DCT

1:25-cv-01260

Bayer Healthcare Pharma Inc v. Zydus Lifesciences Ltd

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Key Events
Complaint

I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: Bayer HealthCare Pharmaceuticals Inc. v. Zydus Lifesciences Limited, 1:25-cv-01260, D. Del., 10/15/2025
  • Venue Allegations: Venue is alleged to be proper for Zydus Lifesciences, a foreign corporation, in any district where it is subject to personal jurisdiction. For Zydus Pharmaceuticals (USA) Inc., venue is based on its business in Delaware, its qualification to do business in the state, and its representation that it would not contest venue for the purposes of this action.
  • Core Dispute: Plaintiff alleges that Defendant’s filing of an Abbreviated New Drug Application (ANDA) to market a generic version of Plaintiff’s KERENDIA® (finerenone) drug constitutes an act of infringement of a patent covering a method for preparing and purifying the active pharmaceutical ingredient.
  • Technical Context: The technology concerns a specific, multi-step chemical synthesis process designed for the efficient, large-scale industrial manufacturing of finerenone, a non-steroidal mineralocorticoid receptor antagonist used in treatments for chronic kidney disease and heart failure.
  • Key Procedural History: The patent-in-suit is a reissue of U.S. Patent No. 10,336,749, with original claims 1-13 not forming part of the reissued patent. The litigation was triggered by Defendant’s Paragraph IV Notice Letter, which, according to the complaint, asserted that certain claims of the patent-in-suit are invalid as obvious and other claims will not be infringed by the commercial manufacture of its proposed generic product.

Case Timeline

Date Event
2015-08-21 RE’826 Patent Priority Date
2019-07-02 Original U.S. Patent No. 10,336,749 Issue Date
2021-07-09 FDA Approval of KERENDIA® (NDA No. 215341)
2024-02-06 U.S. Reissue Patent No. RE49,826 Issue Date
2025-09-04 Zydus Paragraph IV Notice Letter Sent
2025-09-05 Zydus Paragraph IV Notice Letter Received by Bayer
2025-10-15 Complaint Filing Date

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

U.S. Reissue Patent No. RE49,826 - "Method for the preparation of (4S)-4-(4-cyano-2-methoxyphenyl)-5-ethoxy-2,8-dimethyl-1,4-dihydro-1-6-naphthyridine-3-carboxamide and the purification thereof for use as an active pharmaceutical ingredient"

The Invention Explained

  • Problem Addressed: The patent’s background section describes prior art methods for synthesizing the finerenone compound as mere "research scale" processes unsuitable for industrial production (RE’826 Patent, col. 2:3-5). These earlier methods allegedly suffered from low overall yield, the need for "many intermediate chromatographic purifications," high consumption of reagents, and process technology difficulties that made them impractical for large-scale manufacturing (RE’826 Patent, col. 2:48-58).
  • The Patented Solution: The patent discloses a "novel and improved process" for preparing finerenone that is designed to be industrially practicable (RE’826 Patent, col. 2:60-63). The described synthesis affords the target compound in high yield and purity while avoiding the costly and laborious chromatographic purification of intermediates, as illustrated in the overall reaction pathway shown in Scheme 2 (RE’826 Patent, col. 5:1-67).
  • Technical Importance: This process enables the efficient and reproducible large-scale manufacturing of finerenone, the active pharmaceutical ingredient in KERENDIA®, a drug indicated for serious cardiovascular and renal conditions (Compl. ¶¶34, 37).

Key Claims at a Glance

The complaint alleges infringement of "one or more claims" but does not specify which claims will be asserted (Compl. ¶55). The complaint notes that Defendant’s Paragraph IV letter challenged claims 14-26 and 30 as obvious and claims 27-29 as not infringed (Compl. ¶45). Claim 2 is the first independent claim of the patent.

  • Independent Claim 2:
    • A process for preparing a compound of the formula (I)
    • comprising separating a racemic compound of the formula (XIII) into its enantiomers,
    • where the compound of the formula (XIII) is prepared by reacting a compound of the formula (XVIII) with an orthoester (XX),
    • where R may be H or methyl.

