DCT

1:23-cv-00892

AbbVie Inc v. Zenara Pharma Pvt Ltd

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Key Events
Complaint

I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 1:23-cv-00892, D. Del., 08/11/2023
  • Venue Allegations: Venue is alleged to be proper because the defendants are organized under the laws of India and may be sued in any judicial district in the United States.
  • Core Dispute: Plaintiff alleges that Defendants' submission of an Abbreviated New Drug Application (ANDA) for a generic version of the endometriosis drug ORILISSA® constitutes an act of infringement of a patent covering specific compositions of elagolix sodium.
  • Technical Context: The technology relates to highly purified pharmaceutical compositions of elagolix sodium, a gonadotropin-releasing hormone (GnRH) receptor antagonist used to manage moderate to severe pain associated with endometriosis.
  • Key Procedural History: This lawsuit was filed under the Hatch-Waxman Act, triggered by Defendants' Paragraph IV certification notice alleging that the patent-in-suit is invalid, unenforceable, or would not be infringed by their proposed generic product. The complaint was filed within the 45-day statutory window following receipt of the notice, which imposes an automatic 30-month stay on the FDA’s approval of the defendants' ANDA. The complaint also references a "First Suit" filed in 2022 concerning different patents related to the same ANDA.

Case Timeline

Date Event
2018-07-23 '239 Patent Priority Date
2018-07-23 FDA approves ORILISSA® New Drug Application (NDA)
2022-09-28 Zenara sends First Notice Letter (regarding other patents)
2022-10-27 AbbVie files "First Suit" against Zenara
2023-01-03 U.S. Patent No. 11,542,239 issues
2023-06-28 Zenara sends Second Notice Letter (regarding '239 patent)
2023-08-11 Complaint Filed

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

U.S. Patent No. 11,542,239 - "ELAGOLIX SODIUM COMPOSITIONS AND PROCESSES"

  • Patent Identification: U.S. Patent No. 11,542,239, "ELAGOLIX SODIUM COMPOSITIONS AND PROCESSES," issued January 3, 2023. (Compl. ¶46; ’239 Patent, p. 1).

The Invention Explained

  • Problem Addressed: The patent’s background section explains that active pharmaceutical ingredients must meet high purity standards for commercialization. It notes that since elagolix sodium is "generally amorphous," its purification can be "more complex" than for substances with well-defined polymorphic (crystalline) forms, making it difficult to achieve a "substantially pure active substance" suitable for large-scale manufacturing. (’239 Patent, col. 2:46-58).
  • The Patented Solution: The invention provides for compositions of elagolix sodium (referred to as Compound (I)) that are highly pure, specifically claiming compositions containing at least 97% elagolix sodium by weight and defining upper limits for the presence of specific, structurally identified impurities. (’239 Patent, Abstract; col. 2:16-24). The patent also details processes and novel intermediates that enable the production of this high-purity substance, improving its manufacturability. (’239 Patent, col. 13:1-col. 14:41).
  • Technical Importance: This technology is directed at solving a key problem in pharmaceutical manufacturing: ensuring a drug product can be produced consistently, cost-effectively, and with a very low impurity profile that satisfies stringent regulatory standards. (’239 Patent, col. 2:46-52).

Key Claims at a Glance

  • The complaint asserts infringement of "at least one claim" of the patent. The broadest independent composition claim, Claim 1, is representative of the core invention.
  • Independent Claim 1 requires:
    • A composition comprising: Compound (I) (the chemical structure for elagolix sodium)
    • and one or more impurity selected from a group consisting of: Compound (iii), Compound (v), Compound (vi), and Compound (vii) (all defined by specific chemical structures)
    • wherein Compound (I) comprises at least 97 weight percent of the composition
    • and wherein the one or more impurity is present in an amount that is greater than zero and equal to or less than 3 weight percent of the composition. (’239 Patent, col. 91:1-col. 92:44).
  • The complaint does not specify any dependent claims but reserves the right to assert them. (Compl. ¶59).

III. The Accused Instrumentality

Product Identification

  • The accused instrumentality is "Zenara's Generic Product," a proposed generic version of ORILISSA® oral tablets, which is the subject of ANDA No. 217760. (Compl. ¶1, ¶49).

