Source: s3://data.kl3m.ai/documents/govinfo/USCOURTS/USCOURTS-ca13-15-01902/USCOURTS-ca13-15-01902-0/pdf.json

Nature of Suit Code: 830
Nature of Suit: Patent
Cause of Action: 

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United States Court of Appeals 

for the Federal Circuit ______________________ 

INTENDIS GMBH, INTRASERV GMBH & CO. KG, 

BAYER HEALTHCARE PHARMACEUTICALS INC.,

Plaintiffs-Appellees

v.

GLENMARK PHARMACEUTICALS INC., USA, 

GLENMARK PHARMACEUTICALS LTD.,

Defendants-Appellants

______________________ 

2015-1902

______________________ 

Appeal from the United States District Court for the 

District of Delaware in No. 1:13-cv-00421-SLR, Judge Sue

L. Robinson.

______________________ 

Decided: May 16, 2016

______________________ 

BRADFORD J. BADKE, Sidley Austin LLP, New York, 

NY, argued for plaintiffs-appellees. Also represented by 

SONA DE. 

WILLIAM M. JAY, Goodwin Procter LLP, Washington, 

DC, argued for defendants-appellants. Also represented 

by BRIAN TIMOTHY BURGESS; ELIZABETH HOLLAND, LINNEA 

P. CIPRIANO, HUIYA WU, New York, NY; DAVID ZIMMER, 

San Francisco, CA.

______________________ 

Case: 15-1902 Document: 56-2 Page: 1 Filed: 05/16/2016
2 INTENDIS GMBH v. GLENMARK PHARMACEUTICALS INC. 

Before PROST, Chief Judge, MOORE and TARANTO, Circuit Judges.

MOORE, Circuit Judge.

This case arises under the Hatch–Waxman Act,1 and 

involves Glenmark Pharmaceuticals Ltd. and Glenmark 

Pharmaceuticals Inc., USA’s (collectively, “Glenmark”) 2

proposed generic version of Finacea® Gel, a topical medication for various skin disorders. Glenmark appeals the 

United States District Court for the District of Delaware’s 

final judgment entered in favor of Intendis GmbH, Intraserv GmbH & Co. KG, and Bayer HealthCare Pharmaceuticals Inc. (collectively, “Appellees”). For the reasons 

set forth below, we affirm. 

BACKGROUND

Appellee Bayer HealthCare Pharmaceuticals Inc. 

holds approved New Drug Application (“NDA”) No. 21470 

for Finacea® Gel, which contains azelaic acid as the 

therapeutically active ingredient in a concentration of

15% by weight and is indicated for the topical treatment 

of inflammatory papules and pustules of mild to moderate 

rosacea. Finacea® Gel’s inactive ingredients, known as 

excipients, include triglycerides and lecithin. Finacea® 

Gel is manufactured in the form of a “hydrogel,” which the 

 

1 The Hatch–Waxman Act is the name commonly 

used to refer to the Drug Price Competition and Patent 

Term Restoration Act of 1984, Pub. L. No. 98–417, 98 

Stat. 1585 (1984) (codified in relevant part at 21 U.S.C. § 

355), as amended, which governs the Food and Drug 

Administration’s approval of new and generic drugs. 2 Glenmark Pharmaceuticals Ltd. and Glenmark 

Pharmaceuticals Inc., USA were formerly known as 

Glenmark Generics Ltd. and Glenmark Generics Inc., 

USA, respectively.

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INTENDIS GMBH v. GLENMARK PHARMACEUTICALS INC. 3

district court construed to mean “a semisolid dosage form 

that contains water and a gelling agent to form a gel, 

which may contain dispersed particles and/or insoluble 

liquids.” Intendis GmbH v. Glenmark Pharm. Ltd., 117 F. 

Supp. 3d 549, 567–68 (D. Del. 2015). 