III. The Accused Instrumentality

  • Product Identification: The accused instrumentality is "Zydus's ANDA Product," identified as generic finerenone tablets (10 mg and 20 mg) for which Zydus seeks FDA approval under ANDA No. 220636 (Compl. ¶¶1, 43).
  • Functionality and Market Context: The product is a generic version of Bayer's KERENDIA®, a non-steroidal mineralocorticoid receptor antagonist (nsMRA) (Compl. ¶¶1, 34). It is indicated for reducing the risk of kidney function decline, kidney failure, cardiovascular death, and hospitalization for heart failure in certain patient populations (Compl. ¶34). The complaint alleges that Zydus intends to commercially manufacture and sell this product in the U.S. before the expiration of the RE’826 Patent (Compl. ¶41).
    No probative visual evidence provided in complaint.

IV. Analysis of Infringement Allegations

The complaint does not provide sufficient detail for analysis of infringement on a claim-element-by-element basis. The infringement allegation is a statutory one under 35 U.S.C. § 271(e)(2)(A), where the act of infringement is the submission of an ANDA seeking approval to market a drug claimed in a patent, or a drug that will be made by a process claimed in a patent, before the patent's expiration (Compl. ¶53). The complaint alleges that Zydus's ANDA seeks approval to engage in the commercial manufacture of a product claimed in the RE’826 Patent (Compl. ¶54).

  • Identified Points of Contention: The central dispute will concern the specific manufacturing process detailed in Zydus's confidential ANDA filing. The key technical and legal questions will include:
    • Scope Questions: Do the process steps Zydus intends to use to synthesize its generic finerenone fall within the scope of the asserted claims of the RE’826 Patent?
    • Technical Questions: What evidence exists that Zydus's process involves the specific reaction of a compound of formula (XVIII) with an orthoester (XX) to form a racemic intermediate (XIII), followed by a step of "separating" that racemate into its enantiomers, as required by claim 2?

V. Key Claim Terms for Construction

  • The Term: "separating a racemic compound of the formula (XIII) into its enantiomers" (from claim 2)
  • Context and Importance: This term defines the critical step for obtaining the correct stereoisomer of the active ingredient. The infringement analysis may turn on whether Zydus's method for isolating the desired (4S)-enantiomer is covered by this language. For example, a dispute could arise if Zydus employs an asymmetric synthesis that produces the desired enantiomer directly, which might not be considered "separating a racemic compound." Practitioners may focus on this term because alternative chemical pathways that avoid a classical resolution of a racemic mixture are common in pharmaceutical manufacturing.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The plain language of the claim term "separating" is not explicitly limited to any particular technique.
    • Evidence for a Narrower Interpretation: The specification provides specific examples of separation using chiral chromatography, including Simulated Moving Bed (SMB) systems on a "Chiralpak AS-V, 20 µm" stationary phase (RE’826 Patent, col. 12:62-65; col. 39:24-42). A party could argue that the claims should be interpreted in light of these specific disclosures, potentially limiting the scope of "separating" to chromatographic resolution techniques.

VI. Other Allegations

  • Indirect Infringement: The complaint alleges that upon FDA approval, Zydus will actively induce and contribute to the infringement of one or more claims of the RE’826 Patent (Compl. ¶56). It further alleges that Zydus knows and intends for healthcare professionals and patients to use the product in accordance with its labeling, which will contribute to or induce infringement (Compl. ¶64).
  • Willful Infringement: The complaint alleges that Zydus has acted with "full knowledge of the RE’826 Patent" and without a reasonable basis for believing its generic product would not infringe (Compl. ¶57). This allegation is based on Zydus’s submission of the Paragraph IV Certification.

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

  • A core issue will be one of process comparison: Does the confidential manufacturing process described in Zydus’s ANDA No. 220636 practice each step of the chemical synthesis recited in the asserted claims of the RE’826 patent, or does it utilize a distinct, non-infringing pathway to produce finerenone?
  • A key legal question will be one of claim scope: Will the term "separating a racemic compound," as used in the patent, be construed broadly to encompass any method of isolating the desired enantiomer, or will it be limited by the specification's detailed disclosure of specific chromatographic resolution technologies? The resolution of this question may determine whether Zydus's process, if different from the disclosed embodiments, still falls within the patent's scope.