United States Court of Appeals for the Federal Circuit 

05-1433 

ABBOTT LABORATORIES, 

Plaintiff-Appellee, 

v. 

ANDRX PHARMACEUTICALS, INC., 

and ROXANE LABORATORIES, INC., 

Defendants, 

and 

TEVA PHARMACEUTICALS USA, INC., 

 Defendant-Appellant. 

 Jeffrey I. Weinberger, Munger, Tolles & Olson LLP, of Los Angeles, California, 

argued for plaintiff-appellee. With him on the brief were Ted G. Dane and Andrea Weiss 

Jeffries. Of counsel on the brief were Jennifer L. Polse and Jason Rantanen, of San 

Francisco, California. Of counsel were Todd J. Ehlman and R. Mark McCareins, Winston 

& Strawn LLP, of Chicago, Illinois. 

 James Galbraith, Kenyon & Kenyon, of New York, New York, argued for defendantappellant. With him on the brief were Maria Luisa Palmese and Robert V. Cerwinski. 

Appealed from: United States District Court for the Northern District of Illinois 

Judge David H. Coar 
United States Court of Appeals for the Federal Circuit 

05-1433 

ABBOTT LABORATORIES, 

 Plaintiff-Appellee, 

v. 

ANDRX PHARMACEUTICALS, INC., 

and ROXANE LABORATORIES, INC., 

 Defendants, 

and 

TEVA PHARMACEUTICALS USA, INC., 

 Defendant-Appellant. 

 __________________________ 

DECIDED: June 22, 2006 

 __________________________ 

Before NEWMAN, GAJARSA, and PROST, Circuit Judges. 

Opinion for the court filed by Circuit Judge PROST. Dissenting opinion filed by Circuit 

Judge NEWMAN. 

PROST, Circuit Judge. 

Abbott Laboratories (“Abbott”) brought suit against Teva Pharmaceuticals USA, 

Inc. (“Teva”) alleging infringement of its patents relating to extended release 

formulations of clarithromycin. Abbott moved for a preliminary injunction against Teva 

on the grounds that Teva was infringing claims 2, 4, and 6 of U.S. Patent No. 6,010,718 

(“’718 patent”) and claim 2 of U.S. Patent No. 6,551,616 (“’616 patent”). Teva resisted 
the motion primarily by arguing that substantial questions existed as to the validity of 

Abbott’s asserted claims under 35 U.S.C. § 103. The district court agreed that Teva 

had raised a substantial question as to the validity of claim 2 of the ’616 patent but it 

rejected Teva’s invalidity arguments as to the asserted claims of the ’718 patent. 

Accordingly, the district court granted Abbott’s motion for a preliminary injunction. Teva 

appealed. We have jurisdiction to review the district court’s order under 28 U.S.C. 

§ 1292(c)(1). 

On appeal, Teva has raised substantial issues as to the validity of each of the 

asserted claims relied upon for the preliminary injunction. We vacate the preliminary 

injunction. 

I. 

Clarithromycin is a broad spectrum antibiotic from the macrolide family of 

antibiotics, all of which are derived from erythromycin A. Taisho Pharmaceuticals Ltd. 

received U.S. Patent No. 4,331,803 (“’803 patent”) for clarithromycin in 1982. In 1991, 

Abbott, the exclusive licensee of the ’803 patent, introduced Biaxin, an immediate 

release dosage form of clarithromycin. The ’803 patent expired on May 23, 2005. 

In 1997, Abbott filed for a patent claiming an extended release formulation of 

clarithromycin. The patent describes and claims extended release (“ER”) formulations 

comprising erythromycin derivatives combined with a pharmaceutically acceptable 

polymer. The resulting drug-polymer matrix leads to the extended release properties of 

the formulation. The ER formulation enabled patients to take one pill per day rather 

than twice, as had been required with the immediate release (“IR”) formulation. That 

patent issued on January 4, 2000 as the ’718 patent. Further, based on the ’718 patent 

05-1433 2
application, Abbott filed a continuation-in-part application that claims a method of 

reducing adverse gastrointestinal (“GI”) side effects of erythromycin-derived drug 

formulations by using extended release formulations. This continuation-in-part issued 

as the ’616 patent. In 2000, Abbott introduced its ER clarithromycin formulation, Biaxin 

XL. As of May 2005, Abbott estimated that, as between Biaxin and Biaxin XL, Biaxin XL 

accounted for 70% of sales in the Biaxin market. As the original patent on 

clarithromycin expired on May 23, 2005, generic competitors entered the market for 

immediate release clarithromycin on May 24, 2005. 

In December 2002, Teva filed an Abbreviated New Drug Application (“ANDA”) 

seeking approval to market an extended release form of clarithromycin similar to 

Abbott’s ER clarithromycin drug, Biaxin XL. On March 14, 2005, Abbott sued Teva for 

infringement of the ’718 and ’616 patents.1

 On May 18, 2005, Abbott moved for a 

preliminary injunction against Teva. 

On May 26 and June 1, 2005, the district court held oral argument on Abbott’s 

motion for the preliminary injunction and thereafter, on June 3, issued its memorandum 

opinion. It listed the four factor test for the grant of a preliminary injunction, namely that 

the party seeking the preliminary injunction must show 

(1) the movant has some likelihood of success on the merits of the 

underlying litigation; (2) immediate irreparable harm will result if the relief 

is not granted; (3) the balance of hardships to the parties weighs in the 

movant’s favor; and (4) the public interest is best served by granting the 

injunctive relief. 

 1 Abbott also alleged infringement of U.S. Patent No. 6,872,407 and U.S. 

Patent 4,680,386 but as this case is a limited appeal of the district court’s grant of a 

preliminary injunction under 28 U.S.C. § 1292(c)(1) and that preliminary injunction did 

not extend to the claims of the 6,872,407 or 4,680,386 patent, those two patents are not 

before us today and will not be discussed. 

05-1433 3
Abbott Labs. v. Andrx Pharms., Inc., No. 05-1433, slip op. at 3 (N.D. Ill. June 3, 2005) 

(citing Polymer Techs., Inc. v. Bridwell, 103 F.3d 970, 973 (Fed. Cir. 1996)). The district 

court began its analysis and evaluated Abbott’s likelihood of success on the merits by 

considering Abbott’s infringement contentions and Teva’s invalidity defenses. Teva did 

not dispute that its generic ER formulation of clarithromycin infringed Abbott’s ’718 and 

’616 patent claims. Rather, Teva alleged that the asserted patent claims were invalid 

for obviousness under 35 U.S.C. § 103. The court focused on Teva’s invalidity 

arguments and concluded that Teva had raised a substantial question as to the validity 

of claim 2 of the ’616 patent but it “ha[d] not established that claims 2, 4, and 6 of the 

’718 patent are invalid for obviousness.” Abbott Labs., slip op. at 32. Thus as to the 

asserted claims of the ’718 patent, Abbott had established a likelihood of success on 

the merits. As to irreparable harm, the district court first noted that because of its 

finding that Abbott had proved a likelihood of success on the merits of infringement for 

the ’718 patent claims, there was a presumption of irreparable harm that Teva had to 

rebut. Furthermore, Abbott contended that it will face “irreversible market share losses 

[if] . . . it loses its preferred position on pharmacy and insurance formularies.” Abbott 

Labs., slip op. at 25. As a result, the district court concluded that “entry of the generic 

extended release formulation competitor will likely crush the market” and therefore 

absent the preliminary injunction Abbott would suffer irreparable harm. Abbott Labs., 

slip op. at 27. As to the third factor, the district court stated that Teva was “reluctan[t] or 

inab[le] to quantify the hardship, if any, it will face if an injunction is incorrectly entered” 

and “there is little choice but to conclude that the balance of hardships favors [Abbott].” 

Abbott Labs., slip op. at 30-31. Lastly, the district court determined that “[t]o the extent 

05-1433 4
that this court has found that the patents in suit are valid, the public interest is best 

served by enforcing them.” Id. Based on these considerations, the court issued its 

order entering the preliminary injunction with respect to the asserted claims of the ’718 

patent. 

II. 

On appeal, Teva argues that the district court erred in holding that Abbott had 

demonstrated that Teva’s invalidity defense to claims 2, 4 and 6 of the ’718 patent 

lacked substantial merit. Teva also argues that the district court erred in finding that 

Abbott had established that it would suffer irreparable harm if Teva were not enjoined. 

As a result of those two errors, Teva alleges that the district court abused its discretion 

in granting Abbott’s motion for preliminary injunction. 

