DCT

1:24-cv-00268

American Regent Inc v. RK Pharma Inc

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I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 1:24-cv-00268, D. Del., 02/29/2024
  • Venue Allegations: Venue is alleged to be proper in the District of Delaware because Defendants RK Pharma, Inc., Apicore US LLC, and Archis Pharma LLC are incorporated or organized under the laws of Delaware. Plaintiff further alleges the defendants operate as a "vertically integrated" business, establishing a regular place of business for all defendants in the district.
  • Core Dispute: Plaintiff alleges that Defendants' submission of an Abbreviated New Drug Application (ANDA) to the FDA, seeking approval to market generic versions of Plaintiff's Tralement® and Multrys® products, constitutes an act of patent infringement under the Hatch-Waxman Act.
  • Technical Context: The lawsuit concerns sterile, injectable multi-trace element compositions used to provide essential minerals like zinc, copper, selenium, and manganese to patients requiring parenteral (intravenous) nutrition.
  • Key Procedural History: The lawsuit was initiated following a notification letter dated January 23, 2024, in which Defendants informed Plaintiff of their ANDA filing containing a Paragraph IV Certification. This certification asserts that the patent-in-suit is either invalid or will not be infringed by the proposed generic products. The patent-in-suit is listed in the FDA's "Orange Book" as covering Plaintiff's Tralement® and Multrys® drug products.

Case Timeline

Date Event
2020-07-02 Earliest Priority Date for '548 Patent
2020-07-02 FDA Approval Date for Plaintiff's Tralement® and Multrys®
2023-10-17 U.S. Patent No. 11,786,548 Issues
2024-01-23 Defendants' Paragraph IV Notice Letter Sent to Plaintiff
2024-02-29 Complaint Filed
2041-07-01 '548 Patent Expiration Date

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

U.S. Patent No. 11,786,548 - "Trace element compositions, methods of making and use"

  • Patent Identification: U.S. Patent No. 11,786,548, "Trace element compositions, methods of making and use," issued October 17, 2023.

The Invention Explained

  • Problem Addressed: The patent's background section describes challenges with existing trace element supplements for parenteral nutrition, including short chemical stability (typically 24-48 hours) after being mixed, which leads to product waste, increased costs, and inconvenience for caregivers ('548 Patent, col. 2:1-17). Additionally, existing combination products often contain higher-than-necessary doses of certain elements, making it difficult to customize treatment for individual patient needs ('548 Patent, col. 2:49-55).
  • The Patented Solution: The invention is a stable, injectable trace element composition that, when added to a parenteral nutrition solution, remains stable for a longer period (e.g., up to 14 days under refrigeration) ('548 Patent, col. 4:1-3). This extended stability allows for the preparation of nutrition bags in larger batches, reducing waste and the frequency of admixing ('548 Patent, col. 2:31-48). The patent describes specific formulations with particular concentrations of zinc, copper, selenium, and manganese, and a controlled acidic pH (e.g., 1.5 to 3.5), which contributes to stability ('548 Patent, col. 12:1-25, Table 1; col. 14:1-2).
  • Technical Importance: By improving the stability and offering specific formulations, the invention provides a more economical and convenient method for administering essential trace elements in long-term parenteral nutrition therapy ('548 Patent, col. 2:31-39).

Key Claims at a Glance

  • The complaint identifies a wide range of claims potentially at issue, with Independent Claim 1 being representative of the adult/pediatric formulation (Compl. ¶51).
  • Independent Claim 1 requires:
    • An injectable composition comprising water, about 60 µg of selenium, 3,000 µg of zinc, about 300 µg of copper, and about 55 µg of manganese per 1 mL.
    • The composition contains 0 µg per 1 mL to about 10 µg per 1 mL of iron.
    • The composition does not contain any vitamins.
    • The composition contains no added chromium and no aluminum, or aluminum in an amount not to exceed 6 µg per 1 mL.
  • The complaint notes that the Defendants' Notice Letter did not assert non-infringement for numerous claims, including dependent claims, suggesting Plaintiff may assert them later (Compl. ¶51).

III. The Accused Instrumentality

Product Identification

  • The accused instrumentalities are Defendants' proposed generic drug products ("the ANDA Products") described in ANDA No. 218537 (Compl. ¶1). These include generic versions of Plaintiff's Tralement® and Multrys® products (Compl. ¶53).

Functionality and Market Context

  • The complaint alleges the ANDA Products are injectable trace element compositions intended for parenteral nutrition (Compl. ¶1). Based on the Notice Letter, the complaint specifies the formulation for the generic Tralement® version as "containing 3 mg of zinc, 0.3 mg of copper, 55 mcg of manganese, and 60 mcg of selenium" per mL (Compl. ¶54). The generic Multrys® version is alleged to contain "1000 mcg of zinc, 60 mcg of copper, 3 mcg of manganese, and 6 mcg of selenium" (Compl. ¶54).
  • The complaint alleges that the defendants, collectively "the RK Pharma Group," operate as a "vertically integrated" business engaged in all phases of the generic pharmaceutical market (Compl. ¶30). To support this, the complaint provides a screenshot from the RK Pharma Inc. website depicting the corporate relationship between the defendant entities (Compl. p. 10, fig.).

