Pfizer, Inc. v. Teva Pharmaceuticals USA, Inc.

United States Court of Appeals for the Federal Circuit
2007-1271

PFIZER, INC., PHARMACIA CORP., PHARMACIA & UPJOHN, INC.,
PHARMACIA & UPJOHN COMPANY, G.D. SEARLE & CO., G.D. SEARLE LLC,
SEARLE LLC (Delaware) and SEARLE LLC (Nevada),

Plaintiffs-Appellees,

v.

TEVA PHARMACEUTICALS USA, INC.,

Defendant-Appellant.

Leora Ben-Ami, Kaye Scholer LLP, of New York, New York, argued for plaintiffs-
appellees. With her on the brief were Daniel L. Reisner and Daniel Forchheimer. Of
counsel on the brief was David De Lorenzi, Gibbons P.C., of Newark, New Jersey.

Henry C. Dinger, P.C., Goodwin Procter LLP, of Boston, Massachusetts, argued
for defendant-appellant. With him on the brief were Thomas L. Creel, P.C., Keith A.
Zullow, Christopher M. Ries, of New York, New York.

Appealed from: United States District Court for the District of New Jersey

Judge John C. Lifland
 United States Court of Appeals for the Federal Circuit

2007-1271

PFIZER, INC., PHARMACIA CORP., PHARMACIA & UPJOHN, INC.,
PHARMACIA & UPJOHN COMPANY, G.D. SEARLE & CO., G.D. SEARLE LLC,
SEARLE LLC (Delaware) AND SEARLE LLC (Nevada),

Plaintiffs-Appellees,

v.

TEVA PHARMACEUTICALS USA, INC.,

Defendant-Appellant.

Appeal from the United States District Court for the District of New Jersey in case no.
04-754, Judge John C. Lifland.

___________________________

DECIDED: March 7, 2008
___________________________

Before MICHEL, Chief Judge, DYK, Circuit Judge, and KENNELLY, District Judge. *

DYK, Circuit Judge.

Appellant Teva Pharmaceuticals USA, Inc. (“Teva”) appeals from a final

judgment of the United States District Court for the District of New Jersey, entered after

a bench trial, in favor of Appellees Pfizer, Inc. et al. (collectively “Pfizer”). Pfizer Inc. v.

Teva Pharms. USA, Inc., 482 F. Supp. 2d 390 (D.N.J. 2007). The district court held that

Teva infringed three patents owned by Pfizer: specifically, claims 1-3, 7-9, 11, and 13

of U.S. Patent No. 5,466,823 (“the ’823 patent”), claims 1-5 and 15-18 of U.S. Patent

*
Honorable Matthew F. Kennelly, District Judge, United States District Court for
the Northern District of Illinois, sitting by designation.
No. 5,563,165 (“the ’165 patent”), and claims 1-4 and 11-17 of U.S. Patent No.

5,760,068 (“the ’068 patent”). The district court also held that the asserted claims of the

three patents were not invalid for a best mode violation and that the asserted claims of

the ’068 patent were not invalid for obviousness-type double patenting. The district

court held that none of the patents was unenforceable on grounds of inequitable

conduct. We find that the asserted ’068 patent claims are invalid based on double

patenting. However, we agree that claim 9 of the ’823 patent and claim 17 of the ’165

patent are not invalid for a best mode violation. The ’823, ’165 and ’068 patents also

are not unenforceable for inequitable conduct. We therefore affirm-in-part and reverse-

in-part.

BACKGROUND

Pfizer produces and sells the drug Celebrex, a non-steroidal anti-inflammatory

drug (“NSAID”), for the treatment of osteoarthritis and rheumatoid arthritis. Pfizer owns

the patents-in-suit, which encompass a broad genus of non-steroidal anti-inflammatory

compounds, compositions using those compounds, and methods of using those

compositions. The claims of the patents include celecoxib—the active ingredient in

Celebrex.

Teva is a generic drug manufacturer. Pursuant to the provisions of the Hatch-

Waxman Act, 21 U.S.C. § 355, Teva filed an Abbreviated New Drug Application

(“ANDA”) with the Food and Drug Administration (“FDA”) addressed to a proposed drug

identified as “Celecoxib Capsules, 100 mg, 200 mg, and 400 mg.” Pfizer, 482 F. Supp.

2d at 398. Because the patents covering celecoxib are listed in the Orange Book, Teva

was required to certify that those patents “[are] invalid or will not be infringed by the

2007-1271 2
manufacture, use or sale of the new drug for which the [ANDA] is submitted.” 21 U.S.C.

§ 355(j)(2)(A)(vii)(IV). 1 Teva’s ANDA contained the required “Paragraph IV

certification.” That certification did not dispute that the filing of Teva’s ANDA would

infringe the patents, but challenged the validity of the patents covering celecoxib. In

February 2004, in response to the submission of Teva’s ANDA, Pfizer initiated this

litigation by filing a patent infringement action against Teva pursuant to 35 U.S.C.

