DCT

1:25-cv-01493

Azurity Pharma Inc v. Annora Pharma Pvt Ltd

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Key Events
Complaint

I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 1:25-cv-01493, D. Del., 12/11/2025
  • Venue Allegations: Venue is asserted as proper under federal statute. Personal jurisdiction is alleged based on Defendant’s intent to market and sell its generic drug products in Delaware, as well as Defendant's previous participation in litigation within the district without contesting jurisdiction.
  • Core Dispute: Plaintiffs allege that Defendant’s filing of an Abbreviated New Drug Application (ANDA) for generic versions of the hypertension drug EDARBYCLOR® constitutes an act of infringement of patents related to pharmaceutical compositions and methods of treatment.
  • Technical Context: The dispute concerns pharmaceutical formulations for treating hypertension, a major market involving drugs that control blood pressure to reduce cardiovascular risk.
  • Key Procedural History: This is a Hatch-Waxman action initiated in response to a notification letter dated November 3, 2025, in which Defendant informed Plaintiffs it had submitted ANDA No. 220703 with a Paragraph IV certification, asserting that the patents-in-suit are invalid, unenforceable, or would not be infringed. The complaint was filed within the 45-day statutory window, triggering a potential 30-month stay of FDA approval for the generic product.

Case Timeline

Date Event
2007-03-28 Priority Date for U.S. Patent No. 9,066,936
2008-07-31 Priority Date for U.S. Patent No. 9,169,238
2008-12-23 Priority Date for U.S. Patent No. 9,387,249
2015-06-30 U.S. Patent No. 9,066,936 Issued
2015-10-27 U.S. Patent No. 9,169,238 Issued
2016-07-12 U.S. Patent No. 9,387,249 Issued
2025-11-03 Date of Defendant's ANDA Notice Letter
2025-12-11 Complaint Filing Date

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

U.S. Patent No. 9,066,936 - “Solid Pharmaceutical Composition Comprising a Benzimidazole-7-Carboxylate Derivative and a pH Control Agent”

The Invention Explained

  • Problem Addressed: The patent describes a technical challenge with a specific therapeutic compound for hypertension, azilsartan medoxomil. This compound is unstable in the neutral pH range where pharmaceutical tablets are typically produced, yet it has low solubility in the acidic pH range where it is stable (’936 Patent, col. 2:6-12). This makes it "extremely difficult to simultaneously afford the stability and solubility" required for an effective oral drug (’936 Patent, col. 2:12-15).
  • The Patented Solution: The invention introduces a "pH control agent" into the solid pharmaceutical composition. This agent is selected to create a low-pH microenvironment within the solid tablet itself, which stabilizes the active compound during manufacturing and storage. The agent is specifically defined as one that provides a pH of 3 to 5 when dissolved in water under specific test conditions (’936 Patent, col. 2:26-34, col. 21:2-3). This approach aims to achieve stability in the solid form while still permitting dissolution upon ingestion.
  • Technical Importance: The claimed solution provides a formulation strategy to create a viable, stable oral dosage form for a chemically sensitive active pharmaceutical ingredient.

Key Claims at a Glance

  • The complaint asserts infringement of one or more claims without specification (Compl. ¶ 31). Independent claim 1 is representative of the invention.
  • Essential Elements of Claim 1:
    • A solid pharmaceutical composition comprising a specific compound: (5-methyl-2-oxo-1,3-dioxol-4-yl)methyl 2-ethoxy-1-{[2'-(5-oxo-4,5-dihydro-1,2,4-oxadiazol-3-yl) biphenyl-4-yl]methyl}-1H-benzimidazole-7-carboxylate potassium salt.
    • The composition also comprises a solid pH control agent.
    • The pH control agent provides a pH of 3 to 5 when dissolved or suspended in water at a concentration of 1% w/v at 25° C. (’936 Patent, col. 21:1-col. 22:2).
  • The complaint does not explicitly reserve the right to assert dependent claims but makes a general allegation of infringement.

