DCT

1:23-cv-01050

Fresenius Kabi USA LLC v. Meitheal Pharma Inc

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I. Executive Summary and Procedural Information

Case Timeline

Date Event
2003-07-10 ’010 Patent Priority Date
2013-07-02 ’010 Patent Issue Date
2020-01-16 USPTO cancels several claims of ’010 Patent after IPR
2023-08-11 Defendant sends First Notice Letter of ANDA filing to Plaintiff
2023-08-29 Defendant sends Second Notice Letter to Plaintiff
2023-09-26 Complaint Filed
2025-06-01 ’010 Patent Expiration Date (including pediatric exclusivity)

II. Technology and Patent(s)-in-Suit Analysis

U.S. Patent No. 8,476,010 - "Propofol Formulations with Non-Reactive Container Closures"

  • Patent Identification: U.S. Patent No. 8,476,010, "Propofol Formulations with Non-Reactive Container Closures," issued July 2, 2013 (’010 Patent). (Compl. ¶24).

The Invention Explained

  • Problem Addressed: The patent describes known issues with propofol emulsions, including the risk of microbial growth and hyperlipidemia in patients due to high fat/oil content in the formulation (’010 Patent, col. 2:5-23). The inventors identified a further, unappreciated problem: when the oil content is reduced to address these issues, the propofol becomes susceptible to degradation and potency loss when it comes into contact with standard container closures, such as rubber stoppers (’010 Patent, col. 4:43-65).
  • The Patented Solution: The invention claims a sterile propofol composition stored in a container that has an “inert or non-reactive” closure (’010 Patent, col. 4:48-59). This inertness is defined by a specific functional requirement: when the sealed container is agitated for 16 hours under set conditions, the propofol concentration must remain at least 93% of its starting value (’010 Patent, col. 27:63-col. 28:1). The asserted claims further narrow the closure to specific materials, such as metal or certain siliconized rubbers (’010 Patent, col. 28:1-4).
  • Technical Importance: This solution enables the use of low-oil propofol formulations, which can offer safety benefits, by overcoming the previously unrecognized chemical stability problem caused by the interaction between low-oil propofol and container closures (’010 Patent, col. 4:50-59).

Key Claims at a Glance

  • The complaint asserts infringement of "one or more claims of the '010 patent, for example, at least claim 21" (Compl. ¶37). Claim 21 is a dependent claim which incorporates all the limitations of independent claim 1.
  • Essential elements of Independent Claim 1 (as incorporated by Claim 21):
    • A sterile pharmaceutical composition of propofol in a container, comprising a container with a closure and a composition.
    • The composition comprises 0.5% to 10% by weight propofol and from about 0 to about 10% by weight solvent for propofol.
    • A functional limitation wherein, after the sealed container is agitated (300-400 cycles/minute, 16 hours, room temperature), the composition maintains a propofol concentration of at least 93% of the starting concentration, as measured by HPLC.
  • Additional elements from asserted Dependent Claim 21:
    • The closure is selected from the group consisting of siliconized bromobutyl rubber, metal, and siliconized chlorobutyl rubber.
    • The closure also comprises metal.
  • The complaint does not explicitly reserve the right to assert other claims, but its "for example" language suggests it may not be limiting its assertion to Claim 21.

III. The Accused Instrumentality

Product Identification

  • Defendant’s generic Diprivan® products, identified as “Propofol Injectable Emulsion USP, 500 mg/50mL and 1000 mg/100 mL (each 10 mg/mL),” which are the subject of ANDA No. 217945 (Compl. ¶¶30-31).

Functionality and Market Context

  • The accused product is a generic version of Diprivan®, an injectable emulsion of propofol used for general anesthesia and sedation (Compl. ¶¶27-28). The act of infringement alleged is the submission of the ANDA to the FDA seeking approval to market this generic product prior to the expiration of the ’010 Patent (Compl. ¶35). The complaint alleges, upon information and belief, that the composition, container, and closure system of Defendant's product meet all the limitations of the asserted claims (Compl. ¶39). No probative visual evidence provided in complaint.

