DCT

2:23-cv-23273

Azurity Pharma Inc v. Aurobindo Pharma Ltd

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I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 2:23-cv-23273, D.N.J., 12/21/2023
  • Venue Allegations: Venue is alleged to be proper in the District of New Jersey because Defendant Aurobindo Pharma USA, Inc. has its principal place of business in New Jersey, and the district is a likely destination for the accused generic products.
  • Core Dispute: Plaintiff alleges that Defendant’s Abbreviated New Drug Application (ANDA) seeking approval to market a generic version of Plaintiff's FIRVANQ® product constitutes an act of infringement of seven patents related to stable oral liquid formulations of vancomycin.
  • Technical Context: The technology concerns pharmaceutical compositions that provide the antibiotic vancomycin as a stable, palatable oral liquid, primarily for treating Clostridium difficile-associated diarrhea in patients, such as children and the elderly, who may have difficulty with solid dosage forms.
  • Key Procedural History: The litigation was triggered by a November 3, 2023 notice letter from Aurobindo to Azurity, informing Azurity of its ANDA submission containing a Paragraph IV certification against the asserted patents, which is the statutory act of infringement in this case. The complaint notes that Aurobindo's letter stated its generic product does not contain a specific recited excipient and includes other unidentified components.

Case Timeline

Date Event
2014-03-14 Earliest Priority Date for all Asserted Patents
2019-12-03 U.S. Patent No. 10,493,028 Issues
2020-06-23 U.S. Patent No. 10,688,046 Issues
2021-03-30 U.S. Patent Nos. 10,959,946, 10,959,947, 10,959,948, and 10,959,949 Issue
2023-05-02 U.S. Patent No. 11,638,692 Issues
2023-11-03 Aurobindo sends Notice Letter to Azurity regarding ANDA filing
2023-12-21 Complaint Filed

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

U.S. Patent No. 10,493,028 - "Composition and Method for Vancomycin Oral Liquid"

The Invention Explained

  • Problem Addressed: The patent’s background section describes the difficulty of administering vancomycin, an important antibiotic for treating C. difficile, to pediatric and geriatric populations who cannot easily swallow capsules (U.S. Patent No. 10,493,028, col. 5:1-7). Compounding an oral liquid from the sterile powder form for injection is described as cumbersome for pharmacists, often unflavored to mask bitterness, and potentially unsafe due to contamination risks from its lack of preservatives (’028 Patent, col. 5:25-54).
  • The Patented Solution: The invention is a non-sterile, stable liquid formulation of vancomycin hydrochloride powder that, when compounded, creates a solution that is homogenous and stable for at least 30 days at both ambient and refrigerated temperatures (’028 Patent, col. 2:25-31). The formulation includes specific excipients such as a buffering agent, sweetener, flavoring agent, and a preservative to ensure stability and palatability (’028 Patent, col. 2:51-67). The invention also provides for a kit containing pre-measured amounts of the vancomycin powder and the liquid solution components for easy reconstitution by a pharmacist (’028 Patent, Fig. 1; col. 3:17-41).
  • Technical Importance: This approach provides a ready-to-compound, stable, palatable, and preserved vancomycin oral liquid, addressing a need for a more convenient and safer alternative to both solid oral dosage forms and ad-hoc compounded preparations from injectable powder (’028 Patent, col. 6:55-65).

Key Claims at a Glance

  • The complaint asserts infringement of one or more claims of the ’028 Patent (Compl. ¶62). Independent claim 1 is representative of the patented composition.
  • Essential elements of Independent Claim 1:
    • A non-sterile stable liquid formulation formulated for oral administration, consisting of:
    • (a) 0.1-0.4% w/v anhydrous citric acid,
    • (b) water,
    • (c) 0.1-0.3% w/v sucralose,
    • (d) 0.01-0.1% w/v of a flavoring agent,
    • (e) 0.08-0.2% w/v sodium benzoate,
    • (f) 0.0001-0.0003% w/v of a dye, and
    • (g) vancomycin hydrochloride,
    • wherein the non-sterile stable liquid formulation is homogenous and stable for at least 30 days at ambient and refrigerated temperature conditions and has a pH of 2.5-4.5, and wherein the concentration of vancomycin in the solution is 25-50 mg/ml.
  • The complaint reserves the right to assert additional claims, which could include dependent claims (Compl. ¶63).

