PRELIMINARY PRINT 

Volume 598 U. S. Part 2 

Pages 594–616 

OFFICIAL REPORTS 

OF 

THE SUPREME COURT 

May 18, 2023 

REBECCA A. WOMELDORF 

reporter of decisions 

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NOTICE: This preliminary print is subject to formal revision before 

the bound volume is published. Users are requested to notify the Reporter 

of Decisions, Supreme Court of the United States, Washington, D.C. 20543, 

pio@supremecourt.gov, of any typographical or other formal errors. 
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594 OCTOBER TERM, 2022 

Syllabus 

AMGEN INC. et al. v. SANOFI et al. 

certiorari to the united states court of appeals for 

the federal circuit 

No. 21–757. Argued March 27, 2023—Decided May 18, 2023 

This case concerns patents covering antibodies engineered by scientists 

that help reduce levels of low-density lipoprotein (LDL) cholesterol, 

sometimes called bad cholesterol because it can lead to cardiovascular 

disease, heart attacks, and strokes. To treat patients with high LDL 

cholesterol, scientists explored how antibodies might be used to inhibit 

PCSK9—a naturally occurring protein that binds to and degrades LDL 

receptors responsible for extracting LDL cholesterol from the bloodstream. Two pharmaceutical companies—Amgen and Sanof—each developed a PCSK9-inhibiting drug. In 2011, Amgen obtained a patent 

for the antibody employed in its drug, and Sanof received one covering 

the antibody used in its drug. Each patent describes the relevant antibody by its unique amino acid sequence. The dispute in this case concerns two additional patents Amgen obtained in 2014 that relate back 

to the company's 2011 patent. These later-issued patents purport to 

claim for Amgen “the entire genus” of antibodies that (1) “bind to specifc amino acid residues on PCSK9,” and (2) “block PCSK9 from binding 

to [LDL receptors].” 872 F. 3d 1367, 1372. As part of its submission 

to the patent offce, Amgen identifed the amino acid sequences of 26 

antibodies that perform these two functions. Amgen then described 

two methods—one Amgen called “the roadmap” and a second it called 

“conservative substitution”—that scientists could use to make other antibodies that perform the binding-and-blocking functions described in 

the claims. 

After Amgen obtained the 2014 patents, it sued Sanof for infringement. Sanof replied that it was not liable to Amgen for infringement 

because Amgen's relevant claims were invalid under the Patent Act's 

“enablement” requirement. That provision requires a patent applicant 

to describe the invention “in such full, clear, concise, and exact terms as 

to enable any person skilled in the art . . . to make and use the [invention].” 35 U. S. C. § 112(a). Sanof characterized the methods Amgen 

outlined for generating additional antibodies as amounting to little more 

than a trial-and-error process of discovery, and thus contended that Amgen's patents failed to meet the enablement requirement because they 

sought to claim for Amgen's exclusive use potentially millions more antibodies than the company had taught persons skilled in the art to make. 

Both the district court and the Federal Circuit sided with Sanof. 
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Syllabus 

Held: The courts below correctly concluded that Amgen failed “to enable 

any person skilled in the art . . . to make and use the [invention]” as 

defned by the relevant claims. Pp. 604–616. 

(a) The patent “bargain” describes the exchange that takes place 

when an inventor receives a limited term of “protection from competitive exploitation” in exchange for bringing “new designs and technologies into the public domain through disclosure” for the beneft of all. 

Bonito Boats, Inc. v. Thunder Craft Boats, Inc., 489 U. S. 141, 150–151. 

From the Patent Act's beginnings, Congress has sought to ensure the 

beneft of this bargain for the public by requiring the patent applicant 

to deposit a “specifcation . . . so particular . . . as not only to distinguish 

the invention or discovery from other things before known and used, 

but also to enable a workman or other person skilled in the art or manufacture . . . to make, construct, or use the same.” 1 Stat. 110. Over 

time, Congress has left this “enablement” obligation largely intact. 

This Court has addressed the enablement requirement many times, 

and its decisions in O'Reilly v. Morse, 15 How. 62, The Incandescent 

Lamp Patent, 159 U. S. 465, and Holland Furniture Co. v. Perkins Glue 

Co., 277 U. S. 245, reinforce the simple statutory command: If a patent 

claims an entire class of processes, machines, manufactures, or compositions of matter, the patent's specifcation must enable a person skilled 

in the art to make and use the entire class. In Morse, for example, the 

Court held that one of the claims in Morse's patent for a telegraphic 

system was “too broad, and not warranted by law.” 15 How., at 113. 

The problem was that the claim covered all means of achieving telegraphic communication, yet Morse's specifcation did not describe how 

to make or use them all. See id., at 113–117. In Incandescent Lamp, 

inventors of an “electric lamp” with an “incandescing conductor” made 

of “carbonized paper” claimed that a lamp created by Thomas Edison 

infringed their patent because it used bamboo as a conductor. The 

Court sided with Edison because the rival inventors, rather than confning their claim to carbonized paper, “made a broad claim for every fbrous and textile material.” 159 U. S., at 472. That broad claim 

“might” have been permissible, the Court allowed, if the inventors had 

disclosed “a quality common” to fbrous and textile substances that made 

them “peculiarly” adapted to incandescent lighting, but they did not. 

Ibid. Finally, in Holland Furniture, a company that had developed a 

starch glue that was similar enough to animal glue to be used for wood 

veneering included a claim in its patent covering all “starch glue which, 

[when] combined with about three parts or less . . . of water, will have 

substantially the same properties as animal glue.” 277 U. S., at 251. 

The specifcation described the key input—the “starch ingredient”—in 

terms of its “use or function” rather than its “physical characteristics or 

chemical properties.” Id., at 256. The problem, as the Court put it, 
596 AMGEN INC. v. SANOFI 

Syllabus 

was that “[o]ne attempting to use or avoid the use of [the] discovery as 

so claimed and described functionally could do so only after elaborate 

experimentation” with different starches. Id., at 257. 

