DCT

1:24-cv-01122

Pfizer Inc v. Breckenridge Pharmaceutical Inc

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I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 1:24-cv-01122, D. Del., 10/09/2024
  • Venue Allegations: Venue is based on Defendant’s consent to venue for the purposes of this litigation.
  • Core Dispute: Plaintiff alleges that Defendant’s submission of an Abbreviated New Drug Application (ANDA) for a generic version of the drug Xeljanz® constitutes an act of infringement of a patent covering the active pharmaceutical ingredient, tofacitinib.
  • Technical Context: The technology concerns a specific pyrrolo[2,3-d]pyrimidine compound, tofacitinib, which functions as a Janus kinase (JAK) inhibitor for treating various autoimmune diseases.
  • Key Procedural History: The complaint notes that Pfizer previously sued Breckenridge over its ANDA for a 5 mg dosage strength of Xeljanz®, a case that was voluntarily dismissed pursuant to a settlement agreement. The current action concerns an amendment to the same ANDA for a 10 mg dosage strength. The patent-in-suit is a reissue of U.S. Patent No. 6,627,754 and its expiration date was extended to December 8, 2025.

Case Timeline

Date Event
1999-12-10 Earliest Priority Date for RE41,783 Patent
2003-09-30 Issue Date of Original U.S. Patent No. 6,627,754
2010-09-28 Issue Date of U.S. Reissue Patent No. RE41,783
2016-12-14 USPTO extends RE41,783 patent expiration date
2024-08-26 Breckenridge sends Notice Letter regarding ANDA amendment
2024-10-09 Complaint Filing Date
2025-12-08 Expiration Date for RE41,783 Patent

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

U.S. Reissue Patent No. RE41,783 - "Pyrrolo[2,3-d]pyrimidine Compounds," issued September 28, 2010

The Invention Explained

  • Problem Addressed: The patent addresses the need for compounds that can inhibit protein kinases, specifically the Janus Kinase 3 (JAK3) enzyme, to serve as effective immunosuppressive agents (RE’783 Patent, col. 1:12-23). Such agents are described as useful for treating a range of conditions where immunosuppression is desirable, including organ transplant rejection and autoimmune diseases like rheumatoid arthritis and psoriasis (RE’783 Patent, col. 1:15-23). The patent notes that JAK3 expression is limited to hematopoietic cells and is essential for signaling through various interleukin receptors, making it a targeted pathway for modulating immune activity (RE’783 Patent, col. 1:26-42).
  • The Patented Solution: The invention provides a class of pyrrolo[2,3-d]pyrimidine compounds, and their pharmaceutically acceptable salts, which are claimed to inhibit JAK3 (RE’783 Patent, Abstract). The patent discloses specific chemical structures, including the compound identified in asserted Claim 4, which are designed to function as these inhibitors (RE’783 Patent, col. 24:25-31).
  • Technical Importance: By targeting the JAK3 pathway, which plays a critical role in B and T lymphocyte maturation and function, the invention offered a novel mechanism for modulating immune activity to treat T-cell proliferative disorders (RE’783 Patent, col. 1:36-42).

Key Claims at a Glance

  • The complaint asserts infringement of "at least claim 4" (Compl. ¶35). Claim 4 is dependent on Claim 3, which is dependent on Claim 1.
  • Independent Claim 1: Defines a broad genus of compounds with a core pyrrolo[2,3-d]pyrimidine structure and various substituent groups (R¹, R², R³), including a piperidinyl group (R⁵).
  • Asserted Claim 4: Claims a specific compound from within that genus:
    • 3-{4-Methyl-3-[methyl-(7H-pyrrolo[2,3-d]pyrimidin-4-yl)-amino]-piperidin-1-yl}-3-oxo-propionitrile, or a pharmaceutically acceptable salt thereof.

III. The Accused Instrumentality

Product Identification

  • The accused instrumentality is "Breckenridge Generic 10 mg Tofacitinib Tablets," a proposed generic drug product for which Breckenridge has sought FDA approval via an amendment to ANDA No. 209633 (Compl. ¶¶1-2, 27).

