Amgen Inc. v. Sanofi

P R E L I M I N A R Y P R I N T
Volume 598 U. S. Part 2
Pages 594–616
OFFICIAL REPORTS
OF
T H E S U P R E M E C O U R T
May 18, 2023
REBECCA A. WOMELDORF
reporter of decisions
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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 blood-
stream. Two pharmaceutical companies—Amgen and Sanof—each de-
veloped 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 anti-
body by its unique amino acid sequence. The dispute in this case con-
cerns 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 spe-
cifc 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 an-
tibodies that perform the binding-and-blocking functions described in
the claims.
After Amgen obtained the 2014 patents, it sued Sanof for infringe-
ment. 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 [inven-
tion].” 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 Am-
gen's patents failed to meet the enablement requirement because they
sought to claim for Amgen's exclusive use potentially millions more anti-
bodies 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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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 competi-
tive exploitation” in exchange for bringing “new designs and technolo-
gies 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 manu-
facture . . . 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 composi-
tions 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 tele-
graphic 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 confn-
ing their claim to carbonized paper, “made a broad claim for every f-
brous 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,

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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 particu-
larity how to make and use every single embodiment within a claimed
class. It may suffce to give an example if the specifcation also dis-
closes “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 be-
cause it leaves the skilled artist to engage in some measure of adapta-
tion or testing. See, e. g., Wood v. Underhill, 5 How. 1, 4–5. A specif-
cation 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 recep-
tors—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 scien-
tists 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, “conserv-
ative 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 anti-
bodies. Amgen next argues that the Patent Act supplies a single, uni-
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Syllabus
versal enablement standard, while the Federal Circuit applied a higher
st
andard to Amgen's claims that encompass an entire genus of embodi-
ments 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 in-
ventions, 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,
Dan i el L. Re isne r, Debo rah Fishm an, and Vi ct o r i a 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 Gen-
eral 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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Justice Gorsuch delivered the opinion of the Court.
T
he development of antibody dr ugs has y ielded l ife-
changing 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 anti-
bodies that help reduce levels of low-density lipoprotein cho-
lesterol, sometimes called LDL cholesterol (for the obvious
reason) or bad cholesterol (because it can lead to cardiovas-
cular disease, heart attacks, and strokes).
and Innovators by Jeffrey P. Kushan, Joshua J. Fougere, Matthew Maho-
ney, 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 Prop-
erty 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 Prop-
erty 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 Dimi-
trios 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 Intellec-
tual Property Owners Association by Vanessa Yen and Evan Diamond.

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Opinion of the Court
The case comes to us this way. Several years ago, peti-
ti
oners (Amgen) obtained two patents. Together, these pat-
ents 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 blood-
stream. Soon after receiving these patents, Amgen sued re-
spondents (Sanof) for infringement. In response, Sanof ar-
gued 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 mil-
lions 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 esti-
mate 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 Rep-
ertoire, 566 Nature 393, 397 (No. 7744, Feb. 2019) (estimating
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that the immune system could potentially generate up to a
qui
ntillion unique antibodies). This diversity shows up in
both structure and function.
Start with structure. “When scientists refer to an anti-
body'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 ac-
cording 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 cre-
ate 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 anti-
gen 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 re-
main 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 trad-
ing one amino acid for another will affect an antibody's struc-
ture and function. Ibid. As Amgen's expert testifed at
trial: “ `[T]he way in which you get from sequence to that
three-di mensi ona l str uc ture isn't fu l ly understood to-

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day. It's going to get a Nobel Prize for somebody at some
poi
nt, but translating that sequence into a known three-
dimensional 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 anti-
bodies 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 dis-
ease, heart attacks, and strokes. For many people with high
LDL cholesterol, drugs called statins offer an effective treat-
ment. 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 benef-
cial function of extracting LDL cholesterol from the blood-
stream. 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 Ar-
nold
Ventures et al. as Amici Curiae 17–20. More precisely,
they sought to create antibodies that could bind to a particu-
lar 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 recep-
tors. 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 dis-
tinct 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 Repa-
tha, and Sanof received one covering the antibody used in
Praluent. See id., at 8, 9. Each patent describes the rele-
vant antibody by its amino acid sequence. See ibid. Nei-
ther 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 re-
volves 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 resi-
dues 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 iden-
tifed 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 block-
ing 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 anti-
body 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 de-
scribed in its claims. See 987 F. 3d, at 1083–1085. While
Amgen had identifed the amino acid sequences of 26 antibod-
ies that bind to PCSK9 and block it from binding to LDL
receptors, Sanof observed that Amgen's claims cover po-
tentially 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 Sa-
nof 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 peti-
tion for certiorari, we agreed to take up the case. 598
U. S. ––– (2022).
II
The Constitution vests Congress with the power to “pro-
mote 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 technol-
ogies into the public domain through disclosure,” so they
may beneft all, an inventor receives a limited term of “pro-
tection from competitive exploitation.” Id., at 151; see also
The Federalist No. 43, p. 272 (C. Rossiter ed. 1961) (J. Madi-
son) (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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Opinion of the Court
of State a “specifcation . . . so particular . . . as not only to
disti
nguish the invention or discovery from other things be-
fore known and used, but also to enable a workman or other
person skilled in the art or manufacture . . . to make, con-
struct, 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 expira-
tion 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 pat-
ent], 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 pub-
lic, 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 consider-
ation, 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 Incandes-
cent Lamp Patent, 159 U. S. 465 (1895); Minerals Separa-

