This article summarizes a few of the seminal developments in U.S. patent law since the passage of the Patent Act of 1952 (1952 Act). We have selected a “baker’s dozen” of cases that had meaningful impact on important patent law doctrines over the decades.
Our review begins 60 years ago, with the U.S. Supreme Court’s explication of the newly codified “nonobviousness” requirement in Graham v. John Deere Co. of Kansas City.
Codification of Nonobviousness—35 U.S.C. § 103
Graham v. John Deere Co. of Kansas City, 383 U.S. 1 (1966)
Graham involved a set of companion cases in which the Supreme Court was asked to address the proper interpretation of 35 U.S.C. § 103, the “nonobviousness” requirement. This statutory requirement for patentability had been codified for the first time in the 1952 Act, although the concept had been recognized in the case law for more than a century by then. The specific question the Court needed to answer was “what effect the 1952 Act had upon traditional statutory and judicial tests of patentability and what definitive tests are now required.”[1]
After tracking back through the history and purpose of the U.S. Constitution’s intellectual property clause[2] and Thomas Jefferson’s skepticism of federal monopolies, the Court determined that the “general condition of patentability” articulated in the pre-Civil War era case Hotchkiss v. Greenwood “laid the cornerstone of the judicial evolution suggested by Jefferson and left to the courts by Congress.”[3] Hotchkiss had involved materials and designs for doorknobs, where the patent claim at issue was directed to a purportedly unique doorknob construction composed of known materials and known design elements.[4] The Hotchkiss Court invalidated the claim, stating:
[U]nless more ingenuity and skill . . . were required . . . than were possessed by an ordinary mechanic acquainted with the business, there was an absence of that degree of skill and ingenuity which constitute essential elements of every invention. In other words, the improvement is the work of the skilful mechanic, not that of the inventor.[5]
Recognizing the historical case law back to Hotchkiss, and in further view of the legislative history of 35 U.S.C. § 103, the Graham Court held that § 103 was “a statutory expression of an additional requirement for patentability, originally expressed in Hotchkiss.”[6] Thus, § 103 did not effect a change in existing patent law.
The Graham Court went on to hold that § 103 “lends itself to several basic factual inquiries.”[7] These include “the scope and content of the prior art,” “differences between the prior art and the claims at issue,” and the “level of ordinary skill in the pertinent art.”[8] Moreover, “secondary considerations,” including but not limited to “commercial success,” “long felt but unsolved needs,” and “failure of others,” may be used as “indicia of obviousness or nonobviousness.”[9]
KSR International Co. v. Teleflex Inc., 550 U.S. 398 (2007)
By the end of the 20th century, in the interest of fostering predictability in the nonobviousness inquiry, the Federal Circuit had articulated a test for obviousness that required a showing by the patent challenger of a “teaching,” “suggestion,” or “motivation” to combine—the so-called “TSM test” within the prior art references that were asserted to invalidate the patent claim at issue. The propriety of the TSM test was challenged in KSR.
In KSR, the single patent claim at issue was directed to a mechanically adjustable automobile pedal to which an electronic sensor was attached for controlling engine throttling. Technology trends were such at the time that virtually all pedals were electronically controlled; moreover, adjustable pedals had been known and used for decades. The district court found that although none of the asserted prior art references explicitly taught mounting the electronic sensor in precisely the way recited in the claim, the prior art nevertheless taught arrangements having “little difference” from the claimed apparatus.[10] The district court held the claim invalid.
On appeal, the Federal Circuit reversed. The panel determined that even if the specific arrangement as recited in the claim were “obvious to try,” there was no specific teaching, motivation, or suggestion in the prior art references to combine the references as claimed.[11]
In a unanimous decision, the Supreme Court reversed the Federal Circuit, emphasizing the importance of a “flexible” obviousness inquiry as articulated in Graham.[12] Specifically, the Supreme Court determined that the Federal Circuit had erred in three ways: first, by holding that courts and patent examiners should look only to the problem that the patentee was trying to solve in evaluating a motivation to combine elements of prior art; second, by assuming that the skilled artisan will be led only to those elements of prior art designed to face the same problem faced by the inventor; and third, by overcompensating in rigidity to avoid hindsight bias.[13] As the Supreme Court stated, “the analysis need not seek out precise teachings directed to the specific subject matter of the challenged claim, for a court can take account of the inferences and creative steps that a person of ordinary skill in the art would employ.”[14]
Thus, the multifactored analysis articulated in Graham still stands as the relevant test, and it must be applied with sufficient flexibility to account for the creativity of the ordinarily skilled artisan.