U.S. Patent No. 10,688,046 - "Composition and Method for Vancomycin Oral Liquid"

The Invention Explained

  • Problem Addressed: This patent, part of the same family as the ’028 Patent, addresses the same technical problems of providing a stable, palatable, and preserved oral liquid form of vancomycin for patients unable to take solid dosage forms (U.S. Patent No. 10,688,046, col. 5:1-54).
  • The Patented Solution: The solution is materially identical to that described in the ’028 Patent: a non-sterile, stable liquid formulation of vancomycin hydrochloride containing a specific combination of excipients including a buffering agent, a sweetener, a flavoring agent, and a preservative, designed to be stable for at least 30 days after compounding (’046 Patent, Abstract; col. 2:25-31).
  • Technical Importance: As with the ’028 Patent, the invention provides a standardized, safe, and easy-to-use alternative to existing vancomycin dosage forms, improving patient compliance and reducing the burden and risk associated with pharmacy compounding (’046 Patent, col. 6:55-65).

Key Claims at a Glance

  • The complaint asserts infringement of one or more claims of the ’046 Patent (Compl. ¶70). Independent claim 8 is representative of a method of treating a patient with the patented composition.
  • Essential elements of Independent Claim 8:
    • A method of treating Clostridium difficile pseudomembranous colitis or Staphylococcal enterocolitis in a subject
    • comprising administering a vancomycin oral liquid composition to the subject in a therapeutically effective amount,
    • wherein the vancomycin oral liquid composition consists of:
    • (a) 0.1-0.4% w/v citric acid,
    • (b) water,
    • (c) a sweetener that is sucralose,
    • (d) 0.02-0.08% w/v sodium benzoate,
    • (e) 20-60 mg/ml vancomycin hydrochloride, and
    • (f) flavoring agent,
    • wherein the vancomycin oral liquid composition is homogenous and stable for at least 2 weeks at ambient and refrigerated temperature and has a pH of 2.5-4.5.
  • The complaint reserves the right to assert additional claims (Compl. ¶71).

U.S. Patent No. 10,959,946 - "Composition and Method for Vancomycin Oral Liquid"

  • Technology Synopsis: This patent discloses a non-sterile stable liquid formulation of vancomycin hydrochloride and a liquid solution for compounding it. The formulation is designed to be homogenous and stable for at least 30 days, addressing the need for a reliable oral liquid dosage form (’946 Patent, Abstract; col. 1:19-24).
  • Asserted Claims: The complaint asserts one or more claims, including independent claims 1 and 2 (Compl. ¶78).
  • Accused Features: The accused features are Aurobindo's ANDA products, which are alleged to be bioequivalent generic versions of Azurity's FIRVANQ® oral solution (Compl. ¶57, ¶80).

U.S. Patent No. 10,959,947 - "Composition and Method for Vancomycin Oral Liquid"

  • Technology Synopsis: This patent claims a non-sterile stable liquid formulation of vancomycin hydrochloride that includes specific excipients to ensure stability and palatability. The invention is directed at providing an improved oral liquid dosage form of vancomycin for treating infections like C. difficile (’947 Patent, Abstract; col. 1:19-24).
  • Asserted Claims: The complaint asserts one or more claims, including independent claims 1 and 5 (Compl. ¶86).
  • Accused Features: The accused features are Aurobindo's ANDA products, which are alleged to be bioequivalent generic versions of Azurity's FIRVANQ® oral solution (Compl. ¶57, ¶88).

U.S. Patent No. 10,959,948 - "Composition and Method for Vancomycin Oral Liquid"

  • Technology Synopsis: This patent claims a non-sterile stable liquid formulation of vancomycin and a method for its preparation. The formulation uses specific concentrations of excipients, including citric acid, sucralose, sodium benzoate, and a flavoring agent to create a stable oral liquid (’948 Patent, Abstract; col. 1:19-24).
  • Asserted Claims: The complaint asserts one or more claims, including independent claims 1 and 7 (Compl. ¶94).
  • Accused Features: The accused features are Aurobindo's ANDA products, which are alleged to be bioequivalent generic versions of Azurity's FIRVANQ® oral solution (Compl. ¶57, ¶96).

U.S. Patent No. 10,959,949 - "Composition and Method for Vancomycin Oral Liquid"

  • Technology Synopsis: This patent is directed to a liquid solution for preparing a vancomycin oral liquid formulation. The claimed solution contains specific excipients that, when combined with vancomycin hydrochloride, produce a stable and homogenous final product for oral administration (’949 Patent, Abstract; col. 1:19-24).
  • Asserted Claims: The complaint asserts one or more claims, including independent claim 1 (Compl. ¶102).
  • Accused Features: The accused features are Aurobindo's ANDA products, which are alleged to be bioequivalent generic versions of Azurity's FIRVANQ® oral solution (Compl. ¶57, ¶104).

