DCT

1:19-cv-19998

Eisai R&D Management Co Ltd v. Shilpa Medicare Ltd

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I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 1:19-cv-19998, D.N.J., 06/30/2022
  • Venue Allegations: Venue is alleged to be proper as to Defendant Sun Inc. because it has a regular and established place of business in the District of New Jersey. Venue is alleged to be proper as to Defendant Sun Ltd. as a foreign corporation subject to personal jurisdiction in the district.
  • Core Dispute: Plaintiff alleges that Defendant’s Abbreviated New Drug Application (ANDA) to market a generic version of the cancer drug LENVIMA® infringes patents claiming high-purity forms of the active ingredient, lenvatinib mesylate.
  • Technical Context: The technology concerns pharmaceutical chemistry, specifically methods of manufacturing and compositions of matter for a quinoline derivative active pharmaceutical ingredient with exceptionally low levels of specific impurities.
  • Key Procedural History: This case was initiated under the Hatch-Waxman Act following Defendant’s submission of ANDA No. 213092 and its associated Paragraph IV certifications, which assert that the patents-in-suit are invalid, unenforceable, or will not be infringed by the proposed generic product.

Case Timeline

Date Event
2014-08-28 Earliest Priority Date for ’393 and ’547 Patents
2019-09-10 U.S. Patent No. 10,407,393 Issues
2019-11-11 Sun sends Paragraph IV Certification for ’393 Patent
2021-11-30 U.S. Patent No. 11,186,547 Issues
2022-01-11 Sun sends Paragraph IV Certification for ’547 Patent
2022-06-30 Amended Complaint Filed

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

U.S. Patent No. 10,407,393 - “High-Purity Quinoline Derivative and Method for Manufacturing Same”

The Invention Explained

  • Problem Addressed: The patent’s background section explains that while methods exist to produce a specific quinoline derivative with antitumor activity, the resulting product contains impurities that are difficult to remove through common purification methods like chromatography or crystallization (’393 Patent, col. 1:13-21).
  • The Patented Solution: The invention is a highly purified version of the quinoline derivative, identified as compound (IV), or a salt thereof. The key innovation is limiting the content of a specific impurity, compound (I), to a very low level—350 parts per million (ppm) by mass or less—which claims to provide a highly pure final product suitable for pharmaceutical use (’393 Patent, Abstract; col. 4:5-15).
  • Technical Importance: Achieving high purity is a critical objective in pharmaceutical manufacturing to ensure the safety, efficacy, and stability of an active pharmaceutical ingredient (API).

Key Claims at a Glance

  • The complaint asserts infringement of "one or more claims" without specifying them (Compl. ¶43). Claim 1 is the sole independent claim of the patent.
  • Claim 1 Elements:
    • A compound represented by formula (IV) or a salt thereof,
    • wherein the content of the compound represented by formula (I) is 350 ppm by mass or less.
  • The complaint reserves the right to assert dependent claims (Compl. ¶43, 44).

U.S. Patent No. 11,186,547 - “High-Purity Quinoline Derivative and Method for Manufacturing Same”

The Invention Explained

  • Problem Addressed: Similar to its parent '393 patent, this patent addresses the technical challenge of producing the quinoline derivative (compound IV) with minimal levels of specific process-related impurities that are difficult to remove using standard techniques (’547 Patent, col. 1:15-23).
  • The Patented Solution: The patent claims a methanesulfonate salt of compound (IV) that achieves an even higher level of purity than the parent patent. The invention limits the content of impurity compound (I) to 183 ppm or less and impurity compound (A-1) to 60 ppm or less, defining a composition with exceptionally low levels of specified contaminants (’547 Patent, Abstract; col. 5:1-12).
  • Technical Importance: Defining an API by its specific salt form and a stringent purity profile can provide distinct patentable subject matter over a previously known compound, particularly if the new purity level confers unexpected advantages.

Key Claims at a Glance

  • The complaint asserts infringement of "one or more claims" without specifying them (Compl. ¶52). Claim 1 is a representative independent claim.
  • Claim 1 Elements:
    • A methanesulfonate salt of a compound represented by formula (IV),
    • wherein the content of a compound represented by formula (I) is 183 ppm by mass or less.
  • The complaint reserves the right to assert dependent claims (Compl. ¶52, 53).

III. The Accused Instrumentality

Product Identification

The accused instrumentality is Sun's Abbreviated New Drug Application (ANDA) No. 213092 and the generic drug products it describes: "lenvatinib mesylate eq. 4 mg base and eq. 10 mg base oral capsules" ("Sun's ANDA Products") (Compl. ¶38).