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606 AMGEN
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tion, Ltd. v. Hyde, 242 U. S. 261 (1916); Holland Furniture
C
o. 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 electro-
magnetic 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 cur-
rent, 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 dis-
tance.” Id., at 107. By 1837, Morse had a solution: “com-
bining two or more electric or galvanic circuits, with in-
dependent batter ies 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 dis-
played it soon after in Congress. See id., at 76. He re-
ceived a patent in 1840, which reissued in 1848. See id.,
at 81–83.
The litigation that brought Morse before this Court con-
cerned a telegraphic system that Henry O'Reilly had in-
stalled 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'Rei
lly mounted a number of defenses, including that Mor-
se's patent was void because it lacked an adequate specifca-
tion. 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 elec-
tric 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 ma-
chinery or parts of machinery described in the foregoing
specifcation and claims.' ” Ibid.
The Court held the eighth claim “too broad, and not war-
ranted by law.” Id., at 113. The problem was that it cov-
ered 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 main-
tained,” 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 supple-
mented 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,
i
ncluding 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 par-
ticular 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 Pueris-
que and Other Papers 295 (1881).
Enter Thomas Edison. From his laboratory in Menlo
Park, Edison and a team toiled to improve upon the prevail-
ing 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 de-
struction.” Id., at 471. Seeking an alternative, Edison tin-
kered for a time with platinum, but it was expensive and
diffcult to bring to the point of incandescence without melt-
ing. 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 “ `in-
candescing conductor' ” made of “ `carbonized fbrous or tex-
tile 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 con-
ductor made of carbonized paper, but the lamp proved defec-
tive 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.
W
hat 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 incandes-
cent lighting. Ibid. Had they done so, others would have
known how to select among such materials to make an opera-
ble lamp. But the record showed that most fbrous and tex-
tile materials failed to work. Only through “painstaking ex-
perimentation” did Edison discover that bamboo “answered
the required purpose.” Id., at 475–476. The Court sum-
med up things this way: “[T]he fact that paper happens to
belong to the fbrous kingdom did not invest [Sawyer and
Man] with sovereig nty over this entire k ingdom. ” Id.,
at 476.
The Court returned to these principles in Holland Furni-
ture. There, the evidence indicated that animal glue has
properties that have long made it excellent for wood veneer-
ing. 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 in-
cluded 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 specif-
cation 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 en-
ablement. Id., at 258. The specifcation described the key
input—the “starch ingredient”—in terms of its “use or func-
tion” 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 function-
ally 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 de-
scribed that glue's “characteristic ingredient” with “particu-
larity.” 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, Per-
kins 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 be-
yond 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, manu-
factures, 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
g
ive 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 pur-
pose.” 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 ad-
aptation 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 va-
rieties of clay. Ibid. Similarly, in Minerals Separation,
the Court dismissed a challenge to a claimed process for sep-
arating 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 re-
quires 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 di-
substituted guanidines which makes them all effective”).
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was “impossible to specify in a patent the precise treatment
wh
ich 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 ex-
perimentation 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 Separa-
tion, 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 re-
quirement 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 require-
ments 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 se-
2
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 con-
struction 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 be-
fore 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 thor-
oughly 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 com-
munication, 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 anyth i ng, it is that the more a par ty clai ms, 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
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use every undisclosed but functional antibody if they simply
fol
low the company's “roadmap” or its proposal for “conserv-
ative substitution.”
We cannot agree. These two approaches amount to little
more than two research assignments. The frst merely de-
scribes 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
substituti ons 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 “painstak-
ing experimentation” to see what works. 159 U. S., at 475.
That is not enablement. More nearly, it is “a hunting li-
cense.” 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 suc-
cessful 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
wou
ld not enable others to make and use functional combina-
tions; it would instead leave them to “random trial-and-error
discovery.” Ibid. Like many analogies, this one may over-
simplify 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 embodi-
ment 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 meas-
ured 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 (em-
phasis 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 Labora-
tories, 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 Petition-
ers 25 (internal quotation marks omitted). This is imper-
missible, 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 inven-
tors 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 enable-
ment requirement according to its terms. If the Court had
not done so in Incandescent Lamp, it might have been writ-
ing 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”