DCT

1:22-cv-01604

Azurity Pharma Inc v. Glenmark Pharma Ltd

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I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 1:22-cv-01604, D. Del., 12/16/2022
  • Venue Allegations: Venue is alleged to be proper based on Defendant Glenmark USA’s incorporation in Delaware, its systematic and continuous contacts with the state, and its history of litigating in the district without challenging personal jurisdiction.
  • Core Dispute: Plaintiffs allege that Defendants' filing of an Abbreviated New Drug Application (ANDA) to market a generic version of the hypertension drug EDARBI® constitutes an act of infringement of a patent covering the drug's formulation.
  • Technical Context: The lawsuit concerns pharmaceutical formulation technology, specifically methods for ensuring that an active drug ingredient is both stable during storage and effectively dissolved and absorbed by the body upon ingestion.
  • Key Procedural History: This action was initiated under the Hatch-Waxman Act following Plaintiffs' receipt of a "Paragraph IV" certification notice from Defendants, which asserted that the patent-in-suit is invalid, unenforceable, or would not be infringed by the proposed generic product. The complaint was filed within the 45-day statutory window, triggering a potential 30-month stay of FDA approval for the generic. The patent-in-suit is listed in the FDA's "Orange Book" as covering EDARBI®.

Case Timeline

Date Event
2007-03-28 U.S. Patent No. 9,066,936 Priority Date
2015-06-30 U.S. Patent No. 9,066,936 Issue Date
2022-11-17 Date Plaintiffs received Glenmark's ANDA Notice Letter
2022-12-16 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”

  • Patent Identification: U.S. Patent No. 9,066,936, “Solid pharmaceutical composition comprising a benzimidazole-7-carboxylate derivative and a pH control agent,” issued June 30, 2015.

The Invention Explained

  • Problem Addressed: The patent addresses a common challenge with a specific class of therapeutic compounds (benzimidazole derivatives). The active ingredient, referred to as "compound (I)," is unstable in the neutral pH range typical for pharmaceutical preparations, but its solubility is low at the more acidic pH range where it is stable ('936 Patent, col. 2:7-12). This creates a dilemma where conditions favoring stability undermine solubility and dissolution, and vice-versa.
  • The Patented Solution: The invention is a solid pharmaceutical composition that combines the active ingredient with a "pH control agent." This agent is chosen to create a local acidic micro-environment within the solid dosage form (specifically, a pH between 3 and 5), which stabilizes the active ingredient during storage ('936 Patent, col. 21:20-22). The inventors found that this combination also unexpectedly improves the dissolution of the drug from the tablet upon administration, thereby solving both the stability and solubility problems simultaneously ('936 Patent, col. 2:24-34).
  • Technical Importance: This formulation strategy provides a way to deliver an otherwise difficult-to-formulate drug in a stable and bioavailable oral tablet form ('936 Patent, col. 2:25-30).

Key Claims at a Glance

  • The complaint asserts infringement of "one or more claims" of the '936 patent (Compl. ¶A, Prayer for Relief). The patent contains one independent claim, Claim 1.
  • Independent Claim 1 requires:
    • A solid pharmaceutical composition comprising the 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 active ingredient, also known as azilsartan medoxomil potassium).
    • 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.

III. The Accused Instrumentality

Product Identification

  • The accused instrumentality is the "Glenmark Generic Product," an oral tablet containing 40 mg or 80 mg of azilsartan medoxomil, for which Defendant Glenmark submitted Abbreviated New Drug Application (ANDA) No. 216378 to the FDA (Compl. ¶17).

Functionality and Market Context

  • The Glenmark Generic Product is alleged to contain the same active ingredient as Plaintiffs' branded drug, EDARBI®, and is intended to be a generic equivalent (Compl. ¶18). The filing of the ANDA is a statutory act of infringement under 35 U.S.C. § 271(e)(2) that allows for litigation prior to the commercial launch of the generic drug (Compl. ¶26).