The Food and Drug Administration’s (“FDA”) Approved Drug Products with Therapeutic Equivalence 

Evaluation, commonly known as the Orange Book, lists 

U.S. Patent No. 6,534,070 (“the ’070 patent”) as covering 

Finacea® Gel. The ’070 patent, entitled “Composition 

with Azelaic Acid,” is assigned to Appellee Intraserv 

GmbH & Co. and exclusively licensed to Appellee Intendis 

GmbH. The patent issued in March 2003 and claims 

priority to a provisional application filed on February 12, 

1998. Sole independent claim 1 of the ’070 patent recites: 

1. A composition that comprises:

(i) azelaic acid as a therapeutically active 

ingredient in a concentration of 5 to 20% 

by weight,

(iii) at least one triacylglyceride3 in a concentration of 0.5 to 5% by weight,

(iv) propylene glycol, and

(v) at least one polysorbate, in an aqueous 

phase that further comprises water and 

salts, and the composition further comprises

(ii) at least one polyacrylic acid, and

(vi) lecithin, 

 

3 The parties agree that the claim term “triacylglyceride” means “triglyceride.”

Case: 15-1902 Document: 56-2 Page: 3 Filed: 05/16/2016
4 INTENDIS GMBH v. GLENMARK PHARMACEUTICALS INC. 

wherein the composition is in the form 

of a hydrogel.

’070 patent, col. 6, lines 28–39 (emphases added).

Glenmark Pharmaceuticals Ltd. submitted an Abbreviated New Drug Application (“ANDA”) to the FDA seeking to market a generic version of Finacea® Gel. The 

submission included a paragraph IV certification pursuant to 21 U.S.C. § 355(j)(2)(A)(vii)(IV) asserting that the 

’070 patent is invalid and not infringed. Unlike Finacea® 

Gel, the proposed generic product substituted isopropyl 

myristate for the claimed triglyceride and lecithin. Pursuant to 21 U.S.C. § 505(j)(2)(B)(ii), Glenmark Pharmaceuticals Inc., USA informed Appellees that an ANDA had 

been filed. In response, Appellees filed a complaint 

against Glenmark in the United States District Court for 

the District of Delaware, alleging that Glenmark’s submission of the ANDA infringed the ’070 patent under 35 

U.S.C. § 271(e)(2)(A).

The district court held a Markman hearing on January 21, 2015, and a five-day bench trial from February 5–

11, 2015 on the issues of infringement and validity. On 

July 27, 2015, the district court issued an opinion concluding that claims 1–12 of the ’070 patent were infringed 

under the doctrine of equivalents and not invalid.

With respect to infringement, the central dispute was

whether isopropyl myristate in Glenmark’s generic product met the claim elements triglyceride and lecithin under 

the doctrine of equivalents. The district court found that 

it did, relying on the function-way-result test. The district court rejected Glenmark’s arguments that infringement under the doctrine of equivalents (i) would 

encompass the prior art and (ii) was barred by prosecution history estoppel.

With respect to validity, the district court found that 

none of the prior art references raised by Glenmark 

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INTENDIS GMBH v. GLENMARK PHARMACEUTICALS INC. 5

disclosed every element of independent claim 1 and 

rejected Glenmark’s argument that the claims would have 

been obvious. Prior to Finacea® Gel, Bayer marketed and 

sold a topical 20% azelaic acid cream known as Skinoren®, which is prior art to the ’070 patent. The district 

court agreed with Glenmark that a person of ordinary 

skill in the art would pursue a hydrogel formulation of 

azelaic acid because the Skinoren® formulation had 

undesirable qualities such as phase separation of the 

emulsion, whitening effect, and spreadability problems. 

However, the district court determined that Glenmark 

failed to show by clear and convincing evidence that a 

person of ordinary skill would have been motivated to 

combine the prior art references in a manner that would 

render claim 1 of the ’070 patent obvious. It determined 

that even if Glenmark had, Glenmark failed to show a 

reasonable expectation of success in making such combination. Finally, the district court found that the objective 

indicia of nonobviousness, namely, unexpected results of 

the claimed formulations and commercial success of 

Finacea® Gel, weighed in favor of nonobviousness.

On August 14, 2015, the district court entered a final 

judgment in favor of Appellees and directed the FDA not 

to approve Glenmark’s ANDA until after the November 

18, 2018, expiration of the ’070 patent. This appeal 

followed. 

DISCUSSION

On appeal, Glenmark argues that (i) the district court 

erred in its application of the function prong of the function-way-result test for infringement under the doctrine of 

equivalents, (ii) infringement under the doctrine of equivalents would encompass the prior art, (iii) Appellees 

expressly disavowed and disclaimed a formulation without lecithin, and (iv) the district court erred in its obviousness analysis. We address each argument in turn.

