DCT

1:25-cv-00431

Hetero Labs Ltd v. AbbVie Inc

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I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 1:25-cv-00431, D. Del., 04/07/2025
  • Venue Allegations: Venue is alleged to be proper because the Defendants previously commenced a related patent infringement action against the Plaintiff in the same district.
  • Core Dispute: Plaintiff, a generic drug manufacturer, seeks a declaratory judgment that its proposed generic elagolix tablets will not infringe Defendants' U.S. Patent No. 12,102,637, and/or that the patent is invalid.
  • Technical Context: The technology relates to pharmaceutical formulations of elagolix, an orally administered gonadotropin-releasing hormone (GnRH) antagonist used to treat conditions such as endometriosis.
  • Key Procedural History: This action arises under the Hatch-Waxman Act following Plaintiff's filing of an Abbreviated New Drug Application (ANDA) with a Paragraph IV certification for a generic version of Defendants' drug, ORILISSA®. The complaint notes that Defendants initiated a prior, related litigation against Plaintiff and subsequently listed the patent-in-suit in the FDA's Orange Book, prompting this declaratory judgment action.

Case Timeline

Date Event
2017-08-18 Earliest Priority Date for ’637 Patent
2022-10-27 Defendants initiate "Related Litigation" against Plaintiff
2024-10-01 ’637 Patent Issues
2025-04-07 Complaint for Declaratory Judgment Filed

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

U.S. Patent No. 12,102,637 - Pharmaceutical Formulations For Treating Endometriosis, Uterine Fibroids, Polycystic Ovary Syndrome or Adenomyosis

The Invention Explained

  • Problem Addressed: The patent's background section describes two primary challenges in developing an oral tablet for its active pharmaceutical ingredient (API), referred to as "Compound A" (elagolix). First, the API has a tendency to form a gel when it comes in contact with water, which can limit its dissolution and lead to variable patient bioavailability (’637 Patent, col. 2:36-50). Second, the API can degrade into an undesirable "lactam-containing degradation product," referred to as "Compound B," which presents safety and efficacy concerns (’637 Patent, col. 2:50-59).
  • The Patented Solution: The invention is a pharmaceutical composition that combines the API with at least one "anti-gelling agent," such as sodium carbonate (’637 Patent, col. 2:62-63). This agent is disclosed to serve a dual purpose: it facilitates the release of the API by preventing gelling, and it also acts as a stabilizer by creating a microenvironment that reduces the formation of the degradation product, Compound B (’637 Patent, col. 3:5-12). The patent also discloses specific formulation processes, such as roller compaction, to manufacture the composition (e.g., ’637 Patent, FIG. 1).
  • Technical Importance: This formulation technology enables the creation of a stable, orally bioavailable solid dosage form for a nonpeptide GnRH antagonist, providing a convenient treatment option for hormone-dependent conditions that might otherwise require more invasive or less convenient administration routes (’637 Patent, col. 2:17-26).

Key Claims at a Glance

  • The complaint seeks a declaratory judgment regarding "any valid claim" of the patent and does not single out specific claims for analysis (Compl. ¶30). The analysis below focuses on the first independent claim as a representative example.
  • Independent Claim 1: The key elements are:
    • A pharmaceutical composition in the form of a stable immediate release tablet;
    • Comprising "elagolix sodium" in an amount from about 20% to about 60% by weight;
    • Comprising "sodium carbonate" in an amount from about 10% to about 30% by weight; and
    • Comprising a specific combination of two fillers: a "first filler" (mannitol) from about 20% to about 50% by weight, and a "second filler" (pregelatinized starch) from about 1% to about 20% by weight.
  • The complaint's broad request for relief implies that dependent claims are also at issue (Compl., Prayer for Relief ¶b).

III. The Accused Instrumentality

Product Identification

  • "Hetero's ANDA Product," identified as "elagolix oral tablets, 150 mg and 200 mg" (Compl. ¶26).

Functionality and Market Context

  • The product is a proposed generic version of Defendants' branded drug ORILISSA®, for which Plaintiff is seeking FDA approval via ANDA No. 217690 (Compl. ¶26-27). As a declaratory judgment action filed by the ANDA applicant, the complaint does not provide specific details regarding the formulation, excipients, or manufacturing process of the accused product beyond its identification as an elagolix sodium tablet. The justiciable controversy is based on Plaintiff's Paragraph IV certification asserting that its product will not infringe any valid claim of the ’637 patent (Compl. ¶27, ¶31).

IV. Analysis of Infringement Allegations

The complaint seeks a declaratory judgment of non-infringement and does not contain affirmative infringement allegations or a claim chart. The analysis of potential disputes is therefore based on the patent's claims and the context of ANDA litigation.

