Amicus Curiae Brief — MSN Pharmaceuticals, Inc., et al., Petitioners v. Novartis Pharmaceuticals Corporation

No. 25-225

IN THE

Supreme Court of the United States

_________

MSN PHARMACEUTICALS, INC., ET AL.,

Petitioners,

v.

NOVARTIS PHARMACEUTICALS CORPORATION,

Respondent.

_________

On Petition for a Writ of Certiorari

to the United States Court of Appeals

for the Federal Circuit

_________

BRIEF FOR SIGMAPHARM

LABORATORIES, LLC, AS AMICUS CURIAE

IN SUPPORT OF PETITIONERS

_________

GIANNI P. SERVODIDIO

JENNER & BLOCK LLP

1155 Avenue of the Americas

New York, NY 10036

MARY E. KOHART

SIGMAPHARM

LABORATORIES, LLC

3375 Progress Drive

Bensalem, PA 19020

ADAM G. UNIKOWSKY

Counsel of Record

JONATHAN J. MARSHALL

JENNER & BLOCK LLP

1099 New York Avenue,

NW, Suite 900

Washington, DC 20001

(202) 639-6000

aunikowsky@jenner.com

i

TABLE OF CONTENTS

TABLE OF AUTHORITIES .......................................... ii

INTEREST OF AMICUS CURIAE ............................. 1

INTRODUCTION AND SUMMARY OF THE

ARGUMENT ................................................................... 3

ARGUMENT ...................................................................... 8

I.

II.

The Federal Circuit’s Precedents on the

Enablement and Written-Description

Requirements for After-Arising

Technology Are In Disarray .................................... 8

A.

The Case Law on Section 112(a) and

After-Arising Technology Is

Incoherent ......................................................... 8

B.

The Decision Below Casts This

Important Area of Patent Law into

Further Chaos................................................. 11

The Uncertainty As to the Scope of

Pharmaceutical Patents Makes It Difficult

for Generic-Pharmaceutical Manufacturers

to Do Business.......................................................... 15

CONCLUSION ................................................................ 20

ii

TABLE OF AUTHORITIES

CASES

Amgen Inc. v. Sanofi, 598 U.S. 594

(2023) ................................................................ 2-4, 14-15

Ariad Pharmaceuticals, Inc. v. Eli Lilly & Co.,

598 F.3d 1336 (Fed. Cir. 2010) (en banc) .................... 5

Caraco Pharmaceutical Laboratories, Ltd. v.

Novo Nordisk A/S, 566 U.S. 399 (2012) .................... 16

Chiron Corp. v. Genentech, Inc., 363 F.3d 1247

(Fed. Cir. 2004) .........................................................9-12

Hogan, In re, 559 F.2d 595 (C.C.P.A. 1977) ................ 10

Hyatt, In re, 708 F.2d 712 (Fed. Cir. 1983) ................. 10

Phillips v. AWH Corp., 415 F.3d 1303

(Fed. Cir. 2005) (en banc) ........................................... 13

Plant Genetic Systems, N.V. v. DeKalb Genetics

Corp., 315 F.3d 1335 (Fed. Cir. 2003) ......................8-9

SRI International v. Matsushita Electric Corp.

of America, 775 F.2d 1107 (Fed. Cir. 1985)

(en banc) ........................................................................ 14

Thorner v. Sony Computer Entertainment

America LLC, 669 F.3d 1362 (Fed. Cir. 2012)......... 13

Wright, In re, 999 F.2d 1557 (Fed. Cir. 1993) ............. 10

STATUTES

35 U.S.C. § 112(a)......................................... 2-8, 13, 17-18

iii

RULES

Sup. Ct. R. 37.2.................................................................. 1

Sup. Ct. R. 37.6 ................................................................. 1

OTHER AUTHORITIES

Association for Accessible Medicines, The U.S.

