United States Court of Appeals 

for the Federal Circuit ______________________

NUVO PHARMACEUTICALS (IRELAND) 

DESIGNATED ACTIVITY COMPANY, HORIZON

MEDICINES LLC,

Plaintiffs-Cross-Appellants

v.

DR. REDDY’S LABORATORIES INC., DR. REDDY’S 

LABORATORIES, LTD., MYLAN, INC., MYLAN 

PHARMACEUTICALS INC., MYLAN 

LABORATORIES LIMITED,

Defendants-Appellants

LUPIN LTD., LUPIN PHARMACEUTICALS, INC.,

Defendants-Appellees

______________________

2017-2473, 2017-2481, 2017-2484, 2017-2486, 2017-2489, 

2017-2491, 2017-2492, 2017-2493

______________________

Appeals from the United States District Court for the 

District of New Jersey in Nos. 3:11-cv-02317-MLC-DEA, 

3:13-cv-00091-MLC-DEA, 3:13-cv-04022-MLC-DEA, Judge 

Mary L. Cooper.

______________________

Decided: May 15, 2019

______________________

JAMES B. MONROE, Finnegan, Henderson, Farabow, 

Garrett & Dunner, LLP, Washington, DC, argued for 

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2 NUVO PHARMACEUTICALS v. DR. REDDY’S LABORATORIES

plaintiffs-cross-appellants. Plaintiff-cross-appellant Horizon Medicines LLC also represented by CHARLES COLLINSCHASE. 

 STEPHEN M. HASH, Baker Botts, LLP, Austin, TX, for 

plaintiff-cross-appellant Nuvo Pharmaceuticals (Ireland) 

Designated Activity Company. Also represented by 

JEFFREY SEAN GRITTON. 

 ALAN HENRY POLLACK, Windels Marx Lane & Mittendorf LLP, Madison, NJ, argued for all defendants-appellants. Defendants-appellants Dr. Reddy's Laboratories 

Inc., Dr. Reddy's Laboratories, Ltd. also represented by 

STUART D. SENDER. 

 ANDREW DUFRESNE, Perkins Coie LLP, Madison, WI, 

argued for all defendants-appellants. Defendants-appellants Mylan, Inc., Mylan Pharmaceuticals Inc., Mylan Laboratories Limited also represented by AUTUMN N. NERO; 

DAN L. BAGATELL, Hanover, NH; SHANNON BLOODWORTH, 

Washington, DC. 

 SAILESH K. PATEL, Schiff Hardin LLP, Chicago, IL, for 

defendants-appellees Lupin Ltd., Lupin Pharmaceuticals, 

Inc. 

 ______________________

Before PROST, Chief Judge, CLEVENGER and WALLACH,

Circuit Judges.

CLEVENGER, Circuit Judge.

Dr. Reddy’s Laboratories, Inc., Mylan Pharmaceuticals, and Lupin Pharmaceuticals (collectively, “the Generics”) appeal from the final judgment of the United States

District Court for the District of New Jersey following a 

bench trial upholding the asserted claims of U.S. Patent 

Nos. 6,926,907 (“the ’907 patent”) and 8,557,285 (“the ’285 

patent”) as nonobvious under 35 U.S.C. § 103, enabled 

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NUVO PHARMACEUTICALS v. DR. REDDY’S LABORATORIES 3

under 35 U.S.C. § 112, and adequately described under 

§ 112. Nuvo Pharmaceuticals, Inc. and Horizon Pharma 

(collectively, “Nuvo”) cross-appeal from the district court’s 

grant of summary judgment of noninfringement to Dr. 

Reddy’s, concluding that one of its drug products will not 

infringe the claims of the ’907 patent. For the reasons set 

forth below, we reverse the appeal and dismiss the crossappeal.

BACKGROUND

I

Non-steroidal anti-inflammatory drugs, also known as 

NSAIDs, control pain. Common NSAIDs include, among 

others, aspirin and naproxen. While NSAIDs control pain, 

they also have the undesirable side effect of causing gastrointestinal problems such as ulcers, erosions, and other 

lesions in the stomach and upper small intestine. Some 

theorize that the undesirable side effect is tied to the combination of NSAID with the presence of acid in the stomach 

and upper small intestine. So, to treat the side effect, some

practitioners began prescribing acid inhibitors to be taken 

by a patient along with the NSAID. The NSAID treats the 

pain while the acid inhibitor reduces the acidity in the gastrointestinal tract, which is achieved by increasing the pH 

level in the tract. Common acid inhibitors include, among 

others, proton pump inhibitors (“PPIs”) like omeprazole 

and esomeprazole.

The combination therapy had complications. First, 

stomach acid degraded the PPI before it could reach the 

small intestine. To fix that issue, an enteric coating that 

wears off after a certain amount of time has elapsed was 

placed around the PPI. Second, if the NSAID was released 

before the acid inhibitor had enough time to raise the pH

level in the tract, patients would continue to suffer gastrointestinal damage. To address those complications, Dr. 

John Plachetka invented a new drug form that coordinated 

the release of an acid inhibitor and an NSAID in a single 

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tablet. The tablet contained a core of an NSAID like 

naproxen in an amount effective to treat pain, an enteric 

coating around the NSAID that prevents its release before 

the pH increases to a certain desired level, and an acid inhibitor like PPI around the outside of the enteric coating 

that actively works to increase the pH to the desired level. 

