United States Court of Appeals for the Federal Circuit 

06-1613 

SANOFI-SYNTHELABO, SANOFI-SYNTHELABO, INC., 

and BRISTOL-MYERS SQUIBB SANOFI PHARMACEUTICALS HOLDING 

PARTNERSHIP, 

Plaintiffs-Appellees, 

v. 

APOTEX, INC. and APOTEX CORP., 

Defendants-Appellants. 

Evan R. Chesler, Cravath, Swaine & Moore, LLP, of New York, New York, 

argued for plaintiffs-appellees. With him on the brief were Richard J. Stark and David 

Greenwald. Of counsel on the brief were Robert L. Baechtold, John D. Murnane, and 

William E. Solander, Fitzpatrick, Cella, Harper & Scinto, of New York, New York. 

Bruce J. Chasan, Caesar, Rivise, Bernstein, Cohen & Pokotilow, Ltd., of 

Philadelphia, Pennsylvania, argued for defendants-appellants. With him on the brief 

were Robert S. Silver, Manny D. Pokotilow, Mona Gupta, and Lynn M. Terrebonne. 

 

Anthony F. Lo Cicero, Amster, Rothstein & Ebenstein LLP, of New York, New 

York, for amicus curiae, Generic Pharmaceutical Association. With him on the brief was 

Richard S. Mandaro. 

David H. Weinstein, Weinstein Kitchenoff & Asher LLC, of Philadelphia, 

Pennsylvania, for amicus curiae, Medco Health Solutions, Inc. 

Jeffrey Light, Patients Not Patents, Inc., of Washington, DC, for amicus curiae, 

Patients Not Patents, Inc. 

Appealed from: United States District Court for the Southern District of New York 

Judge Sidney H. Stein 
United States Court of Appeals for the Federal Circuit 

06-1613 

SANOFI-SYNTHELABO, SANOFI-SYNTHELABO, INC. 

and BRISTOL-MYERS SQUIBB SANOFI PHARMACEUTICALS HOLDING 

PARTNERSHIP, 

 Plaintiffs-Appellees, 

v. 

APOTEX, INC. and APOTEX CORP., 

Defendants-Appellants. 

_____________________ 

DECIDED: December 8, 2006 

_____________________ 

Before LOURIE, Circuit Judge, CLEVENGER, Senior Circuit Judge, and BRYSON, 

Circuit Judge. 

LOURIE, Circuit Judge. 

Apotex, Inc. and Apotex Corp. (collectively referred to as “Apotex”) appeal from 

the decision of the United States District Court for the Southern District of New York 

granting a preliminary injunction in favor of Sanofi-Synthelabo, Sanofi-Synthelabo, Inc., 

and Bristol-Myers Squibb (“BMS”) Sanofi Pharmaceuticals Holding Partnership 

(collectively referred to as “Sanofi”). Because we conclude that the district court did not 

abuse its discretion in granting the preliminary injunction, we affirm. 
BACKGROUND 

Sanofi markets Plavix®, a platelet aggregation inhibiting agent used to reduce 

thrombotic events such as heart attacks and strokes. The active ingredient in Plavix® is 

clopidogrel bisulfate, which is covered by Sanofi’s patent, U.S. Patent 4,847,265 (“the 

’265 patent”), which will expire on November 17, 2011. 

To understand the issues presented in this appeal, it is necessary to have a 

generalized understanding of stereochemistry. Stereochemistry refers to the threedimensional spatial arrangement of a molecule’s constituent atoms. Molecules that 

have the same chemical substituents, but different spatial arrangements, are referred to 

as stereoisomers. If they contain an asymmetrical carbon atom, they exist as nonsuperimposable mirror images of each other and are referred to as enantiomers. 

Enantiomers are optically active because they are capable of rotating plane-polarized 

light; enantiomers that rotate polarized light to the right are referred to as dextrorotatory 

enantiomers, or d-enantiomers; enantiomers rotating polarized light to the left are 

referred to as levorotatory enantiomers, or l-enantiomers.1

 A mixture of equal amounts 

of both types of enantiomers is referred to as a racemic mixture, or racemate, and it 

exhibits no optical activity. Clopidogrel is the dextrorotatory enantiomer of the free base 

methyl alpha-5-(4,5,6,7-tetrahydro(3,2-c)thienopyridyl)-(2-chlorophenyl) acetate, which 

the parties refer to as “MATTPCA.” The active ingredient in Plavix® is the bisulfate salt 

of the d-enantiomer of MATTPCA, which is specifically recited in claim 3 of the ’265 

patent. 

 1

 Other nomenclature conventions are used to signify dextrorotatory and 

levorotatory enantiomers. For example, the prefixes (R-) or (+) refer to d-enantiomers, 

and (L-) or (-) refer to l-enantiomers. 

06-1613 2
In November 2001, Apotex filed an Abbreviated New Drug Application (“ANDA”) 

pursuant to the Hatch-Waxman Act seeking U.S. Food and Drug Administration (“FDA”) 

approval to manufacture and sell a generic version of clopidogrel bisulfate. Apotex filed 

a Paragraph IV certification with its ANDA, pursuant to 21 U.S.C. § 355(j)(2)(A)(vii)(IV), 

asserting that the ’265 patent is invalid. In response, Sanofi sued Apotex on March 21, 

2002, claiming that the filing of the ANDA infringed the ’265 patent. Apotex 

counterclaimed, asserting that the patent is invalid and unenforceable. A thirty-month 

stay of FDA approval for the ANDA was triggered when the suit was filed in the district 

court, pursuant to 21 U.S.C. § 355(j)(5)(B)(iii). The stay expired May 17, 2005, and on 

January 20, 2006, the FDA approved the ANDA. 