In response, Abbott contends that, as to claims 2, 4, and 6 of the ’718 patent, it 

made a clear showing of likelihood of success on the merits and it is entitled to the 

presumption that it would suffer irreparable harm absent the preliminary injunction. 

Furthermore, Abbott argues that the preliminary injunction ruling could be affirmed on 

the alternate grounds that Teva failed to raise a substantial challenge to the validity of 

claim 2 of the ’616 patent. 

The grant or denial of a preliminary injunction under 35 U.S.C. § 283 is within the 

sound discretion of the district court. Amazon.com, Inc. v. Barnesandnoble.com, 239 

F.3d 1343, 1350 (Fed. Cir. 2001). As the Supreme Court recently held on the closely 

related topic of permanent injunctions, “[t]he decision to grant or deny permanent 

injunctive relief is an act of equitable discretion by the district court, reviewable on 

appeal for abuse of discretion.” eBay, Inc. v. MercExchange, L.L.C., 126 S. Ct. 1837, 

05-1433 5
1839 (2006). “These familiar principles apply with equal force to disputes arising under 

the Patent Act. . . . . [T]he Patent Act expressly provides that injunctions ‘may’ issue ‘in 

accordance with the principles of equity.’” Id. (quoting 35 U.S.C. § 283). As the moving 

party, Abbott had to establish its right to a preliminary injunction in light of four factors: 

(1) the movant has some likelihood of success on the merits of the 

underlying litigation; (2) immediate irreparable harm will result if the relief 

is not granted; (3) the balance of hardships to the parties weighs in the 

movant’s favor; and (4) the public interest is best served by granting the 

injunctive relief. 

Polymer Techs., Inc. v. Bridwell, 103 F.3d 970, 973 (Fed. Cir. 1996). 

An abuse of discretion in granting or denying a preliminary injunction may be 

found “by showing 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.” Id. (quoting Novo Nordisk of N. Am., Inc. v. Genentech, Inc., 77 F.3d 

1364, 1367 (Fed.Cir.1996)). We now turn to the factors relevant to a motion for a 

preliminary injunction. 

III. 

As to Abbott’s likelihood of success on the merits, “Teva does not dispute that its 

generic clarithromycin extended release formulation infringes Abbott’s ’718 and ’616 

patents. Teva asserts that those patents . . . are invalid for obviousness under 35 

U.S.C. § 103 (2004).” Abbott Labs., slip op. at 3. As a result, “if [the defendant] raises 

a substantial question concerning . . . validity, i.e. . . . [an] invalidity defense that the 

patentee cannot prove ‘lacks substantial merit’” then the patentee has not established a 

05-1433 6
likelihood of success on the merits.2

 Amazon.com, 239 F.3d at 1350-51 (citing 

Genentech, Inc. v. Novo Nordisk, A/S, 108 F.3d 1361, 1364 (Fed. Cir. 1997)). 

Furthermore, as this case involves multiple patent claims, “the patentee must 

demonstrate that . . . at least one of [the] allegedly infringed claims will . . . likely 

withstand the validity challenges presented by the accused infringer.” Id. As to the

burden regarding invalidity allegations, “[v]alidity challenges during preliminary 

injunction proceedings can be successful, that is, they may raise substantial questions 

of invalidity, on evidence that would not suffice to support a judgment of invalidity at 

trial.” Id. at 1358 (citing Helifix, 208 F.3d at 1352). As this court has stated 

In resisting a preliminary injunction, however, one need not make out a 

case of actual invalidity. Vulnerability is the issue at the preliminary 

injunction stage, while validity is the issue at trial. The showing of a 

substantial question as to invalidity thus requires less proof than the clear 

and convincing showing necessary to establish invalidity itself. 

 2 The dissent appears to take issue with the conclusion that a likelihood of 

success on the merits is not found where there exists a substantial question of validity. 

The majority opinion, however, is duty bound by our precedent which states exactly this 

proposition. In Genentech, Inc. v. Novo Nordisk, A/S, this court stated that 

In order to demonstrate that it has a likelihood of success, Genentech 

must show that, in light of the presumptions and burdens that will inhere at 

trial on the merits, (1) it will likely prove that Novo infringes the ’199 patent 

and (2) its infringement claim will likely withstand Novo’s challenges to the 

validity and enforceability of the ’199 patent. In other words, if Novo raises 

a ‘substantial question’ concerning validity, enforceability, or infringement 

(i.e., asserts a defense that Genentech cannot show ‘lacks substantial 

merit’) the preliminary injunction should not issue. More specifically, with 

regard to Novo’s validity defenses, the question on appeal is whether the 

[defenses have] substantial merit . . . . 

108 F.3d 1361, 1364 (Fed. Cir. 1997); see also Tate Access Floors, Inc. v. Interface 

Architectural Res., Inc., 279 F.3d 1357, 1365 (Fed. Cir. 2002), Purdue Pharma L.P. v. 

Boehringer Ingelheim GMBH, 237 F.3d 1359, 1363 (Fed. Cir. 2001), Helifix Ltd. v. BlokLok, Ltd., 208 F.3d 1339, 1351 (Fed. Cir. 2000). 

05-1433 7
Id. at 1359. “When moving for the extraordinary relief of a preliminary injunction, a 

patentee need not establish the validity of a patent beyond question. The patentee 

must, however, present a clear case supporting the validity of the patent in suit.” Id.

(citations omitted). 

Turning to Teva’s invalidity contentions based on obviousness, “‘the first step is 

to determine the meaning and scope of each claim in suit.’” Id. (quoting Lemelson v. 

Gen. Mills, Inc., 968 F.2d 1202, 1206 (Fed. Cir. 1992)). “Only when a claim is properly 

understood can a determination be made . . . whether the prior art . . . renders obvious 

the claimed invention.” Id. We have stated that “[q]uite apart from the written 

description and the prosecution history, the claims themselves provide substantial 

guidance as to the meaning of particular claim terms.” Phillips v. AWH Corp., 415 F.3d 

1303, 1314 (Fed. Cir. 2005). “First, we look to the words of the claims themselves, both 

asserted and nonasserted, to define the scope of the patented invention.” Vitronics 

Corp. v. Conceptronic, Inc., 90 F.3d 1576, 1582 (Fed. Cir. 1996). Where claim terms 

are ambiguous or disputed, then we turn to the specification as “the specification ‘is 

always highly relevant to the claim construction analysis. Usually, it is dispositive; it is 

the single best guide to the meaning of a disputed term.’’’ Phillips, 415 F.3d at 1315 

(quoting Vitronics, 90 F.3d at 1582). 

Once the scope of the claims are determined, the actual obviousness 

determination under 35 U.S.C. § 103 begins. Recently this court re-iterated the proper 

standards for making determinations under § 103. In re Kahn, 441 F.3d 977 (Fed. Cir. 

2006). First, the court 

determines the scope and content of the prior art, and ascertains the 

differences between the prior art and the claims at issue, and resolves the 

05-1433 8
level of ordinary skill in the pertinent art. Against this background, the 

[court] determines whether the subject matter would have been obvious to 

a person of ordinary skill in the art at the time of the asserted invention. 

Id. at 985 (citing Dann v. Johnston, 425 U.S. 219, 226 (1976) and Graham v. John 

Deere Co., 383 U.S. 1, 13-14 (1966)). In making this determination, we noted in Kahn

that “[m]ost inventions arise from a combination of old elements and each element may 

often be found in the prior art.” Id. at 986. The prior art that is considered is drawn from 

references “either in the field of the applicant’s endeavor or is reasonably pertinent to 

the problem with which the inventor was concerned.” Id. at 987. 

However, mere identification in the prior art of each element is insufficient 

to defeat the patentability of the combined subject matter as a whole. 

Rather, 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. at 986. 

This ‘motivation-suggestion-teaching’ test asks not merely what the 

references disclose, but whether a person of ordinary skill in the art, 

possessed with the understandings and knowledge reflected in the prior 

art, and motivated by the general problem facing the inventor, would have 

been led to make the combination recited in the claims. 

Id. at 988. 

In analyzing Teva’s obviousness contentions as to claims 2, 4, and 6 of the ’718 

patent and Abbott’s alternative grounds for affirming the preliminary injunction under 

claim 2 of ’616 patent, we separate the analysis into two parts. Claim 2 and 4 of the 

’718 patent are closely related and are addressed first. Claim 6 of the ’718 patent and 

claim 2 of the ’616 patent are dealt with next. For each pair of claims, we construe the 

claims and we determine if the allegations raise substantial questions of obviousness. 

05-1433 9
A. 