The Enablement Requirement—35 U.S.C. § 112
In re Wands, 858 F.2d 731 (Fed. Cir. 1988)
In Wands, the Federal Circuit established a foundational framework for assessing whether a patent specification satisfies the enablement requirement under 35 U.S.C. § 112. The case arose from a patent application for immunoassay methods using high-affinity monoclonal IgM antibodies to detect hepatitis B surface antigen.[15] The U.S. Patent and Trademark Office (USPTO) rejected the application, concluding that the specification did not enable a person skilled in the art to make the claimed antibodies without undue experimentation.[16]
The Federal Circuit reversed, holding that the specification was enabling, and emphasized that “[e]nablement is not precluded by the necessity for some experimentation such as routine screening,” provided such experimentation is not “undue.”[17] The court clarified: “The key word is ‘undue,’ not ‘experimentation.’”[18]
To guide the undue experimentation inquiry, the court set forth eight factors, later known as the Wands factors:
(1) the quantity of experimentation necessary, (2) the amount of direction or guidance presented, (3) the presence or absence of working examples, (4) the nature of the invention, (5) the state of the prior art, (6) the relative skill of those in the art, (7) the predictability or unpredictability of the art, and (8) the breadth of the claims.[19]
Applying these factors, the Wands court found that the specification provided “considerable direction and guidance,” that “all of the methods needed to practice the invention were well known,” and that “[t]here was a high level of skill in the art.”[20] The applicants had successfully produced antibodies meeting claim limitations in each fusion experiment where they screened for the desired characteristics.[21]
Wands has had an enduring impact on patent practice. The eight-factor test remains the governing standard for enablement analysis across all technology areas. Wands endures because it balances the patent system’s competing interests: ensuring that inventors disclose enough to teach the public while recognizing that skilled practitioners routinely engage in experimentation as part of practicing any art.
Amgen Inc. v. Sanofi, 598 U.S 594 (2023)
In Amgen, the Supreme Court reaffirmed this framework established in Wands, with the Federal Circuit subsequently confirming that there is “no meaningful difference between Wands’ ‘undue experimentation’ and Amgen’s ‘[un]reasonable experimentation’ standards.”[22]
In Amgen, the Supreme Court unanimously held that Amgen’s broad patent claims covering an entire genus of cholesterol-lowering antibodies failed to satisfy the enablement requirement of 35 U.S.C. § 112(a).[23] The Court reaffirmed that “if a patent claims an entire class of processes, machines, manufactures, or compositions of matter, the patent’s specification must enable a person skilled in the art to make and use the entire class.”[24]
The dispute concerned antibody drugs that inhibit PCSK9, a naturally occurring protein that binds to and degrades LDL receptors responsible for removing “bad” cholesterol from the bloodstream.[25] Both Amgen and Sanofi developed PCSK9-inhibiting drugs. While Amgen’s 2011 patent claimed a specific antibody by its amino acid sequence, its 2014 patents purported to claim “the entire genus” of antibodies that bind to specific amino acids on PCSK9’s “sweet spot” and block PCSK9 from binding to LDL receptors.[26]
Amgen’s specification identified only 26 antibodies by their amino acid sequences but described two methods—the “roadmap” and “conservative substitution”—for generating additional antibodies. The roadmap directed scientists to generate candidate antibodies, then screen them to identify those with the claimed binding and blocking functions.
Conservative substitution required scientists to modify known antibodies by replacing select amino acids and testing whether the resulting antibodies retained function.[27]
The Amgen Court found these methods inadequate for enablement. Drawing parallels to cases from 1854, 1895, and 1928, the Court held that Amgen’s approaches “amount to little more than two research assignments” requiring “painstaking experimentation.”[28] The specification left scientists “forced to engage in” trial-and-error discovery—“not enablement” but rather “a hunting license.”[29]
The Amgen Court emphasized that “the more a party claims, the broader the monopoly it demands, the more it must enable.”[30] A specification may permit “a reasonable amount of experimentation,” and disclosing “some general quality” running through a claimed class may suffice.[31] But Amgen’s claims covered potentially millions of undisclosed antibodies without enabling their production.