U.S. Patent No. 9,169,238 - “Solid Pharmaceutical Composition”

The Invention Explained

  • Problem Addressed: This patent addresses the difficulty of creating a combination drug product containing the same unstable compound (azilsartan medoxomil) along with a diuretic. A combination product "cannot be easily formulated into a preparation superior in stability and dissolution property since the chemical properties are different" for the two active ingredients (’238 Patent, col. 2:10-14).
  • The Patented Solution: The invention claims a solid preparation made via a specific manufacturing process. It requires a "first part" containing the azilsartan medoxomil and a pH control agent, and a "second part" containing the diuretic (chlorthalidone). Critically, the second part must be "obtained by granulating separately from the first part" (’238 Patent, col. 3:44-54). This physical separation of the granulated components before they are mixed and compressed into a final tablet is intended to prevent chemical interactions that could degrade either active ingredient.
  • Technical Importance: This process-defined structure allows two potentially incompatible active drugs to be co-formulated into a single, stable combination tablet.

Key Claims at a Glance

  • The complaint asserts infringement of one or more claims (Compl. ¶ 40). Independent claim 1 is representative.
  • Essential Elements of Claim 1:
    • A solid preparation comprising a first part and a second part.
    • The first part comprises the azilsartan medoxomil potassium salt and a pH control agent that provides a pH of 2 to 5 under specified conditions.
    • The second part comprises chlorthalidone.
    • The second part is "obtained by granulating separately from the first part." (’238 Patent, col. 19:50-col. 20:2).
  • The complaint makes a general allegation of infringement.

U.S. Patent No. 9,387,249 - “Methods of Treating Hypertension with at Least One Angiotensin II Receptor Blocker and Chlorthalidone”

The Invention Explained

  • Technology Synopsis: The patent addresses the therapeutic use of a combination of drugs to treat hypertension. It claims a method of treatment that comprises administering specific daily doses of an Angiotensin II receptor blocker (such as azilsartan medoxomil) and the diuretic chlorthalidone to a patient in need thereof (’249 Patent, Abstract; col. 3:41-48). The invention lies not in the composition itself, but in the method of using it for a therapeutic purpose.

Key Claims at a Glance

  • Asserted Claims: Independent claim 1 is asserted.
  • Accused Features: The complaint alleges that the proposed labeling for Defendant’s ANDA product will instruct physicians and patients to use the generic drug in a manner that directly infringes the claimed method, thereby inducing infringement (Compl. ¶¶ 49, 51).

III. The Accused Instrumentality

Product Identification

  • The accused instrumentalities are Defendant’s generic pharmaceutical products for which it seeks FDA approval under ANDA No. 220703 ("the ANDA Products") (Compl. ¶ 24).

Functionality and Market Context

  • The ANDA Products are identified as oral tablets containing 40 mg of azilsartan medoxomil and 12.5 mg of chlorthalidone, as well as tablets containing 40 mg of azilsartan medoxomil and 25 mg of chlorthalidone (Compl. ¶ 24).
  • The complaint alleges that these products contain the same active ingredients as Plaintiffs’ brand-name drug EDARBYCLOR® and will be sold with the same or substantially the same labeling (Compl. ¶ 25). The filing of the ANDA itself, seeking approval to market these products prior to the expiration of the patents-in-suit, constitutes the act of infringement under 35 U.S.C. § 271(e)(2) (Compl. ¶¶ 30, 39, 48).

No probative visual evidence provided in complaint.

IV. Analysis of Infringement Allegations

The complaint does not provide a claim chart or detailed element-by-element infringement allegations. The infringement theory is based on Defendant’s filing of ANDA No. 220703, which seeks approval to market a product with the same active ingredients and proposed labeling as Plaintiffs’ EDARBYCLOR® product (Compl. ¶¶ 24-25, 31, 40, 49).

The infringement allegations for the composition claims of the ’936 and ’238 Patents are premised on the assertion that the ANDA Products, if commercially manufactured as specified in the ANDA, will contain the claimed compositions (Compl. ¶¶ 31, 40). For the method claims of the ’249 Patent, the allegation is that Defendant’s proposed product labeling will instruct medical professionals and patients to administer the drug according to the claimed method, thus inducing infringement (Compl. ¶ 49).

