DCT
1:25-cv-00079
Eagle Pharma Inc v. Baxter Healthcare Corp
I. Executive Summary and Procedural Information
- Parties & Counsel:
- Plaintiff: Eagle Pharmaceuticals, Inc. and Eagle Sub1 LLC (Delaware)
- Defendant: Baxter Healthcare Corporation (Delaware)
- Plaintiff’s Counsel: McCARTER & ENGLISH, LLP
- Case Identification: 1:25-cv-00079, D. Del., 04/07/2025
- Venue Allegations: Venue is alleged to be proper in the District of Delaware because the Defendant is a Delaware corporation and therefore resides in the district.
- Core Dispute: Plaintiff alleges that Defendant’s bendamustine hydrochloride injection product infringes a patent related to long-term, stable liquid formulations of the chemotherapy drug bendamustine.
- Technical Context: The technology addresses the chemical instability of bendamustine in aqueous solutions by creating a ready-to-use liquid formulation that avoids the need for inconvenient and time-sensitive reconstitution from a lyophilized powder.
- Key Procedural History: The complaint alleges that Defendant was aware of the patent-in-suit’s family through prior litigation involving a related patent, Eagle Pharms., Inc. v. Celerity Pharms., LLC, C.A. No. 22-42-CFC (D. Del.). Plaintiff also alleges it provided Defendant with notice of the asserted patent’s issuance on the day it issued. The patent-in-suit is listed in the FDA’s Orange Book for Plaintiff’s BELRAPZO® and BENDEKA® products.
Case Timeline
| Date | Event |
|---|---|
| 2010-01-28 | Earliest Priority Date for ’248 Patent |
| 2018-05-15 | FDA Approval of Plaintiff's BELRAPZO® Product |
| 2022-12-15 | FDA Approval of Defendant's Accused Bendamustine Product |
| 2024-11-12 | U.S. Patent No. 12,138,248 Issues |
| 2024-11-12 | Plaintiff sends notice letter to Defendant regarding the ’248 Patent |
| 2025-04-07 | First Amended Complaint Filed |
II. Technology and Patent(s)-in-Suit Analysis
U.S. Patent No. 12,138,248 - "Formulations of Bendamustine"
- Patent Identification: U.S. Patent No. 12,138,248, "Formulations of Bendamustine", issued November 12, 2024.
The Invention Explained
- Problem Addressed: The patent’s background section explains that bendamustine, a potent chemotherapy agent, is subject to rapid degradation via hydrolysis when in aqueous solution, making liquid storage impractical (’248 Patent, col. 1:49-54). Commercially available versions were therefore supplied as a lyophilized (freeze-dried) powder that required reconstitution before administration, a process described as clinically inconvenient (’248 Patent, col. 1:65-67).
- The Patented Solution: The invention provides a ready-to-use, long-term storage-stable liquid formulation of bendamustine (’248 Patent, Abstract). This is achieved by dissolving bendamustine in a "pharmaceutically acceptable fluid" containing specific non-aqueous solvents, such as polyethylene glycol (PEG), and including a "stabilizing amount of an antioxidant" (’248 Patent, col. 3:1-5). The specification notes that using PEG is particularly advantageous because its hydroxide group is less reactive than that of other solvents like propylene glycol, resulting in a slower rate of degradation over extended periods (’248 Patent, col. 4:57-64).
- Technical Importance: The invention provides a formulation that avoids the need for on-site reconstitution, offering improved convenience and potentially reducing errors and chemical instability associated with the reconstitution process (’248 Patent, col. 2:24-26).
Key Claims at a Glance
- The complaint asserts infringement of one or more claims, with a focus on independent claim 1 (Compl. ¶41).
- Independent Claim 1 of the ’248 Patent recites the following essential elements:
- A sterile container with a liquid bendamustine composition.
- The composition contains bendamustine (or a salt) at a concentration of about 25 mg/mL.
- The composition contains a pharmaceutically acceptable fluid "consisting of" polyethylene glycol and optionally one or more of propylene glycol, ethanol, benzyl alcohol, and glycofurol.
- The composition contains a stabilizing amount of an antioxidant.
- The composition has less than 5% total impurities (determined by HPLC) after storage for at least 15 months at a temperature between 5° C and 25° C.
III. The Accused Instrumentality
Product Identification
- The accused instrumentality is "Baxter's Bendamustine Product," an injection product approved under New Drug Application (NDA) No. 216078 (Compl. ¶1).
Functionality and Market Context
- The accused product is a liquid solution of bendamustine hydrochloride intended for intravenous administration after dilution (Compl. ¶23, ¶26, ¶27).
- It is supplied in a multiple-dose vial at a dosage strength of 25 mg/mL (Compl. ¶24, ¶25).
- The complaint alleges, based on the product’s approved label, that it contains polyethylene glycol, ethanol, and the antioxidant monothioglycerol (Compl. ¶28, ¶34).
- The product is marketed for the treatment of chronic lymphocytic leukemia, a use for which Plaintiff’s own bendamustine product is approved (Compl. ¶39, ¶15).
IV. Analysis of Infringement Allegations
No probative visual evidence provided in complaint.