Dr. Plachetka’s invention contemplates using some 

amount of uncoated PPI to allow for its immediate release 

into a patient’s stomach and upper small intestine. Dr. 

Plachetka recognized problems associated with uncoated 

PPI, namely that without a coating, the PPI is at risk of 

destruction by stomach acid—thereby undermining the 

therapeutic effectiveness of the PPI.

Dr. Plachetka received the ’907 patent on his invention, 

which he assigned to Pozen Inc. He also received the ’285 

patent, which is a division of an abandoned application 

that was a division of another application that itself was a 

continuation-in-part of the application that resulted in the 

’907 patent. The ’285 patent is also assigned to Pozen. The 

two patents bear the same title, “Pharmaceutical Compositions for the Coordinated Delivery of NSAIDs,” and have 

nearly identical specifications.

Claim 1 of the ’907 patent and claim 1 of the ’285 patent 

are representative. They read as follows:

1. A pharmaceutical composition in unit dosage 

form suitable for oral administration to a patient, 

comprising:

(a) an acid inhibitor present in an amount 

effective to raise the gastric pH of said patient to at least 3.5 upon the administration of one or more of said unit dosage 

forms;

(b) a non-steroidal anti-inflammatory drug 

(NSAID) in an amount effective to reduce 

or eliminate pain or inflammation in said 

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patient upon administration of one or more 

of said unit dosage forms;

and wherein said unit dosage form provides for coordinated release such that:

i) said NSAID is surrounded by a coating 

that, upon ingestion of said unit dosage 

form by said patient, prevents the release 

of essentially any NSAID from said dosage 

form unless the pH of the surrounding medium is 3.5 or higher;

ii) at least a portion of said acid inhibitor 

is not surrounded by an enteric coating 

and, upon ingestion of said unit dosage 

form by said patient, is released regardless 

of whether the pH of the surrounding medium is below 3.5 or above 3.5.

’907 patent col. 20 ll. 9–32.

1. A pharmaceutical composition in unit dosage 

form comprising therapeutically effective amounts 

of:

(a) esomeprazole, wherein at least a portion of said esomeprazole is not surrounded 

by an enteric coating; and

(b) naproxen surrounded by a coating that 

inhibits its release from said unit dosage 

form unless said dosage form is in a medium with a pH of 3.5 or higher;

wherein said unit dosage form provides for release 

of said esomeprazole such that upon introduction 

of said unit dosage form into a medium, at least a 

portion of said esomeprazole is released regardless 

of the pH of the medium.

’285 patent col. 22 ll. 9–19.

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The shared specification discloses that the invention “is 

directed to a pharmaceutical composition in unit dosage 

form suitable for oral administration to a patient” that 

“contains an acid inhibitor present in an amount effective 

to raise the gastric pH of a patient to at least 3.5, preferably 

to at least 4, and more preferably to at least 5, when one or 

more unit dosage forms are administered.” ’907 patent col. 

3 ll. 19–25.1 It discloses exemplary acid inhibitors like 

PPIs, which the patents teach includes omeprazole and 

esomeprazole. It recites amounts of omeprazole between 5 

and 50 mg and amounts of esomeprazole between 5 and 100 

mg, “with about 40 mg per unit dosage form being preferred.” Id. at col. 7 ll. 9–13. The specification discloses 

that “[t]he pharmaceutical composition also contains a nonsteroidal anti-inflammatory drug in an amount effective to 

reduce or eliminate pain or inflammation.” Id. at col. 3 ll. 

39–41. It provides that “[t]he most preferred NSAID is 

naproxen in an amount of between 50 mg and 1500 mg, and 

more preferably, in an amount of between 200 mg and 600 

mg.” Id. at col. 3 ll. 48–50.

The specification teaches methods for preparing and 

making the claimed drug formulations, including in tablet 

dosage forms. It provides examples of the structure and 

ingredients of the drug formulations that comport with the 

invention. It is undisputed that there is no experimental 

data demonstrating the therapeutic effectiveness of any 

amount of uncoated PPI and coated NSAID in a single dosage form. Appellant’s Opening Br. 23, 33; Appellee’s Resp. 

Br. 35, 43; Oral Arg. at 34:08–40, http://oralarguments.cafc.uscourts.gov/default.aspx?fl=2017-2473.mp3. 

Furthermore, although the specification expressly provides 

that PPIs are “enteric coated to avoid destruction by 

 

1 Because the ’907 and ’285 patents have nearly 

identical specifications, we cite to the ’907 patent only unless stated otherwise.

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stomach acid,” there is no alternative disclosure explaining 

that uncoated PPI could still be effective to raise pH. ’907 

patent col. 2 l.6; Oral Arg. at 34:08–39:28.

Pozen ultimately sold its rights to the ’907 and ’285 patents to Nuvo Pharmaceuticals, and Horizon Pharma

maintained its previously obtained license under those patents. Nuvo makes and sells a drug called Vimovo®, which 

is a commercial embodiment of the ’907 and ’285 patents. 

The Generics want to market a generic version of Vimovo®. 

They submitted Abbreviated New Drug Applications (“ANDAs”) to the U.S. Food and Drug Administration (“FDA”) 

seeking approval to market products covered by the claims 

of the ’907 and ’285 patents. Dr. Reddy’s also submitted a 

second ANDA covering a product slightly different than 

Vimovo® because it contains a small amount of uncoated 

NSAID in the outer layer of the tablet, which is separate 

from the enteric-coated NSAID that releases only when the 

pH rises to about 5.5.

