DCT

1:24-cv-00626

Pfizer Inc v. Rubicon Research Private Ltd

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I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 1:24-cv-00626, D. Del., 05/23/2024
  • Venue Allegations: Venue is alleged to be proper because the defendant, Rubicon, is not a resident of the United States and may therefore be sued in any judicial district.
  • Core Dispute: Plaintiff alleges that Defendant's submission of an Abbreviated New Drug Application (ANDA) seeking to market a generic version of Plaintiff's NURTEC ODT® (rimegepant sulfate) constitutes an act of infringement of a patent covering a specific formulation of the drug.
  • Technical Context: The technology concerns pharmaceutical formulations for treating CGRP-related disorders, such as migraines, using the active ingredient rimegepant in an orally disintegrating dosage form.
  • Key Procedural History: This action was initiated under the Hatch-Waxman Act following Defendant's submission of ANDA No. 219440 to the FDA. The lawsuit was triggered by a Paragraph IV Notice Letter, dated April 10, 2024, in which Defendant certified that its proposed generic product would not infringe, or that the patent-in-suit is invalid or unenforceable. The complaint was filed within the 45-day statutory period, which imposes a 30-month stay on FDA approval of the ANDA. The patent-in-suit is listed in the FDA's "Orange Book" for NURTEC ODT®. The patent includes a terminal disclaimer.

Case Timeline

Date Event
2018-03-25 U.S. Patent No. 11,083,724 Priority Date
2021-08-10 U.S. Patent No. 11,083,724 Issue Date
2024-04-10 Defendant's Paragraph IV Notice Letter Sent
2024-05-23 Complaint Filing Date

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

U.S. Patent No. 11,083,724 - "Rimegepant for CGRP Related Disorders"

  • Patent Identification: U.S. Patent No. 11,083,724, “Rimegepant for CGRP Related Disorders,” issued August 10, 2021.

The Invention Explained

  • Problem Addressed: The patent background describes migraine as a widespread, debilitating disorder and notes that existing treatments, particularly triptans, have significant limitations for many patients (Compl. ¶7; ’724 Patent, col. 2:22-50). These limitations include incomplete efficacy, headache recurrence, and contraindications for patients with or at risk for cardiovascular disease, creating a substantial "unmet medical need" for alternative therapies (’724 Patent, col. 2:40-50).
  • The Patented Solution: The invention is directed to treating CGRP-related disorders by administering rimegepant, a CGRP receptor antagonist (’724 Patent, Abstract). The claims are not directed to the rimegepant compound itself, but to a specific pharmaceutical formulation: an "oral solid molded fast-dispersing dosage form" (’724 Patent, col. 39:26-31). This formulation is designed to disintegrate or disperse rapidly (e.g., 1-60 seconds) upon contact with saliva, which may be advantageous for migraine sufferers who often experience nausea and aversion to swallowing conventional tablets (’724 Patent, col. 2:59-62; col. 10:1-6). The detailed description indicates this form is created by "subliming solvent from a composition in the solid state," a process also known as freeze-drying or lyophilization (’724 Patent, col. 10:11-17).
  • Technical Importance: This technology offers a way to deliver a non-triptan migraine therapy in a patient-friendly dosage form that may enhance ease of use and potentially speed the onset of relief (’724 Patent, col. 2:51-58).

Key Claims at a Glance

  • The complaint identifies Claim 1 as an exemplary asserted claim (Compl. ¶24).
  • Independent Claim 1 of the ’724 Patent recites:
    • A pharmaceutical composition comprising a pharmaceutically acceptable carrier and a therapeutically effective amount of a CGRP receptor antagonist, or a pharmaceutically acceptable salt thereof,
    • wherein the pharmaceutical composition is in a form of an oral solid molded fast-dispersing dosage form.
  • The complaint reserves the right to assert other claims of the ’724 Patent (Compl. ¶21).

III. The Accused Instrumentality

Product Identification

  • The accused instrumentality is "Rubicon's ANDA Product," a generic version of NURTEC ODT® (rimegepant sulfate) for which Rubicon seeks FDA approval via ANDA No. 219440 (Compl. ¶¶ 1, 9).

Functionality and Market Context

  • The complaint alleges that Rubicon's ANDA Product is a generic copy of Pfizer's branded NURTEC ODT® and is intended for the same indications: the acute and preventive treatment of migraine (Compl. ¶¶ 7, 10). Based on the infringement allegations, the ANDA Product is a pharmaceutical composition that contains rimegepant sulfate and is formulated as an "oral solid molded fast-dispersing dosage form" (Compl. ¶25). The complaint asserts the ANDA purports to contain data showing bioequivalence to NURTEC ODT® (Compl. ¶11).

IV. Analysis of Infringement Allegations

No probative visual evidence provided in complaint.