§ 271(e). Pfizer alleged that Teva’s ANDA filing was an act of patent infringement

because the ANDA sought approval to manufacture, use or sell a drug claimed in a

patent or the use of which is claimed in a patent. In May 2004, Teva filed an answer. It

did not argue that its ANDA was not within the scope of the claims but rather asserted

affirmative defenses that the patents-in-suit were invalid or unenforceable. Teva did not

counterclaim. Understanding these affirmative defenses requires an understanding of

the history of NSAIDs and the prosecution history of the three patents.

Traditional NSAIDs have been used for many years to treat people suffering

from pain and other symptoms associated with inflammation. Aspirin, for example, has

been on the market for nearly a century. Aspirin was followed several decades later by

the introduction of other similar drugs, such as ibuprofen and naproxen. Although these

traditional NSAIDs were effective in treating pain from inflammation, they were also

associated with harmful gastrointestinal side effects, ranging from slight stomach

discomfort to serious life-threatening ulcers.

1
The Hatch-Waxman process is described in detail in prior decisions. See,
e.g., Andrx Pharms., Inc. v. Biovail Corp., 276 F.3d 1368, 1370-71 (Fed. Cir. 2002).

2007-1271 3
 In the early 1970s, scientists made a breakthrough in understanding the

operative mechanism of the traditional NSAIDs when they discovered that the drugs

inhibited the cyclooxygenase (“COX”) enzyme in the body, which produces small

molecules associated both with pain and inflammation and also with good housekeeping

functions that contribute to, for example, good gastrointestinal physiology. Several

years later, scientists made another significant breakthrough when they discovered that

there were in fact at least two different kinds of COX enzymes: the first, COX-1,

produces the molecules associated with the good housekeeping functions inside the

body, and the second, COX-2, produces the molecules associated with pain and

inflammation. Traditional NSAIDs were found to inhibit both of these COX enzymes. In

the years following and leading up to the discovery of celecoxib, scientists began

searching for a compound that would selectively inhibit the COX-2 enzyme to treat pain

and inflammation without inhibiting the COX-1 enzyme. In other words, they began to

focus their efforts on identifying a compound that would effectively treat pain without the

harmful side effects identified with the traditional NSAIDs. See generally Univ. of

Rochester v. G.D. Searle & Co., 358 F.3d 916, 917-18 (Fed. Cir. 2004) (describing the

development of modern NSAIDs).

By 1993, Pfizer had identified several new compounds that it believed would

selectively inhibit COX-2. On November 30, 1993, Pfizer filed U.S. Patent Application

No. 08/160,594 (“the ’594 application”) with the Patent and Trademark Office (“PTO”)

that claimed a broad range of these chemical compounds. The application included

claims directed to the chemical compounds themselves, to compositions using these

2007-1271 4
compounds, and to methods of using these compounds, including specific claims to

celecoxib.

In an office action dated July 12, 1994, the patent examiner issued a restriction

requirement, which identified the compound claims, the composition claims, and the

method claims as each directed to patentably distinct subject matter. The restriction

requirement required Pfizer to select for prosecution one of these three claim groups. In

the same office action, the examiner further required the applicant “to elect a single

disclosed species” that the examiner identified. 2 J.A. at 26326. In response, Pfizer

elected to prosecute the generic compound claims and, within that genus, the single

2
The examiner’s restriction requirement provided:

No generic claim being allowable, the following action is also taken.
Restriction to one of the following inventions is required under
35 U.S.C. [§] 121:

I. Claims 1-20, compounds.
II. Claims 21-26, compositions.
III. Claims 27-37, methods of use.

The above groups are identified as general areas. Accordingly, as
groups they are independent or distinct as the compounds of Group I
would differ in scope from the compositions of Group II, the products
would be capable of more than one use and separate search
considerations are involved.
The above groups themselves are inclusive of patentably distinct
subject matter. Accordingly, along with the election of one of the above
groups the following action is also taken.
Claims 1, 16, 21 and 27 are generic to a plurality of disclosed
patentably distinct species comprising for example: the compounds of (1)
Example 1, (2) Example 3, (4) [sic] Example 4, (5) Example 16, etc., the
method of treating fever using (5) the compound of Example 1, etc.
Applicant is required under 35 U.S.C. § 121 to elect a single disclosed
species, even though this requirement is traversed.

J.A. at 26325-26.

2007-1271 5
compound species celecoxib. The resulting compound claims remaining in the original

’594 application were ultimately allowed, and the application issued as the ’823 patent.

Subsequent to the restriction requirement but before the ’594 application issued,

Pfizer filed a series of continuation applications claiming priority to the ’594 application

and covering the non-elected subject matter which it had elected not to prosecute in the

original ’594 application. 3 In particular, Pfizer filed a divisional application, which

ultimately issued as the ’165 patent, that included the restricted-out composition claims,

and a continuation-in-part application (“CIP”), which ultimately issued as the ’068 patent,

that included the restricted-out method claims.

Following an 18-day bench trial, the district court rejected each of Teva’s

invalidity arguments and found Pfizer’s patents infringed. The district court first rejected

Teva’s defense that the asserted patents were invalid as obvious over the prior art.