Generic & Biosimilar Medicines Savings

Report (Sept. 2025), https://accessiblemeds.org

/wp-content/uploads/2025/09/AAM-2025Generic-Biosimilar-Medicines-Savings-ReportWEB.pdf ....................................................................... 15

Briesacher, Becky A., et al., Medication

Adherence and the Use of Generic Drug

Therapies, 15 Am. J. Managed Care 450 (2009) ...... 16

Choudhry, Niteesh K., et al., Improving

Adherence to Therapy and Clinical Outcomes

While Containing Costs: Opportunities from

the Greater Use of Generic Medications; Best

Practice Advice from the Clinical Guidelines

Committee of the American College of

Physicians, Annals Internal Med. (Nov. 24,

2015), https://doi.org/10.7326/M14-2427.................... 16

Cubanski, Juliette, et al., What Does the Federal

Government Spend on Health Care?, KFF

(Feb. 24, 2025), https://www.kff.org/medicaid

/what-does-the-federal-government-spend-onhealth-care .................................................................... 19

iv

Masur, Jonathan S. & Lisa Larrimore

Ouellette, Disclosure Puzzles in Patent Law,

92 U. Chi. L. Rev. (forthcoming 2025),

https://chicagounbound.uchicago.edu

/cgi/viewcontent.cgi?article=2376&context=

public_law_and_legal_theory .................................... 12

Medicare and Medicaid Expenditures:

Prescription Drugs; 2024 Report,

Rios Partners Health of Health Rpt.,

https://www.healthofhealth.org/medicare-andmedicare-expenditures-prescription-drugs

(last visited Sept. 28, 2025)......................................... 19

NHE Fact Sheet, Ctrs. for Medicare & Medicaid

Servs., https://www.cms.gov/dataresearch/statistics-trends-andreports/national-health-expenditure-data

/nhe-fact-sheet (last updated June 24, 2025) ........... 19

1

INTEREST OF AMICUS CURIAE 1

Amicus curiae Sigmapharm Laboratories, LLC, is a

manufacturer of generic pharmaceutical products. Sigmapharm was founded in 2005 as a small, specialty formulation house conducting only pilot-scale development

of unique, difficult-to-formulate products using proprietary drug-delivery systems. For over a decade, however, Sigmapharm has developed, manufactured, and

marketed unique, cost-effective, high-barrier-to-entry

generic drug products under its own label. The manufacture and marketing of generic pharmaceuticals are a

substantial portion of Sigmapharm’s business, and Sigmapharm has a particular interest in the development of

the law concerning pharmaceutical patents.

Generic manufacturers can operate only if they have

an accurate understanding of the scope of brand manufacturers’ patent rights. Like other generic manufacturers, the viability of Sigmapharm’s business depends on

steering clear of brand manufacturers’ patents and predicting the likely outcome of patent-infringement suits

brought by brand manufacturers. Without a clear and

predictable understanding of the scope of brand manufacturers’ patents, generic manufacturers like Sigmapharm cannot make informed business decisions about

product development or the timing of market entry.

1 Pursuant to this Court’s Rule 37.6, amicus states that this brief

was not authored in whole or in part by counsel for any party, and

that no person or entity other than amicus and its counsel made a

monetary contribution intended to fund the preparation or submission of this brief. Counsel of record for the parties received timely

notice of the intent to file this brief pursuant to this Court’s Rule

37.2.

2

Generic manufacturers must make enormous upfront investments for generic formulations of branded drugs—

developing manufacturing processes and facilities, obtaining regulatory approval, and performing bioequivalence studies—long before the generic drugs generate

any revenue. Key to this long-term strategic planning is

an assessment of the validity and scope of brand manufacturers’ patents.

This case demonstrates the dire unpredictability surrounding a recurring and important question of patent

law: the role of after-arising technology in a court’s analysis of whether a patent’s specification properly describes and enables the full scope of the patent, as

required by 35 U.S.C. § 112(a). In Sigmapharm’s view,

the decision below reflects—and exacerbates—the lack

of clarity as to the validity and scope of a patent that fails

to enable or describe embodiments utilizing technology

nonexistent at the time of the patent application. Unpredictability as to the scope and validity of brand manufacturers’ patents makes it difficult for generic

manufacturers to do business. And outcomes like the

ones in this case provide a undue windfall to brand manufacturers—rewarding broadly construed claims without imposing the Patent Act’s requirements that the full

scope of a claim be enabled and described.

