DCT

2:25-cv-03326

Mitsubishi Tanabe Pharma Corp v. Shanghai Auzone Biological Technology Co Ltd

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I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 2:25-cv-03326, D.N.J., 04/25/2025
  • Venue Allegations: Venue is alleged to be proper on the basis that the non-U.S. defendants are foreign corporations that may be sued in any judicial district, and that the U.S. defendant has a regular and established place of business in New Jersey.
  • Core Dispute: Plaintiff alleges that Defendants’ submission of a New Drug Application for a generic edaravone product infringes five patents related to oral suspension formulations for treating Amyotrophic Lateral Sclerosis.
  • Technical Context: The technology concerns oral suspension formulations of edaravone, an active pharmaceutical ingredient used to treat Amyotrophic Lateral Sclerosis (ALS), a fatal neurodegenerative disease, offering a less burdensome alternative to intravenous administration.
  • Key Procedural History: This patent infringement action was initiated under the Hatch-Waxman Act, triggered by Defendants' submission of a 505(b)(2) New Drug Application (NDA No. 219846) seeking FDA approval for their AUKONTALS edaravone product. The NDA included a Paragraph IV certification alleging non-infringement of Plaintiff's patents, which are listed in the FDA's Orange Book for Plaintiff's approved drug, RADICAVA ORS®. Plaintiff asserts it filed this complaint within the 45-day statutory window after receiving Defendants' notice letter, thus triggering a 30-month stay of FDA approval for Defendants' product. Plaintiff’s RADICAVA ORS® also benefits from Orphan Drug Exclusivity, set to expire in May 2029.

Case Timeline

Date Event
2018-11-02 Priority Date for ’341, ’416, ’450, ’352, and ’660 Patents
2021-04-27 U.S. Patent No. 10,987,341 Issues
2022-02-08 U.S. Patent No. 11,241,416 Issues
2022-05-12 Plaintiff's RADICAVA ORS® receives FDA approval
2022-10-25 U.S. Patent No. 11,478,450 Issues
2023-11-28 U.S. Patent No. 11,826,352 Issues
2024-03-28 Orphan Drug Exclusivity granted for RADICAVA ORS®
2024-04-16 U.S. Patent No. 11,957,660 Issues
2025-03-13 Defendants send "Non-Infringement Analysis Report" to Plaintiff
2025-03-16 Plaintiff receives Defendants' Notice Letter
2025-04-22 Plaintiff receives access to redacted portions of Defendants' NDA
2025-04-25 Complaint Filed
2029-05-12 Orphan Drug Exclusivity for RADICAVA ORS® expires

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

U.S. Patent No. 10,987,341 - "Edaravone Suspension for Oral Administration"

  • Patent Identification: U.S. Patent No. 10,987,341, titled “Edaravone Suspension for Oral Administration,” issued on April 27, 2021 (Compl. ¶33).

The Invention Explained

  • Problem Addressed: The patent addresses the challenge of administering edaravone, a therapeutic agent for Amyotrophic Lateral Sclerosis (ALS). Historically provided as an injection, this method is burdensome for patients with progressing motor neuron disease and their caregivers (’341 Patent, col. 4:64-67). Creating an oral drug that is biologically equivalent to an injection is described as difficult due to factors like gastrointestinal absorption and first-pass metabolism (’341 Patent, col. 15:12-22).
  • The Patented Solution: The invention is an oral suspension containing edaravone particles, water, and a specific dispersant. The dispersant is crucial for keeping the solid edaravone particles uniformly suspended in the liquid, which is intended to ensure consistent dosing and achieve bioavailability comparable to an intravenous infusion (’341 Patent, Abstract; col. 4:64-67). The patent's single figure illustrates that the oral suspension (PO) can achieve a plasma concentration profile similar to that of an intravenous (IV) administration (’341 Patent, FIG. 1).
  • Technical Importance: This technology offers a method to deliver a critical ALS therapy via a less invasive and more convenient oral route, potentially improving patient quality of life without sacrificing therapeutic effect (’341 Patent, col. 15:12-16).

