DCT

1:25-cv-00929

Mitsubishi Tanabe Pharma Corp v. Cipla USA Inc

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I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 1:25-cv-00929, D. Del., 07/24/2025
  • Venue Allegations: Plaintiff alleges venue is proper in Delaware because Defendant Cipla USA, Inc. is a Delaware corporation, and its parent, Cipla Limited, purposefully avails itself of the district by directing its U.S. subsidiary, deriving revenue from sales in Delaware, and intending to market the accused product there.
  • Core Dispute: Plaintiff alleges that Defendants' submission of an Abbreviated New Drug Application (ANDA) to the FDA for a generic version of Plaintiff's drug, RADICAVA ORS®, constitutes an act of infringement of a patent covering an oral suspension of the active ingredient edaravone.
  • Technical Context: The technology concerns pharmaceutical formulations for treating Amyotrophic Lateral Sclerosis (ALS), a fatal neurodegenerative disease, by providing the drug edaravone in an oral suspension to improve patient convenience over intravenous administration.
  • Key Procedural History: This action arises under the Hatch-Waxman Act and was triggered by Defendants' "Paragraph IV" certification notice letter dated June 9, 2025. The complaint notes that this is the third lawsuit filed by the Plaintiff against the Defendants concerning the same ANDA (No. 218428), with the prior actions asserting different patents. The patent-in-suit is listed in the FDA's Orange Book for Plaintiff's branded product, RADICAVA ORS®, and is subject to a terminal disclaimer. Plaintiff's product has also been granted orphan drug exclusivity by the FDA, set to expire in May 2029.

Case Timeline

Date Event
2018-11-02 ’409 Patent Priority Date
2022-05-12 FDA grants approval for RADICAVA ORS® (NDA No. 215446)
2023-05-30 Cipla sends First Notice Letter for other patents
2023-07-12 Plaintiff files "First Suit" against Cipla
2023-12-21 Cipla sends Second Notice Letter for other patents
2024-03-28 FDA grants orphan drug exclusivity for RADICAVA ORS®
2024-08-30 Plaintiff files Amended Complaint in First Suit
2025-02-18 Cipla sends Third Notice Letter for other patents
2025-04-29 U.S. Patent No. 12,285,409 ('409 Patent) Issues
2025-06-09 Cipla sends Fourth Notice Letter concerning the ’409 Patent
2025-07-24 Complaint Filed

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

U.S. Patent No. 12,285,409 - “Edaravone Suspension for Oral Administration”

The Invention Explained

  • Problem Addressed: The patent addresses the challenge of administering the drug edaravone, a therapeutic agent for ALS. Administration via injection is burdensome for patients and caregivers, but creating an oral drug product with bioavailability comparable to an injection is difficult due to factors like absorption from the gastrointestinal tract (’409 Patent, col. 27:36-54).
  • The Patented Solution: The invention is an oral suspension that uses a specific combination of components to solve this problem. It comprises edaravone particles of a defined size range, dispersed in water with a "dispersant" that keeps the drug particles in a solid state (’409 Patent, col. 6:9-11). This formulation is designed to be easily swallowed while achieving specific pharmacokinetic (PK) results in the body—namely, a concentration peak (Cmax) and total exposure (AUC) that demonstrate its effectiveness, as illustrated in the patent's FIGURE showing PK profiles (’409 Patent, col. 6:22-29, Fig. 1).
  • Technical Importance: Developing a stable oral suspension that achieves bioavailability comparable to an intravenous infusion represents a significant improvement in the quality of life for ALS patients by enabling at-home administration and reducing the burden of care (Compl. ¶13-14).

Key Claims at a Glance

  • The complaint makes general allegations against "one or more claims" without specifying them (Compl. ¶52). Independent claim 1 is the broadest claim and is analyzed here.
  • Independent Claim 1:
    • An edaravone suspension for human oral administration, comprising: water;
    • Edaravone particles comprising edaravone and dispersed in the water;
    • A dispersant that maintains the edaravone particles in a solid particle state in the water;
    • Wherein the particles have a D50 particle size of 10-100 µm and a D90 particle size of 50-300 µm;
    • Wherein the blending amount of edaravone particles is 0.2% to 36% (w/v); and
    • Wherein a 90-120 mg dose exhibits a mean Cmax of 500-2500 ng/mL and a mean AUC0-∞ of 1000-2500 h*ng/mL when orally administered to a human.
  • The complaint implicitly reserves the right to assert other claims, including dependent claims (Compl. ¶55).

III. The Accused Instrumentality

Product Identification

The accused instrumentality is Defendants' proposed generic edaravone oral suspension, for which Cipla Limited filed Abbreviated New Drug Application (ANDA) No. 218428 with the U.S. Food and Drug Administration (Compl. ¶24, ¶45).

Functionality and Market Context

The complaint alleges the accused product is an oral suspension containing 105 milligrams of edaravone per 5 mL dose (Compl. ¶43). It is designed to be a generic equivalent of MTPC’s branded product, RADICAVA ORS®, and is indicated for the treatment of ALS (Compl. ¶44-45). The filing of the ANDA is an assertion by Cipla that its product is bioequivalent to RADICAVA ORS® (Compl. ¶44).

IV. Analysis of Infringement Allegations

The complaint does not contain a claim chart or detailed infringement contentions, instead alleging generally that the product described in ANDA No. 218428 meets all elements of at least one claim of the ’409 Patent (Compl. ¶55). The core infringement allegations are based on the statutory act of filing the ANDA under 35 U.S.C. § 271(e)(2) (Compl. ¶53). No probative visual evidence provided in complaint.