Sigmapharm thus has a compelling interest in ensuring that the question presented here, which applies

across patent law but has outsize importance in the pharmaceutical industry, is resolved. This Court recently

granted certiorari to clear up uncertainty as to the enablement requirement with respect to patents that claim

entire genuses. See Amgen Inc. v. Sanofi, 598 U.S. 594,

3

603-04 (2023). The question presented here is related,

but distinct, to the one addressed in Amgen. This Court

should likewise grant certiorari to continue to bring

much-needed clarity to the Patent Act’s written-description and enablement requirements.

INTRODUCTION AND

SUMMARY OF THE ARGUMENT

In Amgen Inc. v. Sanofi, 598 U.S. 594 (2023), this

Court held that to satisfy 35 U.S.C. § 112(a)’s enablement requirement, a patent’s specification “must enable

the full scope of the invention as defined by its claims.”

Amgen, 598 U.S. at 610. In that case, Amgen had sought

to patent the entire genus of antibodies that bind to a

particular protein and accomplish a particular function.

Id. at 602. The patent’s specification identified 26 such

antibodies but claimed all antibodies with similar behavior—potentially millions more. Id. at 602-03, 613. The

patentee did not purport to have discovered each such

antibody, but it argued that it had properly enabled their

discovery nonetheless. Id. at 613-14. The question presented thus related to the scope of the enablement requirement when a patentee claims more than it has

actually discovered.

Amgen added clarity to the Patent Act’s enablement

requirement in the case of patents that claim entire genuses but identify and enable only specific species.

Amgen, however, did not address or resolve a related

question: what happens when a patent, as construed, covers embodiments utilizing technology that was not specifically described because it did not exist at the time of

the patent application? This Court’s holding in Amgen

was that a specification does not enable claimed subject

4

matter if it would take a person having ordinary skill in

the art (or PHOSITA) more than a “reasonable amount

of experimentation to make and use” what is claimed.

598 U.S. at 612. But of course, if an embodiment involves

technology that did not exist at the time of the patent

application, then it follows that a PHOSITA would need

to undertake undue experimentation to implement that

embodiment—after all, he would have to invent something novel in order to make and use it. At the same

time, perhaps the patentee ought not be faulted for

claiming too much, as it may not have even known that

future advances would mean there were unenabled and

undescribed embodiments. Amgen did not speak to

whether or how the enablement and the related writtendescription requirements apply in this scenario.

To understand when and why the question presented

here—how Section 112(a)’s twin requirements apply in

the context of after-arising technology—arises, consider

the following hypothetical. Suppose a patent claims a

method of using a “transistor” to perform some novel

computing task. The patent’s specification properly discloses how to use a transistor to perform the task in a

way that a PHOSITA would be able to apply to all transistors available as of the time of the patent application. 2

Suppose further, however, that years after the patent is

2 The Amgen question presented would arise if not all types of tran-

sistor would work for the task, but the patentee claimed all those

that do without specifying exactly which are viable options and

which are not. So long as a PHOSITA could distinguish between

viable and inviable species of transistor with a “reasonable amount

of experimentation,” such a specification would satisfy the enablement requirement. Amgen, 598 U.S. at 612.

5

issued, someone invents a new and improved variety of

transistor. And suppose the new transistor performs

the patented task more efficiently. 3

Does it infringe the patent to use the new type of

transistor to perform the task? As a matter of claim construction, the answer is likely yes. The new variety of

transistor is likely a “transistor” as claimed by the patent and thus using it to perform the task literally infringes the patent’s claims—just as in this case, a

complex of valsartan and sacubitril was deemed a “combination” as construed in the patent and thus indisputably literally infringes. Pet. App. 7a-9a; see id. at 88a-91a.

The critical question, instead, is whether the patent can

be said to satisfy Section 112(a)’s written-description

and enablement requirements. If the after-arising technology should be disregarded for purposes of this inquiry (as the Federal Circuit sometimes holds, and as it

held below), the patent is perfectly valid. But if the after-arising technology is considered, it is difficult to see

how the patent’s specification could either properly describe or enable using the newly invented transistor.

The written-description requirement is meant to “convey[] to those skilled in the art that the inventor had possession of the claimed subject matter as of the filing

date,” Ariad Pharms., Inc. v. Eli Lilly & Co., 598 F.3d

1336, 1351 (Fed. Cir. 2010) (en banc), but obviously the

patentee did not have the capacity to perform the

claimed task using the as-yet-nonexistent transistor

3 One can also suppose that the new transistor does a worse job at

the task—or maybe performs the same. The variety of possibilities

underscores the need for a comprehensive framework to govern this

scenario.