All this is not to say a specifcation always must describe with particularity how to make and use every single embodiment within a claimed 

class. It may suffce to give an example if the specifcation also discloses “some general quality . . . running through” the class that gives 

it “a peculiar ftness for the particular purpose.” Incandescent Lamp, 

159 U. S., at 475. Nor is a specifcation necessarily inadequate just because it leaves the skilled artist to engage in some measure of adaptation or testing. See, e. g., Wood v. Underhill, 5 How. 1, 4–5. A specifcation may call for a reasonable amount of experimentation to make and 

use a claimed invention, and reasonableness in any case will depend 

on the nature of the invention and the underlying art. See Minerals 

Separation, Ltd. v. Hyde, 242 U. S. 261, 270–271. Pp. 604–612. 

(b) Turning to the patent claims at issue in this case, Amgen's claims 

sweep much broader than the 26 exemplary antibodies it identifes by 

their amino acid sequences. Amgen has failed to enable all that it has 

claimed, even allowing for a reasonable degree of experimentation. 

Amgen's claims bear more than a passing resemblance to the broadest 

claims in Morse, Incandescent Lamp, and Holland Furniture. While 

Amgen seeks to monopolize an entire class of things defned by their 

function—every antibody that both binds to particular areas of the 

sweet spot of PCSK9 and blocks PCSK9 from binding to LDL receptors—the record refects that this class of antibodies does not include 

just the 26 that Amgen has described by their amino acid sequences, 

but a vast number of additional antibodies that it has not. 

Amgen insists that its claims are nevertheless enabled because scientists can make and use every functional antibody if they simply follow 

the “roadmap” or “conservative substitution.” These two approaches, 

however, amount to little more than two research assignments. The 

“roadmap” merely describes step-by-step Amgen's own trial-and-error 

method for fnding functional antibodies. Not much different, “conservative substitution” requires scientists to make substitutions to the amino 

acid sequences of antibodies known to work and then test the resulting 

antibodies to see if they do too. 

Amgen's alternative arguments lack merit. Amgen first suggests 

that the Federal Circuit erred by confating the question whether an 

invention is enabled with the question how long may it take a person 

skilled in the art to make every embodiment within a broad claim. But 

the Federal Circuit made clear that it was not treating as dispositive 

the cumulative time and effort required to make the entire class of antibodies. Amgen next argues that the Patent Act supplies a single, uniPage Proof Pending Publication
Cite as: 598 U. S. 594 (2023) 597 

Syllabus 

versal enablement standard, while the Federal Circuit applied a higher 

standard to Amgen's claims that encompass an entire genus of embodiments defned by their function. The Court agrees in principle that 

there is one statutory enablement standard, but the Federal Circuit's 

treatment in this case is entirely consistent with Congress's directive 

and this Court's precedents. Finally, while Amgen warns that a ruling 

against it risks destroying the incentives that lead to breakthrough inventions, since 1790 Congress has included an enablement mandate as 

one feature among many designed to achieve the balance it wishes to 

strike between incentivizing inventors and ensuring the public receives 

the full beneft of their innovations. In this case, the Court's duty is to 

enforce the statutory enablement requirement according to its terms. 

Pp. 612–616. 

987 F. 3d 1080, affrmed. 

Gorsuch, J., delivered the opinion for a unanimous Court. 

Jeffrey A. Lamken argued the cause for petitioners. 

With him on the briefs were Michael G. Pattillo, Jr., Sarah 

J. Newman, Jonathan P. Graham, Stuart L. Watt, Wendy 

A. Whiteford, Emily C. Johnson, Keith R. Hummel, Andrei 

Harasymiak, and Sarah C. Columbia. 

Paul D. Clement argued the cause for respondents. With 

him on the brief were C. Harker Rhodes IV, David K. Barr, 

George W. Hicks, Jr., Nathan S. Mammen, Matthew M. Wolf, 

Daniel L. Reisner, Deborah Fishman, and Victoria L. 

Reines. 

Colleen E. Roh Sinzdak argued the cause for the United 

States as amicus curiae urging affrmance. With her on the 

brief were Solicitor General Prelogar, Principal Deputy 

Assistant Attorney General Boynton, Deputy Solicitor General Stewart, Daniel Tenny, Brian J. Springer, Thomas W. 

Krause, Farheena Y. Rasheed, Amy J. Nelson, and Monica 

B. Lateef.* 

*Briefs of amici curiae urging reversal were fled for AbbVie Inc. by 

Jonathan S. Massey; for the Alliance of U. S. Startups and Inventors for 

Jobs et al. by Robert P. Taylor; for the Chemistry and Law Division of 

the American Chemical Society by James C. Carver, Justin J. Hasford, 

Matthew J. Hlinka, and Kendrew H. Colton; for Diversifed Researchers 

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598 AMGEN INC. v. SANOFI 

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Justice Gorsuch delivered the opinion of the Court. 

The development of antibody drugs has yielded lifechanging therapies. Individuals across the world now rely 

on antibody drugs to treat conditions ranging from Crohn's 

disease to cancer. This case concerns patents covering antibodies that help reduce levels of low-density lipoprotein cholesterol, sometimes called LDL cholesterol (for the obvious 

reason) or bad cholesterol (because it can lead to cardiovascular disease, heart attacks, and strokes). 

and Innovators by Jeffrey P. Kushan, Joshua J. Fougere, Matthew Mahoney, and Steven J. Horowitz; for the Fynder Group, Inc., by Matthew J. 

Dowd; for GSK plc by John M. Desmarais and Todd L. Krause; for Instil 

Bio, Inc., by John R. Labbe; for the Intellectual Property Law Association 

of Chicago by Charles W. Shifey, Robert H. Resis, John M. Augustyn, and 

Tiffany Gehrke; for Intellectual Property Professors by Mark A. Lemley, 

pro se; for the National Association of Patent Practitioners, Inc., by 

Xhavin Sinha and Louis J. Hoffman; for the New York Intellectual Property Law Association by Melvin C. Garner, Robert M. Isackson, Robert 

J. Rando, and Charles E. Miller; and for REGENXBIO Inc. et al. by 

William G. Jenks. 

