valuing inventions where the innovation is embodied in the complex configuration of a system (like the weights of a neural network) that is achieved through a process of data-driven learning.

    The inevitable result of this legal uncertainty and subjectivity is that innovators will be pushed away from the patent system and toward trade secret protection.  While trade secrecy can protect certain AI innovations, such as model weights or proprietary training data, it does so at a great cost to society.  The patent system's core bargain is one of disclosure in exchange for a limited monopoly.  By making patents for applied AI exceedingly difficult to obtain and enforce, the law discourages this disclosure, slowing the overall pace of innovation and preventing the public dissemination of knowledge that is crucial for building the next generation of technology.  At the same time, foreign nations may allow such innovations to be patentable, thereby creating a competitive barrier to American commerce and economic leadership.

    III.    Restoring the Cornerstone of § 101: Preemption as a Superior Analytical Framework

    The labyrinthine complexity of the Alice/Mayo framework, with its ambiguous steps and technologically unsound assumptions, is not an accidental feature; it is a symptom of a deeper doctrinal malady.  The test has become unmoored from its conceptual anchor.  The current two-step inquiry should be set aside in favor of a direct analysis of preemption.  This approach, which is more faithful to the Supreme Court's own foundational jurisprudence, offers a clearer, more consistent, and technologically neutral standard for judging the patent eligibility of machine learning and other computer-implemented inventions.  It is the necessary course correction to rescue § 101 from its current state of incoherence.

    A.    The Doctrinal Foundation: Preemption as the "Ultimate Touchstone" of § 101

    A historical review of the judicial exceptions to patent eligibility — laws of nature, natural phenomena, and abstract ideas — reveals a single, unifying concern:  preemption.  As noted in Alice, the Supreme Court has "repeatedly emphasized this . . . concern that patent law not inhibit further discovery by improperly tying up the future use of these building blocks of human ingenuity."[22]  The fear is that granting a patent on a basic tool of science or technology, such as a mathematical formula or a fundamental economic practice, would "tend to impede innovation more than it would tend to promote it."[23]

    This concern animates the Court's landmark § 101 decisions.  In Gottschalk v. Benson[24], the Court invalidated a claim for converting numerical information because it would "wholly pre-empt the mathematical formula" and effectively be a patent on the algorithm itself.  Conversely, in Diamond v. Diehr[25], the Court found claims using the Arrhenius equation to be eligible because they were tied to a specific industrial process for curing rubber and did not preempt all uses of the equation.  More recently, in Bilski v. Kappos[26], the Court cautioned against claims that would "pre-empt the use of [an] approach in all fields," and in Alice itself, the Court unequivocally stated that "the concern that drives this exclusionary principle is one of pre-emption".  Preemption is not merely a peripheral consideration; it is the "ultimate touchstone" and the very reason the judicial exceptions exist.

    B.    The Jurisprudential Drift: How the Federal Circuit Unmoored the Test from Preemption

    Despite the Supreme Court's clear guidance, the Federal Circuit's application of the two-step Alice/Mayo framework has evolved into a rigid, formalistic exercise that frequently sidelines, and at times openly dismisses, the core preemption inquiry.  The test has become an end in itself, rather than a means to address the underlying policy concern.

    This jurisprudential drift is most evident in the Federal Circuit's explicit holdings on the matter.  In cases like Ariosa Diagnostics, Inc. v. Sequenom, Inc.[27], the Court has declared that "the absence of complete preemption does not demonstrate patent eligibility."[28]  This statement represents a stunning departure from the doctrine's foundational logic.  If the sole purpose of the judicial exception is to prevent the harm of preemption, then the demonstrated absence of that harm should be dispositive of eligibility.  To hold otherwise is to allow the exception to "swallow all of patent law."[29]

    The "abstract idea" category, in particular, has been expanded far beyond its intended role as a proxy for preemptive claims.  It has become a mechanism for courts to invalidate claims that are specific, applied, and non-preemptive simply because their subject matter can be generalized to a high level of abstraction, such as a "fundamental economic practice" or a "mental process."  This has led to the erratic and unpredictable results that now plague § 101 jurisprudence, creating an environment of profound uncertainty for innovators, investors, and the patent system as a whole.

