DCT

1:23-cv-00079

Azurity Pharma Inc v. Alkem Laboratories Ltd

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I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 1:23-cv-00079, D.N.J., 01/06/2023
  • Venue Allegations: Venue is alleged based on Defendant’s persistent and continuous business contacts with New Jersey, including the development, marketing, and sale of generic pharmaceutical products, from which it allegedly derives substantial revenue. The complaint also notes that the judicial district is a likely destination for the accused product.
  • Core Dispute: Plaintiffs allege that Defendant’s submission of an Abbreviated New Drug Application (ANDA) to the FDA for a generic topiramate oral solution constitutes an act of infringement of a patent covering a stable, liquid formulation of the drug.
  • Technical Context: The technology concerns liquid oral formulations of topiramate, an anti-epileptic drug, designed to be stable without refrigeration and ready-to-use, which is particularly relevant for patients who have difficulty swallowing solid tablets.
  • Key Procedural History: This is a Hatch-Waxman action filed under 35 U.S.C. § 271(e)(2), triggered by a November 21, 2022 notice letter from Defendant Alkem to Plaintiffs, informing them of its ANDA submission. The patent-in-suit is listed in the FDA's "Orange Book" in connection with Plaintiff Azurity’s Eprontia® product.

Case Timeline

Date Event
2019-12-10 '046 Patent Priority Date
2022-09-06 '046 Patent Issue Date
2022-11-21 Defendant Alkem sends ANDA Notice Letter
2023-01-06 Complaint Filing Date

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

U.S. Patent No. 11,433,046 - "Compositions and Methods for Treating Epilepsy, Seizures and Other Conditions"

  • Issued: September 6, 2022.

The Invention Explained

  • Problem Addressed: The patent describes that topiramate, a widely used anti-seizure medication, is not stable in aqueous (water-based) solutions and degrades via hydrolysis. (’046 Patent, col. 1:63-65). This instability has historically made it difficult to create a ready-to-use, room-temperature-stable oral liquid formulation, forcing reliance on solid dosage forms or liquid "preconcentrates" that require dilution before administration (’046 Patent, col. 2:1-14).
  • The Patented Solution: The invention is a "substantially anhydrous" (i.e., containing very little or no water) liquid formulation of topiramate. It uses a specific solvent system of organic solvents, such as polyethylene glycol and glycerin, to dissolve the topiramate and keep it stable. (’046 Patent, Abstract; col. 2:21-30). This creates a "ready-to-use" solution that does not require dilution and is stable at room temperature for at least two years, solving the prior art’s stability and administration problems (’046 Patent, col. 2:12-17, 25-28).
  • Technical Importance: The invention provides a convenient, stable, and ready-to-use liquid dosage form for patients, including pediatric and adult populations, who cannot take solid tablets, potentially improving dosing accuracy and patient compliance. (’046 Patent, col. 2:12-17).

Key Claims at a Glance

  • The complaint asserts infringement of "one or more claims" without specifying which ones (Compl. ¶26). Independent claim 1 is a representative method of treatment claim.
  • Essential elements of independent claim 1 include:
    • A method for treating specific disorders (epilepsy, seizures, migraine) consisting of orally administering a pharmaceutical composition.
    • The composition is an oral liquid solution "consisting of" five components:
      1. Topiramate at a concentration of "about 25 mg/ml."
      2. A solvent component (from "about 80% to about 120% w/v") which itself "consists of" glycerin (60-65% w/v) and polyethylene glycol 400 (45-55% w/v).
      3. One or more preservatives from a specified list.
      4. One or more sweeteners.
      5. A flavor component.
    • The composition is "substantially anhydrous."
  • The complaint does not explicitly reserve the right to assert dependent claims.

III. The Accused Instrumentality

Product Identification

  • Defendant Alkem's generic topiramate oral solution, for which it submitted ANDA No. 217795 to the FDA (the "Alkem ANDA Product") (Compl. ¶1, ¶18).

Functionality and Market Context

  • The complaint alleges that Alkem's ANDA Product has the "same active ingredients," "same route of administration, dosage form, use, and strength" as Azurity's branded Eprontia® Product and is "bioequivalent" to it (Compl. ¶23).
  • The proposed labeling for the Alkem ANDA Product allegedly directs its use as a method for treating epilepsy, various types of seizures, and migraine, mirroring the indications for Eprontia® and the methods recited in the patent's claims (Compl. ¶20). No probative visual evidence provided in complaint.

IV. Analysis of Infringement Allegations

The complaint does not include a claim chart. The infringement theory is based on Alkem’s submission of an ANDA for a product that, if approved and marketed with its proposed label, would allegedly infringe the '046 patent. The following chart summarizes the allegations for a representative claim.