We begin by examining claim 2 and 4 of the ’718 patent and the district court’s 

analysis regarding these claims. Claim 2 of the ’718 patent claims3

a pharmaceutical composition for extended release of an erythromycin 

derivative in the gastrointestinal environment, comprising 

an erythromycin derivative and 

from about 5 to about 50% by weight of a pharmaceutically acceptable 

polymer, wherein the polymer is a hydrophilic water-soluble polymer, 

so that when ingested orally, the composition induces statistically 

significantly lower mean fluctuation index in the plasma than an immediate 

release composition of the erythromycin derivative while maintaining 

bioavailability substantially equivalent to that of the immediate release 

composition of the erythromycin derivative. 

’718 patent, col. 11, ll. 28-40. In short, claim 2 has three basic elements. First, the 

extended release composition includes an erythromycin derivative. Second, it includes 

a polymer. Third, the claim includes specific pharmacokinetic parameters that the 

erythromycin derivative and polymer composition must meet. 

Similarly, claim 4 claims 

a pharmaceutical composition for extended release of an erythromycin 

derivative in the gastrointestinal environment, comprising 

an erythromycin derivative and 

from about 5 to about 50% by weight of a pharmaceutically acceptable 

polymer, 

so that upon oral ingestion, maximum peak concentrations of the 

erythromycin derivative are lower than those produced by an immediate 

release pharmaceutical composition, and area under the concentrationtime curve and the minimum plasma concentration are substantially 

equivalent to that of the immediate release pharmaceutical composition. 

 3 Claim 2 of the ’718 patent depends from independent claim 1. The 

language recited for claim 2 includes the combined limitations of claim 1 and claim 2. 

05-1433 10
’718 patent, col. 11, ll. 48-58. As can be seen, claim 4 also has three basic elements: 

the erythromycin derivative, the polymer, and specific (but different from claim 2) 

pharmacokinetic parameters. 

From the specification, the district court defined erythromycin derivative in both 

claims as meaning “‘erythromycin having no substituent groups, or having conventional 

substituent groups, in organic synthesis, in place of a hydrogen atom of the hydroxy 

groups and/or a methyl group of the 3’-dimethylamino group, which is prepared 

according to the conventional manner.’” Abbott Labs., slip op. at 10 (quoting ’718 

patent, col. 3, ll. 34-39). Notably, this definition of erythromycin derivative includes 

clarithromycin but excludes azithromycin, a related macrolide antibiotic sold by Pfizer as 

the drug Zithromax. 

Then, construing “pharmaceutically acceptable polymer,” the district court again 

properly turned to the ’718 patent specification. The specification describes this as “a 

water-soluble hydrophilic polymer selected from the group consisting of 

polyvinylpyrrolidine, hydroxypropyl cellulose, hydroxypropylmethyl cellulose, methyl 

cellulose, vinyl acetate/crotonic acid copolymers, methacrylic acids copolymers, maleic 

anhydride/methyl vinyl ether copolymers and derivatives and mixtures thereof.” Id.

(quoting ’718 patent, col. 3, l. 65 – col. 4, l. 4). Furthermore, the specification describes 

the “‘more preferabl[e]’” polymer as hydroxypropylmethyl cellulose (“HPMC”). Id.

(quoting ’718 patent, col. 4, l. 7). 

The district court also construed the more technical limitations in the claims. In 

claim 4 the pharmacokinetic limitations require that 

upon oral ingestion, maximum peak concentrations of the erythromycin 

derivative are lower than those produced by an immediate release 

05-1433 11
pharmaceutical composition, and area under the concentration-time curve 

and the minimum plasma concentration are substantially equivalent to that 

of the immediate release pharmaceutical composition. 

The district court elaborated on this language by stating that 

[t]his means that the concentration-time curve representing the 

concentration of drug in blood plasma will be flatter and lower for the 

extended release formulation than for the immediate release formulation, 

but will have an area under the curve (“AUC”) that is substantially 

equivalent to that of its immediate release corollary. At the same time, the 

minimum plasma concentration for the extended release formulation will 

be substantially the same as that of the immediate release formulation, 

meaning that the drug will be present in the blood at the same minimum 

level at all times for both the immediate release and extended release 

formulations. 

Id. 

The district court did not address the pharmacokinetic limitations of claim 2 

explicitly. Below, in our analysis, we turn to the specification to aid in defining the 

pharmacokinetic parameters of claim 2. 

In making its invalidity contentions, Teva pointed to a number of prior art 

references. These included published Patent Cooperation Treaty application WO 

95/30422 (“the ’422 publication”). It pertained to controlled-release dosage forms of 

azithromycin with HPMC that, among other things, was meant to address the GI side 

effects of azithromycin. 

Teva also pointed to Abbott’s own U.S. Patent No. 5,705,190 (“’190 patent”) 

which disclosed a controlled release pharmaceutical formulation of clarithromycin 

combined with a water soluble alginate salt. Furthermore, Teva also cited a number of 

other prior art references including textbooks and government and trade publications 

that discussed controlled release pharmaceuticals. The district court characterized 

these more general sources as “sources in the prior art discussing extended release 

05-1433 12
formulations and seeking ways to develop formulations that achieved desirable 

pharmacokinetic goals.” Id.

Considering its tentative claim construction and after reviewing these prior art 

references, the district court determined that 

Teva has failed to raise a substantial question as to the validity of Abbott’s 

claim 2 and 4. The prior art cited by Teva discloses discrete portions of 

the asserted claims, but Teva fails to demonstrate that this would be 

sufficient to give a person of ordinary skill in the art a reasonable 

expectation of success. Teva’s prior art references reveal that using 

HPMC was a logical line of inquiry but the dissimilarities between the 

drugs with which HPMC had been successfully combined and 

clarithromycin defeat Teva’s claim of obviousness. . . . Abbott has 

provided ample evidence that its invention was not obvious and that there 

were many other extended release formulations known in the prior art. 

Abbott Labs., slip op. at 17-18. 

1. 

On appeal, we begin, as did the district court, with the claims. We agree with the 

district court’s preliminary claim construction as to “erythromycin derivative” and 

“pharmaceutically acceptable polymer” in both claims 2 and 4. Furthermore, we agree 

with the district court’s elaboration on the pharmacokinetic parameters of claim 4. In 

short, the parameters of claim 4 require three things: 

[1] maximum peak concentrations of the erythromycin derivative are lower 

than those produced by an immediate release pharmaceutical 

composition, [2] area under the concentration-time curve are substantially 

equivalent to that of the immediate release pharmaceutical composition 

and, [3] the minimum plasma concentration are substantially equivalent to 

that of the immediate release pharmaceutical composition. 

’718 patent, col. 11, ll. 48-58. In order to more fully understand these specific 

parameters, we turn to the specification. It defines a number of the relevant 

pharmacokinetic parameters used in these claims. The specification defines the 

“maximum plasma concentration of the erythromycin derivative, produced by the 

05-1433 13
ingestion of the composition of the invention or the IR comparator” as CMax. ’718 patent, 

col. 3, ll. 13-15. Likewise, the minimum plasma concentration is defined as CMin. ’718 

patent, col. 3, ll. 15-19. The specification defines the area under the curve, AUC, “as 

the area under the plasma concentration-time curve, as calculated by the trapezoidal 

rule over the complete 24-hour interval for all the formulations.” ’718 patent, col. 3, ll. 

26-29. From these definitions given in the specification, we can describe the three 

pharmacokinetic limitations of claim 4 as CMax_ER< CMax_IR , AUCER = AUCIR , and CMin_ER 

= CMin_IR.

4

As to claim 2, the district court did not explicitly discuss that claim’s 

pharmacokinetic parameters. Nonetheless, just as with claim 4, the parameters in claim 

2 are defined in the specification. Claim 2 requires that 

the composition [1] induces statistically significantly lower mean fluctuation 

index in the plasma than an immediate release composition of the 

erythromycin derivative while [2] maintaining bioavailability substantially 

equivalent to that of the immediate release composition of the 

erythromycin derivative. 

The specification defines the “degree of fluctuation” or DFL as Av

Max Min

C

C C

DFL − =

, ’718 

patent, col. 3, l. 33. CAv is the average concentration of the drug over a twenty-four hour 

interval, ’718 patent, col. 3, ll. 19-22, and generally is defined as CAv = AUC/τ where τ is 

twenty-four hours. See Shargel & Yu, Applied Biopharmaceutics and Pharmacokinetics

252 (3d ed. 1993). The ’718 patent specification defines “bioavailability” as the logtransformed AUC. ’718 patent, col. 7, l. 17. Based on this logarithm-based definition, it 

 4 There is little in the patent itself that establishes the differences (if any) 

between parameters that are simply “lower” rather than “statistically significantly lower” 

and the specification does not explicitly define when two parameters are “substantially 

equivalent.” For purposes of this preliminary injunction, we do not reach these more 

nuanced issues in claim construction. 