I. Infringement Under the Doctrine of Equivalents

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6 INTENDIS GMBH v. GLENMARK PHARMACEUTICALS INC. 

Infringement under the doctrine of equivalents is a 

question of fact that we review for clear error following a 

bench trial. Allergan, Inc. v. Sandoz Inc., 796 F.3d 1293, 

1311 (Fed. Cir. 2015). Even when an accused product 

does not meet each and every claim element literally, it 

may nevertheless be found to infringe the claim “if there 

is ‘equivalence’ between the elements of the accused 

product or process and the claimed elements of the patented invention.” Warner-Jenkinson Co. v. Hilton Davis 

Chem. Co., 520 U.S. 17, 21 (1997) (quoting Graver Tank & 

Mfg. Co. v. Linde Air Prods. Co., 339 U.S. 605, 609 

(1950)). One way to show equivalence is by showing on an 

element-by-element basis that “the accused product 

performs substantially the same function in substantially 

the same way with substantially the same result as each 

claim limitation of the patented product,” often referred to 

as the function-way-result test. Crown Packaging Tech., 

Inc. v. Rexam Beverage Can Co., 559 F.3d 1308, 1312 

(Fed. Cir. 2009). Each prong of the function-way-result 

test is a factual determination. In this case, neither party 

objects to employing the function-way-result test as a 

means to determine equivalency of these chemical compounds. 

Glenmark’s argument on appeal is limited to the district court’s determination that Glenmark’s isopropyl 

myristate performed substantially the same function as 

the claimed triglyceride and lecithin. We review the 

district court’s determination that they perform substantially the same function, a question of fact, for clear error. 

Biovail Corp. Int’l v. Andrx Pharm., Inc., 239 F.3d 1297, 

1300 (Fed. Cir. 2001). To be clear, we are not presented 

with the issue of the substantiality of the differences 

between the chemical structures of isopropyl myristate, 

triglyceride, and lecithin. This appeal is limited to 

whether the district court clearly erred when it determined that triglyceride and lecithin function as penetration enhancers in the claimed compounds.

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INTENDIS GMBH v. GLENMARK PHARMACEUTICALS INC. 7

Glenmark’s non-infringement argument was based on 

the claim elements triglyceride and lecithin (collectively, 

“claimed excipients”), which are recited in the sole independent claim 1. Even though Glenmark’s generic product did not physically contain triglyceride or lecithin, the 

district court found that the claimed excipients were met 

under the doctrine of equivalents. First, the court found 

that isopropyl myristate in Glenmark’s generic product 

(“Glenmark’s excipient”) performs substantially the same 

function as the claimed excipients—namely, enhancing 

azelaic acid’s penetration of the skin. It reasoned that 

several experts testified that the claimed excipients could 

act as penetration enhancers and that “nothing in the 

record” indicated they could not. It also reasoned that 

Glenmark’s ANDA included repeated statements that 

both Glenmark’s excipient and the claimed excipients 

function as penetration enhancers. It noted that Glenmark “should not be permitted to liken their product to 

the claimed composition to support their bid for FDA 

approval, yet avoid the consequences of such a comparison 

for purposes of infringement.” Intendis, 117 F. Supp. 3d 

at 573. Second, the court found that Glenmark’s excipient 

performed in substantially the same way as the claimed 

excipients—namely, by disrupting the lipids in the skin’s 

outermost layer, known as the stratum corneum. It based 

its finding on testimony by various experts, as supported 

by scientific literature. Third, the court found that Glenmark’s excipient obtained substantially the same result 

as the claimed excipients—namely, a therapeutically 

effective azelaic acid composition that is able to penetrate 

the skin in order to deliver the active ingredient. It relied 

on data from the ’070 patent, Glenmark’s own patent 

application, a skin penetration study, and a clinical trial.

On appeal, Glenmark argues that the district court 

erred in its finding regarding the function prong because 

Appellees failed to prove that the claimed excipients 

function as penetration enhancers in the claimed composiCase: 15-1902 Document: 56-2 Page: 7 Filed: 05/16/2016
8 INTENDIS GMBH v. GLENMARK PHARMACEUTICALS INC. 

tion. It argues that “[t]he ’070 patent itself is silent on 

the question of whether lecithins or triglycerides function 

as penetration enhancers.” Intendis, 117 F. Supp. 3d at 

572. According to Glenmark, this absence of support in 

the patent itself for the notion that the claimed excipients 

function as penetration enhancers is fatal to Appellees’ 

infringement case. Glenmark argues that Appellees’ 

theory is also contradicted by evidence outside the patent. 