II

Nuvo sued the Generics in the United States District 

Court for the District of New Jersey to prevent their ANDA 

products from going to market, if approved, before the expiration of the ’907 and ’285 patents. Nuvo alleged that all 

the Generics’ ANDA products will infringe claims 5, 15, 52, 

and 53 of the ’907 patent and claims 1–4 of the ’285 patent.2 

The Generics stipulated to infringement, except with respect to Dr. Reddy’s second ANDA product, which it alleged 

will not infringe the claims of either patent. The Generics 

defended against the infringement assertions by alleging 

that the asserted patents are invalid as obvious over the 

prior art under 35 U.S.C. § 103 and for lack of enablement 

and an adequate written description under 35 U.S.C. § 112.

 

2 All the asserted claims of the ’907 and ’285 patents 

are dependent on claim 1 of those respective patents.

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Dr. Reddy’s moved for summary judgment of noninfringement, arguing that its second ANDA product does not 

infringe the asserted claims of the ’907 patent. It argued 

that, because the claims of the ’907 patent prevent “essentially any NSAID” from being released from the unit dosage form until the pH reaches at least 3.5, its second ANDA 

product containing some amount of NSAID in the outer 

layer that is released immediately, regardless of the pH,

cannot infringe those claims. Nuvo countered that the 

phrase “essentially any NSAID” in the claim language prevents only NSAID in the core of the tablet from being released before the pH rises to 3.5 or higher and that the 

claimed invention allows for a small amount of additional 

NSAID to be released immediately. The district court 

agreed with Dr. Reddy’s and granted its summary judgment motion.

The court then held a six-day bench trial on the validity 

of the ’907 and ’285 patents, as well as Dr. Reddy’s contention that its second ANDA product does not infringe the 

asserted claims of the ’285 patent. It concluded that none

of the asserted claims are obvious over the prior art because it was nonobvious to use a PPI to prevent NSAIDrelated gastric injury, and persons of ordinary skill in the 

art were discouraged by the prior art from using uncoated 

PPI and would not have reasonably expected it to work. It 

also determined that the asserted claims of both patents 

are enabled because the specification teaches how to make 

and use the invention and expert testimony demonstrated 

that an ordinarily skilled artisan would have accepted the 

usefulness of an NSAID–PPI combination therapy for 

treating pain.

The district court went on to reject all three of the Generics’ written description arguments. First, the court rejected the “comprising” written description argument. The 

Generics argued that, because of the “comprising” language in the ’285 patent’s claims, they allow for the drug 

formulation to include some uncoated naproxen that is 

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released immediately regardless of the pH, which is not 

supported by the specification and goes against the concept 

of coordinated release that is at the heart of the patent’s 

invention. The court disagreed because it viewed uncoated 

naproxen as a less preferred embodiment of the claimed invention and thus found that the invention was supported 

by the general disclosure in the specification.

Second, the district court rejected the “inhibit” written 

description argument. The Generics contended that, although the patent discloses only delayed release formulations, the claims of the ’285 patent recite a broader 

undescribed invention, namely sustained release as opposed to coordinated release of naproxen. That is because 

the claims cover any formulation having a coating that 

merely “inhibits” the release of naproxen before the pH 

reaches 3.5 or higher, which would include sustained release drugs that immediately discharge naproxen albeit at 

a slower rate than is typical. The court disagreed that the 

word “inhibits” meant that the claims contemplated sustained release drug formulations and thus concluded that 

the claims do not lack written description support on that 

basis.

Third, the district court rejected the “efficacy” written 

description argument. The Generics argued that, if they 

lose on their obviousness contention, then the claims lack 

written description support for the claimed effectiveness of 

uncoated PPI because ordinarily skilled artisans would not 

have expected it to work and the specification provides no 

experimental data or analytical reasoning showing the inventor possessed an effective uncoated PPI. Nuvo responded that experimental data and an explanation of why 

an invention works are not required, the specification adequately describes using uncoated PPI, and its effectiveness 

is necessarily inherent in the described formulation. The 

court rejected the notion that effectiveness does not need to 

be described because it is necessarily inherent in the 

claimed drug formulation. It also held that the 

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specification of the ’907 and ’285 patents did not disclose 

information regarding the efficacy of uncoated PPI. But 

the court nonetheless concluded that the claims were adequately described because the specification described the 

immediate release of uncoated PPI and the potential disadvantages of coated PPI, namely that enteric-coated PPI 

sometimes works too slowly to raise the intragastric pH. 

The district court did not explain why the mere disclosure 

of immediate release uncoated PPI, coupled with the 

known disadvantages of coated PPI, is relevant to the therapeutic effectiveness of uncoated PPI, which the patent itself recognized as problematic for efficacy due to its 

potential for destruction by stomach acid.

Finally, the district court held that Dr. Reddy’s second 

ANDA product infringes the claims of the ’285 patent because it satisfies all the limitations recited in those claims.

The Generics now appeal the first “comprising” and 

third “efficacy” written description rulings. They do not appeal the obviousness holding, the enablement decision, or 

the second “inhibit” written description issue. Nuvo crossappeals the district court’s grant of summary judgment of 

noninfringement. We have jurisdiction to decide the appeals under 28 U.S.C. § 1295(a)(1).

