DCT

2:25-cv-18032

Mitsubishi Tanabe Pharma Corp v. Zydus Pharma USA Inc

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Key Events
Complaint

I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 2:25-cv-18032, D.N.J., 11/29/2025
  • Venue Allegations: Venue is alleged to be proper for Zydus USA based on its regular and established place of business in New Jersey. For the two foreign defendants, Zydus Lifesciences and Zydus Global FZE, venue is alleged to be proper in any judicial district as they are foreign corporations.
  • Core Dispute: Plaintiff alleges that Defendants' filing of an Abbreviated New Drug Application (ANDA) for a generic version of RADICAVA ORS® constitutes an act of infringement of eight U.S. patents related to oral suspensions of the drug edaravone.
  • Technical Context: The technology concerns pharmaceutical formulations of edaravone, an active ingredient for treating Amyotrophic Lateral Sclerosis (ALS), as an oral suspension, which provides a less burdensome administration route than the prior intravenous version.
  • Key Procedural History: The litigation was initiated under the Hatch-Waxman Act following Defendants' submission of ANDA No. 220849 with a Paragraph IV certification, asserting that the patents-in-suit are invalid, unenforceable, or will not be infringed. The complaint was filed within the 45-day statutory window, triggering an automatic 30-month stay on FDA approval of the ANDA. Plaintiff’s product, RADICAVA ORS®, also benefits from Orphan Drug Exclusivity (ODE) until May 12, 2029.

Case Timeline

Date Event
2018-11-02 Earliest Priority Date for ’341, ’416, ’450, ’352, ’660, and ’409 Patents
2020-11-12 Earliest Priority Date for ’025 and ’946 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 RADICAVA ORS® (NDA No. 215446) Approved by FDA
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
2025-01-14 U.S. Patent No. 12,194,025 Issues
2025-04-29 U.S. Patent No. 12,285,409 Issues
2025-05-27 U.S. Patent No. 12,310,946 Issues
2025-10-29 Date of Defendants’ Notice Letter Regarding ANDA Filing
2025-11-04 Plaintiff Receives Notice Letter
2025-11-29 Complaint for Patent Infringement Filed

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, "Edaravone Suspension for Oral Administration," issued April 27, 2021 (’341 Patent).

The Invention Explained

  • Problem Addressed: The patent addresses the burden placed on ALS patients and caregivers by the existing intravenous (IV) administration of edaravone, a therapeutic agent for the disease (’341 Patent, col. 4:65-67). Developing a stable and effective oral formulation is challenging due to factors like edaravone's susceptibility to oxidation and the potential for low bioavailability in oral dosage forms (’341 Patent, col. 6:28-31; col. 15:21-23).
  • The Patented Solution: The invention is an oral suspension containing edaravone particles, water, and a specific type of dispersant. The dispersant is key to ensuring the edaravone particles remain suspended as solid particles, which facilitates consistent dosing and redispersal after settling (’341 Patent, Abstract; col. 5:55-64). This formulation aims to provide an ALS therapeutic effect equivalent to an injection but with the convenience of oral administration (’341 Patent, col. 4:65-67).
  • Technical Importance: This technology enabled the first oral suspension of edaravone, offering a significant quality-of-life improvement for ALS patients who previously required burdensome IV infusions (Compl. ¶¶8-9).

Key Claims at a Glance

  • The complaint asserts infringement of one or more claims, including at least independent claim 1 (Compl. ¶51).
  • Independent Claim 1 requires:
    • An edaravone suspension for human oral administration, comprising:
    • water;
    • edaravone particles comprising edaravone dispersed in the water; and
    • a dispersant that maintains the edaravone particles in a solid particle state in the water;
    • wherein the amount of edaravone particles is in a range of 0.5% (w/v) to 36% (w/v); and
    • the dispersant is selected from the group of polyvinyl alcohol, methylcellulose, hypromellose, sucrose fatty acid ester, and polysorbate.
  • The complaint’s broad allegation of infringing "one or more claims" suggests the right to assert dependent claims is reserved (Compl. ¶51).

