DCT

1:25-cv-00765

Pfizer Inc v. Apotex Inc

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I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 1:25-cv-00765, D. Del., 06/20/2025
  • Venue Allegations: Venue is alleged to be proper for Apotex Corp. as a Delaware corporation and for Apotex Inc. on the basis that it is subject to personal jurisdiction in the district.
  • Core Dispute: Plaintiff alleges that Defendant’s submission of an Abbreviated New Drug Application (ANDA) for generic versions of the breast cancer drug IBRANCE® (Palbociclib) constitutes an act of infringement of a patent covering the palbociclib compound.
  • Technical Context: The technology relates to small molecule kinase inhibitors, a class of compounds used in targeted cancer therapy to disrupt cell cycle progression in tumor cells.
  • Key Procedural History: The litigation was initiated under the Hatch-Waxman Act following a notice letter from Apotex informing Pfizer of its ANDA filing. The complaint states that Apotex's filing included a Paragraph IV certification asserting that the patent-in-suit is invalid, unenforceable, and/or will not be infringed, and further alleges that Apotex did not contest infringement on any basis other than the patent's alleged invalidity.

Case Timeline

Date Event
2002-01-22 ’739 Patent Priority Date
2019-11-26 ’739 Patent Issue Date
2025-05-09 Apotex Notice Letter Date
2025-06-20 Complaint Filing Date

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

U.S. Reissue Patent No. RE47,739 - 2-(PYRIDIN-2-YLAMINO)-PYRIDO[2,3-D] PYRIMIDIN-7-ONES

  • Issued: November 26, 2019

The Invention Explained

  • Problem Addressed: The patent describes the central role of cyclin-dependent kinases (Cdks) in regulating cell division and notes that abnormal Cdk activity is commonly associated with human tumors (’739 Patent, col. 4:36-54). The background section highlights the technical challenge of developing compounds that selectively inhibit specific Cdk proteins, such as Cdk4, without inhibiting other essential enzymes, which could cause undesirable side effects (’739 Patent, col. 4:30-44).
  • The Patented Solution: The invention discloses a class of substituted 2-aminopyridine compounds, specifically pyrido[2,3-d]pyrimidin-7-ones, that are described as potent and selective inhibitors of Cdk4 (’739 Patent, Abstract; col. 3:41-47). By inhibiting Cdk4, these compounds are intended to block the cell cycle progression of abnormally proliferating cells, thereby treating disorders such as cancer (’739 Patent, col. 4:21-26).
  • Technical Importance: The development of selective Cdk4/6 inhibitors provided a targeted therapeutic strategy for hormone receptor-positive (HR+) breast cancer, a major subtype of the disease (Compl. ¶22).

Key Claims at a Glance

  • The complaint asserts claims 2, 6, 7, and 9–12 (Compl. ¶31). Claim 2, which recites a specific compound, is the focal point of the infringement allegations (Compl. ¶30, 49).
  • Essential Elements of Claim 2: This claim recites the specific chemical compound known as palbociclib:
    • 6-acetyl-8-cyclopentyl-5-methyl-2-(5-piperazin-1-yl-pyridin-2-ylamino)-8H-pyrido[2,3-d]pyrimidin-7-one

III. The Accused Instrumentality

Product Identification

Apotex’s ANDA Products, identified as generic versions of IBRANCE® (Palbociclib) tablets in 75 mg, 100 mg, and 125 mg dosages (Compl. ¶1).

Functionality and Market Context

  • The accused products are alleged to contain palbociclib as the active pharmaceutical ingredient (Compl. ¶1, 22).
  • Functionally, the products are intended to be therapeutic equivalents to IBRANCE®, used for the treatment of HR-positive, HER2-negative advanced or metastatic breast cancer (Compl. ¶22, 23). The complaint asserts they are generic versions of Pfizer's brand-name drug, which implies they are intended to be bioequivalent and have the same mechanism of action (Compl. ¶23).

No probative visual evidence provided in complaint.

IV. Analysis of Infringement Allegations

The complaint’s infringement theory is based on 35 U.S.C. § 271(e)(2)(A), where the submission of an ANDA to obtain approval for a generic drug before patent expiration is a statutory act of infringement (Compl. ¶36). The core allegation is that Apotex's proposed generic product, if marketed, would contain the chemical compound claimed in the ’739 Patent.

’739 Patent Infringement Allegations

Claim Element (from Independent Claim 1, as specified in Claim 2) Alleged Infringing Functionality Complaint Citation Patent Citation
The compound... which is 6-acetyl-8-cyclopentyl-5-methyl-2-(5-piperazin-1-yl-pyridin-2-ylamino)-8H-pyrido[2,3-d]pyrimidin-7-one The complaint alleges that Apotex's ANDA Products contain palbociclib, which is the chemical compound recited in Claim 2, as the active pharmaceutical ingredient. ¶¶ 23, 30, 34 col. 85:22-26

Identified Points of Contention

  • Scope Questions: The complaint suggests that infringement of the compound claims may not be a primary point of dispute. It alleges that in its notice letter, "Apotex did not contest the infringement of claims 2, 6, 7 and 9–12 of the '739 patent on any basis other than the alleged invalidity of those claims" (Compl. ¶35, 53). This frames the central conflict as one of patent validity rather than claim scope or non-infringement.
  • Technical Questions: The primary technical question for the infringement analysis will be the chemical identity of the active ingredient in Apotex's ANDA product. Given that the product is intended as a generic version of IBRANCE®, the complaint proceeds on the basis that the active ingredient is the claimed palbociclib compound (Compl. ¶23).

V. Key Claim Terms for Construction

The complaint does not provide sufficient detail for analysis of specific claim terms that may be subject to construction. As the asserted claims recite a specific chemical structure by its IUPAC name, disputes are more likely to concern issues of patent validity (e.g., obviousness, written description) rather than the definition of claim terms.

VI. Other Allegations

  • Indirect Infringement: The complaint alleges active inducement on the basis that Apotex's proposed product labeling will direct medical providers and patients to use the generic product for the patented indication of treating breast cancer, thereby encouraging infringing acts (Compl. ¶39, 40, 57-58). Contributory infringement is alleged on the grounds that the accused products are especially made for an infringing use and are not staple articles suitable for substantial non-infringing use (Compl. ¶41, 59).
  • Willful Infringement: The complaint alleges that Apotex has acted with "full knowledge of the '739 patent" and lacks a reasonable basis to believe it would not be liable for infringement (Compl. ¶44, 62). This allegation is predicated on Apotex's pre-suit knowledge, evidenced by its submission of a Paragraph IV certification against a patent listed in the FDA's Orange Book (Compl. ¶31, 33).

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

Based on the complaint, the litigation appears poised to center on the validity of the ’739 Patent rather than on contested issues of infringement. The key questions for the case will likely be:

  • A central issue will be one of patent validity: can Apotex establish by clear and convincing evidence that the asserted claims covering the palbociclib compound are invalid, potentially on grounds of obviousness in light of prior art kinase inhibitors or for failure to meet other statutory requirements?
  • A secondary evidentiary question will be one of infringement confirmation: while the complaint alleges infringement is not contested, the case will require formal confirmation through discovery that the active pharmaceutical ingredient specified in Apotex's ANDA is, in fact, the palbociclib compound as claimed in the ’739 Patent.
  • A further question will be one of objective recklessness: if Apotex’s invalidity challenges fail, did its pre-suit decision to file an ANDA with a Paragraph IV certification against the Orange Book-listed ’739 Patent rise to the level of willful infringement?