6

when it applied for the patent. Nor could the patentee

have possibly enabled the task using the new transistor,

which had not yet been invented. Does that make the

patent invalid under Section 112(a)? Does it require narrowing the scope of the patent? Some other result?

Certiorari is warranted to resolve that question here.

The Federal Circuit’s precedents addressing Section

112(a)’s requirements in the case of after-arising technology are inconsistent and confusing. And the decisions

in this case only add to the confusion—the district court

applied a precedent under which after-arising technology is seemingly irrelevant for purposes of Section

112(a)’s enablement requirement but seemingly fatal to

the patent for purposes of Section 112(a)’s related written-description requirement. That is a confusing result

in its own right. The Federal Circuit reversed that determination without acknowledging that it was departing from its clear precedent applied by the district court,

only exacerbating the chaos.

The upshot is not just a judgment of infringement in

this suit: it is a pall of confusion hovering over patent law

in a way that causes particular concern to manufacturers

of generic pharmaceuticals. Generic manufacturers’ entire business is based on developing and marketing products that avoid infringing brand manufacturers’ patents.

That business cannot operate without the ability to predict with high confidence what those patents actually

cover. The more unpredictable the result in a patentinfringement lawsuit, the more reluctant generic manufacturers will be to bring new generic drugs to market

at all. And the main losers are ultimately American patients, who rely heavily on high-quality and affordable

7

generic medicines. The American taxpayer loses as well,

as the availability of generic medications saves the Medicare and Medicaid programs countless billions each

year.

The facts giving rise to this case are not unusual. Respondent Novartis Pharmaceuticals Corporation owns a

patent (the ’659 patent) on the use of a “combination” of

two drugs (valsartan and sacubitril) when used in a 1:1

ratio to treat heart failure. Pet. App. 4a-7a. After the

patent issued, however, a new method of combining

these two drugs was developed—it was discovered that

they could be combined as a “complex.” Id. at 15a. Petitioners developed a generic drug combining valsartan

and sacubitril in complex form. Id. at 9a, 23a-24a. The

patent was construed to cover petitioners’ method of

combining the drugs, even though that method did not

exist at the time of the patent application. The question

is whether the patent is invalid for failure to enable or

describe combining the two drugs as a complex.

These facts can recur because developments in physical chemistry often lead to new methods of synthesizing

patented medications. Sometimes the patent may be

construed not to cover the novel synthetic method, in

which case the patent will not be invalidated under Section 112(a) but the infringement lawsuit will fail. But if

the patentee obtains a broad claim construction that ensnares an accused product utilizing the after-arising

technology, is the patent’s specification immune from

the ordinary enablement and written-description requirements?

This case presents a clean opportunity for this Court

to clear up the doctrine and provide desperately needed

8

guidance on how to apply Section 112(a)’s requirements

in the case of after-arising technology. The petition

should be granted.

ARGUMENT

I.

THE FEDERAL CIRCUIT’S PRECEDENTS

ON THE ENABLEMENT AND WRITTENDESCRIPTION REQUIREMENTS FOR AFTER-ARISING TECHNOLOGY ARE IN DISARRAY.

The Federal Circuit’s precedents on the question

presented are self-contradictory and unclear. The decision below only makes things worse. Without this

Court’s intervention, clarity is unlikely to come.

A.

The Case Law on Section 112(a) and AfterArising Technology Is Incoherent.

As the petition chronicles (at 15-26), different

strands of the Federal Circuit’s case law take different

approaches to the question presented here.

For instance, in Plant Genetic Systems, N.V. v. DeKalb Genetics Corp., 315 F.3d 1335 (Fed. Cir. 2003), the

Federal Circuit seemed to hold that after-arising technology poses an enablement problem if a patent’s claims

are construed to cover embodiments utilizing that new

technology. Certain claims of the patent at issue were

construed to cover all plant cells, both monocotyledons

(or “monocots,” meaning a type of flowering plant in

which “the initial development of the seed produces one

leaf”) and dicotyledons (or “dicots,” with two leaves in

the initial development). Id. at 1338. All the examples

disclosed in the patent’s specification were dicots, but

9

the allegedly infringing product was a monocot. Id. As

of the relevant priority date, the relevant technology as

concerned monocots did not yet exist. Id.