    The internal logic of the two-step framework is itself flawed.  The test allows, and even encourages, a court at Step One to label a claim as being "directed to" an abstract idea even if the claim is narrow and poses no realistic threat of preemption.  This initial characterization, however, is not neutral; it taints the entire subsequent analysis.  At Step Two, the Court is then asked to search for an "inventive concept," but the elements of the claim that were used to label it "abstract" in the first place are effectively discounted.  This makes it nearly impossible for a claim, once branded "abstract," to be saved.  The result is that specific, practical, and non-preemptive inventions are routinely invalidated.  The Supreme Court created the "abstract idea" category as a tool to identify potentially preemptive claims; the Federal Circuit has transformed the tool into the test itself.  By focusing on whether a claim can be described as abstract, rather than whether it is preemptive in its scope, the Court has inverted the analysis and created a doctrine that is inconsistent and untethered from its policy moorings.

    C.    A Better Way Forward: Applying a Preemption-First Analysis

    One remedy for this doctrinal confusion is to return to first principles.  The vague, two-step Alice/Mayo inquiry should be replaced with a more direct and coherent test focused on the only question that matters:  does the claim, as a whole, preempt all practical applications of a law of nature, natural phenomenon, or abstract idea?  If the answer is no, the claim should be deemed patent-eligible under § 101, and the examination should proceed to the substantive requirements of novelty (§ 102), non-obviousness (§ 103), and enablement (§ 112), which are the proper statutory vehicles for assessing the inventive merit of a specific technological implementation.

    Applying this preemption-first analysis to the facts of Recentive demonstrates its superiority.  The claims at issue were directed to a specific application:  using ML to generate optimized television schedules and network maps based on specific types of data, such as historical broadcast information and real-time parameters.

    • Did these claims preempt the abstract idea of scheduling?  No.  Humans and other computer systems remained free to create schedules.
    • Did they preempt all uses of machine learning?  Clearly not.
    • Did they even preempt all uses of machine learning for scheduling?  No.  A competing innovator would remain free to develop a different scheduling system using a different ML model, a different set of training data, different pre- or post-processing techniques, or different feature engineering to achieve a similar result.  The claims did not "wholly pre-empt" a fundamental building block.

    Because the claims under consideration in Recentive posed no danger of disproportionately tying up a basic tool of science or commerce, they should have been found eligible under a proper, preemption-focused § 101 analysis.  Whether Recentive's specific implementation was novel over the prior art or non-obvious to a person of ordinary skill in the art are separate, important questions — but they are questions for §§ 102 and 103, not § 101.  A preemption-centric framework would restore § 101 to its intended role as a "coarse filter" designed to screen out only those claims that truly seek to monopolize a fundamental principle, not those that claim a specific, practical application of one.

    IV.    Conclusion: Realigning Patent Law with Technological Reality

    The Federal Circuit's decision in Recentive is not an anomaly but a predictable outcome of a broken legal framework where a flawed reasoning has been reinforced and amplified.  The ruling, which effectively deems the common practice of applying known machine learning techniques to new domains as patent-ineligible, is built upon the "generic model" fallacy — a fundamental misapprehension of how innovation in artificial intelligence occurs.  By dismissing the transformative act of training as "inherent" and demanding a specific, articulable improvement to the underlying algorithm, the Court has created a standard that is profoundly misaligned with the emergent, data-driven nature of modern technology.

    The ultimate solution lies not in more intricate drafting strategies but in doctrinal reform.  The Alice/Mayo two-step test, having become unmoored from its conceptual foundation, has proven to be an unreliable and technologically unsound instrument.  Its vague standards and internal contradictions have injected a level of uncertainty into patent law that chills investment and discourages the public disclosure that the patent system is meant to foster.