Briefs of amici curiae urging affrmance were fled for the American 

Intellectual Property Law Association by James D. Crowne; for Arnold 

Ventures et al. by Lauren A. Degnan; for the Association for Accessible 

Medicines by Matthew S. Hellman and Adam G. Unikowsky; for Eli Lilly 

and Co., et al. by Katherine A. Helm, Michael H. McGinley, and Duane 

C. Marks; for Fresenius Kabi USA, LLC, by Neil Lloyd; for Genentech, 

Inc., et al. by Melanie L. Bostwick and Karen Boyd; for Intellectual Property Law Professors et al. by Edgar H. Haug; for Law Professors by 

Jeremy P. Oczek and Joshua D. Sarnoff, pro se; for Pfzer Inc. by Dimitrios T. Drivas, John P. Scheibeler, and Amit H. Thakore; for the Public 

Interest Patent Law Institute by Nina Srejovic and Alex Moss; for Small 

and Medium Biotechnology Companies by Mark A. Perry, Zachary D. 

Tripp, and Robert B. Niles-Weed; for Unifed Patents, LLC, by Lisa M. 

Ferri, Richard J. McCormick, Andrew J. Pincus, and Jonathan Stroud; 

for Viatris Inc. by Steffen N. Johnson and Richard Torczon; for Robin 

Feldman by Gideon A. Schor and Ms. Feldman, pro se; and for Gregory 

Paul Winter et al. by Sophie F. Wang and Eric J. Marandett. 

Briefs of amici curiae were fled for the High Tech Inventors Alliance 

et al. by John D. Vandenberg and Sarah E. Jelsema; and for the Intellectual Property Owners Association by Vanessa Yen and Evan Diamond. 
Cite as: 598 U. S. 594 (2023) 599 

Opinion of the Court 

The case comes to us this way. Several years ago, petitioners (Amgen) obtained two patents. Together, these patents claim a monopoly over all antibodies that (1) bind to 

specifc amino acids on a naturally occurring protein known 

as PCSK9, and (2) block PCSK9 from impairing the body's 

mechanism for removing LDL cholesterol from the bloodstream. Soon after receiving these patents, Amgen sued respondents (Sanof) for infringement. In response, Sanof argued that the patents were invalid under § 112 of the Patent 

Act. That provision requires a patent applicant to describe 

its invention “in such full, clear, concise, and exact terms as 

to enable any person skilled in the art . . . to make and use 

the [invention].” 35 U. S. C. § 112(a). Sanof contended that 

Amgen's patents failed to meet this standard because they 

sought to claim for Amgen's exclusive use potentially millions more antibodies than the company had taught scientists 

to make. In the end, both the district court and Federal 

Circuit sided with Sanof. The question we face is whether 

to disturb their judgment. 

I 

A 

The immune system produces antibodies as a defense to 

foreign agents called antigens. When a particular antigen— 

a virus, for example—enters the body, the immune system 

generates antibodies to attack it. In a successful attack, the 

antibodies target and bind to the antigen, stopping it from 

causing harm to the body. See Brief for Sir Gregory Paul 

Winter et al. as Amici Curiae 8 (Winter Brief); M. Lemley & 

J. Sherkow, The Antibody Patent Paradox, 132 Yale L. J. 994, 

1001–1002 (2023). 

Antibodies are incredibly diverse. Some scientists estimate that there may be as many unique antibodies as there 

are stars in the galaxy. See id., at 1003; see also B. Briney, 

A. Inderbitzin, C. Joyce, & D. Burton, Commonality Despite 

Exceptional Diversity in the Baseline Human Antibody Repertoire, 566 Nature 393, 397 (No. 7744, Feb. 2019) (estimating 

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that the immune system could potentially generate up to a 

quintillion unique antibodies). This diversity shows up in 

both structure and function. 

Start with structure. “When scientists refer to an antibody's `structure,' ” they may have in mind “several related 

concepts,” each of which describes “what an antibody is.” 

Winter Brief 10. Antibodies are made up of amino acids, 

and scientists commonly identify a particular antibody according to its specifc sequence of amino acids—what they 

call an antibody's “ `primary structure.' ” Id., at 9–10. But 

antibodies are not just linear chains of amino acids. As the 

atoms of the amino acids interact with each other, they create folds that result in complex three-dimensional shapes. 

Ibid. Scientists refer to an antibody's intricate topography 

as its “tertiary structure.” Id., at 10. 

An antibody's structure does much to dictate its function— 

its ability to bind to an antigen and, in some instances, to 

block other molecules in the body from doing the same. 

“For an antibody to bind to an antigen, the two surfaces have 

to ft together and contact each other at multiple points.” 

Id., at 11. But just because an antibody can bind to an antigen does not mean that it can also block. To bind and block, 

the antibody must establish a suffciently broad, strong, and 

stable bond to the antigen. See ibid. Different antibodies 

have different binding and blocking capacities based on the 

amino acids that compose them and their three-dimensional 

shapes. See id., at 11–12. 

Despite recent advances, aspects of antibody science remain unpredictable. For example, scientists understand 

that changing even one amino acid in the sequence can alter 

an antibody's structure and function. See id., at 14. But 

scientists cannot always accurately predict exactly how trading one amino acid for another will affect an antibody's structure and function. Ibid. As Amgen's expert testifed at 

trial: “ `[T]he way in which you get from sequence to that 

three-dimensional structure isn't fully understood to-
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day. It's going to get a Nobel Prize for somebody at some 

point, but translating that sequence into a known threedimensional structure is still not possible.' ” Id., at 14–15. 

B 

While the immune system naturally produces an army of 

antibodies to protect us from various harms, scientists are 

now able to engineer antibodies to assist in treating diseases. 

Some of these lab-made antibodies target not foreign agents 

but the body's own proteins, receptors, and ligands. “While 

naturally occurring in our bodies, these [proteins, receptors, 

and ligands] can also be involved in infammatory disorders, 

uncontrolled cell growth, or other biological pathways that 

may be associated with disease.” Id., at 8. 