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

  • Patent Identification: U.S. Patent No. 11,241,416, "Edaravone Suspension for Oral Administration," issued February 8, 2022 (’416 Patent).

The Invention Explained

  • Problem Addressed: As a continuation of the application leading to the ’341 Patent, this patent addresses the same challenges: creating a stable, effective, and convenient oral alternative to intravenous edaravone for ALS patients (’416 Patent, col. 1:15-18).
  • The Patented Solution: The ’416 Patent claims an edaravone suspension defined by both its composition and its resulting pharmacokinetic (PK) profile in humans. The formulation includes specific concentration ranges for the edaravone particles and the dispersant, and further requires that the dispersant meets a defined physical property ("transmission scattering light intensity"). Critically, the claim requires the suspension to produce specific mean Cmax (peak plasma concentration) and AUC (total drug exposure) values when a 90-120 mg dose is orally administered (’416 Patent, col. 2:16-24; col. 4:8-11).
  • Technical Importance: This patent protects not just the recipe of the formulation but also its specific in vivo performance, creating a potentially stronger barrier to generic competitors who must demonstrate bioequivalence.

Key Claims at a Glance

  • The complaint asserts infringement of one or more claims, including at least independent claim 1 (Compl. ¶61).
  • Independent Claim 1 requires:
    • 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 0.001% (w/v) to 1.0% (w/v);
    • The blending amount of edaravone particles is 0.5% (w/v) to 36% (w/v); and
    • When a 90 to 120 mg dose is administered, the suspension exhibits a mean Cmax of 500-2500 ng/mL and a mean AUC0-∞ of 1000-2500 h*ng/mL.
  • The complaint’s phrasing suggests the right to assert dependent claims is reserved (Compl. ¶61).

Multi-Patent Capsules

  • U.S. Patent No. 11,478,450: "Edaravone Suspension for Oral Administration," issued October 25, 2022 (’450 Patent). This patent claims a method of treating ALS by administering an oral edaravone suspension containing specific ingredients, including a selected dispersant (Compl. ¶71; ’450 Patent, Claim 1). The asserted independent claim is claim 1. The accused feature is Defendants' proposed generic edaravone product, which is intended to be used for treating ALS (Compl. ¶¶43, 71).
  • U.S. Patent No. 11,826,352: "Edaravone Suspension for Oral Administration," issued November 28, 2023 (’352 Patent). This patent claims a composition for an oral edaravone suspension that includes a thickening agent and is characterized by having a specific classification (IDDSI level 1 to 3), which relates to its suitability for patients with difficulty swallowing (Compl. ¶81; ’352 Patent, Claim 1). The asserted independent claim is claim 1. The accused feature is Defendants' proposed generic copy of RADICAVA ORS® (Compl. ¶81).
  • U.S. Patent No. 11,957,660: "Edaravone Suspension for Oral Administration," issued April 16, 2024 (’660 Patent). This patent claims an edaravone suspension that notably does not contain a preservative but demonstrates no bacterial growth for at least 28 days according to a specified test, a feature related to the formulation's self-preserving nature (Compl. ¶91; ’660 Patent, Claim 1). The asserted independent claim is claim 1. The accused feature is Defendants' proposed generic product (Compl. ¶91).
  • U.S. Patent No. 12,194,025: "Pharmaceutical composition for oral administration of edaravone and method of administering same," issued January 14, 2025 (’025 Patent). This patent claims a method of treating an oxidative stress disease by administering edaravone based on specific timing relative to meals (e.g., at least 8 hours after a high-fat meal) to manage food effects on drug absorption (Compl. ¶101; ’025 Patent, Claim 1). The asserted independent claim is claim 1. Infringement is alleged based on the expected instructions for use in the label of Defendants’ proposed product (Compl. ¶101).
  • U.S. Patent No. 12,285,409: "Edaravone Suspension for Oral Administration," issued April 29, 2025 (’409 Patent). This patent claims a method of treating ALS by administering an oral edaravone suspension defined by its components and a resulting pharmacokinetic profile equivalent to an intravenous injection (Compl. ¶111; ’409 Patent, Claim 1). The asserted independent claim is claim 1. The accused feature is the proposed use of Defendants' generic product for treating ALS (Compl. ¶111).
  • U.S. Patent No. 12,310,946: "Pharmaceutical composition for oral administration of edaravone and method of administering same," issued May 27, 2025 (’946 Patent). Similar to the ’025 patent, this patent claims a method of treating amyotrophic lateral sclerosis by administering edaravone within specific time intervals after consumption of different types of meals (e.g., high-fat, low-fat) (Compl. ¶121; ’946 Patent, Claim 1). The asserted independent claim is claim 1. Infringement is alleged based on the anticipated label instructions for Defendants' product (Compl. ¶121).