Teva does not appeal that aspect of the district court’s decision, and we do not discuss

it here. The district court rejected Teva’s best mode defense as to all of the asserted

patents because it held that Pfizer’s subjective preference for COX-2 selectivity was not

the type of preference that best mode requires an applicant to disclose. The district

court also rejected Teva’s double patenting argument based on the theory that the ’165

patent was prior art to the ’068 patent. The district court held that, under 35 U.S.C.

§ 121, the ’165 patent could not be used as prior art against the ’068 patent. Finally, the

district court held that there was no inequitable conduct. Teva asserted that two Merck

references, International Application No. WO 95/00501 (“the ’501 application”) and U.S.

3
Several of these applications were directed to the several non-elected
species of compounds. Those applications ultimately issued as patents, but since they
do not cover celecoxib, they are not at issue here.

2007-1271 6
Patent No. 5,474,995 (“the ’995 patent”) should have been disclosed to the PTO. The

district court held that they were not material because they did not qualify as prior art

under 35 U.S.C. § 102(e). The latter holdings are the subject of this appeal.

After trial, the district court issued a judgment, concluding that Teva infringed

each of the ’823, ’165, and ’068 patents and ordering that Teva’s ANDA not be

approved earlier than the expiration date of the ’823, ’165, and ’068 patents. The

judgment also included an order enjoining Teva from engaging in the manufacture, use,

offer to sell, sale, or importation into the United States of any product comprising the

chemical compound celecoxib. Teva timely appealed. We have jurisdiction pursuant to

28 U.S.C. § 1295(a)(1).

DISCUSSION

I

We first consider whether the claims of the ’068 method patent are invalid based

on obviousness-type double patenting over the ’165 composition patent. If the ’068

patent is invalid, Pfizer is not entitled to an injunction beyond the expiration date of the

’165 patent. The district court held that the safe-harbor provision of 35 U.S.C. § 121

prevented the ’165 patent from serving as prior art with respect to the ’068 patent. This

was so because both the ’165 patent and the ’068 patent derived from applications filed

in response to the restriction requirement made in the common parent application.

Because it found that the ’165 patent was not prior art, the district court held that the

’068 patent was not invalid on grounds of double patenting.

2007-1271 7
 A

The third sentence of section 121 provides a safe harbor to patents that issue on

applications filed as a result of a restriction requirement:

A patent issuing on an application with respect to which a requirement for
restriction under this section has been made, or on an application filed as
a result of such a requirement, shall not be used as a reference either in
the Patent and Trademark Office or in the courts against a divisional
application or against the original application or any patent issued on
either of them, if the divisional application is filed before the issuance of
the patent on the other application.

35 U.S.C. § 121 (2000). In addition to the express requirements of section 121, we

have also construed the statute to require consonance: the applicant must maintain the

line of demarcation between the independent and distinct inventions that prompted the

restriction requirement. Gerber Garment Tech. v. Lectra Sys., Inc., 916 F.2d 683, 688

(Fed. Cir. 1990). This consonance requirement prevents an applicant from amending

the claims in the divisional application in a way that would violate the originally imposed

restriction requirement and thereby impermissibly extend the patent term as to that

subject matter. Id. 4

4
Teva argues that the ’165 patent was not consonant with an election of
species restriction requirement made in the parent application. The district court
disagreed, finding that the election of species was not a restriction requirement under
section 121, and that the ’165 patent maintained consonance with the
compound/composition/method restriction requirement. We do not reach these issues
because we find that section 121 is inapplicable.

2007-1271 8
 Teva contends that section 121 applies exclusively to divisional applications, and

that because the ’068 patent issued on a CIP rather than on a divisional application, it

does not fall within the terms of the statute. 5

Although both are types of continuing applications, divisionals and CIPs differ

significantly in at least one respect: a divisional application contains an identical

disclosure to its parent application, but a CIP introduces new matter. A CIP is “just what

its name implies. It partly continues subject matter disclosed in a prior application, but it

adds new subject matter not disclosed in the prior application.” Univ. of W. Va. Bd. of

Trs. v. Vanvoorhies, 278 F.3d 1288, 1297 (Fed. Cir. 2002); see also Manual of Patent

Examining Procedure (“MPEP”) § 201.08 (8th ed., Rev. 5, 2006) (“A continuation-in-part

is an application filed during the lifetime of an earlier nonprovisional application,

repeating some substantial portion or all of the earlier nonprovisional application and

adding matter not disclosed in the said earlier nonprovisional application.”) (emphasis in

original). A divisional application is defined as “[a] later application for an independent

or distinct invention, carved out of a pending application and disclosing and claiming

only subject matter disclosed in the earlier or parent application . . . .” MPEP § 201.06.

