DCT

1:17-cv-07342

Mitsubishi Tanabe Pharma Corp v. Prinston Pharma Inc

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I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 1:17-cv-07342, D.N.J., 09/21/2017
  • Venue Allegations: Venue is alleged to be proper in the District of New Jersey because Defendant Prinston Pharmaceuticals, Inc. maintains its principal place of business in the state, is registered as a wholesaler there, and has a regular and established place of business within the district.
  • Core Dispute: Plaintiffs allege that Defendant’s filing of an Abbreviated New Drug Application (ANDA) to market a generic version of the diabetes drug INVOKANA® constitutes an act of infringement of a patent covering a specific crystalline form of the active ingredient, canagliflozin.
  • Technical Context: The patent concerns a specific crystalline polymorph of a pharmaceutical compound, a critical aspect of drug development that influences manufacturing consistency, stability, and bioavailability.
  • Key Procedural History: This lawsuit was initiated under the Hatch-Waxman Act, triggered by Defendant’s submission of an ANDA with a Paragraph IV certification, asserting that the patent-in-suit is invalid or not infringed. The patent is listed in the FDA's "Orange Book" for the brand-name drug INVOKANA®. The complaint notes that Defendant was previously sued in the same district and availed itself of the courts by asserting counterclaims in other patent matters.

Case Timeline

Date Event
2006-12-04 '202 Patent Priority Date
2013-08-20 '202 Patent Issue Date
2017-08-16 Defendant’s ANDA Notification Letter
2017-09-21 Complaint Filing Date

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

U.S. Patent No. 8,513,202 - Crystalline form of 1-(β-D-glucopyransoyl)-4-methyl-3-[5-(4-fluorophenyl)-2-thienylmethyl]benzene hemihydrate

The Invention Explained

  • Problem Addressed: The patent's background section notes "difficulties in obtaining a crystal form" of the underlying therapeutic compound, canagliflozin, from organic solvents ('202 Patent, col. 1:61-63). For a drug to be commercially viable, it must be produced in a pure, stable, and crystalline form to meet "exacting pharmaceutical requirements and specifications" for formulation and manufacturing ('202 Patent, col. 1:50-56).
  • The Patented Solution: The invention is a specific, novel crystalline structure of canagliflozin, specifically a "hemihydrate," which incorporates water molecules into its crystal lattice ('202 Patent, Abstract). This specific crystalline form is described as having "good handling qualities and characteristics" and being producible "in a manner reproducible on a commercial scale," thus solving the previously noted manufacturing and purity challenges ('202 Patent, col. 1:64-65, col. 2:21-23). The patent identifies this novel form through its unique analytical properties, such as its X-ray powder diffraction pattern and its infra-red (IR) spectrum ('202 Patent, col. 2:29-39).
  • Technical Importance: The discovery of a stable, reproducible polymorph of an active pharmaceutical ingredient is a critical step in drug development, directly impacting a product's shelf-life, batch-to-batch consistency, and therapeutic efficacy ('202 Patent, col. 1:50-60).

Key Claims at a Glance

  • The complaint asserts independent claim 1 and dependent claims 3-5 (Compl. ¶32).
  • Independent Claim 1 requires:
    • A crystalline form
    • of 1-(β-D-glucopyranosyl)-4-methyl-3-[5-(4-fluorophenyl)-2-thienylmethyl]benzene hemihydrate
    • having an infra-red spectrum in mineral oil comprising the following main peaks: 1626, 1600, 1549, and 1507 cm⁻¹

III. The Accused Instrumentality

Product Identification

The accused instrumentality is the generic drug product described in Prinston’s Abbreviated New Drug Application (ANDA) No. 210514 (the "Prinston ANDA Product") (Compl. ¶1).

Functionality and Market Context

The Prinston ANDA Product is a generic version of Plaintiffs' INVOKANA® (canagliflozin) tablets, intended as an "adjunct to diet and exercise to improve glycemic control in adults with type 2 diabetes mellitus" (Compl. ¶11, ¶26). The complaint alleges infringement not based on a currently marketed product, but on the statutory act of filing the ANDA seeking FDA approval to market this generic product before the expiration of the '202 Patent (Compl. ¶31). No probative visual evidence provided in complaint.