DISCUSSION

The Generics’ appeal and Nuvo’s cross-appeal present 

three main issues. First, the Generics argue that the district court clearly erred when it concluded that the specification of the ’907 and ’285 patents adequately describes the 

claimed effectiveness of uncoated PPI. The Generics emphasize the circumstances in which the written description 

issue arises in this case. The asserted claims recite the 

therapeutic effectiveness of uncoated PPI, but the prior art 

taught away from such effectiveness. In those circumstances, the Generics argue that satisfaction of the written 

description requirement requires either supporting experimental data, or some reason, theory, or alternative 

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explanation as to why the claimed invention is possessed 

by the inventor, and that mere recitation of claim language 

in the specification cannot suffice. Second, the Generics 

argue that the district court clearly erred when it concluded that the specification of the ’907 and ’285 patents 

adequately describes uncoated naproxen. Finally, Nuvo argues that the district court should not have granted summary judgment of noninfringement in favor of Dr. Reddy’s 

because it incorrectly construed the term “essentially any 

NSAID” in the claims of the ’907 patent to prevent even 

small amounts of uncoated NSAID in the unit dosage form.

Whether a claim satisfies the written description requirement is a question of fact. Allergan, Inc. v. Sandoz 

Inc., 796 F.3d 1293, 1308 (Fed. Cir. 2015). Therefore, on 

appeal from a bench trial, we review a written description 

determination for clear error. Id. “Under the clear error 

standard, the court’s findings will not be overturned in the 

absence of a ‘definite and firm conviction’ that a mistake 

has been made.” Scanner Techs. Corp. v. ICOS Vision Sys. 

Corp. N.V., 528 F.3d 1365, 1374 (Fed. Cir. 2008) (quoting 

Pfizer, Inc. v. Teva Pharm. USA, Inc., 518 F.3d 1353, 1366 

(Fed. Cir. 2008)).

Our analysis begins and ends with the “efficacy” written description issue.

I

The written description requirement of 35 U.S.C. 

§ 112, ¶ 1 provides, in pertinent part, that “[t]he specification shall contain a written description of the invention.”3 

That requirement is satisfied only if the inventor “convey[s] 

 

3 Because the applications resulting in the ’907 and 

’285 patents were filed before the enactment of the Leahy–

Smith America Invents Act (“AIA”), Pub. L. No. 112–29, 

§ 4(c), 125 Stat. 284, 296–97 (2011), we apply the pre-AIA 

version of 35 U.S.C. § 112.

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with reasonable clarity to those skilled in the art that, as 

of the filing date sought, he or she was in possession of the 

invention,’ and demonstrate[s] that by disclosure in the 

specification of the patent.” Centocor Ortho Biotech, Inc. v. 

Abbott Labs., 636 F.3d 1341, 1348 (Fed. Cir. 2011) (quoting 

Carnegie Mellon Univ. v. Hoffmann–La Roche Inc., 541 

F.3d 1115, 1122 (Fed. Cir. 2008)). “The essence of the written description requirement is that a patent applicant, as 

part of the bargain with the public, must describe his or her 

invention so that the public will know what it is and that 

he or she has truly made the claimed invention.” AbbVie 

Deutschland GmbH & Co. v. Janssen Biotech, Inc., 759 

F.3d 1285, 1298 (Fed. Cir. 2014).

The Generics argue that the district court clearly erred 

when it concluded that the claimed effectiveness of uncoated PPI in the ’907 and ’285 patents is supported by adequate written description. Their argument is 

straightforward. The ’907 and ’285 patents claim uncoated 

PPI effective to raise the gastric pH to at least 3.5, the district court found upon Nuvo’s insistence as part of its obviousness analysis that ordinarily skilled artisans would not 

have expected uncoated PPIs to be effective, and nothing in 

the specification would teach a person of ordinary skill in 

the art otherwise.

Nuvo counters that the district court correctly concluded that the claimed uncoated PPI is supported by adequate written description. It argues that the claims do not 

require any particular degree of efficacy of the uncoated 

PPI itself, it is enough that the specification discloses making and using drug formulations containing effective 

amounts of PPI and NSAID, and experimental data and 

additional explanations demonstrating the invention 

works are unnecessary.

The district court held that the Generics failed to prove 

by clear and convincing evidence that the asserted claims 

of the ’907 and ’285 patents are invalid for lack of written 

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description. But its analysis does not support its conclusion. The district court, after finding that the specification 

lacks “information regarding the efficacy of uncoated 

PPIs,” said it was enough that the specification described 

the immediate release of uncoated PPI and the potential 

disadvantages of enteric-coated PPI formulations. J.A. 82–

83. But that disclosure it pointed to in no way provides 

support for the claimed efficacy of uncoated PPI. Even if 

the district court thought that it was enough that the patents taught how to make and use drug formulations containing uncoated PPI, it flatly rejected Nuvo’s argument 

“that the efficacy of uncoated PPIs need not be described 

because it is ‘necessarily inherent’ in a formulation.” J.A. 

83. Nevertheless, because we review the district court’s decision for clear error, we will scour the record created below 

for evidence supporting the district court’s written description finding.

A

At trial, the parties and the district court understood 

that the plain words of the patents claim effectiveness of 

uncoated PPI. Beyond the plain language of the claims, the 

district court was not asked to define further the effectiveness limitation. The parties and the district court also understood that written description of effective uncoated PPI 

is required. Nuvo nonetheless for the first time on appeal, 

and as its lead argument, contends that we can affirm the 

district court’s written description finding because the 

claims do not recite an efficacy requirement for uncoated 

PPI. The Generics of course disagree. We read Nuvo’s appellate brief as presenting at least five arguments aimed at 

either recharacterizing the written description dispute or 

rewriting the claim language. We reject them all as meritless.