Several days before the ANDA was approved, Sanofi and Apotex began 

settlement negotiations in an effort to resolve the litigation. On March 17, 2006, the 

parties reached a first settlement agreement that was subject to the approval of the 

Federal Trade Commission and a consortium of state attorneys general pursuant to an 

order issued in another litigation involving BMS. In May 2006, the state attorneys 

general notified the parties that they would not approve the settlement. The parties 

negotiated a second agreement (“the May agreement”). The May agreement included 

provisions specifying, inter alia, actions that could be taken by the parties in the event 

that the settlement failed to receive regulatory approval. In July 2006, the state 

attorneys general again informed the parties that they would not approve the settlement. 

Apotex then declared “regulatory denial” on July 31, 2006, as permitted under the 

settlement agreement, which meant, inter alia, “a denial of approval by either the FTC or 

06-1613 3
a state attorney general as to which neither party seeks further review.” Under the 

agreement, litigation would resume in the event of “regulatory denial.” 

Pursuant to the aforementioned agreement, Apotex launched its generic 

clopidogrel bisulfate product on August 8, 2006. In accordance with the provisions in 

the settlement agreement, Sanofi notified Apotex of its intent to move for a preliminary 

injunction in the time frame permitted by the agreement, viz., five business days after 

the generic launch.2

 Sanofi filed its motion for a preliminary injunction on August 15, 

2006, and requested a recall of Apotex’s products that were already distributed. After a 

two-day evidentiary hearing, the district court granted the motion for injunctive relief on 

August 31, 2006, but denied the request for recall. During the period between the 

generic launch and the entry of the preliminary injunction, Apotex shipped a six-month 

supply of its product to distributors in the United States. 

In reaching its decision, the district court applied the established four-factor test 

for preliminary injunctive relief, and found that the factors weighed in favor of an 

injunction. Regarding the likelihood of success on the merits, the court noted that 

Apotex conceded that its accused products infringe claim 3 of the ’265 patent. The 

court then found that Apotex failed to establish a likelihood of proving invalidity at trial—

rejecting its anticipation, obviousness, and obviousness-type double patenting invalidity 

defenses. The court also determined that Apotex failed to raise a substantial question 

as to whether the ’265 patent is unenforceable due to inequitable conduct. Additionally, 

the court found that the remaining three factors of the test favored issuance of a 

 2

 Sanofi moved for a temporary restraining order (“TRO”) prior to that date, but 

the request was denied in light of Sanofi’s agreement not to seek a TRO before the 

expiration of the five-day period. Sanofi-Synthelabo v. Apotex, No. 02-2255, slip op. at 

10 (S.D.N.Y. Aug. 31, 2006). 

06-1613 4
preliminary injunction. As for Apotex’s other defenses, the court concluded that the 

doctrine of laches was inapplicable, and it rejected Apotex’s unclean hands defense. 

The court set bond in the amount of $400 million. Trial is scheduled to commence on 

January 22, 2007. 

Apotex moved for a stay of the injunction, which we denied on September 21, 

2006, and it filed its appeal from the district court’s grant of the preliminary injunction. 

An expedited briefing schedule was set, and oral argument was heard on October 31, 

2006. We have jurisdiction pursuant to 28 U.S.C. § 1292(c) in view of §§ 1292(a) and 

1295(a)(1). 

DISCUSSION 

A decision to grant or deny a preliminary injunction pursuant to 35 U.S.C. § 283 

is within the sound discretion of the district court, and we review such a decision for an 

abuse of discretion. Amazon.com, Inc. v. Barnesandnoble.com, Inc., 239 F.3d 1343, 

1350 (Fed. Cir. 2001). Thus, a decision granting a preliminary injunction will be 

overturned on appeal only if it is established “that the court made a clear error of 

judgment in weighing relevant factors or exercised its discretion based upon an error of 

law or clearly erroneous factual findings.” Genentech, Inc. v. Novo Nordisk A/S, 108 

F.3d 1361, 1364 (Fed. Cir. 1997). To the extent the court’s decision is based upon an 

issue of law, we review that issue de novo. Tate Access Floors, Inc. v. Interface 

Architectural Res., Inc., 279 F.3d 1357, 1364 (Fed. Cir. 2002). 

Sanofi, as the moving party, may be entitled to a preliminary injunction if it 

establishes four factors: “(1) a reasonable likelihood of its success on the merits; (2) 

irreparable harm if an injunction is not granted; (3) a balance of hardships tipping in its 

06-1613 5
favor; and (4) the injunction’s . . . impact on the public interest.” Amazon.com, 239 F.3d 

at 1350. 

A. Likelihood of Success on the Merits

In order to satisfy the first element of the test, Sanofi must demonstrate that, “in 

light of the presumptions and burdens that will inhere at trial on the merits,” 

Amazon.com, 239 F.3d at 1350, Sanofi will likely prove that Apotex’s product infringes 

the ’265 patent and that it will withstand Apotex’s challenges to the validity and 

enforceability of the ’265 patent. Because Apotex stipulated to infringement, only the 

second inquiry is at issue in this case. Thus, the first element was properly found 

satisfied if Apotex failed to raise a “substantial question” with regard to the validity or 

enforceability of the ’265 patent—or, if it succeeded in doing so, Sanofi demonstrated 

that those defenses “lack substantial merit.” Genentech, 108 F.3d at 1364. On appeal, 

Apotex challenges the district court’s rulings with respect to anticipation, obviousness, 

obviousness-type double patenting, and enforceability. 

1. Validity of the ’265 Patent

a. Anticipation

We first consider whether the district court clearly erred in its determination that 

Sanofi will likely withstand Apotex’s challenge to the validity of the ’265 patent based on 

anticipation. Apotex asserted that U.S. Patent 4,529,596 (“the ’596 patent”) anticipates 

claim 3 of the ’265 patent. The district court rejected Apotex’s argument on two 

grounds. First, the court found that the ’596 patent does not describe clopidogrel 

bisulfate. Second, the court determined that the ’596 patent does not enable a person 

of ordinary skill in the art to make clopidogrel bisulfate without undue experimentation. 

