(Slip Opinion)              OCTOBER TERM, 2022                                       1

                                       Syllabus

         NOTE: Where it is feasible, a syllabus (headnote) will be released, as is
       being done in connection with this case, at the time the opinion is issued.
       The syllabus constitutes no part of the opinion of the Court but has been
       prepared by the Reporter of Decisions for the convenience of the reader.
       See United States v. Detroit Timber & Lumber Co., 

.


SUPREME COURT OF THE UNITED STATES

                                       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 Sanofi—each
  developed a PCSK9-inhibiting drug. In 2011, Amgen obtained a pa-
  tent for the antibody employed in its drug, and Sanofi received one
  covering the antibody used in its drug. Each patent describes the rel-
  evant antibody by its unique amino acid sequence. The dispute in this
  case concerns two additional patents Amgen obtained in 2014 that re-
  late 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 specific amino acid residues on PCSK9,” and (2) “block
  PCSK9 from binding to [LDL receptors].” 

. As
  part of its submission to the patent office, Amgen identified 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 Sanofi for infringe-
  ment. Sanofi 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
2                        AMGEN INC. v. SANOFI

                                  Syllabus

    as to enable any person skilled in the art . . . to make and use the [in-
    vention].” 

(a). Sanofi characterized the methods
    Amgen outlined for generating additional antibodies as amounting to
    little more than a trial-and-error process of discovery, and thus con-
    tended that Amgen’s patents failed to meet the enablement require-
    ment because they sought to claim for Amgen’s exclusive use poten-
    tially millions more antibodies than the company had taught persons
    skilled in the art to make. Both the district court and the Federal Cir-
    cuit sided with Sanofi.
Held: The courts below correctly concluded that Amgen failed “to enable
 any person skilled in the art . . . to make and use the [invention]” as
 defined by the relevant claims. Pp. 7–19.
    (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 benefit of all.
 Bonito Boats, Inc. v. Thunder Craft Boats, Inc., 

.
 From the Patent Act’s beginnings, Congress has sought to ensure the
 benefit of this bargain for the public by requiring the patent applicant
 to deposit a “specification . . . so particular . . . as not only to distin-
 guish 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.” 

.
 Over time, Congress has left this “enablement” obligation largely in-
 tact.
    This Court has addressed the enablement requirement many times,
 and its decisions in O’Reilly v. Morse, 

, The Incandescent
 Lamp Patent, 

, and Holland Furniture Co. v. Perkins Glue
 Co., 

, reinforce the simple statutory command: If a patent
 claims an entire class of processes, machines, manufactures, or com-
 positions of matter, the patent’s specification must enable a person
 skilled in the art to make and use the entire class. In Morse, for ex-
 ample, the Court held that one of the claims in Morse’s patent for a
 telegraphic system was “too broad, and not warranted by law.” 

. The problem was that the claim covered all means of
 achieving telegraphic communication, yet Morse’s specification did not
 describe how to make or use them all. See 

 at 113–117. In Incan-
 descent 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 confining their claim to carbonized paper, “made a broad
 claim for every fibrous and textile material.” 

. That
 broad claim “might” have been permissible, the Court allowed, if the
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                              Syllabus

inventors had disclosed “a quality common” to fibrous and textile sub-
stances that made them “peculiarly” adapted to incandescent lighting,
but they did not. 

 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.”

. The specification described the key input—the
“starch ingredient”—in terms of its “use or function” rather than its
“physical characteristics or chemical properties.” 

. The
problem, as the Court put it, 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. 