It points to Appellees’ FDA filings and development 

reports as such examples, which identified the claimed 

lecithin and triglyceride as an emulsifier and an emollient, respectively. It argues that not a single literature 

reference in evidence identified lecithin or triglyceride as 

a penetration enhancer, and Appellees’ expert testimony 

was rejected by the district court. According to Glenmark, 

the district court justified its finding that the claimed 

excipients function as penetration enhancers on the basis 

that the evidence did not exclude that possibility, despite 

the lack of any affirmative evidence.

We see no clear error in the district court’s finding of 

infringement under the doctrine of equivalents. As an 

initial matter, we disagree that the lack of disclosure of 

the claimed excipients as penetration enhancers in the 

’070 patent is fatal to Appellees’ infringement case. We 

have never held that a patent must spell out a claim 

element’s function, way, and result in order for the doctrine of equivalents to apply as to that element. To the 

contrary, we have held that “[w]hen the claims and specification of a patent are silent as to the result of a claim 

limitation, . . . we should turn to the ordinary skilled 

artisan.” Stumbo v. Eastman Outdoors, Inc., 508 F.3d 

1358, 1365 (Fed. Cir. 2007). 

Certainly, a patent’s disclosure is relevant and can at 

times be dispositive of the function. Glenmark is correct 

that the proper analysis focuses on the claimed element’s 

function in the claimed composition, not a function that 

element could perform in the abstract divorced from the 

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INTENDIS GMBH v. GLENMARK PHARMACEUTICALS INC. 9

claimed composition. But Glenmark is wrong to the 

extent that it argues that a determination of the claimed 

element’s function is limited to a review of the intrinsic 

record. The relevant inquiry is what the claim element’s 

function in the claimed composition is to one of skill in the 

art, and a fact finder may rely on extrinsic evidence in 

making this factual determination. Zenith Labs., Inc. v. 

Bristol-Myers Squibb Co., 19 F.3d 1418, 1425 (Fed. Cir. 

1994). 

Glenmark argues that the district court erred in its 

determination that the claimed excipients function as 

penetration enhancers in light of the evidence of record. 

We see no clear error in this district court fact finding. 

Fatal to Glenmark’s argument is its own ANDA submission to the FDA repeatedly referring to the claimed excipients (triglyceride and lecithin) as penetration enhancers. 

For example, Glenmark stated in its filing to the FDA 

that “[i]sopropyl myristate was selected as [a] penetration 

enhancer instead of lecithin and medium chain triglyceride” under the heading “Selection of penetration enhancer.” J.A. 5865. Glenmark’s repeated statements to the 

FDA that the claimed excipients function as penetration 

enhancers tend to show that one of skill in the art would 

understand the claimed excipients to function as penetration enhancers. We see no reason why a district court 

acting as a fact finder should ignore a party’s representation to a federal regulatory body that is directly on point. 

Based on this record, the district court’s finding regarding 

the function of the claimed excipients is not clearly erroneous. 

In a strange turn of events, Glenmark argued at oral 

argument to this court that its statements in its FDA 

submissions about the claimed excipients (triglyceride 

and lecithin) functioning as penetration enhancers should 

be rejected and cannot be evidence to support the district 

court’s finding. It argued that “lecithin and triglycerides 

are not known to the art as penetration enhancers” and 

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10 INTENDIS GMBH v. GLENMARK PHARMACEUTICALS INC. 

that its representation to the FDA that they do function 

as penetration enhancers was a “guess” and “wrong.” 

Oral Argument at 10:49–13:38, Intendis GmbH v. Glenmark Pharm. Inc., No. 2015-1902 (Fed. Cir. Jan. 8, 2016), 

available at http://oralarguments.cafc.uscourts.gov/

default.aspx?fl=2015-1902.mp3. These seemingly extemporaneous arguments do not persuade us that there is 

clear error in the district court’s decision that isopropyl 

myristate in Glenmark’s generic product and the claimed 

triglyceride and lecithin perform substantially the same 

function. No such arguments were made by Glenmark in 

any of its briefing to this court. And when asked whether 

Glenmark had notified the FDA of these purported inaccurate representations to the FDA, Glenmark’s counsel 

was unaware of such notification. Id. at 11:53–12:25. 