Claim 1 of the ’907 patent recites “[a] pharmaceutical 

composition in unit dosage form suitable for oral administration to a patient, comprising: . . . an acid inhibitor 

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present in an amount effective to raise the gastric pH of said 

patient to at least 3.5 upon the administration of one or 

more of said unit dosage forms” and wherein “at least a 

portion of said acid inhibitor is not surrounded by an enteric coating . . . .” ’907 patent col. 20 ll. 9–29 (emphasis 

added). Claim 1 of the ’285 patent recites “[a] pharmaceutical composition in unit dosage form comprising therapeutically effective amounts of: (a) esomeprazole, wherein at 

least a portion of said esomeprazole is not surrounded by 

an enteric coating” and “wherein said unit dosage form provides for release of said esomeprazole such that upon introduction of said unit dosage form into a medium, at least a 

portion of said esomeprazole is released regardless of the 

pH of the medium.” ’285 patent col. 22 ll. 9–19 (emphasis 

added). The claim also recites “naproxen surrounded by a 

coating that inhibits its release from said unit dosage form 

unless said dosage form is in a medium with a pH of 3.5 or 

higher,” which means the esomeprazole must be acting to 

raise the pH to effect the release of the naproxen from the 

dosage form. Id. at col. 22 ll. 13–15. Both patents-in-suit 

therefore recite claims requiring amounts of uncoated PPI 

effective to raise the gastric pH to at least 3.5. No argument was made below that the claims of the ’907 patent 

should be treated any differently than those of the ’285 patent with respect to the efficacy limitation. And the district 

court treated the claims the same with respect to that limitation. So we do not treat them differently on appeal either.

First, Nuvo argues that there is no requirement that 

the dosage form as a whole be effective to raise the gastric 

pH. While we agree, we do not understand the Generics to 

be arguing that the claims require the entire drug to be effective to raise the gastric pH to a certain level. Instead, 

the uncoated PPI must effectively do so.

Second, Nuvo contends that the claims do not require 

an effective amount of the combined uncoated PPI and 

coated naproxen in a single dosage form, but only amounts 

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of each component effective on their own. The Generics respond that Nuvo’s argument is divorced from the claim as 

a whole, which requires coordinated release achieved by an 

effective amount of uncoated PPI that raises the gastric pH 

to at least 3.5 and an effective amount of naproxen that is 

released to treat pain when the pH reaches the desired 

level. Nuvo’s argument was not raised below and thus is 

forfeited. See TVIIM, LLC v. McAfee, Inc., 851 F.3d 1356, 

1363 (Fed. Cir. 2017) (“[A] party may not introduce new 

claim construction arguments on appeal or alter the scope 

of the claim construction positions it took below. Moreover, 

litigants waive their right to present new claim construction disputes if they are raised for the first time after 

trial.”).

Third, Nuvo argues that the claims do not require that 

the uncoated PPI be effective to raise the gastric pH to a 

certain level, but only that the dosage forms contain an effective amount of uncoated PPI. The Generics disagree. 

Nuvo forfeited the argument by not raising it below. Additionally, it is nonsensical to read the claims to require effective amounts of uncoated PPI without specifying the 

result effectively achieved. Claim 1 of the ’907 patent expressly states that the PPI, which is uncoated, must be effective to raise the gastric pH to at least 3.5. Claim 1 of the 

’285 patent at least impliedly requires the same since the 

naproxen is only released when the pH reaches at least 3.5 

and the uncoated esomeprazole is the only other agent 

available in the dosage form to achieve that goal.

Fourth, Nuvo contends that the ’907 patent allows multiple dosage forms rather than a single dosage form to satisfy any perceived efficacy requirement, so the specification 

does not need to show an effective amount of uncoated PPI 

in one dosage form. We disagree. As stated above, Nuvo 

forfeited any argument that the ’907 and ’285 patents 

should be treated differently with respect to the efficacy requirement by not raising it to the district court. And the 

’285 patent does not allow for more than one dosage form. 

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Even if it were true that the ’907 patent allows more than 

one dosage form to effectively raise the gastric pH to at 

least 3.5 using uncoated PPI, the specification would still 

need to provide support for the notion that uncoated PPI is 

effective.

Last, Nuvo argues that the Examiner interpreted the 

’907 patent claims as merely requiring certain amounts of 

PPI and NSAID effective on their own rather than requiring an overall efficacy for the combined drug. The Generics 

counter that the Examiner never considered the effectiveness of uncoated PPI because it was not a claim limitation 

at the time of the initial rejection. We already rejected 

Nuvo’s argument that the difference between a dosage 

form as a whole containing an effective amount of uncoated 

PPI and an effective amount of uncoated PPI as a component meaningfully impacts the written description analysis. And we also already rejected its argument that the 

Generics were contending that Nuvo had to demonstrate 

the overall effectiveness of the entire drug combination. 

Furthermore, the argument is forfeited because it was not 

presented below. Finally, the Examiner appears to have 

interpreted the claims to require an amount of PPI, 

whether coated or uncoated, effective to raise the gastric 

pH to the desired level. We agree with that understanding 

and written description support must be provided for that 

limitation.

