DCT

2:25-cv-15120

Baxter Healthcare Corp v. PH Health Ltd

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I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 2:25-cv-15120, D.N.J., 08/29/2025
  • Venue Allegations: Venue is alleged based on several of the Defendant entities maintaining a regular and established place of business in the District of New Jersey, including in Woodcliff Lake.
  • Core Dispute: Plaintiffs allege that Defendants' submission of an Abbreviated New Drug Application (ANDA) to market a generic version of the antiarrhythmic drug NEXTERONE® constitutes an act of patent infringement under the Hatch-Waxman Act.
  • Technical Context: The lawsuit centers on the purity of a pharmaceutical excipient known as a sulfoalkyl ether cyclodextrin, which is used to improve the solubility and stability of active drug ingredients.
  • Key Procedural History: The action was initiated in response to a Notice Letter dated July 16, 2025, in which Defendants provided a Paragraph IV certification against U.S. Patent No. 7,635,773, which is listed in the FDA's "Orange Book" as covering the NEXTERONE® product.

Case Timeline

Date Event
2008-04-28 ’773 Patent Priority Date
2008-12-24 FDA approves NEXTERONE® Injection
2009-12-22 ’773 Patent Issue Date
2011-06-01 Baxter launches ready-to-use NEXTERONE® IV bag
2025-07-16 Defendants send Paragraph IV Notice Letter
2025-08-29 Complaint Filing Date

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

U.S. Patent No. 7,635,773 - "SULFOALKYL ETHER CYCLODEXTRIN COMPOSITIONS"

  • Patent Identification: U.S. Patent No. 7,635,773, "SULFOALKYL ETHER CYCLODEXTRIN COMPOSITIONS," issued December 22, 2009 (’773 Patent).

The Invention Explained

  • Problem Addressed: The patent’s background section states that sulfoalkyl ether cyclodextrin (SAE-CD) compositions, which are used as pharmaceutical excipients, can contain impurities that "reduce the shelf-life and potency of an active agent composition" (’773 Patent, col. 2:7-9). It notes a "continued need for SAE-CD compositions with higher purity" (’773 Patent, col. 2:14-16).
  • The Patented Solution: The invention is a highly purified SAE-CD composition characterized by low levels of specific impurities. The patent describes a composition with less than 100 parts per million (ppm) of phosphate and a low level of a "drug-degrading agent," where the presence of the latter is quantified by its low absorbance of ultraviolet light within a specific wavelength range (’773 Patent, Abstract; col. 2:22-31). This enhanced purity is achieved by treating the SAE-CD solution with phosphate-free activated carbon (’773 Patent, col. 5:26-34).
  • Technical Importance: By providing a purer excipient, the invention allows for the creation of more stable pharmaceutical formulations, which can extend product shelf-life and better preserve the efficacy of the active drug ingredient (’773 Patent, col. 2:7-9; col. 10:28-33).

Key Claims at a Glance

  • The complaint alleges infringement of "one or more claims" without specifying particular claims (Compl. ¶66). Independent claim 1 is representative of the invention's composition claims.
  • Essential elements of Independent Claim 1:
    • A composition comprising an excipient and a sulfoalkyl ether cyclodextrin (SAE-CD) composition;
    • wherein the SAE-CD composition comprises a sulfoalkyl ether cyclodextrin and less than 100 ppm of a phosphate;
    • wherein the SAE-CD composition has an absorption of less than 0.2 A.U. due to a drug-degrading agent, as determined by UV/vis spectrophotometry at a wavelength of 245 nm to 270 nm for an aqueous solution containing 300 mg of the SAE-CD composition per mL of solution in a cell having a 1 cm path length.
  • The complaint does not explicitly reserve the right to assert dependent claims but makes a general allegation against the patent.

III. The Accused Instrumentality

Product Identification

  • The accused instrumentality is Defendants' proposed generic version of NEXTERONE® (Amiodarone Hydrochloride Injection, 150 mg/100 mL (1.5 mg/mL)), which is the subject of ANDA No. 219703 ("Defendants' ANDA Product") (Compl. ¶1).

Functionality and Market Context

  • The complaint identifies NEXTERONE® as an antiarrhythmic agent approved for treating ventricular fibrillation and ventricular tachycardia (Compl. ¶4, ¶40). Defendants' ANDA Product is intended to be a generic version of this commercial product (Compl. ¶1). To obtain FDA approval as a generic, the product must be bioequivalent to the branded drug, which suggests it likely contains a similar formulation, including a solubilizing excipient such as SAE-CD. The complaint alleges that upon approval, Defendants' ANDA Product will be marketed as a competing product to NEXTERONE® (Compl. ¶1).

