DCT

1:23-cv-00448

AbbVie Inc v. Hetero Labs Ltd

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Key Events
Complaint

I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 1:23-cv-00448, D. Del., 04/24/2023
  • Venue Allegations: Venue is alleged to be proper in the District of Delaware because Defendant Hetero USA Inc. is incorporated in Delaware, and the foreign defendants, Hetero Labs Limited and Hetero Labs Limited Unit-V, may be sued in any judicial district.
  • Core Dispute: Plaintiff alleges that Defendants' submission of an Abbreviated New Drug Application (ANDA) to market a generic version of the drug ORILISSA® constitutes an act of infringement of a patent covering specific compositions of the active ingredient, elagolix sodium.
  • Technical Context: The technology relates to pharmaceutical compositions of elagolix sodium, a gonadotropin-releasing hormone (GnRH) receptor antagonist used for the management of pain associated with endometriosis.
  • Key Procedural History: This action follows a prior lawsuit filed on October 27, 2022, against the same defendants and the same ANDA, but asserting a different set of patents. This complaint was filed in response to a new notice letter regarding the recently issued patent-in-suit.

Case Timeline

Date Event
2018-07-23 '239 Patent Priority Date
2018-07-23 FDA approved NDA for ORILISSA®
2022-09-12 Hetero's First Notice Letter for other patents
2022-10-27 AbbVie filed "First Suit" against Hetero
2023-01-03 U.S. Patent No. 11,542,239 Issued
2023-03-10 Hetero's Second Notice Letter for the '239 Patent
2023-04-24 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.

The Invention Explained

  • Problem Addressed: The patent’s background section states that since the active substance elagolix sodium is generally amorphous, its purification can be more complex than for substances with stable polymorphic forms. It notes that a commercially available drug must have a very low impurity profile and be manufactured in a reproducible, cost-effective, and safe manner. (’239 Patent, col. 2:46-54).
  • The Patented Solution: The invention addresses this problem by defining highly purified compositions of elagolix sodium (referred to as Compound (I)) with specific, low-level limits on certain impurities. The patent also discloses processes to achieve this purity, including the creation of a novel crystalline salicylate salt intermediate (Compound (II)), which allows for more efficient purification and improved manufacturability before being converted to the final active substance. (’239 Patent, Abstract; col. 14:27-40).
  • Technical Importance: Establishing reliable, large-scale manufacturing processes that consistently produce a drug substance meeting stringent regulatory standards for purity is critical for both patient safety and the commercial viability of a pharmaceutical product. (’239 Patent, col. 2:55-62).

Key Claims at a Glance

  • The complaint asserts infringement of "one or more claims" of the ’239 Patent without specifying them (Compl. ¶2). Independent claim 1 is representative of the asserted composition claims.
  • Independent Claim 1 requires:
    • A composition comprising: Compound (I) (elagolix sodium).
    • The composition also comprises one or more impurities selected from a specific group of five chemical structures identified as (iii), (v), (vi), (vii), and (viii).
    • The amount of Compound (I) comprises at least 97 weight percent of the composition.
    • The amount of the one or more impurities is greater than zero and equal to or less than 3 weight percent of the composition.
  • The complaint does not explicitly reserve the right to assert other independent or dependent claims, though such an action is common practice.

III. The Accused Instrumentality

Product Identification

  • The accused instrumentality is "Hetero's Generic Product," defined as generic elagolix sodium oral tablets (in 150 mg and 200 mg base equivalent dosages) for which Hetero seeks FDA approval via Abbreviated New Drug Application (ANDA) No. 217690 (Compl. ¶¶1-2).

Functionality and Market Context

  • The accused product is a generic version of AbbVie's ORILISSA® tablets (Compl. ¶1). It is intended to function as a GnRH receptor antagonist for managing moderate to severe pain from endometriosis (Compl. ¶¶5, 7). The complaint alleges that Hetero has represented to the FDA that its generic product is "pharmaceutically and therapeutically equivalent" to ORILISSA® (Compl. ¶63). The branded drug, ORILISSA®, has been prescribed to over 80,000 women (Compl. ¶5).

No probative visual evidence provided in complaint.

IV. Analysis of Infringement Allegations

The complaint does not contain a detailed claim chart. The infringement allegations are based on the statutory act of infringement under the Hatch-Waxman Act, where the submission of an ANDA for a generic drug is itself the infringing act if the eventual marketing of that drug would infringe a valid patent. The following chart summarizes the infringement theory as inferred from the complaint's allegations.

