Pfizer Inc v. DR Reddy's Laboratories Inc

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: Pfizer Inc. (Delaware), Warner-Lambert Company LLC (Delaware), PF Prism CV. (Netherlands), Pfizer Manufacturing Holdings LLC (Delaware), and Pfizer PFE Ireland Pharmaceuticals Holding 1 B.V. (Netherlands)
  • Defendant: Dr. Reddy's Laboratories, Inc. (New Jersey) and Dr. Reddy's Laboratories, Ltd. (India)
  • Plaintiff’s Counsel: Gibbons P.C.; Williams & Connolly LLP
• Case Identification: 1:19-cv-11742, D.N.J., 04/29/2019
• Venue Allegations: Venue is alleged in the District of New Jersey based on Defendant Dr. Reddy's Laboratories, Inc. being a corporation organized under New Jersey law with a principal place of business in the state, and upon allegations that it will market and sell the accused product within the district.
• Core Dispute: Plaintiff alleges that Defendant’s Abbreviated New Drug Application (ANDA) to market a generic version of the cancer drug IBRANCE® (Palbociclib) constitutes an act of infringement of three U.S. patents covering the chemical compound, pharmaceutical compositions, and methods of use.
• Technical Context: The technology at issue involves Palbociclib, a small molecule inhibitor of cyclin-dependent kinases 4 and 6 (CDK4/6) used in the treatment of certain types of breast cancer.
• Key Procedural History: This action was initiated under the Hatch-Waxman Act following a notice letter from Defendant, dated March 19, 2019, informing Plaintiff of its ANDA filing containing a Paragraph IV certification that the patents-in-suit are invalid, unenforceable, or will not be infringed by the proposed generic product.

Case Timeline

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"

• Patent Identification: U.S. Patent No. 6,936,612, titled "2-(PYRIDIN-2-YLAMINO)-PYRIDO[2,3-D] PYRIMIDIN-7-ONES," issued August 30, 2005.

The Invention Explained

• Problem Addressed: The patent’s background section describes that cyclin-dependent kinases (Cdks) are essential enzymes for regulating cell division and proliferation, and that increased or abnormal Cdk activity is commonly associated with the development of human tumors (ʼ612 Patent, col. 1:12-35). This created a need for small-molecule Cdk inhibitors to treat such cell proliferative diseases.
• The Patented Solution: The invention provides substituted 2-aminopyridine compounds that are potent inhibitors of Cdk4, a specific cyclin-dependent kinase (ʼ612 Patent, Abstract; col. 2:30-31). The patent discloses a class of compounds having a pyrido[2,3-d]pyrimidin-7-one core structure designed to inhibit Cdk4 and thereby treat disorders like cancer and restenosis (ʼ612 Patent, col. 1:8-18).
• Technical Importance: The development of selective Cdk inhibitors provided a targeted therapeutic approach for cancers driven by aberrant cell cycle progression, moving beyond less specific cytotoxic chemotherapies (ʼ612 Patent, col. 2:6-16).

Key Claims at a Glance

• The complaint asserts independent claim 1 and dependent claim 2 (Compl. ¶¶ 22-23, 27).
• Essential elements of independent 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 notes that Claim 2 recites a pharmaceutical composition comprising the compound of claim 1 (Compl. ¶ 23).

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

• Patent Identification: U.S. Patent No. 7,208,489, titled "2-(pyridin-2-ylamino)-pyrido[2,3-d]pyrimidin-7-ones," issued April 24, 2007.

The Invention Explained

• Problem Addressed: The patent addresses the same technical problem as the parent ’612 Patent: the need for potent inhibitors of cyclin-dependent kinases to treat cell proliferative diseases such as cancer (ʼ489 Patent, col. 2:1-44).
• The Patented Solution: This invention claims a genus of substituted 2-aminopyridine compounds, defined by a general Markush structure (Formula I), that function as potent inhibitors of Cdk4 (ʼ489 Patent, Abstract; col. 2:45-51). Palbociclib, the specific compound claimed in the ’612 Patent, is an embodiment of this broader genus.
• Technical Importance: By claiming a genus of related chemical structures, the patent sought to protect a class of compounds with a shared therapeutic mechanism, providing broader protection for the core chemical scaffold and its variations (ʼ489 Patent, col. 3:31-46).

Key Claims at a Glance

• The complaint asserts claims 1-7 and 9 (Compl. ¶¶ 63, 66). Claim 1 is the sole independent claim asserted.
• Essential elements of independent claim 1:
  • A compound of Formula I, which is a 2-(pyridin-2-ylamino)-pyrido[2,3-d]pyrimidin-7-one scaffold
  • The scaffold is substituted with various chemical groups (R¹, R², R³, R⁴, X¹, X², X³) selected from specified Markush groups.
• The complaint does not explicitly state an intent to assert other dependent claims but alleges infringement of claims 1-7 and 9 generally (Compl. ¶ 66).