  • Claim Chart Summary: The complaint pleads infringement based on the submission of the ANDA under 35 U.S.C. § 271(e)(2)(A), alleging that the product described therein will infringe the ’724 Patent if commercially marketed (Compl. ¶21). The allegations for Claim 1 are summarized below.

'724 Patent Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
A pharmaceutical composition comprising a pharmaceutically acceptable carrier and a therapeutically effective amount of a CGRP receptor antagonist, or a pharmaceutically acceptable salt thereof Rubicon’s ANDA Product will contain a pharmaceutical composition comprising a therapeutically effective amount of rimegepant sulfate, which is a pharmaceutically acceptable salt of the CGRP receptor antagonist rimegepant. ¶25 col. 8:39-49
wherein the pharmaceutical composition is in a form of an oral solid molded fast-dispersing dosage form. The pharmaceutical composition of Rubicon’s ANDA Product will be in a form of an oral solid molded fast-dispersing dosage form. ¶25 col. 10:1-6
  • Identified Points of Contention: Given that the complaint is filed in response to a Paragraph IV certification of non-infringement, the central dispute will likely concern the scope and meaning of the claim terms relative to the technical details of the defendant's formulation as described in its confidential ANDA.
    • Scope Questions: A primary question will be whether Rubicon's proposed generic ODT falls within the scope of an "oral solid molded fast-dispersing dosage form" as that term is defined by the patent's specification and prosecution history.
    • Technical Questions: Does the manufacturing process for Rubicon's ANDA product involve the specific "molding" and "subliming solvent" (i.e., lyophilization) techniques described in the ’724 Patent (’724 Patent, col. 10:11-17), or does Rubicon employ a different technology for creating an orally disintegrating tablet that it will argue is outside the claimed invention?

V. Key Claim Terms for Construction

  • The Term: "oral solid molded fast-dispersing dosage form"
  • Context and Importance: This term is the central limitation defining the patented technology. Rubicon's non-infringement defense, as indicated by its Paragraph IV certification, will almost certainly hinge on arguing that its product, while being an ODT, does not meet the specific definition of a "molded" dosage form as contemplated by the patent. The construction of this term may be dispositive of the infringement analysis.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: A party arguing for a broader construction might point out that the claim language itself does not explicitly require a specific manufacturing process like "freeze-drying" or "lyophilization." It could argue that any process that results in a solid dosage form created in a mold that disperses quickly in the oral cavity meets the literal claim language.
    • Evidence for a Narrower Interpretation: A party arguing for a narrower construction may cite the specification, which states that for the claimed dosage form, the "network is obtained by subliming solvent from a composition in the solid state" and that this "is preferably carried out by freeze drying" (’724 Patent, col. 10:11-17). The specification also incorporates by reference a U.K. patent describing a specific freeze-drying process for such tablets (’724 Patent, col. 10:17-20). This evidence could be used to argue that the term "molded" is not merely descriptive of shape but is a term of art tied to this specific lyophilization-based manufacturing method.

VI. Other Allegations

  • Indirect Infringement: The complaint alleges that upon FDA approval, Rubicon will induce and contribute to infringement (Compl. ¶¶ 23, 28). The inducement claim is based on the allegation that Rubicon intends for its product to be used in an infringing manner and will actively encourage such use, presumably through its product labeling and marketing materials (Compl. ¶27). The contributory infringement claim alleges that Rubicon's product is especially made for infringing the patent and is not suitable for a substantial non-infringing use (Compl. ¶28).
  • Willful Infringement: The complaint alleges that Rubicon has acted with "full knowledge of the '724 patent" and without a reasonable basis for its non-infringement position, citing the Paragraph IV notice as evidence of knowledge (Compl. ¶26). Pfizer alleges that Rubicon "specifically intends infringement" and seeks a finding that the case is exceptional under 35 U.S.C. § 285, which would permit an award of attorneys' fees (Compl. ¶31).

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

  • A core issue will be one of claim construction: Can the term "oral solid molded fast-dispersing dosage form" be limited by the specification's detailed description of a freeze-drying (lyophilization) process, or will it be given a broader meaning that could encompass other methods of manufacturing molded, orally disintegrating tablets?
  • A key evidentiary question will be one of technical comparison: Do the specific formulation and manufacturing processes detailed in Rubicon's confidential ANDA fall within the scope of the key claim term as construed by the court? The resolution will depend on a fact-intensive analysis of Rubicon’s technology versus the teachings of the ’724 Patent.
  • A third question, not detailed in the complaint but inherent in any Paragraph IV litigation, will be the validity of the patent: What arguments and prior art will Rubicon present to support its assertion in its Paragraph IV letter that the claims of the ’724 Patent are invalid or unenforceable, and can Pfizer rebut those contentions?