III. The Accused Instrumentality

Product Identification

The accused instrumentality is Defendants’ proposed generic edaravone oral suspension, which is the subject of Abbreviated New Drug Application (ANDA) No. 220849 submitted to the FDA (Compl. ¶2).

Functionality and Market Context

The product is an oral suspension formulated at a concentration of 105 mg of edaravone per 5 mL and is intended to be a generic equivalent to Plaintiff's RADICAVA ORS® (Compl. ¶41). As a generic copy, it is designed to have the same active ingredient, dosage form, strength, and route of administration as the branded product it references (Compl. ¶43). It is intended for the treatment of ALS, a rare and fatal neurodegenerative disease for which there are few approved therapies (Compl. ¶¶3, 5).

IV. Analysis of Infringement Allegations

The complaint alleges infringement under 35 U.S.C. § 271(e)(2), which defines the submission of an ANDA seeking approval to market a generic drug before patent expiration as a statutory act of infringement. The core allegation is that the product described in Zydus's ANDA, being a "generic copy" of RADICAVA ORS®, will necessarily meet the limitations of the asserted claims upon approval and commercialization (Compl. ¶¶43, 51, 61). No probative visual evidence provided in complaint.

’341 Patent Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
An edaravone suspension for human oral administration, comprising: water; edaravone particles...dispersed in the water... Defendants' ANDA product is alleged to be an oral suspension of edaravone intended for human use. ¶¶50-51 col. 4:63-65
a dispersant dispersing the edaravone particles in water such that the dispersant maintains the edaravone particles in a solid particle state in the water... As a generic copy, Defendants' suspension is alleged to contain a dispersant that performs the claimed function. ¶51 col. 5:55-58
wherein a blending amount of the edaravone particles is in a range of 0.5% (w/v) to 36% (w/v)... Defendants' product is alleged to have an edaravone concentration (105 mg/5mL or 2.1% w/v) that falls within the claimed range. ¶¶41, 51 col. 26:14-16
and the dispersant is at least one dispersant selected from the group consisting of polyvinyl alcohol, methylcellulose, hypromellose, sucrose fatty acid ester and polysorbate. Defendants' product is alleged to contain one of the listed dispersants to achieve bioequivalence with the reference listed drug. ¶51 col. 26:17-20

’416 Patent Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
a dispersant exhibiting a transmission scattering light intensity of 1% or more... Defendants' suspension is alleged to contain a dispersant that meets the claimed physical property. ¶61 col. 4:8-11
wherein a blending amount of the dispersant is in a range of 0.001% (w/v) to 1.0% (w/v)... Defendants' product is alleged to contain a dispersant concentration within the claimed range. ¶61 col. 5:10-13
and when edaravone in the edaravone suspension is in a range of 90 to 120 mg...exhibits a mean Cmax...and a mean AUC... As a bioequivalent generic, Defendants' product is alleged to produce a pharmacokinetic profile that meets the claimed parameters. ¶61 col. 2:16-24
  • Identified Points of Contention:
    • Scope Questions: A central question will be whether Defendants’ formulation uses one of the specific dispersants recited in Claim 1 of the ’341 Patent. If Defendants use a different, unlisted excipient, they may argue non-infringement, raising the question of whether that excipient is an equivalent. For the concentration and PK profile limitations in both patents, the dispute will focus on whether the parameters of the ANDA product fall within the claimed ranges.
    • Technical Questions: Since the complaint lacks specific details on Defendants' formulation, a key question is what evidence exists within the ANDA to demonstrate that the proposed product meets each claim element. For the '416 Patent, a dispute may arise over whether Zydus's product, tested under the specific conditions outlined in the patent, actually exhibits a "transmission scattering light intensity of 1% or more."