Key Claims at a Glance

  • The complaint asserts at least Independent Claim 1 (Compl. ¶50).
  • Essential elements of Independent Claim 1 include:
    • An edaravone suspension for human oral administration;
    • Comprising water, edaravone particles dispersed in the water, and a dispersant;
    • The dispersant maintains the edaravone particles in a solid state in the water;
    • The blending amount of edaravone particles is between 0.5% (w/v) and 36% (w/v); and
    • The dispersant is selected from the group of polyvinyl alcohol, methylcellulose, hypromellose, sucrose fatty acid ester, and polysorbate.
  • The complaint alleges infringement of "one or more claims," which may suggest an intent to assert dependent claims later in the litigation (Compl. ¶50).

U.S. Patent No. 11,241,416 - "Edaravone Suspension for Oral Administration"

  • Patent Identification: U.S. Patent No. 11,241,416, titled “Edaravone Suspension for Oral Administration,” issued on February 8, 2022 (Compl. ¶34).

The Invention Explained

  • Problem Addressed: As with the parent '341 Patent, this patent aims to solve the problem of burdensome intravenous administration of edaravone for ALS patients by creating a bioequivalent oral alternative (’416 Patent, col. 4:60-63).
  • The Patented Solution: This patent also claims an oral suspension of edaravone. However, its independent claim defines the dispersant by a specific physical property rather than solely by its chemical identity. The claim requires a dispersant "exhibiting a transmission scattering light intensity of 1% or more," a characteristic the specification links to the ability to form a stable and effective suspension (’416 Patent, col. 4:5-18, col. 12:51-57). This functional limitation aims to capture any agent that can successfully suspend the edaravone particles, regardless of its specific chemical name, so long as it meets the claimed performance metric.
  • Technical Importance: The invention provides an alternative, performance-based definition for a key component of an oral edaravone formulation, broadening the patent's potential scope beyond a fixed list of chemical dispersants.

Key Claims at a Glance

  • The complaint asserts at least Independent Claim 1 (Compl. ¶60).
  • Essential elements of Independent Claim 1 include:
    • An edaravone suspension for human oral administration;
    • Comprising water, edaravone particles, and a dispersant;
    • The dispersant exhibits a transmission scattering light intensity of 1% or more;
    • The blending amount of the dispersant is between 0.001% (w/v) and 1.0% (w/v); and
    • The blending amount of the edaravone particles is between 0.5% (w/v) and 36% (w/v).
  • The complaint alleges infringement of "one or more claims" of the ’416 Patent (Compl. ¶60).

U.S. Patent No. 11,478,450 - "Edaravone Suspension for Oral Administration"

  • Patent Identification: U.S. Patent No. 11,478,450, titled “Edaravone Suspension for Oral Administration,” issued October 25, 2022 (Compl. ¶35).
  • Technology Synopsis: This patent claims a method of treating ALS by administering an oral edaravone formulation. The claims focus on the dosing regimen (daily or intermittent) and resulting pharmacokinetic profiles (e.g., Cmax and AUC) that are therapeutically effective (’450 Patent, Abstract; col. 27:5-20).
  • Asserted Claims: The complaint asserts at least Independent Claim 1 (Compl. ¶70).
  • Accused Features: The accused features are the proposed use and dosing instructions for the AUKONTALS product, which are alleged to meet the claimed method steps and achieve the claimed pharmacokinetic outcomes (Compl. ¶69-70).

U.S. Patent No. 11,826,352 - "Edaravone Suspension for Oral Administration"

  • Patent Identification: U.S. Patent No. 11,826,352, titled “Edaravone Suspension for Oral Administration,” issued November 28, 2023 (Compl. ¶36).
  • Technology Synopsis: This patent claims an edaravone suspension that includes a "thickening agent" to achieve a specific viscosity level, defined by an International Dysphagia Diet Standardisation Initiative (IDDSI) level between 1 and 3. This is intended to make the suspension easier for patients with swallowing difficulties (dysphagia) to consume safely (’352 Patent, Abstract; col. 5:48-56).
  • Asserted Claims: The complaint asserts at least Independent Claim 1 (Compl. ¶80).
  • Accused Features: The AUKONTALS product is alleged to contain a thickening agent and have a viscosity that falls within the claimed ranges (Compl. ¶79-80).

