Abraxis Bioscience, Inc. v. Mayne Pharma (Usa)

• Decision Date: 15 November 2006
• Docket Number: No. 06-1118.,06-1118.
• Citation: 467 F.3d 1370
• Parties: ABRAXIS BIOSCIENCE, INC. (formerly known as AstraZeneca Pharmaceuticals LP and AstraZeneca UK Ltd.), Plaintiffs-Appellees, v. MAYNE PHARMA (USA) INC. (formerly known as Faulding Pharmaceutical Company), Defendant-Appellant.
• Court: U.S. Court of Appeals — Federal Circuit

467 F.3d 1370

ABRAXIS BIOSCIENCE, INC. (formerly known as AstraZeneca Pharmaceuticals LP and AstraZeneca UK Ltd.), Plaintiffs-Appellees, v. MAYNE PHARMA (USA) INC. (formerly known as Faulding Pharmaceutical Company), Defendant-Appellant.

No. 06-1118.

United States Court of Appeals, Federal Circuit.

November 15, 2006.

COPYRIGHT MATERIAL OMITTED

Denise L. Loring, Ropes & Gray LLP, of New York, NY, argued for plantiffs-appellees. With her on the brief were Sona De and Herbert F. Schwartz; and Robert J. Goldman, of Palo Alto, CA.

Charles A. Weiss, Kenyon & Kenyon LLP, of New York, NY, argued for defendant-appellant. With him on the brief were Thomas J. Meloro and Richard L. DeLucia. Of counsel on the brief was Jules E. Goldberg, Reed Smith, LLP, of New York, NY.

Before LOURIE, Circuit Judge, PLAGER, Senior Circuit Judge, and RADER, Circuit Judge.

LOURIE, Circuit Judge.

Mayne Pharma (USA), Inc. ("Mayne") appeals from the decision of the United States District Court for the Southern District of New York granting judgment of infringement of U.S. Patents 5,714,520 ("the '520 patent"), 5,731,355 ("the '355 patent"), and 5,731,356 ("the '356 patent"), both literally and under the doctrine of equivalents, in favor of AstraZeneca Pharmaceuticals LP and AstraZeneca UK Ltd. (collectively "AstraZeneca"). AstraZeneca Pharms. LP v. Mayne Pharma (USA) Inc., No. 02-7936, 03-6487, 2005 WL 2864666 (S.D.N.Y. Nov. 2, 2005) ("Nov. 2, 2005 Opinion"). Because the district court erred in its construction of "edetate," which was the basis upon which it found literal infringement, we reverse the court's claim construction and the court's finding of literal infringement. However, because the court did not clearly err in determining that the accused product infringes under the doctrine of equivalents, we affirm the district court's judgment.

BACKGROUND

In November 1989, AstraZeneca launched in the United States an original pharmaceutical composition used to induce and maintain general anesthesia and sedation in patients. The product was marketed and sold under the trade name DIPRIVAN® for treatment in humans and RAPINOVET® for veterinary use. The composition consists of an injectible oil-in-water emulsion containing propofol, or 2,6—diisopropyl phenol, as its active ingredient.

Typically, DIPRIVAN® is administered to patients by infusion, which involves the use of a "giving set." '520 patent, col.2 ll.56-61. A giving set involves connecting a reservoir containing the propofol emulsion with the patient's vein via the appropriate tubing. In 1990, AstraZeneca became aware that patients using DIPRIVAN® were increasingly suffering from post-operative infections. It was determined that the infections were linked to the microbial contamination of fluids contained in the DIPRIVAN® giving set. As a result, the Food and Drug Administration ("FDA") imposed a requirement that the giving sets be "changed at least every 6 or 12 hours dependent on the presentation being used." Id., col.3 ll.2-3.

AstraZeneca researchers began developing an improved formulation that would allow giving sets to be changed less frequently. The inventors of the patents in suit recommended the use of preservatives in DIPRIVAN®. They experimented with a number of preservatives, but discovered that most were ineffective. The inventors ultimately discovered that one preservative in particular, disodium edetate, was unexpectedly effective in retarding microbial growth in the propofol formulation without disrupting the oil-in-water emulsion for at least twenty-four hours. AstraZeneca subsequently developed an improved version of the original DIPRIVAN® formulation consisting of edetate, as well as all of the ingredients in the original formulation. The original DIPRIVAN® formulation and the improved formulation have identical anesthetic properties. Nov. 2, 2005 Opinion, slip op. at 4.

In March 1995, the inventors applied for a patent on their improved DIPRIVAN® formulation. In December 1995, AstraZeneca also filed a supplemental New Drug Application ("NDA") on the new formulation. It was approved on June 11, 1996, and AstraZeneca was granted three years of marketing exclusivity for the improved DIPRIVAN® formulation. AstraZeneca also requested the FDA to withdraw approval on the original DIPRIVAN® formulation, and in 1998, the FDA granted the request.