Amgen has significant implications for biotechnology patent practice. The decision reinforces that functional genus claims require robust enabling disclosure—not merely instructions for trial-and-error screening. The decision signals heightened scrutiny for broad functional claims, particularly in the unpredictable arts.
Following Amgen, the USPTO issued guidance confirming that the Wands factors remain the governing standard for enablement analysis and expressly directing examiners to continue applying the Wands factors “regardless of the technology.”[32]
A Modern Framework for Claim Construction
Markman v. Westview Instruments, Inc., 517 U.S. 370 (1996)
In Markman, the Supreme Court held definitively that claim construction is a legal question to be determined by the court (and not a question of fact to be resolved by the fact finder).[33] Markman signaled the start of modern claim construction, resulting in the common practice of claim construction hearings (also referred to as Markman hearings) and paving the way for de novo review of claim construction determinations by the Federal Circuit.
The outcome of a Markman hearing can often be case-dispositive. A narrow construction of a term may eradicate a plaintiff’s infringement position. Conversely, a broad construction may make establishing infringement easy but increases the risk of the claim being invalid due to prior art.
The outcome of a Markman hearing also impacts discovery (potentially narrowing the relevant scope), drives summary judgment (for noninfringement/infringement as a matter of law), and often leads to settlement (allowing more detailed evaluations of the strengths or weaknesses of a case).
While Markman’s holding shifted district court litigation by assigning claim construction authority to the district judges, settling claim construction as a question of law also expanded the Federal Circuit’s influence over patent law, as questions of law are reviewed de novo. Although some subsequent decisions have adjusted this standard to some extent,[34] the ultimate interpretation of claim terms is a legal conclusion. Through de novo review, the Federal Circuit has used subsequent cases, such as Phillips v. AWH Corp., to shape claim construction into its modern form.
Phillips v. AWH Corp., 415 F.3d 1303 (Fed. Cir. 2005)
If Markman laid the foundation for modern claim construction, Phillips is the analytical scaffolding. Post-Markman, two competing frameworks for claim construction had been utilized by the Federal Circuit and by district courts. The first framework relied heavily on dictionary definitions in construing disputed terms, with a subsequent check to the patent specification to determine if the inventor had contradicted or modified the dictionary definition.[35] The second framework, which was ultimately adopted in Phillips, begins with the language of the claims, read in view of the
specification and the prosecution history (referred to collectively as “intrinsic evidence”).[36]
Beginning from the “bedrock principle” that “the claims of a patent define the invention to which the patentee is entitled the right to exclude,” the Federal Circuit reiterated that claim construction begins with the words of the claims themselves.[37] As noted by the court, a person of ordinary skill in the art is deemed to read the claim terms in both the context of the particular claim and the context of the entire patent, including the specification.[38] The court also indicated that the prosecution history of a patent can “inform the meaning of the claim language by demonstrating how the inventor understood the invention and whether the inventor limited the invention in the course of prosecution.”[39]
While the Federal Circuit indicated that extrinsic evidence, such as dictionary definitions or expert testimony, can in some instances be useful in understanding claim terms, it is “unlikely to result in a reliable interpretation of patent claim scope unless considered in the context of the intrinsic evidence.”[40] In other words, the Federal Circuit established a hierarchy of evidence for claim construction, beginning with the claims, the specification, and the prosecution history (the intrinsic evidence) and only using extrinsic evidence in the context of the intrinsic evidence.
Although other decisions have made minor adjustments to the structure, the foundation and scaffolding established in Markman and Phillips remains the analytical basis of modern claim construction.