In sum, the parties appear to have assumed before the 

district court that the claims require a therapeutically effective amount of uncoated PPI that can raise the gastric 

pH to at least 3.5. We see no reason to change course on 

appeal. Because the parties’ assumption at the trial court 

is a fair reading of the claim language, we will proceed as 

everyone did before the district court and search the specification for written description support for the efficacy of 

uncoated PPI.

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B

Nuvo argues that credible expert testimony from its 

witness, Dr. Williams, identified written description support in the specification for the claimed dosage forms comprising an effective amount of uncoated PPI. Specifically, 

Nuvo points to Dr. Williams’s testimony that every limitation of the asserted claims in the ’907 and ’285 patents has 

adequate written description support in the shared specification.

Dr. Williams identified four parts of the specification 

that he thought provide written description support for

amounts of uncoated PPI, and specifically esomeprazole, 

effective to raise the gastric pH of a patient to at least 3.5. 

He pointed to the specification’s statement that “[t]he composition contains an acid inhibitor present in an amount 

effective to raise the gastric pH of a patient to at least 3.5.” 

See J.A. 10787 (quoting ’907 patent col. 3 ll. 21–23), 10797

(similar). He also pointed to the claims themselves for 

written description support. See J.A. 10787 (citing ’907 patent col. 20 ll. 9–32, 42–45), 10798 (similar). He then said 

the sixth example in the specification provides support for 

uncoated PPI because it includes “omeprazole immediate 

release” in the title and provides that a layer of the composition embodied in the example “contains an acid inhibitor 

in an effective amount which is released from the dosage 

form as soon as the film coat dissolves,” where the acid inhibitor is the PPI omeprazole. J.A. 10788–89 (quoting ’907 

patent col. 14 ll. 40–41, col. 15 ll. 1–3). His last piece of 

support from the specification was its statement that 

“[p]roton pump inhibitors will typically be present at about 

5 milligrams to 600 milligrams per dose” and “[e]someprazole is 5 to 100 milligrams.” J.A. 10798 (quoting ’907 patent col. 7 ll. 7–13).

The Generics argue that the parts of the specification 

Dr. Williams identified are not enough to satisfy the written description requirement. They argue that the 

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specification provides only typical dosage amounts of uncoated PPI and the use of uncoated PPI in a drug formulation, but it never discusses or explains its efficacy. We 

agree with the Generics that Dr. Williams’s testimony does 

not identify parts of the specification sufficient to satisfy 

the written description requirement. The statements he 

points to recite the claim limitation by simply calling generally for effective amounts of uncoated PPI, but our precedent clearly establishes that is not enough.

We have expressly rejected the “argument that the 

written description requirement . . . is necessarily met as a 

matter of law because the claim language appears in ipsis 

verbis in the specification.” Enzo Biochem, Inc. v. Gen–

Probe Inc., 323 F.3d 956, 968 (Fed. Cir. 2002). We explained that “[t]he appearance of mere indistinct words in 

a specification or a claim, even an original claim, does not 

necessarily satisfy” § 112, ¶ 1 because it may not both put 

others on notice of the scope of the claimed invention and 

demonstrate possession of that invention. Id. at 968–69.

It is true that our case law does not require experimental data demonstrating effectiveness. Allergan, 796 

F.3d at 1309; see also In re ’318 Patent Infringement Litig., 

583 F.3d 1317, 1324 (Fed. Cir. 2009) (“Typically, patent applications claiming new methods of treatment are supported by test results. But it is clear that testing need not 

be conducted by the inventor.”). It also does not require 

theory or explanation of how or why a claimed composition 

will be effective. Allergan, 796 F.3d at 1308–09. Moreover, 

we have repeatedly stated that the invention does not actually have to be reduced to practice. Univ. of Rochester v. 

G.D. Searle & Co., 358 F.3d 916, 926 (Fed. Cir. 2004).

Nevertheless, as the Generics point out and Nuvo cannot reasonably dispute, the record evidence demonstrates 

that a person of ordinary skill in the art would not have 

known or understood that uncoated PPI is effective. And 

there is nothing in the specification of the patents-in-suit 

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showing “that the inventor actually invented the invention 

claimed.” Centocor, 636 F.3d at 1348 (emphasis added); accord Ariad Pharm., Inc. v. Eli Lilly & Co., 598 F.3d 1336, 

1351 (Fed. Cir. 2010) (en banc). There must be some description, such as a constructive reduction to practice, establishing that the inventor “was in possession of the . . . 

claimed invention, including all of the elements and limitations.” Univ. of Rochester, 358 F.3d at 926 (quoting Hyatt 

v. Boone, 146 F.3d 1348, 1353 (Fed. Cir. 1998)). Patents 

are not rewarded for mere searches, but are intended to 

compensate their successful completion. Ariad, 598 F.3d 

at 1353. That is why the written description requirement 

incentivizes “actual invention,” id., and thus “[a] ‘mere 

wish or plan’ for obtaining the claimed invention is not adequate written description,” Centocor, 636 F.3d at 1348

(quoting Regents of the Univ. of Cal. v. Eli Lilly & Co., 119 

F.3d 1559, 1566 (Fed. Cir. 1997)).

In light of the fact that the specification provides nothing more than the mere claim that uncoated PPI might 

work, even though persons of ordinary skill in the art 

would not have thought it would work, the specification is 

fatally flawed. It does not demonstrate that the inventor 

possessed more than a mere wish or hope that uncoated 

PPI would work, and thus it does not demonstrate that he 

actually invented what he claimed: an amount of uncoated

PPI that is effective to raise the gastric pH to at least 3.5. 