One part of this effort has focused on the creation of antibodies to treat patients with high LDL cholesterol. A silent 

killer, LDL cholesterol can contribute to the formation of 

plaque in the arteries that may lead to cardiovascular disease, heart attacks, and strokes. For many people with high 

LDL cholesterol, drugs called statins offer an effective treatment. For others, statins do not work well or come with 

unwelcome side effects. In those cases, a relatively new 

antibody-based treatment known as a PCSK9 inhibitor may 

be appropriate. See Amgen Inc. v. Sanofi, 872 F. 3d 1367, 

1371 (CA Fed. 2017). 

PCSK9 is a naturally occurring protein that binds to and 

degrades LDL receptors. That can pose a problem because 

the body produces LDL receptors to perform the benefcial function of extracting LDL cholesterol from the bloodstream. See ibid. Scientists have understood this much 

for some time. But it wasn't until fairly recently that they 

began exploring how antibodies might be used to inhibit 

PCSK9 from binding to and degrading LDL receptors as a 

way to treat patients with high LDL cholesterol. 

In the mid-2000s, a number of pharmaceutical companies 

began looking into the possibility of making antibodies to 

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target PCSK9. See Brief for Respondents 7; Brief for Arnold Ventures et al. as Amici Curiae 17–20. More precisely, 

they sought to create antibodies that could bind to a particular region of PCSK9 called the “sweet spot.” See Brief for 

Petitioners 10–11. The sweet spot is a sequence of 15 amino 

acids out of PCSK9's 692 total amino acids. Id., at 11. By 

binding to the sweet spot, scientists found, an antibody could 

prevent PCSK9 from binding to and degrading LDL receptors. See id., at 10–11; Amgen, 872 F. 3d, at 1371. 

Eventually, Amgen developed a PCSK9-inhibiting drug 

that it marketed under the name Repatha, and Sanofi 

produced one it labeled Praluent. Each drug employs a distinct antibody with its own unique amino acid sequence. 

See id., at 1371–1372; Brief for Respondents 8–10. In 2011, 

Amgen obtained a patent for the antibody employed in Repatha, and Sanof received one covering the antibody used in 

Praluent. See id., at 8, 9. Each patent describes the relevant antibody by its amino acid sequence. See ibid. Neither of these patents is at issue in this case. 

Instead, our dispute focuses on two additional patents 

Amgen obtained in 2014 that relate back to the company's 

2011 patent. See U. S. Patent No. 8,829,165 (Sept. 9, 2014); 

U. S. Patent No. 8,859,741 (Oct. 14, 2014). We refer to them 

as the '165 and '741 patents. In particular, this case revolves around claims 19 and 29 of the '165 patent and claim 

7 of the '741 patent. See 987 F. 3d 1080, 1082 (CA Fed. 

2021). In these claims, Amgen did not seek protection for 

any particular antibody described by amino acid sequence. 

Instead, Amgen purported to claim for itself “the entire 

genus” of antibodies that (1) “bind to specifc amino acid residues on PCSK9,” and (2) “block PCSK9 from binding to 

[LDL receptors].” Amgen, 872 F. 3d, at 1372. 

As part of its submission to the patent offce, Amgen identifed the amino acid sequences of 26 antibodies that perform 

these two functions, and it depicted the three-dimensional 

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structures of two of these 26 antibodies. 987 F. 3d, at 1083. 

But beyond that, Amgen only offered scientists two methods 

to make other antibodies that perform the binding and blocking functions it described. The frst method is what Amgen 

calls the “roadmap.” Brief for Petitioners 13. At a high 

level, the roadmap directs scientists to: (1) generate a range 

of antibodies in the lab; (2) test those antibodies to determine 

whether any bind to PCSK9; (3) test those antibodies that 

bind to PCSK9 to determine whether any bind to the sweet 

spot as described in the claims; and (4) test those antibodies 

that bind to the sweet spot as described in the claims to 

determine whether any block PCSK9 from binding to LDL 

receptors. See id., at 13–14. The second method is what 

Amgen calls “conservative substitution.” Id., at 14, 17. 

This technique requires scientists to: (1) start with an antibody known to perform the described functions; (2) replace 

select amino acids in the antibody with other amino acids 

known to have similar properties; and (3) test the resulting 

antibody to see if it also performs the described functions. 

See id., at 14–15. 

C 

Soon after receiving the '165 and '741 patents, Amgen sued 

Sanof for infringing them. Sanof replied that it was not 

liable to Amgen because the relevant claims were invalid as 

a matter of law. Invalid, Sanof said, because Amgen had 

not enabled a person skilled in the art to make and use all 

of the antibodies that perform the two functions Amgen described in its claims. See 987 F. 3d, at 1083–1085. While 

Amgen had identifed the amino acid sequences of 26 antibodies that bind to PCSK9 and block it from binding to LDL 

receptors, Sanof observed that Amgen's claims cover potentially millions more undisclosed antibodies that perform 

these same functions. And, Sanof argued, neither of the 

two methods Amgen had outlined for generating additional 

antibodies with the same functions enable a person skilled in 

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the art to do so reliably. Instead, Sanof submitted, those 

methods require scientists to engage in little more than a 

trial-and-error process of discovery. See id., at 1085. 

After lengthy proceedings, the district court granted Sanof judgment as a matter of law, concluding that the claims 

at issue “are not enabled.” 2019 WL 4058927, *13 (Del., 

Aug. 28, 2019). The Federal Circuit affrmed. 987 F. 3d, 

at 1088. It determined that “no reasonable factfnder could 

conclude” that Amgen had provided “adequate guidance” to 

make and use the claimed antibodies “beyond the narrow 

scope of the [26] working examples” it had identifed by their 

amino acid sequences. Ibid. In response to Amgen's petition for certiorari, we agreed to take up the case. 598 

U. S. ––– (2022). 

II 

The Constitution vests Congress with the power to “promote the Progress of Science and useful Arts, by securing 

for limited Times to Authors and Inventors the exclusive 

Right to their respective Writings and Discoveries.” Art. 