.
   All this is not to say a specification always must describe with par-
ticularity how to make and use every single embodiment within a
claimed class. It may suffice to give an example if the specification
also discloses “some general quality . . . running through” the class
that gives it “a peculiar fitness for the particular purpose.” Incandes-
cent Lamp, 

. Nor is a specification necessarily inade-
quate just because it leaves the skilled artist to engage in some meas-
ure of adaptation or testing. See, e.g., Wood v. Underhill, 

, 4–
5. A specification 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, 

, 270–271. Pp. 7–15.
   (b) Turning to the patent claims at issue in this case, Amgen’s claims
sweep much broader than the 26 exemplary antibodies it identifies 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 defined 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 reflects 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 sci-
entists can make and use every functional antibody if they simply fol-
low the “roadmap” or “conservative substitution.” These two ap-
proaches, however, amount to little more than two research
assignments. The “roadmap” merely describes step-by-step Amgen’s
own trial-and-error method for finding functional antibodies. Not
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                                  Syllabus

    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 conflating 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,
    universal enablement standard, while the Federal Circuit applied a
    higher standard to Amgen’s claims that encompass an entire genus of
    embodiments defined by their function. The Court agrees in principle
    that there is one statutory enablement standard, but the Federal Cir-
    cuit’s treatment in this case is entirely consistent with Congress’s di-
    rective and this Court’s precedents. Finally, while Amgen warns that
    a ruling against it risks destroying the incentives that lead to break-
    through 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 benefit of their innovations. In this case, the
    Court’s duty is to enforce the statutory enablement requirement ac-
    cording to its terms. Pp. 15–19.

, affirmed.

    GORSUCH, J., delivered the opinion for a unanimous Court.
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                             Opinion of the Court

     NOTICE: This opinion is subject to formal revision before publication in the
     United States Reports. Readers are requested to notify the Reporter of
     Decisions, Supreme Court of the United States, Washington, D. C. 20543,
     [email protected], of any typographical or other formal errors.


SUPREME COURT OF THE UNITED STATES
                                   _________________

                                   No. 21–757
                                   _________________


AMGEN INC., ET AL., PETITIONERS v. SANOFI, ET AL.
 ON WRIT OF CERTIORARI TO THE UNITED STATES COURT OF
           APPEALS FOR THE FEDERAL CIRCUIT
                                 [May 18, 2023]

   JUSTICE GORSUCH delivered the opinion of the Court.
   The development of antibody drugs has yielded life-
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 an-
tibodies that help reduce levels of low-density lipoprotein
cholesterol, sometimes called LDL cholesterol (for the obvi-
ous reason) or bad cholesterol (because it can lead to cardi-
ovascular disease, heart attacks, and strokes).
   The case comes to us this way. Several years ago, peti-
tioners (Amgen) obtained two patents. Together, these pa-
tents claim a monopoly over all antibodies that (1) bind to
specific 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 (Sanofi) for infringement. In response, Sanofi 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].” 

(a). Sanofi contended that
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                      Opinion of the Court

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 scien-
tists to make. In the end, both the district court and Fed-
eral Circuit sided with Sanofi. 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 anti-
gen—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, stop-
ping 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 Par-
adox, 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 

; 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) (es-
timating that the immune system could potentially gener-
ate up to a quintillion 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 specific sequence of amino acids—what they
call an antibody’s “ ‘primary structure.’ ” 

 at 9–10. But
antibodies are not just linear chains of amino acids. As the
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                     Opinion of the Court

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

 Scientists refer to an antibody’s intricate topography
as its “tertiary structure.” 

.
   An antibody’s structure does much to dictate its func-
tion—its ability to bind to an antigen and, in some in-
stances, to block other molecules in the body from doing the
same. “For an antibody to bind to an antigen, the two sur-
faces have to fit together and contact each other at multiple
points.” 

. 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 sufficiently broad,
strong, and stable bond to the antigen. See 

 Different
antibodies have different binding and blocking capacities
based on the amino acids that compose them and their
three-dimensional shapes. See 

 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 

. But
scientists cannot always accurately predict exactly how
trading one amino acid for another will affect an antibody’s
structure and function. 

 As Amgen’s expert testified
at trial: “ ‘[T]he way in which you get from sequence to
that three-dimensional structure isn’t fully understood to-
day. It’s going to get a Nobel Prize for somebody at some
point, but translating that sequence into a known three-di-
mensional structure is still not possible.’ ” 

 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 dis-
eases. 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,
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                     Opinion of the Court

receptors, and ligands] can also be involved in inflamma-
tory disorders, uncontrolled cell growth, or other biological
pathways that may be associated with disease.” 