The Federal Circuit held that the patent failed the

enablement requirement because it claimed uses relating to monocots without enabling those uses. Plant Genetic Sys., 315 F.3d at 1339-41. The court noted that had

the patentee argued that the claims “were not understood by those skilled in the art as encompassing monocots when the [patent] was filed,” it could have avoided

invalidation of the claims. Id. at 1341. But the patentee

had insisted that its claims covered monocots, because

that was the only way to sue the defendant for infringement. Id. The court held that, having made that choice

as to a broad claim construction, the scope of the Patent

Act’s enablement requirement expanded correspondingly, and the patentee had an obligation to enable those

uses relating to monocots as well. See id. That is, the

court rejected the notion that the patentee was at once

“entitled to both a broad scope of coverage and a lower

standard of enablement.” Id. The specification having

failed to enable this as-yet-nonexistent technology, the

patent was invalid.

The next year, the Federal Circuit decided Chiron

Corp. v. Genentech, Inc., 363 F.3d 1247 (Fed. Cir. 2004).

The patent at issue in Chiron claimed certain monoclonal

antibodies and disclosed a method of making the antibodies using mouse cells. Id. at 1250-51. The antibodies

could also be created using chimeric antibody technology, but that technology was not first disclosed until several months after the relevant application date. Id. at

1251. The claims at issue were “broadly construed” to

10

encompass both the disclosed murine antibodies and the

undisclosed, unenabled, after-arising chimeric antibodies. Id. at 1252. The defendant’s chimeric antibodies

were therefore deemed infringing. Id.

The Federal Circuit held that the failure to enable

chimeric antibodies did not render the patent invalid.

Chiron, 363 F.3d at 1253-55. The court recited that ordinarily a patent specification must enable the full scope

of the claims as construed. See id. at 1253. But relying

on In re Hogan, 559 F.2d 595 (C.C.P.A. 1977), the court

stated that this requirement could be overlooked in the

case of “technology that arises after the date of application” because “[s]uch disclosure would be impossible.”

Chiron, 363 F.3d at 1254 (citing Hogan, 559 F.2d at 60506). The chimeric antibodies, though within the patent’s

scope as its claims were construed, were deemed “outside the bounds of the enablement requirement.” Id.

The Chiron court distinguished Plant Genetic Systems on the basis that the unenabled monocots there had

been “nascent technology when the application was

filed,” unlike the chimeric antibodies in Chiron (or the

amorphous propylene at issue in Hogan). Chiron, 363

F.3d at 1257. The Federal Circuit thus appeared to

adopt a rule that if some aspects of the technology had

begun to emerge as of the date of the patent application,

then the usual rule applied: the specification “must enable one of ordinary skill in the art to practice ‘the full

scope of the claimed invention,’” and “‘[t]he enabling disclosure of the specification [must] be commensurate in

scope with the claim under consideration.” Id. at 1253

(alterations in original) (first quoting In re Wright, 999

F.2d 1557, 1561 (Fed. Cir. 1993); and then quoting In re

11

Hyatt, 708 F.2d 712, 714 (Fed. Cir. 1983)). But if that

technology did not exist at all, then (for some unspecified reason) the enablement requirement apparently did

not apply with its usual force, and the patentee was entitled to a broad monopoly even as to embodiments that

it had failed to enable. See id. at 1254 (“The law does not

expect an applicant to disclose knowledge invented or

developed after the filing date. . . . The law requires an

enabling disclosure for nascent technology because a

person of ordinary skill in the art has little or no

knowledge independent from the patentee’s instruction.”).

Despite this relaxation of the enablement requirement, the Chiron court proceeded to invalidate the patent on written-description grounds. 363 F.3d at 125556. In fact, the analysis was quite straightforward: the

court explained that “the Chiron scientists, by definition,

could not have possession of, and disclose, the subject

matter of chimeric antibodies that did not even exist at

the time of the . . . application.” Id. at 1255. The court

did not grapple with why this holding made sense in light

of its enablement holding—or what good the principle

that after-arising technology need not be enabled would

be if that technology must still be disclosed to satisfy the

Patent Act’s written-description requirement.