I, § 8, cl. 8. Right there in the text, one fnds the outline 

of what this Court has called the patent “bargain.” Bonito 

Boats, Inc. v. Thunder Craft Boats, Inc., 489 U. S. 141, 150 

(1989). In exchange for bringing “new designs and technologies into the public domain through disclosure,” so they 

may beneft all, an inventor receives a limited term of “protection from competitive exploitation.” Id., at 151; see also 

The Federalist No. 43, p. 272 (C. Rossiter ed. 1961) (J. Madison) (explaining that in such cases “[t]he public good fully 

coincides . . . with the claims of individuals”). 

Congress has exercised this authority from the start. 

The Patent Act of 1790 promised up to a 14-year monopoly 

to any applicant who “invented or discovered any useful art, 

manufacture, . . . or device, or any improvement therein not 

before known or used.” Act of Apr. 10, 1790, § 1, 1 Stat. 

110. Refecting the quid-pro-quo premise of patent law, the 

statute required the applicant to deposit with the Secretary 

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of State a “specifcation . . . so particular . . . as not only to 

distinguish the invention or discovery from other things before known and used, but also to enable a workman or other 

person skilled in the art or manufacture . . . to make, construct, or use the same.” § 2, ibid. The statute made clear 

that this disclosure would ensure “the public may have the 

full beneft [of the invention or discovery], after the expiration of the patent term.” Ibid. 

Even as Congress has revised the patent laws over time, 

it has left this “enablement” obligation largely intact. See 

35 U. S. C. §§ 111, 112. Section 111 of the current Patent 

Act provides that a patent application “shall include . . . a 

specifcation as prescribed by section 112.” § 111(a)(2)(A). 

Section 112, in turn, requires a specifcation to include “a 

written description of the invention, and of the manner and 

process of making and using it, in such full, clear, concise, 

and exact terms as to enable any person skilled in the art . . . 

to make and use the same.” § 112(a). So today, just as in 

1790, the law secures for the public its beneft of the patent 

bargain by ensuring that, “upon the expiration of [the patent], the knowledge of the invention [i]nures to the people, 

who are thus enabled without restriction to practice it.” 

United States v. Dubilier Condenser Corp., 289 U. S. 178, 

187 (1933); see also Grant v. Raymond, 6 Pet. 218, 247 (1832) 

(Marshall, C. J.) (“This is necessary in order to give the public, after the privilege shall expire, the advantage for which 

the privilege is allowed, and is the foundation of the power 

to issue a patent”); Whittemore v. Cutter, 29 F. Cas. 1120, 

1122 (No. 17,600) (CC Mass. 1813) (Story, J.) (“If therefore 

[the disclosure] be so obscure, loose, and imperfect, that this 

cannot be done, it is defrauding the public of all the consideration, upon which the monopoly is granted”). 

This Court has addressed the enablement requirement on 

many prior occasions. See, e. g., Wood v. Underhill, 5 How. 

1 (1846); O'Reilly v. Morse, 15 How. 62 (1854); The Incandescent Lamp Patent, 159 U. S. 465 (1895); Minerals Separa-
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tion, Ltd. v. Hyde, 242 U. S. 261 (1916); Holland Furniture 

Co. v. Perkins Glue Co., 277 U. S. 245 (1928). While the 

technologies in these older cases may seem a world away 

from the antibody treatments of today, the decisions are no 

less instructive for it. 

Begin with Morse. While crossing the Atlantic Ocean in 

1832 aboard a ship named Sully, Samuel Morse found himself 

in conversation with other passengers about “experiments 

and discoveries” around electromagnetism. 15 How., at 68. 

“In the course of this discussion, it occurred to [Morse] that, 

by means of electricity, signs representing fgures, letters, or 

words, might be legibly written down at any distance.” Id., 

at 69. So clear was the idea in Morse's mind that, “[b]efore 

he landed in the United States, he had . . . drawn out in his 

sketch book . . . the form of an instrument for an electromagnetic telegraph.” Ibid. 

Immediately upon his arrival in New York, Morse showed 

his brothers his sketches. See id., at 69–70. He spent the 

next few years refning his invention. See id., at 70–76. 

The “great diffculty” he faced was that “the galvanic current, however strong in the beginning, became gradually 

weaker as it advanced on the wire[,] and was not strong 

enough to produce a mechanical effect, after a certain distance.” Id., at 107. By 1837, Morse had a solution: “combining two or more electric or galvanic circuits, with independent batteries for the purpose of overcoming the 

diminished force of electro-magnetism in long circuits.” Id., 

at 109. Morse demonstrated his telegraph the following 

year at the Franklin Institute in Philadelphia, and he displayed it soon after in Congress. See id., at 76. He received a patent in 1840, which reissued in 1848. See id., 

at 81–83. 

The litigation that brought Morse before this Court concerned a telegraphic system that Henry O'Reilly had installed between Louisville and Nashville. See id., at 65. 

Morse sued O'Reilly for infringement, alleging that O'Reil-
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ly's system was “identical with” Morse's own. Id., at 66. 

O'Reilly mounted a number of defenses, including that Morse's patent was void because it lacked an adequate specifcation. See id., at 99–101, 112. 

Morse's patent included eight claims, and this Court had 

no trouble upholding seven of them—those limited to the 

telegraphic structures and systems he had designed. See 

id., at 85–86, 112, 117. But the Court paused on the eighth. 

That claim covered “the essence” of the invention, which 

Morse described as “the use of the motive power of the electric or galvanic current . . . however developed for marking 

or printing intelligible characters, signs, or letters, at any 

distances.” Id., at 112 (internal quotation marks omitted). 

Leaving no doubt about this claim's scope, Morse stated 

plainly: “ `I do not propose to limit myself to the specifc machinery or parts of machinery described in the foregoing 

specifcation and claims.' ” Ibid. 