5
The district court declined to consider this issue below on the ground that
it had been raised too late in the proceedings. We need not address the propriety of the
district court’s refusal to consider this issue because we may properly decide the issue,
even if not raised below, since the issue of whether section 121 applies to CIPs is a
predicate legal issue necessary to a resolution of the issues before the court. See
Kamen v. Kemper Fin. Servs., Inc., 500 U.S. 90, 99 (1991); Forshey v. Principi, 284
F.3d 1335, 1356 (Fed. Cir. 2002) (en banc) superseded by statute on other grounds, as
recognized in Morgan v. Principi, 327 F.3d 1357 (Fed. Cir. 2003).
Also, we see no basis for the claim that Pfizer was somehow prejudiced by
Teva’s failure to raise this purely legal issue earlier in the proceeding. We also
conclude that Teva adequately raised the issue on appeal in its “Statement of Issues.”

2007-1271 9
A divisional application “is often filed as a result of a restriction requirement made by the

examiner.” Id.

Pfizer argues that the terms “divisional” and “continuation-in-part” are merely

labels used for administrative convenience, and that accordingly, although the ’068 is

termed a CIP, it is in effect a divisional for purposes of section 121. In other words,

Pfizer contends that the term “divisional application” as it is used in section 121 refers

broadly to any type of continuing application filed as a result of a restriction, regardless

of whether it is labeled by the PTO, for administrative purposes, as a divisional, a

continuation, or a CIP. We disagree.

Section 121 explicitly refers to “divisional applications.” That section provides:

If two or more independent and distinct inventions are claimed in one
application, the Director may require the application to be restricted to one
of the inventions. If the other invention is made the subject of a divisional
application which complies with the requirements of section 120 of this title
it shall be entitled to the benefit of the filing date of the original application.
A patent issuing on an application with respect to which a requirement for
restriction under this section has been made, or on an application filed as
a result of such a requirement, shall not be used as a reference either in
the Patent and Trademark Office or in the courts against a divisional
application or against the original application or any patent issued on
either of them, if the divisional application is filed before the issuance of
the patent on the other application. If a divisional application is directed
solely to subject matter described and claimed in the original application
as filed, the Director may dispense with signing and execution by the
inventor. The validity of a patent shall not be questioned for failure of the
Director to require the application to be restricted to one invention.

35 U.S.C. § 121 (emphases added). As noted above, the third sentence of the statute

provides a safe harbor (for patents or applications derived as the result of a restriction

requirement) from attack based on the original application (or a patent issued

therefrom), or based on applications or patents similarly derived from the same

2007-1271 10
restriction requirement. That safe harbor, by its literal terms, protects only “divisional

application[s]” (or the original application) and patents issued on such applications.

The legislative history of section 121, like section 121 itself, refers specifically to

“divisional application[s].” The House Report, referring to section 121, states:

This section enacts as law existing practice with respect to division, at the
same time introducing a number of changes. Division is made
discretionary with the Commissioner. The requirements of section 120 are
made applicable and neither of the resulting patents can be held invalid
over the other merely because of their being divided in several patents. In
some cases a divisional application may be filed by the assignee.

H.R. Rep. No. 82-1923, at 20 (1952) (emphasis added).

The “changes” referred to in the legislative history included the safe-harbor

provision of section 121. Prior to the 1952 Patent Act, no protection was afforded to

patent applications filed as a result of a restriction requirement—referred to at the time

as a “requirement for division”—and such applications were often rejected or held

invalid on double patenting grounds. See Studiengesellschaft Kohle mbH v. N.

Petrochemical Co., 784 F.2d 351, 358 (Fed. Cir. 1986) (“SGK”) (Newman, J.,

concurring); In re Eisler, 203 F.2d 726 (CCPA 1953). Thus, although a requirement for

division embodied a determination by the PTO that the patent application contained

more than one patentably distinct invention, such a determination did not protect the

divisional application from rejection on grounds of double patenting. In re Isherwood, 46

App. D.C. 507, 512 (D.C. Cir. 1917) (holding that an examiner is not estopped from

rejecting a divisional application because of an earlier requirement for division). The

PTO and the courts were therefore not precluded from rejecting an application filed as a

result of a requirement for division based on the very same application from which the

subsequent application was divided. See In re Kauffman, 152 F.2d 991, 993 (CCPA

2007-1271 11
1946). Pursuant to this practice, a patent applicant could appeal an examiner’s

requirement for division, United States ex rel. Steinmetz v. Allen, 192 U.S. 543 (1904),

and “his failure to litigate the question was at his peril.” Kauffman, 152 F.2d at 993.

The inequity of this practice was well known by 1952. See In re Ferenci, 83 F.2d

279, 282-83 (CCPA 1936) (“One anomalous result . . . is that after division has been

required and the applicant has complied therewith, the divided claims have been

rejected on the ground of double patenting, although it is obvious that division was

required upon the theory that the original application contained claims for more than one

independent invention.”). 6 The purpose of section 121 was to eliminate this inequity

and thereby allow applicants to reasonably rely on restriction requirements. See SGK,

784 F.2d at 358 (Newman, J., concurring). Given the protection of section 121,

applicants would no longer need to appeal a restriction requirement because they would

no longer be penalized for acquiescing in an improper restriction requirement. See id.

at 359. The enactment of section 121, therefore, brought clarity and fairness to the

interaction between restriction and double patenting.