.
   One part of this effort has focused on the creation of an-
tibodies to treat patients with high LDL cholesterol. A si-
lent 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, 

 (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 beneficial
function of extracting LDL cholesterol from the blood-
stream. See 

 Scientists have understood this much for
some time. But it wasn’t until fairly recently that they be-
gan 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
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 partic-
ular 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, 

.
   Eventually, Amgen developed a PCSK9-inhibiting drug
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                      Opinion of the Court

that it marketed under the name Repatha, and Sanofi pro-
duced one it labeled Praluent. Each drug employs a distinct
antibody with its own unique amino acid sequence. See 

at 1371–1372; Brief for Respondents 8–10. In 2011, Amgen
obtained a patent for the antibody employed in Repatha,
and Sanofi received one covering the antibody used in
Praluent. See 

. Each patent describes the rele-
vant antibody by its amino acid sequence. See 

 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 

 (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 ge-
nus” of antibodies that (1) “bind to specific amino acid resi-
dues on PCSK9,” and (2) “block PCSK9 from binding to
[LDL receptors].” Amgen, 

.
   As part of its submission to the patent office, Amgen iden-
tified the amino acid sequences of 26 antibodies that perform
these two functions, and it depicted the three-dimensional
structures of two of these 26 antibodies. 

.
But beyond that, Amgen only offered scientists two meth-
ods to make other antibodies that perform the binding and
blocking functions it described. The first 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 anti-
bodies 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
6                  AMGEN INC. v. SANOFI

                      Opinion of the Court

the claims to determine whether any block PCSK9 from
binding to LDL receptors. See 

 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 Sanofi for infringing them. Sanofi replied that it was
not liable to Amgen because the relevant claims were inva-
lid as a matter of law. Invalid, Sanofi 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 identified the amino acid sequences of 26 anti-
bodies that bind to PCSK9 and block it from binding to LDL
receptors, Sanofi observed that Amgen’s claims cover poten-
tially millions more undisclosed antibodies that perform
these same functions. And, Sanofi argued, neither of the
two methods Amgen had outlined for generating additional
antibodies with the same functions enable a person skilled
in the art to do so reliably. Instead, Sanofi 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
Sanofi judgment as a matter of law, concluding that the
claims at issue “are not enabled.” 

, *13
(Del., Aug. 28, 2019). The Federal Circuit affirmed. 

. It determined that “no reasonable factfinder
could conclude” that Amgen had provided “adequate guid-
ance” to make and use the claimed antibodies “beyond the
narrow scope of the [26] working examples” it had identified
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                        Opinion of the Court

by their amino acid sequences. 

 In response to
Amgen’s petition for certiorari, we agreed to take up the
case. 

 (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 finds the outline of
what this Court has called the patent “bargain.” Bonito
Boats, Inc. v. Thunder Craft Boats, Inc., 

(1989). In exchange for bringing “new designs and technol-
ogies into the public domain through disclosure,” so they
may benefit all, an inventor receives a limited term of “pro-
tection from competitive exploitation.” 

; see also
The Federalist No. 43, p. 272 (C. Rossiter ed. 1961) (J. Mad-
ison) (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, 

.
Reflecting the quid-pro-quo premise of patent law, the stat-
ute required the applicant to deposit with the Secretary of
State a “specification . . . so particular . . . as not only to dis-
tinguish the invention or discovery from other things before
known and used, but also to enable a workman or other per-
son 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 ben-
efit [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
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                      Opinion of the Court

, 112. Section 111 of the current Patent
Act provides that a patent application “shall include . . . a
specification as prescribed by section 112.” §111(a)(2)(A).
Section 112, in turn, requires a specification 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 benefit 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., 

 (1933); see also Grant v. Raymond, 

(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, 

 (No. 17,600) (CC Mass. 1813) (Story, J.)
(“If therefore [the disclosure] be so obscure, loose, and im-
perfect, 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, 