IV. Analysis of Infringement Allegations

'548 Patent Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
An injectable composition comprising water, about 60 µg of selenium, 3,000 µg of zinc, about 300 µg of copper, and about 55 µg of manganese per 1 mL... The generic Tralement® ANDA Product is an injectable composition alleged to contain "3 mg [3,000 µg] of zinc, 0.3 mg [300 µg] of copper, 55 mcg of manganese, and 60 mcg of selenium." ¶54 col. 12:1-25, Table 1
...wherein the injectable composition contains 0 µg per 1 mL to about 10 µg per 1 mL of iron... The complaint alleges the ANDA Products are generic versions of Tralement® and will feature the same or equivalent chemical properties. The patent discloses that its embodiments contain iron within this range. ¶53, ¶56 col. 46:27-29
...does not contain any vitamins... The complaint does not provide sufficient detail for analysis of this element, but alleges the ANDA products are generic versions of the reference listed drugs, which are embodiments of the patent that do not contain vitamins. ¶44, ¶53 col. 45:56-59
...contains no added chromium and no aluminum or aluminum in an amount not to exceed 6 µg per 1 mL of the injectable composition. The complaint alleges the ANDA Products will possess the same or equivalent chemical properties as the patented invention, which has no added chromium and contains aluminum below the claimed threshold. ¶56 col. 45:60-64
  • Identified Points of Contention:
    • Scope Questions: The complaint's allegations for the generic Tralement® product map directly onto the quantities recited in Claim 1. However, a primary dispute may arise over the term "about". The court will need to determine the permissible range of deviation from the recited values (e.g., 3,000 µg of zinc) that this term allows. A related question is the scope of the negative limitation "no added chromium". A dispute may arise over whether this term prohibits any detectable chromium, or only the intentional inclusion of chromium as a formulation ingredient, while still permitting trace amounts as impurities from other components.
    • Technical Questions: A key evidentiary question will be whether the final, manufactured ANDA Products contain any elemental impurities (such as iron or chromium) and at what levels. The complaint alleges the ANDA Products are equivalent to the patented embodiments, but discovery will be needed to confirm the precise composition and impurity profile of the defendants' proposed products (Compl. ¶56).

V. Key Claim Terms for Construction

  • The Term: "about"

  • Context and Importance: This term modifies every quantity of the active ingredients in Claim 1. Its construction is critical because even a minor deviation in the concentration of zinc, copper, selenium, or manganese in the defendants' product could place it outside the literal scope of the claim if "about" is construed narrowly. Practitioners may focus on this term because it is a common source of litigation and its scope can be case-dispositive.

  • Intrinsic Evidence for Interpretation:

    • Evidence for a Broader Interpretation: The term is used repeatedly, suggesting the patentee intended some flexibility. The specification describes the invention in general terms of providing trace elements, which may support a reading that is not strictly tied to the exact numbers.
    • Evidence for a Narrower Interpretation: The patent provides highly specific formulations, including a detailed table of quantities for an exemplary embodiment (Table 1, '548 Patent, col. 12:10-25). The patent also distinguishes its "lower daily doses" from prior art, suggesting that "about" may not be interpreted so broadly as to encompass those higher, prior art amounts ('548 Patent, col. 2:42-48).

  • The Term: "no added chromium"

  • Context and Importance: This negative limitation defines what is not in the composition. Its construction is central because if the defendants' product contains any detectable chromium, the infringement analysis will hinge on whether that chromium was "added." This is particularly relevant as other claims in the patent explicitly contemplate the presence of chromium as an impurity.

  • Intrinsic Evidence for Interpretation:

    • Evidence for a Broader Interpretation (i.e., less restrictive on the patentee): A party could argue this term means only that chromium is not included as an active or intended ingredient in the formulation recipe, without precluding its incidental presence as a trace impurity from other raw materials.
    • Evidence for a Narrower Interpretation (i.e., more restrictive on the patentee): The existence of other claims that explicitly permit chromium as an impurity (e.g., Claim 21, which allows chromium "in an amount not to exceed 1 µg per 1 mL") suggests that when the patentee said "no added chromium" in Claim 1, it intended a stricter standard, potentially approaching zero tolerance.

VI. Other Allegations

  • Indirect Infringement: The complaint alleges induced infringement, stating that Defendants' proposed package insert for the ANDA Products will instruct and encourage medical practitioners to administer the products in a manner that directly infringes the '548 patent (Compl. ¶59). It also alleges contributory infringement on the basis that the ANDA Products are especially made for an infringing use and are not suitable for substantial non-infringing use (Compl. ¶60).
  • Willful Infringement: The complaint alleges that the RK Pharma Group had knowledge of the '548 patent at least as of the date it submitted its ANDA with the Paragraph IV certification (Compl. ¶62). While not using the word "willful," it seeks a finding that the case is "exceptional" and requests attorneys' fees under 35 U.S.C. § 285, which is the standard pleading for such a claim (Compl. ¶63, Prayer for Relief (g)).

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

  1. A central issue will be one of definitional scope: How broadly will the term "about" be construed? The defendants' non-infringement defense may depend on whether any minor variations in their formulation's elemental concentrations fall outside the range permitted by a narrow construction of this term.
  2. A second key question will be one of technical interpretation: Does the negative limitation "no added chromium" in Claim 1 create a zero-tolerance standard, or does it merely prohibit the inclusion of chromium as an intentional ingredient, thereby permitting trace impurities? The answer will determine whether the mere presence of any detectable chromium in the ANDA product constitutes non-infringement.
  3. An evidentiary question will be whether the defendants' group of companies constitutes a "vertically integrated" enterprise to an extent that all entities are properly subject to jurisdiction and venue in Delaware and are jointly liable for the alleged infringement, as asserted by the plaintiff (Compl. ¶30, ¶35).