DCT

1:19-cv-00752

Pfizer Inc v. Mylan Pharma Inc

Log In
Key Events
Complaint

I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 1:19-cv-00752, D. Del., 04/25/2019
  • Venue Allegations: Venue is asserted based on Plaintiff Pfizer Inc.'s incorporation in Delaware and Defendant Mylan's alleged continuous and systematic business contacts within the state, including the marketing and sale of other generic pharmaceutical products.
  • Core Dispute: Plaintiff alleges that Defendant’s submission of an Abbreviated New Drug Application (ANDA) to market generic versions of the cancer drug IBRANCE® (Palbociclib) constitutes an act of infringement of three patents related to the drug's composition of matter and method of use.
  • Technical Context: The technology concerns a chemical compound, Palbociclib, which functions as an inhibitor of cyclin-dependent kinases (CDK) 4 and 6, a mechanism used in the treatment of certain types of cancer.
  • Key Procedural History: The litigation was initiated under the Hatch-Waxman Act following a notice letter dated March 18, 2019, in which Mylan informed Pfizer of its ANDA filing. Mylan's filing included a Paragraph IV certification, asserting that Pfizer’s patents are invalid, unenforceable, or will not be infringed by Mylan's proposed generic product.

Case Timeline

Date Event
2002-01-22 Priority Date for ’612, ’489, and ’168 Patents
2005-08-30 U.S. Patent No. 6,936,612 Issued
2007-04-24 U.S. Patent No. 7,208,489 Issued
2008-11-25 U.S. Patent No. 7,456,168 Issued
2019-03-18 Mylan sends Notice Letter to Pfizer regarding ANDA filing
2019-04-25 Complaint Filed

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

U.S. Patent No. 6,936,612 - 2-(Pyridin-2-ylamino)-pyrido[2,3-d]pyrimidin-7-ones

The Invention Explained

  • Problem Addressed: The patent addresses the role of abnormally activated cyclin-dependent kinases (CDKs) in the development of human tumors and other cell proliferative disorders. The background notes the difficulty of identifying small molecule inhibitors that can selectively target specific CDK proteins. (’612 Patent, col. 1:13-2:28).
  • The Patented Solution: The invention provides a class of substituted 2-amino pyridine compounds that act as potent and selective inhibitors of CDK4. These compounds, as described in the specification, are designed to inhibit cell cycle progression and are therefore useful in treating diseases characterized by uncontrolled cell proliferation. (’612 Patent, col. 2:32-3:30; Abstract).
  • Technical Importance: The invention provides a chemical tool for treating proliferative diseases such as cancer and restenosis by selectively targeting the CDK4 and CDK6 kinase pathways, offering a more focused therapeutic approach than general cytotoxic agents. (’612 Patent, col. 3:36-46).

Key Claims at a Glance

  • Independent claim 1 is asserted in the complaint. (Compl. ¶29).
  • Claim 1:
    • A 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 also asserts dependent claim 2, which claims a pharmaceutical composition containing the compound of claim 1. (Compl. ¶25, ¶29).

U.S. Patent No. 7,208,489 - 2-(pyridin-2-ylamino)-pyrido [2,3-d]pyrimidin-7-ones

The Invention Explained

  • Problem Addressed: As a continuation of the application leading to the ’612 Patent, this patent addresses the same technical problem: the need for selective CDK inhibitors to treat cell proliferative diseases like cancer. (’489 Patent, col. 1:14-2:44).
  • The Patented Solution: The patent claims a genus of substituted 2-amino pyridine compounds, defined by a Markush structure (Formula I), which function as potent inhibitors of CDK4. This genus encompasses the specific compound claimed in the ’612 Patent. (’489 Patent, Abstract; col. 2:45-3:44).
  • Technical Importance: This patent broadens the proprietary scope around the core chemical structure, protecting a family of related compounds that are useful for treating cancer, restenosis, and inflammatory diseases due to their CDK4/6 selectivity. (’489 Patent, col. 3:45-55).

Key Claims at a Glance

  • Independent claim 1 is asserted in the complaint. (Compl. ¶68).
  • Claim 1:
    • A compound having the chemical structure of Formula I, which defines a pyrido[2,3-d]pyrimidin-7-one core.
    • The structure is defined by a set of variable substituents (R¹, R², R³, R⁴, X¹, X², X³) drawn from specified chemical groups (Markush groups).
  • The complaint also asserts dependent claims 2-7 and 9. (Compl. ¶68).