06-1613 6
On appeal, Apotex argues that the district court erred by improperly focusing its 

anticipation analysis on claim 1 of the ’596 patent, which claims a broad genus of 

compounds, and by failing to consider claim 2, which claims the free base of 

clopidogrel, MATTPCA. According to Apotex, claim 2 describes clopidogrel bisulfate 

and thus anticipates claim 3 of the ’265 patent.3

 Apotex advances two main arguments 

in support of this position. First, Apotex argues that a person of ordinary skill in the art 

would interpret claim 2 of the ’596 patent in light of the specification as not only 

disclosing the racemate free base, but also the dextrorotatory and levorotatory 

enantiomers, as well as pharmaceutically acceptable salts, including the bisulfate. 

Second, Apotex contends that the district court erred by failing to address controlling 

precedent, specifically In re Petering, 301 F.2d 676 (C.C.P.A. 1962), and In re 

Schaumann, 572 F.2d 312 (C.C.P.A. 1978), which relate to genus/species anticipation. 

According to Apotex, those cases establish that the genus disclosed in claim 2 of the 

’596 patent is a small class to which clopidogrel bisulfate belongs, which describes all 

members of that class. 

Sanofi responds that the district court correctly concluded that Apotex’s 

anticipation challenge lacks substantial merit. Sanofi contends that Apotex engages in 

an impermissible, hindsight-driven, “dissection and recombination” analysis of the ’596 

specification in arguing that a person of ordinary skill in the art would interpret the claim, 

which only recites the racemate free base, as disclosing the bisulfate salt of the d-

 3

 In this appeal, we are faced with the unusual situation of an anticipating 

disclosure being argued to be a claim, rather than other descriptive material in a 

specification. No doubt appellants argued what they considered to be their strongest 

case. 

06-1613 7
enantiomer. Sanofi further argues that the district court did not abuse its discretion in 

not addressing Petering because it does not apply in this case. 

As a preliminary matter, we note that the ’596 patent was before the Examiner 

during prosecution, which makes Apotex’s burden of proving invalidity at trial “especially 

difficult.” Glaxo Group Ltd. v. Apotex, Inc., 376 F.3d 1339, 1348 (Fed. Cir. 2004). Thus, 

in light of the deferential standard we apply in reviewing grants or denials of preliminary 

injunctions, and mindful that “a patent is presumed valid, and this presumption exists at 

every stage of the litigation,” Canon Computer Sys., Inc. v. Nu-Kote Int’l., Inc., 134 F.3d 

1085, 1088 (Fed. Cir. 1998), we conclude that the district court did not clearly err in 

finding that Apotex’s anticipation defense lacks substantial merit.4

 

A determination that a patent is invalid as being anticipated under 35 U.S.C. 

§ 102 requires a finding that “each and every limitation is found either expressly or 

inherently in a single prior art reference.” Celeritas Techs. Ltd. v. Rockwell Int'l Corp., 

150 F.3d 1354, 1361 (Fed. Cir. 1998). Claim 3 of the ’265 patent reads as follows: 

3. Hydrogen sulfate of the dextro-rotatory isomer of methyl 

alpha-5 (4,5,6,7-tetrahydro (3,2-c) thienopyridyl) (2-

chlorophenyl) - acetate substantially separated from the 

levo-rotatory isomer. 

’265 patent col.12 ll.37-40. Thus, the claim consists of the following key limitations: 1) 

the d-enantiomer; 2) of the compound MATTPCA; 3) the bisulfate salt; and 4) 

substantial separation from the levorotatory isomer. 

 4

 In its moving brief and as counsel clarified at oral argument, Apotex’s 

anticipation argument on appeal is solely premised on claim 2 of the ’596 patent. Thus, 

we limit our discussion to the narrow issue whether there is substantial merit to Apotex’s 

assertion that claim 3 of the ’265 patent is unpatentable in view of claim 2 of the ’596 

patent. 

 

06-1613 8
Claim 2 of the ’596 patent, in contrast, reads as follows: 

2. Methyl α-(4,5,6,7-tetrahydro-thieno(3,2-c)-5-pyridyl)-

o.chlorophenyl-acetate.5

’596 patent, col.13, ll.20-21. Thus, the plain language of claim 2 only recites the free 

base, MATTPCA, and does not expressly describe the dextrorotatory or levorotatory 

enantiomers or any salt. Because claim 2 fails to describe each and every limitation of 

claim 3 on its face, claim 2 does not anticipate claim 3. 

Apotex argues that the two missing limitations, viz., the d-enantiomer and the 

bisulfate salt, are inherently disclosed in the claim. With regard to the bisulfate salt 

limitation, Apotex seeks to import into the scope of claim 2 a statement in the 

specification that the invention includes “addition salts with pharmaceutically acceptable 

mineral or organic acids.” Id., col.1 ll.42-43. Apotex further argues that the ’596 patent 

discloses a preference for bisulfate salt. 

The district court, however, considered that argument and rejected it. After 

careful consideration of the record before it, the court found that a person of ordinary 

skill in the art would not be led to the bisulfate salt for several reasons. Based on the 

testimony of Sanofi’s expert, Dr. Byrn, the court noted that a chemist would actually be 

dissuaded from preparing the bisulfate salt in light of Example 1, which describes the 

hydrochloride salt of the racemate, because a chemist would believe that the 

hydrochloride, as opposed to the bisulfate, is the preferred salt for clopidogrel. The 

 5

 The parties do not dispute that “methyl α-(4,5,6,7-tetrahydro-thieno(3,2-c)-5-

pyridyl)-o.chlorophenyl-acetate” recited in claim 2 of the ’596 patent is the same 

compound as “methyl alpha-5 (4,5,6,7-tetrahydro (3,2-c) thienopyridyl) (2-chlorophenyl)-

acetate” recited in claim 3 of the ’265 patent. Both names, although slightly different in 

form, refer to the same free base, MATTPCA. The punctuation of the names is as it 

appears in the particular patents. 