05-1433 14
follows that, at a minimum, where AUCER = AUCIR then the two compositions would 

have substantially equivalent bioavailability. Thus, sufficient conditions for satisfying 

claim 2’s pharmacokinetic parameters are that: DFLER < DFLIR and AUCER = AUCIR. 

2. 

We now turn to the relevant prior art and begin by focusing on the invalidty 

allegations surrounding claim 4. As described above, the prior art includes the ’190 

patent owned by Abbott. The patent, inter alia, describes and claims compositions of 

clarithromycin in an alginate matrix. Abbott itself describes that “the formulations are 

administered once a day and are directed towards increasing the bioavailability of the 

active ingredient so that it is bioequivalent with the current immediate release, twice aday compositions.” ’190 patent, col. 1, ll. 43-47. Several disclosures in this patent merit 

attention. Claim 4 of the ’190 patent claims “a controlled release, solid pharmaceutical 

composition . . . comprising: a therapeutically effective amount of a macrolide . . . [and] 

a water-soluble alginate salt . . . .” Furthermore, claim 5 of the ’190 patent claims “[t]he 

composition of claim 4 wherein the macrolide is clarithromycin.” Thus, the ’190 patent 

discloses an extended release formulation of clarithromycin wherein the polymer used is 

alginate as opposed to the polymers like HPMC claimed in the ’718 patent. 

The ’190 patent also discloses particular pharmacokinetic parameters for its 

controlled release clarithromycin and alginate compositions. For example, as pointed 

out by Teva, a side-by-side comparison of Formula C of the ’190 patent with an IR 

formulation shows that Formula C exhibited a lower CMax (2.00 μg/mL) than the 

immediate release formulation (2.28 μg/mL) and substantially equivalent AUC (28.69 

 

05-1433 15
ranging from 24.61 to 32.74 μg h/mL vs. 32.16 ranging from 25.66 to 42.70 μ gh/mL ) 

and substantially equivalent CMin (0.66 ranging from 0.37 to 0.91 μg/mL vs. 0.72 ranging 

from .54 to 1.05 μg/mL). ’190 patent, col. 7, table 2. Thus, Teva makes substantial 

arguments that the ’190 patent discloses a clarithromycin composition with alginate (as 

opposed to a polymer like HPMC) that arguably has the pharmacokinetic parameters 

required in claim 4 of the ’718 patent. 

Of the claim limitations in claim 4 of the ’718 patent, the ’190 patent does not 

disclose the claimed polymers of the ’718 patent. The ’190 patent only discloses the 

use of alginate in making controlled release formulations. Other prior art, though, does 

disclose extended release formulations with pharmaceutically acceptable polymers like 

HPMC. For example, the ’422 publication filed by Pfizer Inc., discloses controlledrelease dosage forms of azithromycin. In particular, the application disclosed controlled 

release formulations created from combining azithromycin with HPMC. Abbott Labs., 

slip op. at 14. 

On appeal, Teva argues that, based on the ’422 publication, a person of ordinary 

skill in the art would replace the alginate of the ’190 patent with HPMC because the ’422 

publication disclosed using HPMC with azithromycin, a compound related to 

clarithromycin. In response, Abbott points out that most inventions arise from a 

combination of old elements and that “identification in the prior art of each individual part 

claimed is insufficient to defeat patentability of the whole claimed invention.” Abbott 

Labs., slip op. at 15 (quoting In re Kotzab, 217 F.3d 1365, 1370 (Fed. Cir. 2000)). 

As mentioned above, there must be some motivation, suggestion, or teaching of 

the desirability of making the specific compound. Abbott argues that such a motivation 

05-1433 16
is lacking here because the compounds azithromycin and clarithromycin are so different 

that the ’422 publication would not reasonably motivate a person of skill in the art to 

interchange the components of the formulations in the ’422 publication with those of the 

’190 patent with a reasonable expectation of success. The district court agreed with 

Abbott and found that because of the chemical and metabolic differences between 

azithromycin and clarithromycin, “a person of ordinary skill in the art would not have had 

a reasonable expectation that the azithromycin formulation in the ’422 publication . . . 

would lead to the features claimed in the ’718 patent.” Id. at 16. It is in this conclusion 

that the district court erred. 

The district court concluded that Teva had not raised a substantial question that 

a person of ordinary skill in the art would have had a reasonable expectation of success 

in making the claimed invention. The prior art, however, especially Abbott’s own ’190 

patent, contradicts that conclusion. As argued by Teva, another claim from the ’190 

patent merits close attention. Not only does the ’190 patent claim compositions with 

clarithromycin, but claim 14 of the ’190 patent claims “[t]he composition of claim 4, 

wherein the macrolide is selected from the group consisting of erythromycin, 

dirithromycin, azithromycin, roxithromycin, and ABT-229.” This claim is relevant 

because it describes Abbott’s own view of the ordinary skill in the art at the time it filed 

the application that led to the ’190 patent and it does so not by what the ’190 patent 

discloses but by what it does not disclose. Claim 4 and 14 of the ’190 patent cover 

compositions that include azithromycin or clarithromycin. Despite these claims to varied 

compositions, the specification only explicitly describes compositions made from 

clarithromycin. We presume that Abbott filed and prosecuted the ’190 patent 

05-1433 17
representing that claim 14 of the ’190 patent satisfies the written description and 

enablement requirements of 35 U.S.C. § 112. See Amgen Inc. v. Hoechst Marion 

Roussel, Inc., 314 F.3d 1313 (Fed. Cir. 2003) (“[W]e hold a presumption arises that both 

the claimed and unclaimed disclosures in a prior art patent are enabled.”). Because the 

’190 patent explicitly discloses only clarithromycin controlled release compositions, yet 

claims azithromycin compositions, we conclude that Abbott has represented to the U.S. 

Patent and Trademark Office (“PTO”) that the differences between clarithromycin and 

azithromycin were such that azithromycin could be substituted into a controlled release 

clarithromycin composition by a person of ordinary skill in the art without undue 

experimentation. See Invitrogen Corp. v. Clontech Labs., Inc., 429 F.3d 1052, 1070-71 

(Fed. Cir. 2005) (“Section 112 requires that the patent specification enable those skilled 

in the art to make and use the full scope of the claimed invention without undue 

experimentation . . . . The scope of enablement, in turn, is that which is disclosed in the 

specification plus the scope of what would be known to one of ordinary skill in the art 

without undue experimentation.”). As a result, based on Abbott’s own ’190 patent, there 

exists a substantial argument that a person of ordinary skill in the art would be 

motivated to combine the ’422 publication, namely the use of HPMC in extended 

release macrolide compositions, with the ’190 patent with a reasonable expectation of 

success. 

Furthermore, the district court also erred by focusing on the drugs’ chemical 

dissimilarities, while not properly accounting for their similarities. It appears to have 

focused on the presence of differences per se, rather than on those differences that 

would be relevant vel non to one of ordinary skill in the art. For example, the court 

05-1433 18
appears to have been influenced by Abbott’s expert, Dr. Banker, who pointed out that 

the half-life of azithromycin is longer than that of clarithromycin. Dr. Banker also noted 

that clarithromycin exhibits an extensive “first-pass” metabolism to an active metabolite, 

whereas azithromycin does not. However, the court appears to have inexplicably 

discounted the testimony of Dr. Lee. As Dr. Lee noted, because the drug is transformed 

into an active metabolite, “a person skilled in the art would have expected that 

clarithromycin would work even better than azithromycin in an extended release 

formulation.” Addressing the drugs’ differences in half-life and metabolism, Dr. Lee 

concluded that “these characteristics further support the expectation that a person of 

ordinary skill in the art would have motivation and a reasonable expectation of success 

in making a successful ER formulation of clarithromycin . . . .” (emphasis added).

In light of the record, Teva has raised a substantial question that claim 4 is 

vulnerable to allegations of invalidity. The ’190 patent itself demonstrates that Abbott 

has represented to the PTO and the public in general that a person of ordinary skill in 

the art can expect to successfully substitute azithromycin into a clarithromycin controlled 

release composition without undue experimentation. 

