Pfizer, Inc. v. Ranbaxy Laboratories Ltd.

• Decision Date: 02 August 2006
• Docket Number: No. 06-1179.,06-1179.
• Citation: 457 F.3d 1284
• Parties: PFIZER, INC., Pfizer Ireland Pharmaceuticals, Warner-Lambert Company, Warner-Lambert Company, LLC, and Warner-Lambert Export, Ltd., Plaintiffs-Appellees, v. RANBAXY LABORATORIES LIMITED and Ranbaxy Pharmaceuticals, Incorporated, Defendants-Appellants.
• Court: U.S. Court of Appeals — Federal Circuit

457 F.3d 1284

PFIZER, INC., Pfizer Ireland Pharmaceuticals, Warner-Lambert Company, Warner-Lambert Company, LLC, and Warner-Lambert Export, Ltd., Plaintiffs-Appellees, v. RANBAXY LABORATORIES LIMITED and Ranbaxy Pharmaceuticals, Incorporated, Defendants-Appellants.

No. 06-1179.

United States Court of Appeals, Federal Circuit.

August 2, 2006.

Rudolf E. Hutz, Connolly Bove Lodge & Hutz LLP, of Wilmington, Delaware, argued for plaintiffs-appellees. With him on the brief were Jeffrey B. Bove, Collins J. Seitz, Jr., Mary W. Bourke, and William E. McShane.

William R. Zimmerman, Knobbe, Martens, Olson & Bear, LLP, of Irvine, California, argued for defendants-appellants. With him on the brief were Darrell L. Olson, John P. Giezentanner, Douglas G. Muehlhauser, and Payson LeMeilleur, of Irvine, California; and Joseph M. Reisman and Darryl H. Steensma, of San Diego, California. Of counsel on the brief were Jay R. Deshmukh and George E. Heibel, Ranbaxy, Inc., of Princeton, New Jersey.

Before MICHEL, Chief Judge, SCHALL and DYK, Circuit Judges.

MICHEL, Chief Judge.

In this patent case concerning the prescription drug Lipitor®, which is used to reduce low-density lipoprotein (LDL) cholesterol levels, defendants-appellants Ranbaxy Laboratories Limited and Ranbaxy Pharmaceuticals, Inc. (collectively "Ranbaxy") appeal from a final judgment of the United States District Court for the District of Delaware. Plaintiffs-appellees Pfizer Inc., Pfizer Ireland Pharmaceuticals, Warner-Lambert Co., Warner-Lambert Co. LLC, and Warner-Lambert Export, Ltd. (collectively "Pfizer") filed four complaints, later consolidated into a single action, alleging that the product described in Ranbaxy's Abbreviated New Drug Application ("ANDA") No. 76-477 infringed United States Patent Nos. 4,681,893 and 5,273,995 under 35 U.S.C. § 271(e)(2). Ranbaxy appeals the following rulings by the district court: (1) that claim 1 of the '893 patent was infringed; (2) that the '893 patent term extension was not proven invalid; (3) that claim 6 of the '995 patent was infringed; (4) that claim 6 was not proven invalid for failure to comply with § 112, ¶ 4; as anticipated or obvious; or for non-statutory double patenting; and (5) that the '995 patent was not proven unenforceable due to inequitable conduct.

Because we agree with the district court's claim construction of claim 1 of the '893 patent, we affirm the finding of infringement. We also affirm the ruling that the '893 patent term extension was not invalid. With respect to the '995 patent, however, we reverse on the question of invalidity under § 112, ¶ 4 and find the other issues moot.

I. BACKGROUND

Stereochemistry is the study of the three-dimensional structure of molecules. Stereoisomers have the same molecular formula or atomic composition, but different spatial arrangements. Enantiomers are a pair of stereoisomers that are non-superimposable mirror images of each other and often have distinct physical properties.¹ In organic chemistry, enantiomeric pairs include compounds that have one or more chiral centers, i.e., carbon atoms with four non-identical substituent atoms or groups of atoms. For example, the enantiomers of bromochlorofluoromethane are displayed here. A solid wedge is used to indicate that the chlorine atom is projecting out of the page, while a hashed line indicates that the fluorine atom is behind the page.

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To distinguish between different enantiomers of the same compound, chemists use various naming conventions. Enantiomers are sometimes called optical isomers because a pure enantiomer rotates plane-polarized light in a particular direction. If the light rotates clockwise, then that enantiomer is labeled "(+)" or "d" for dextrorotatory; its counterpart will rotate the light counterclockwise and is labeled "(-)" or "I" for levorotatory. A racemate (or racemic mixture) is an equal mixture of two enantiomers. A racemate is labeled "(±)" because it is not optically active (i.e., will not rotate plane-polarized light in either direction since its constituent enantiomers cancel each other out). Another system labels biochemical molecules "D" or "L" (unrelated to the labels "d" and "I", described above) by reference to the isomers of glyceraldehyde. Yet another nomenclature system labels each chiral center "R" or "S" according to Cahn-Ingold-Prelog priority rules.² Racemates are designated "RS" because they are comprised of both R-enantiomers and S-enantiomers.

The terms "cis" and "trans" refer to the relative spatial arrangement of two particular substituents: "cis" means they are on the same side of a plane, while "trans" means they are on opposite sides. In organic compounds, the "plane" is typically a central ring structure. If there are two chiral centers on the aromatic ring, then there are four possible isomers: R-trans, S-trans, R-cis and S-cis. An equal mixture of R-trans and S-trans enantiomers is called the trans-racemate. An equal mixture of R-cis and S-cis enantiomers is called the cis-racemate.