That conclusion is confirmed by the inventor’s, Dr. 

Plachetka’s, own testimony at trial during which he admitted that he only had a “general concept of coordinated delivery with acid inhibition” using uncoated PPI at the time 

he filed his first patent application. J.A. 9942, 10000–01. 

Although Dr. Plachetka said he thought he “put a rationale 

in [the specification] as to why [uncoated PPI] would work,” 

he did not identify any particular part of the specification 

supporting that understanding. J.A. 9997. And his only 

support in the specification for “a rationale explaining why 

[he] thought the uncoated PPI would be effective for 

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treating gastric related injury” was that, in its “entire context,” he explained “why the coordinated delivery system 

would be of benefit for patients.” Id. Although inventor 

testimony cannot establish written description support 

where none exists in the four corners of the specification, it 

illuminates the absence of critical description in this case.4

C

Nuvo’s final arguments are that it is enough to satisfy 

the written description requirement that the specification 

of the ’907 and ’285 patents teaches how to make and use 

the claimed invention, and that we should accept the therapeutic effectiveness of uncoated PPI as a matter of 

 

4 At oral argument, Nuvo also encouraged us to find 

written description support for the therapeutic effectiveness of uncoated PPI based on testimony of Dr. Kibbe, the 

Generics’ expert. Oral Arg. at 50:51–52:26. But in that 

part of the trial transcript Nuvo directed us to, Dr. Kibbe 

only discussed what the patent claims require and he never 

testified about the written description support in the specification for the efficacy of uncoated PPI. Furthermore, although Dr. Kibbe later confirmed during his trial testimony 

that he thought “an enteric-coated NSAID surrounded by 

an uncoated PPI would be effective for treating chronic 

pain,” his confirmation was ambiguous because he qualified it with “I think I have got that right. I’m not sure.” 

J.A. 10513. Even if we accepted his statement that uncoated PPI would be effective for treating chronic pain, the 

district court rejected the notion that ordinarily skilled artisans would have used uncoated PPI in its obviousness 

analysis, and his testimony only speaks to treating pain 

and not to raising the gastric pH to at least 3.5. Dispositively, Dr. Kibbe’s testimony is irrelevant to the written description inquiry, because it does not point to any 

disclosure in the specification to which the testimony could 

relate.

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inherency. The Generics respond that Nuvo is wrong because that only satisfies the enablement requirement, 

which is separate and distinct from the written description 

requirement. As for inherency, the Generics note that the 

district court rejected that ground for written description 

support, and assert that Nuvo has not made out a case for 

inherent disclosure.

1.

Teaching how to make and use an invention does not 

necessarily satisfy the written description requirement. 

We have recognized that the enablement requirement, 

which requires the specification to teach those skilled in 

the art how to make and use the claimed invention without 

undue experimentation, is separate and distinct from the 

written description requirement. Ariad, 598 F.3d at 1343–

51. And the fact that an invention may be enabled does not 

mean it is adequately described, and vice versa. Univ. of 

Rochester, 358 F.3d at 921–22. That is because “[t]he purpose of the written description requirement is broader than 

to merely explain how to ‘make and use’ [the invention].” 

Id. at 920. The focus of the written description requirement is instead on whether the specification notifies the 

public about the boundaries and scope of the claimed invention and shows that the inventor possessed all the aspects of the claimed invention. Id. at 926.

Nuvo cites our decision in Alcon Research Ltd. v. Barr 

Laboratories, Inc., 745 F.3d 1180 (Fed. Cir. 2014), to support its position that it is enough that the patents teach 

making and using the claimed combination drug formulation. The Generics argue that case is distinguishable. We 

agree that Alcon does not save the claims of the ’907 and 

’285 patents.

In Alcon, patent claims were directed to a method for 

enhancing the chemical stability of an aqueous solution 

containing a therapeutically effective amount of a known 

drug. 745 F.3d at 1184. We held that the claims were 

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adequately described because the disclosure in the specification demonstrated that the inventor possessed and actually invented the claimed stability enhancing features of 

the method. Id. at 1191. We noted that the patent referenced the unexpected nature of the discovery, gave exemplary formulations, and disclosed data showing stability 

testing using the claimed invention. Id.

The factual circumstances in Alcon are markedly different than the facts presented here. Unlike the specification of the patent at issue in Alcon, the specification of the 

’907 and ’285 patents does not provide any data showing 

that uncoated PPI is effective in raising the gastric pH of a 

patient to at least 3.5. Even though we said in Alcon that

“written description is about whether the skilled reader of 

the patent disclosure can recognize that what was claimed 

corresponds to what was described” and “is not about 

whether the patentee has proven to the skilled reader that 

the invention works, or how to make it work,” we found 

that the written description requirement was satisfied at 

least in part by accelerated stability testing data showing 

the claimed effect. Id. Under those circumstances, it was 

not necessary for the patentee to demonstrate or otherwise 

“prove” beyond the data disclosed in the specification that 

the invention works. Here, there is no similar hook or disclosure in the specification that an ordinarily skilled artisan can rely on to understand that the inventor possessed 

effective uncoated PPI.

2.