No probative visual evidence provided in complaint.

Identified Points of Contention

  • Formulation Match: The primary question for literal infringement will be whether Plaintiff's confidential ANDA formulation contains the specific excipients recited in Claim 1—"sodium carbonate," "mannitol," and "pregelatinized starch"—at the claimed weight percentages. As this is an ANDA case, the dispute will turn on the precise contents of Plaintiff's proposed product.
  • Scope Questions: The use of "about" in the claimed weight percentage ranges for each component raises the question of how much deviation from the recited values is permissible for literal infringement. If Plaintiff's formulation falls outside the literal scope, a central issue will be whether it infringes under the doctrine of equivalents. For example, does an alternative filler in Plaintiff's product perform substantially the same function in substantially the same way to achieve the same result as the claimed "mannitol" and "pregelatinized starch" combination?
  • Functional Questions: A key question for infringement, particularly under the doctrine of equivalents, may be whether Plaintiff's formulation achieves the "stable immediate release" properties described in the patent. This will involve comparing the dissolution and degradation profiles of Plaintiff's product with the performance metrics disclosed in the ’637 patent.

V. Key Claim Terms for Construction

"stable immediate release tablet"

  • Context and Importance: This term appears in Claim 1 and is central to defining the invention's scope. The patent heavily emphasizes solving the dual problems of API degradation and gelling (’637 Patent, col. 2:36-59). Practitioners may focus on this term because its construction will determine whether specific functional characteristics—related to both chemical stability and dissolution rate—are required limitations of the claim.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: A party seeking a broader construction may argue that "stable" and "immediate release" are general terms of art in pharmaceuticals, not tied to any specific numerical threshold unless explicitly recited. They might argue these terms simply describe the general character of the tablet without importing specific stability or dissolution data from the specification into the claims.
    • Evidence for a Narrower Interpretation: A party seeking a narrower construction will likely point to the specification's detailed discussion of what makes the formulation successful. This includes specific data on minimizing the formation of the "Compound B" degradant (e.g., ’637 Patent, Table 16, col. 49-50) and achieving rapid dissolution (e.g., "at least 80% of Compound A... in about 30 minutes") (’637 Patent, col. 20:15-20). They may argue these disclosed objectives should inform the meaning of "stable" and "immediate release," thereby narrowing the claim's scope to formulations that meet these performance criteria.

"sodium carbonate"

  • Context and Importance: This is a key ingredient recited in Claim 1. The patent specification describes it not only as a component but as an "anti-gelling agent" that also functions as a "stabilizer" (’637 Patent, col. 3:5-12). Practitioners may focus on this term because the dispute could center on whether an alternative basic salt used by the accused product is an equivalent.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation (Doctrine of Equivalents): The specification identifies a broad class of "anti-gelling agents," including other alkali metal salts, bases, and basic amino acids, that could solve the gelling problem (’637 Patent, col. 3:13-28). A party could argue that this disclosure suggests other basic compounds could be functional equivalents to "sodium carbonate" for the purposes of the invention.
    • Evidence for a Narrower Interpretation: The patent's examples and data focus specifically on the performance of sodium carbonate (e.g., ’637 Patent, FIG. 8, Table 1). A party could argue that the disclosed invention is not just about using any anti-gelling agent, but about the specific, surprising discovery that sodium carbonate uniquely provides both anti-gelling and stabilizing properties, potentially limiting the scope of equivalents.

VI. Other Allegations

Indirect Infringement

  • The complaint requests a declaration that Plaintiff would not be liable for indirect infringement if its product were marketed (Compl., Prayer for Relief ¶b). As a forward-looking request in a declaratory judgment action, the complaint does not allege specific facts concerning inducement or contributory infringement but seeks to resolve liability before any potential commercial launch.

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

  • A central factual question will be one of compositional identity: does the Plaintiff's proposed generic formulation, as confidentially disclosed in its ANDA, contain the specific combination of elagolix sodium, sodium carbonate, mannitol, and pregelatinized starch within the weight-percentage ranges recited in Claim 1 of the ’637 patent?
  • A key legal question will be one of claim scope and equivalence: if the Plaintiff's formulation does not literally infringe, does its use of any alternative excipients or different concentrations fall within the scope of the claims under the doctrine of equivalents, particularly concerning the meaning of "about" and the dual functions of the claimed "sodium carbonate"?
  • A critical validity question will be one of obviousness: given the known problems of gelling and degradation associated with elagolix, would the specific combination of commonly used pharmaceutical excipients at the claimed concentrations have been obvious to a person of ordinary skill in the art seeking to create a stable, oral tablet formulation?