    A clear, direct, and principled analysis based on preemption is the viable path forward.  Restoring preemption as the cornerstone of the § 101 inquiry would provide the clarity, predictability, and technological neutrality that the patent system desperately needs.  It would properly relegate § 101 to its intended role as a coarse filter, shifting the substantive examination of an invention's merit back to the well-established doctrines of novelty, non-obviousness, and enablement.  Such a reform, whether enacted by the judiciary or through legislative action, is essential to realign U.S. patent law with the realities of modern innovation and to ensure that the law continues to fulfill its constitutional mandate to "promote the Progress of Science and useful Arts."

    [1] Recentive Analytics, Inc. v. Fox Corp., No. 23-2437 (Fed. Cir. 2025)

    [2] Alice Corp. Pty. Ltd. v. CLS Bank Int'l, 573 U.S. 208 (2014)

    [3] Recentive Analytics, Inc. v. Fox Corp. at 5

    [4] Id. at 7

    [5] Id. at 18

    [6] Id. at 14 (citing Intell. Ventures I LLC v. Capital One Bank (USA), 792 F.3d 1363, 1366 (Fed. Cir. 2015))

    [7] Id. at 14-15

    [8] Id. at 15

    [9] See, generally, id. at 16

    [10] Id.

    [11] Id. at 17

    [12] Id. at 12

    [13] Appellant's Reply Br. 2,

    [14] Id.

    [15] Id. at 12-13

    [16] Id. at 13

    [17] https://openai.com/chatgpt/overview/

    [18] https://www.llama.com/

    [19] https://ai.google.dev/gemini-api/docs/models

    [20] https://openai.com/index/dall-e/

    [21] https://www.tensorops.ai/post/understanding-the-cost-of-large-language-models-llms

    [22] Alice Corp. v. CLS Bank Int'l, 573 U.S. 208, 214 (2014)

    [23] See, e.g., Mayo Collaborative Services v. Prometheus Labs., Inc., 566 U.S. 66, 71 (2012)

    [24] Gottschalk v. Benson, 409 U.S. 63 (1972)

    [25] Diamond v. Diehr, 450 U.S. 175 (1981)

    [26] Bilski v. Kappos, 561 U.S. 593 (2010)

    [27] Ariosa Diagnostics, Inc. v. Sequenom, Inc., 788 F.3d 1371 (Fed. Cir. 2015)

    [28] Id. at 1379

    [29] Alice Corp. v. CLS Bank Int'l, 573 U.S. 208, 217 (2014)

  • Eye Therapies LLC v. Slayback Pharma, LLC (Fed. Cir. 2025)

    By Kevin E. Noonan —

    Federal Circuit SealPatent law in many respects has its own language and idiosyncratic expressions, and one such respect involves so-called "transitional" words or phrases (discussed in greater depth in the Manual of Patent Examination Procedure § 2111.03).  They are termed "transitional" because they mediate the transition between a claim preamble and the elements of the invention recited therein.  The most common such word is "comprises" or "comprising," which indicates that the claim drafter intends the element to encompass what is expressly recited and anything else (within the limits of what the skilled artisan would understand would be operable; this is not an "everything but the kitchen sink" situation).  On the other hand, the words "consisting of" indicate the exact opposite:  the elements recited following this phrase are limited to just what is recited and nothing more.  In what was considered in simpler days to be especially arcane arts such as chemistry there arose a somewhat looser version of this more restricted terminology, the phrase "consisting essentially of."  This transitional phrase was much more limited than "comprising" but permitted a slightly broader scope than "consisting of"; examples included additional unrecited elements in complicated chemical combinations like shampoos.  Any "loosening" of the strictures of "consisting of" is limited to such elements that do not materially affect the "basic and novel" characteristics of the claimed invention.  See, as examples, In re Herz, 537 F.2d 549, 551-52 (CCPA 1976), and Atlas Powder v. E.I. duPont de Nemours & Co., 750 F.2d 1569 (Fed. Cir. 1984).

