DCT

1:25-cv-00380

Sumitomo Pharma Switzerland GmbH v. Annora Pharma Pvt Ltd

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I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 1:25-cv-00380, D. Del., 03/27/2025
  • Venue Allegations: Venue is alleged to be proper as to the foreign defendants, Annora Pharma and Hetero Labs, because they may be sued in any judicial district. Venue is alleged to be proper as to the domestic defendants, Hetero USA and Camber Pharmaceuticals, because both are corporations organized under the laws of Delaware.
  • Core Dispute: Plaintiffs allege that Defendants' submission of an Abbreviated New Drug Application (ANDA) to the FDA for approval to market a generic version of the drug Myfembree® constitutes an act of infringement of four U.S. patents.
  • Technical Context: The technology concerns a combination drug therapy for treating hormone-sensitive gynecological conditions, such as uterine fibroids and endometriosis, by pairing a hormone suppressor with an "add-back" hormone replacement to manage side effects.
  • Key Procedural History: This action was initiated under the Hatch-Waxman Act following Defendants' submission of ANDA No. 220123 to the FDA. On February 14, 2025, Defendants provided Plaintiffs with a Paragraph IV Notice Letter, asserting that the patents-in-suit are invalid or will not be infringed by the proposed generic product.

Case Timeline

Date Event
2012-09-28 Earliest Priority Date for ’178 Patent
2016-09-30 Earliest Priority Date for ’551, ’684, and ’812 Patents
2021-05-26 FDA Approval of Myfembree® New Drug Application (NDA)
2021-06-15 ’551 Patent Issued
2023-10-24 ’178 Patent Issued
2023-10-24 ’812 Patent Issued
2024-04-16 ’684 Patent Issued
2025-02-14 Defendants' Paragraph IV Notice Letter Sent to Plaintiffs
2025-03-27 Complaint Filed

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

No probative visual evidence provided in complaint.

U.S. Patent No. 11,795,178 - Compositions of Thienopyrimidine Derivatives

(Issued Oct. 24, 2023)

The Invention Explained

  • Problem Addressed: The complaint does not provide sufficient detail for analysis of the problem addressed by this patent. Based on the patent title, the problem likely relates to the physical properties of the active pharmaceutical ingredient.
  • The Patented Solution: The complaint alleges infringement of claims directed to compositions of thienopyrimidine derivatives (Compl. ¶36). The active ingredient relugolix is a thienopyrimidine derivative. Such patents typically claim specific crystalline forms of a compound that offer advantages in stability, purity, or manufacturing consistency over other forms.
  • Technical Importance: The crystalline form of an active pharmaceutical ingredient can be critical for ensuring consistent bioavailability, shelf life, and manufacturability of a final drug product (Compl. ¶36).

Key Claims at a Glance

  • The complaint asserts independent claim 1 and dependent claims 25-28 (Compl. ¶49).
  • The complaint does not provide sufficient detail for analysis of the claim elements.

U.S. Patent No. 11,033,551 - Methods of Treating Uterine Fibroids

(Issued June 15, 2021)

The Invention Explained

  • Problem Addressed: The patent's background describes the challenge of treating hormone-sensitive conditions like uterine fibroids. While GnRH antagonists can be effective by suppressing estrogen, this suppression can lead to serious side effects like bone mineral density loss, limiting the duration of treatment (’551 Patent, col. 2:7-19).
  • The Patented Solution: The invention proposes a combination "add-back" therapy. It involves administering a highly suppressive dose of a GnRH antagonist (relugolix) to reduce disease symptoms, while simultaneously co-administering a hormone replacement medicament (an estrogen and a progestin). This add-back therapy is designed to mitigate the side effects of estrogen suppression, allowing for safer long-term treatment (’551 Patent, col. 4:2-20, Abstract).
  • Technical Importance: This approach allows for the long-term use of a potent oral GnRH antagonist, offering a non-surgical therapeutic option for chronic conditions that avoids the "flare" effect and depot-injection drawbacks of older GnRH agonist treatments (’551 Patent, col. 3:5-24, 4:32-51).

