DCT

1:07-cv-11614

Mitsubishi Chemical Corp v. Barr Laboratories Inc

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Key Events
Complaint

I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 1:07-cv-11614, S.D.N.Y., 12/28/2007
  • Venue Allegations: Plaintiffs allege venue is proper because Defendant Barr Laboratories, Inc. conducts business in the Southern District of New York, is registered to do so, and by filing its Abbreviated New Drug Application (ANDA), committed a tortious act outside the state with foreseeable consequences within the state.
  • Core Dispute: Plaintiffs allege that Defendant’s filing of an ANDA to market a generic version of Argatroban Injection constitutes an act of infringement of a patent covering the drug’s specific formulation.
  • Technical Context: The technology concerns pharmaceutical formulations for injectable drugs, specifically a solvent system designed to increase the solubility and concentration of the anticoagulant drug Argatroban.
  • Key Procedural History: This action was initiated under the Hatch-Waxman Act following Defendant’s submission of ANDA No. 79-238 and a corresponding Paragraph IV certification letter, dated November 16, 2007, which asserted that the patent-in-suit is invalid, unenforceable, or will not be infringed by its proposed generic product. The patent-in-suit received a term extension and is alleged to expire on June 30, 2014.

Case Timeline

Date Event
1987-07-28 '052 Patent Priority Date
1993-05-25 '052 Patent Issue Date
2000-06-30 FDA Approval of NDA for Argatroban Injection
2007-11-16 Date of Defendant's Paragraph IV Certification Letter
2007-12-28 Complaint Filing Date

II. Technology and Patent(s)-in-Suit Analysis

U.S. Patent No. 5,214,052 - Method for Dissolving Arginineamides and Pharmaceutical Compositions Containing Them

  • Patent Identification: U.S. Patent No. 5,214,052, "Method for Dissolving Arginineamides and Pharmaceutical Compositions Containing Them," issued May 25, 1993.

The Invention Explained

  • Problem Addressed: The patent's background section describes that certain arginineamides, which have useful anti-thrombotic properties, are difficult to prepare in high-concentration solutions due to their "poor solubility in water." (’052 Patent, col. 1:24-26). This characteristic makes them unsuitable for administration as a high-concentration injection. (’052 Patent, col. 1:26-30).
  • The Patented Solution: The invention claims to solve this solubility problem by dissolving the arginineamide compound in a specific three-part solvent system comprising an alcohol (such as ethanol), water, and a saccharide. (’052 Patent, col. 1:44-49). This combination is described as enabling the creation of a high-concentration solution suitable for injection, which could not be achieved with water alone. (’052 Patent, col. 4:22-28).
  • Technical Importance: This formulation technique provides a method to deliver a known therapeutic agent (Argatroban) in a clinically effective and stable injectable form at concentrations that were previously difficult to achieve. (’052 Patent, col. 1:21-30).

Key Claims at a Glance

  • The complaint alleges infringement of at least one claim and notes Defendant’s invalidity contentions against claims 1-4. (Compl. ¶¶ 21, 27). The asserted independent claims are:
    • Independent Claim 1 (Method):
      • A method for dissolving an arginineamide, comprising:
      • dissolving N²-arylsulfonyl-L-argininamide represented by formula (I) and/or its salt
      • in a solvent containing ethanol, water and a saccharide.
    • Independent Claim 3 (Composition):
      • A pharmaceutical composition for injection, comprising:
      • N²-arylsulfonyl-L-argininamide represented by formula (I) and/or its salt
      • together with ethanol, water and a saccharide.
  • The complaint’s use of the phrase "at least one of the claims" suggests the possibility that dependent claims may also be asserted. (Compl. ¶ 27).

III. The Accused Instrumentality

Product Identification

  • The accused instrumentality is Defendant Barr’s proposed generic Argatroban Injection, for which it seeks FDA approval through ANDA No. 79-238 (the "Proposed Product"). (Compl. ¶¶ 16-17).

Functionality and Market Context

  • The Proposed Product is an anticoagulant intended for uses such as the treatment of thrombosis in patients with heparin-induced thrombocytopenia. (Compl. ¶ 14). The complaint alleges that Barr’s product is a "generic equivalent[]" of the Plaintiffs' branded Argatroban Injection and is "bioequivalent" to it. (Compl. ¶¶ 17-18). The act of infringement alleged is the filing of the ANDA itself, which seeks approval to market this product before the expiration of the ’052 Patent. (Compl. ¶ 26).

IV. Analysis of Infringement Allegations

No probative visual evidence provided in complaint.