Functionality and Market Context

The ANDA seeks FDA approval to market a generic version of Plaintiffs' branded drug, LENVIMA®, before the expiration of the patents-in-suit (Compl. ¶38). LENVIMA® is an FDA-approved treatment for several types of cancer, including thyroid cancer, renal cell carcinoma, and hepatocellular carcinoma (Compl. ¶33). The filing of an ANDA for a generic equivalent of a branded, patent-protected drug is a statutory act of infringement under 35 U.S.C. § 271(e)(2)(A) (Compl. ¶43, 52).

IV. Analysis of Infringement Allegations

The complaint does not provide a claim chart or detailed, element-by-element infringement allegations. Instead, it relies on the statutory framework of the Hatch-Waxman Act. The central infringement theory is that by filing an ANDA to seek approval for a generic version of LENVIMA®, Sun is necessarily seeking to market a product containing the same lenvatinib mesylate active ingredient (Compl. ¶38). Plaintiffs allege on information and belief that this active ingredient in Sun's ANDA Products will meet the specific purity limitations recited in the asserted claims of the ’393 and ’547 patents (Compl. ¶44, 53). The act of filing the ANDA itself constitutes the alleged infringement under 35 U.S.C. § 271(e)(2)(A).

No probative visual evidence provided in complaint.

  • Identified Points of Contention: The primary dispute will likely center on the factual question of whether Sun's proposed generic product infringes the composition claims. Sun’s Paragraph IV certification suggests it will argue for either non-infringement or invalidity (Compl. ¶38).
    • Factual Question: A central question for the court will be the actual chemical composition of Sun's ANDA Products. Discovery and expert chemical analysis will be required to determine the identity and quantity of any impurities, particularly those identified as compound (I) and compound (A-1) in the patents-in-suit.
    • Scope Questions: A potential point of contention may arise over the proper analytical methodology for measuring impurity levels in parts-per-million. The question for the court may be whether the term "content... is 350 ppm by mass or less" requires a specific testing methodology, such as the one described in the patents' examples, and whether Sun's product meets that limitation when analyzed under the appropriate standard.

V. Key Claim Terms for Construction

  • The Term: "the content of [an impurity] is [X] ppm by mass or less" (e.g., ’393 Patent, Claim 1; ’547 Patent, Claim 1).
  • Context and Importance: This quantitative limitation defines the boundary of the patent claims and is the core of the infringement dispute. The entire case may turn on whether Sun's ANDA product falls inside or outside this claimed purity level. Practitioners may focus on this phrase not for its plain meaning, but for the underlying analytical standards required to prove its satisfaction.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: A party might argue that the claim language does not recite a specific measurement technique, and therefore any scientifically valid method for detecting the impurity should be acceptable. The absence of a specific methodology in the claim itself may support an interpretation that does not limit the claim to the exact method used by the patentee during prosecution (’393 Patent, Claim 1).
    • Evidence for a Narrower Interpretation: A party might argue that the meaning of the quantitative limit is defined by the specific analytical methods disclosed in the specification, such as the detailed Liquid Chromatography conditions described in the examples of the parent patent application (’393 Patent, col. 31:42-32:14). This could support an argument that infringement can only be proven using the patentee’s disclosed methodology.

VI. Other Allegations

  • Indirect Infringement: The complaint alleges that if Sun commercially manufactures and sells its ANDA Products post-approval, it will infringe under 35 U.S.C. §§ 271(b) (inducement) and (c) (contributory) (Compl. ¶46, 55). The factual basis for this allegation is Sun's stated intent to market a generic version of LENVIMA® for the same cancer indications, which would necessarily induce physicians and patients to use the drug in a manner covered by the patents.
  • Willful Infringement: The complaint does not contain an explicit count for willful infringement. However, it establishes the basis for such a claim by alleging pre-suit knowledge of the patents. It alleges Sun was aware of the patents through their listing in the FDA's "Orange Book" and by Sun's own act of sending Paragraph IV notice letters certifying its belief of non-infringement or invalidity (Compl. ¶37, 39, 40).

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

The resolution of this ANDA litigation will likely depend on the answers to two central questions, one factual and one pertaining to claim scope:

  • A key evidentiary question will be one of analytical fact: What are the actual identities and quantities of impurities present in the lenvatinib mesylate API contained in Sun’s ANDA product? This question will be resolved through discovery, laboratory testing, and competing expert testimony.
  • A core issue will be one of methodological scope: How should the claimed parts-per-million impurity limits be measured? The case may turn on whether the claim requires adherence to the specific analytical techniques disclosed in the patent's specification or if any scientifically valid method suffices, and whether Sun's product infringes under the established standard.