Doctrine of Equivalents/Prosecution History Estoppel
Warner-Jenkinson Co. v. Hilton Davis Chemical Co., 520 U.S. 17 (1997)
In Warner-Jenkinson, the Supreme Court confirmed the vitality of the doctrine of equivalents, while establishing that a patent’s prosecution history estoppel applies to amendments made for “a substantial reason related to patentability.”[41]
The petitioner in Warner-Jenkinson argued that the common law doctrine of equivalents, as articulated in earlier cases such as Graver Tank,[42] had been legislatively obviated by the 1952 Act.
The Warner-Jenkinson Court determined otherwise, stating:
Today we adhere to the doctrine of equivalents. The determination of equivalence should be applied as an objective inquiry on an element-by element basis. Prosecution history estoppel continues to be available as a defense to infringement, but if the patent holder demonstrates that an amendment required during prosecution had a purpose unrelated to patentability, a court must consider that purpose in order to decide whether an estoppel is precluded.[43]
Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co. (SMC), 535 U.S. 722 (2002)
In Festo, the Supreme Court revisited the intersection of the doctrine of equivalents and prosecution history estoppel—foundational concepts that define patent protection boundaries. Building on Warner-Jenkinson, Festo addressed whether such an estoppel should operate as a complete bar.
Festo Corporation sued SMC for infringement of patents covering a magnetic rodless cylinder. SMC’s device did not literally infringe but was alleged equivalent. SMC argued estoppel because Festo had narrowed claims during prosecution—adding the limitations of a pair of sealing rings or a magnetizable sleeve—to satisfy 35 U.S.C. § 112.[44]
The Federal Circuit, sitting en banc, adopted a “complete bar” rule: any narrowing amendment would entirely foreclose equivalents for that element.[45] The Supreme Court unanimously rejected this rigid approach, instead holding that prosecution history estoppel applies when an applicant narrows a claim “to satisfy any requirement of the Patent Act”—not just amendments avoiding prior art.[46] However, the Court established a rebuttable presumption rather than an absolute bar: “the patentee should bear the burden of showing that the amendment does not surrender the particular equivalent in question.”[47]
The Court identified three potential means of rebuttal: (1) the equivalent was unforeseeable at the time of the application; (2) the amendment’s rationale bore only a tangential relation to the equivalent; or (3) other reasons why the patentee could not reasonably have described the substitute in question.[48] These rebuttals are exceptions to an exception (prosecution history estoppel), which is itself an exception—to the doctrine of equivalents.
Festo’s impact on patent practice has been substantial. Critics had warned that the complete bar would deprive most patentees of recourse to equivalents, since most claims are amended during prosecution. By restoring flexibility, the Court protected settled expectations while demanding accountability.
Since 2002, the rebuttable presumption framework has become embedded in patent litigation. The Federal Circuit has repeatedly applied the three rebuttal criteria in cases, refining how patentees overcome estoppel. Commentators have characterized “foreseeability” as a unifying principle extending into the doctrine of equivalents itself.
Festo also impacted claim-drafting strategy, forcing applicants to anticipate estoppel consequences and build prosecution records explaining each amendment’s purpose. Two decades later, Festo’s flexible-bar approach endures as the governing standard, ensuring prosecution history estoppel remains “tied to its underlying purpose,”[49] while providing patentees a fair opportunity to argue infringement under the doctrine of equivalents based on the three presumption rebuttals.
Subject Matter Eligibility—35 U.S.C. § 101
In life science patent prosecution, drafting claims and patent applications that keep in mind ever-evolving changes to patent eligibility under 35 U.S.C. § 101 continues to be a challenge. While important cases such as Diamond v. Chakrabarty[50] and Diamond v. Diehr[51] continue to provide the base framework for subject matter eligibility for life science matters, the two-part Alice/Mayo test based on Mayo Collaborative Services v. Prometheus Laboratories, Inc. and Alice Corp. Pty. Ltd. v. CLS Bank International provides the structure that guides the determination of patent eligibility in modern practice.