Claim 2 presents a slightly different analysis. The prior art and the obviousness 

discussion from claim 4 could be applied directly to claim 2 but for the differences in 

pharmacokinetic limitations. Upon inspection, the ’422 publication and the ’190 patent 

disclose compositions satisfying the pharmacokinetic limitations of claim 2 and therefore 

the obviousness arguments from above do apply and provide a substantial argument as 

to the invalidity of claim 2. As discussed above, where two compositions have similar 

AUCs, these compositions have similar bioavailability. The ’190 patent discloses 

05-1433 19
compositions with similar AUC’s and therefore there exists a substantial argument that it 

discloses compositions with substantially equivalent bioavailability. ’190 patent, col. 7, 

table 2. Thus, the ’190 patent discloses compositions that satisfy the second of the 

pharmacokinetic limitations of claim 2. Furthermore, although the ’190 patent does not 

explicitly disclose compositions with a lower fluctuation index, the ’190 patent, 

nonetheless, does so implicitly. By comparing the disclosed pharmacokinetic 

parameters from the ’190 patent, a substantial argument exists that the ’190 patent also 

discloses compositions satisfying DFLER < DFLIR. As discussed above, the ’190 patent 

discloses pharmacokinetic parameters that satisfy claim 4. In other words, the ’190 

patent discloses a composition that satisfies: CMax_ER< CMax_IR , AUCER = AUCIR , and 

CMin_ER = CMin_IR. By examining the definitions given in the specification, we conclude 

that the disclosed composition from the ’190 patent also implicitly satisfies the condition 

from claim 2 that DFLER < DFLIR. By subtracting claim 4’s third condition from the first, 

one can infer that the composition from the ’190 patent also satisfies 

. This inequality, with the definition of the fluctuation index, 

and with the second limitation from claim 4, establishes that: 

CMaxER −CMinER < CMaxIR −CMinIR

IR

AvIR

MaxIR MinIR

IR

MaxIR MinIR

ER

MaxER MinER

AvER

MaxER MinER

ER DFL

C

C C

AUC

C C

AUC

C C

C

C C

DFL = − = − < − = − = /τ /τ . 

In other words, because the ’190 patent disclosed a composition satisfying the 

pharmacokinetic limitations of claim 4, the ’190 patent also disclosed compositions that 

satisfy DFLER < DFLIR and are substantially bioequivalent.5

 Thus, the obviousness 

 5 As mentioned above, though the inequality follows strictly from satisfying 

the conditions of claim 4, this does not necessarily lead to the conclusion that the 

fluctuation index of the extended release formulation is “statistically significantly lower” 

05-1433 20
arguments relating to the ’190 patent and the ’422 publication made above for claim 4 

can be applied in similar fashion to claim 2. As a result, Teva has also raised 

substantial questions as to the validity of claim 2. 

B.

We now turn to claim 6 of the ’718 patent and claim 2 of ’616 patent.6

 In its

analysis, the district began by looking to the claims. Claim 2 of the ’616 patent sets 

forth 

a method of reducing gastrointestinal adverse side effects comprising 

administering an effective amount of an extended release pharmaceutical 

composition comprising an erythromycin derivative and a pharmaceutically 

acceptable polymer, wherein the erythromycin derivative is clarithromycin. 

’616 patent, col. 12, ll. 39-46. For these claims, “erythromycin derivative” and 

“pharmaceutically acceptable polymer” are construed as they are construed in claims 2 

and 4 of the ’718 patent discussed above. As to claim 2, the district court relied on the 

plain meaning of “reducing gastrointestinal adverse side effects.” 

At the district court, Teva argued that 

[w]ell before the invention of the patent, adverse gastrointestinal effects 

were widely known as side effects of both erythromycin and clarithromycin 

and, to a lesser degree, azithromycin. In addition, persons skilled in the art 

knew that one way to reduce these gastrointestinal effects was to 

 

than the immediate release. But nonetheless, the result derived here is enough to show 

that Teva has produced substantial argument as to the invalidity of claim 2. This is true 

despite the example given in the ’718 patent analyzing Formula A from the ’190 patent 

for its pharmacokinetic parameters, ’718 patent, col. 10, ll. 62-67, most notably, 

because Formula C not Formula A from the ’190 patent appears to satisfy the 

pharmacokinetic limitations of claims 2 and 4 of the ’718 patent. 

6 The district court concluded that Teva had made a substantial argument 

as to the invalidity of claim 2 of the ’616 patent. In this appeal, Abbott argues that claim 

2 of the ’616 could form an alternative basis for upholding the preliminary injunction and 

therefore we also review the parties’ arguments as to the validity of claim 2. 

05-1433 21
formulate the drug in a polymer matrix, e.g., an extended release 

formulation. The GI side effects of clarithromycin were known to be 

dependent on the drug concentration in the blood. Moreover, the ’422 

[publication] for extended release azithromycin disclosed that extended 

release compositions of that closely-related compound reduced 

gastrointestinal side effects. 

Abbott Labs., slip op. at 21. In contrast, Abbott argued, inter alia, that “the 

gastrointestinal side effects of different active pharmaceutical agents are so distinct that 

the pharmacokinetic properties of a formulation with one drug are not predictive of a 

similar formulation with another drug.” Id.

After reviewing the prior art, the district court concluded that 

Abbott has failed to meet its burden of demonstrating that Teva’s 

opposition lacks substantial merit. This court finds that the prior art, 

specifically the discussions in industry treatises and medical journals of 

formulations that reduced GI irritation, the teachings of the ’422 

[publication], and the reference material in the Physicians’ Desk 

Reference regarding side effects, would lead a person of ordinary skill in 

the art to expect that an extended release formulation of clarithromycin 

would reduce adverse GI side effects. 

Id. at 22. 

Claim 6 of the ’718 patent claims 

an extended release pharmaceutical composition comprising an 

erythromycin derivative and a pharmaceutically acceptable polymer, the 

composition having an improved taste profile as compared to the 

immediate release formulation. 

’718 patent, col. 12, ll. 23-27. As to claim 6, the district court specifically construed the 

term “taste profile” noting that the specification of the ’718 patent describes “taste 

profile” in parentheses immediately following the words “taste perversion.” ’718 patent, 

col. 9, ll. 23-24. The specification defines “taste perversion” as “the perception of a 

bitter metallic taste normally associated with the erythromycin derivatives, particularly, 

with clarithromycin.” ’718 patent, col. 3, ll. 53-55. Based on this usage in the 

05-1433 22
specification, the district court concluded that “taste perversion” and “taste profile” are 

“used synonymously.” Abbott Labs., slip op. at 19. 

At the district court, Teva argued that “[i]t was known that clarithromycin caused 

taste perversion and this created a motivation for formulators to try to create an 

extended release formulation that would have a[n] improved taste profile. As support, 

Teva cited a 1993 article written by Abbott researchers, discussing the 

pharmacokinetics of single- and multiple-dose clarithromycin.” Id. at 19 (citations 

omitted). Furthermore, Teva also relied on Pfizer’s ’422 publication which, as discussed 

above, disclosed extended release formulations for amelioration of other macrolide 

related side effects. Abbott argued that only its own study by its researchers mentioned 

taste perversion. The other references, like the ’422 publication, either describe other 

non-taste related side effects or they describe “taste masking” rather than “taste 

perversion.” Id. Furthermore, as to its one study, Abbott argued that the mere fact that 

taste perversion is mentioned does not make claim 6 obvious and, additionally, that 

Teva had not even shown evidence that taste perversion is dose dependent. 

After weighing the prior art, the district court 

agree[d] with Abbott that Teva has not met its burden of raising a 

substantial question as to the validity of claim 6. Teva relies primarily on 

only one study, cited apparently in only one article, that mentions taste 

perversion as a known side effect of clarithromycin, and even then, in only 

one of thirty-eight research subjects. This court finds that Teva has failed 

to provide sufficient evidence to demonstrate that improved taste profile as 

a result of an extended release formulation of clarithromycin would have 

been obvious to an ordinary person skilled in the art. 

Id. at 20. 

05-1433 23
The district court concluded that Teva failed to raise a substantial question as to 

claim 6 of the ’718 patent but the district court found Teva had raised a substantial 

question as to the validity of claim 2 of the ’616 patent. 

1. 

The district court properly construed the claims for the purposes of the 

preliminary injunction. “Erythromycin derivative” and “pharmaceutically acceptable 

polymer” are construed as above. Furthermore, for claim 2 of the ’616 patent, reducing 

gastrointestinal side effects is given its plain meaning while for claim 6 of the ’718 

patent, “taste profile” is read as synonymous with “taste perversion.” 

2. 

We now turn to the obviousness contentions based on the above construction of 

claim 2 and 6. Even though claim 2 is a method claim and claim 6 is a composition, 

they both deal with ER compositions of erythromycin derivatives combined with 

pharmaceutically acceptable polymers that can improve adverse side effects compared 

to the IR compositions. As a result, the obviousness analysis is quite similar for both 

claims. Claim 2 addresses reducing adverse GI side effects while claim 6 addresses 

improving the taste profile. 