06-1613 9
court also credited Dr. Byrn’s additional testimony that salt formation with a new 

compound is an “unpredictable exercise.” In addition, the court noted that a chemist 

theoretically had at least fifty different pharmaceutically acceptable salts from which he 

could have chosen for formulation. Based on that evidence, the court found that 

“disclosing bisulfate in the ’596 patent was insufficient to disclose a single enantiomer of 

a compound as a bisulfate salt.” Sanofi-Synthelabo, slip op. at 26. Because we find 

that the district court did not clearly err in its fact-finding as to this issue, we reject 

Apotex’s argument that claim 2 of the ’596 patent inherently discloses the bisulfate salt.6

 

Apotex argues that the holding in In re May, 574 F.2d 1082 (C.C.P.A 1978), 

specifically with respect to claim 6—a claim that the Court of Customs and Patent 

Appeals found anticipated by prior art—mandates a finding of anticipation here. That 

case, however, is distinguishable from this case. In May, our predecessor court held 

that claim 6, which claimed the hydrochloride salt of a class of compounds, or genus, 

was anticipated by a prior art patent that expressly disclosed the hydrobromide salt of a 

species included within the genus. The appellant argued that the prior art patent did not 

anticipate the hydrochloride because it did not “specifically describe” it. The court 

disagreed in light of a statement in the specification that the compounds of the genus 

were “preferably administered in the form of their salts, ‘the hydrobromide and 

hydrochloride salts being especially suitable.’” Id. at 1090 (emphases added). The 

court found that that statement “coupled with the express disclosure of the 

 6

 Apotex cites In re Adamson, 275 F.2d 952, 954 (C.C.P.A. 1960), for the 

proposition that the disclosure of a racemic compound inherently discloses its 

enantiomers. Thus, Apotex argues that the d-enantiomer of MATTPCA is inherently 

disclosed by claim 2. Because we conclude that the district court did not err in finding 

that the bisulfate salt limitation is not disclosed in the claim, and thus cannot anticipate 

claim 3, we need not address this contention. 

06-1613 10
hydrobromide salt of the [species compound]” constituted an anticipation of claim 6. Id. 

Here, however, there is no clear statement in the specification that the bisulfate salt is 

“especially suitable” for administering compounds of the genus including clopidogrel. 

On the contrary, as discussed above, the specification of the ’596 patent discloses a 

number of potentially acceptable salts and discloses the racemate of clopidogrel in 

Example 1 only as a hydrochloride salt. Thus, we find the facts in the present case 

distinguishable from those in May. 

Further, we are not persuaded by Apotex’s argument that the holdings of In re 

Petering and In re Schaumann warrant reversal of the district court’s decision. In 

Petering, the Court of Customs and Patent Appeals upheld the board’s § 102(b) 

anticipation rejection of a claim that covered specific chemical compounds in light of a 

prior art patent that disclosed a class of compounds of which those specific compounds 

were members. 301 F.2d at 682. In reaching its conclusion, the court noted that, while 

the generic formula in Petering was quite broad, “specific preferences” were described. 

Based on those disclosed preferences, the court found that the narrowed generic 

formula essentially disclosed a limited class of approximately twenty compounds. Each 

was held to have been disclosed by the genus. 

Similarly, in Schaumann, the Court of Customs and Patent Appeals affirmed the 

rejection of claims that covered a specific compound and certain compatible salts in 

light of a prior art patent that disclosed a generic formula with a single variable. The 

court found that the prior art patent disclosed a limited class of compounds based on a 

disclosed preference for that variable substituent. The court concluded that the 

06-1613 11
compound in the rejected claim fell within the scope of that limited class of compounds, 

and thus was anticipated by the prior art patent. 

Here, however, we do not find that the ’596 patent discloses a “pattern of 

preferences” akin to the disclosures in Petering and Schaumann that would limit the 

generic formula of MATTPCA in claim 2 of the ’596 patent to a narrow class of 

compounds that includes clopidogrel bisulfate. The principal, obvious distinction is that 

the generic formula of claim 2 does not include a salt. On this basis alone, we find that 

clopidogrel bisulfate is not a species of any genus comprised by claim 2 of the ’596 

patent. 

In addition, our predecessor court found a “pattern of preferences” in Petering

and Schaumann. In this case, however, there is no such clear “pattern of preferences” 

that serves to narrow the genus in claim 2 to a narrow class that includes clopidogrel 

bisulfate. Even had claim 2 included salts generically, there was no expressed 

preference for clopidogrel bisulfate. The ’596 patent specification discloses twenty-one 

exemplary compounds that are thienopyridines—not just MATTPCA. The examples 

describe hydrochloride salts, hydrobromide salts, a sodium salt, an oxalate, and a free 

base, as well as bisulfates, not showing a preference for bisulfates. Thus, we find this 

case distinguishable from Petering and Schaumann on that additional basis, viz., that 

the ’596 patent does not point to bisulfates as preferred salts for clopidogrel. 

We therefore reject Apotex’s assertion that clopidogrel bisulfate is a species of 

the genus in claim 2 of the ’596 patent, and that the district court clearly erred by failing 

to so find. In light of this holding, we need not address the enablement issue. 

Accordingly, we conclude that the district court did not clearly err in finding no 

06-1613 12
substantial merit to Apotex’s assertion that claim 3 of the ’265 patent is anticipated by 

the ’596 patent.7

 

b. Obviousness

We next consider Apotex’s assertion that claim 3 of the ’265 patent is invalid as 

obvious. Apotex argues that the district court erred in concluding that its obviousness 

defense failed to raise a substantial question with regard to the validity of the ’265 

patent. Apotex primarily argues that it would have been obvious to a person of ordinary 

skill in the art to prepare clopidogrel bisulfate based on the disclosure of the ’596 patent. 