The district court did not clearly err in its findings regarding the doctrine of equivalents. 

II. Encompassing the Prior Art

A patentee may not assert “a scope of equivalency 

that would encompass, or ensnare, the prior art.” DePuy 

Spine, Inc. v. Medtronic Sofamor Danek, Inc., 567 F.3d 

1314, 1322 (Fed. Cir. 2009) (quotation marks omitted). 

Even if an accused element meets the function-way-result 

test, no equivalent will be found if the scope of equivalency would capture the prior art. Hypothetical claim analysis is a practical method to determine whether an 

equivalent would impermissibly ensnare the prior art. 

See Ultra-Tex Surfaces, Inc. v. Hill Bros. Chem. Co., 204 

F.3d 1360, 1364 (Fed. Cir. 2000). Hypothetical claim 

analysis is a two-step process. The first step is “to construct a hypothetical claim that literally covers the accused device.” DePuy Spine, 567 F.3d at 1324. Next, 

prior art introduced by the accused infringer is assessed 

to “determine whether the patentee has carried its burden 

of persuading the court that the hypothetical claim is 

patentable over the prior art.” Id. at 1325. In short, we 

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INTENDIS GMBH v. GLENMARK PHARMACEUTICALS INC. 11

ask if a hypothetical claim can be crafted, which contains 

both the literal claim scope and the accused device, without ensnaring the prior art. We review a district court’s 

conclusion that a hypothetical claim does not encompass 

the prior art de novo and resolution of underlying factual 

issues for clear error. Id. at 1324. 

The district court determined that a proper hypothetical claim included the claimed excipients and Glenmark’s 

excipient, namely, the hypothetical claim includes isopropyl myristate as an alternative to the claimed triglyceride 

and lecithin. Glenmark argued that finding infringement 

under the doctrine of equivalents would ensnare a prior 

art reference entitled “In vitro permeation of azelaic acid 

from viscosized microemulsions” (“Gasco”), which disclosed a microemulsion containing azelaic acid as the 

active ingredient and DMSO as a penetration enhancer. 

The parties agreed that Gasco did not disclose isopropyl 

myristate, lecithin, or triglyceride. The district court 

determined that the hypothetical claim was not anticipated or rendered obvious by Gasco, and rejected Glenmark’s 

argument that finding infringement under the doctrine of 

equivalents would ensnare Gasco. It reasoned, based on 

expert testimony, that a skilled artisan (i) would not 

necessarily have substituted the hypothetical claim

excipient (isopropyl myristate or lecithin and triglyceride) 

for Gasco’s DMSO, and (ii) would not have had a reasonable expectation of success in doing so.

Glenmark argues that the district court erred in determining that the doctrine of equivalents was not precluded by ensnarement. It argues that the district court’s 

hypothetical claim was “inexplicably narrower” than 

Appellees’ range of equivalents. It argues that a proper 

hypothetical claim should have matched Appellees’ theory 

of infringement and thus included any penetration enhancer. It argues that a proper hypothetical claim would 

have been anticipated by or obvious over the prior art and 

thus the doctrine of equivalents should be precluded.

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12 INTENDIS GMBH v. GLENMARK PHARMACEUTICALS INC. 

We agree with the district court’s determination that 

its infringement finding under the doctrine of equivalents 

did not impermissibly read on the prior art. Hypothetical 

claims extend the actual claim to literally recite the 

accused product. The district court adopted a proper 

hypothetical claim, one that includes triglycerides and 

lecithin or alternatively isopropyl myristate. It correctly 

rejected as too broad Glenmark’s proposed hypothetical 

claim which would cover all penetration enhancers. The 

district court’s infringement finding was that the excipient in Glenmark’s product (isopropyl myristate) was 

equivalent to the claimed excipients (lecithin and triglycerides); it was not a finding that any penetration enhancer would be equivalent to the claimed excipients. See 

Graver Tank & Mfg. Co. v. Linde Air Prods. Co., 339 U.S. 

