Aventis Pharma S.A. v. Amphastar Pharmaceuticals, Inc.

475 F. Supp. 2d 970, 2007 U.S. Dist. LEXIS 15426, 2007 WL 575836
District Court, C.D. California·Decided February 8, 2007·No. EDCV03 887 MRP FLAX, EDCVO4 333 MRP PLAX·Published·Cited by 3 cases

Opinion

MEMORANDUM OF DECISION FINDING IN FAVOR OF DEFENDANTS AMPHASTAR PHARMACEUTICALS, INC. AND TEVA PHARMACEUTICALS USA, INC. ON THE RELATED ISSUES OF INTENT TO DECEIVE THE PATENT AND TRADEMARK OFFICE AND INEQUITABLE CONDUCT

PFAELZER, District Judge.

I. INTRODUCTION

This case was commenced before District Judge Robert J. Timlin. Aventis Pharma S.A. and Aventis Pharmaceuticals, Inc. (collectively, “Aventis” 1 ) brought suit against Amphastar Pharmaceuticals, Inc. (“Amphastar”) and Teva Pharmaceuticals USA, Inc. (“Teva”) (collectively, “Defendants”) for infringement of Aventis’ patent, U.S. Patent No. 5,389,618, and its replacement, U.S. Reissue Patent No. 38,743 (collectively, “the ’618 patent”). The case was transferred to this Court for all further proceedings on June 27, 2006. A bench trial on inequitable conduct was held December 4 through December 8, 2006. The Court limited its inquiry to Aventis and its agents’ intent in failing to disclose highly material information to the United States Patent and Trademark Office (“PTO”). Based on consideration of the evidence adduced at trial and the post-trial arguments made by counsel, the Court concludes as follows:

II. BACKGROUND

Heparin is an anticoagulant used to decrease the clotting ability of the blood. Chemically, it is a heterogeneous mixture of straight-chain anionic mucopolysacchar-ides having anticoagulant properties. Low molecular weight heparin (“LMWH”) is synthesized by various methods of heparin fractionation or depolymerization. These methods break down heparin’s long, heavy polysaccharide molecules, yielding smaller, less massive chains in more homogenous proportions. The resulting mixtures consist of shorter chains of polysaccharides having lower average molecular weights.

The ’618 patent claims a range of defined LMWH mixtures. These encompass the drug formulation, enoxaparin, approved by the United States Food and Drug Administration (“FDA”) as an anticoagulant in diseases featuring venous *973 thromboses. Aventis is the international pharmaceutical company that manufactures enoxaparin, which it markets under the brand name Lovenox®. Enoxaparin was approved in France in 1987. By 1989, it had “taken the French market by storm” and achieved commercial success throughout Europe. Aventis exerted a monopoly position in the European market for enoxaparin in the 1980s by virtue of European Patent 40,144 (“EP ’144”), which issued in 1984 and broadly claimed undefined LMWH mixtures invented by J. Mar diguian.

Serious challenges to EP '144 soon threatened this position. Opposition proceedings initiated in the mid-1980s before the European Patent Office to revoke EP ’144 as devoid of novelty had, by 1989, proved successful — the opposition was allowed, and the revocation of EP ’144 became effective in October 1990. Enoxapa-rin did not have patent coverage in the U.S. at this time. Aventis had been forced to abandon its U.S. counterpart application to EP ’144 in 1984 when it had no argument to oppose the PTO’s prior-art rejections. Notwithstanding this deficit, Aven-tis filed its New Drug Application (“NDA”) with the FDA in July 1991 to obtain marketing approval for enoxaparin in the U.S. In concert, Aventis sought to protect enox-aparin in the U.S. with an EP ’144 successor: a formulation of enoxaparin invented by Roger Debrie (the “Debrie” or “ ’618” product). 2 This was the subject of the ’618 prosecution. The high cost of FDA approval generated substantial pressure on Aventis to succeed. Internal Aventis documents reveal its commitment of “significant financial and human resources” to the “enoxaparin USA-patent situation.”

The ’618 prosecution involved successive rounds of rejection and appeal. The Patent Examiner (“PE”) issued three Office Actions dated April 2, 1992 (“First Office Action”), October 16, 1992 (“Second Office Action”), and March 2, 1993 (“Third Office Action”). Each rejected the Debrie formulation under 35 U.S.C. § 102 as anticipated by or, in the alternative, under 35 U.S.C. § 103 as obvious in light of Mardig-uian EP T44. The keystone of Aventis’ strategy for overcoming the PE’s rejections was to distinguish the Debrie LMTWH based on its purportedly superior pharmacokinetic properties — particularly, its longer plasma half-life. The ’618 patent discloses that “[t]he processes described in the prior art, and especially in EP ’144, do not permit the production of mixtures possessing the requisite pharmacological properties for improved therapeutic applications, namely, a sufficiently long plasma half-life, a fairly high absorption rate, a high bioavailability or alternatively, a low clearance.” In support of these assertions, Aventis directed the PE’s attention to Example 6 of the ’618 patent (“Example 6”) and the half-life analysis presented therein. 3 Aventis also submitted two expert declarations from its em *974 ployee, French scientist Dr. Andre Uzan (“Dr.Uzan”), who was responsible for the data underlying Example 6. 4

Throughout the prosecution, Aventis and Dr. Uzan affirmatively represented that Example 6 “clearly demonstratefd]” a significantly longer plasma half-life for the Debrie LMWH compared to Mardiguian EP T44. At no time, however, did Aventis or Dr. Uzan disclose at what dosage the half-life comparisons in Example 6 had been made. Subparagraph (3) of Example 6 omitted the experimental dose of EP 144. In his Second Declaration, Dr. Uzan presented five tables: Tables I, X, and XI referred to the ’618 product, while Tables A and III referred to Mardiguian EP 144. Again, Table III failed to disclose the dose. In fact, Dr. Uzan had compared a 60 mg dose of Mardiguian EP 144 to a lpO mg dose of the Debrie product. However, comparing the 60 mg dose amount of Mardiguian EP 144 to the 60 mg dose amount of the Debrie product results in a far closer mean half-life. 5 The difference is not statistically significant.

III. PRIOR PROCEEDINGS

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Aventis Pharma S.A. v. Amphastar Pharmaceuticals, Inc., 475 F. Supp. 2d 970, 2007 U.S. Dist. LEXIS 15426, 2007 WL 575836 (C.D. Cal. 2007).

475 F. Supp. 2d 970 (Aventis Pharma S.A. v. Amphastar Pharmaceuticals, Inc.) — published by Counsel Stack Legal Research, free access to 12M+ legal documents.

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