Additionally, Apotex asserts that the “unexpected results” upon which Sanofi relied to 

establish the nonobviousness of clopidogrel bisulfate were not “unexpected” to a person 

of ordinary skill in the art. Moreover, Apotex contends that the court erred by failing to 

cite Adamson in its obviousness analysis—a case that, according to Apotex, stands for 

the proposition that enantiomers are prima facie obvious over disclosures of their 

racemates. 

Sanofi responds that the district court correctly concluded that it would not have 

been obvious to prepare clopidogrel bisulfate in view of the ’596 patent, particularly in 

light of the effort Sanofi actually had to expend in developing clopidogrel bisulfate, 

including the four years and millions of dollars that were allocated to the development of 

the racemate before efforts were redirected toward isolating the d-enantiomer. Sanofi 

 7

 To the extent that Apotex argues that portions of the ’596 patent other than 

claim 2 anticipate clopidogrel bisulfate, we reject that argument. Although several of the 

examples in the ’596 patent are salts of esters, the specification does not identify as a 

class esters in salt form. This case is therefore unlike Petering, in which the prior art 

reference named a class, examples of which were then taken as expressing preferred 

species of that class. Similarly, because no class-wide salt preferences are disclosed, 

May does not support a finding of anticipation. 

06-1613 13
further argues that any prima facie obviousness resulting from the disclosure of the 

racemate in the prior art was rebutted by the unexpected properties of clopidogrel 

bisulfate—specifically, high pharmacological activity and low toxicity—two properties 

that are not necessarily generally associated with one enantiomer. 

We agree with Sanofi that the court did not clearly err in finding that Apotex failed 

to raise a substantial question in its obviousness defense. First, we reject Apotex’s 

contention that it would have been obvious to a person of ordinary skill in the art to 

prepare clopidogrel bisulfate based on the disclosures of the ’596 patent. The district 

court rejected that position after considering extensive argument, testimony, and 

references presented by both parties. In reaching that determination, the district court 

noted that there was “nothing obvious about arriving at clopidogrel bisulfate by 

separating the enantiomers of [MATTPCA] and preparing the dextrorotatory 

[enantiomer] as a bisulfate salt.” Sanofi-Synthelabo, slip op. at 31-32. The court 

determined that nothing existed in the prior art that would make pursuing the 

enantiomer of MATTPCA an obvious choice, particularly in light of the unpredictability of 

the pharmaceutical properties of the enantiomers and the potential for enantiomers to 

racemize in the body. 

The court also found that the extensive time and money Sanofi spent developing 

the racemate before redirecting its efforts toward the enantiomer, and the 

unpredictability of salt formation, were indicators of nonobviousness. The court credited 

the testimony of Apotex’s own expert, Dr. McClelland, who agreed that salt formation 

was an unpredictable exercise that would require a chemist “to engage in 

experimentation to determine which salt would in fact be suitable.” Id. at 33. The court 

06-1613 14
also noted that a named inventor, Dr. Badorc, tested twenty different salts before 

discovering that bisulfate had the most desirable properties. Thus, the court found that 

it would not have been obvious to a person of ordinary skill in the art to prepare 

clopidogrel bisulfate from reading the ’596 patent in light of the extensive 

experimentation that was required to arrive at that particular compound. We discern no 

clear error with respect to those factual determinations or the legal conclusion. 

We also reject Apotex’s assertion that a person of ordinary skill in the art would 

have been led to the active enantiomer of MATTPCA after reading the ’596 patent. 

Apotex merely asserts that one would have been motivated “because the patent directs 

[a person of ordinary skill in the art] to enantiomers and pharmaceutical salts.” We have 

noted that it is insufficient to merely identify each element in the prior art to establish 

unpatentability of the combined subject matter as a whole. Abbott Labs. v. Andrx 

Pharm., Inc., 452 F.3d 1331, 1336 (Fed. Cir. 2006). Instead, “a party alleging invalidity 

due to obviousness must articulate the reasons one of ordinary skill in the art would 

have been motivated to select the references and to combine them to render the 

claimed invention obvious.” Id. Apotex’s conclusory assertion that the ’596 patent 

directs a chemist to the enantiomers and salts is insufficient to satisfy this requirement. 

Certainly nothing directed a chemist to the particular enantiomer and salt, clopidogrel 

bisulfate, which is the limited subject matter of claim 3. 

Second, while Apotex disagrees with the district court’s assessment of the 

evidence relating to the “unexpected results” obtained with clopidogrel bisulfate, we 

review that assessment, which is based on factual findings made by the district court, 

06-1613 15
for clear error. Based on the record before us, we find no basis to conclude that the 

district court clearly erred in its evaluation of that evidence. 

Finally, we are unpersuaded by Apotex’s argument that the court clearly erred by 

failing to consider Adamson in its obviousness analysis. In Adamson, the CCPA 

affirmed the Board’s rejection of claims that covered the l-enantiomer of a specific 

compound and its addition salts as obvious in view of certain prior art references. One 

prior art reference disclosed “synthetically produced compounds of the same formula 

claimed,” but did not state whether the compounds were racemic mixtures or 

enantiomers. Adamson, 275 F.2d at 953. Another prior art reference, an organic 

chemistry textbook, taught, inter alia, that racemates may be separated into their 

enantiomers by various methods, and that enantiomers often possess substantially 

different physiological properties in comparison to each other. Thus, the court found the 

claimed l-enantiomer salt unpatentable despite the fact that that enantiomer exhibited 

substantially greater spasmolytic activity than its dextrorotatory counterpart. 

