TAP Pharmaceutical Products v. OWL PHARMACEUTICALS

• Citation: 419 F.3d 1346
• Decision Date: 18 August 2005
• Docket Number: 03-1635.,No. 03-1634,03-1634
• Parties: TAP PHARMACEUTICAL PRODUCTS, INC. (formerly known as Tap Holdings, Inc.), and Takeda Chemical Industries, Ltd. (now known as Takeda Pharmaceutical Company, Ltd.), Plaintiffs/Counterclaim Defendants-Cross Appellants, and Wako Pure Chemical Industries Ltd., Plaintiff-Appellee, and Abbott Laboratories, Counterclaim Defendant, v. OWL PHARMACEUTICALS, L.L.C. and Oakwood Laboratories, L.L.C., Defendants/Counterclaimants-Appellants.
• Court: United States Courts of Appeals. United States Court of Appeals for the Federal Circuit

419 F.3d 1346

TAP PHARMACEUTICAL PRODUCTS, INC. (formerly known as Tap Holdings, Inc.), and Takeda Chemical Industries, Ltd. (now known as Takeda Pharmaceutical Company, Ltd.), Plaintiffs/Counterclaim Defendants-Cross Appellants, and Wako Pure Chemical Industries Ltd., Plaintiff-Appellee, and Abbott Laboratories, Counterclaim Defendant, v. OWL PHARMACEUTICALS, L.L.C. and Oakwood Laboratories, L.L.C., Defendants/Counterclaimants-Appellants.

Nos. 03-1634, 03-1635.

United States Court of Appeals, Federal Circuit.

August 18, 2005.

William F. Cavanaugh, Jr., Patterson, Belknap, Webb & Tyler LLP, of New York, New York argued for plaintiffs/counterclaim defendants-cross appellants and plaintiff-appellee. With him on the brief was Stuart E. Pollack. Of counsel on the brief were Henry J. Renk and Bruce M. Wexler, Fitzpatrick, Cella, Harper & Scinto, of New York, New York.

Thomas H. Shunk, Baker & Hostetler LLP, of Cleveland, Ohio, argued for defendants/counterclaimants-appellants. With him on the brief was Kyle B. Fleming. Of counsel on the brief was Richard A. Sharpe, Pearne & Gordon, L.L.P., of Cleveland, Ohio.

Before NEWMAN, BRYSON, and GAJARSA, Circuit Judges.

BRYSON, Circuit Judge.

TAP Pharmaceutical Products, Inc., Takeda Chemical Industries, Ltd., and Wako Pure Chemical Industries, Ltd., (collectively, "TAP") filed suit against OWL Pharmaceuticals, L.L.C., and Oakwood Laboratories, L.L.C., (collectively, "OWL") in the United States District Court for the Northern District of Ohio. TAP alleged that OWL had infringed 12 patents owned by TAP. The allegations were based on OWL's filing of an Abbreviated New Drug Application seeking approval from the Food and Drug Administration to market a generic version of the drug leuprolide. TAP markets leuprolide, a sustained-release formulation for treating prostate cancer, under the trade name Lupron Depot. OWL counterclaimed, seeking a declaration that the patents were not infringed, were invalid, and were unenforceable. On a motion for summary judgment, the district court held that OWL did not infringe the asserted claims of U.S. Patent Nos. 5,476,663 ("the '663 patent"), 5,631,020 ("the '020 patent"), and 5,631,021 ("the '021 patent"). In a separate summary judgment ruling, the court held that OWL infringed claim 1 of U.S. Patent No. 4,728,721 ("the '721 patent") and claims 1-4 of U.S. Patent No. 4,849,228 ("the '228 patent").

At trial, the jury found that the '721 and '228 patents were not invalid and that OWL's infringement was not willful. Following the trial, the district court addressed OWL's claim that the '721 patent and the '228 patent were unenforceable due to inequitable conduct. The court rejected that claim on the ground that OWL failed to show by clear and convincing evidence that TAP had engaged in inequitable conduct by failing to cite two prior art references to the Patent and Trademark Office ("PTO") during the prosecution of the patents.

The parties have not appealed the jury's verdict on either of the issues resolved by the jury. OWL, however, has appealed from the district court's summary judgment of infringement with regard to the '721 and '228 patents, and from its decision that the '721 and '228 patents are not unenforceable. TAP has cross-appealed from the court's summary judgment of noninfringement with regard to the '663 patent, the '020 patent, and the '021 patent. We affirm the district court's judgment in all respects.