    The proper construction of this phrase was at issue in Eye Therapies LLC v. Slayback Pharma, LLC, which arose as an inter partes review of all claims of Patent Owner Eye Therapies' U.S. Patent No. 8,293,742.  This patent claims a method to reduce eye redness using a low-concentration dose of brimonidine, which active ingredient is described in a footnote as being "an alpha-adrenergic receptor agonist, a category of compounds known to cause vasoconstriction."  The footnote goes on to explain that this vasoconstrictive effect counteracts vasodilation, which is the cause of many "clinically undesirable events" such as "surface hemorrhage and hyperemia following Lasik surgery" and "eye redness (conjunctival hyperemia)."

    Claims 1 and 3 are set forth in the opinion as representative:

    1.  A method for reducing eye redness consisting essentially of administering brimonidine to a patient having an ocular condition, wherein brimonidine is present at a concentration between about 0.001% weight by volume and about 0.05% weight by volume.

    3.  A method for reducing eye redness consisting essentially of topically administering to a patient having an ocular condition a composition consisting essentially of brimonidine into ocular tissue, wherein pH of said composition is between about 5.5 and about 6.5, wherein said brimonidine concentration is between about 0.001% and about 0.025% weight by volume and wherein said composition is formulated as an ocular drop.

    (wherein the italicized transitional language was at issue in this appeal).  The opinion sets forth the ex parte prosecution context of the importance of this transitional phrase, wherein the patentee had amended the word "comprising" to "consisting essentially of" in the face of a novelty rejection asserted using prior art disclosing a combination of brimonidine and brinzolamide, and applicant argument that "the revised claims 'do not require the use of any other active ingredients (emphasis added) in addition to brimonidine'" (and wherein the examiner expressly recited this argument in their Notice of Allowance).

    In its Petition, Slayback challenged claims 1-6 of the '742 patent; in the Final Written Decision (FWD), the Patent Trial and Appeal Board found all claims of the patent to be invalid for obviousness.  In its claim construction, the Board expressly rejected Patent Owner's arguments that "consisting essentially of" limited the claim to exclude any other active ingredients (despite both the patent applicant and examiner expressly having relied on this distinction in prosecution of the '742 patent claims to allowance).  The Board's reasoning in the FWD was that to do so would construe the phrase to have the same scope as "consisting of."  Under the Board's construction, "the claimed methods cannot include additional active ingredients that are 'required' to perform the method" (emphasis in FWD).  Nevertheless, the Board considered the addition of other active ingredients that "would not materially affect the basic and novel characteristics of the invention" could be included within the scope of the claim.  Under this construction, the prior art disclosure of the combination of combination of brimonidine and brinzolamide would render the '742 claims obvious.  This appeal followed.

    The Federal Circuit reversed in part and vacated in part the PTAB's decision and remanded, in an opinion by Honorable Mark C. Scarsi, District Judge from U.S. District Court for the Central District of California, sitting by designation, joined by Judges Taranto and Stoll.  The panel opinion came straight to the point:  in view of the prosecution history the Board erred in construing the phrase "consisting essentially of" to encompass methods using active ingredients other than brimonidine.  Because this error permitted the Board to consider the combination prior art formulations as falling within the scope of the claim and thus being obvious, the Court vacated the Board's obviousness determination and remanded.