V. Key Claim Terms for Construction

  • The Term: "dispersant" (from ’341 Patent, Claim 1)

  • Context and Importance: The identity of the "dispersant" is critical because Claim 1 of the ’341 Patent limits this term to a specific list of five chemical classes. The infringement analysis will turn on whether the excipient used in Zydus’s product falls within the scope of one of these classes.

  • Intrinsic Evidence for Interpretation:

    • Evidence for a Broader Interpretation: The specification describes the function of the dispersant broadly, stating it "allows the edaravone particles to be well dispersed in water" (’341 Patent, col. 5:61-62). Plaintiff may argue that any excipient from the listed classes that performs this function is covered.
    • Evidence for a Narrower Interpretation: Defendants may argue the scope should be limited by the specific examples and preferred embodiments in the specification, such as polyvinyl alcohol with a particular saponification degree and kinematic viscosity (’341 Patent, col. 5:65-col. 6:2).

  • The Term: "maintains the edaravone particles in a solid particle state" (from ’341 Patent, Claim 1)

  • Context and Importance: This functional language is central to the claimed invention's stability. Practitioners may focus on this term because its definition will determine the required level of performance for an accused dispersant. A dispute could arise over whether this requires preventing any dissolution over a period of time or merely preventing complete dissolution.

  • Intrinsic Evidence for Interpretation:

    • Evidence for a Broader Interpretation: The patent's summary describes the invention as a "suspension" that "reduces burden on ALS patients" (’341 Patent, col. 4:63-67), suggesting the term should be interpreted practically in light of the invention's overall purpose rather than requiring absolute stability.
    • Evidence for a Narrower Interpretation: The specification contrasts the suspension with solutions where edaravone is dissolved, noting the low solubility of edaravone in water (’341 Patent, col. 15:48-51). A defendant could argue this language supports a narrow construction that requires a high degree of insolubility and stability against dissolution, for which specific tests might be necessary.

VI. Other Allegations

  • Indirect Infringement: The complaint alleges inducement and contributory infringement, asserting that upon FDA approval, Defendants' commercial activities will cause infringement by others (e.g., patients and physicians) (Compl. ¶¶54, 57). For the asserted method-of-use patents, this theory is central, as it relies on the allegation that Defendants' product label will instruct users to administer the drug in an infringing manner.
  • Willful Infringement: While the complaint does not use the word "willful," it alleges that Defendants had "actual and constructive notice" of the patents-in-suit prior to filing the ANDA, presumably through their listing in the FDA's Orange Book (Compl. ¶55). The prayer for relief requests a finding that the case is "exceptional" and an award of attorneys' fees, which is consistent with an intent to pursue a claim for enhanced damages based on willful or egregious conduct (Compl. Prayer for Relief ¶E).

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

  • A core issue will be one of compositional identity: Does the formulation detailed in Zydus’s confidential ANDA submission contain an excipient that falls within the closed list of "dispersants" recited in Claim 1 of the '341 Patent, and are its component concentrations within the claimed ranges, or has Zydus designed a formulation that achieves bioequivalence with different components?
  • A key evidentiary question will be one of functional performance: For claims with quantitative or performance-based limitations (e.g., the pharmacokinetic profile in the '416 Patent, the stability requirement in the '660 patent, or the dysphagia-related viscosity in the '352 patent), does the evidence show that Zydus’s product actually meets these specific, testable metrics?
  • A central question for the method-of-use patents will be one of induced infringement: Will the language of Zydus’s proposed product label be construed by the court as actively encouraging or instructing physicians and patients to administer the drug under the specific meal-timing conditions claimed in patents like the ’025 and ’946 Patents?