These two claims have three major components. They require an erythromycin 

derivative, a polymer, and they each recite improvement of a side effect (taste 

perversion for claim 6 of the ’718 patent and GI side effects for claim 2 of the ’616 

patent). Following the discussion above of claim 2 and 4 of the ’718 patent, there are 

substantial arguments that an extended release formulation with an erythromycin 

05-1433 24
derivative and an acceptable polymer would have been obvious in light of the prior art.7

 

The validity of claim 2 and claim 6 likely hinges on the extra limitations regarding the 

claimed improved side-effects. In its brief on appeal, Abbott contends that “[t]he 

inventions of the patents in suit decrease the incidence and severity of two primary side 

effects of clarithromycin: taste perversion and gastrointestinal distress. . . . [T]hese 

discoveries form the basis of claim 6 of the ’718 patent and claim 2 of the ’616 patent 

respectively.” As to such claims, this court has stated that “when unexpected results 

are used as evidence of nonobviousness, the results must be shown to be unexpected 

compared with the closest prior art.” In re Baxter Travenol Labs., 952 F.2d 388, 392 

(Fed. Cir. 1991) (citing In re De Blauwe, 736 F.2d 699, 705 (Fed. Cir. 1984)). 

The prior art and Abbott’s own statements in its briefs indicate that the reduction 

of systemic side effects would not be surprising and would not be unexpected. This, 

therefore, raises a substantial question as to the validity of the claims. First, as to the 

GI side-effects, the district court found that the “GI side effects of clarithromycin were 

known to be dependent on the drug concentration in the blood.” Abbott Labs., slip op. 

at 21. Furthermore, the district court found that Abbott contended that “an extended 

release formulation would reduce the maximum blood plasma concentration of the 

drug.” Id. Thus, the resulting reduction in GI side-effects cannot be said to be 

unexpected and the district court correctly found that Teva raised a substantial question 

as to the invalidity of claim 2 of the ’616 patent. 

 7 As opposed to claim 2 and 4 of the ’718 patent, claim 6 of the ’718 and 

claim 2 of the ’616 do not limit their claimed extended release formulations with any 

specific pharmacokinetic parameters. 

05-1433 25
Second, as to taste perversion, Teva points to a number of prior art references 

including a study conducted by Abbott described in S.-y. Chu et al., Single- and 

Multiple-dose Pharmacokinetics of Clarithromycin, a New Macrolide Antimicrobial, 33 J. 

Clin. Pharmacol. 719-26 (1993). The article describes a study of single and multiple 

dose trials of clarithromycin and it reported the side effects encountered by participants 

including taste perversion. At the district court, Abbott argued “that Teva’s reliance on 

[this] Abbott study disclosed in the Journal of Clinical Pharmacology overstates its case. 

Only one of thirty eight subjects reported taste perversion as a side effect, and only at 

one of four different dosage levels.” Abbott Labs., slip op. at 19. The district court 

seemingly agreeing with Abbott’s view of that reference concluded that “this court 

agrees with Abbott that Teva has not met its burden of raising a substantial question as 

to the validity of claim 6. Teva relies primarily on only one study, cited apparently in only 

one article, that mentions taste perversion as a known side effect of clarithromycin, and 

even then, in only one of thirty-eight research subjects.” Abbott Labs., slip op. at 20. 

Upon examining that reference, we cannot agree with Abbott’s or the district 

court’s characterization. In the study, two groups of participants underwent differing 

treatment protocols. See Chu, supra, at 721. A group of twenty underwent both a 

single 250 mg clarithromycin protocol and a multiple 250 mg clarithromycin protocol. Id. 

From among these two 250 mg protocols, no participants reported taste perversion as a 

side-effect. Id. Another group of eighteen participants underwent both a single 500 mg 

protocol and a multiple 500 mg dose protocol. Id. From among these protocols, one 

participant in each of the 500 mg protocols reported taste perversion. Id. Thus, out of 

the four trials, neither of 250 mg protocols produced taste perversion as a side-effect 

05-1433 26
while each 500 mg trial produced one reported case of taste perversion. Therefore, 

Abbott is incorrect in stating that the study only reported taste perversion at one of four 

dosage levels. Admittedly, finding 0 out of 20 cases in neither 250 mg dosage protocols 

and 1 out of 18 cases in each 500 mg protocol does not establish that taste perversion 

is dose dependent but it does support such arguments. Furthermore, as a general 

matter, the prior art also suggests that a known advantage of a sustained-release 

formulation is “a decrease or elimination of both local and systemic side effects.” 

Charles S. L. Chiao & Joseph R. Robinson, Sustained-Released Drug Delivery 

Systems, in Remington: The Science and Practice of Pharmacy, 1660, 1662 (A.R. 

Gennaro, ed. 1995). Lastly, Abbott states that “taste perversion is different from simply 

an ‘unpleasant taste’ of the drug when first ingested. . . . Rather, it refers ‘to the 

continuing effect of the drug upon the sense of taste while the drug remains in the 

bloodstream . . . .’” In other words, taste perversion is not related to a direct, local taste 

sensation from the drug on the tongue but is rather a systemic side effect. In regard to 

systemic side effects generally, Abbott states that “side effects can be either systemic - 

in which case they correlate to overall drug levels in blood - or local - in which case they 

correlate with the levels of drug being released at the site of irritation.” From these 

statements, Abbot suggests that systemic side effects like taste perversion correlate 

with overall drug blood levels. Thus, Abbott’s own statements from its brief support the 

argument that reduction of taste perversion would not be unexpected when an extended 

release formulation lowers the concentration of the drug in the blood.8

 Based, on these 

 8 This does not mean to suggest that lowering drug concentration will lead 

inexorably to improved side effects; rather, it only suggests that such an improvement 

would not be unexpected. 

05-1433 27
references and statements, a substantial question exists that the improvement of the 

taste perversion side-effect would not be unexpected in an extended release 

formulation of clarithromycin. 

Teva has raised a substantial question as to the validity of claim 6 of the ’718 

patent and claim 2 of the ’616 patent.9

 The district court was correct in concluding that 

Teva had also raised a substantial question as to invalidity of claim 2 of the ’616 patent 

and, therefore, claim 2 cannot provide an alternative grounds for affirming the 

preliminary injunction. Furthermore, as discussed above, Teva has raised a substantial 

question as to the validity of claims 2 and 4 of the ’718 patent. As a result it has raised 

a substantial question of validity with each of the asserted claims but as in 

Amazon.com, our decision today in no way resolves the ultimate question of invalidity. 

Nonetheless, for the purposes of the preliminary injunction Abbott as the moving party 

has not established a likelihood of success on the merits. 

IV. 

Turning now to the other factors in a motion for preliminary injunction, the district 

court concluded that Abbott established irreparable harm. See eBay, Inc., 126 S. Ct. at 

1839 (“According to well-established principles of equity, a plaintiff seeking a permanent 

injunction must satisfy a four-factor test before a court may grant such relief. . . . These 

familiar principles apply with equal force to disputes arising under the Patent Act.”). The 

district court presumed Abbott would suffer irreparable harm absent the injunction 

 9 Other arguments as to obviousness may also have merit such as 

arguments relating to inherency. See, e.g., In re Wiseman, 596 F.2d 1019 (CCPA 

1979). But as the arguments relating to unexpected results demonstrate the 

vulnerability of the claims to invalidity, we do not reach these other, related obviousness 

arguments. 

05-1433 28
because of its conclusion regarding likelihood of success on the merits. Furthermore, 

and in addition to the presumption, the district court considered Abbott’s economic 

consequences of denying the injunction and it concluded that “entry of the generic 

extended release formulation competitor will likely crush the market.” Abbott Labs., slip 

op. at 27. On appeal the parties dispute whether the district court properly concluded 

that Abbott would suffer irreparable harm if the injunction were not issued. Teva argues 

that any harm that Abbott may suffer could be remedied by monetary compensation. 

Abbott responds by contending that the sharp economic consequences of open 

competition from generic drugs establish the inadequacy of monetary damages and 

irreparable harm. 

First, as noted above, we conclude that Abbott has not established a likelihood of 

success on the merits. As a result, Abbott is no longer entitled to a presumption of 

irreparable harm. See Reebok Int’l Ltd. v. J. Baker, Inc., 32 F.3d 1552, 1556 (Fed. Cir. 