IV. Analysis of Infringement Allegations

The complaint does not provide a claim chart exhibit. The infringement theory is presented in prose. The central allegation is that Prinston's submission of ANDA No. 210514 for a generic version of canagliflozin constitutes an act of infringement under 35 U.S.C. § 271(e)(2) (Compl. ¶31). Plaintiffs allege on information and belief that the product described in the ANDA, if commercially manufactured or sold, would infringe claims 1 and 3-5 of the '202 Patent (Compl. ¶32). The core of this allegation is that the active pharmaceutical ingredient in Prinston's proposed product is the specific "crystalline form of ... hemihydrate" of canagliflozin that is claimed in the '202 patent, as identified by the specific IR spectrum peaks recited in claim 1 (Compl. ¶27; '202 Patent, col. 8:14-18).

Identified Points of Contention

  • Technical Questions: A primary factual dispute will center on whether the active pharmaceutical ingredient in Prinston’s proposed generic product is, in fact, the claimed crystalline hemihydrate. The case will likely depend on analytical testing (e.g., IR spectroscopy, X-ray diffraction, thermogravimetric analysis) performed during discovery to compare Prinston’s compound to the claimed properties. The complaint itself offers no such evidence, stating that "discovery/testing will show" infringement (Compl. ¶27).
  • Scope Questions: The interpretation of claim 1's phrase "comprising the following main peaks" could be a point of contention. A dispute may arise over whether this language permits the presence of other, unlisted peaks in the IR spectrum of an accused product, or if the claim should be interpreted more narrowly. The precision and standard error of the analytical techniques used to measure these properties may also become a focus of the dispute.

V. Key Claim Terms for Construction

The complaint does not provide sufficient detail for a definitive analysis of terms likely to be disputed. However, based on the technology and claim language, certain terms are central to the dispute.

  • The Term: "crystalline form of ... hemihydrate"
  • Context and Importance: This term is the foundation of the patent's claim to novelty. The entire infringement analysis hinges on whether Prinston's product embodies this specific solid-state form of canagliflozin, which is defined as being both "crystalline" and a "hemihydrate" (a crystal structure incorporating one water molecule for every two drug molecules). Practitioners may focus on this term because the patent was obtained specifically to protect this polymorphic form against the background of the known, non-crystalline compound ('202 Patent, col. 1:61-63).
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: A party could argue that the term should be given its plain and ordinary meaning, and that claim 1 itself provides the operative definition by listing the required IR peaks. Under this view, any crystalline hemihydrate exhibiting those peaks would infringe, regardless of other physical properties or the method of manufacture.
    • Evidence for a Narrower Interpretation: The specification provides detailed examples of how the claimed form is made and characterized, including a theoretical water content of 1.98% and a measured mass loss of 1.705% by thermogravimetric analysis ('202 Patent, col. 3:28-32, Example 1). A party could argue these specific embodiments and detailed characterizations limit the scope of the term to a crystalline form that exhibits properties closely matching those described in the examples.

VI. Other Allegations

  • Indirect Infringement: The complaint includes allegations of induced and contributory infringement under 35 U.S.C. § 271(b) and (c), respectively (Compl. ¶32). The factual basis alleged is that Prinston, by seeking to market its generic product with a label instructing its use, would cause and contribute to infringement by medical providers and patients (Compl. ¶32).
  • Willful Infringement: The complaint does not contain an explicit count for willful infringement. However, it lays a potential foundation for such a claim by alleging that "Prinston has had knowledge of the '202 patent since at least the date it submitted the Prinston ANDA" (Compl. ¶33).

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

  1. A central evidentiary question will be one of physical identity: Will discovery and analytical testing demonstrate that the canagliflozin API described in Prinston's ANDA is the specific "crystalline form of... hemihydrate" as defined by the IR spectrum and other properties claimed in the '202 patent?
  2. A core issue will be one of validity: As Prinston has asserted invalidity, the case will likely examine whether the claimed crystalline form is novel and non-obvious over the prior art, which includes the disclosure of the amorphous canagliflozin compound itself. The dispute may turn on whether the isolation and characterization of this specific polymorph represented a patentable advance.