DCT

1:25-cv-01280

Bayer Healthcare Pharma Inc v. Macleods Pharma Ltd

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Key Events
Complaint

I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 1:25-cv-01280, D. Del., 10/20/2025
  • Venue Allegations: Venue is alleged as proper for Macleods Ltd. as it is a foreign corporation subject to personal jurisdiction in the district. Venue is alleged as proper for Macleods USA because it is incorporated in Delaware.
  • 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 product constitutes an act of infringement of a patent covering a specific crystalline form of the active ingredient and methods of its preparation.
  • Technical Context: The dispute centers on the chemical synthesis and purification of finerenone, a non-steroidal mineralocorticoid receptor antagonist used to treat chronic kidney disease and heart failure associated with type 2 diabetes.
  • Key Procedural History: The patent-in-suit is a reissue of U.S. Patent No. 10,336,749, with the reissued patent comprising claims 14-30 of the original patent. The litigation was triggered by Defendant sending Plaintiff a Paragraph IV Notice Letter, asserting that its proposed generic product would not infringe the patent-in-suit and/or that the patent claims are invalid.

Case Timeline

Date Event
2015-08-21 Earliest Priority Date for RE49,826 Patent
2019-07-02 Original U.S. Patent No. 10,336,749 Issues
2021-07-09 FDA Approves Bayer's New Drug Application for KERENDIA®
2024-02-06 U.S. Reissue Patent No. RE49,826 Issues
2025-09-09 Macleods Sends Paragraph IV Notice Letter to Bayer
2025-09-12 Bayer Receives Paragraph IV Notice Letter
2025-10-20 Complaint for Patent Infringement Filed

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"

  • Issued: February 6, 2024

The Invention Explained

  • Problem Addressed: The patent’s background section states that prior "research scale synthesis" methods for producing the active pharmaceutical ingredient finerenone are "unsuitable for a further large-scale process" ('826 Patent, col. 2:49-51). These earlier methods allegedly suffered from low overall yield, required many laborious chromatographic purifications, used very high dilutions, and involved high excesses of reagents, making them inefficient and costly for industrial production ('826 Patent, col. 2:51-59).
  • The Patented Solution: The patent discloses what it describes as a "novel and improved process" that affords the compound in a reproducible manner with high overall yield, low production costs, and high purity suitable for regulatory submission and commercial manufacturing ('826 Patent, col. 1:16-20; col. 2:60-67). The invention includes specific process steps for synthesis and purification that result in a defined, stable crystalline form of the final compound, designated "polymorph I" ('826 Patent, col. 13:22-24).
  • Technical Importance: Developing an industrially practicable synthesis is a critical step in transforming a laboratory-scale chemical compound into a commercially viable pharmaceutical product available to patients ('826 Patent, col. 2:60-67).

Key Claims at a Glance

  • The complaint alleges infringement of one or more claims of the RE’826 Patent, and refers to Defendant’s challenge to claims 14-30 (Compl. ¶41, ¶51). The first independent claim in this range is Claim 14.
  • Independent Claim 14:
    • A compound of the formula (I)
    • in crystalline form of polymorph I
    • wherein the x-ray diffractogram of the compound exhibits peak maxima of the 2 theta angle at 8.5, 14.1, and 19.0.
  • The complaint reserves the right to assert other claims, which could include dependent product claims further defining the polymorph's characteristics or process claims for its manufacture.

III. The Accused Instrumentality

Product Identification

  • The accused instrumentality is "Macleods's ANDA Product," a proposed generic version of Bayer's KERENDIA® (finerenone) tablets, identified in connection with ANDA No. 220747 (Compl. ¶1, ¶14).

Functionality and Market Context

  • The accused product contains finerenone, a non-steroidal mineralocorticoid receptor antagonist (nsMRA) (Compl. ¶30). It is indicated for reducing the risk of kidney disease decline, cardiovascular events, and hospitalization for heart failure in certain adult patients (Compl. ¶30).
  • The complaint alleges that Macleods seeks FDA approval to market its generic finerenone tablets in 10 mg and 20 mg dosages before the expiration of the RE’826 Patent, which is listed in the FDA's Orange Book as covering KERENDIA® (Compl. ¶32, ¶39).