IV. Analysis of Infringement Allegations

The complaint bases its infringement allegation on the statutory act of filing the ANDA and does not provide a detailed, element-by-element infringement analysis or a claim chart. The complaint states that Glenmark has not provided a copy of its ANDA or detailed information about the generic product's formulation (Compl. ¶22).

'936 Patent Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
a solid pharmaceutical composition comprising a compound which is (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 Glenmark Generic Product is an oral tablet alleged to contain "azilsartan medoxomil" as its active ingredient, the same as the branded drug EDARBI®. ¶17, ¶18 col. 21:14-19
and 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. The complaint does not provide sufficient detail for analysis of this element. The infringement allegation is based on the filing of the ANDA itself, which seeks approval for a product that Plaintiffs allege will fall within the scope of the patent's claims. ¶23, ¶26 col. 21:20-22
  • Identified Points of Contention:
    • Technical Questions: A central factual question for discovery will be identifying the excipients used in the Glenmark Generic Product. Does the formulation contain a substance or combination of substances that qualifies as a "solid pH control agent" and, if so, does that agent meet the precise functional requirement of providing "a pH of 3 to 5" under the test conditions specified in the claim?
    • Scope Questions: The claim recites the "potassium salt" of the active ingredient ('936 Patent, col. 21:19). The complaint describes the accused product as containing "azilsartan medoxomil" (Compl. ¶17). A potential dispute may arise over whether the specific salt form used in the Glenmark product is the same as that required by the claim.

No probative visual evidence provided in complaint.

V. Key Claim Terms for Construction

  • 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 defines the core inventive concept of the patent. The infringement analysis will likely depend entirely on whether an excipient or combination of excipients in Glenmark's formulation meets this functional definition. Practitioners may focus on this term because it is not a standard chemical name but a functional limitation that will require testing and interpretation to apply to the accused product.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The patent specification provides a broad list of potential acidic and basic substances that could be used or combined to achieve the desired pH, including tartaric acid, citric acid, fumaric acid, and various salts and bases ('936 Patent, col. 5:4-13, col. 5:26-35). This could support an argument that the term covers any agent or combination of agents that achieves the claimed functional result.
    • Evidence for a Narrower Interpretation: The patent also provides more specific guidance. It states that "preferable examples of the pH control agent" are those with "a buffering ability at said pH, such as sodium dihydrogen phosphate, monosodium fumarate and the like" ('936 Patent, col. 6:36-39). The abstract and summary also emphasize the "co-presence" of the agent and compound to "unexpectedly" improve dissolution, which could be argued to require more than simply creating an acidic environment ('936 Patent, Abstract; col. 2:27-34). Dependent Claim 2 further narrows the agent to "monosodium fumarate or a combination of fumaric acid and sodium hydroxide" ('936 Patent, col. 22:3-5).

VI. Other Allegations

  • Indirect Infringement: The complaint alleges that upon approval, Defendants' commercial activities and proposed product labeling would induce and/or contribute to the infringement of the '936 patent (Compl. ¶27).
  • Willful Infringement: Willfulness is alleged based on Defendants' awareness of the '936 patent and their knowledge that filing the ANDA with a Paragraph IV certification constituted an act of infringement (Compl. ¶30).

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

  • An Evidentiary Question of Composition: The primary issue is factual and will be resolved through discovery: what are the specific ingredients and formulation characteristics of the Glenmark Generic Product as detailed in its ANDA? The case hinges on whether that formulation contains excipients that function as a "pH control agent" meeting the precise quantitative limits of Claim 1.
  • A Definitional Question of Function: A core legal issue will be the construction of the claim term "a solid pH control agent which provides a pH of 3 to 5...". The outcome of the case will likely turn on whether this term is interpreted broadly to cover any substance that results in the target pH, or more narrowly to require a specific buffering capacity or one of the preferred agents disclosed in the patent.