DCT

1:19-cv-00743

Pfizer Inc v. Aizant Drug Research Solutions Pvt Ltd

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Key Events
Amended Complaint

I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 1:19-cv-00743, D. Del., 06/03/2020
  • Venue Allegations: Plaintiff alleges venue is proper in the District of Delaware because Defendant Alembic Pharmaceuticals, Inc. is a Delaware corporation and Defendant Alembic Pharmaceuticals, Ltd. is subject to personal jurisdiction in the district. The complaint notes that in a related action, Defendants did not contest personal jurisdiction or venue in the district for the limited purposes of that action.
  • Core Dispute: Plaintiff alleges that Defendants' submission of an Abbreviated New Drug Application ("ANDA") to the U.S. Food and Drug Administration, seeking approval to market a generic version of the breast cancer drug IBRANCE® (Palbociclib), constitutes an act of infringement of three U.S. patents covering the palbociclib compound, pharmaceutical compositions, and methods of use.
  • Technical Context: The technology concerns Palbociclib, a chemical compound that functions as a selective inhibitor of cyclin-dependent kinases 4 and 6 (CDK4/6), a class of enzymes central to regulating cell cycle progression, making it a therapeutic agent for certain types of cancer.
  • Key Procedural History: The litigation was initiated under the Hatch-Waxman Act following Defendants' notification to Plaintiff of the submission of ANDA No. 213128. The notification included Paragraph IV certifications asserting that the patents-in-suit are invalid, unenforceable, and/or will not be infringed by the proposed generic product.

Case Timeline

Date Event
2002-01-22 Priority Date for ’612, ’739, and ’168 Patents
2005-08-30 U.S. Patent No. 6,936,612 Issued
2008-11-25 U.S. Patent No. 7,456,168 Issued
2019-03-19 Alembic's First Notice Letter to Pfizer
2019-11-26 U.S. Reissue Patent No. RE47,739 Issued
2020-05-15 Alembic's Supplemental Notice Letter to Pfizer
2020-06-03 First Amended 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”

  • Issued: August 30, 2005 (the “’612 Patent”)

The Invention Explained

  • Problem Addressed: The patent describes the role of cyclin-dependent kinases (CDKs) in regulating cell division and proliferation, noting that increased or abnormal activity of these kinases can lead to the development of human tumors and other cell proliferative diseases (’612 Patent, col. 1:13-30).
  • The Patented Solution: The invention provides a class of chemical compounds, specifically substituted 2-amino pyridines, that are potent and selective inhibitors of CDK4 and are therefore useful for treating disorders arising from abnormal cell proliferation, such as cancer (’612 Patent, col. 1:8-12, col. 2:30-34, Abstract). The specification describes these compounds as having utility as anti-cancer, anti-inflammatory, and anti-infective agents (’612 Patent, col. 3:35-39).
  • Technical Importance: The development of small molecule inhibitors selective for specific CDKs was a key objective in oncology research, aimed at creating targeted therapies that could arrest tumor growth with potentially fewer side effects than traditional chemotherapy (’612 Patent, col. 1:44-col. 2:28).

Key Claims at a Glance

  • The complaint asserts independent claim 1 and dependent claim 2 (Compl. ¶¶ 28-29, 33).
  • Claim 1 (Independent):
    • 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.
  • Claim 2 (Dependent):
    • A pharmaceutical composition comprising a therapeutically effective amount of the compound of claim 1 and a pharmaceutical carrier.

U.S. Reissue Patent No. RE47,739 - “2-(pyridin-2-ylamino)-pyrido [2,3-d]pyrimidin-7-ones”

  • Issued: November 26, 2019 (the “’739 Patent”)

The Invention Explained

  • Problem Addressed: As a reissue of the ’612 Patent, the ’739 Patent addresses the same technical problem of abnormal cell proliferation driven by CDK activity (’612 Patent, col. 1:13-30).
  • The Patented Solution: The patent claims a genus of CDK4-inhibiting compounds, providing a structural formula that encompasses a range of related 2-amino pyridine derivatives useful for treating diseases such as cancer (’612 Patent, col. 2:30-34). Reissue patents are typically sought to correct errors in the original patent, often to broaden or narrow claim scope, which may be a relevant issue in this litigation.
  • Technical Importance: As described for the ’612 Patent, the technical approach provides selective small molecule inhibitors for targeted cancer therapy.

Key Claims at a Glance

  • The complaint asserts claims 2, 6, 7, and 9-12 (Compl. ¶¶ 69, 72).
  • The complaint states that claim 2 recites a compound of a specific formula but does not provide the text of the claim or the formula itself, precluding a detailed breakdown of its elements (Compl. ¶ 68).