The Court held the eighth claim “too broad, and not warranted by law.” Id., at 113. The problem was that it covered all means of achieving telegraphic communication, yet 

Morse had not described how to make and use them all. See 

id., at 113–117; see also 3 Chisum on Patents § 7.03[1], pp. 7– 

18 to 7–19 (2021). “[I]f the eighth claim . . . can be maintained,” the Court concluded, “there was no necessity for 

any specifcation, further than to say that he had discovered 

that, by using the motive power of electro-magnetism, he 

could print intelligible characters at any distance.” 15 How., 

at 119. “[I]t will be admitted on all hands, that no patent 

could have issued on such a specifcation.” Ibid. 

Consider, too, Incandescent Lamp. For much of the 19th 

century, gas lamps helped illuminate streets and supplemented candles inside homes, factories, offces, and theaters. 

But gas lighting had drawbacks. It took effort to ignite 

lamps each night and extinguish them each morning. Then 

there were the problems of soot and fumes. See R. Stross, 

The Wizard of Menlo Park 84–85 (2007) (Stross). By the 
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1870s, many had experimented with other forms of lighting, 

including incandescence and the arc light. 159 U. S., at 470. 

But these alternatives burned unreliably or with unbearable 

brightness. See id., at 470–471. The latter problem in particular led one observer to lament this “new sort of urban 

star,” which shines “horrible, unearthly, obnoxious” light. 

R. L. Stevenson, A Plea for Gas Lamps, in Virginibus Puerisque and Other Papers 295 (1881). 

Enter Thomas Edison. From his laboratory in Menlo 

Park, Edison and a team toiled to improve upon the prevailing method of incandescent lighting, which tended to employ 

carbon flaments. 159 U. S., at 471–473. The problem with 

carbon flaments was that they disintegrated rapidly. In a 

sense, “carbon contained in itself the elements of its own destruction.” Id., at 471. Seeking an alternative, Edison tinkered for a time with platinum, but it was expensive and 

diffcult to bring to the point of incandescence without melting. Stross 78, 82. Eventually, Edison dispatched men 

across the globe to collect specimens of bamboo. Id., at 109– 

110. One sample from Japan worked brilliantly because 

“[its] fbres [ran] more nearly parallel than in other species 

of wood.” 159 U. S., at 473. Satisfed, Edison arranged to 

have a Japanese farmer supply all of the bamboo he would 

ever need. Stross 110. 

But there was a catch. William Sawyer and Albon Man 

had obtained a patent for an “ `electric lamp' ” with an “ `incandescing conductor' ” made of “ `carbonized fbrous or textile material,' ” which they claimed was an improvement over 

conductors made of “ `mineral or gas carbon.' ” 159 U. S., 

at 466, 468. Sawyer and Man's patent had not won them 

commercial success. They had designed a lamp with a conductor made of carbonized paper, but the lamp proved defective and quickly fell out of use. See id., at 471–472. Still, 

their failure did not stop them from seeking to share in some 

of Edison's success. Sawyer and Man alleged that Edison's 

lamp infringed their patent because it “made use of a fbrous 

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or textile material, covered by the patent.” Id., at 471. 

What was that offending material? Bamboo. 

This Court sided with Edison. It held that Sawyer and 

Man's patent claimed much but enabled little. “Sawyer and 

Man supposed they had discovered in carbonized paper the 

best material for an incandescent conductor.” Id., at 472. 

But “[i]nstead of confning themselves to carbonized paper, 

as they might properly have done, and in fact did in their 

third claim, they made a broad claim for every fbrous or 

textile material.” Ibid. Even that broad claim “might” 

have been permissible, the Court allowed, if Sawyer and 

Man had disclosed “a quality common” to fbrous and textile 

substances that made them “peculiarly” adapted to incandescent lighting. Ibid. Had they done so, others would have 

known how to select among such materials to make an operable lamp. But the record showed that most fbrous and textile materials failed to work. Only through “painstaking experimentation” did Edison discover that bamboo “answered 

the required purpose.” Id., at 475–476. The Court summed up things this way: “[T]he fact that paper happens to 

belong to the fbrous kingdom did not invest [Sawyer and 

Man] with sovereignty over this entire kingdom.” Id., 

at 476. 

The Court returned to these principles in Holland Furniture. There, the evidence indicated that animal glue has 

properties that have long made it excellent for wood veneering. See 277 U. S., at 247. Seeking a substitute, Perkins 

Glue Company had developed and patented a starch glue 

similar enough to animal glue that craftsmen could also use 

it for wood veneering. See ibid. Yet Perkins's patent included a claim that went beyond the specifc starch glue it 

manufactured. See id., at 250–251. This claim covered all 

“starch glue which, [when] combined with about three parts 

or less by weight of water, will have substantially the same 

properties as animal glue.” Id., at 251. Perkins's specifcation instructed gluemakers to choose a “starch ingredient” 

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with “such qualities” that it would yield a product “ `as good 

as animal glue' ” for wood veneering “when combined with 

three parts of water and with alkali.” Id., at 256. 

The Court held this broad claim invalid for lack of enablement. Id., at 258. The specifcation described the key 

input—the “starch ingredient”—in terms of its “use or function” rather than its “physical characteristics or chemical 

properties.” Id., 256. And that left gluemakers in a bind. 

As the Court put it: “One attempting to use or avoid the use 

of Perkins' discovery as so claimed and described functionally could do so only after elaborate experimentation” with 

different starches. Id., at 257. To be sure, the Court held, 

Perkins was entitled to its patent on the specifc starch glue 

it had invented. See id., at 255. The specifcation described that glue's “characteristic ingredient” with “particularity.” Ibid. But just as Morse could not claim all means 

of telegraphic communication, and Sawyer and Man could not 

claim all fbrous and textile materials for incandescence, Perkins could not claim all starch glues made from whatever 

starch happened to perform as well as animal glue. To hold 

otherwise, the Court said, “would extend the monopoly beyond the invention.” Id., at 258. 