Key Claims at a Glance

  • The complaint asserts independent claims 1 and 25, as well as several dependent claims (Compl. ¶59).
  • Essential Elements of Independent Claim 1:
    • A method for treating uterine fibroids in a pre-menopausal woman in need thereof.
    • The method comprises orally administering once-daily a combination.
    • The combination includes:
      • about 40 mg of relugolix or a pharmaceutically acceptable salt thereof;
      • about 1.0 mg of estradiol; and
      • about 0.5 mg of norethindrone acetate.
    • Wherein the woman's ovarian estrogen production is suppressed, as demonstrated by prevention of ovulation.
    • Wherein the woman's pre-menopausal bone mineral density during treatment is within ±3% of her pre-menopausal bone mineral density prior to treatment.

U.S. Patent No. 11,957,684 - Treatment of Heavy Menstrual Bleeding Associated with Uterine Fibroids

(Issued Apr. 16, 2024)

Technology Synopsis

This patent is directed to methods of using the combination therapy of relugolix, estradiol, and norethindrone acetate to specifically treat heavy menstrual bleeding associated with uterine fibroids. The technical approach is the same "add-back" therapy described for the ’551 Patent, aiming to provide symptomatic relief while mitigating side effects like bone density loss. (Compl. ¶38).

Asserted Claims

Claims 1-5, 7, 11, 16, and 20-22 are asserted (Compl. ¶69). Independent claim 1 is a method claim for treating this condition.

Accused Features

Defendants' ANDA product, a generic version of Myfembree®, is accused of infringing because its intended use and proposed labeling will allegedly instruct users to perform the patented method (Compl. ¶¶ 69, 72).

U.S. Patent No. 11,793,812 - Methods of Treating Endometriosis

(Issued Oct. 24, 2023)

Technology Synopsis

This patent covers methods of using the same relugolix combination therapy to treat endometriosis. The patent's background describes the debilitating pain associated with endometriosis and the challenge of using hormone-suppressing agents long-term due to side effects (’812 Patent, col. 1:53-2:65). The invention provides the "add-back" therapy as a solution for this specific indication. (Compl. ¶39).

Asserted Claims

Claims 1 and 4 are asserted (Compl. ¶79). Both are independent method claims.

Accused Features

Defendants' ANDA product is accused of infringing because its FDA-approved uses include the management of pain associated with endometriosis, and its proposed labeling will allegedly instruct users to practice the patented methods (Compl. ¶¶ 34, 79, 82).

III. The Accused Instrumentality

Product Identification

The accused instrumentality is Defendants' "ANDA Product," an Abbreviated New Drug Application (ANDA) No. 220123 seeking FDA approval to market a generic version of Myfembree® (Compl. ¶1).

Functionality and Market Context

The ANDA Product is a tablet for oral administration containing 40 mg of relugolix, 1 mg of estradiol, and 0.5 mg of norethindrone acetate (Compl. ¶1, ¶42). By submitting the ANDA, Defendants have represented to the FDA that their product has the same active ingredients, dosage form, strength, and is bioequivalent to the branded drug Myfembree® (Compl. ¶43). Myfembree® is approved for managing heavy menstrual bleeding associated with uterine fibroids and moderate to severe pain associated with endometriosis in premenopausal women (Compl. ¶34). The filing of the ANDA itself, seeking approval prior to the expiration of patents listed in the FDA's Orange Book, constitutes the act of infringement under 35 U.S.C. § 271(e)(2) (Compl. ¶¶ 1, 35, 49).

IV. Analysis of Infringement Allegations

The complaint does not provide element-by-element infringement allegations or reference a claim chart. The infringement theory for the composition patent (’178 Patent) is that Defendants' manufacture and sale of a product containing the relugolix active ingredient will directly infringe claims to a specific crystalline form of that compound (Compl. ¶50). For the method patents (’551, ’684, and ’812 Patents), the primary theory is induced infringement, where Defendants' proposed product labeling will allegedly instruct healthcare providers and patients to administer the ANDA Product in a manner that practices the steps of the claimed therapeutic methods (Compl. ¶¶ 62, 72, 82).