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

  • Issued: November 25, 2008 (the “’168 Patent”)
  • Technology Synopsis: The patent claims methods of using the CDK-inhibiting compounds described in the ’612 patent family for the specific purpose of treating breast cancer in a mammal. This type of patent protects a specific application of a known compound.
  • Asserted Claims: Claims 1-4 are asserted, with claim 1 being an independent method-of-treatment claim (Compl. ¶¶ 107, 111).
  • Accused Features: The use of Alembic’s ANDA Product is accused of infringing, particularly as directed by its proposed product labeling for the treatment of breast cancer (Compl. ¶¶ 111, 115).

III. The Accused Instrumentality

Product Identification

Alembic’s ANDA Product, which is a proposed generic version of IBRANCE® (Palbociclib) capsules in 75 mg, 100 mg, and 125 mg dosages (Compl. ¶ 1).

Functionality and Market Context

The complaint frames the infringing act as the submission of ANDA No. 213128 to the FDA under the Hatch-Waxman Act (Compl. ¶¶ 1, 35). This statutory act seeks approval to manufacture, use, and sell a drug product that is the bioequivalent of Pfizer's IBRANCE® before the expiration of the patents-in-suit (Compl. ¶ 1). The complaint alleges that Pfizer’s IBRANCE® product is covered by the asserted patents and listed in the FDA’s Orange Book, thereby putting generic manufacturers on notice (Compl. ¶¶ 30, 69, 108).

IV. Analysis of Infringement Allegations

No probative visual evidence provided in complaint.

’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. Alembic's ANDA Product contains palbociclib, the compound recited in claim 1, as its active pharmaceutical ingredient. ¶33 col. 45:3-21
  • Identified Points of Contention: The complaint alleges that in its notice letter, Alembic did not contest infringement of claims 1 and 2 of the ’612 Patent on any basis other than the alleged invalidity of those claims (Compl. ¶ 34). In the context of ANDA litigation, infringement is often conceded if the patent is valid, as the generic product must be the same as the branded product. A potential point of contention, however, may arise from Alembic’s formal certification of non-infringement (Compl. ¶ 32), the basis for which is not detailed in the complaint.

’739 Patent Infringement Allegations

The complaint does not provide the text of the asserted claims of the ’739 patent, precluding the creation of a detailed claim chart summary. The complaint’s infringement theory is that Alembic’s ANDA Product and its intended use are covered by at least claims 2, 6, 7, and 9–12 of the patent (Compl. ¶ 72). The complaint alleges that Alembic’s supplemental notice letter did not contest infringement on any basis other than alleged invalidity (Compl. ¶ 73).

  • Identified Points of Contention: As with the ’612 Patent, the central dispute will likely be validity, not infringement. A key question for the infringement analysis is whether the asserted claims of the reissue patent have a scope that is materially different from the original ’612 Patent and whether any such difference creates a non-infringement argument for Alembic's specific ANDA product or its manufacturing process.

V. Key Claim Terms for Construction

The complaint does not provide sufficient detail for analysis of key claim terms. The asserted independent claim of the ’612 Patent recites a specific chemical compound by its IUPAC name, which is a format that typically does not give rise to significant claim construction disputes.

VI. Other Allegations

  • Indirect Infringement: The complaint alleges both induced and contributory infringement. The inducement allegation is based on the assertion that Alembic’s proposed product labeling will actively instruct physicians and patients to administer the generic product in a manner that directly infringes the method claims of the ’168 Patent (Compl. ¶¶ 39, 115). The contributory infringement allegation is based on the assertion that Alembic's product is especially made for an infringing use and is not a staple article of commerce suitable for substantial non-infringing use (Compl. ¶¶ 40, 117).
  • Willful Infringement: Willfulness is alleged based on Defendants having "acted with full knowledge of the" patents-in-suit and "without a reasonable basis for believing that it would not be liable for infringement" (Compl. ¶¶ 43, 82, 100, 120). This knowledge is predicated on the patents' listing in the FDA's Orange Book and the formal notice letters sent by Alembic as part of the ANDA process.

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

  • A core issue will be one of patent validity: As the complaint suggests infringement itself is not the primary point of contention, the case will likely turn on whether Defendants can prove by clear and convincing evidence that the asserted patent claims are invalid, for reasons such as anticipation, obviousness, or lack of enablement, based on the prior art and the state of the field at the time of the invention.
  • A key procedural question will be one of statutory infringement and remedy: The central act of infringement is the ANDA filing itself under 35 U.S.C. § 271(e)(2). The key question for the court will be whether this statutory act of infringement is proven and, if so, what the proper remedy should be, which under the Hatch-Waxman Act typically involves an order setting the effective date of the ANDA approval to be no earlier than the expiration of the infringed patents.
  • A third central question will be one of culpability: Can Pfizer establish that Alembic's conduct—proceeding with its ANDA submission despite knowledge of the patents—was sufficiently egregious to meet the high bar for willful infringement, potentially exposing Alembic to enhanced damages if its product launches.