There is no suggestion, however, in the legislative history of section 121 that the

safe-harbor provision was, or needed to be, directed at anything but divisional

applications. The commentary and materials published since section 121’s enactment

similarly contain no suggestion that section 121 was meant to cover any applications

other than divisionals. 7 Although the legislative history reveals no reason why

6
See also W. F. Hyer, Note: Divisional Practice and Double Patenting, 17
Geo. Wash. L. Rev. 537 (1949).
7
See P.J. Federico, Commentary on the New Patent Act, at 35 (1954)
(reprinted at 75 J. Pat. & Trademark Off. Soc. 161, 196 (1993)); John C. McIntyre, Jr.,

2007-1271 12
Congress drafted section 121 only to benefit divisional applications, there are certainly

plausible reasons why Congress would have concluded that section 121 should be

limited to divisional applications, and not include CIPs. The need for the protection only

existed when a divisional application was filed as a result of the restriction. If the

section had included CIPs, which by definition contain new matter, the section might be

read as providing the earlier priority date even as to the new matter, contrary to the

usual rule that new matter is not entitled to the priority date of the original application.

See Asseff v. Marzall, 189 F.2d 660, 661 (D.C. Cir. 1951). There was no possible

reason for protecting the new matter from double patenting rejections.

The difference between divisional applications and CIPs, moreover, was well

known at the time that Congress enacted the 1952 Patent Act. The Manual of Patent

Examining Procedure in use at the time included definitions of the different types of

applications. A divisional was defined as “[a] later application for a distinct or

independent invention, carved out of a pending application and disclosing and claiming

nothing not disclosed in the earlier or parent application . . . .” MPEP § 201.06 (1st ed.,

1949). And a CIP was defined as “an application filed during the lifetime of an earlier

application by the same applicant, repeating some substantial portion or all of the earlier

application and adding matter not disclosed in the said earlier case.” Id. § 201.08

(emphasis in original). Indeed, these earlier definitions are nearly identical to those in

the latest edition of the MPEP (quoted above). Despite this awareness, however, the

drafters of section 121 chose to refer specifically and only to divisional (and original)

The Effect of a Restriction Requirement in the Patent and Trademark Office on a
Subsequent Double Patenting Adjudication, 4 AIPLA Q.J. 301 (1976).

2007-1271 13
applications. If the drafters wanted to include CIPs within the protection afforded by

section 121, they could have easily done so.

Pfizer’s only claimed authority for including CIP applications within the scope of

section 121 are three cases where this court, although it did not consider the question,

may have assumed that section 121 applied to CIP applications filed in response to a

restriction requirement. See Geneva Pharms., Inc. v. GlaxoSmithKline PLC, 349 F.3d

1373, 1382 (Fed. Cir. 2003); Gerber, 916 F.2d at 689; SGK, 784 F.2d at 355. But in two

of these cases we held that section 121 was inapplicable on other grounds, and thus did

not need to, and did not in fact address the divisional question. Geneva, 349 F.3d at

1382 (finding that the patentee did not comply with the consonance requirement);

Gerber, 916 F.2d at 689 (same). In the third, we disposed of the double patenting

issue on the ground that the claims of the patents were patentably distinct. SGK, 784

F.2d at 355. Since the issue now before us was not decided by those cases, they are

not binding authority. See Rhone Poulenc Agro, S.A. v. DeKalb Genetics Corp., 284

F.3d 1323, 1334 (Fed. Cir. 2002).

We conclude that the protection afforded by section 121 to applications (or

patents issued therefrom) filed as a result of a restriction requirement is limited to

divisional applications. We note that this interpretation of section 121 is consistent with

the PTO’s understanding of section 121. See Ex parte Granados, No. 2002-2030, 2003

WL 25283825, *11 (B.P.A.I. Sept. 26, 2003) (not selected for publication) (“[T]he instant

case is a continuation-in-part, not a divisional . . . . It therefore does not fall within the

literal terms of [section 121].”); see also MPEP § 804.01 (similarly referring to

“divisional” applications). Here, the ’068 patent, though it derived from the application

2007-1271 14
that led to the ’823 patent, was filed as a CIP and not a divisional application. We hold

that section 121 does not apply to the ’068 patent and that the ’165 patent may be used

to invalidate the ’068 patent. Given our conclusion, we do not consider Teva’s

alternative argument that section 121 does not apply because the ’165 patent is not

consonant with the restriction requirement made in the parent application.

B

Because section 121 does not prohibit us from using the ’165 patent as a

reference against the ’068 patent, we must next determine whether the claims of the

’068 patent are patentably distinct from the claims of the ’165 patent.

Obviousness-type double patenting is a judicially created doctrine that “prohibit[s]

a party from obtaining an extension of the right to exclude through claims in a later

patent that are not patentably distinct from claims in a commonly owned earlier patent.”