No probative visual evidence provided in complaint.

IV. Analysis of Infringement Allegations

The complaint does not include a claim chart or detailed, element-by-element infringement allegations. The infringement claim is statutory, arising from the act of filing the ANDA under 35 U.S.C. § 271(e)(2)(A) (Compl. ¶66). The core of the infringement allegation is that the product described in Defendants' ANDA, if commercially manufactured and sold, would infringe one or more claims of the ’773 patent (Compl. ¶67). The central technical dispute will therefore be whether the composition of Defendants' ANDA Product falls within the scope of the patent's claims, specifically whether the SAE-CD excipient used in the generic formulation meets the purity limitations defined in the patent.

  • Identified Points of Contention:
    • Scope Questions: The primary dispute will concern whether the SAE-CD excipient in Defendants' ANDA Product meets the negative limitations of the claims. For example, does the excipient contain "less than 100 ppm of a phosphate"?
    • Technical Questions: A key evidentiary question will be whether Defendants' ANDA Product, when tested according to the specific protocol defined in the claims, exhibits "an absorption of less than 0.2 A.U. due to a drug-degrading agent" (’773 Patent, col. 54:26-34). The case may involve significant discovery and expert testimony regarding analytical chemistry testing methods and results.

V. Key Claim Terms for Construction

  • The Term: "drug-degrading agent"

    • Context and Importance: This term is central to the patent’s claim of novelty and non-obviousness, as it defines one of the key impurities the invention seeks to minimize. The infringement analysis will depend on whether an impurity in the accused product qualifies as a "drug-degrading agent" under the claim.
    • Intrinsic Evidence for Interpretation:
      • Evidence for a Broader Interpretation: The specification defines the term functionally as a species that "degrades an active component in aqueous solution" and provides a non-exhaustive list of examples, including "a glycosidic moiety, a ring-opened cyclodextrin species, a reducing sugar," and "carbonyl-containing degradants" (’773 Patent, col. 22:9-26). This language could support a construction that is not limited to any specific chemical structure but is instead defined by its degrading effect and its UV absorption characteristics.
      • Evidence for a Narrower Interpretation: Defendants may argue that the term should be limited to the specific types of impurities shown to arise from the degradation of cyclodextrin itself during manufacturing, as illustrated in figures like FIG. 3, which depicts the formation of such agents under thermal and caustic stress (’773 Patent, FIG. 3). This could support a narrower construction tied to the specific problem the inventors solved.

  • The Term: "as determined by UV/vis spectrophotometry at a wavelength of 245 nm to 270 nm for an aqueous solution containing 300 mg of the SAE-CD composition per mL of solution in a cell having a 1 cm path length"

    • Context and Importance: This clause provides the specific method for measuring the "drug-degrading agent" limitation. As a product-by-process or method-defined product characteristic, the enforceability of this limitation depends on the precise, reproducible execution of this test.
    • Intrinsic Evidence for Interpretation:
      • Evidence for a Broader Interpretation: Plaintiffs may argue that the claim recites standard analytical techniques and that any good-faith implementation of the described method that adheres to the explicit parameters (wavelength, concentration, path length) is sufficient to determine infringement.
      • Evidence for a Narrower Interpretation: The specification provides detailed examples of how UV/Vis analysis was conducted, including specific instruments and sample preparation methods (e.g., ’773 Patent, col. 45:51-64; col. 48:1-5). A party could argue these examples implicitly define required, but unstated, parameters of the test, potentially narrowing the scope of how infringement can be proven.

VI. Other Allegations

  • Indirect Infringement: The complaint includes general allegations of induced and contributory infringement (Compl. ¶66). In the context of an ANDA case, this theory typically rests on the argument that the proposed product label will instruct medical professionals and patients to use the generic drug in a manner that directly infringes.
  • Willful Infringement: The complaint alleges that Defendants were aware of the ’773 patent because it is listed in the FDA’s Orange Book for NEXTERONE® (Compl. ¶68). It further alleges that Defendants "acted without a reasonable basis for believing that it would not be liable for infringement," which Plaintiffs contend renders the case "exceptional" under 35 U.S.C. § 285 and supports a claim for willful infringement (Compl. ¶68; Prayer for Relief ¶vii).

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

  • A central issue will be one of analytical evidence: Does the specific sulfoalkyl ether cyclodextrin excipient used in Defendants’ proposed generic product meet the quantitative purity limitations recited in the asserted claims of the ’773 patent, particularly the UV absorption threshold for a "drug-degrading agent"?
  • The case will also turn on a question of claim construction: How will the court define the term "drug-degrading agent" and the precise, enforceable parameters of the UV spectrophotometry test method that is explicitly recited in the patent’s independent claims?