  • Identified Points of Contention:
    • Physical Identity Question (’178 Patent): A central factual question will be whether the crystalline form of relugolix used in the ANDA Product is identical to the crystal form defined by the specific X-ray powder diffraction peaks recited in the asserted claims of the ’178 Patent.
    • Inducement Question (Method Patents): The analysis may turn on whether the Defendants' proposed label encourages, recommends, or promotes an infringing use. This raises the question of whether the label will contain instructions that satisfy every limitation of the asserted method claims, such as administration to a "pre-menopausal woman" for a specified duration to achieve a particular clinical outcome (e.g., suppression of ovarian estrogen production).

V. Key Claim Terms for Construction

  • The Term: "about" (as in "about 40 mg," "about 1.0 mg," "about 0.5 mg")
  • Context and Importance: This term appears in the dosage limitations of the independent method claims (e.g., ’551 Patent, Claim 1). The Defendants’ ANDA Product contains the exact dosages of 40 mg, 1.0 mg, and 0.5 mg (Compl. ¶42). The construction of "about" will be critical to determining the scope of these claims and whether they are limited to the precise recited amounts or encompass a range around them. Practitioners may focus on this term because its interpretation could determine whether minor manufacturing variations fall within the claim scope or whether the patentee is strictly limited to the dosages tested in clinical trials.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The specification of the ’551 Patent repeatedly uses ranges in its summary and detailed description, which may support a construction where "about" provides some numerical leeway. For example, the specification describes compositions comprising "about 10 mg to about 60 mg" of relugolix, "about 0.5 mg to about 2 mg of estradiol," and "about 0.01 mg to about 5 mg of a progestin" (’551 Patent, col. 4:10-17).
    • Evidence for a Narrower Interpretation: The patent claims specific dosages (40 mg, 1.0 mg, 0.5 mg) that directly correspond to the formulation of the commercial embodiment, Myfembree®. Parties may argue that the clinical data supporting the patent is tied to this specific formulation, suggesting "about" should be construed narrowly to mean approximately the recited value, accounting only for minor measurement or manufacturing tolerances. The Certificate of Correction for the ’551 Patent, which corrected claim 20 to precisely recite "about 1.0 mg of estradiol", may also be cited to argue for the importance of specific dosage amounts (’551 Patent, Certificate of Correction).

VI. Other Allegations

  • Indirect Infringement: The complaint alleges both induced and contributory infringement for all four patents-in-suit. The basis for induced infringement is the allegation that Defendants' marketing and proposed product labeling will intentionally encourage healthcare providers and patients to use the ANDA product in an infringing manner (Compl. ¶¶ 52, 62, 72, 82). The basis for contributory infringement is that the ANDA Product is a material part of the inventions, is especially adapted for an infringing use, and is not a staple article of commerce suitable for substantial noninfringing use (Compl. ¶¶ 53, 63, 73, 83).
  • Willful Infringement: The complaint does not use the term "willful," but for each count it alleges that the Defendants' infringement constitutes an "exceptional case" and that Defendants "acted, and upon FDA approval... will act, without a reasonable basis for believing that they would not be liable for directly and/or indirectly infringing" the patents (Compl. ¶¶ 56, 66, 76, 86). This language forms the basis for seeking enhanced damages and attorneys' fees, and is predicated on Defendants' pre-suit knowledge of the patents, evidenced by their Paragraph IV certification (Compl. ¶¶ 44-45).

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

  • A core issue will be one of evidentiary proof: for the composition patent (’178), can Plaintiffs demonstrate that the crystalline form of relugolix in the ANDA product is the same as the patented form? This will likely require detailed scientific analysis of the physical properties of the Defendants' active ingredient.
  • A second central issue will be one of induced infringement: for the method patents (’551, ’684, ’812), does the language of the Defendants' proposed product label actively instruct or encourage physicians and patients to perform every step of the claimed methods for the specified patient populations? The outcome may depend on the final FDA-approved labeling for the generic product.
  • A key legal question will be one of claim scope: how broadly will the court construe the term "about" when applied to the specific drug dosages in the asserted claims? This will determine whether the claims are limited to the exact formulation of the branded drug or if they encompass a broader range of potential formulations.