Mayo Collaborative Services v. Prometheus Laboratories, Inc., 566 U.S. 66 (2012)
Mayo serves as the modern anchor for § 101 natural-law jurisprudence in the life sciences. In Mayo, the claims at issue recited administering a thiopurine drug, determining metabolite levels, and inferring whether to adjust dosage based on a threshold correlation. The Supreme Court held the claims ineligible because they were directed to a natural law—the relationship between metabolite concentrations and therapeutic efficacy/toxicity—and the additional steps were merely “well-understood, routine, conventional” activity.[52] The Court also crystallized the now-familiar twostep inquiry: (1) ask whether the claims are directed to a law of nature, natural phenomenon, or abstract idea; and, if so, (2) determine whether the elements, individually and in combination, add significantly more, i.e., an “inventive concept,” that transforms the claim into a patent-eligible application.[53]
The practical lesson of Mayo is straightforward: Claims that diagnose or optimize a therapeutic by detecting or correlating biomarkers are vulnerable when expressed as a natural correlation implemented with standard sampling, detection, and analysis. Generic “apply it” language, or conventional pre- and post-solution activity (administering, measuring, reporting), will not salvage eligibility. Mayo pushes drafting toward concrete technical implementations that do more than use the correlation; claims should integrate such natural correlations and relationships into a nonconventional methodology or improved technology that changes how the laboratory technique or clinical workflow operates, not merely what it infers.
Alice Corp. Pty. Ltd. v. CLS Bank International, 573 U.S. 208 (2014)
Although Alice addressed computer-implemented financial claims, the formal two-step framework that courts now apply across technologies, including the life sciences, was solidified further. The Supreme Court held that implementing an abstract idea, e.g., intermediated settlement, on a generic computer does not confer patent eligibility. After identifying the abstract idea at step 1, the Court found that there was no “inventive concept” at step 2 because the computer functions were routine and conventional.[54]
For software-implemented inventions, Alice had a profound effect on patent litigation—resulting in the invalidation of many patents, particularly those directed to business methods.
For life science practice, the holding in Alice reinforces that field-of-use limitations and generic implementation cannot convert ineligible subject matter into patent-eligible claims and emphasizes that any “inventive concept” must be grounded in the claim elements and their ordered combination. Practically applied to diagnostics and bioinformatics, Alice steers courts and examiners to analogize data analysis, information processing, and reporting to “abstract ideas,” and to scrutinize whether any recited computational or laboratory implementation is specific, technologically meaningful, and nonconventional.
Ariosa Diagnostics, Inc. v. Sequenom, Inc., 788 F.3d 1371 (Fed. Cir. 2015)
In Ariosa, the Federal Circuit applied the Alice/Mayo framework to prenatal diagnostics and narrowed eligibility for biomarker detection, holding that the claim methods for detecting paternally inherited cell-free fetal DNA (cffDNA) in maternal plasma for prenatal diagnosis were patent ineligible. The claims to detecting cffDNA in maternal blood are directed to a natural phenomenon (step 1: yes), and the steps of amplifying and detecting DNA with PCR and related techniques were, in the court’s view, routine and conventional (step 2: no). Despite acknowledging the groundbreaking nature of the discovery, the panel concluded that the claims failed step 2 because they merely instructed practitioners to apply known techniques to the newly discovered natural phenomenon.[55]
In a way, Ariosa reminds practitioners that natural phenomena and laws of nature require “significantly more” such as transformation by “the hand of man” to be patent eligible. Simply discovering, or even characterizing, a natural phenomenon, subject, or law does not, without more, yield eligible claims, especially if the implementation uses techniques that are considered routine and conventional. Claims in diagnostics, for example, should embed new discoveries in nonconventional technical solutions, such as in a specifically configured assay, a bespoke samplepreparation protocol that departs from or clearly improves upon standard practice, or a data-processing pipeline that materially improves the function of the testing technology.
Mayo, Alice, and Ariosa set a demanding template for eligibility under § 101. Prosecutors should anchor eligibility in the claim language with technical specificity: precise assay architectures; nonconventional reagent systems or component designs tied to unexpected performance; engineered workflows that reduce noise, bias, or sample loss in ways that are not routine at filing; and clearly articulated improvements to the functioning of the testing technology. Where claims hinge on parameters such as reaction conditions, signal extraction, or data normalization, the claims should tie those parameters to technical effects beyond merely achieving the correlation.