U.S. Patent No. 11,542,239 Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
A composition comprising: Compound (I), Hetero's Generic Product is an elagolix sodium oral tablet, and the complaint alleges it contains Compound (I) as its active ingredient. ¶¶1, 51, 63 col. 2:1-12
and one or more impurity selected from a group consisting of: (iii), (v), (vi), (vii), and (viii) The complaint alleges that Hetero's Generic Product infringes the '239 patent, which requires the presence of certain impurities. Direct evidence of the specific impurity profile is not provided. ¶¶62, 64 col. 91:23-45
wherein Compound (I) comprises at least 97 weight percent of the composition The complaint alleges Hetero’s product is therapeutically equivalent to ORILISSA®, which is covered by the ’239 patent, implying it meets the claimed purity levels. ¶¶63, 64 col. 92:46-49
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. As with the purity level, the allegation of therapeutic equivalence suggests the impurity levels in Hetero's product will fall within the claimed ranges. ¶¶63, 64 col. 92:46-49

Identified Points of Contention

  • Factual Question: The central dispute will be factual: does the composition of Hetero’s proposed generic product, as detailed in its confidential ANDA submission, meet every limitation of an asserted claim? Discovery will focus on identifying the precise purity and impurity profile of Hetero's product to determine if it contains at least 97% Compound (I) and one or more of the specific, recited impurities in the claimed 0-3% range.
  • Validity Question: Hetero has certified that the patent is invalid (Compl. ¶56). A likely defense will be that the claimed composition is obvious under 35 U.S.C. § 103. Hetero may argue that achieving the claimed purity levels and impurity profile was merely the result of routine optimization and purification techniques known to a person of ordinary skill in the art seeking to produce a pharmaceutical-grade version of a known compound.

V. Key Claim Terms for Construction

  • The Term: "at least about 97 weight percent"
  • Context and Importance: This term is critical because it defines the lower boundary of purity for the active ingredient, which is a central feature of the claimed composition. The scope of the word "about" will be a key issue in determining infringement, as it dictates how much deviation, if any, is permissible from the strict 97% value. Practitioners may focus on this term because infringement could turn on whether Hetero's product, if found to be slightly below 97% pure (e.g., 96.9%), is still captured by the claim.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The patent uses the word "about" numerous times throughout the specification in relation to compositions and processes, suggesting the inventors intended it to have a meaning of approximation rather than being superfluous. (’239 Patent, col. 2:18, col. 2:21, col. 5:60, et al.).
    • Evidence for a Narrower Interpretation: The claims themselves recite specific numerical ranges (e.g., claim 1 recites ">0 and <=3%"). Furthermore, the specification provides numerous examples with precise measurements. A party could argue that the scope of "about" should be constrained by the degree of precision and variation demonstrated in the patent's own working examples or what is standard in the relevant art for such measurements.

VI. Other Allegations

  • Indirect Infringement: The complaint alleges active inducement of infringement under 35 U.S.C. § 271(b) (Compl. ¶65). The factual basis is the allegation that Hetero knows and intends for healthcare providers to prescribe, and patients to use, its generic product according to the instructions in its proposed package insert, which would constitute direct infringement (Compl. ¶¶66-68).
  • Willful Infringement: The complaint does not use the word "willful," but it requests a finding that the case is "exceptional" and seeks attorney fees under 35 U.S.C. § 285, a remedy often tied to findings of willfulness or litigation misconduct (Compl. ¶G, p. 16). The complaint alleges that Hetero has had knowledge of the '239 patent at least since its notice letter dated March 10, 2023 (Compl. ¶69).

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

The resolution of this case will likely depend on the answers to three central questions:

  1. A core evidentiary question of composition: Does the product defined in Hetero's confidential ANDA actually contain elagolix sodium and one or more of the specific impurities listed in Claim 1, all within the precise weight-percent ranges required by the patent?
  2. A central validity question of obviousness: Is a composition of elagolix sodium having the claimed purity and impurity profile non-obvious, or was achieving this profile a predictable result of routine optimization for a skilled pharmaceutical chemist developing a known drug for commercial sale?
  3. A claim construction question of scope: What is the legally operative meaning of the term "about" as it modifies the numerical purity limitations, and will that meaning be broad enough to read on the measured purity of Hetero’s product?