Eli Lilly & Co. v. Barr Labs., Inc., 251 F.3d 955, 967 (Fed. Cir. 2001). We have

identified two steps in an obviousness-type double patenting analysis. First, “a court

construes the claim[s] in the earlier patent and the claim[s] in the later patent and

determines the differences.” Id. at 968. Second, it determines whether those

differences render the claims patentably distinct. Id. “A later patent claim is not

patentably distinct from an earlier patent claim if the later claim is obvious over, or

anticipated by, the earlier claim.” Id. We have also held that a “claim to a method of

using a composition is not patentably distinct from an earlier claim to the identical

composition in a patent disclosing the identical use.” Geneva, 349 F.3d at 1385-86.

Double patenting is a question of law, which we review without deference. Ga.-Pac.

Corp. v. U.S. Gypsum Co., 195 F.3d 1322, 1326 (Fed. Cir. 1999).

2007-1271 15
 Here, although the district court first held that section 121 precluded the use of

the ’165 patent against the ’068 patent, the district court also found that if section 121

did not prevent the ’165 patent from being prior art, it would hold that the relevant claims

of the two patents were not patentably distinct. We agree that the relevant claims of the

two patents are not patentably distinct. The claims at issue of the ‘068 patent merely

recite methods of administering a “therapeutically-effective amount” of the compositions

found in claim 5 of the ’165 patent. Moreover, the term “therapeutically-effective

amount” is found in claim 1 of the ’165 patent and was stipulated by the parties to mean

the same thing in both patents. 8 Thus, we agree with the district court that the ’068

patent merely claims a particular use described in the ’165 patent of the claimed

compositions of the ’165 patent. 9 The asserted claims of the ’068 are therefore not

patentably distinct over the claims of the ’165 patent.

8
To the extent that Pfizer contends that we may not rely on the teachings of
the specification or claims in the ’165 patent to reject the claims of the ’068 patent, we
disagree. See Geneva, 349 F.3d at 1386. There is nothing that prevents us from
looking to the specification to determine the proper scope of the claims. In Geneva, we
stated:

It would shock one’s sense of justice if an inventor could receive a patent
upon a composition of matter, setting out at length in the specification the
useful purposes of such composition, manufacture and sell it to the public,
and then prevent the public from making any beneficial use of such
product by securing patents upon each of the uses to which it may be
adapted.

Id. (internal citation omitted).
9
Pfizer argues that claims 15-17 must be considered separately because
these claims are directed to the particular disorders of arthritis, pain, and fever. We find
that these recitations do not claim non-obvious subject matter, since claim 5 of the ’165
patent generally claims compounds, which the specification indicates are used to treat
“inflammation-related disorders.”

2007-1271 16
 We conclude that: (1) Pfizer cannot claim the protection of section 121 with

respect to the ’068 patent because that patent did not issue on a divisional application,

and (2) the asserted claims of the ’068 patent are not patentably distinct from the claims

of the ’165 patent. Accordingly, the ’068 patent is invalid for obviousness-type double

patenting. 10

II

We next consider Teva’s contention that the ’823 compound and ’165

composition patents are invalid because they violate the best mode requirement. The

best mode requirement is contained in 35 U.S.C. § 112: “The specification shall . . . set

forth the best mode contemplated by the inventor of carrying out his invention.” The test

for compliance with best mode is comprised of two steps: first, whether, “at the time of

filing the application, the inventor possessed a best mode for practicing the invention;”

and second, whether the inventor’s disclosure was “adequate to enable one of ordinary

skill in the art to practice the best mode of the invention.” Bayer AG v. Schein Pharms.,

Inc., 301 F.3d 1306, 1320 (Fed. Cir. 2002). The first prong is subjective and focuses on

the inventor’s state of mind at the time the application is filed; the second prong is

“objective and depends upon the scope of the claimed invention and the level of skill in

the relevant art.” Id. The “invention” referred to in the best mode test is the invention as

defined by the claims. Id. Typically, the best mode issue concerns the applicant’s

failure to disclose a preferred embodiment, but not always. In Bayer, we explained that

10
The effect of our decision is to require amendment to the district court’s
judgment to change the effective date of the order preventing approval of Teva’s ANDA.
Also, our determination requires the elimination of the provisions of the district court’s
order enjoining Teva from the manufacture or use of celecoxib in violation of the ’068
patent.

2007-1271 17
the best mode requirement does not “demand disclosure of every preference an

inventor possesses as of the filing date.” Id. at 1314-15. We held that the best mode

requirement does demand disclosure of an inventor’s preferred embodiment of the

claimed invention. Id. at 1316. However, it is not limited to that. We have recognized

that best mode requires inventors “to disclose aspects of making or using the claimed

invention [when] the undisclosed matter materially affect[s] the properties of the claimed

invention.” Id. at 1319.