U.S. Patent No. 7,456,168 - 2-(pyridin-2-ylamino)-pyrido [2,3-d]pyrimidin-7-ones

  • Technology Synopsis: This patent claims methods of using the compounds disclosed in the parent ’612 and ’489 patents. The invention addresses the problem of treating breast cancer by providing a method that comprises administering a therapeutically effective amount of a compound from the claimed genus. (Compl. ¶103).
  • Asserted Claims: Claims 1-4. (Compl. ¶107).
  • Accused Features: The complaint alleges that the use of Mylan's ANDA Product, as directed by its proposed labeling, will infringe the claimed method of treating breast cancer. (Compl. ¶107, ¶111).

III. The Accused Instrumentality

Product Identification

Mylan's proposed generic Palbociclib capsules in 75 mg, 100 mg, and 125 mg dosage forms, referred to as "Mylan's ANDA Product." (Compl. ¶¶1-2).

Functionality and Market Context

The accused product is a pharmaceutical composition containing the active ingredient Palbociclib, the same compound as in Pfizer’s branded drug IBRANCE®. (Compl. ¶1). The product is intended for use in treating cancer, and the complaint alleges Mylan is seeking FDA approval to manufacture and sell this product as a generic alternative to IBRANCE® prior to the expiration of the patents-in-suit. (Compl. ¶1, ¶104).

No probative visual evidence provided in complaint.

IV. Analysis of Infringement Allegations

’612 Patent Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
A 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. Mylan's ANDA Product is alleged to be a pharmaceutical composition containing the identical chemical compound recited in claim 1. ¶29, ¶33 col. 43:60-44:23

Identified Points of Contention: The complaint alleges that in its notice letter, Mylan did not contest infringement of claims 1 and 2 of the ’612 Patent on any basis other than the patent’s alleged invalidity. (Compl. ¶30). This suggests that the primary dispute may concern patent validity rather than construction or application of the claim language to the accused product. A central question for the infringement analysis, therefore, is one of direct correspondence: does Mylan's ANDA product contain the exact chemical structure recited in claim 1?

’489 Patent Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
A compound of Formula I [a genus of pyrido[2,3-d]pyrimidin-7-ones defined by a Markush structure]. Mylan's ANDA Product, Palbociclib, is alleged to be a chemical species that falls within the genus of compounds claimed by Formula I. ¶68, ¶72 col. 2:45-3:44

Identified Points of Contention: Similar to the ’612 Patent, the complaint alleges that Mylan did not contest infringement of the asserted claims of the ’489 Patent on grounds other than invalidity. (Compl. ¶69). The infringement analysis raises a question of scope: does the specific chemical structure of Palbociclib meet all the structural limitations required for a compound to fall within the genus defined by Formula I in claim 1?

V. Key Claim Terms for Construction

The complaint does not provide sufficient detail for analysis of specific claim terms that may be in dispute. Claim 1 of the ’612 Patent recites a specific chemical compound by its IUPAC name. In ANDA litigation involving such a claim, where the accused product is a bioequivalent version of the brand-name drug, disputes over claim construction are less common than disputes over patent validity. The complaint's assertion that Mylan is not contesting infringement on any basis other than invalidity supports the possibility that claim construction will not be a central issue. (Compl. ¶30, ¶69).

VI. Other Allegations

  • Indirect Infringement: The complaint alleges active inducement on the basis that Mylan's proposed product labeling will instruct physicians and patients to use its generic product in a manner that infringes the asserted claims, and that Mylan has knowledge of the patents. (Compl. ¶35, ¶74, ¶112, ¶129). It further alleges contributory infringement, stating that Mylan's product is not a staple article of commerce and is especially made for an infringing use. (Compl. ¶36, ¶75, ¶130).
  • Willful Infringement: The complaint alleges that Mylan has acted with full knowledge of the patents-in-suit, stemming from its ANDA filing and Paragraph IV certification, and without a reasonable basis for believing it would not be liable. (Compl. ¶39, ¶78, ¶116).

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

Based on the complaint, the infringement dispute appears to center on the following key questions:

  • A core issue will be one of chemical identity: will chemical analysis confirm that Mylan’s ANDA product contains the exact compound recited in Claim 1 of the ’612 Patent and is a species encompassed by the genus claim of the ’489 Patent? The complaint’s allegation that Mylan does not contest infringement on other grounds suggests this may be stipulated, shifting the focus to validity.
  • A key question for the method-of-use claims in the ’168 Patent will be one of induced infringement: does Mylan’s proposed product label, by its instructions for use, demonstrate a specific intent to encourage physicians and patients to administer the generic drug in a manner that directly infringes the claimed method of treating breast cancer?