 (1846); O’Reilly v. Morse, 

 (1854); The
Incandescent Lamp Patent, 

 (1895); Minerals
Separation, Ltd. v. Hyde, 

 (1916); Holland
Furniture Co. v. Perkins Glue Co., 

 (1928).
While the technologies in these older cases may seem a
world away from the antibody treatments of today, the de-
cisions are no less instructive for it.
   Begin with Morse. While crossing the Atlantic Ocean in
1832 aboard a ship named Sully, Samuel Morse found him-
self in conversation with other passengers about “experi-
ments and discoveries” around electromagnetism. 15 How.,
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                      Opinion of the Court

at 68. “In the course of this discussion, it occurred to
[Morse] that, by means of electricity, signs representing fig-
ures, letters, or words, might be legibly written down at any
distance.” 

. 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.” 

   Immediately upon his arrival in New York, Morse showed
his brothers his sketches. See 

 at 69–70. He spent the
next few years refining his invention. See 

 at 70–76.
The “great difficulty” 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.” 

. By 1837, Morse had a solution: “com-
bining two or more electric or galvanic circuits, with inde-
pendent batteries for the purpose of overcoming the
diminished force of electro-magnetism in long circuits.” 

. Morse demonstrated his telegraph the following
year at the Franklin Institute in Philadelphia, and he dis-
played it soon after in Congress. See 

. He received
a patent in 1840, which reissued in 1848. See 

 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 

.
Morse sued O’Reilly for infringement, alleging that
O’Reilly’s system was “identical with” Morse’s own. 

. O’Reilly mounted a number of defenses, including that
Morse’s patent was void because it lacked an adequate spec-
ification. See 

 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

 at 85–86, 112, 117. But the Court paused on the eighth.
That claim covered “the essence” of the invention, which
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                      Opinion of the Court

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.” 

 (internal quotation marks omitted).
Leaving no doubt about this claim’s scope, Morse stated
plainly: “ ‘I do not propose to limit myself to the specific
machinery or parts of machinery described in the foregoing
specification and claims.’ ” 

   The Court held the eighth claim “too broad, and not war-
ranted by law.” 

. 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

 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 specification, further than to say that he had discov-
ered that, by using the motive power of electro-magnetism,
he could print intelligible characters at any distance.” 

. “[I]t will be admitted on all hands, that no
patent could have issued on such a specification.” 

   Consider, too, Incandescent Lamp. For much of the 19th
century, gas lamps helped illuminate streets and supple-
mented candles inside homes, factories, offices, and thea-
ters. But gas lighting had drawbacks. It took effort to ig-
nite 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 1870s, many had experimented with other forms of
lighting, including incandescence and the arc light. 

. But these alternatives burned unreliably or
with unbearable brightness. See 

 at 470–471. The latter
problem in particular led one observer to lament this “new
sort of urban star,” which shines “horrible, unearthly, ob-
noxious” 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
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Park, Edison and a team toiled to improve upon the prevail-
ing method of incandescent lighting, which tended to em-
ploy carbon filaments. 159 U. S., at 471–473. The problem
with carbon filaments was that they disintegrated rapidly.
In a sense, “carbon contained in itself the elements of its
own destruction.” 

. Seeking an alternative, Edi-
son tinkered for a time with platinum, but it was expensive
and difficult to bring to the point of incandescence without
melting. Stross 78, 82. Eventually, Edison dispatched men
across the globe to collect specimens of bamboo. 

 at 109–
110. One sample from Japan worked brilliantly because
“[its] fibres [ran] more nearly parallel than in other species
of wood.” 

. Satisfied, 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 fibrous or tex-
tile material,’ ” which they claimed was an improvement
over conductors made of “ ‘mineral or gas carbon.’ ” 

. 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 

 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 fibrous or textile material, covered by the patent.” 

. 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.” 

.
But “[i]nstead of confining 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 fibrous and
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                      Opinion of the Court

textile material.” 

 Even that broad claim “might” have
been permissible, the Court allowed, if Sawyer and Man
had disclosed “a quality common” to fibrous and textile sub-
stances that made them “peculiarly” adapted to incandes-
cent lighting. 