We first consider Teva’s best mode challenge to the generic claims of the

compound and composition patents: claims 1-3, 7-8, 11, and 13 of the ’823 patent, and

claims 1-5, 15-16, and 18 of the ’165 patent. Teva contends, with respect to those

claims, that Pfizer violated the best mode requirement by failing to disclose its

preference for COX-2 selectivity. Here, Teva’s argument is limited. Teva does not

claim that Pfizer had a subjective, undisclosed preference for a particular compound (a

preferred embodiment) at the time it filed the patent applications. Rather, Teva argues

that the generic claims of the ’823 and ’165 patents do not teach one of skill in the art

how to arrive at the preferred embodiment because they do not reveal Pfizer’s

preference for compounds that demonstrate COX-2 selectivity. Teva asserts that,

without the knowledge of the preference for COX-2 selectivity, one of ordinary skill in

the art would not be able to identify a preferred embodiment (compound or composition)

in the generic claims.

It is undisputed that, at the time of filing, Pfizer preferred compounds and

compositions that were COX-2 selective, and that this preference was not disclosed in

either the compound or the composition applications. Moreover, according to Teva,

2007-1271 18
many of the claimed compounds are not in fact COX-2 selective. Teva contends that,

by concealing its preference for COX-2 selectivity, Pfizer was able to keep for itself the

crux of the invention. That is, Pfizer effectively hid among the many disclosed

compounds and compositions in the generic claims the one or two compounds that

were truly valuable by not disclosing how to identify which compounds displayed COX-2

selective characteristics. Without knowing the properties of the compound that Pfizer

would later single out, Teva argues, Pfizer could effectively withhold from the public its

actual invention—a compound or composition that was COX-2 selective. This

preference, Teva argued, was relevant to using the claimed invention. The district court

held that, “[a]lthough Teva’s argument has some intuitive appeal,” J.A. at 181, under

this court’s precedents, a preference for COX-2 selectivity was “not an aspect of using

the claimed compounds or compositions that materially affects the properties of the

claimed inventions,” because it did not “affect the intrinsic properties of the claimed

invention or teach anything that must be done to the compounds or compositions in

order to make them work.” J.A. at 184.

Pfizer argues that the district court correctly construed our precedent as

foreclosing the possibility that the best mode requirement demands the disclosure of

such a preference. It argues that, under Bayer, the best mode inquiry is limited to

determining whether the patent conceals a preference for making or using the claimed

invention. And, according to Pfizer, because there is no dispute that one of ordinary

skill in the art would know how to make and use the claimed compositions and

compounds themselves, there can be no best mode violation.

2007-1271 19
 These contentions as to the generic claims raise a difficult issue that we need not

resolve to decide this case. This is so because we undertake the best mode inquiry on

a claim by claim basis, and we conclude that the celecoxib-specific claims are not

invalid.

Claim 9 of the ’823 patent and claim 17 of the ’165 patent are both celecoxib-

specific claims; they each disclose only one compound/composition. Here, there is no

issue as to these claims about failing to disclose the preferred compound or

composition because these claims are directed to a single compound and composition.

There is thus no failure to disclose a preferred embodiment or a preference for

identifying the preferred embodiment with respect to these claims. Teva’s sole

argument is that, even after identifying the compound celecoxib, the criteria for selecting

the correct dosage requires knowledge of Pfizer’s preference for COX-2 selectivity, and

that under Bayer there is failure to disclose a preferred way of using the invention.

Pfizer does not appear to dispute that dosage range could be a preferred method of use

that materially affects the properties of the invention under Bayer. But Pfizer counters

that dosages were disclosed in the specification, and that there was no evidence that

the inventors preferred another dosage. This appears to be undisputed. Teva’s only

answer to this is that COX-2 selectivity could affect dosage. Although Teva is correct,

there is no evidence that at the time of filing the inventors planned to use the COX-2

selectivity criterion to arrive at a preferred dosage (in contrast to their intent to use COX-

2 selectivity to arrive at the right compounds). Thus, there was no evidence that they

concealed a preferred method of getting to the right dosage. We thus hold that at least

the celecoxib-specific claims in the ’823 and ’165 patents did not violate the best mode

2007-1271 20
requirement. We affirm the district court’s judgment that these claims are not invalid

and are infringed.

Having concluded that these claims are valid, we need not address the generic

claims. There is no counterclaim for invalidity in this case, see Cardinal Chem. Co. v.

Morton Int’l, Inc., 508 U.S. 83 (1993), and a finding that the other claims were invalid

would not change the practical effect of the district court’s judgment since the order is

directed to the use of celecoxib. In other words, it makes no practical difference whether

Teva’s ANDA filing infringes other claims in the ’823 and ’165 patents.

III

Teva next contends that the patents in suit are unenforceable due to inequitable

conduct. A patent will not be held unenforceable due to inequitable conduct unless

there is clear and convincing evidence that the patent applicant (1) either “made an

affirmative misrepresentation of material fact, failed to disclose material information, or

submitted false material information, and (2) intended to deceive the [PTO].” Cargill,

Inc. v. Canbra Foods, Ltd., 476 F.3d 1359, 1363 (Fed. Cir. 2007). If it finds materiality

and intent, a district court must then "balance the equities to determine whether the

patentee has committed inequitable conduct that warrants holding the patent

unenforceable." Id. at 1365. We review a district court’s findings on the threshold

issues of materiality and intent for clear error, and the ultimate decision on inequitable

conduct for abuse of discretion. Id. at 1364-65.