Claim Chart Summary
| Claim Element (from Independent Claim 1) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| A sterile container containing a liquid bendamustine-containing composition | Defendant's product is a liquid solution supplied in a sterile, multiple-dose vial. | ¶25, ¶26 | col. 15:19-21 |
| bendamustine, or a pharmaceutically acceptable salt thereof, wherein the bendamustine concentration in the composition is about 25 mg/mL | Defendant's product contains bendamustine hydrochloride at a dosage strength of 25 mg/mL. | ¶23, ¶24 | col. 15:22-25 |
| a pharmaceutically acceptable fluid consisting of polyethylene glycol and optionally one or more of propylene glycol, ethanol, benzyl alcohol and glycofurol | Defendant's product contains polyethylene glycol and ethanol as part of its fluid. | ¶28 | col. 15:26-29 |
| a stabilizing amount of an antioxidant | Defendant's product contains monothioglycerol, which is identified on the label as an antioxidant. | ¶34 | col. 15:30-30 |
| wherein the total impurities...is less than about 5%...after at least about 15 months at a temperature of about 5° C. to about 25° C. | On information and belief, the product meets this stability requirement, as evidenced by its FDA-approved 18-month shelf life. | ¶35, ¶37 | col. 15:31-37 |
Identified Points of Contention
- Scope Questions: A primary dispute may arise from the claim term "consisting of." The complaint notes that the accused product's label states sodium hydroxide is used "to adjust the acidity" of the polyethylene glycol (Compl. ¶29). The complaint preemptively argues this does not add a component to the claimed fluid because the sodium hydroxide is consumed, not present in every batch, or is otherwise not a component of the final product (Compl. ¶31, ¶32). This raises the question of whether the use of a processing aid not listed in a "consisting of" claim element removes the final product from the scope of the claim.
- Technical Questions: The complaint's allegation that the accused product meets the specific impurity limitation appears to be based on inference from the product's FDA-approved 18-month shelf life, rather than direct test data (Compl. ¶37). This raises an evidentiary question: does the approved shelf life necessarily prove that the product meets the specific quantitative impurity and storage condition requirements of Claim 1?
V. Key Claim Terms for Construction
The Term: "consisting of"
- Context and Importance: This term appears in Claim 1 to define the components of the "pharmaceutically acceptable fluid." In patent law, "consisting of" is a closed-ended term, meaning that the claimed fluid cannot contain other unlisted ingredients. The infringement analysis will critically depend on whether the sodium hydroxide mentioned in the accused product's label is considered a component of the final fluid formulation, thereby placing it outside the claim's scope.
- Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: A party may argue that the term applies only to the active solvents and excipients that make up the bulk of the final fluid, not to processing aids like pH adjusters that may be consumed during manufacturing and not be present in the final product. The complaint makes this argument, alleging the sodium hydroxide is "consumed in that reaction" (Compl. ¶32).
- Evidence for a Narrower Interpretation: A party may argue for the strict, traditional interpretation where the presence of any unlisted ingredient, even in trace amounts, avoids infringement. The patent claims a specific list of acceptable components for the fluid and does not mention pH adjusters ('248 Patent, col. 15:26-29). The patent’s detailed description also focuses on the listed solvents and antioxidants without discussing other potential additives.
The Term: "a stabilizing amount"
- Context and Importance: The claim requires a "stabilizing amount of an antioxidant." While the accused product contains an antioxidant (monothioglycerol), the question of whether the amount present is "stabilizing" as defined by the patent will be a point of proof. Practitioners may focus on this term because its definition is tied to the patent's overall goal of achieving long-term stability.
- Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The specification describes "stabilizing amount" as "those amounts which increase or enhance the stability of the bendamustine in the compositions" ('248 Patent, col. 4:2-5). This functional definition could be argued to cover any amount that provides a measurable stability benefit.
- Evidence for a Narrower Interpretation: The specification provides specific concentration ranges for suitable antioxidants (e.g., "from about 2.5 mg/mL to about 35 mg/mL") and a specific example of 5 mg/mL ('248 Patent, col. 4:9-13). A party may argue that "stabilizing amount" should be construed to fall within or near these explicitly disclosed ranges.
VI. Other Allegations
- Indirect Infringement: The complaint alleges induced infringement, stating that Defendant’s product label "encourages, recommends, instructs, and/or promotes administration to patients" with certain cancers, thereby inducing infringing use of the claimed composition by healthcare providers (Compl. ¶39, ¶43).
- Willful Infringement: The willfulness allegation is based on alleged pre-suit knowledge of the patent and its infringement. The complaint alleges that Defendant was put on notice via a letter from Plaintiff on the day the patent issued (Compl. ¶44). It further alleges that Defendant was aware of Plaintiff's patent portfolio due to involvement in prior litigation over a related patent and that Defendant "has regularly monitored Eagle’s patent filings" (Compl. ¶44).
VII. Analyst’s Conclusion: Key Questions for the Case
- A core issue will be one of definitional scope: can the term "consisting of," which creates a presumptively closed list of ingredients for the claimed fluid, be construed to cover a product made using an unlisted pH adjuster? The outcome may depend on whether the adjuster is proven to be present as a component in the final product.
- A key evidentiary question will be one of functional proof: does the accused product meet the specific "impurity limitation" of Claim 1 (less than 5% impurities after 15 months at 5-25° C)? The complaint infers this from the product’s FDA-approved shelf life, but this will likely require factual development and testing during discovery to resolve.