605, 609 (1950) (“What constitutes equivalency must be 

determined against the context of the patent, the prior art, 

and the particular circumstances of the case. . . . In determining equivalents, things equal to the same thing 

may not be equal to each other and, by the same token, 

things for most purposes different may sometimes be 

equivalents.”). The district court properly rejected Glenmark’s argument that the hypothetical claim must be 

constructed to capture all penetration enhancers. Glenmark does not challenge the district court’s determination 

that the hypothetical claim as constructed would have 

been patentable. Thus, we see no reversible error in the 

district court’s conclusion that Gasco does not bar the 

application of the doctrine of equivalents to find Glenmark’s generic version to infringe the asserted claims.

III. Prosecution History Estoppel

We have summarized the doctrine of prosecution history estoppel as follows:

[P]rosecution history estoppel limits the broad application of the doctrine of equivalents by barring 

an equivalents argument for subject matter relinCase: 15-1902 Document: 56-2 Page: 12 Filed: 05/16/2016
INTENDIS GMBH v. GLENMARK PHARMACEUTICALS INC. 13

quished when a patent claim is narrowed during 

prosecution. We have recognized that prosecution 

history estoppel can occur during prosecution in 

one of two ways, either (1) by making a narrowing 

amendment to the claim (“amendment-based estoppel”) or (2) by surrendering claim scope 

through argument to the patent examiner (“argument-based estoppel”).

Conoco, Inc. v. Energy & Envtl. Int’l, L.C., 460 F.3d 1349, 

1363 (Fed. Cir. 2006) (citations omitted). With respect to 

the amendment-based estoppel, the Supreme Court has 

explained:

A patentee’s decision to narrow his claims through 

amendment may be presumed to be a general disclaimer of the territory between the original claim 

and the amended claim. There are some cases, 

however, where the amendment cannot reasonably be viewed as surrendering a particular equivalent. The equivalent may have been 

unforeseeable at the time of the application; the 

rationale underlying the amendment may bear no 

more than a tangential relation to the equivalent 

in question; or there may be some other reason 

suggesting that the patentee could not reasonably 

be expected to have described the insubstantial 

substitute in question. In those cases the patentee can overcome the presumption that prosecution 

history estoppel bars a finding of equivalence.

Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., 

Ltd., 535 U.S. 722, 740–41 (2002). We review de novo 

issues relating to the application of prosecution history 

estoppel. Schwarz Pharma, Inc. v. Paddock Labs., Inc., 

504 F.3d 1371, 1375 (Fed. Cir. 2007).

The district court rejected Glenmark’s argument that 

the ’070 patent applicants surrendered a lecithin-free 

composition (e.g., Glenmark’s proposed generic product) 

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14 INTENDIS GMBH v. GLENMARK PHARMACEUTICALS INC. 

as an equivalent during prosecution. During prosecution, 

the examiner noted that two dependent claims, which 

recited a lecithin “concentration of up to 1%” and “concentration of up to 3%,” respectively, could include zero 

lecithin. Applicants responded that those range limitations clearly did not include zero because they “are only in 

claims dependent on independent claims, which clearly 

require [lecithin].” J.A. 4386–87 (noting that the examiner’s argument “is not well taken.”). Regardless, applicants amended the two dependent claims to recite a 

lecithin “concentration of from more than 0 to 1%” and 

“concentration of from more than 0 to 3%,” respectively, 

noting that they were “amended to expressly state what 

has already been made clear on the record.” The district 

court determined that “taken in context,” the amendments were for clarification purposes, “not to disclaim 

formulations with zero lecithin.” It noted that Glenmark 

did not dispute that independent claim 1 always required 

lecithin, and consequently, both dependent claims also 

always required lecithin.

Glenmark argues that the district court erred in determining that prosecution history estoppel did not apply 

to bar the doctrine of equivalents. It argues that applicants expressly disavowed and disclaimed formulations 

without lecithin.

We see no error in the district court’s analysis. The 

district court correctly determined that prosecution history estoppel did not preclude the capture of Glenmark’s 

lecithin-free composition as an equivalent. Argumentbased estoppel only applies when the prosecution history 

“evince[s] a clear and unmistakable surrender of subject 

matter.” Deering Precision Instruments, LLC v. Vector 

Distrib. Sys., Inc., 347 F.3d 1314, 1326 (Fed. Cir. 2003) 

(citation and punctuation omitted). Applicants’ clarifying 

statement, “Since the dependent claims must limit the 

independent claims, the meaning is clear that zero 

amounts are not included,” J.A. 4387, did not clearly and 

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INTENDIS GMBH v. GLENMARK PHARMACEUTICALS INC. 15

unmistakably disavow claim scope to distinguish prior 

art. Amendment-based estoppel does not apply because 

the amendment was not a narrowing amendment made to 

obtain the patent. Rather, this record demonstrates that 

the amendment to the dependent claims was a clarifying 

amendment. As dependent claims can never be broader 

than the independent claim from which they depend, the 

dependent claims as originally written could not have 

included 0% lecithin. The amendment was, as the comments themselves make clear, a clarifying amendment 

and it does not give rise to prosecution history estoppel. 