U.S. Patent No. 11,957,660 - "Edaravone Suspension for Oral Administration"

  • Patent Identification: U.S. Patent No. 11,957,660, titled “Edaravone Suspension for Oral Administration,” issued April 16, 2024 (Compl. ¶37).
  • Technology Synopsis: This patent claims an edaravone suspension that specifically "does not contain a preservative" from a list of common preservatives, yet is formulated to resist bacterial growth for at least 28 days per a standard pharmaceutical test. This combination of being preservative-free while remaining shelf-stable is the purported inventive concept (’660 Patent, col. 7:17-24; Claim 1).
  • Asserted Claims: The complaint asserts at least Independent Claim 1 (Compl. ¶90).
  • Accused Features: The AUKONTALS product is alleged to be formulated without the specified preservatives while still meeting the claimed standard for resisting bacterial growth (Compl. ¶89-90).

III. The Accused Instrumentality

Product Identification

  • The accused product is AUKONTALS, a proposed drug for which Defendants have filed 505(b)(2) NDA No. 219846 with the FDA (Compl. ¶18).

Functionality and Market Context

  • AUKONTALS is identified as an "edaravone product for the treatment of ALS" (Compl. ¶18). The complaint alleges that Defendants' NDA seeks approval for a product containing "90 milligrams (3 x 30 milligram tablets) of edaravone" (Compl. ¶39). The complaint provides no further detail on the product's specific formulation or whether the tablets are intended to be reconstituted into a suspension prior to administration. The product is positioned as a generic alternative to Plaintiff's RADICAVA ORS®, which is designated as the Reference Labeled Drug in Defendants' NDA (Compl. ¶18, ¶40). Defendants intend to manufacture, market, and sell AUKONTALS in the United States upon receiving FDA approval (Compl. ¶21).
  • No probative visual evidence provided in complaint.

IV. Analysis of Infringement Allegations

The complaint alleges infringement on "information and belief" but does not contain or reference a claim chart, nor does it plead specific facts mapping elements of the accused product to the patent claims. The following chart summarizes the allegations for the lead patent based on the complaint's general assertions.

10,987,341 Patent Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
An edaravone suspension for human oral administration... The complaint alleges the AUKONTALS product is an edaravone product for oral administration that infringes the patent. ¶18, ¶50 col. 25:35-37
comprising water; edaravone particles...dispersed in the water; and a dispersant... The complaint does not identify specific excipients but alleges infringement, thereby implying the presence of these required components. ¶50 col. 25:38-44
wherein a blending amount of the edaravone particles is in a range of 0.5% (w/v) to 36% (w/v) The specific concentration of edaravone in the accused product is not detailed, but the complaint alleges it will meet this limitation. ¶50 col. 25:45-47
and the dispersant is at least one dispersant selected from the group consisting of polyvinyl alcohol, methylcellulose, hypromellose, sucrose fatty acid ester and polysorbate. The specific dispersant is not identified, but the complaint alleges the accused product will contain a dispersant from this claimed group. ¶50 col. 25:47-51
  • Identified Points of Contention:
    • Scope Questions: A primary question may arise from the complaint's description of the accused product as containing "tablets" (Compl. ¶39), whereas the patent claims a "suspension." The resolution may depend on whether the product's label instructs users to reconstitute the tablets in a liquid to form a suspension prior to administration, and at what point infringement is deemed to occur.
    • Technical Questions: The complaint does not provide factual support identifying the specific dispersant used in AUKONTALS or its concentration. A central technical question will be whether discovery reveals that the accused product's formulation meets the specific compositional and concentration requirements of Claim 1.

11,241,416 Patent Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
An edaravone suspension for human oral administration... The complaint alleges the AUKONTALS product is an edaravone product for oral administration that infringes the patent. ¶18, ¶60 col. 27:14-16
a dispersant exhibiting a transmission scattering light intensity of 1% or more... The complaint does not provide data on the physical properties of the excipients but alleges infringement, implying the dispersant meets this functional limitation. ¶60 col. 27:19-21
wherein a blending amount of the dispersant is in a range of 0.001% (w/v) to 1.0% (w/v) The complaint does not specify the dispersant concentration but alleges the infringing product will fall within this range. ¶60 col. 27:25-27
  • Identified Points of Contention:
    • Technical Questions: The claim requires the dispersant to meet a specific, measurable physical property ("transmission scattering light intensity of 1% or more"). A key question will be whether the dispersant in the AUKONTALS product, once identified through discovery, actually exhibits this property under the test conditions described in the patent.
    • Scope Questions: As described for the ’341 Patent, the "tablet" versus "suspension" distinction will be a central issue for the court to resolve.