    The basis for the panel's decision that the Board erred in construing "consisting essentially of" was that this phrase had been "long understood" to "permit inclusion of components not listed in the claim, provided that they do not 'materially affect the basic and novel properties of the invention,'" citing AK Steel Corp. v. Sollac, 344 F.3d 1234, 1239 (Fed. Cir. 2003).  And under Phillips v. AWH Corp., 415 F.3d 1303, 1312–13 (Fed. Cir. 2005) (en banc), a patent applicant "can alter the typical meaning . . . by mak[ing] the intended meaning clear in the specification or disclaim an alternative meaning in the prosecution history," citing Ecolab, Inc. v. FMC Corp., 569 F.3d 1335 (Fed. Cir. 2009).  The panel agreed with Eye Therapies' argument that the prosecution here was an example of the patentee so altering the typical scope of a claim reciting "consisting essentially of" as a transitional phrase.  The opinion sets forth ample quotations from the prosecution history of the '742 patent in support of their decision, from both the applicant and patent examiner.  The opinion relies on Shire Dev., LLC v. Watson Pharms., Inc., 787 F.3d 1359, 1366 (Fed. Cir. 2015), Personalized Media Commc'ns, LLC v. Apple Inc., 952 F.3d 1336, 1339 (Fed. Cir. 2020), and Standard Oil Co. v. Am. Cyanamid Co., 774 F.2d 448, 452 (Fed. Cir. 1985), for the principle that "explanatory remarks" made during prosecution can demonstrate what an applicant "meant" by the amendment.  (Of course the converse is also true, to the extent that improvident or unclear "remarks" can produce a construction not intended or anticipated by an applicant.)

    The panel also considered the "strongest indicators" of patent owner's intention to have a "more-restrictive-than-typical interpretation of the phrase 'consisting essentially of'" to be a comparison with the asserted combination prior art, wherein the Court considered patent owner's representations during prosecution that "Dean teaches away from methods consisting essentially of administering brimonidine (i.e., methods which do not include administering other active agents)" (emphasis in opinion).  Also factoring into the panel's decision here is the use of "i.e.," where use of this abbreviation "indicates an intent to define the claimed 'methods'" to exclude other active ingredients.  The panel also found the intrinsic evidence (the prosecution history) to be incompatible with the Board's claim construction.  Nor was the panel persuaded that the existence of alternative embodiments in the '742 specification, reciting "comprising" were incompatible with the restrictive scope of the altered/amended claim language, citing TIP Sys., LLC v. Phillips & Brooks/Gladwin, Inc., 529 F.3d 1364, 1373 (Fed. Cir. 2008), and Pacing Techs., LLC v. Garmin Int'l, Inc., 778 F.3d 1021, 1026 (Fed. Cir. 2015).

    Petitioner Slayback's argument was that although Patent Owner Eye Therapies had represented to the patent examiner that their claims did not require other active ingredients this was not the same as precluding the use of such ingredients.  The panel rejected Slayback's argument that the circumstances here were analogous to the Court's decision in Aylus Networks, Inc. v. Apple Inc., 856 F.3d 1353 (Fed. Cir. 2017), based inter alia on different factual predicates.  According to the opinion:

    Given the applicant's arguments distinguishing Dean and definitional use of "i.e." to equate its claimed "methods consisting essentially of administering brimonidine" with "methods which do not include administering other active agents," (emphasis added), the appropriate interpretation of the applicant's representation that the claimed methods "do not require" agents other than brimonidine is that its claimed methods preclude the use of such agents.

    On this basis the Court reversed the Board's claim construction.

    The Court's assessment of the Board's obviousness determination was that the Board's claim construction was erroneous and "infected its obviousness analysis."  Evidence for this conclusion was the Board's reliance on other prior art directed to methods using combinations with other active ingredients in support for finding the challenged claims obvious.

    Finally, in explaining the decision to vacate and remand, the opinion states:

    We do not prejudge whether the correct claim construction permits the same factual findings or obviousness conclusion.  We do note, however, that because the Board applied an erroneous claim construction, it had no occasion to consider whether, under the prior art, a person of ordinary skill in the art would have been motivated to employ a method with the properly understood limitation signified by the '742 patent's use of "consisting essentially of."  We conclude that the appropriate course in this case, as in so many others involving a reversal of a Board claim construction, is to vacate the Board's decision and remand the matter, citing Kaken Pharma. Co., Ltd. v. Iancu, 952 F.3d 1346, 1355 (Fed. Cir. 2020).

    Eye Therapies, LLC v. Slayback Pharma, LLC (Fed. Cir. 2025)
    Panel: Circuit Judges Taranto and Stoll and District Judge Scarsi
    Opinion by District Judge Scarsi