Our decisions in Morse, Incandescent Lamp, and Holland 

Furniture reinforce the simple statutory command. If a 

patent claims an entire class of processes, machines, manufactures, or compositions of matter, the patent's specifcation 

must enable a person skilled in the art to make and use the 

entire class. In other words, the specifcation must enable 

the full scope of the invention as defned by its claims. The 

more one claims, the more one must enable. See § 112(a); 

see also Continental Paper Bag Co. v. Eastern Paper Bag 

Co., 210 U. S. 405, 419 (1908) (“[T]he claims measure the 

invention”). 

That is not to say a specifcation always must describe 

with particularity how to make and use every single embodi-
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ment within a claimed class. For instance, it may suffce to 

give an example (or a few examples) if the specifcation also 

discloses “some general quality . . . running through” the 

class that gives it “a peculiar ftness for the particular purpose.” Incandescent Lamp, 159 U. S., at 475. In some 

cases, disclosing that general quality may reliably enable a 

person skilled in the art to make and use all of what is 

claimed, not merely a subset. See id., at 475–476.1 

Nor is a specifcation necessarily inadequate just because 

it leaves the skilled artist to engage in some measure of adaptation or testing. In Wood, a patent claimed a process for 

making bricks by mixing coal dust into clay. 5 How., at 4. 

The patent included “a general rule” about the proportion of 

dust and clay to use and offered two alternative proportions 

“where the clay has some peculiarity.” Id., at 5. The Court 

upheld the claim, recognizing that “some small difference in 

the proportions must occasionally be required” given the varieties of clay. Ibid. Similarly, in Minerals Separation, 

the Court dismissed a challenge to a claimed process for separating metal from mineral ores. 242 U. S., at 270. The 

record showed that “preliminary tests” were required to 

adapt the process to any particular ore. Ibid. Once more, 

the Court explained that “the certainty which the law requires in patents is not greater than is reasonable.” Ibid. 

And because the “composition of ores varies infnitely,” it 

1 See also Béné v. Jeantet, 129 U. S. 683, 684–686 (1889) (rejecting claim 

to method of shrinking coarse hair because the specifcation failed to give 

“one skilled in chemistry such an idea of the particular kinds and character 

of the chemicals, or combination of chemicals, with the relative proportions 

of each, as would enable him to use the invention without having to resort 

to experiments of his own to discover those ingredients”); Corona Cord 

Tire Co. v. Dovan Chemical Corp., 276 U. S. 358, 385 (1928) (rejecting 

claims to process of treating rubber with “ `a disubstituted guanidine' ” 

because “between ffty and one hundred substances” ft that description 

and the specifcation did not disclose “any general quality common to disubstituted guanidines which makes them all effective”). 

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was “impossible to specify in a patent the precise treatment 

which would be most successful and economical in each case.” 

Id., at 271.2 

Decisions such as Wood and Minerals Separation establish 

that a specifcation may call for a reasonable amount of experimentation to make and use a patented invention. What 

is reasonable in any case will depend on the nature of the 

invention and the underlying art. See Minerals Separation, 242 U. S., at 270–271; see also Mowry v. Whitney, 14 

Wall. 620, 644 (1872) (“[T]he defniteness of a specifcation 

must vary with the nature of its subject. Addressed as it is 

to those skilled in the art, it may leave something to their 

skill in applying the invention”). But in allowing that much 

tolerance, courts cannot detract from the basic statutory requirement that a patent's specifcation describe the invention 

“in such full, clear, concise, and exact terms as to enable any 

person skilled in the art” to “make and use” the invention. 

§ 112(a). Judges may no more subtract from the requirements for obtaining a patent that Congress has prescribed 

than they may add to them. See Bilski v. Kappos, 561 U. S. 

593, 602–603, 612 (2010). 

III 

With these principles in mind, we return to claims 19 and 

29 of the '165 patent and claim 7 of the '741 patent. In doing 

so, we do not doubt that Amgen's specifcation enables the 

26 exemplary antibodies it identifes by their amino acid se2 See also, e. g., Ives v. Hamilton, 92 U. S. 426, 429, 432 (1876) (upholding 

claim “for an improvement in sawmills” based on “curved guides at the 

upper end of the saw,” even though the specifcation did not “stat[e] the 

nature of the curve,” because a “good mechanic acquainted with the construction of sawmills, and having the patent and diagram before him, 

would have no diffculty in adopting the improvement, and making suitable 

curves”); Tilghman v. Proctor, 102 U. S. 707, 732–733 (1881) (upholding 

claim for process of separating fats and oils even though the specifcation 

“suggests a trial . . . with different degrees of heat so as to ascertain that 

which is best for each particular kind of fat”). 

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quences. Even Sanof concedes that description is enough 

to allow a person skilled in the art to make and use those 

embodiments. See Tr. of Oral Arg. 68. But the claims before us sweep much broader than those 26 antibodies. And 

we agree with the lower courts that Amgen has failed to 

enable all that it has claimed, even allowing for a reasonable 

degree of experimentation. 

While the technology at the heart of this case is thoroughly modern, from the law's perspective Amgen's claims 

bear more than a passing resemblance to those this Court 

faced long ago in Morse, Incandescent Lamp, and Holland 

Furniture. Amgen seeks to monopolize an entire class of 

things defned by their function—every antibody that both 

binds to particular areas of the sweet spot of PCSK9 and 

blocks PCSK9 from binding to LDL receptors. The record 

refects that this class of antibodies does not include just the 

26 that Amgen has described by their amino acid sequences, 

but a “vast” number of additional antibodies that it has not. 

987 F. 3d, at 1085, 1088; see 2019 WL 4058927, *8 (“at least 

millions of candidates”); see also Tr. of Oral Arg. 52–53. 

Much as Morse sought to claim all telegraphic forms of communication, Sawyer and Man sought to claim all fbrous and 

textile materials for incandescence, and Perkins sought to 

claim all starch glues that work as well as animal glue for 

wood veneering, Amgen seeks to claim “sovereignty over 

[an] entire kingdom” of antibodies. Incandescent Lamp, 159 

U. S., at 476. 

That poses Amgen with a challenge. For if our cases 

teach anything, it is that the more a party claims, the 

broader the monopoly it demands, the more it must enable. 