 Had they done so, others would have
known how to select among such materials to make an op-
erable lamp. But the record showed that most fibrous and
textile materials failed to work. Only through “painstaking
experimentation” did Edison discover that bamboo “an-
swered the required purpose.” 

 at 475–476. The Court
summed up things this way: “[T]he fact that paper happens
to belong to the fibrous kingdom did not invest [Sawyer and
Man] with sovereignty over this entire kingdom.” 

.
   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 

. 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 

 Yet Perkins’s patent in-
cluded a claim that went beyond the specific starch glue it
manufactured. See 

 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.” 

. Perkins’s specifica-
tion instructed gluemakers to choose a “starch ingredient”
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.” 

.
   The Court held this broad claim invalid for lack of ena-
blement. 

. The specification described the key
input—the “starch ingredient”—in terms of its “use or func-
tion” rather than its “physical characteristics or chemical
properties.” 

. And that left gluemakers in a bind.
As the Court put it: “One attempting to use or avoid the
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                      Opinion of the Court

use of Perkins’ discovery as so claimed and described func-
tionally could do so only after elaborate experimentation”
with different starches. 

. To be sure, the Court
held, Perkins was entitled to its patent on the specific
starch glue it had invented. See 

. The specifica-
tion described that glue’s “characteristic ingredient” with
“particularity.” 

 But just as Morse could not claim all
means of telegraphic communication, and Sawyer and Man
could not claim all fibrous and textile materials for incan-
descence, Perkins could not claim all starch glues made
from whatever starch happened to perform as well as ani-
mal glue. To hold otherwise, the Court said, “would extend
the monopoly beyond the invention.” 

.
   Our decisions in Morse, Incandescent Lamp, and Holland
Furniture reinforce the simple statutory command. If a pa-
tent claims an entire class of processes, machines, manu-
factures, or compositions of matter, the patent’s specifica-
tion must enable a person skilled in the art to make and use
the entire class. In other words, the specification must en-
able the full scope of the invention as defined by its claims.
The more one claims, the more one must enable. See
§112(a); see also Continental Paper Bag Co. v. Eastern Pa-
per Bag Co., 

 (1908) (“[T]he claims meas-
ure the invention.”).
   That is not to say a specification always must describe
with particularity how to make and use every single embod-
iment within a claimed class. For instance, it may suffice
to give an example (or a few examples) if the specification
also discloses “some general quality . . . running through”
the class that gives it “a peculiar fitness for the particular
purpose.” Incandescent Lamp, 

. In some
cases, disclosing that general quality may reliably enable a
person skilled in the art to make and use all of what is
14                      AMGEN INC. v. SANOFI

                           Opinion of the Court

claimed, not merely a subset. See 

 at 475–476.1
   Nor is a specification 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. 

.
The patent included “a general rule” about the proportion
of dust and clay to use and offered two alternative propor-
tions “where the clay has some peculiarity.” 

. The
Court upheld the claim, recognizing that “some small dif-
ference in the proportions must occasionally be required”
given the varieties of clay. 

 Similarly, in Minerals Sep-
aration, the Court dismissed a challenge to a claimed pro-
cess for separating metal from mineral ores. 

. The record showed that “preliminary tests” were re-
quired to adapt the process to any particular ore. 

Once more, the Court explained that “the certainty which
the law requires in patents is not greater than is reasona-
ble.” 

 And because the “composition of ores varies in-
finitely,” it was “impossible to specify in a patent the precise
treatment which would be most successful and economical
in each case.” 

.2

——————
  1 See also Béné v. Jeantet, 

, 684–686 (1889) (rejecting

claim to method of shrinking coarse hair because the specification 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., 

 (1928)
(rejecting claims to process of treating rubber with “ ‘a disubstituted
guanidine’ ” because “between fifty and one hundred substances” fit that
description and the specification did not disclose “any general quality
common to disubstituted guanidines which makes them all effective”).
  2 See also, e.g., Ives v. Hamilton, 

 (1876) (uphold-

ing claim “for an improvement in sawmills” based on “curved guides at
the upper end of the saw,” even though the specification 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,
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                          Opinion of the Court

