DCT
2:23-cv-02467
Epitopix LLC v. Zoetis Inc
I. Executive Summary and Procedural Information
- Parties & Counsel:
- Plaintiff: Epitopix, LLC d/b/a Vaxxinova US (Minnesota)
- Defendant: Zoetis Inc. (Delaware)
- Plaintiff’s Counsel: Fisherbroyles, LLP
- Case Identification: 2:23-cv-02467, D.N.J., 05/04/2023
- Venue Allegations: Venue is based on allegations that Defendant resides in the district, has committed acts of infringement there, and maintains a physical place of business in the district.
- Core Dispute: Plaintiff alleges that Defendant’s animal vaccine product lines infringe a patent related to immunizing compositions derived from gram-negative microbes.
- Technical Context: The technology relates to veterinary vaccines that use specific bacterial proteins, known as siderophore receptor proteins (SRPs), to generate a broad immune response against various bacterial infections in livestock and poultry.
- Key Procedural History: The complaint alleges a long commercial relationship between the parties (including Defendant's predecessor, Pfizer), involving licensing discussions, due diligence, and a Development, Commercialization, and Supply Agreement that was in effect from May 2010 until it terminated on January 1, 2021. The patent-in-suit expired on January 3, 2022, limiting any potential recovery to past damages. Plaintiff alleges it sent a notice of infringement letter on November 29, 2022, after which the parties entered a tolling agreement.
Case Timeline
| Date | Event |
|---|---|
| 2001-01-03 | '048 Patent Priority Date |
| 2003-10-01 | Plaintiff and Defendant's predecessor (Pfizer) began discussions |
| 2010-05-01 | Pfizer and Epitopix entered a Development and License Agreement |
| 2012-02-01 | Re-launch of accused Enviracor® J-5 product |
| 2013-01-01 | Zoetis became an independent company from Pfizer |
| 2014-01-28 | U.S. Patent No. 8,637,048 Issued |
| 2021-01-01 | Parties' Development and License Agreement terminated |
| 2022-01-03 | U.S. Patent No. 8,637,048 Expired |
| 2022-11-29 | Plaintiff sent notice of infringement letter to Defendant |
| 2023-01-24 | Parties entered a tolling agreement |
| 2023-05-04 | Complaint Filed |
II. Technology and Patent(s)-in-Suit Analysis
U.S. Patent No. 8,637,048 - "Immunizing Compositions and Methods of Use"
The Invention Explained
- Problem Addressed: The patent addresses the challenge of creating effective and safe veterinary vaccines against gram-negative bacteria. Conventional vaccines often cause inflammatory side effects due to the presence of lipopolysaccharides (LPS) and may lack broad protection against multiple bacterial species or strains, while methods to remove LPS are often cost-prohibitive for animal vaccines (’048 Patent, col. 1:45-62; col. 2:1-5).
- The Patented Solution: The invention describes a vaccine composition created by growing gram-negative microbes in an iron-deficient environment. This condition forces the bacteria to express high levels of specific outer-membrane proteins called siderophore receptor polypeptides (SRPs), which are used to acquire iron. The patent teaches that compositions containing these SRPs, along with other proteins called porins, can generate a broad immune response against various bacteria that rely on similar iron-uptake mechanisms, all while containing low levels of harmful LPS (’048 Patent, Abstract; col. 2:6-19).
- Technical Importance: This technology provided a method to create a single vaccine targeting a common and essential bacterial survival mechanism—iron acquisition—thereby offering the potential for broad cross-protection against multiple pathogens with improved safety (Compl. ¶¶10-11).
Key Claims at a Glance
- The complaint primarily asserts infringement of independent claim 4, while reserving the right to assert other claims (Compl. ¶¶34, 42).
- The essential elements of independent claim 4 are:
- A composition comprising: an isolated whole cell preparation of gram negative microbes, wherein the gram negative microbes comprise:
- at least two siderophore receptor polypeptides (SRPs) expressed by the gram negative microbe when the gram negative microbe is grown in the presence of 2,2-dipyridyl; and
- at least two porins; and
- a pharmaceutically acceptable carrier.
III. The Accused Instrumentality
Product Identification
The complaint accuses five of Defendant’s veterinary vaccine product lines: One Shot®, Poulvac® E. coli, Poulvac® ST, Somubac®, and Enviracor J-5 (Compl. ¶33).
Functionality and Market Context
The accused products are described as whole cell bacterin or modified live vaccines used to immunize animals such as cattle and poultry against various bacterial pathogens, including Mannheimia haemolytica, Escherichia coli, Salmonella typhimurium, and Haemophilus somnus (Compl. ¶¶34-38). The complaint alleges that Plaintiff analyzed the accused products and confirmed they contain the claimed SRPs and porins, and that Defendant incorporated the patented technology to improve the efficacy of these product lines (Compl. ¶¶29, 33).
IV. Analysis of Infringement Allegations
The complaint provides a series of claim charts alleging that each of the five accused product lines infringes at least claim 4 of the '048 Patent. The complaint presents a claim chart for the One Shot® product that juxtaposes the claim elements with the product's alleged features (Compl. ¶34). The core allegations are summarized below.