Apotex contends that Adamson is “no different” from the present case. We 

disagree. This case is distinguishable on at least two grounds. First, it was undisputed 

in Adamson that the primary reference disclosed the racemic mixtures of the isomers 

and the acid addition salts. Id. at 954. Here, and most importantly, the ’596 patent 

does not disclose the bisulfate salt of the d-enantiomer of MATTPCA. Resolution of a 

racemic free base does not lead to a particular unnamed salt. Second, the Adamson

court observed that it would have been expected by one of skill in the art that 

enantiomers would have different pharmacological activity and that the toxicity of the 

racemate would lie somewhere between that of its isomers. In this case, the district 

06-1613 16
court made factual findings that resolving the racemate was not mere routine 

experimentation and that it was unexpected that the desirable activity of clopidogrel 

would be found only in the d-enantiomer. We do not consider that those findings are 

clearly erroneous. Accordingly, Adamson is distinguishable on that additional basis. 

Based on the preliminary record before us, we thus find that the district court did 

not err in determining that Apotex failed to raise a substantial question as to the validity 

of claim 3 based on obviousness. 

c. Obviousness-Type Double Patenting 

In the district court, Apotex also challenged the validity of claim 3 of the ’265 

patent based on obviousness-type double patenting. Apotex argues that the court 

committed clear error in concluding that the double patenting inquiry was subsumed by 

the broader obviousness inquiry, and by failing to specifically address this claim. 

Apotex asserts that an obviousness inquiry is distinct from the double patenting inquiry 

and should have been independently analyzed. Sanofi responds that the court correctly 

concluded that nothing in the prior art, including the ’596 patent, rendered claim 3 

obvious. Claim 2 of the ’596 patent especially did not render claim 3 obvious. 

While Apotex asserts that the court erred by failing to separately address its 

double patenting defense, Apotex fails to set forth any arguments on appeal that raise a 

substantial question with respect to the validity of claim 3 based on that defense. 

Accordingly, we reject Apotex’s argument that the grant of the preliminary injunction 

should be reversed on that basis. 

06-1613 17
2. Enforceability of the ’265 Patent

Apotex argues that the district court abused its discretion in finding that Apotex 

failed to raise a substantial question as to the enforceability of the ’265 patent. Apotex 

identifies separate bases upon which it asserts inequitable conduct should have been 

found. They include incorrect inventorship, concealment of research regarding other 

compounds that were tested by Sanofi, and purported false statements concerning the 

“unexpected results” of clopidogrel bisulfate and the “less well-tolerated” statement 

referring to the l-enantiomer. Sanofi responds to each of Apotex’s assertions, 

explaining why none of Apotex’s arguments raises a substantial question as to the ’265 

patent’s enforceability. 

“A patent may be rendered unenforceable for inequitable conduct if an applicant, 

with intent to mislead or deceive the examiner, fails to disclose material information or 

submits materially false information to the PTO during prosecution.” Digital Control, Inc. 

v. Charles Mach. Works, 437 F.3d 1309, 1313 (Fed. Cir. 2006). “The party asserting 

inequitable conduct must prove a threshold level of materiality and intent by clear and 

convincing evidence.” Id. Further, “materiality does not presume intent, which is a 

separate and essential component of inequitable conduct.” GFI, Inc. v. Franklin Corp., 

265 F.3d 1268, 1274 (Fed. Cir. 2001) (quoting Manville Sales Corp. v. Paramount Sys., 

Inc., 917 F.2d 544, 552 (Fed. Cir. 1990)). 

While Apotex devotes a significant portion of its briefs to argue its inequitable 

conduct contentions, virtually none of its discussion is devoted to identifying any 

evidence that would support a finding of deceptive intent. Apotex’s evidence of intent is 

limited to a statement in Apotex’s reply brief that the inventors’ declaration, which 

06-1613 18
excluded Dr. Maffrand as an inventor, is evidence of intent. Moreover, Apotex suggests 

that intent can be inferred because “Sanofi was motivated to extend its patent monopoly 

beyond the ’596 patent term by patenting the enantiomer, and it needed to conjure up 

‘unexpected’ results.” Such generalized allegations lack the particularity required to 

meet the threshold level of deceptive intent necessary for a finding of inequitable 

conduct. Thus, based on the record before us, Apotex clearly fails to raise a substantial 

question as to the enforceability of the ’265 patent.8

 Accordingly, we find no abuse of 

discretion with regard to that issue. 

B. Other Preliminary Injunction Factors

We next consider the remaining elements of the preliminary injunction test. The 

district court applied a presumption of irreparable harm in light of its conclusion that 

Sanofi established a likelihood of success on the merits. The court also found that 

Sanofi proffered substantial evidence establishing other forms of irreparable harm, 

including irreversible price erosion, loss of good will, potential lay-offs of Sanofi 

employees, and the discontinuance of clinical trials that are devoted to other medical 

uses for Plavix®. 

Apotex argues that the district court clearly erred in concluding that Sanofi would 

suffer irreparable harm in the absence of an injunction. According to Apotex, the 

settlement agreement entered into by Sanofi and Apotex negated any finding of 

irreparable harm. Apotex contends that Sanofi quantified in the May agreement the 

measure of harm it would suffer in the event Apotex marketed a generic product—

 8

 Because both materiality and intent are required to establish inequitable 

conduct, we need not address the materiality of the purported false statement or 

omissions that Apotex describes in its briefs. 

06-1613 19
specifically, 40%-50% of Apotex’s net sales. Additionally, Apotex challenges the court’s 

findings with regard to the other kinds of irreparable harm established by Sanofi. 

In response, Sanofi argues that it did not contractually surrender its right to prove 

irreparable harm by entering into the May agreement. Moreover, Sanofi asserts that the 

court did not clearly err by crediting the evidence it proffered establishing the additional 

kinds of irreparable harm it would suffer if Apotex were allowed to continue selling its 

generic product. 