That holds true whether the case involves telegraphs devised 

in the 19th century, glues invented in the 20th, or antibody 

treatments developed in the 21st. To be fair, Amgen does 

not dispute this much. It freely admits that it seeks to claim 

for itself an entire universe of antibodies. Still, it says, its 

broad claims are enabled because scientists can make and 
614 AMGEN INC. v. SANOFI 

Opinion of the Court 

use every undisclosed but functional antibody if they simply 

follow the company's “roadmap” or its proposal for “conservative substitution.” 

We cannot agree. These two approaches amount to little 

more than two research assignments. The frst merely describes step-by-step Amgen's own trial-and-error method for 

fnding functional antibodies—calling on scientists to create 

a wide range of candidate antibodies and then screen each to 

see which happen to bind to PCSK9 in the right place and 

block it from binding to LDL receptors. See Part I–B, 

supra; 987 F. 3d, at 1088; 2019 WL 4058927, *10–*13. The 

second isn't much different. It requires scientists to make 

substitutions to the amino acid sequences of antibodies 

known to work and then test the resulting antibodies to see 

if they do too—an uncertain prospect given the state of 

the art. See Parts I–A, I–B, supra; 987 F. 3d, at 1088; 2019 

WL 4058927, *10–*13. Whether methods like a “roadmap” 

or “conservative substitution” might suffce to enable other 

claims in other patents—perhaps because, as this Court 

suggested in Incandescent Lamp, the inventor identifes a 

quality common to every functional embodiment, supra, at 

609—they do not here. They leave a scientist about where 

Sawyer and Man left Edison: forced to engage in “painstaking experimentation” to see what works. 159 U. S., at 475. 

That is not enablement. More nearly, it is “a hunting license.” Brenner v. Manson, 383 U. S. 519, 536 (1966). 

Think about it this way. “Imagine a combination lock 

with 100 tumblers, each of which can be set to 20 different 

positions.” Brief for Intellectual Property Law Professors 

and Scholars as Amici Curiae 20. “Through trial and error, 

imagine that an inventor fnds and discloses 26 different successful lock combinations.” Ibid. But imagine, too, “that 

the inventor tries to claim much more, namely all successful 

combinations,” while instructing others “to randomly try a 

large set of combinations and then record the successful 

ones.” Id., at 20–21. Sure enough, that kind of “roadmap” 

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would produce functional combinations. Id., at 21. But it 

would not enable others to make and use functional combinations; it would instead leave them to “random trial-and-error 

discovery.” Ibid. Like many analogies, this one may oversimplify a bit, but it captures the gist of the problem. 

Failing in its primary argument that it has enabled all of 

the antibodies it claims, Amgen tries a few alternative lines 

of attack. First, it suggests that the Federal Circuit erred 

by applying an enablement test unmoored from the statutory 

text. As Amgen sees it, that court confated the question 

whether an invention is enabled with the question how long 

may it take a person skilled in the art to make every embodiment within a broad claim. See Brief for Petitioners 24–29; 

see also id., at 2, 19–20, 30–36. We do not see it that way. 

While we agree with Amgen that enablement is not measured against the cumulative time and effort it takes to make 

every embodiment within a claim, we are not so sure the 

Federal Circuit thought otherwise. That court went out of 

its way to say that it “do[es] not hold that the effort required 

to exhaust a genus is dispositive.” 987 F. 3d, at 1088 (emphasis deleted). Instead, the court stressed, the problem 

it saw is the same problem we see: Amgen offers persons 

skilled in the art little more than advice to engage in “trial 

and error.” Ibid. (internal quotation marks omitted). In 

any event, we review judgments of the lower courts, not 

statements in their opinions. See Black v. Cutter Laboratories, 351 U. S. 292, 297 (1956). 

Taking a similar tack, Amgen next argues that the Federal 

Circuit erroneously “raise[d] the bar” for enablement of 

claims that, like Amgen's, encompass an entire “genus” of 

embodiments defned by their function. Brief for Petitioners 25 (internal quotation marks omitted). This is impermissible, Amgen argues, because the Patent Act “provides a 

single, universal enablement standard for all invention[s].” 

Ibid. (internal quotation marks omitted). Here, too, we 

agree with Amgen in principle: There is one statutory en-
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ablement standard. But, once more, we do not understand 

the Federal Circuit to have thought differently. Instead, we 

understand that court to have recognized only that the more 

a party claims for itself the more it must enable. As we 

have seen, that much is entirely consistent with Congress's 

directive and this Court's precedents. 

Finally, Amgen warns that an affrmance risks “destroy-

[ing] incentives for breakthrough inventions.” Id., at 38. 

But striking the proper balance between incentivizing inventors and ensuring the public receives the full beneft of their 

innovations is a policy judgment that belongs to Congress. 

Since 1790, Congress has included an enablement mandate 

as one feature among many designed to achieve the balance 

it wishes. Our only duty in this case lies in applying that 

mandate faithfully. 

* 

Section 112 of the Patent Act refects Congress's judgment 

that if an inventor claims a lot, but enables only a little, the 

public does not receive its beneft of the bargain. For more 

than 150 years, this Court has enforced the statutory enablement requirement according to its terms. If the Court had 

not done so in Incandescent Lamp, it might have been writing decisions like Holland Furniture in the dark. Today's 

case may involve a new technology, but the legal principle is 

the same. The judgment is 

Affrmed. 
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Reporter’s Note 

The attached opinion has been revised to refect the usual publication 

and citation style of the United States Reports. The revised pagination 

makes available the offcial United States Reports citation in advance of 

publication. The syllabus has been prepared by the Reporter of Decisions 

for the convenience of the reader and constitutes no part of the opinion of 

the Court. A list of counsel who argued or fled briefs in this case, and 

who were members of the bar of this Court at the time this case was 

argued, has been inserted following the syllabus. Other revisions may 

include adjustments to formatting, captions, citation form, and any errant 

punctuation. The following additional edits were made: 

p. 597, line 14, “10 F. 4th 1016” is replaced with “987 F. 3d 1080” 

p. 609, line 9, “and” is replaced with “or”