For diagnostics, claims that detect a biomarker and correlate it with a clinical outcome are high risk if the lab steps mirror standard practice and the analytics read like generic information processing. For therapeutics and personalized medicine, the case law differentiates between claims that merely recognize a natural relationship and those that apply it through a particular treatment regimen. Mayo warns that dosage optimization based on metabolite levels is vulnerable if the claims read like an instruction to apply a correlation with routine steps. Later Federal Circuit decisions have been more receptive to claims that specify a concrete treatment protocol that changes patient care based on a diagnostic assessment, but the drafting must make the application more than a mental step or generic recommendation.[56]
For bioinformatics and computational biology, Alice sharpens the focus on whether claimed analytics are merely abstract data processing or instead recite a particularized, improved computational technique tied to biological data. To enhance eligibility, practitioners should emphasize how the algorithm improves the operation of the analytical tool or the accuracy, speed, or resource efficiency of the testing platform, as opposed to merely producing a clinical inference.[57] Purely mental steps or results-oriented language, untethered to specific computational architectures or unconventional processing, invites step 2 invalidation.
Overall, these cases counsel a diversified claim strategy that considers preparing multiple claim types, including methods of preparation or manufacture, methods of treatment, composition claims that do not run afoul of product-of-nature limitations, and device or system claims capturing assay configurations. The specification should document and robustly support what is asserted to be novel and nonconventional, provide technical rationale for why the claimed steps achieve performance improvements, and supply examples that tie parameters to measurable technical effects in order to support the Alice/Mayo step 2 “inventive concept” arguments, enabling applicants to rebut examiner assertions of conventionality with evidence grounded in the disclosure.
Inequitable Conduct
Therasense, Inc. v. Becton, Dickinson & Co., 649 F.3d 1276 (Fed. Cir. 2011)
At its heart, the doctrine of inequitable conduct relates to fairness, preventing patents obtained through egregious misconduct from being enforced.[58] The doctrine evolved from three Supreme Court cases involving “unclean hands” in the form of manufactured and/or suppressed evidence, such as hiding a prior use,[59] manufacturing evidence of novelty and nonobviousness,[60] and perjury before the USPTO during an interference.[61] According to the Federal Circuit, prior to Therasense, “[t]he habit of charging inequitable conduct in almost every major patent case has become an absolute plague.”[62] In particular, the Federal Circuit found that “low standards for intent and materiality had inadvertently led to . . . increased adjudication cost and complexity, reducing likelihood of settlement, burdened courts, strained PTO resources, increased PTO backlog, and impaired patent quality.”[63]
In response to this “plague,” the Federal Circuit established an intent and materiality requirement.[64] The Federal Circuit stressed that intent and materiality are separate requirements that each must be met for inequitable conduct. The materiality standard was established as a “but-for” standard, e.g., a prior art reference is “but-for material if the PTO would not have allowed a claim had it been aware of the undisclosed prior art.”[65] The heightened standards for intent and materiality changed the landscape for inequitable conduct, altering the defense from one of common assertion to one only used in rare situations that meet the heightened standard.
Patent Litigation Venue
TC Heartland LLC v. Kraft Foods Group Brands LLC, 581 U.S. 258 (2017)
The special venue statute concerning U.S. patent disputes in federal court, 28 U.S.C. § 1400(b), provides that “[a]ny civil action for patent infringement may be brought in the judicial district where the defendant resides, or where the defendant has committed acts of infringement and has a regular and established place of business.” In the 1942 Stonite case, the Supreme Court held explicitly that the special patent venue statute was the “exclusive provision controlling venue in patent infringement proceedings.”[66] This conclusion was later reinforced in the Fourco case in 1957.[67]
By 1990, however, the federal jurisdictional statutes had been amended, leading the Federal Circuit to conclude that the special venue statute had been displaced in patent cases in favor of the general venue statute, 28 U.S.C. § 1391.[68] Under § 1391, a party accused of infringing a patent could be sued in any judicial district in which the party was subject to personal jurisdiction—which for a large corporation often means just about anywhere the company sells products. Relying on the line of cases beginning with VE Holding, the Federal Circuit declined to grant a writ of
mandamus sought by TC Heartland seeking transfer of the case to its home district.[69]
In a unanimous decision, the Supreme Court reversed the Federal Circuit. As the TC Heartland Court stated: “In Fourco, this Court definitively and unambiguously held that the word ‘reside[nce]’ in § 1400(b) has a particular meaning as applied to domestic corporations: It refers only to the State of incorporation. Congress has not amended § 1400(b) since Fourco, and neither party asks us to reconsider our holding in that case.”[70]
Thus, for domestic corporations, a defendant can only be sued either where it is incorporated or where it has committed acts of infringement and has a regular and established place of business. A foreign defendant, on the other hand, can be sued in any judicial district.[71]
In the wake of its issuance, the TC Heartland decision had a significant impact on the distribution of patent cases across the United States although that has moderated somewhat over time.