IV. Analysis of Infringement Allegations

’010 Patent Infringement Allegations

Claim Element (from Independent Claim 1 and Dependent Claim 21) Alleged Infringing Functionality Complaint Citation Patent Citation
a sterile pharmaceutical composition of propofol in a container; a container which includes a closure and a composition in the container; Defendant's generic Diprivan® products comprise a sterile pharmaceutical composition of propofol in a container with a closure. ¶39 col. 4:48-51
a composition in the container comprising from 0.5% to 10% by weight propofol and from about 0 to about 10% by weight solvent for propofol, The composition in the container comprises from 0.5% to 10% by weight propofol and from about 0 to about 10% by weight solvent for propofol. ¶39 col. 6:58-62
where when the composition in the container sealed with the closure is agitated ... the composition maintains a propofol concentration (w/v) measured by HPLC that is at least 93% of the starting concentration ... When the product is agitated under the claimed conditions, it maintains a propofol concentration of at least 93% of the starting concentration. ¶39 col. 27:63-col. 28:1
where the closure is selected from the group consisting of siliconized bromobutyl rubber, metal, and siliconized chlorobutyl rubber; The closure is selected from the group consisting of siliconized bromobutyl rubber, metal, and siliconized chlorobutyl rubber. ¶39 col. 9:46-54
and wherein the closure also comprises metal. The closure also comprises metal. ¶39 col. 10:5-6
  • Identified Points of Contention:
    • Technical Question: The complaint's allegation that Defendant's product meets the functional "at least 93%" stability limitation is made on "information and belief" (Compl. ¶39). A primary point of dispute may be factual: what evidence, such as data from tests conducted per the patent's protocol (Example 31), will be produced to demonstrate that the accused product's specific closure and formulation combination actually satisfies this performance requirement?
    • Scope Questions: Claim 21 requires the closure to be selected from a list that includes both "metal" and different types of rubber, and separately requires that the closure "also comprises metal." This dual requirement raises the question of whether a rubber stopper sealed with a separate metal crimp cap meets the claim, or if the claim requires the stopper itself to contain metal. The construction of "closure" will be critical to resolving this ambiguity.

V. Key Claim Terms for Construction

  • The Term: "closure"

    • Context and Importance: The entire invention centers on the non-reactive nature of the container's "closure". The definition of this term will determine which components of the vial sealing system are subject to the claim's material and functional limitations. For instance, whether "closure" refers only to the elastomeric stopper in direct contact with the drug product or to the entire sealing assembly (e.g., stopper plus an outer metal seal) will be critical for infringement analysis.
    • Intrinsic Evidence for a Broader Interpretation: The specification suggests the term can refer to a variety of sealing components, stating a container is "sealed with a closure, such as, for example, a rubber stopper, plunger, lid, top or the like" (’010 Patent, col. 9:37-39).
    • Intrinsic Evidence for a Narrower Interpretation: The language of Claim 21, which requires the "closure" to be selected from a group including rubber types and to "also comprise metal," could support an interpretation that the "closure" is a single, integrated unit that must meet both criteria, or a multi-component system where all parts are considered "the closure." Practitioners may focus on this potential ambiguity created by the claim's phrasing.

  • The Term: "maintains a propofol concentration ... that is at least 93% of the starting concentration"

    • Context and Importance: This functional limitation lies at the heart of the infringement question, as it quantitatively defines what it means for a closure to be "non-reactive." The case will depend on whether the accused product is shown to meet this specific performance standard.
    • Intrinsic Evidence for Interpretation: The patent provides a detailed experimental protocol for testing this property, including agitation frequency and duration (Example 31, ’010 Patent, col. 23:21-39). This detailed description provides significant intrinsic evidence for how the limitation should be evaluated, likely focusing the dispute on the factual results of testing the accused product rather than on the meaning of the term itself.

VI. Other Allegations

  • Indirect Infringement: The complaint alleges that Defendant's future commercial activities would constitute induced and contributory infringement (Compl. ¶43). The basis for inducement is that Defendant "intends to ... direct or induce others to engage, in the manufacture, use, offer for sale, sale, marketing, distribution and/or importation" of its product upon FDA approval (Compl. ¶42).
  • Willful Infringement: The complaint does not use the word "willful," but alleges that "Defendant was aware of the '010 patent prior to the submission of Defendant's ANDA" and knew that filing the ANDA was an act of infringement (Compl. ¶41). This allegation of pre-suit knowledge could form the basis for seeking enhanced damages or attorneys' fees if infringement is found after a commercial launch.

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

  • A central issue will be one of evidentiary proof: Can Fresenius demonstrate through testing that Meitheal's proposed generic product, with its particular formulation and closure system, factually meets the quantitative stability requirement of Claim 21—namely, maintaining at least 93% propofol concentration under the specific agitation conditions defined in the patent?
  • The case may also turn on a question of definitional scope: How will the court construe the term "closure" in Claim 21? Specifically, does the requirement that the closure "also comprises metal" apply to the entire sealing system (e.g., a rubber stopper plus a metal cap), or must the claimed material itself (e.g., "siliconized bromobutyl rubber") contain a metal component? The answer will determine the scope of accused products that can infringe.