1994). And as to Abbott’s economic arguments, we do not doubt that generic 

competition will impact Abbott’s sales of Biaxin XL, but that alone does not establish 

that Abbott’s harm will be irreparable. As we stated in Illinois Tool Works, Inc. v. GripPak, Inc., if this court were to accept a patentee’s “argu[ments] that, ‘apart from the 

presumption,’ its ‘potential lost sales’ alone demonstrate ‘manifest irreparable harm’, 

acceptance of that position would require a finding of irreparable harm to every 

manufacturer/patentee, regardless of circumstances.” 906 F.2d 679 (Fed. Cir. 1990). 

On the other hand, we also note that the district court found that “the parties’ models of 

how the market will react to generic competition for extended release clarithromycin 

remain highly speculative” and Teva has not proven that monetary damages will suffice. 

05-1433 29
Abbott Labs., slip op. at 27. Therefore, where a patentee has not shown a likelihood of 

success on the merits, and where the patentee has not clearly established that 

monetary damages could not suffice but the defendant has not established that 

monetary damages do suffice, we cannot say that the irreparable harm prong of the 

analysis favors either party. 

As to the third prong of the analysis, the district court stated that Teva was 

“reluctan[t] or inab[le] to quantify the hardship, if any, it will face if an injunction is 

incorrectly entered” and “there is little choice but to conclude that the balance of 

hardships favors [Abbott].” Abbott Labs., slip op. at 30-31. As Teva does not appeal 

this issue, we also conclude that the district court properly found that the balance of 

hardships favors Abbott. 

Lastly, as to the public interest factor, the district court determined that “[t]o the 

extent that this court has found that the patents in suit are valid, the public interest is 

best served by enforcing them.” Id., slip op. at 32. Although the public interest inquiry 

is not necessarily or always bound to the likelihood of success of the merits, in this case 

absent any other relevant concerns, we agree with the district court that the public is 

best served by enforcing patents that are likely valid and infringed. As Abbott did not 

establish a likelihood of success on the merits, we conclude that the public interest is 

best served by denying the preliminary injunction. 

V. 

First, in determining Abbott’s likelihood of success on the merits, the district court 

clearly erred in assessing the content of the prior art. The prior art supports Teva 

arguments and Teva has raised a substantial question regarding the validity of claims 2, 

05-1433 30
4, and 6 of the ’718 and claim 2 of the ’616 patent. We conclude that Abbott has not 

established a likelihood of success on the merits and this supports denying the 

injunction. Second, absent the presumption of irreparable harm and in light of the 

arguable sufficiency of monetary damages, Abbott has not established that irreparable 

harm supports the grant of the injunction. Third, as the issue was uncontested, the 

balance of hardship still supports the grant of the injunction. Fourth and lastly, as a 

substantial question of patent validity has been raised by Teva, the public interest 

benefits from a denial of the injunction. As result of these considerations, we vacate the 

preliminary injunction. 

VACATED 

05-1433 31
United States Court of Appeals for the Federal Circuit

 05-1433 

 ABBOTT LABORATORIES, 

Plaintiff-Appellee, 

 v. 

ANDRX PHARMACEUTICALS, INC., 

and ROXANE LABORATORIES, INC., 

Defendants, 

 v. 

TEVA PHARMACEUTICALS USA, INC., 

Defendant-Appellant. 

NEWMAN, Circuit Judge, dissenting. 

It has been confirmed that the remedy of injunction in patent cases is subject to the 

sound discretion of the district court, upon application of the traditional criteria by which 

injunctive relief is evaluated and applied. eBay, Inc. v. MercExchange, L.L.C., 126 S. Ct. 

1837, 1841 (2006) ("We hold only that the decision whether to grant or deny injunctive relief 

rests within the equitable discretion of the district courts, and that such discretion must be 

exercised consistent with traditional principles of equity, in patent disputes no less than in 

other cases governed by such standards.") 

These traditional principles are no less applicable when a preliminary injunction is at 

issue, particularly when the purpose is to preserve -- not to change -- the relationship of the 
05-1433 2 

litigants during the litigation. "The purpose of a preliminary injunction is to preserve the 

relative positions of the parties until a trial on the merits can be held." Univ. of Texas v. 

Camenisch, 451 U.S. 390, 395 (1981); Smith Int'l, Inc. v. Hughes Tool Co., 718 F.2d 1573, 

1578 (Fed. Cir. 1983) ("A preliminary injunction will normally issue only for the purpose of 

preserving the status quo and protecting the respective rights of the parties pending final 

disposition of the litigation.") Precedent counsels against making an important change in 

the relationship of the parties while their dispute is being litigated, while recognizing that 

there may be circumstances warranting such change, when all of the legal and equitable 

aspects relevant to a particular case are considered. See, e.g., Mikohn Gaming Corp. v. 

Acres Gaming, Inc., 165 F.3d 891, 895 (Fed. Cir. 1998) (the preliminary injunction serves to 

preserve the status quo "lest one side prevent resolution of the questions or execution of 

any judgment by altering the status quo"); Globetrotter Software, Inc. v. Elan Computer 

Group, Inc., 236 F.3d 1363, 1367 (Fed. Cir. 2001). 

The trial court's decision with respect to the discretionary grant of a preliminary 

injunction warrants significant deference, for equitable considerations weigh heavily in 

matters of change or stability pendente lite. See Deckert v. Independence Shares Corp., 

311 U.S. 282, 290 (1940) ("'It is well settled that the granting of a temporary injunction, 

pending final hearing, is within the sound discretion of the trial court; and that, upon appeal, 

an order granting such an injunction will not be disturbed unless contrary to some rule of 

equity, or the result of improvident exercise of judicial discretion.'"); Meccano, Ltd. v. John 

Wanamaker, New York, 235 U.S. 136, 141 (1920) ("The correct general doctrine is that 

whether a preliminary injunction shall be awarded rests in sound discretion of the trial 

court."). It is particularly irregular for an appellate court to reverse this discretionary 
05-1433 3 

decision and thereby to make a significant change in the relationship of the parties, while 

presenting no explanation of how the district court abused its discretion. 

Reversal of a preliminary injunction that preserves the status quo requires a clear 

showing that the district court exceeded its discretionary authority. See We Care, Inc. v. 

Ultra-Mark Int'l Corp., 930 F.2d 1567, 1570 (Fed. Cir. 1991) ("The court's determination can 

be overturned only on a showing that it abused its discretion, committed an error of law, or 

seriously misjudged the evidence.") My colleagues do not discuss the trial judge's careful 

explanations, but, upon finding that Teva has raised a "substantial question" about patent 

validity, they hold that Teva should be permitted to practice the Abbott invention before 

patent validity is decided. With all respect to my colleagues' concerns, they misapply not 

only the criteria of the preliminary injunction but also the standard of appellate review: 

First, as to patent validity, the panel majority rejects the requirement that in 

determining the likelihood that the patent will be proved invalid it is necessary to consider 

the burdens of proof that would inhere at trial. See Canon Computer Sys., Inc. v. Nu-Kote 

Int'l., Inc., 134 F.3d 1085, 1088 (Fed. Cir. 1998) ("However, a patent is presumed valid, and 

this presumption exists at every stage of the litigation. "); Genentech, Inc. v. Novo Nordisk, 

A/S, 108 F.3d 1361, 1364 (Fed. Cir. 1997) (criterion "substantial questions of validity" 

means that "in light of the presumptions and burdens that will inhere at trial on the merits" 

the attacker has "a likelihood of success" in invalidating the patent); PPG Indus., Inc. v. 

Guardian Indus., Inc., 75 F.3d 1558 (Fed. Cir. 1996) ("The ultimate question, however, is 

whether the challenger's evidence of invalidity is sufficiently persuasive that it is likely to 

overcome the presumption of patent validity.") In the case now before us the district court 

analyzed the evidence, in which technologically complex questions are presented, and 
05-1433 4 

concluded that Teva was not likely to prove the patent invalid by clear and convincing 

evidence. In contrast, the panel majority holds that if the attacker raises no more than a 

"substantial question" of invalidity, that suffices to establish the likelihood that the attacker 

will succeed on the merits. That is incorrect in law and in procedure. 

Next, even as the panel majority states its agreement with the district court's finding 

that "the balance of hardships favors Abbott," maj. op. at 30, the majority declines to weigh 

this factor in its decision. See Chrysler Motor Corp. v. Auto Body Panels of Ohio, Inc., 908 

F.2d 951 (Fed. Cir. 1990) ("Our rule regarding whether a preliminary injunction should be 

granted or denied is that the trial court should weigh and measure each of the four factors 

against the other factors and against the magnitude of the relief requested."). Abbott points 

out that the status quo ante will not easily be recoverable if interim infringement is 

authorized; Abbott also points out that there is no patent barrier to Teva's entry into 

commerce with its own extended release formulation instead of that of Abbott, for the basic 

patent on clarithromycin has expired. Thus the panel majority again applies a flawed 

methodology, for "Where it is clear that the moving party will suffer substantially greater 

harm by the denial of the preliminary injunction than the non-moving party would by its 

grant, it will ordinarily be sufficient that the movant has raised 'serious, substantial, difficult 

and doubtful' questions that are the proper subject of litigation." Ugine-Savoie Imphy v. 