We conclude that the district court did not clearly err in finding that Sanofi 

satisfied this factor. We are not persuaded by Apotex’s assertion that Sanofi contracted 

away its right to prove irreparable harm by entering into the May agreement, which 

includes a provision that capped damages for infringement by Apotex. In support of this 

argument, Apotex refers to the following provision: 

14. In the event of Regulatory Denial, the litigations will be 

resumed as further described in paragraph 15 hereof, and: 

* * * 

(ii) If the litigation results in a judgment that the ’265 patent 

is not invalid or unenforceable, Sanofi agrees that its actual 

damages for any past infringement by Apotex, up to the date 

on which Apotex is enjoined, will be 50% of Apotex’s net 

sales of clopidogrel products if Sanofi has not launched an 

authorized generic and 40% of Apotex’s net sales if Sanofi 

has launched an authorized generic. Sanofi further agrees 

that it will not seek increased damages under 35. U.S.C. § 

284. 

May agreement, ¶ 14. 

We think that the above provision favors Sanofi, not Apotex. We disagree with 

Apotex that by entering into that agreement, Sanofi bargained away its right to seek 

preliminary injunctive relief, and thus its right to prove irreparable harm, in the event the 

settlement was not approved. The above provision itself contemplates an injunction in 

06-1613 20
referring to “up to the date on which Apotex is enjoined” and speaks only of damages 

for past infringement. In addition, based on other provisions in the agreement, it is clear 

that the parties contemplated the possibility of a preliminary injunction in the event of 

regulatory denial. Paragraph 15 of the agreement, for example, sets forth the 

procedural steps the parties must follow when seeking a preliminary injunction. 

Moreover, merely because a patentee is able to identify a monetary amount that it 

deems sufficient to avoid or end litigation does not necessarily mean that it 

automatically foregoes its right to seek a preliminary injunction or that any potential 

irreparable injury ceases to exist if infringement resumes. Thus, Apotex’s argument is 

unsound. 

Further, we reject Apotex’s assertion that the district court abused its discretion in 

concluding that Sanofi would suffer irreversible price erosion if an injunction were not 

entered. Based on the evidence Sanofi adduced, including the testimony of its 

economics expert, Professor Hausman, and a declaration from a Sanofi executive, 

Hugh O’Neill, the court found that Sanofi would suffer irreversible price erosion in light 

of a complex pricing scheme that is directly affected by the presence of the generic 

product in the market. In particular, the court found that since Apotex’s generic product 

entered the market, Sanofi has been forced to offer discounted rates and price 

concessions to third-party payors, such as health maintenance organizations, in order to 

keep Plavix® on a favorable pricing tier, which governs what consumers pay for that 

drug. The court found that the availability of a generic product encourages third party 

payors to place Plavix® on a less favorable tier, thereby requiring consumers to pay a 

higher co-pay, and perhaps deterring them from purchasing Plavix®. The court 

06-1613 21
identified additional consequences of unfavorable tier placement, including a decrease 

in demand for Plavix®. According to Sanofi, it is nearly impossible to restore Plavix® to 

its pre-launch price since the generic product entered the market. 

Apotex does not argue that price erosion is not a valid ground for finding 

irreparable harm, but rather challenges the district court’s findings as to price erosion. 

We conclude that the district court did not clearly err in its evaluation of the evidence 

relating to price erosion. While Apotex asserts that price erosion had already occurred, 

and thus an injunction is not necessary because it cannot ameliorate Sanofi’s position, 

Apotex fails to identify clear errors in the district court’s analysis, and fails to proffer 

evidence of its own sufficient to rebut the court’s findings. Apotex also fails to 

demonstrate that the court clearly erred in its findings with respect to the additional 

factors that established irreparable harm, including loss of good will, the potential 

reduction in work force, and the discontinuation of clinical trials. Accordingly, we 

conclude that the district court did not clearly err in finding irreparable harm.9

 

As to the third factor of the test, Apotex argues that the court erred in balancing 

the hardships because it ignored the harm Apotex would face if an injunction were 

granted, particularly in light of the settlement agreement which, according to Apotex, 

demonstrates that the harms Sanofi would suffer are a result of its own conduct. Sanofi 

responds that the court did not abuse its discretion in finding that that factor favored 

 9

 Apotex also argues that the district court erred by applying a presumption of 

irreparable harm because Sanofi established a likelihood of success on the merits. 

Apotex contends that applying such a presumption is in direct contravention of the 

Supreme Court’s decision in eBay Inc. v. MercExchange, L.L.C., 126 S. Ct. 1837 

(2006). Because we conclude that the district court did not clearly err in finding that 

Sanofi established several kinds of irreparable harm, including irreversible price erosion, 

we need not address this contention. 

06-1613 22
Sanofi, particularly because it was Apotex’s own decision to engage in an at-risk launch 

that would trigger its 180-day exclusivity period before reaching the merits of the case. 

Based on the record on appeal, we conclude that the court did not clearly err in finding 

that Apotex’s harms were “almost entirely preventable” and were the result of its own 

calculated risk to launch its product pre-judgment. Sanofi-Synthelabo, slip op. at 48. 

Accordingly, the court did not abuse its discretion in finding that the balance of 

hardships tipped in Sanofi’s favor. 

The fourth factor we consider is the public interest, which the court found tips in 

favor of Sanofi, albeit slightly. Apotex, as well as amici,10 argue that the district court 

erred in failing to consider certain public harms that would result if an injunction issues. 

Apotex, in particular, contends that if the generic products were removed from the 

market, consumers would be inclined not to purchase their medication because of the 

accompanying price increase for the brand name drug, leading to possible deaths. 

Apotex further argues that significant consumer confusion may ensue because of the 

six-month supply that was shipped to the American market, which was not equally 

distributed among vendors. Sanofi responds that the court did not clearly err in finding 

that the interest in encouraging pharmaceutical research and development outweighed 

the public interest advanced by Apotex. 