B.

The Decision Below Casts This Important

Area of Patent Law into Further Chaos.

Indeed, the proceedings in this case are indicative of

the hopelessness of predicting how the question presented might be resolved in any particular case. The district court here followed an approach it believed was

dictated by the Federal Circuit’s decision in Chiron. See

12

Pet. App. 67a-75a (declining to invalidate the ’659 patent

on enablement grounds under Chiron); id. at 77a-80a (invalidating the patent on written-description grounds under Chiron). Correct or not, that at least appears to be

the path dictated by one on-point Federal Circuit precedent.

In reversing the district court with respect to written description, the court of appeals did not comment on

the trial court’s application of Chiron, or even mention

Chiron at all in its analysis. See Pet. App. 13a-17a. Instead, the court concluded that Novartis’s invention “is

plainly described throughout the specification.” Id. at

14a; see id. at 14a-15a. The Chiron court had considered

it “axiomatic[]” that a patentee “cannot satisfy the written description requirement for . . . new matter” claimed

by the patent but embodied by after-arising technology.

363 F.3d at 1255. Yet in the decision below, that axiomatic principle fell by the wayside. It is anyone’s guess

what the law of written description actually is moving

forward, or which version of that law will be applied in

any particular case. 4

Not only did the Federal Circuit depart from its precedent with no explanation, the analysis it did offer is difficult to understand. With respect to the writtendescription requirement, the court of appeals held that

“complexes need not have been described” in the ’659

4 See Jonathan S. Masur & Lisa Larrimore Ouellette, Disclosure

Puzzles in Patent Law, 92 U. Chi. L. Rev. (forthcoming 2025)

(manuscript at 42-43), https://chicagounbound.uchicago.edu

/cgi/viewcontent.cgi?article=2376&context=public_law_and_legal_

theory (noting the inconsistency between Chiron and the decision

below).

13

patent because the patent “does not claim . . . complexes.” Pet. App. 13a. In the court’s view, though the

’659 patent covers complexes, it does not claim them. Id.

at 15a-16a. The court stated that to mesh these two inquiries is to “conflate[] the distinct issues of patentability and infringement.” Id. at 16a. This suggestion is not

consistent with well-established patent principles.

It is a fundamental tenet of patent law that a patent’s

claims—as its words are construed—“define the metes

and bounds of the patentee’s invention.” Thorner v.

Sony Comput. Ent. Am. LLC, 669 F.3d 1362, 1367 (Fed.

Cir. 2012). Patent law does not recognize any distinction

between what a patent’s words are construed to cover

and what the patent “claims.” Here, the ’659 patent was

construed to cover complexes. That means the patent

claims complexes. And it is equally fundamental that

the written description required by Section 112(a) must

“describe the invention set forth in the claims.” Phillips

v. AWH Corp., 415 F.3d 1303, 1312 (Fed. Cir. 2005) (en

banc). There is no room for some sort of liminal category

of subject matter that is at once sufficiently described by

the patent claims’ words so as to be within the scope of

the patentee’s monopoly, yet evade the Patent Act’s

written-description requirement. After all, if a patent’s

claims sets out its metes and bounds and precisely establishes the scope of the patentee’s monopoly, what can it

possibly mean to say that a patent covers something it

does not claim?

To defend this novel and jarring distinction between

a patent’s claims and its coverage, the Federal Circuit

noted that “‘[c]laims are not construed “to cover” or “not

to cover” the accused [product],’” and instead “‘[i]t is

14

only after the claims have been construed without reference to the accused device that the claims, as so construed, are applied to the accused device to determine

infringement.’” Pet. App. 16a (second alteration in original) (quoting SRI Int’l v. Matsushita Elec. Corp. of Am.,

775 F.2d 1107, 1118 (Fed. Cir. 1985) (en banc)). But that

principle, true as it may be, is irrelevant to the question

at hand. The ’659 patent was not construed here with

reference to petitioners’ generic drug; it was construed

to cover complexes (manufactured by anyone) through

its use of the word “combination.” See id. at 88a-91a. It

therefore claims complexes. Wordplay aside, this conclusion is unavoidable, and district courts are certain to

struggle to apply the Federal Circuit’s analysis going

forward.