'048 Patent Infringement Allegations
| Claim Element (from Independent Claim 4) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| A composition comprising: an isolated whole cell preparation of gram negative microbes, wherein the gram negative microbes comprise: | One Shot® is a whole cell bacterin of Mannheimia haemolytica, which is a gram negative microbe. | ¶34 | col. 4:30-49 |
| at least two siderophore receptor polypeptides (SRPs) expressed by the gram negative microbe when the gram negative microbe is grown in the presence of 2,2-dipyridyl; and | One Shot® includes at least the following SRPs: Transferrin Binding Protein TbpA (106 kDa), Hemogloblin Receptor Protein (93kDa), OMR Hemogloblin Receptor Protein (79kDa), Outer Membrane Siderophore Receptor (78kDa), and Ferric Enterobactin Receptor Protein (77kDa). The complaint alleges these proteins are the claimed SRPs based on product analysis. | ¶34 | col. 6:29-44 |
| at least two porins; and | One Shot® includes at least the following porins: OMP P2 (41kDa) and OMP Heat Modifiable PomA (40 kDa). | ¶34 | col. 7:45-49 |
| a pharmaceutically acceptable carrier. | One Shot® is prepared in a formulation for administration to animals which includes a pharmaceutically acceptable carrier. | ¶34 | col. 10:16-19 |
Identified Points of Contention
- Scope Questions: Claim 4 contains a product-by-process limitation: the microbes must be "grown in the presence of 2,2-dipyridyl." The complaint's allegations appear to be based on analysis of the final products, not direct evidence of Defendant's manufacturing methods (Compl. ¶33). This raises the question of whether the mere presence of certain SRPs in the accused vaccines is sufficient to prove they were made by the claimed process. The defense may argue that other methods of inducing iron-starvation could yield similar proteins without using 2,2-dipyridyl.
- Technical Questions: The infringement case relies on the assertion that proteins found in the accused products, such as "Transferrin Binding Protein TbpA," are in fact "siderophore receptor polypeptides" as that term is defined in the patent. A technical dispute may arise over whether these specific proteins meet the functional requirements of an SRP as described in the patent, which defines them by their expression under iron-limiting conditions and their role as receptors for iron-binding siderophores (’048 Patent, col. 5:26-36).
V. Key Claim Terms for Construction
"siderophore receptor polypeptides (SRPs)"
- Context and Importance: This term is central to the invention. The outcome of the infringement analysis depends on whether the specific proteins identified in Defendant's products fall within the scope of this term.
- Intrinsic Evidence for a Broader Interpretation: The specification provides a functional definition, describing SRPs as polypeptides expressed at high levels in low-iron conditions and substantially lower levels in high-iron conditions, which act as receptors for iron-binding molecules (’048 Patent, col. 5:26-36). This could support a broad construction covering any protein that meets this functional test.
- Intrinsic Evidence for a Narrower Interpretation: The patent provides specific examples of SRPs from various bacteria and lists their typical molecular weights, generally between 60 kDa and 100 kDa (’048 Patent, col. 6:29-44). A party could argue the term should be limited to the types and molecular weight ranges of the SRPs disclosed in these embodiments.
"grown in the presence of 2,2-dipyridyl"
- Context and Importance: This product-by-process limitation defines how the key components of the claimed composition are produced. Practitioners may focus on this term because infringement could hinge on whether Plaintiff must prove Defendant's actual manufacturing process or if the product's final characteristics are sufficient.
- Intrinsic Evidence for a Broader Interpretation: The patent repeatedly links the use of the iron chelator 2,2-dipyridyl to the creation of "low iron conditions" that "promote the expression of SRPs" (’048 Patent, col. 12:3-12). This could support an argument that any product exhibiting the unique SRP profile that results from such iron starvation inherently meets the claim limitation, making the process discernible from the product itself.
- Intrinsic Evidence for a Narrower Interpretation: The claim language is specific to "2,2-dipyridyl," not a general "low iron condition" or "iron chelator." This could support an argument that infringement requires proof of the use of this specific chemical, and that a product made using a different iron-starvation technique would not literally infringe.
VI. Other Allegations
Willful Infringement
The complaint alleges that Defendant’s infringement has been willful. The allegations are based on a long history of business dealings, including a prior licensing agreement, due diligence on the patented technology, and Defendant's alleged awareness of Plaintiff's patent portfolio from at least the patent's issue date (Compl. ¶¶17-21, 48). The complaint also asserts that Defendant had pre-suit knowledge of its infringement from a notice letter dated November 29, 2022 (Compl. ¶40).
VII. Analyst’s Conclusion: Key Questions for the Case
- A central issue will be one of proof: can the product-by-process limitation—that the microbes were "grown in the presence of 2,2-dipyridyl"—be satisfied by analyzing the final vaccine's protein composition, or will the court require direct evidence of the defendant's specific manufacturing steps?
- A key evidentiary question will be one of technical identity: does the analysis of the accused vaccines provide sufficient evidence that the proteins identified by Plaintiff are the same "siderophore receptor polypeptides" and "porins" as those defined and claimed by the patent, both in structure and function?
- Given the parties' extensive prior relationship and the termination of a license agreement, a significant question for trial will be one of intent: do the facts alleged, if proven, demonstrate that the alleged infringement was willful, which could expose the defendant to a risk of enhanced damages for conduct that occurred after the parties' commercial relationship ended?