   Decisions such as Wood and Minerals Separation estab-
lish that a specification 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 Sepa-
ration, 242 U. S., at 270–271; see also Mowry v. Whitney, 

 (1872) (“[T]he definiteness of a specification
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 statu-
tory requirement that a patent’s specification 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 pre-
scribed than they may add to them. See Bilski v. Kappos,

, 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 specification enables the
26 exemplary antibodies it identifies by their amino acid se-
quences. Even Sanofi 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 reasona-
ble degree of experimentation.
——————
would have no difficulty in adopting the improvement, and making suit-
able curves”); Tilghman v. Proctor, 

, 732–733 (1881) (up-
holding claim for process of separating fats and oils even though the spec-
ification “suggests a trial . . . with different degrees of heat so as to
ascertain that which is best for each particular kind of fat”).
16                 AMGEN INC. v. SANOFI

                     Opinion of the Court

   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 defined 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
reflects that this class of antibodies does not include just
the 26 that Amgen has described by their amino acid se-
quences, but a “vast” number of additional antibodies that
it has not. 

; see 

,
*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 fibrous and textile materials for incandescence, and Per-
kins sought to claim all starch glues that work as well as
animal glue for wood veneering, Amgen seeks to claim “sov-
ereignty over [an] entire kingdom” of antibodies. Incandes-
cent Lamp, 

.
   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 de-
vised in the 19th century, glues invented in the 20th, or an-
tibody 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 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 first merely de-
scribes step-by-step Amgen’s own trial-and-error method
for finding functional antibodies—calling on scientists to
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                     Opinion of the Court

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; 

; 

, *10–*13.
The second isn’t much different. It requires scientists to
make substitutions to the amino acid sequences of antibod-
ies 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; 

; 

, *10–*13. Whether methods like a “roadmap”
or “conservative substitution” might suffice to enable other
claims in other patents—perhaps because, as this Court
suggested in Incandescent Lamp, the inventor identifies a
quality common to every functional embodiment, supra, at
13—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. 

.
That is not enablement. More nearly, it is “a hunting li-
cense.” Brenner v. Manson, 

 (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 finds and discloses 26 different
successful lock combinations.” 

 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 21. Sure enough, that kind of “roadmap”
would produce functional combinations. Ibid. But it would
not enable others to make and use functional combinations;
it would instead leave them to “random trial-and-error dis-
covery.” Ibid. Like many analogies, this one may oversim-
plify 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
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                      Opinion of the Court

of attack. First, it suggests that the Federal Circuit erred
by applying an enablement test unmoored from the statu-
tory text. As Amgen sees it, that court conflated the ques-
tion 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 re-
quired to exhaust a genus is dispositive.” 

(emphasis deleted). Instead, the court stressed, the prob-
lem it saw is the same problem we see: Amgen offers per-
sons skilled in the art little more than advice to engage in
“trial and error.” 

 (internal quotation marks omitted).
In any event, we review judgments of the lower courts, not
statements in their opinions. See Black v. Cutter Laborato-
ries, 

 (1956).
   Taking a similar tack, Amgen next argues that the Fed-
eral Circuit erroneously “raise[d] the bar” for enablement of
claims that, like Amgen’s, encompass an entire “genus” of
embodiments defined 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 inven-
tion[s].” 

 (internal quotation marks omitted). Here,
too, we agree with Amgen in principle: There is one statu-
tory enablement standard. But, once more, we do not un-
derstand 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 en-
able. As we have seen, that much is entirely consistent with
Congress’s directive and this Court’s precedents.
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                      Opinion of the Court

   Finally, Amgen warns that an affirmance risks “de-
stroy[ing] incentives for breakthrough inventions.” 

. But striking the proper balance between incentivizing
inventors and ensuring the public receives the full benefit
of their innovations is a policy judgment that belongs to
Congress. Since 1790, Congress has included an enable-
ment 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 reflects Congress’s judg-
ment that if an inventor claims a lot, but enables only a lit-
tle, the public does not receive its benefit of the bargain.
For more than 150 years, this Court has enforced the stat-
utory 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
                                                   Affirmed.