I

OWL's appeal is limited to the '721 and '228 patents. The '721 patent is directed to certain biodegradable high molecular polymers that have good aging stability and are useful as excipients in pharmaceutical preparations. The '228 patent is directed to microcapsules for use in sustained-release drug formulations in which the biodegradable high molecular polymers disclosed in the '721 patent are used as excipients. The two patents describe the use of the polymers and microcapsules in connection with sustained-release treatments in which leuprolide is delivered to patients through injection. The use of the microcapsules allows the injected drug to be delivered to the patient's system at a constant rate over a long period of time.

In prior art microcapsules, the presence of water-soluble low molecular compounds in the excipient negatively affected the sustained-release drug delivery system by causing (1) "high initial burst," i.e., the initial release of too much drug from the microcapsule; (2) low drug incorporation during the process of creating the microcapsules; and (3) poor long-term stability of the polymers used in the microcapsules. The '721 and '228 patents address those problems by reducing the levels of water-soluble low molecular compounds to a very low concentration.

A

Claim 1 of the '721 patent is representative of the claims at issue in both patents with regard to the limitation in dispute. That claim reads as follows:

A biodegradable high molecular polymer useful as an excipient in producing a pharmaceutical preparation comprising a copolymer or homopolymer of about 50-100 mole percent of lactic acid and about 50-0 mole percent of glycolic acid having a weight average molecular weight of about 2,000 to 50,000 and wherein the content of water-soluble low molecular compounds, as calculated on the assumption that each of said compounds is a monobasic acid, is less than 0.01 mole per 100 grams of said high molecular polymer.

The language in dispute for purposes of OWL's appeal on claim construction is "comprising a copolymer ... of lactic acid and ... of glycolic acid." OWL argues that the reference to copolymers of lactic acid and glycolic acid requires that the copolymers be made from lactic acid and glycolic acid as starting materials. The district court, however, construed that language to include "copolymers composed of lactic acid and glycolic acid mers produced by any method, including the use of lactide and glycolide."

Under OWL's construction, the claimed copolymers would have to be made by direct polymerization from lactic acid or glycolic acid. Under the district court's construction, the claims were not limited to copolymers made by direct polymerization. Instead, under the district court's construction, the claimed polymers could be made by a different method such as the "ring-opening" method in which lactic acid and glycolic acid are first converted into cyclic dimers, known as lactide and glycolide. The rings of those dimers are then opened by a catalyst, after which they react to form copolymer chains consisting of repeating units of lactic acid and glycolic acid.

We uphold the district court's claim construction, which was the product of a careful analysis of the claim language, the specifications of the two patents, the prosecution history, and the extrinsic evidence provided to the court. As the district court observed, neither the language of the claims nor the specification of either patent explicitly sets forth the starting materials for making the copolymers, nor do the claims or the specification require that the copolymers be produced by direct polymerization. To the contrary, while the common specification of both patents lists examples of polymerization by using lactic acid and glycolic acid as the starting materials, the specification explicitly provides that the biodegradable high molecular polymer that serves as the starting material for performing the method of the invention "may be produced by any method." '721 patent, col. 1, ll. 63-65.

The district court based its claim construction in part on treatises that recognize that copolymers of lactic acid and glycolic acid can be made either by direct polymerization or by ring opening. Based on that evidence, the district court concluded that one of ordinary skill in the art would consider the terms "copolymer of lactic acid and glycolic acid" to be synonymous with the term "copolymer of lactide and glycolide." Indeed, OWL's expert, Dr. Colin Pitt, testified that at the time the patent application was filed, a person of ordinary skill in the art would use the terms "lactic acid" and "glycolic acid" interchangeably with the terms "lactide" and "glycolide" because "the language was relatively loose at that point in time" with respect to the use of those terms.

As to the prosecution history of the two patents, OWL argues that because the prosecution files contained statements regarding the preparation of the polymers by combining lactic acid and glycolic acid, the examiner intended to exclude the use of other compounds as the appropriate starting materials for the claimed high molecular polymer. The prosecution history, however, does not exclude the use of other compounds, such as lactide or glycolide, to make the copolymer.

Finally, OWL argues that the prosecution history of the European application corresponding to the '721 patent excludes copolymers made from lactide and glycolide because TAP stated to the European examiner that the invention did not include a polymer made from lactide or glycolide. As the district court explained, however, while the applicant for the European patent characterized the claims in that manner, the European patent examiner rejected that characterization, stating that the applicant "does not appear to be correct in saying that the polymer of the present application is different from polymerized glycolide and/or lactide." In light of the European examiner's rejection, it is reasonable to conclude that TAP receded from that characterization of its claims, which it did not repeat in the course of the prosecution of its U.S. patents. It was therefore proper for the district court to attribute little weight to the statements made to the European examiner.

OWL does not dispute that under the district court's claim construction, it literally infringed TAP's patents. Because we sustain the district court's claim construction, we uphold the court's determination that OWL infringed the '721 and...