  • Identified Points of Contention:
    • Technical Questions (’936 and ’238 Patents): A primary question will be whether the specific formulation detailed in Defendant's confidential ANDA filing meets the claim limitations. For the ’936 Patent, does the ANDA product's formulation contain excipients that qualify as a "solid pH control agent" providing a pH of 3 to 5 under the claimed test conditions? For the ’238 Patent, does the manufacturing process described in the ANDA involve "granulating separately" the chlorthalidone-containing part from the azilsartan-containing part?
    • Scope Questions (’249 Patent): A key dispute may center on whether the language in the Defendant's proposed product label is specific enough to encourage, recommend, or promote an infringing use, thereby meeting the requirements for inducement.

V. Key Claim Terms for Construction

For the ’936 Patent

  • The Term: "a solid pH control agent which provides a pH of 3 to 5 when dissolved or suspended in water at a concentration of 1% w/v at 25° C."
  • Context and Importance: This term is the central feature of the asserted composition claim, defining the component that allegedly solves the stability problem. Whether the excipients in the ANDA product meet this functional definition will be critical to the infringement analysis. Practitioners may focus on whether this functional language limits the claim to specific agents or covers any substance that achieves the claimed pH result.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The specification provides a long list of exemplary acidic substances that can be used, including "tartaric acid, citric acid, lactic acid, fumaric acid, malic acid," suggesting the term is not limited to a specific chemical class (’936 Patent, col. 5:4-13).
    • Evidence for a Narrower Interpretation: The patent repeatedly ties the pH control agent to the specific problem of balancing stability and solubility (’936 Patent, col. 2:6-15). The specification also identifies "monosodium fumarate" as "particularly preferable" and provides examples using a specific combination of "fumaric acid and sodium hydroxide," which could be used to argue the invention is focused on buffering agents that operate in a specific way (’936 Patent, col. 5:40-42).

For the ’238 Patent

  • The Term: "obtained by granulating separately from the first part"
  • Context and Importance: This process limitation defines the structural nature of the claimed combination tablet. Infringement depends directly on the manufacturing process described in the ANDA. The dispute will likely concern what level of physical and procedural separation is required to meet this limitation.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The claim language is straightforward and could be read to cover any manufacturing process where the diuretic granules are formed in a step distinct from the formation of the azilsartan granules, prior to final blending and compression.
    • Evidence for a Narrower Interpretation: The detailed examples describe specific granulation techniques, such as using a "fluid bed granulator" for both components (’238 Patent, Ex. 1, col. 13:7-22). A defendant may argue that the term implies a certain type or quality of granulation and separation, as exemplified in the specification, rather than any and all methods of separate granulation.

VI. Other Allegations

  • Indirect Infringement: The complaint alleges inducement and contributory infringement for all patents-in-suit. It alleges Defendant had "actual and constructive knowledge" of the patents prior to filing its ANDA and acted with "specific intent" to infringe (Compl. ¶¶ 32-33, 41-42, 50-51). The complaint further alleges that there are "no substantial non-infringing uses" for the ANDA Products, particularly for the method patent, where the proposed labeling is alleged to induce infringement by instructing an infringing use (Compl. ¶¶ 34, 43, 49, 52).
  • Willful Infringement: The complaint does not use the term "willful," but the allegations of pre-filing knowledge of the patents and specific intent to infringe provide a basis for such a claim (Compl. ¶¶ 32-33, 41-42, 50-51). The prayer for relief seeks a finding that the case is "exceptional" under 35 U.S.C. § 285, which is often associated with findings of willful infringement or other litigation misconduct (Compl. Prayer ¶ H).

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

  • A core issue will be one of compositional and procedural identity: will discovery of the confidential ANDA reveal that Defendant's product contains excipients that function as the claimed "pH control agent" under the specific test conditions of the ’936 Patent, and is it manufactured using the "separate granulation" process required by the ’238 Patent?
  • A second key issue will be one of inducement: does the specific language in the Defendant’s proposed product label actively encourage or instruct a method of administration that meets every limitation of the treatment method claimed in the ’249 Patent, or does it merely describe a condition of use without rising to the level of inducement?