DCT
2:19-cv-01846
Pfizer Inc v. Qilu Pharma Inc
I. Executive Summary and Procedural Information
- Parties & Counsel:
- Plaintiff: Pfizer Inc. et al. (Delaware & Netherlands)
- Defendant: Qilu Pharma, Inc. and Qilu Pharmaceutical Co., Ltd. (Pennsylvania & People's Republic of China)
- Plaintiff’s Counsel: GIBBONS P.C.; Williams & Connolly LLP
- Case Identification: 2:19-cv-01846, E.D. Pa., 04/29/2019
- Venue Allegations: Venue is based on Defendant Qilu Pharma, Inc. having its principal place of business in Pennsylvania, and on both defendants allegedly transacting business and intending to market the accused product within the district.
- Core Dispute: Plaintiff alleges that Defendant’s submission of an Abbreviated New Drug Application (ANDA) to market a generic version of the cancer drug IBRANCE® (Palbociclib) constitutes an act of infringement of three patents covering the compound, a genus of related compounds, and its method of use for treating breast cancer.
- Technical Context: The technology relates to small-molecule kinase inhibitors, specifically compounds that inhibit cyclin-dependent kinases (CDKs), which are critical for regulating cell division and are a significant target in oncology research.
- Key Procedural History: This patent infringement action was initiated under the Hatch-Waxman Act following Defendant's notification to Plaintiff on March 20, 2019, of its ANDA submission seeking FDA approval. The notification included a Paragraph IV certification asserting that the patents-in-suit are invalid, unenforceable, and/or will not be infringed.
Case Timeline
| Date | Event |
|---|---|
| 2002-01-22 | Earliest 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 |
| 2019-03-20 | Defendant Notifies Plaintiff of ANDA Filing |
| 2019-04-29 | 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 need for potent and selective inhibitors of cyclin-dependent kinase 4 (Cdk4) for the treatment of cell proliferative diseases such as cancer (Compl. ¶ 1; ’612 Patent, col. 1:10-14). The background section notes the difficulty in identifying compounds that selectively inhibit specific Cdk proteins without affecting other enzymes, which can lead to undesirable side effects (’612 Patent, col. 2:20-29).
- The Patented Solution: The invention provides substituted 2-aminopyridine compounds that potently inhibit Cdk4 (’612 Patent, Abstract). Specifically, the patent discloses a class of compounds based on a 2-(pyridin-2-ylamino)-pyrido[2,3-d]pyrimidin-7-one core structure, with claim 1 reciting a single, specific compound with defined chemical substituents (’612 Patent, col. 2:36-67, cl. 1).
- Technical Importance: The claimed compounds function as inhibitors of cyclin-dependent kinases, which are key regulators of the cell cycle and have been identified as important targets for developing anti-cancer therapies (’612 Patent, col. 1:15-28).
Key Claims at a Glance
- The complaint asserts independent claim 1 and dependent claim 2 (Compl. ¶ 27).
- Claim 1: Recites a single chemical entity:
- 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: recites a pharmaceutical composition comprising a therapeutically effective amount of 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
The Invention Explained
- Problem Addressed: Similar to the ’612 Patent from the same family, the ’489 Patent is directed to developing potent and selective inhibitors of Cdk4 to treat cell proliferative diseases, including cancer (’489 Patent, col. 1:10-14, col. 2:20-30).
- The Patented Solution: The invention provides a genus of compounds that inhibit Cdk4, defined by a Markush chemical structure based on the same 2-(pyridin-2-ylamino)-pyrido[2,3-d]pyrimidin-7-one core (’489 Patent, Abstract). The claims define a range of possible substituents at various positions on the core structure, thereby covering a family of related compounds rather than a single entity (’489 Patent, col. 2:50-67).
- Technical Importance: The patent claims a class of Cdk inhibitors, providing broader protection for related chemical structures with potential therapeutic utility in oncology (’489 Patent, col. 1:15-28).
Key Claims at a Glance
- The complaint asserts claims 1-7 and 9, with claim 1 being the independent claim (Compl. ¶ 66).
- Claim 1: Recites a chemical genus according to Formula I, which includes the following key structural variables:
- A core pyrido[2,3-d]pyrimidin-7-one structure.
- An R¹ substituent at the 5-position, defined as including C1-C6 alkyl.
- An R² substituent at the 6-position, defined as including C(O)R⁵, where R⁵ can be C1-C8 alkyl.
- An R³ substituent at the 8-position, defined as including C3-C7 cycloalkyl.
- A substituted pyridin-2-ylamino group at the 2-position, where substituents X¹, X², and X³ can be selected from a list that includes hydrogen and groups that form a piperazinyl ring.
U.S. Patent No. 7,456,168 - 2-(pyridin-2-ylamino)-pyrido [2,3-d]pyrimidin-7-ones
The Invention Explained
- This patent claims a method of treating breast cancer in a mammal. The claimed solution involves administering an effective amount of a compound falling within the genus defined by Formula I, which is the same genus claimed in the ’489 Patent (Compl. ¶ 101; ’168 Patent, cl. 1). The accused feature is the future use of Defendant's ANDA Product for treating breast cancer, an infringement that Plaintiff alleges will be induced by Defendant's proposed product labeling upon FDA approval (Compl. ¶¶ 105, 110-111).