V. Key Claim Terms for Construction

  • The Term: "edaravone suspension"

    • Context and Importance: This term appears in the preamble of the asserted independent claims of all five patents-in-suit. Its construction is critical because the complaint describes the accused product as containing "tablets" (Compl. ¶39), which on its face differs from a "suspension." The outcome of the case may depend on whether the accused product's dosage form falls within the scope of this term.
    • Intrinsic Evidence for Interpretation:
      • Evidence for a Broader Interpretation: The specification describes preparing the suspension by mixing solid "edaravone particles" with water containing a dispersant (’341 Patent, col. 9:1-19). This could support an argument that a product supplied as a tablet but intended for reconstitution in water before administration results in an infringing "suspension" at the moment of use.
      • Evidence for a Narrower Interpretation: The patent's abstract describes "[a]n edaravone suspension" as the invention, and the detailed description consistently refers to the final drug product as a liquid suspension, not a solid to be reconstituted (’341 Patent, Abstract; col. 4:64-65). This may support an argument that the claimed invention is a pre-formulated liquid product, not a kit of a solid and a liquid or a solid meant for reconstitution.

  • The Term: "dispersant"

    • Context and Importance: This term is a central element of the composition claims of the ’341 and ’416 patents. The ’341 patent requires the dispersant to be from a specific Markush group, while the ’416 patent requires it to have a specific physical property. The definition of what constitutes a "dispersant" will be key to determining if the excipients in the accused product meet these limitations.
    • Intrinsic Evidence for Interpretation:
      • Evidence for a Broader Interpretation: The specification provides a functional definition, stating a dispersant is any agent that "allows the edaravone particles to be well dispersed in water without causing the edaravone particles to form secondary agglomerates" (’341 Patent, col. 5:63-67). This suggests that any excipient performing this function could be considered a dispersant.
      • Evidence for a Narrower Interpretation: The patent provides a list of specific examples of dispersants, such as polyvinyl alcohol and methylcellulose (’341 Patent, col. 25:49-51). This could support a narrower construction limited to agents whose primary purpose and function in the pharmaceutical arts is dispersion, rather than any multi-purpose excipient that may have an incidental dispersing effect.

VI. Other Allegations

  • Indirect Infringement: The complaint makes general allegations that upon FDA approval, Defendants' commercial activities will induce and contribute to infringement by others in the United States (e.g., Compl. ¶53, ¶56). No specific facts, such as citations to product labeling or user instructions, are provided to support the knowledge and intent elements of these claims.
  • Willful Infringement: The complaint does not contain a formal count for willful infringement. However, it alleges that Defendants had "actual and constructive notice" of each patent prior to filing their NDA (e.g., Compl. ¶54, ¶64). These allegations may form the basis for a later claim of willfulness or a request for enhanced damages, and they support the complaint's prayer for attorneys' fees in an "exceptional case" under 35 U.S.C. § 285 (Prayer ¶E).

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

  • A central issue will be one of definitional scope: can the term "suspension," which is central to all asserted patents, be construed to cover a product that the complaint identifies as containing "tablets"? The resolution will likely depend on the product's final administered form as dictated by its label and instructions for use.
  • A key evidentiary question will be one of compositional and functional identity: does the specific formulation of the AUKONTALS product, once revealed, contain components that meet the claimed limitations, including a dispersant from the required chemical group (’341 patent) that also exhibits the specific physical properties (’416 patent) and a thickening agent that provides the required viscosity (’352 patent)?
  • A third question concerns preservation: does the accused product practice the claimed invention of the ’660 patent by being formulated without specific preservatives while also being able to resist bacterial growth as required by the claim? This will likely require technical evidence and expert testimony regarding both the product's composition and its performance in stability testing.