’409 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 comprising edaravone and dispersed in the water; and a dispersant...maintains the edaravone particles in a solid particle state... The complaint identifies the accused product as an "edaravone oral suspension" for which Defendants seek FDA approval via ANDA No. 218428. ¶43, ¶45 col. 29:15-22
wherein the edaravone particles in the suspension have a D50 particle size in a range of 10 µm to 100 µm and a D90 particle size of in a range of 50 µm to 300 µm... The complaint does not provide specific details on particle size but alleges that the proposed generic product "meets all elements of one or more claims of the ’409 patent." ¶55 col. 29:23-26
a blending amount of the edaravone particles is in a range of 0.2% (w/v) to 36% (w/v)... The accused product is alleged to contain 105 mg of edaravone per 5 mL, which corresponds to a concentration of 2.1% (w/v), a value that falls within the claimed range. ¶43 col. 29:23-26
when edaravone...is in a range of 90 to 120 mg, edaravone in a plasma exhibits a mean Cmax in a range of 500 to 2500 ng/ml and a mean AUC0-∞ in a range of 1000 to 2500 h*ng/mL when...orally administered to a human. The accused product's alleged dosage of 105 mg per 5 mL falls within the claimed dosage range. The filing of the ANDA implies an assertion of bioequivalence, which would form the basis for alleging this PK profile is met. ¶43, ¶44 col. 29:27-33

Identified Points of Contention

  • Technical Questions: A key factual question will be whether the specific formulation detailed in Cipla's confidential ANDA submission meets the precise numerical ranges for particle size distribution (D50 and D90) required by the claims.
  • Scope Questions: The case may raise questions about the scope of the pharmacokinetic (PK) limitations. For example, does the data in Cipla's ANDA demonstrate that its product, when administered, actually produces a Cmax and AUC profile that falls within the ranges recited in the claim? Infringement of these "product-by-result" limitations will depend entirely on the evidence of the accused product's performance.

V. Key Claim Terms for Construction

The complaint does not provide sufficient detail for a full analysis of claim construction disputes. However, based on the claim language, practitioners may focus on the following terms.

  • The Term: "dispersant dispersing the edaravone particles...such that the dispersant maintains the edaravone particles in a solid particle state"

  • Context and Importance: This term is critical because it defines a key excipient not just by its identity (e.g., polyvinyl alcohol) but by its function. The dispute will likely center on what evidence is required to prove that a given substance performs this specific function of maintaining the solid state, as opposed to merely aiding dispersion generally.

  • Intrinsic Evidence for Interpretation:

    • Evidence for a Broader Interpretation: A party might argue the term should be read broadly to include any listed dispersant in the patent, such as polyvinyl alcohol or sucrose fatty acid ester, that is known to help suspend particles in a liquid (’409 Patent, col. 7:41-43).
    • Evidence for a Narrower Interpretation: The patent provides specific functional tests, such as "transmission scattering light intensity" and "contact angle," to identify suitable dispersants (’409 Patent, col. 7:12-14, col. 7:44-51). A party could argue the term is limited to substances that would meet the criteria of these specific tests.

  • The Term: "mean Cmax" and "mean AUC0-∞"

  • Context and Importance: These pharmacokinetic parameters define the invention by the results it achieves in the human body. The construction of these terms will determine how infringement is measured. A dispute could arise over the statistical methods, patient populations, or testing conditions required to establish the "mean" values and whether they fall within the claimed numerical ranges.

  • Intrinsic Evidence for Interpretation:

    • Evidence for a Broader Interpretation: A party may argue that as long as standard bioequivalence testing shows values falling within the claimed numerical ranges, the limitation is met, regardless of minor variations in methodology.
    • Evidence for a Narrower Interpretation: The patent discloses specific clinical study results, including a study of 42 subjects and comparison to an intravenous injection (’409 Patent, Table 10, col. 26:1-33). A party could argue that these details narrow the scope of the claim or the context in which the "mean" values must be interpreted.

VI. Other Allegations

  • Indirect Infringement: The complaint alleges that upon FDA approval, Defendants will induce and contribute to infringement by commercially manufacturing and selling the accused product (Compl. ¶60). This allegation is based on the premise that the product's labeling will instruct physicians and patients to use the generic drug in a manner covered by the patent claims.
  • Willful Infringement: The complaint alleges that Defendants had "actual and constructive notice" of the ’409 Patent prior to filing their ANDA, yet proceeded "without adequate justification" (Compl. ¶57-58). Plaintiff requests a declaration that the case is "exceptional" and an award of attorneys' fees under 35 U.S.C. § 285, which is the statutory basis for seeking enhanced damages for willful or egregious conduct (Compl., Prayer for Relief ¶E).

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

  • A central issue will be one of characterization and proof: will the specific formulation described in Cipla's confidential ANDA submission be proven to meet the quantitative limitations of the asserted claims, particularly the particle size distribution (D50/D90) and the in-vivo pharmacokinetic profile (Cmax/AUC)? The outcome will depend on the data contained within the ANDA.
  • The case may also turn on the scope of functional limitations: how will the court construe the term "dispersant" based on its claimed function of "maintain[ing] the edaravone particles in a solid particle state," and how will it treat the pharmacokinetic parameters, which define the invention by the result it produces rather than solely by its physical composition?
  • A key evidentiary question will be one of bioequivalence: does the data from Defendants' bioequivalence studies, which are central to any ANDA filing, demonstrate infringement of the patent's pharmacokinetic claims, or does it provide a basis for a non-infringement argument that the accused product falls outside the claimed performance ranges?