United States, 121 F. Supp.2d 684, 689 (Ct. Int'l Trade 2000). The district court's 

consideration of this aspect was proper, and warrants appellate deference. 

Next, the panel majority states that the question of the sufficiency of money 

damages is "arguable" -- ignoring the district court's finding that this aspect may also favor 

Abbott. Instead, the majority opinion announces that this aspect will not be considered at 
05-1433 5 

all. On this accumulation of flaws, and with no reference to the district court's well 

reasoned opinion, my colleagues reverse the preliminary injunction, change the status quo, 

and authorize infringement before validity is decided. I must, respectfully, dissent. 

The Considerations Pendente Lite

At issue are claims 2, 4, and 6 of U.S. Patent No. 6,010,718 (the '718 patent) and 

claim 2 of U.S. Patent No. 6,551,616 (the '616 patent). The claims are directed to an 

extended-release formulation of erythromycin in a polymer matrix, and require that the 

minimum plasma concentration for the extended release formulation is substantially 

equivalent to that of the immediate release formulation; that is, the drug is released so as to 

be present in the plasma at the same minimum level for both the immediate release and 

extended release formulations, and with less fluctuation for the extended release product. 

In the challenge to validity, Teva and Abbott both presented extensive argument and 

briefing, citing various references. The district court, explaining its decision on the question 

of Teva's likelihood of success in proving the patents invalid, analyzed the evidence and 

concluded: 

This court finds that Teva has failed to raise a substantial question as to the 

validity of Abbott's claims 2 and 4. The prior art cited by Teva discloses 

discrete portions of the asserted claims, but Teva fails to demonstrate that 

this would be sufficient to give a person of ordinary skill in the art a 

reasonable expectation of success. Teva's prior art references reveal that 

using HPMC was a logical line of inquiry but the dissimilarities between the 

drugs with which HPMC had been successfully combined and clarithromycin 

defeat Teva's claim of obviousness. 

The district court included discussion of the issues and arguments presented by the parties, 

remarked on the uses of various known release agents, and the unpredictability of 

achieving successful extended release as to any particular product. The record shows 
05-1433 6 

 

discussion at the district court that the metabolic pathway of the active ingredient must be 

determined, as well as the physical and chemical properties and physiologic behavior and 

effectiveness of the metabolites and their interaction with the materials in the extended 

release formulation. The record shows discussion at the district court of the need for 

extended release performance that will produce an effective drug exposure in the 

bloodstream over the entire release period, and the unpredictability of this performance. 

The record shows discussion of the non-linear pharmacokinetics1 exhibited by 

clarithromycin. The district court explained its decision that Teva had not shown that it was 

likely to prove invalidity of the claimed formulations: 

This court is mindful of the Federal Circuit's warning about the risk of the 

"hindsight trap," or the post facto belief that an invention, which seems 

obvious once created, would have been obvious to people skilled in the art at 

the time. Abbott has provided ample evidence that its invention was not 

obvious and that there were many other extended release formulation 

methods known in the prior art. In fact, the existence of alternate methods 

and the attempted exploitation of some of those methods provide secondary 

considerations of nonobviousness. These factors suggest that there was a 

long-felt need for the invention, that others, including Abbott, initially failed to 

develop the invention, and go a long way to account for the commercial 

success that Abbott has unquestionably enjoyed with its BIAXIN XL product. 

1 Abbott explains that "non-linear" here means that the amount of drug in the 

blood is not directly proportional to the dosage amount, but increases disproportionately 

with higher doses. This is not a characteristic of azithromycin, the product whose 

formulation is relied on by the panel majority, as discussed infra. 

The panel majority does not discuss, and assigns no flaw, to the district court's refusal to 

apply judicial hindsight; nonetheless, the majority applies such hindsight for itself, starting 

with the template of the Abbott invention and then selecting portions of references to 
05-1433 7 

reconstruct the invention within that template. To guard against such incorrect analysis, 

precedent teaches that references cannot be selected, and selected elements from 

selected references cannot be combined, without some suggestion, motivation, or teaching 

that would make obvious that selection and that combination. See, e.g., Karsten Mfg. 

Corp. v. Cleveland Golf Co., 242 F.3d 1376, 1385, 58 USPQ2d 1286, 1293 (Fed. Cir. 2001) 

("In holding an invention obvious in view of a combination of references, there must be 

some suggestion, motivation, or teaching in the prior art that would have led a person of 

ordinary skill in the art to select the references and combine them in the way that would 

produce the claimed invention."); Brown & Williamson Tobacco Corp. v. Philip Morris Inc., 

229 F.3d 1120, 1124-25 (Fed. Cir. 2000) ("a showing of a suggestion, teaching, or 

motivation to combine the prior art references is an 'essential component of an obviousness 

holding'"). 

The panel majority acknowledges the law, but finds a motivation to make the claimed 

formulation by combining the information in Abbott's prior art Patent No. 5,705,190, which 

shows extended release formulations of clarithromycin and azithromycin in "alginate," a 

known release agent derived from seaweed, with a Pfizer publication designated WO 

95/30422, which shows the HPMC (hydroxypropyl methyl cellulose) of the '718 patent used 

with azithromycin. Abbott stated at the preliminary injunction hearing that what works for a 

product in an alginate matrix is not predictably applicable to other products; this statement 

was not contradicted. The district court analyzed the interchangeability of clarithromycin 

and azithromycin, stating: 

The questions are: how similar and dissimilar are the two molecules; and 

what are the implications of these similarities and dissimilarities to a person 

of ordinary skill in the art in light of prior art at the time of the invention. 
05-1433 8 

Specifically, would a person of ordinary skill in the art have had a reasonable 

expectation of success in creating an extended release formulation of 

clarithromycin using a hydrophilic water-soluble polymer based on the prior 

art, including the '422 patent for an extended release formulation of 

azithromycin with such a polymer? 

The court concluded that they were not so similar as to be interchangeable in the context of 

polymers like HPMC, correctly rejecting the argument that "obvious to try" can establish 

obviousness. The court stated: 

Teva's prior art references reveal that using HPMC was a logical line of 

inquiry but the dissimilarities between the drugs with which HPMC had been 

successfully combined and clarithromycin defeat Teva's claim of 

obviousness. 

My colleagues ignore the district court's analysis, offering neither deference nor 

acknowledgment. Instead, the panel majority explains that its finding of likelihood of 

success in proving obviousness is supported "not by what the '190 patent discloses but 

what it does not disclose" (emphasis in maj. op.), proposing that: "Abbott has represented 

to the U.S. Patent and Trademark Office that the differences between clarithromycin and 

azithromycin were such that azithromycin could be substituted into a controlled release 

clarithromycin composition by a person of ordinary skill in the art without undue 

experimentation." Maj. op. at 17-18. Thus my colleagues conclude that claim 4 of the '718 

patent is "vulnerable to allegations of invalidity," and find "a substantial argument" as to 

other claims. These are not the criteria of likelihood of success. 

Reversible error has not been shown in the district court's analysis, and no basis 

whatsoever has been shown for overturning the court's discretionary decision to preserve 

the status quo while the matter is litigated. Even if Teva had raised a substantial argument, 

as my colleagues find, the criteria of abuse of discretion have not been met. To support a 
05-1433 9 

change in the status quo before the merits are decided, it must be shown to be likely that 

the patent will be held invalid under the presumptions and burdens in effect at trial. The 

panel majority is incorrect in holding that it "require[s] less proof" to authorize infringement 

before the merits are decided; such a rule, whereby a patent is deprived of exclusivity 

during litigation, is not readily invoked, for it is excessively disruptive of the processes of 

law. As the Court said in eBay v. MercExchange: "As this Court has long recognized, 'a 

major departure from the long tradition of equity practice should not be lightly implied.'" 126 

S. Ct. at 1839 (quoting Weinberger v. Romero-Barcelo, 456 U.S. 305, 320 (1982)). 

Conclusion

The district court's conclusion as to the challenger's likelihood of success in 

invalidating all of the claims in suit, and the district court's view of the balance of harms, are 

well reasoned and fully supported by precedent. The district court's ruling, preserving the 

status quo during litigation, warrants, and requires, our deference. From my colleagues de

novo and incorrect contrary ruling, I must, respectfully, dissent.