Conclusion
The last 60 years have seen both tremendous shifts in the importance—and pure number—of patents in the United States, along with the affirmation of principles dating back to the early republic. Patent law continues to evolve, and this evolution continues to be influenced by the tension between public accessibility and private reward. With groundbreaking technological changes ahead in the coming years, patent law will need to further adapt, though the same fundamental tensions will doubtless remain.
D. Stuart Bartow is a partner at Duane Morris, where he represents clients from around the globe in intellectual property and other complex commercial matters, with particular emphasis on disputes concerning semiconductors, electronics, computer hardware and software, and clean energy technology. He can be reached at dsbartow@duanemorris.com. Jiazhong (Jason) Luo, PhD is a partner at Duane Morris, where his practice focuses on all aspects of patent law, including patent prosecution, due diligence, opinion, and litigation. He can be reached at jluo@duanemorris.com. Daniel Tarr is a partner at Duane Morris, where his practice focuses on patent procurement and prosecution, enforcement and licensing, and patent litigation. He can be reached at dtarr@duanemorris.com. Jenny Mae Samson, PhD, is a patent agent at Duane Morris, where she assists with the prosecution of patent applications and other patent matters, including matters involving molecular diagnostics, immunotherapies, flow cytometry, and diagnostic instrumentation. She can be reached at jsamson@duanemorris.com.
Endnotes
1. Graham v. John Deere Co. of Kansas City, 383 U.S. 1, 3 (1966).
2. U.S. Const. art. I, § 8, cl. 8.
3. Graham, 383 U.S. at 11.
4. Hotchkiss v. Greenwood, 52 U.S. 248 (1850).
5. Graham, 383 U.S. at 11 (quoting Hotchkiss, 52 U.S. at 267).
6. Id. at 15.
7. Id. at 17.
8. Id.
9. Id. at 17–18.
10. KSR Int’l Co. v. Teleflex Inc., 550 U.S. 398, 413 (2007).
11. Id. at 414.
12. Id. at 415.
13. Id. at 420.
14. Id. at 418.
15. In re Wands, 858 F.2d 731, 733 (Fed. Cir. 1988).
16. Id. at 735.
17. Id. at 736–37.
18. Id. at 737.
19. Id.
20. Id. at 740.
21. Id.
22. Baxalta Inc. v. Genentech, Inc., 81 F.4th 1362, 1367 n.4 (Fed. Cir. 2023).
23. Amgen Inc. v. Sanofi, 598 U.S 594, 604–16 (2023).
24. Id. at 610.
25. Id. at 598–99, 601–02.
26. Id. at 602.
27. Id. at 603.
28. Id. at 610–14 (citing O’Reilly v. Morse, 56 U.S. (15 How.) 62 (1854); Consolidated Elec. Light Co. v. McKeesport Light Co.
(The Incandescent Lamp Patent), 159 U.S. 465 (1895); Holland Furniture Co. v. Perkins Glue Co., 277 U.S. 245 (1928)).
29. Id. at 614.
30. Id. at 613.
31. Id. at 611–13.
32. Guidelines for Assessing Enablement in Utility Applications and Patents in View of the Supreme Court Decision in Amgen
Inc. et al. v. Sanofi et al., 89 Fed. Reg. 1563 (Jan. 10, 2024); see also Manual of Patent Examining Procedure (MPEP)
§ 2164.01 (9th ed., Rev. 01.2024).