* * *

Pfizer asserted claims 1-4, 8, and 9 of the '893 patent. Claim 1 is the only independent claim. It recites a compound having structural formula I (as shown), where there is a pyrrole ring on the left with four substituent groups (labeled R₁, R₂, R₃, and R₄), a pyran (or lactone) ring on the right and an alkyl chain (labeled X) joining the two rings. Claim 1 expressly defines the possible substituent groups represented by X, R₁, R₂, R₃, and R₄. Claim 1 also covers "a hydroxyl acid or pharmaceutically acceptable salts thereof, corresponding to the opened lactone ring of the compounds of structural formula I above."

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Originally, the '893 patent was to expire on May 30, 2006, but Pfizer filed for a patent term extension pursuant to 35 U.S.C. § 156. Pfizer presented evidence that the active ingredient in Lipitor® is atorvastatin calcium or [R-(R*,R*)]-2-(4-fluorophenyl)-β,δ-dihydroxy-5-(1-methyle thyl)-3-phenyl-4-[(phenylamino)carbonyl]-1H-pyrrole-1-heptanoic acid, calcium salt (2:1) trihydrate. Its structural formula is:

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On July 15, 1998, the United States Patent and Trademark Office ("PTO") agreed that this compound was within the scope of the '893 patent and extended the patent term to September 24, 2009.

As for the '995 patent, Pfizer only asserted dependent claim 6.³ The relevant claims are:

1. [R-(R*,R*)]-2-(4-fluorophenyl)-β,δ-dihydroxy-5-(1-methyle thyl)-3-phenyl-4-(phenylamino)-carbonyl]-1H-pyrrole-1-heptanoic acid⁴ or (2R-trans)-5-(4-fluorophenyl)-2-(1-methylethyl)-N,4-diphenyl-1-[2-(tetrah ydro-4-hydroxy-6-oxo-2H-pyran -2-yl)ethyl]-1H-pyrrole-3-carboxamide;⁵ or pharmaceutically acceptable salts thereof.

2. A compound of claim 1 which is [R-(R*R*)]-2-(4-fluorophenyl)-β-δ-dihydroxy-5-(1-methyle thyl)-3-phenyl-4-[(phenylamino)carbonyl]-1H-pyrrole-1-heptanoic acid.

6. The hemicalcium salt of the compound of claim 2.

A bench trial commenced on November 30, 2004. The district court issued its findings of fact and conclusions of law on December 16, 2005, concluding that both patents were infringed, not invalid and not unenforceable. Pfizer Inc. v. Ranbaxy Labs., 405 F.Supp.2d 495 (D.Del.2005). Judgment was entered on January 4, 2006. The next day, Ranbaxy filed its notice of appeal. We have jurisdiction pursuant to 28 U.S.C. § 1295(a)(1).

II. DISCUSSION

Following a bench trial, a district court's conclusions of law are reviewed de novo while its findings of fact are reviewed for clear error. Allen Eng'g Corp. v. Bartell Indus., Inc., 299 F.3d 1336, 1343-44 (Fed.Cir.2002). A factual finding is clearly erroneous if, despite some supporting evidence, "the reviewing court on the entire evidence is left with the definite and firm conviction that a mistake has been committed." United States v. U.S. Gypsum Co., 333 U.S. 364, 395, 68 S.Ct. 525, 92 L.Ed. 746 (1948).

A. '893 Patent.

1. Correct Claim Construction.

Claim construction is a question of law reviewed de novo. Cybor Corp. v. FAS Techs., Inc., 138 F.3d 1448, 1454-56 (Fed.Cir.1998) (en banc). We determine the ordinary and customary meaning of claim terms as understood by a person of ordinary skill in the art, using the methodology first set forth in Vitronics Corp. v. Conceptronic, Inc., 90 F.3d 1576, 1582-83 (Fed.Cir.1996), and reaffirmed in Phillips v. AWH Corp., 415 F.3d 1303, 1312-19 (Fed.Cir.2005) (en banc). The subsequent infringement analysis is reviewed "for clear error if performed by the court and for substantial evidence if performed by a jury." Young Dental Mfg. Co. v. Q3 Special Prods., 112 F.3d 1137, 1141 (Fed.Cir. 1997).

The parties agree that under the district court's claim construction, Ranbaxy's ANDA product infringes claim 1. On appeal, Ranbaxy argues that the district court erred in construing structural formula I "to embrace all trans-form isomers, including enantiomeric atorvastatin calcium" in lieu of accepting its proffered construction limiting claim 1 to racemates. Pfizer, 405 F.Supp.2d at 507. Instead, Ranbaxy contends that structural formula I is limited to racemates, because (1) one skilled in the art would represent a racemate by depicting one of its constituent enantiomers; (2) the specification only discloses reaction sequences that produce racemates; (3) during prosecution of foreign counterparts to the '893 patent, the patentee represented that its references to "trans" should be read as "trans-(±);" and (4) during prosecution of the '995 patent, the patentee argued that the '893 patent was limited to mixtures of enantiomers rather than the R-isomer. Thus, Ranbaxy argues, its ANDA product does not infringe claim 1 of the '893 patent because it is the R-enantiomer of atorvastatin calcium. We disagree.

It is undisputed that the drawing in claim 1 depicts an R-trans enantiomer. All...