The court of appeals offered a slightly different, but

still inscrutable, analysis with respect to enablement.

The court held that the ’659 patent could not be invalid

for failure to enable valsartan-sacubitril complexes because the patent “does not expressly claim complexes.”

Pet. App. 19a; see id. at 17a-19a. Here, the court seemed

to see as critical that the ’659 patent does not explicitly

mention complexes; if it had, it would likely be unavoidable that the enablement requirement is not met. But

why should the failure to expressly claim complexes affect the enablement requirement given the premise that

the patent does, in fact, claim complexes? Generally,

“the specification must enable the full scope of the invention as defined by its claims.” Amgen, 598 U.S. at 610.

In Amgen, the claims were construed to cover the entirety of a species, so this Court held that because undue

experimentation was necessary to find the elements of

15

that species, “Amgen ha[d] failed to enable all that it

ha[d] claimed.” Id. at 613. It is hard to see why an equivalent analysis should not hold here—if the ’659 patent is

construed to claim complexes, but it does not enable

complexes, then how has Novartis “enable[d] all that it

has claimed”? Id.

II.

THE UNCERTAINTY AS TO THE SCOPE OF

PHARMACEUTICAL PATENTS MAKES IT

DIFFICULT FOR GENERIC-PHARMACEUTICAL MANUFACTURERS TO DO BUSINESS.

The state of the Federal Circuit’s case law on the

question presented is untenable. Generic pharmaceuticals play a critical role in providing American patients

with access to life-saving medications. But the uncertainty in the patent law governing pharmaceuticals

makes it difficult for the companies that manufacture

those generic drugs to operate.

Generic medicines play an enormously important

role in the U.S. healthcare system. Generic manufacturers like Sigmapharm develop and bring to market highquality generic drugs that comprise the vast majority of

prescriptions while costing just a fraction of the price.

In 2024, for instance, generics accounted for approximately 90% of all prescriptions filled in the United

States while accounting for just 12% of all prescriptiondrug spending. 5

The availability of generic and

5 Ass’n for Accessible Meds., The U.S. Generic & Biosimilar Med-

icines Savings Report 2 (Sept. 2025), https://accessiblemeds.org/wpcontent/uploads/2025/09/AAM-2025-Generic-Biosimilar-MedicinesSavings-Report-WEB.pdf.

16

biosimilar medicines saved patients and taxpayers $467

billion in 2024 alone, and a total of $3.4 trillion over the

last ten years. 6 In an era where inflation is a major concern to U.S. consumers, generic medications are continually subject to “severe deflation.” 7 And the availability

of generic medications is strongly associated with positive, cost-effective health outcomes for patients. 8 To put

it simply, when generic drugs do not make it to market,

patients suffer because they simply cannot afford highpriced, branded versions of the life-saving medicines

they need.

The viability of the pharmaceutical-drug industry

turns on a delicate dance around brand manufacturers’

patent rights. Generic manufacturers need to understand the precise scope of pharmaceutical patents so

that they can design around them or utilize the HatchWaxman “skinny label” process to carve out patented

uses of compounds that are themselves no longer patented. See Caraco Pharm. Lab’ys, Ltd. v. Novo Nordisk

A/S, 566 U.S. 399, 405-07 (2012). Designing around a patent will often involve changes in the manufacturing processes or the delivery mechanisms for the drug—

6 Id. at 10.

7 Id. at 13.

8 See generally Becky A. Briesacher et al., Medication Adherence

and the Use of Generic Drug Therapies, 15 Am. J. Managed Care

450 (2009); Niteesh K. Choudhry et al., Improving Adherence to

Therapy and Clinical Outcomes While Containing Costs: Opportunities from the Greater Use of Generic Medications; Best Practice

Advice from the Clinical Guidelines Committee of the American

College of Physicians, Annals Internal Med. (Nov. 24, 2015),

https://doi.org/10.7326/M14-2427.

17

perhaps, as here, utilizing some after-arising technology.

Analyzing brand manufacturers’ patents and developing

these non-infringing manufacturing processes involves

enormous investments, and generic manufacturers will

not make these investments if they cannot have reasonable certainty of success in an infringement lawsuit. The

decision below (like the Federal Circuit’s other decisions

sporadically relaxing Section 112(a)’s enablement and

written-description requirements) throws a wrench in

this system.