We agree with Sanofi. While Apotex raises legitimate concerns, the district court 

did not abuse its discretion in concluding that those concerns were outweighed by the 

public interests identified by Sanofi. We have long acknowledged the importance of the 

 

10 Medco Health Solutions, Inc., Patients Not Patents, Inc., and the Generic 

Pharmaceutical Association submitted amicus curiae briefs arguing for reversal of the 

grant of the preliminary injunction. 

06-1613 23
patent system in encouraging innovation. Indeed, the “encouragement of investmentbased risk is the fundamental purpose of the patent grant, and is based directly on the 

right to exclude.” Patlex Corp. v. Mossinghoff, 758 F.2d 594, 599 (Fed. Cir. 1985). The 

district court relied on the testimony of Dr. Hausman in finding that the average cost of 

developing a blockbuster drug is $800 million. Importantly, the patent system provides 

incentive to the innovative drug companies to continue costly development efforts. We 

therefore find that the court did not clearly err in concluding that the significant “public 

interest in encouraging investment in drug development and protecting the exclusionary 

rights conveyed in valid pharmaceutical patents” tips the scales in favor of Sanofi. 

Sanofi-Synthelabo, slip. op. at 51. 

C. Unclean Hands

Having concluded that there was no abuse of discretion in the trial judge’s 

determination that the four factors of the preliminary injunction test favor an injunction, 

we next consider Apotex’s argument concerning unclean hands. Apotex argues that the 

district court erred by precluding Apotex from introducing evidence that counsel for BMS 

and Sanofi allegedly engaged in fraudulent misconduct during settlement negotiations 

by concealing oral side agreements from regulators and falsely certifying that such 

agreements did not exist. The district court excluded that evidence from the preliminary 

injunction hearing, reasoning that the “conduct of the parties during settlement 

negotiations does not affect the validity of the patent or the veracity of submissions to 

[the district court], and therefore has no relevance to the question of whether a 

preliminary injunction should issue.” Id. at 55. 

06-1613 24
We conclude that the district court did not abuse its discretion by precluding 

Apotex from asserting this defense. Apotex contends the court clearly erred by 

disregarding Precision Instrument Manufacturing Co. v. Automotive Maintenance 

Machinery Co., 324 U.S. 806 (1945). That case, however, is not on point. There the 

plaintiff sought to enforce several patents and contracts that were obtained as a result 

of a settlement agreement entered into by the parties in order to resolve an interference 

proceeding, during which the parties either committed perjury before the Patent Office 

or concealed their knowledge of the perjury. The Supreme Court applied the unclean 

hands doctrine and dismissed plaintiff’s patent infringement and breach of contract 

claims. In doing so, the Court noted the public policy interest against asserting and 

enforcing patent claims that are “infected with fraud and perjury.” Id. at 819. 

Apotex’s unclean hands defense, however, is not based on fraud or perjury that 

counsel for BMS or Sanofi allegedly committed while obtaining the ’265 patent, but 

instead relates to the settlement agreement entered into between Sanofi and Apotex 

well after the patent was obtained. Because the claims at issue in the grant of the 

preliminary injunction concern infringement and validity of the ’265 patent, as opposed 

to issues relating to the settlement agreement itself, we find that the court did not abuse 

its discretion in excluding such evidence in the context of the preliminary injunction 

motion. See Keystone Driller Co. v. Gen. Excavator Co., 290 U.S. 240, 245 (1933) 

(noting the court’s discretion in applying the unclean hands doctrine when a plaintiff’s 

alleged misconduct “has no relation to anything involved in the suit”). 

06-1613 25
D. Bond

Lastly, Apotex challenges the court’s decision to set bond in the amount of $400 

million, which it asserts fails to provide sufficient security because it represents only 

10% of the annual market and ignores Apotex’s loss of market share. Sanofi responds 

that the amount far exceeds any damage Apotex may face, particularly in light of the 

fact that there was no recall of Apotex’s generic product after it launched its product on 

August 8, 2006. 

The posting of a bond is governed by Federal Rule of Civil Procedure 65(c) which 

provides that: 

No restraining order or preliminary injunction shall issue 

except upon the giving of security by the applicant, in such 

sum as the court deems proper, for the payment of such 

costs and damages as may be incurred or suffered by any 

party who is found to have been wrongfully enjoined or 

restrained. 

Fed. R. Civ. P. 65(c). The amount of a bond is a determination that rests within the 

sound discretion of a trial court. Doctor’s Assocs., Inc. v. Distajo, 107 F.3d 126, 136 (2d 

Cir. 1997) (noting that a district court has wide discretion under Rule 65(c) in setting the 

amount of a bond). The court based its determination on evidence presented before the 

court that concerned Apotex’s “potential lost profits, lost market share and associated 

costs of relaunch” in the event of wrongful enjoinment. Sanofi-Synthelabo, slip op. at 

57. We find no basis for disturbing the court’s assessment of the facts, and thus 

conclude that the court did not abuse its discretion in setting the bond amount. 

CONCLUSION 

We have considered Apotex’s remaining arguments with respect to the myriad of 

issues it has raised on appeal and find them unpersuasive. We therefore conclude that 

06-1613 26
the district court did not abuse its discretion in granting preliminary injunctive relief. 

Accordingly, for the foregoing reasons, we affirm the district court’s grant of the 

preliminary injunction. We wish to note that, while we have carefully considered all of 

the arguments presented to us in reviewing the district court’s grant of the preliminary 

injunction, we have done so in the context of the standard of review applicable to grant 

of preliminary injunctions, and that the district court is not bound to its earlier 

conclusions on full trial on the merits. We leave to that court the conduct of any further 

proceedings. 

AFFIRMED. 

06-1613 27