33. Markman v. Westview Instruments, Inc., 517 U.S. 370, 384–91 (1996).
34. See Teva Pharms. USA, Inc. v. Sandoz, Inc., 574 U.S. 318 (2015) (holding that review of subsidiary factual matters made in
the course of claim construction must use a clear error standard).
35. See, e.g., Tex. Digit. Sys., Inc. v. Telegenix, Inc., 308 F.3d 1193 (Fed. Cir. 2002).
36. See Phillips v. AWH Corp., 415 F.3d 1303, 1315 (Fed. Cir. 2005).
37. Id. at 1312.
38. Id. at 1313.
39. Id. at 1317.
40. Id. at 1319.
41.Warner-Jenkinson Co. v. Hilton Davis Chem. Co., 520 U.S. 17, 33 (1997).
42. Graver Tank & Mfg. Co. v. Linde Air Prods. Co., 339 U.S. 605 (1950).
43. 520 U.S. at 40–41.
44. Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co. (SMC), 535 U.S. 722, 728–29 (2002).
45. Id. at 729–30.
46. Id. at 736.
47. Id. at 740.
48. Id. at 740–41.
49. Id. at 734.
50. 447 U.S. 303 (1980).
51. 450 U.S. 175 (1981).
52. Mayo Collaborative Servs. v. Prometheus Lab’ys, Inc., 566 U.S. 66, 73 (2012).
53. Id. at 72–73.
54. Alice Corp. Pty. Ltd. v. CLS Bank Int’l, 573 U.S. 208, 225 (2014).
55. Ariosa Diagnostics, Inc. v. Sequenom, Inc., 788 F.3d 1371, 1377–78 (Fed. Cir. 2015).
56. See, e.g., Vanda Pharms. Inc. v. West-Ward Pharms. Int’l Ltd., 887 F.3d 1117 (Fed. Cir. 2018) (claims requiring specific dosing
regimen based on genotype held eligible as method of treatment); Illumina, Inc. v. Ariosa Diagnostics, Inc., 967 F.3d 1319 (Fed.
Cir. 2020) (claims to method of preparing DNA fraction enriched in cffDNA by size selection held eligible as method of preparation
with human-engineered parameters); CareDx, Inc. v. Natera, Inc., 40 F.4th 1371 (Fed. Cir. 2022) (claims to detecting organ
transplant rejection by measuring donor cfDNA held ineligible where claims merely applied conventional techniques to detect natural
correlation).
57. See CardioNet, LLC v. InfoBionic, Inc., 955 F.3d 1358 (Fed. Cir. 2020) (claims to cardiac monitoring device with improved detection algorithm held eligible where technological improvement was the focus, not the underlying physiological data).
58. See Therasense, Inc. v. Becton, Dickinson & Co., 649 F.3d 1276, 1285 (Fed. Cir. 2011).
59. Keystone Driller Co. v. Gen. Excavator Co., 290 U.S. 240 (1933).
60. Hazel-Atlas Glass Co. v. Hartford-Empire Co., 322 U.S. 238 (1944), overruled on other grounds by, Standard Oil Co. of
Cal. v. United States, 429 U.S. 17 (1976).
61. Precision Instrument Mfg. Co. v. Auto. Maint. Mach. Co., 324 U.S. 806 (1945).
62. Therasense, 649 F.3d at 1289.
63. Id. at 1290.
64. Id.
65. Id. at 1291.
66. Stonite Prods. Co v. Melvin Lloyd Co., 315 U.S. 561, 562 (1942).
67. Fourco Glass Co. v. Transmirra Prods. Corp., 353 U.S. 222, 229 (1957).
68. VE Holding Corp. v. Johnson Gas Appliance Co., 917 F.2d 1574 (Fed. Cir. 1990).
69. In re TC Heartland LLC, 821 F.3d 1338 (Fed. Cir. 2016).
70. TC Heartland LLC v. Kraft Foods Group Brands LLC, 581 U.S. 258, 267–68 (2017) (alteration in original) (footnote
omitted).
71. See Brunette Mach. Works, Ltd. v. Kockum Indus., Inc., 406 U.S. 706 (1972).
(Landslide, Vol. 18, No. 4, June/July 2026 is available in full at the American Bar Association website, subscription required.)