“Information is material for the purposes of an inequitable conduct determination

if a reasonable examiner would have considered such prior art important in deciding

whether to allow the parent application.” Digital Control, Inc. v. Charles Mach. Works,

2007-1271 21
437 F.3d 1309, 1314 (Fed. Cir. 2006) (internal citation omitted). We have noted that

under the “reasonable examiner” standard, “a misstatement or omission may be

material even if disclosure of that misstatement or omission would not have rendered

the invention unpatentable.” Id. at 1318.

Before the district court, Teva argued that Pfizer had committed inequitable

conduct by failing to disclose two Merck publications during the prosecution of the

applications that led to the patents in suit. These two publications—the ’501 application

and the ’995 patent—both derive from and claim priority to Merck’s U.S. Patent

Application 08/082,196 (“the ’196 application”) filed several months before Pfizer filed its

initial application. The ’196 application was later abandoned and never published, and

could not, therefore, have been used as prior art under 35 U.S.C. § 102 against any of

the patents in suit. The ’501 application was published before the ’823 patent issued;

the ’995 patent issued and was published after the ’823 patent issued but before either

the ’165 patent or the ’068 patent issued. With respect to the ’823 patent, Teva argued

that Pfizer should have disclosed the ’501 application because that would have led a

reasonable examiner to the earlier ’196 application and therefore to the application for

the ’995 patent, which was a CIP of the ’196 application. With respect to the ’165 patent

and the ’068 patent, Teva argues that Pfizer should have disclosed the ’995 patent

itself. There was no dispute that Pfizer was in possession of these two references

during the pendency of its own patent applications.

The district court held that neither the ’501 application nor the ’995 patent was

material. The district court also held that, even if the Merck references were material,

Teva had failed to meet the threshold showing of intent. We conclude that, even if the

2007-1271 22
Merck references were material, the district court did not clearly err in finding that Teva

failed to establish that Pfizer acted with an intent to deceive.

On appeal, Teva contends that the materiality of the references standing alone,

in the absence of a credible explanation for withholding them, is sufficient to establish

intent. However, the district court held that Pfizer had offered a good faith explanation

for failing to disclose the Merck references based on the testimony of Pfizer’s witness,

Dr. Talley, who was one of the named inventors of celecoxib. Dr. Talley testified that

Pfizer had studied the Merck references and concluded that none of the compounds

disclosed in the Merck references was similar to the compounds disclosed in Pfizer’s

own patent applications. This is because, as Dr. Talley explained, the compounds

disclosed in the Merck references had a different heterocyclic core than the compounds

of the Pfizer applications and that this was a significant distinction. Pfizer notes that the

PTO itself recognizes that such differences are significant. Pfizer also presented

evidence below of its own highly consistent pattern of disclosing references having the

same heterocyclic core in the prosecution of hundreds of its other patent applications.

Indeed, Pfizer established that, in connection with the prosecution of a separate patent

application that had the same heterocyclic core, it did disclose the ’501 reference. The

district court credited this “highly consistent pattern” as strong evidence supporting

Pfizer’s good faith explanation for not disclosing the Merck references. Because the

Merck references disclosed compounds having a different core, Pfizer concluded that

they were not material. The district court found that Dr. Talley’s testimony in this

2007-1271 23
respect was credible, and we see no basis for overturning that finding. 11 Given the

existence of a credible reason for the withholding, the materiality of the references

standing alone is not sufficient to establish intent. See Ferring B.V. v. Barr Labs., Inc.,

437 F.3d 1181, 1191 (Fed. Cir. 2006) (requiring three conditions where a party relies

solely on the materiality of the references: “(1) the applicant knew of the information; (2)

the applicant knew or should have known of the materiality of the information; and (3)

the applicant has not provided a credible explanation for the withholding”). For these

reasons, we conclude that the district court did not clearly err in finding that Teva failed

to prove by clear and convincing evidence that Pfizer intended to deceive the PTO by

not disclosing the Merck references. There is therefore no basis for finding inequitable

conduct.

IV

We find that the asserted claims of the ’068 patent are invalid for double

patenting and reverse the district court on that aspect of its judgment. We also find that

claim 9 of the ’823 patent and claim 17 of the ’165 patent are not invalid for a best mode

violation. Finally, the ’823 patent, the ’165 patent, and the ’068 patent are not

unenforceable for inequitable conduct. Accordingly, we affirm the district court’s

judgment of infringement with respect to claim 9 of the ’823 patent and claim 17 of the

’165 patent.

11
Teva argues that the district court improperly restricted its cross-
examination of Dr. Talley by not allowing questions regarding Dr. Talley’s signing of the
oath in the patent application. The district court not only determined that Teva’s line of
questioning went beyond the scope of direct, but it also concluded that the evidence
that Teva wanted to elicit from Dr. Talley was already in the record. We do not find that
this was an abuse of discretion.

2007-1271 24
 CONCLUSION

The judgment of the district court is AFFIRMED-IN-PART and REVERSED-IN-

PART.

No costs.

2007-1271 25