For starters, the court of appeals’ approach in this

case allows brand manufacturers to unduly expand the

scope of their monopolies, claiming formulations and

processes that were not disclosed or enabled in their patent specifications. This makes it extraordinarily difficult for generic manufacturers to design around patents

and locks generics out of the market for decades. The

Federal Circuit’s uneven approach to the question presented thus fundamentally alters the competitive landscape of the pharmaceutical industry, systematically

disadvantaging generic manufacturers and providing a

windfall for brand manufacturers. The decision below

provides a dangerous roadmap for brand manufacturers

bringing infringement suits, as it seemingly allows—

against all patent-law principles previously known—for

certain subject matter to be claimed by a patent without

being described or enabled by the patent’s specification.

Indeed, even when generic manufacturers themselves

develop new technology to improve the manufacture or

delivery of a drug, the brand manufacturer can argue

that this new process is within the scope of its valid

claims even though it could not possibly have described

18

or enabled the new technique. Generic manufacturers

are left in an impossible position.

While these pernicious effects could stifle innovation

in any industry, the need for predictability in the context

of generic pharmaceuticals makes the state of the Federal Circuit’s precedent particularly problematic. Generic manufacturers cannot make sound investment

decisions without predictability as to the scope and validity of brand manufacturers’ patents. Developing a generic drug requires years of investment before any

revenue is generated—investment carefully tailored to

complex assessments of whether brand manufacturers’

patents can be invalidated or avoided. The unpredictability of how after-arising technology will be treated in a

court’s Section 112(a) analysis makes these assessments

inherently unreliable.

The cumulative effect of these problems is to significantly increase the barriers to generic medications entering the market, reduce competition, and increase

prices. Generic manufacturers faced with the unpredictable legal landscape must either accept unmanageably

high litigation risks or avoid markets entirely even

where there is room for beneficial competition. And

smaller generic manufacturers with limited resources

may be particularly disadvantaged—these companies

have less capacity to accept litigation risk and are thus

more likely to avoid developing drugs where the existing

patents have unpredictable scope.

In the end, it is not only patients who lose when a generic manufacturer cannot bring a new generic drug to

market—it is the American taxpayer who loses as well.

Programs related to health care represent the largest

19

category of federal spending—nearly $2 trillion in fiscal

year 2024, and over a quarter of all federal expenditures

for that year. 9 A significant portion of that money goes

toward prescription drugs in the Medicare and Medicaid

programs. 10 Higher barriers to market entry for generic

manufacturers means higher drug prices—leading inevitably to higher taxes, lower quality of care, or both.

9 See Juliette Cubanski et al., What Does the Federal Government

Spend on Health Care?, KFF (Feb. 24, 2025), https://www.kff.org

/medicaid/what-does-the-federal-government-spend-on-healthcare.

10 In 2023, the federal government spent nearly $200 billion on pre-

scription drugs, and that number has grown significantly each recent year. See Medicare and Medicaid Expenditures: Prescription

Drugs; 2024 Report, Rios Partners Health of Health

Rpt.,

https://www.healthofhealth.org/medicare-and-medicareexpenditures-prescription-drugs (last visited Sept. 28, 2025);

see also NHE Fact Sheet, Ctrs. for Medicare & Medicaid

Servs., https://www.cms.gov/data-research/statistics-trends-andreports/national-health-expenditure-data/nhe-fact-sheet (last updated June 24, 2025).

20

CONCLUSION

For the foregoing reasons and those stated in the petition for a writ of certiorari, the petition should be

granted.

Respectfully submitted.

GIANNI P. SERVODIDIO

JENNER & BLOCK LLP

1155 Avenue of the Americas

New York, NY 10036

MARY E. KOHART

SIGMAPHARM

LABORATORIES, LLC

3375 Progress Drive

Bensalem, PA 19020

OCTOBER 2025

ADAM G. UNIKOWSKY

Counsel of Record

JONATHAN J. MARSHALL

JENNER & BLOCK LLP

1099 New York Avenue,

NW, Suite 900

Washington, DC 20001

(202) 639-6000

aunikowsky@jenner.com