American Regent Inc v. RK Pharma Inc

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: American Regent, Inc. (New York)
  • Defendant: RK Pharma, Inc. (Delaware)
  • Plaintiff’s Counsel: GIBBONS P.C.; Sterne, Kessler, Goldstein & Fox P.L.L.C.
• Case Identification: 2:24-cv-11122, D.N.J., 12/13/2024
• Venue Allegations: Plaintiff alleges venue is proper in the District of New Jersey because Defendant maintains a regular and established place of business in the state through its affiliates, has consented to venue in a related action, and submitted the accused Abbreviated New Drug Application (ANDA) from an affiliate's New Jersey location.
• Core Dispute: Plaintiff alleges that Defendant’s filing of an ANDA to market generic versions of Plaintiff's Selenious Acid injectable products constitutes an act of infringement of a patent related to stable trace element compositions for parenteral nutrition.
• Technical Context: The technology concerns injectable trace element formulations used in parenteral (intravenous) nutrition, a critical therapy for patients who cannot sufficiently absorb nutrients through their digestive systems.
• Key Procedural History: The complaint notes that this case is related to a prior action (C.A. No. 24-7805) between the same parties involving the same ANDA but a different patent. The patent-in-suit was listed in the FDA's "Orange Book" after the complaint in the related action had been filed.

Case Timeline

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

U.S. Patent No. 12,150,957 - "Trace element compositions, methods of making and use,"

• Patent Identification: U.S. Patent No. 12,150,957, "Trace element compositions, methods of making and use," issued November 26, 2024.

The Invention Explained

• Problem Addressed: The patent's background describes that when trace elements are added to parenteral nutrition (PN) solutions, the resulting mixture often has a short stability period of only 24 to 48 hours. This leads to wasted product, increased costs, and logistical challenges for patients and healthcare providers who must frequently prepare fresh admixtures ('957 Patent, col. 2:8-18). Furthermore, existing multi-element formulations are not easily customizable for individual patient needs ('957 Patent, col. 2:51-56).
• The Patented Solution: The invention provides stable, injectable trace element compositions, such as those containing selenium, that are designed to remain stable for longer periods when added to PN solutions. This extended stability aims to reduce admixing frequency, minimize waste, and allow for the preparation of PN solutions in larger, more efficient batches ('957 Patent, col. 2:31-45; Abstract).
• Technical Importance: By creating more stable formulations, the invention sought to reduce the significant costs and logistical burdens associated with intravenous feeding therapies for critically ill patients or those with long-term nutritional needs ('957 Patent, col. 2:12-24).

Key Claims at a Glance

• The complaint asserts infringement of "one or more claims" of the '957 patent without further specification (Compl. ¶30).
• Independent claim 1, a representative method claim, recites the following essential elements:
  • A method of providing an injectable composition to a patient in need thereof, the method comprising administering at least the injectable composition to the patient,
  • the injectable composition comprising water,
  • 6 µg, 40 µg or 60 µg of selenium,
  • no chromium or chromium in an amount not to exceed 1 µg,
  • no aluminum or aluminum in an amount not to exceed 6 µg,
  • no iron or iron in an amount not to exceed 10 µg,
  • and fluoride in an amount of 0.0001 µg to 2.7 µg per 1 mL of the injectable composition.

III. The Accused Instrumentality

Product Identification

• The accused products are RK Pharma's generic Selenious Acid products for which it seeks FDA approval under ANDA No. 218536 (Compl. ¶1).

Functionality and Market Context

• The ANDA Products are alleged to be generic versions of American Regent's approved Selenious Acid products, intended for use as a source of selenium in parenteral nutrition (Compl. ¶1, ¶24). The complaint states the ANDA Products contain the "same or equivalent ingredients in the same or equivalent amounts" as the reference listed drugs (Compl. ¶24, ¶26).
• The complaint identifies three proposed concentrations for the ANDA Products: Selenious Acid (eq. 12 mcg Selenium/2mL (eq. 6 mcg Selenium/mL)); Selenious Acid (eq. 60 mcg Selenium/mL); and Selenious Acid (eq. 600 mcg Selenium/10 mL (eq. 60 mcg Selenium/mL)) (Compl. ¶25).

No probative visual evidence provided in complaint.

IV. Analysis of Infringement Allegations

The complaint does not provide a claim chart exhibit. The following summary is based on the narrative allegations.

'957 Patent Infringement Allegations

Identified Points of Contention

• Technical Question: The complaint's infringement theory rests on the ANDA product being a generic equivalent to the patented product. A central question will be whether discovery confirms that RK Pharma's proposed formulation actually meets the specific negative limitations for chromium, aluminum, and iron required by the asserted claims.
• Scope Question: The claims recite specific amounts of selenium (6, 40, or 60 µg/mL). The question arises whether RK Pharma's products, as manufactured, consistently fall within these claimed amounts, and how manufacturing variability might be addressed in the infringement analysis.

V. Key Claim Terms for Construction

The Term

• "no chromium or chromium in an amount not to exceed 1 µg"

Context and Importance

• This negative limitation appears to be a key feature distinguishing the invention from prior art, as the patent repeatedly emphasizes having little or no chromium ('957 Patent, col. 13:45-54; Table 35). The infringement analysis for any composition claim will directly depend on whether the accused product satisfies this low-chromium requirement.

Intrinsic Evidence for Interpretation

• Evidence for a Broader Interpretation: A party could argue that "no chromium" means no intentionally added chromium as a formulation component, and that the "not to exceed 1 µg" clause provides the operative ceiling for any unavoidable trace contaminants.
• Evidence for a Narrower Interpretation: The disjunctive "or" could suggest two separate, patentable embodiments: one with absolutely zero detectable chromium, and a second with a measurable amount that is still below 1 µg. The specification's statement that "the injectable composition of this disclosure does not contain any detectable chromium or no chromium at all" could be used to support an argument for a very strict, zero-tolerance interpretation of the "no chromium" limitation ('957 Patent, col. 13:49-51).

VI. Other Allegations

Indirect Infringement

• The complaint alleges induced infringement, stating that RK Pharma's proposed package insert will instruct medical professionals and patients to use the ANDA product in an infringing manner (Compl. ¶30). It also alleges contributory infringement, asserting that the product is not suitable for substantial non-infringing use and is especially made for use in an infringing manner (Compl. ¶31).

Willful Infringement

• Willfulness is alleged based on pre-suit knowledge. The complaint claims RK Pharma knew of the '957 patent since at least October 11, 2024, approximately two months before the lawsuit was filed, based on an email from Plaintiff's counsel (Compl. ¶33). The complaint also seeks a finding that the case is 'exceptional' under 35 U.S.C. § 285 (Compl. ¶34).

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

• A central issue will be one of compositional identity: will the evidence show that RK Pharma's proposed generic product, as formulated for its ANDA, meets the specific positive limitations for selenium concentration and, critically, the negative limitations for the near-absence of chromium, aluminum, and iron as required by the asserted claims?
• A key legal question will be one of induced infringement: does the proposed product label for RK Pharma's generic Selenious Acid, as submitted in its ANDA, contain instructions that would inevitably lead medical practitioners to administer the product in a manner that practices all steps of the asserted method claims?