'046 Patent Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
A method for treating a disease or disorder ... selected from: epilepsy, onset seizures, primary generalized tonic-clonic seizures, seizures associated with Lennox-Gastaut syndrome, and migraine... The proposed labeling for Alkem's ANDA Product allegedly directs its use for these specific conditions. ¶20 col. 29:11-15
...consisting of orally administering... a pharmaceutical composition... formulated as a solution and wherein the... composition consists of: (i) topiramate... in an amount of about 25 mg/ml... Alkem's ANDA Product is alleged to be a bioequivalent oral solution with the same strength as Azurity's Eprontia® product. ¶23 col. 29:1-2
(ii) a solvent component comprising one or more organic solvents... wherein the solvent component consists of glycerin in an amount of 60% to 65% w/v and polyethylene glycol... in an amount of 45% to 55% w/v... The complaint does not provide the specific formulation of Alkem's ANDA product but alleges it is a bioequivalent generic version of a product covered by the patent. ¶17, ¶23 col. 28:56-65
(iii) one or more preservatives... (iv) one or more sweeteners; and (v) a flavor component... As a bioequivalent, the Alkem ANDA Product is alleged to contain the necessary excipients to match the patented composition's characteristics. ¶23 col. 29:3-7
wherein the liquid pharmaceutical composition is substantially anhydrous... The complaint alleges that the use of Azurity's product is covered by the patent, and Alkem's product is alleged to be bioequivalent. ¶17, ¶23 col. 29:10-11
  • Identified Points of Contention:
    • Technical Questions: A primary factual dispute will be whether Alkem's ANDA Product formulation literally meets the specific compositional limitations of the asserted claims. The complaint relies on allegations of bioequivalence rather than providing Alkem's actual formulation. Discovery will be required to determine if Alkem's product contains glycerin and polyethylene glycol in the claimed weight/volume percentages and if it is "substantially anhydrous" as defined in the patent.
    • Scope Questions: The use of the transitional phrase "consisting of" for both the method and the composition is highly restrictive. A central legal question will be whether Alkem's product contains any unlisted excipients. If it does, Alkem may argue that its formulation falls outside the scope of claims that use this "closed" language.

V. Key Claim Terms for Construction

The Term: "substantially anhydrous"

  • Context and Importance: This term is the technological core of the patent, distinguishing the invention from prior art unstable aqueous solutions. Whether Alkem's product infringes will depend heavily on whether it meets this limitation.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The specification states that as applied to the composition, "substantially anhydrous" is "intended to mean that the composition does not contain any added water" (’046 Patent, col. 18:17-19). A plaintiff may argue this is the controlling definition.
    • Evidence for a Narrower Interpretation: The specification also provides quantitative limits, stating the compositions "contain less than about 0.5% w/w total water" and provides even narrower exemplary ranges, such as "about 0.35% w/w or less" or "devoid of detectable water" (’046 Patent, col. 18:24-32). A defendant could argue for one of these more restrictive quantitative definitions.

The Term: "consisting of"

  • Context and Importance: This term, appearing in the preamble of claim 1 ("consisting of orally administering") and in the body ("composition consists of"), is one of the most restrictive in patent law, typically excluding any unlisted elements. Its construction will be critical to determining if Alkem's formulation, which may contain different or additional excipients, can infringe. Practitioners may focus on this term because even minor, unrecited ingredients in Alkem's product could form a basis for a non-infringement defense.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: A plaintiff might argue that standard excipients that do not materially alter the basic and novel characteristics of the invention should not preclude infringement, attempting to soften the term's typically rigid meaning. However, the claim's use of "consisting of" rather than "consisting essentially of" weakens this position.
    • Evidence for a Narrower Interpretation: The patent explicitly uses "consisting essentially of" in the specification, but the drafters chose the stricter "consisting of" for claim 1. A defendant will argue this choice was deliberate and that the claim must be read to exclude any and all unrecited ingredients, such as different preservatives, antioxidants, or other inactive ingredients not falling within the five listed categories. (’046 Patent, col. 5:10, col. 8:22, col. 29:1).

VI. Other Allegations

  • Indirect Infringement: The complaint alleges induced infringement, stating that Alkem plans and intends for physicians and patients to infringe by following the instructions on its proposed product labeling (Compl. ¶30). It also alleges contributory infringement, asserting that Alkem's product is especially made or adapted for infringing use and is not suitable for substantial non-infringing use (Compl. ¶31).
  • Willful Infringement: The complaint alleges that Alkem had "actual and constructive knowledge" of the '046 patent, in part because the patent is listed in the FDA's Orange Book, and that its submission of the ANDA was an intentional act of infringement (Compl. ¶28-29).

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

  • A central question will be one of compositional identity: does the precise formulation of Alkem’s ANDA product, once revealed in discovery, fall within the specific and narrow compositional limitations of the asserted claims, particularly with respect to the "substantially anhydrous" requirement and the exact weight/volume percentages of the claimed solvents?
  • A dispositive legal issue will be the scope of the claims: how will the court construe the highly restrictive "consisting of" language? The presence of any unlisted excipient in Alkem's product could provide a straightforward path to a non-infringement judgment, making the interpretation of this term paramount.