Functionality and Market Context

  • The complaint alleges that the proposed Breckenridge product is a generic copy of Pfizer's 10 mg Xeljanz® tablets (Compl. ¶2).
  • The product is described in Breckenridge's notice letter as "tofacitinib citrate oral tablets," containing the equivalent of 10 mg of tofacitinib base (Compl. ¶28). Tofacitinib is an inhibitor of Janus kinases (JAKs) indicated for the treatment of autoimmune conditions such as rheumatoid arthritis and ulcerative colitis (Compl. ¶17).
  • The alleged act of infringement is the filing of the ANDA seeking approval to market this generic product prior to the expiration of the RE’783 patent, which is listed in the FDA's Orange Book for Xeljanz® (Compl. ¶¶2, 19, 35).

IV. Analysis of Infringement Allegations

The complaint alleges that Breckenridge’s filing of its ANDA constitutes an act of infringement under 35 U.S.C. § 271(e)(2)(A), as the product that will be sold upon approval would directly infringe at least Claim 4 of the RE’783 patent (Compl. ¶¶35, 37). No probative visual evidence provided in complaint.

RE41,783 Infringement Allegations

Claim Element (from Claim 4) Alleged Infringing Functionality Complaint Citation Patent Citation
3-{4-Methyl-3-[methyl-(7H-pyrrolo[2,3-d]pyrimidin-4-yl)-amino]-piperidin-1-yl}-3-oxo-propionitrile, or a pharmaceutically acceptable salt thereof The complaint alleges that Breckenridge's proposed generic product contains tofacitinib citrate, which is the citrate salt of the compound recited in Claim 4. ¶¶15, 16, 28 col. 24:25-31
  • Identified Points of Contention:
    • Factual Question: The central infringement question is one of chemical identity: does the active pharmaceutical ingredient in Breckenridge's proposed generic product, as specified in its ANDA, fall within the structural definition of the compound claimed in Claim 4 of the RE’783 patent?
    • Scope Questions: While the complaint does not detail Breckenridge’s non-infringement theories, disputes in such cases can sometimes turn on whether the specific salt form in the generic product (citrate) is a "pharmaceutically acceptable salt thereof" as required by the claim. Another question is whether the ANDA product contains a different polymorph or chemical form that Breckenridge might argue is outside the scope of the asserted claim.

V. Key Claim Terms for Construction

The complaint does not provide sufficient detail for analysis of specific claim terms that may be in dispute. As Claim 4 recites a specific chemical compound, claim construction disputes are less common than in other technologies, but may arise regarding the precise structural or stereochemical features of the molecule if not explicitly defined.

VI. Other Allegations

  • Indirect Infringement: The prayer for relief seeks an injunction against inducing or contributing to infringement (Compl. p. 8, ¶C). However, the body of the complaint focuses on direct infringement under 35 U.S.C. § 271(a) and the statutory act of infringement under § 271(e)(2), without pleading specific facts to support a separate theory of induced or contributory infringement.
  • Willful Infringement: The complaint does not use the term "willful infringement." It alleges that Breckenridge had knowledge of the RE’783 patent when it submitted its ANDA amendment, citing the notice letter sent to Pfizer (Compl. ¶¶27, 36). The prayer for relief requests a judgment that this is an "exceptional case" under 35 U.S.C. § 285, which could entitle Pfizer to attorneys' fees (Compl. p. 9, ¶D).

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

This litigation presents a classic Hatch-Waxman dispute centered on a compound patent. Based on the complaint, the case will likely turn on the following core questions:

  • A primary question will be one of validity: Although not detailed in the complaint, Breckenridge’s ANDA filing included a Paragraph IV certification alleging that the RE’783 patent is "invalid, unenforceable, and/or will not be infringed" (Compl. ¶30). The resolution of the case will therefore heavily depend on whether Breckenridge can prove by clear and convincing evidence that Claim 4 is invalid on grounds such as obviousness or lack of written description.
  • The secondary issue is one of infringement scope: Assuming the patent is valid, does the specific tofacitinib citrate formulation described in Breckenridge's ANDA fall within the literal scope of Claim 4, which claims the base compound "or a pharmaceutically acceptable salt thereof"? The answer will likely depend on a straightforward comparison of the chemical structure in the ANDA with the claimed structure.