Abraxis Bioscience, Inc. ("Abraxis") is the assignee of the three asserted patents that cover the improved formulation.¹ The '520 patent, entitled "Propofol Composition Containing Edetate," was issued on February 3, 1998. The '355 and '356 patents, both entitled "Pharmaceutical Compositions of Propofol and Edetate," were issued on March 24, 1998 from divisional applications based on the '520 patent application. All three patents share a common specification. The asserted claims of the patents are claims 1-14, 16-32, and 34 of each patent, as well as claims 38 and 39 of the '520 patent.

In 1995, scientists at ESI Lederle ("ESI") learned of the reports of infection relating to original DIPRIVAN®.² ESI also learned that AstraZeneca reformulated its composition by adding an antimicrobial agent, and decided to develop a similar generic formulation. Dr. Martin Joyce of ESI led those development efforts. After reviewing AstraZeneca's '520 patent, Dr. Joyce and his colleagues screened antimicrobial agents in an effort to replace the edetate in the improved DIPRIVAN® formulation with a different agent. Id., slip op. at 8-9. Dr. Mary George, a senior formulator at ESI, advised the formulation group that the calcium trisodium salt of diethylenetriaminepentaacetic acid (pentetate), which is also referred to as DTPA, was a promising candidate as an antimicrobial agent.³

In selecting that compound, Dr. George considered a number of factors. Dr. George stated in a memorandum that the "product must be approvable as an ANDA without clinical or safety studies . . . [and] must match the reference product characteristics and stability profile" of AstraZeneca's improved formulation. J.A. at A3662. Dr. George also noted that since calcium trisodium DTPA is "structurally similar to edetate, product stability is predicted to be unaffected." Id. ESI determined that calcium trisodium DTPA produced the same characteristics and stability profile as improved DIPRIVAN®. Nov. 2, 2005 Opinion, slip op. at 9. Ultimately, calcium trisodium DTPA was chosen as the final antimicrobial additive.

ESI filed a patent application on its pharmaceutical composition and was later granted U.S. Patent 6,028,108 ("the '108 patent") on February 22, 2000. On June 28, 2002, ESI filed ANDA No. 76-452 on its generic propofol formulation. ESI included a Paragraph IV Certification asserting that the patents in suit were invalid, unenforceable, or would not be infringed by its generic propofol formulation. Pursuant to 21 U.S.C. § 355(j)(2)(B)(ii), Wyeth notified AstraZeneca by letter dated August 20, 2002 that it was seeking FDA approval for its generic propofol formulation and that it intended to commercially manufacture, use, or sell a 20 ml vial product. AstraZeneca filed the first of two patent infringement actions against Wyeth and ESI on October 4, 2002. Thereafter, Mayne, as the indirect assignee of ESI, sent AstraZeneca a notice letter dated July 15, 2003 informing AstraZeneca of its intent to commercially manufacture, use, or sell its generic propofol formulation in 50 ml and 100 ml vials. AstraZeneca initiated the second lawsuit based on this notice letter, and both actions were consolidated.

The district court issued a Markman ruling on December 28, 2004. AstraZeneca Pharms. LP v. Mayne Pharma (USA), Inc., 352 F.Supp.2d 403 (S.D.N.Y.2004). The court construed three contested terms. Only one term, "edetate," is at issue in this appeal. This term was construed by the district court as "EDTA as well as compounds structurally related to EDTA regardless of how they are synthesized." Id. at 417. After holding an eleven-day bench trial, the court entered judgment in favor of AstraZeneca, concluding that the filing of Mayne's ANDA No. 76-452 infringed the asserted claims of the patents in suit. Based on the district court's construction of "edetate" as encompassing structural analogs of EDTA, the court found that Mayne's generic propofol formulation literally infringed claims 1 and 3-14 of the asserted patents, and claim 38 of the '520 patent. Additionally, the court determined that Mayne's formulation infringed claims 1-14, 16-32, and 34 of the asserted patents, and claims 38 and 39 of the '520 patent under the doctrine of equivalents. Mayne timely appealed. We have jurisdiction pursuant to 28 U.S.C. § 1295(a)(1).

DISCUSSION

Claim construction is an issue of law, Markman v. Westview Instruments, Inc., 52 F.3d 967, 970-71 (Fed.Cir.1995) (en banc), that we review de novo. Cybor Corp. v. FAS Techs., Inc., 138 F.3d 1448, 1456 (Fed.Cir.1998) (en banc). The district court's determination of infringement, in contrast, is a question of fact that we review for clear error. Centricut, LLC v. Esab Group, Inc., 390 F.3d 1361, 1367 (Fed.Cir.2004). A determination of infringement requires a two-step analysis. "First, the court determines the scope and meaning of the patent claims asserted, and then the properly construed claims are compared to the allegedly infringing device." Cybor, 138 F.3d at 1454 (citations omitted). "A finding is `clearly erroneous' when although there is evidence to support it, 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).

I. Claim Construction

Central to the disposition of this appeal is the construction of the term "edetate," which is a limitation in each of the asserted claims. Claim 1 of the '520 patent is a representative claim. It reads, in pertinent part, as follows:

1. A sterile...