U.S. Patent No. 11,638,692 - "Composition and Method for Vancomycin Oral Liquid"

  • Technology Synopsis: This patent claims a non-sterile stable liquid formulation containing vancomycin hydrochloride and specific excipients, including a buffering agent and a preservative. The formulation is designed to be stable for at least one week at ambient and refrigerated temperatures (’692 Patent, Abstract; col. 1:21-26).
  • Asserted Claims: The complaint asserts one or more claims, including independent claims 1 and 5 (Compl. ¶110).
  • Accused Features: The accused features are Aurobindo's ANDA products, which are alleged to be bioequivalent generic versions of Azurity's FIRVANQ® oral solution (Compl. ¶57, ¶112).

III. The Accused Instrumentality

  • Product Identification: The accused instrumentalities are the generic vancomycin hydrochloride oral solution products that are the subject of Aurobindo’s ANDA No. 218130 (“Aurobindo’s ANDA Products”) (Compl. ¶1, ¶7).
  • Functionality and Market Context: The complaint alleges that Aurobindo's ANDA Products are generic versions of Azurity's FIRVANQ® product, an FDA-approved treatment for Clostridium difficile-associated diarrhea and staphylococcal enterocolitis (Compl. ¶1, ¶15). As a generic, Aurobindo’s product is alleged to have the same active ingredient, route of administration, dosage form, use, and strength as FIRVANQ®, and to be bioequivalent to it (Compl. ¶57). Like FIRVANQ®, the accused products are supplied as a powder that must be reconstituted by a healthcare provider to produce the final oral solution for administration to the patient (Compl. ¶58, ¶64). No probative visual evidence provided in complaint.

IV. Analysis of Infringement Allegations

The complaint does not provide a detailed claim chart or technical breakdown of the accused products. The infringement allegations are based on the premise that by filing an ANDA for a bioequivalent generic drug, Aurobindo's product will necessarily meet the limitations of the asserted patents once reconstituted and sold (Compl. ¶57, ¶64). The following chart summarizes the allegations for a representative claim.

10,493,028 Patent Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
A non-sterile stable liquid formulation formulated for oral administration, consisting of: Aurobindo's ANDA Products, upon reconstitution, are alleged to be a non-sterile stable liquid formulation for oral administration. ¶64 col. 14:15-17
(a) 0.1-0.4% w/v anhydrous citric acid,...(g) vancomycin hydrochloride The ANDA Products are alleged to contain the same active ingredient as FIRVANQ® and a formulation that is bioequivalent, and therefore are alleged to contain these components or their equivalents upon reconstitution. ¶57, ¶64 col. 14:18-24
wherein the non-sterile stable liquid formulation is homogenous and stable for at least 30 days at ambient and refrigerated temperature conditions By seeking approval as a generic equivalent, Aurobindo's product is alleged to possess the required stability and homogeneity characteristics of the branded drug. ¶57, ¶64 col. 14:25-28
and has a pH of 2.5-4.5, and wherein the concentration of vancomycin...is 25-50 mg/ml. The ANDA Products are alleged to have the same strength and dosage form as FIRVANQ®, requiring them to meet the claimed pH and concentration parameters upon reconstitution. ¶57, ¶64 col. 14:28-31

10,688,046 Patent Infringement Allegations

Claim Element (from Independent Claim 8) Alleged Infringing Functionality Complaint Citation Patent Citation
A method of treating Clostridium difficile pseudomembranous colitis...comprising administering a vancomycin oral liquid composition to the subject Aurobindo's proposed product label is alleged to be substantially identical to the FIRVANQ® label, instructing use for treating C. difficile, thereby inducing infringement of the method. ¶59, ¶72, ¶74 col. 14:41-47
wherein the vancomycin oral liquid composition consists of: (a) 0.1-0.4% w/v citric acid,...(f) flavoring agent Aurobindo's ANDA Products, upon reconstitution, are alleged to form a composition containing these elements or their equivalents, as required to be bioequivalent to FIRVANQ®. ¶57, ¶72 col. 14:48-56
wherein the vancomycin oral liquid composition is homogenous and stable for at least 2 weeks...and has a pH of 2.5-4.5. As a proposed bioequivalent generic, Aurobindo's product is alleged to meet the required stability and pH characteristics of the claimed method. ¶57, ¶72 col. 14:57-60