The complaint does not contain a detailed claim chart. The infringement theory is based on the statutory act of infringement under 35 U.S.C. § 271(e)(2), which is the filing of an ANDA for a product that would infringe if commercially manufactured. The core allegation is that for Barr’s product to be a bioequivalent generic of Plaintiffs’ Argatroban Injection, it must necessarily embody the claimed formulation. The following chart summarizes this inferred theory for composition claim 3.

’052 Patent Infringement Allegations

Claim Element (from Independent Claim 3) Alleged Infringing Functionality Complaint Citation Patent Citation
N²-arylsulfonyl-L-argininamide represented by formula (I) ... and/or its salt Defendant's Proposed Product is a generic "Argatroban Injection," where Argatroban is the common name for the compound of formula (I). ¶7, ¶16 col. 5:27-41
together with ethanol, water and a saccharide The complaint alleges the Proposed Product is a "generic equivalent[]" of Plaintiffs’ approved Argatroban Injection, which is alleged to be formulated with these components. ¶7, ¶18 col. 5:42-43
  • Identified Points of Contention:
    • Factual Question: The central factual dispute for infringement will be the precise formulation of Barr's Proposed Product as detailed in its confidential ANDA. The key question is: "Does the confidential formulation described in ANDA No. 79-238 contain ethanol, water, and a 'saccharide' as required by the independent claims?"
    • Technical Question: A related technical question is whether a formulation can be "bioequivalent" to the branded Argatroban Injection, as Barr's product is alleged to be, without using the claimed three-component solvent system. (Compl. ¶ 17).

V. Key Claim Terms for Construction

The complaint does not identify specific claim terms in dispute, but based on the technology and typical ANDA litigation strategies, the following term may be central.

  • The Term: "saccharide"
  • Context and Importance: The definition of "saccharide" is critical. If Barr’s formulation includes a solubilizing agent that falls outside the court’s construction of this term, it could provide a basis for a non-infringement defense. Practitioners may focus on this term because the choice of excipients is a common way to design around formulation patents.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The specification provides an inclusive list, stating the term includes "monosaccharides, oligosaccharides, polysaccharides and their reduced derivatives (for example sugaralcohol) which are soluble in water." (’052 Patent, col. 4:60-63). This language may support a broad definition covering a wide class of sugar-based compounds.
    • Evidence for a Narrower Interpretation: Dependent claims 2 and 4 explicitly narrow the term to "at least one member selected from the group consisting of sorbitol, glucose, glycerin and sucrose." (’052 Patent, col. 6:23-26; col. 6:64-67). A party could argue that this explicit recitation in dependent claims suggests a narrower scope for the term in the independent claim, or that the term should be limited by the "particularly preferable" embodiment of D-sorbitol. (’052 Patent, col. 4:67-68).

VI. Other Allegations

  • Indirect Infringement: The complaint alleges both induced and contributory infringement. The inducement allegation is based on the assertion that Barr knows or should know that the sale of its Proposed Product will cause others (e.g., healthcare professionals) to directly infringe the patent. (Compl. ¶¶ 31-33). The contributory infringement allegation asserts that the Proposed Product is a material part of the invention, is especially made for an infringing use, and is not a staple article of commerce with substantial non-infringing uses. (Compl. ¶¶ 37, 41).
  • Willful Infringement: The complaint does not contain an explicit allegation of willful infringement. However, Plaintiffs do request an award of attorneys' fees pursuant to 35 U.S.C. § 285, which is reserved for exceptional cases. (Compl. p. 10, ¶(e)). The allegation that Barr received a notice letter may serve as a factual predicate for such a request. (Compl. ¶ 19).

VII. Analyst’s Conclusion: Key Questions for the Case

The resolution of this case will likely depend on the court's findings on three central issues:

  1. A primary issue will be one of validity: as indicated by Defendant's Paragraph IV letter, the case may center on whether the claimed combination of Argatroban with an ethanol, water, and saccharide solvent system would have been obvious to a person of ordinary skill in the art in view of the prior art references identified by Defendant. (Compl. ¶ 21).
  2. A key factual question will be one of formulation identity: does the specific, confidential formulation in Barr’s ANDA in fact contain all three components of the claimed solvent system (ethanol, water, and a "saccharide"), or has Barr successfully designed around the patent by omitting or replacing one of these elements?
  3. A dispositive legal question may be one of definitional scope: how will the court construe the claim term "saccharide"? A broad construction encompassing many types of excipients would favor the Plaintiffs, while a narrow construction limited to the patent’s specific examples could create a path for a non-infringement finding for the Defendant.