IV. Analysis of Infringement Allegations

The complaint does not provide sufficient detail for analysis of how specific features of the accused ANDA product map to the elements of the asserted patent claims. The infringement allegation is statutory, based on the act of filing an ANDA under 35 U.S.C. § 271(e)(2)(A), which seeks approval to market a drug claimed in a patent before that patent's expiration (Compl. ¶49). The substantive basis for infringement is the allegation that the product Macleods intends to market upon approval will meet the limitations of one or more claims of the RE’826 Patent (Compl. ¶51).

No probative visual evidence provided in complaint.

Identified Points of Contention

  • Scope Questions: A principal question will be whether the generic finerenone product described in Macleods's ANDA possesses the specific crystalline structure of "polymorph I" as defined by the analytical data (e.g., X-ray diffraction peaks) recited in independent claim 14 and its dependent claims.
  • Technical Questions: Based on the allegations in Macleods's Paragraph IV letter, a key dispute will be whether the claimed polymorph is non-obvious and enabled by the prior art (Compl. ¶41). The litigation will likely involve extensive expert testimony and competing analytical data regarding the crystalline structure of the active ingredient in Macleods's proposed generic product.

V. Key Claim Terms for Construction

  • The Term: "crystalline form of polymorph I"
  • Context and Importance: This term is the central limitation of independent product claim 14 and its related dependent claims. The entire infringement analysis for these claims will depend on whether the defendant's product embodies this specific solid-state form of finerenone. Practitioners may focus on this term because disputes over pharmaceutical polymorphs are common in ANDA litigation and often determine the outcome of the case.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The patent does not appear to provide language supporting a broad interpretation; the definition is tied to specific, quantitative measurements. A party might argue that minor variations in analytical data still fall within the scope of the term, but this would be an argument about the scope of the claim, not the meaning of the term itself.
    • Evidence for a Narrower Interpretation: The patent provides a highly specific and narrow definition of "polymorph I." Claim 14 explicitly defines it by reference to an x-ray diffractogram with peak maxima at specific angles ('826 Patent, cl. 14). Dependent claims add further defining characteristics, including additional x-ray peaks, specific band maxima in IR and Raman spectra, and a melting point of 252° C. ('826 Patent, cls. 15-18). This extensive, data-driven definition in the specification and claims may be cited to argue that only a product matching these exact physical properties can be considered "polymorph I."

VI. Other Allegations

  • Indirect Infringement: The complaint alleges that if Macleods's ANDA is approved, Macleods will actively induce infringement by encouraging healthcare professionals and patients to use the generic product in an infringing manner, and will contribute to infringement by selling a product whose use infringes the patent (Compl. ¶45, ¶52, ¶60).
  • Willful Infringement: The complaint alleges that Macleods acted with full knowledge of the RE’826 Patent and "without a reasonable basis for believing" that its generic product would not infringe (Compl. ¶53). This allegation appears to be based on Macleods's filing of a Paragraph IV certification, which requires a statement regarding a patent listed in the FDA's Orange Book.

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

  • A core issue will be one of "polymorphic identity": does the crystalline structure of the generic finerenone described in Macleods's confidential ANDA submission meet the specific X-ray diffraction, spectroscopic, and thermal analysis data required by the definition of "polymorph I" in the asserted claims of the RE’826 Patent?
  • A central validity question will be one of "obviousness": as raised in Defendant's Paragraph IV letter, was the isolation of this specific, stable "polymorph I" an obvious outcome for a person of ordinary skill in the art attempting to scale up the synthesis of finerenone, or does it represent a non-obvious inventive step?
  • A key evidentiary question will be one of "technical proof": what will competing analyses of the respective products show, and can Plaintiff prove, by a preponderance of the evidence, that the product Macleods will sell upon approval is the same crystalline form as that claimed in the RE’826 Patent?