Identified Points of Contention

  • Compositional Scope Questions: The complaint explicitly notes that Aurobindo’s notice letter stated its "ANDA Products do not contain an excipient recited in certain patent claims and do 'include' unidentified 'components' that are allegedly not explicitly recited in the claims" (Compl. ¶54). This raises the central question of whether Aurobindo’s formulation literally infringes claims that use the transitional phrase "consisting of" (e.g., ’028 Patent, Claim 1), which typically limits the invention to only the listed elements. It also raises the question of whether any differences in excipients are substantial enough to avoid infringement under the doctrine of equivalents.
  • Technical Questions: What is the identity of the allegedly omitted excipient and the "unidentified components" in Aurobindo's product? The complaint does not provide sufficient detail for analysis of this point, but it will be a key factual issue for the court in determining whether there is a material difference between the claimed invention and the accused product.

V. Key Claim Terms for Construction

The Term: "consisting of"

  • Context and Importance: This term appears in the preamble of independent claim 1 of the ’028 Patent and independent claim 8 of the ’046 Patent. Practitioners may focus on this term because it is a closed transition phrase, meaning the claimed formulation must not contain any other material components. Given Aurobindo's alleged assertion that its product includes "unidentified components" (Compl. ¶54), the construction of this term will be critical to the literal infringement analysis.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: A court could interpret "consisting of" to permit additional components that do not materially affect the basic and novel properties of the invention, such as its stability and homogeneity. The patent’s focus on achieving a stable liquid formulation could support an interpretation where only additives that affect these core properties are excluded.
    • Evidence for a Narrower Interpretation: The plain meaning of "consisting of" is strictly limiting. A defendant may argue that the claim is explicitly defined by the seven listed components in Claim 1 of the ’028 Patent, and the presence of any other active or functional excipient would place the accused product outside the claim's literal scope. The detailed recitation of specific components and their weight/volume percentages may support this narrower reading (’028 Patent, col. 14:18-24).

The Term: "homogenous and stable for at least 30 days"

  • Context and Importance: This limitation, present in Claim 1 of the ’028 Patent, defines a key performance characteristic of the invention. The dispute may turn on the specific technical standard required to prove stability. Practitioners may focus on this term because the patent describes multiple methods for assessing stability, including microbial assays and HPLC, which could yield different results (’028 Patent, col. 10:15-32; col. 12:31-57).
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The specification describes stability generally as maintaining at least 98% vancomycin at the end of a storage period (’046 Patent, col. 12:33-36). This could support a functional definition of stability rather than one tied to a specific testing protocol.
    • Evidence for a Narrower Interpretation: The patent includes detailed examples with specific stability data under various conditions (e.g., ’028 Patent, col. 17-18). A defendant may argue that "stable" should be construed to mean achieving results comparable to those disclosed in the patent’s own examples, potentially narrowing the claim's scope to exclude formulations that are stable but to a lesser degree.

VI. Other Allegations

  • Indirect Infringement: The complaint alleges inducement of infringement against Aurobindo (Compl. ¶66, ¶74). The basis for this allegation is that Aurobindo’s proposed product label will instruct pharmacists or other users to reconstitute the supplied powder to create the final oral solution, which is the allegedly infringing product (Compl. ¶64, ¶72).
  • Willful Infringement: The complaint does not contain an explicit count for willful infringement, but it lays the groundwork by alleging that Aurobindo had "actual and constructive knowledge" of the asserted patents prior to the lawsuit (Compl. ¶65, ¶73). This knowledge is based on Aurobindo’s submission of a Paragraph IV certification and its November 3, 2023 notice letter to Azurity (Compl. ¶51-52).

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

  • A core issue will be one of compositional scope: Can Azurity prove that Aurobindo's formulation, which allegedly contains different excipients than those explicitly recited, falls within the scope of patent claims that use the restrictive "consisting of" transition phrase, either literally or under the doctrine of equivalents?
  • A key evidentiary question will be one of technical fact: What are the "unidentified components" in Aurobindo's formulation and what is the excipient it allegedly omits, and do these differences materially alter the stability and homogeneity of the final reconstituted product compared to the patented invention?
  • A central question of claim construction will be: What technical and procedural standards does the term "homogenous and stable" require, and does the evidence from Aurobindo's ANDA filing demonstrate that its product will meet this standard upon reconstitution?