We see no error in the district court’s determination that 

prosecution history estoppel does not apply. 

IV. Obviousness

The district court determined that the asserted claims 

would not have been obvious over the previouslymarketed Skinoren® cream in combination with 

(i) references disclosing formulations containing the 

claimed excipients (“non-azelaic acid art”), and 

(ii) references disclosing formulations containing azelaic 

acid (“azelaic acid art”).4 Skinoren® cream contained 20% 

azelaic acid and was marketed for skin conditions. The 

district court found that Skinoren®’s formulation had 

certain undesirable qualities, and that a skilled artisan 

would consider developing an alternative to Skinoren® in 

a different dosage form given the market forces and the 

deficiencies of Skinoren®. It also found that a skilled 

artisan would have been motivated to pursue a hydrogel 

formulation of azelaic acid based on Maru, one of the 

pieces of azelaic acid art, which the district court found to 

 

4 The non-azelaic acid art was PCT Application 

Pub. Nos. WO 93/18752 and WO 95/05163. The azelaic 

acid art was articles by Maru, Gasco, and Pattarino; U.S. 

Patent No. 5,385,943; and PCT Application Pub. 

No. WO 93/39119.

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16 INTENDIS GMBH v. GLENMARK PHARMACEUTICALS INC. 

disclose a hydrogel formulation containing azelaic acid. It 

found, however, that the record did not show that the 

artisan would have been motivated to use the claimed 

excipients (triglyceride and lecithin). It noted that Glenmark’s only support to combine Maru with either of the 

two references that disclose the claimed excipients was 

the testimony by Glenmark’s expert that a skilled artisan 

“could have put . . . information together from another two 

publications” to render claim 1 obvious. It reasoned that 

this cursory statement was insufficient to meet Glenmark’s burden of showing by clear and convincing evidence a motivation to combine Maru with other prior art 

to render the claims obvious. It also found that even if 

Glenmark had presented evidence to show motivation to 

combine, Glenmark failed to carry its burden to demonstrate a reasonable expectation of success in making the 

combination. It found—based on fact and expert testimony—that “swapping ingredients in complex chemical 

formulations is anything but ‘routine.’” J.A. 65. It wrote 

that Glenmark did not present testimony or other evidence regarding an expectation of success. It also determined that the objective indicia of unexpected results and 

commercial success supported its conclusion of nonobviousness.

Glenmark argues that the district court erred in concluding that the asserted claims would not have been 

obvious. It argues that a skilled artisan would have 

known how to “successfully” combine the non-azelaic acid 

art with the azelaic acid art. It argues that the objective 

indicia do not overcome its “strong” prima facie case of 

obviousness. According to Glenmark, the district court 

erred in finding that the claimed compositions demonstrated unexpected results. It also argues Appellees’ 

“equivocal” evidence concerning commercial success does 

not support the district court’s nonobviousness conclusion.

The district court correctly concluded that the asserted claims would not have been obvious. We discern no 

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INTENDIS GMBH v. GLENMARK PHARMACEUTICALS INC. 17

clear error in the district court’s finding that a skilled 

artisan would not have been motivated to combine the 

prior art or in finding no reasonable expectation of success

based on the evidence of record. Moreover, we see no 

clear error in the district court’s findings with respect to 

objective indicia of nonobviousness. 

CONCLUSION

The district court did a commendable job in rendering 

its detailed and thorough opinion. Because we see no 

reversible error in the district court’s decision that Glenmark’s generic product infringed the asserted claims and 

that the asserted claims are not invalid, the district 

court’s judgment is affirmed. 

AFFIRMED

COSTS

Costs to the Appellees. 

Case: 15-1902 Document: 56-2 Page: 17 Filed: 05/16/2016