Functionality and Market Context

  • The accused product is an oral tablet containing elagolix sodium as its active pharmaceutical ingredient, intended for the management of moderate to severe pain associated with endometriosis. (Compl. ¶45, ¶49).
  • The complaint alleges that Zenara has represented to the FDA that its generic product is "pharmaceutically and therapeutically equivalent" to AbbVie's ORILISSA® product. (Compl. ¶57). This allegation is central to the infringement theory, as it suggests the generic product will have the same chemical characteristics as the branded drug.
  • The complaint asserts that over 80,000 women have been prescribed ORILISSA®, indicating its market significance. (Compl. ¶5).

No probative visual evidence provided in complaint.

IV. Analysis of Infringement Allegations

The infringement allegation is statutory, arising from the submission of the ANDA, which is considered an act of infringement under 35 U.S.C. § 271(e)(2)(A). (Compl. ¶58). The complaint does not provide a claim chart, but the infringement theory rests on the allegation that Zenara’s product is equivalent to ORILISSA® and will therefore meet the limitations of the ’239 Patent's claims.

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
A composition comprising: Compound (I), and one or more impurity selected from a group consisting of: (iii), (v), (vi), and (vii) Zenara's Generic Product is an elagolix sodium oral tablet represented to the FDA as pharmaceutically and therapeutically equivalent to ORILISSA®. The complaint's infringement theory implies that this equivalence means the product necessarily contains the recited impurities. ¶49, ¶57, ¶58 col. 91:1-col. 92:44
wherein Compound (I) comprises at least 97 weight percent of the composition The complaint alleges that Zenara’s product is equivalent to ORILISSA®. The patent describes a "substantially pure active substance," which implies the high weight percentage of Compound (I) required by the claim. ¶57-¶58 col. 92:40-41
and wherein the one or more impurity is present in an amount that is greater than zero and equal to or less than 3 weight percent of the composition This limitation is also alleged to be met based on the representation of pharmaceutical equivalence to ORILISSA®, which the patent purports to cover. The complaint does not contain specific analytical data for Zenara's product. ¶57-¶58 col. 92:41-44
  • Identified Points of Contention:
    • Technical Question: A primary evidentiary issue will be whether Zenara's ANDA product actually contains the specific impurities recited in Claim 1 and whether its components fall within the claimed weight-percentage ranges. The case may turn on factual evidence from chemical analysis of Zenara's product, as the complaint relies on the inference of equivalence rather than direct measurement.

V. Key Claim Terms for Construction

  • The Term: "composition"
  • Context and Importance: The definition of "composition" is critical for applying the claim’s weight-percentage limitations. Practitioners may focus on this term because its scope determines the denominator for the purity calculation. If "composition" refers only to the active pharmaceutical ingredient (API) and its impurities, the calculation is straightforward. If it is construed to include the excipients in the final drug tablet, the weight percentages of the API and impurities would be vastly different, likely taking the accused product outside the claim scope.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The patent frequently references ORILISSA®, which is a final tablet formulation, and its FDA approval, suggesting the invention's relevance extends to the finished drug product. (’239 Patent, col. 2:39-41).
    • Evidence for a Narrower Interpretation: Claim 1 defines the "composition" as comprising Compound (I) and specified impurities, with weight percentages that total 100%. This strongly suggests the claim is directed to the purified API substance itself, prior to formulation with excipients. The specification’s repeated focus on purifying the "active substance" and improving its "manufacturability" supports this narrower reading. (’239 Patent, col. 2:53-58).

VI. Other Allegations

  • Indirect Infringement: The complaint alleges active inducement of infringement, stating that Zenara knows its product will be prescribed by healthcare professionals and used by patients for the approved indication. The proposed package insert is alleged to be an instruction to engage in infringing use. (Compl. ¶60-¶63).
  • Willful Infringement: While the complaint does not use the word "willful," it lays the foundation for such a claim by alleging that Zenara has had knowledge of the ’239 Patent since at least the date of its June 28, 2023 notice letter. (Compl. ¶63).

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

  • A central evidentiary question will be one of chemical identity: Does Zenara's proposed generic product, upon analysis, actually contain the specific combination of impurities recited in Claim 1, and do the components fall within the claimed weight-percentage limitations? The case will likely depend on whether the regulatory requirement of bioequivalence translates to a factual finding of literal infringement of the patent's composition claims.
  • A key claim construction issue will be the definitional scope of the term "composition." The court’s interpretation—whether it means the purified active ingredient alone or the final formulated tablet including excipients—will fundamentally alter the infringement analysis by defining the universe of materials to which the claim’s weight-percentage limitations apply.