Key Claims at a Glance
- The complaint asserts claims 1-4, with claim 1 being the independent method claim (Compl. ¶ 105).
III. The Accused Instrumentality
Product Identification
- Defendant's generic Palbociclib capsules (75 mg, 100 mg, and 125 mg), for which Defendant submitted ANDA No. 213093 to the FDA seeking approval for commercial sale (Compl. ¶ 2). The branded version of this drug is Plaintiff's IBRANCE® (Compl. ¶ 1).
Functionality and Market Context
- Palbociclib is a kinase inhibitor approved for the treatment of certain types of breast cancer (Compl. ¶ 101). The complaint alleges that Plaintiff's IBRANCE® product is covered by the patents-in-suit and is listed in the FDA's Orange Book (Compl. ¶¶ 24, 63, 102). The act of infringement alleged in the complaint is the submission of the ANDA itself, which seeks approval to market a generic version of IBRANCE® prior to the expiration of the patents-in-suit (Compl. ¶ 29).
IV. Analysis of Infringement Allegations
No probative visual evidence provided in complaint.
U.S. Patent No. 6,936,612 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. | Defendant's ANDA Product is a pharmaceutical composition containing Palbociclib, which is the specific chemical compound recited in claim 1. | ¶27 | col. 47:1-6 |
U.S. Patent No. 7,208,489 Infringement Allegations
| Claim Element (from Independent Claim 1) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| A compound of Formula I... | Defendant's ANDA Product contains Palbociclib, a compound that falls within the scope of the chemical genus defined by Formula I. | ¶66 | col. 47:1-4 |
| ...wherein R¹ is... C₁-C₆ alkyl... | The Palbociclib compound has a methyl group at the R¹ position. | ¶66 | col. 47:62-64 |
| ...wherein R³ is... C₃-C₇ cycloalkyl... | The Palbociclib compound has a cyclopentyl group at the R³ position. | ¶66 | col. 48:62-63 |
| ...wherein R² is... COR⁵... | The Palbociclib compound has an acetyl group (C(O)CH₃) at the R² position. | ¶66 | col. 48:1-12 |
| ...wherein one of X¹, X², and X³ is... NRR⁶, which may form a heterocyclic ring... | The Palbociclib compound has a piperazin-1-yl group attached to the pyridin-2-ylamino moiety. | ¶66 | col. 47:20-25 |
Identified Points of Contention
- Validity vs. Claim Scope: The complaint alleges that Defendant's notice letter did not contest that its product meets the limitations of the asserted claims, but instead asserted that the claims are invalid or unenforceable (Compl. ¶¶ 28, 67, 106). This suggests the central dispute may concern patent validity rather than the technical scope of the claims as applied to the accused product.
- Statutory Infringement: The act of infringement is statutory, arising under 35 U.S.C. § 271(e)(2) from the submission of an ANDA for a drug claimed in a patent or for a use claimed in a patent. A key legal question for the court is whether this submission constitutes infringement of each of the asserted patents.
V. Key Claim Terms for Construction
The complaint does not provide sufficient detail to identify specific claim terms that are likely to be central to a claim construction dispute. The asserted claim of the ’612 Patent recites a single chemical compound by its specific IUPAC name, which may limit the scope for interpretation. The asserted claims of the ’489 Patent recite a chemical genus, but the complaint does not suggest a dispute over the boundaries of the recited Markush groups as they apply to the accused product.
VI. Other Allegations
- Indirect Infringement: The complaint alleges active inducement of infringement of all three patents. This allegation is based on the assertion that Defendant knows its product and proposed labeling are adapted for infringing uses and that the labeling will instruct physicians and patients to use the product in a manner that infringes the claims, particularly the method-of-use claims of the '168 Patent (Compl. ¶¶ 33, 72, 111). Contributory infringement is also alleged on the basis that the product is not a staple article of commerce suitable for substantial non-infringing use (Compl. ¶¶ 34, 73, 112).
- Willful Infringement: The complaint alleges that Defendant has acted with full knowledge of the patents-in-suit, citing Defendant's notice letter of March 20, 2019, as evidence of pre-suit knowledge. It further alleges Defendant acted without a reasonable basis for believing it would not be liable for infringement (Compl. ¶¶ 37, 76, 115).
VII. Analyst’s Conclusion: Key Questions for the Case
- A central issue will be one of patent validity: as the complaint alleges infringement is not factually contested, the case will likely focus on whether the asserted claims of the patents-in-suit are valid over the prior art that Defendant will be expected to present.
- A key question for the remedy phase will be the scope of relief: Plaintiff seeks not only a declaration of infringement based on the ANDA submission but also an injunction to prevent future commercialization and an order setting the effective date of any FDA approval to be no earlier than the latest expiration date of the patents-in-suit.
- A secondary legal question will be one of inducement: specifically for the '168 method-of-use patent, the court will likely examine whether Defendant's proposed product labeling provides sufficient evidence of specific intent to encourage direct infringement by end-users.