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

• Patent Identification (Multi-Patent Capsule): U.S. Patent No. 7,456,168, titled "2-(pyridin-2-ylamino)-pyrido[2,3-d]pyrimidin-7-ones," issued November 25, 2008.
• Technology Synopsis: The ’168 patent addresses the use of the previously disclosed Cdk4-inhibiting compounds for a specific therapeutic purpose. It claims a method for treating breast cancer in a mammal by administering a compound of the formula recited in its claim 1, which encompasses Palbociclib.
• Asserted Claims: The complaint asserts claims 1-4 (Compl. ¶ 105). Claim 1 is the asserted independent claim.
• Accused Features: The accused feature is the future use of Defendant's ANDA product for treating breast cancer, which the complaint alleges will be induced by the product's proposed labeling (Compl. ¶¶ 101, 110).

III. The Accused Instrumentality

No probative visual evidence provided in complaint.

Product Identification

Defendant’s proposed generic Palbociclib capsules in 75 mg, 100 mg, and 125 mg dosages, for which Defendant submitted ANDA No. 213091 to the FDA ("DRL's ANDA Product") (Compl. ¶ 2).

Functionality and Market Context

DRL's ANDA Product contains Palbociclib as its active pharmaceutical ingredient, the same active ingredient in Plaintiff's branded drug IBRANCE® (Compl. ¶ 1). The complaint alleges that this product is a generic version of IBRANCE® and that Defendant seeks FDA approval to commercially manufacture and sell it in the United States prior to the expiration of the patents-in-suit (Compl. ¶¶ 1-2). IBRANCE® is listed in the FDA's Orange Book in connection with the patents-in-suit as a treatment for breast cancer (Compl. ¶¶ 24, 63, 102).

IV. Analysis of Infringement Allegations

U.S. Patent No. 6,936,612 Infringement Allegations

U.S. Patent No. 7,208,489 Infringement Allegations

Identified Points of Contention

• Technical Questions: The complaint alleges that Defendant, in its Paragraph IV notice letter, did not contest infringement of the asserted claims of the patents-in-suit on any basis other than alleged invalidity (Compl. ¶¶ 28, 67, 106). This suggests that the technical operation or chemical structure of the accused product is not the primary point of contention. The dispute, as framed by the complaint, centers on Defendant’s affirmative defense of invalidity.
• Scope Questions: For the ’489 Patent, a threshold question for infringement is whether the specific compound Palbociclib is encompassed by the scope of the Markush groups defined in claim 1. The complaint alleges that it is and that this point is not contested by Defendant (Compl. ¶¶ 66-67).

V. Key Claim Terms for Construction

The complaint does not provide sufficient detail for analysis of specific terms for construction. In this Hatch-Waxman action, the complaint alleges that Defendant does not contest infringement of the asserted claims but instead relies on an invalidity defense (Compl. ¶¶ 28, 67, 106). This procedural posture suggests that claim construction disputes, if they arise, may be secondary to validity arguments. However, practitioners may focus on the scope of the various Markush group limitations in claim 1 of the ’489 patent (e.g., "alkyl," "heteroaryl") if Defendant's invalidity case rests on grounds of written description or enablement for the full scope of the claimed genus.

VI. Other Allegations

• Indirect Infringement: The complaint alleges active inducement of infringement on the basis that Defendant’s proposed product labeling will instruct physicians and patients to use the generic product in a manner that infringes the asserted method claims of the ’168 patent (Compl. ¶¶ 33, 72, 110-111). It also alleges contributory infringement, stating the accused product is especially made for an infringing use and is not a staple article of commerce suitable for substantial non-infringing use (Compl. ¶¶ 34, 73, 112).
• Willful Infringement: Willfulness is alleged based on Defendant’s knowledge of the patents-in-suit, as evidenced by its ANDA filing and Paragraph IV certification, and its alleged lack of a reasonable basis to believe it would not be liable for infringement (Compl. ¶¶ 37, 76, 115).

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

The complaint frames this dispute as a quintessential Hatch-Waxman action where the central conflict is not over whether the proposed generic product meets the claim limitations, but whether the patent claims are valid in the first place.

• A core issue will be one of validity: As infringement is allegedly uncontested, the case will likely focus on whether Defendant can prove by clear and convincing evidence that the asserted claims are invalid on grounds such as anticipation, obviousness, or lack of written description or enablement.
• A key question for the ’489 patent will be one of scope and enablement: Can the broad Markush genus claimed in the ’489 patent withstand a validity challenge under 35 U.S.C. § 112? The court may need to determine if the specification provides adequate written description and enabling disclosure for the full scope of the claimed chemical genus, including the particular species that is Palbociclib.