Our case law has recognized that, under a narrow set 

of circumstances, the written description requirement may 

be satisfied without an explicit disclosure if the claimed 

features are necessarily inherent in what is expressly described. See, e.g., Allergan, 796 F.3d at 1309 (“A claim that 

recites a property that is necessarily inherent in a formulation that is adequately described is not invalid as lacking 

written description merely because the property itself is 

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not explicitly described.”); Yeda Research & Dev. Co. v. Abbott GmbH & Co. KG, 837 F.3d 1341, 1345 (Fed. Cir. 2016) 

(“Under the doctrine of inherent disclosure, when a specification describes an invention that has certain undisclosed 

yet inherent properties, that specification serves as adequate written description to support a subsequent patent 

application that explicitly recites the invention’s inherent 

properties.”); cf. Manual of Patent Examining Procedure 

§ 2163 (9th ed. Rev. 3, Jan. 2018) (recognizing that inherency may satisfy the written description requirement).

Nuvo cites our decision in Allergan to support its position that the claimed efficacy of uncoated PPI is necessarily 

inherent in the specification’s explicit disclosure of methods for making and using drug formulations containing uncoated PPI. The Generics contend that, like Alcon, 

Allergan is also factually distinguishable. We agree.

In Allergan, the patentee claimed a drug combination 

effective for reducing intraocular pressure that included 

0.01% bimatoprost and 200 ppm benzalkonium chloride 

(“BAK”). 796 F.3d at 1300. But the prior art taught away 

from the claimed combination of ingredients and the specification did not explicitly describe its clinical efficacy. Id.

at 1298, 1305–07, 1309. While we upheld the nonobviousness of the claimed invention given the unexpected results 

of and teaching away from increasing the amount of BAK 

to decrease the amount of intraocular pressure, we also 

held that the claims were supported by adequate written 

description. Id. at 1305, 1309. We reasoned that the parties did not dispute that “the inherent properties of a formulation comprising 0.01% bimatoprost and 200 ppm BAK 

produce the claimed clinical profile.” Id. at 1309. It was 

enough that the specification described the formulation, its 

components, and how to make and use it. Id. at 1308–09. 

Moreover, there were experimental results for similar drug 

formulations demonstrating a trend in their clinical effectiveness, even if the data were not specifically related to 

the exact formulation claimed. Id. at 1299–300.

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Here, unlike in Allergan, whether uncoated PPI is inherently effective in raising the gastric pH to at least 3.5 is 

disputed. And there is no written disclosure that in any 

way relates to the efficacy of immediately released PPI. 

Neither party has identified any evidence in the record that 

uncoated PPI necessarily is effective in a certain amount, 

consistent with the specification, to raise the gastric pH to 

3.5 or higher. Nor can we find any evidence in the record 

demonstrating the inherency of the claimed feature. That 

failure of proof thus dooms Nuvo’s inherency argument.

D

Written description analyses are highly fact specific. 

See Amgen Inc. v. Sanofi, 872 F.3d 1367, 1377 (Fed. Cir. 

2017) (“[E]ach case involving the issue of written description must be decided on its own facts.” (alterations and internal quotation marks omitted) (quoting Noelle v. 

Lederman, 355 F.3d 1343, 1349 (Fed. Cir. 2004))); Vas–

Cath Inc. v. Mahurkar, 935 F.2d 1555, 1562 (Fed. Cir. 

1991) (“The CCPA’s ‘written description’ cases often 

stressed the fact-specificity of the issue.”). Based on the 

specific facts of certain cases, it is unnecessary to prove 

that a claimed pharmaceutical compound actually achieves 

a certain result. But when the inventor expressly claims 

that result, our case law provides that that result must be 

supported by adequate disclosure in the specification. In 

this case, the inventor chose to claim the therapeutic effectiveness of uncoated PPI, but he did not adequately describe the efficacy of uncoated PPI so as to demonstrate to 

ordinarily skilled artisans that he possessed and actually 

invented what he claimed. And the evidence demonstrates 

that a person of ordinary skill in the art reading the specification would not have otherwise recognized, based on the 

disclosure of a formulation containing uncoated PPI, that 

it would be efficacious because he or she would not have 

expected uncoated PPI to raise gastric pH. Under those 

facts, the patent claims are invalid for lack of adequate 

written description pursuant to § 112, ¶ 1.

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II

Because we hold that the ’907 and ’285 patents are invalid for lack of an adequate written description given that 

the shared specification does not adequately describe the 

claimed effectiveness of uncoated PPI, we do not need to 

address the Generics’ alternative argument that the patents are also invalid under § 112, ¶ 1 for failing to adequately describe uncoated, immediate release naproxen. 

Similarly, because we conclude that the asserted claims are 

invalid, Nuvo’s cross-appeal challenging the district court’s 

grant of summary judgment of noninfringement with respect to Dr. Reddy’s second ANDA product and the ’907 patent is moot.

CONCLUSION

For the reasons stated above, we reverse the district 

court’s determination that the asserted claims of the ’907 

and ’285 patents are not invalid for lack of an adequate 

written description. Those claims are invalid. We dismiss 

as moot Nuvo’s cross-appeal challenging the district court’s 

grant of summary judgment of noninfringement to Dr. 

Reddy’s with respect to its second ANDA product and the 

now-invalidated ’907 patent claims.

REVERSED AS TO 17-2473, 17-2481, 17-2484, 17-

2486; DISMISSED AS TO 17-2489, 17-2491, 17-2492, 

17-2493.

COSTS

No costs.

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