DCT

1:25-cv-01107

Onyx Therap Inc v. Amneal Pharma Of New York LLC

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I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 1:25-cv-01107, D. Del., 09/04/2025
  • Venue Allegations: Plaintiff alleges venue is proper in the District of Delaware because Defendant Amneal New York is a Delaware corporation and Defendant Amneal EU is a foreign corporation subject to personal jurisdiction in the district.
  • Core Dispute: Plaintiff alleges that Defendant’s filing of a New Drug Application to market a generic version of Plaintiff’s KYPROLIS® (carfilzomib) cancer treatment constitutes an act of infringement of a patent covering the drug's formulation.
  • Technical Context: The technology relates to pharmaceutical compositions that improve the solubility and administration of proteasome inhibitors, a class of drugs used in oncology, particularly for treating multiple myeloma.
  • Key Procedural History: The complaint notes that in a prior litigation (C.A. No. 16-988-LPS), the U.S. District Court for the District of Delaware found Claim 31 of the patent-in-suit not invalid, a decision later affirmed by the U.S. Court of Appeals for the Federal Circuit. This legal history may strengthen the patent's presumption of validity in the current proceeding.

Case Timeline

Date Event
2004-12-07 ’112 Patent Priority Date
2010-06-15 U.S. Patent No. 7,737,112 Issues
2012-07-20 FDA Grants Accelerated Approval for Plaintiff's KYPROLIS®
2019-05-XX Bench Trial in Prior Litigation Involving the ’112 Patent Commences
2020-05-04 D. Del. Upholds Validity of Claim 31 of ’112 Patent
2021-03-08 Federal Circuit Affirms Prior Validity Decision
2025-05-19 FDA Grants Pediatric Exclusivity for KYPROLIS®
2025-07-21 Defendant Sends Notice Letter Regarding Generic NDA Filing
2025-09-04 Complaint Filed

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

U.S. Patent No. 7,737,112 - Composition For Enzyme Inhibition

The Invention Explained

  • Problem Addressed: The patent addresses the technical challenge that certain potent proteasome inhibitors, specifically peptide epoxy ketones, have low aqueous solubility, which "makes it difficult to formulate compositions with optimal bioavailability" for administration to patients (’112 Patent, col. 1:23-26).
  • The Patented Solution: The invention solves this solubility problem by creating a pharmaceutical composition that combines the "practically insoluble proteasome inhibitor" with a cyclodextrin, which is a type of solubilizing excipient, and optionally a buffer to control pH (’112 Patent, col. 1:35-39, col. 2:31-32). The specification explains that this formulation significantly enhances the solubility of the active drug, facilitating its administration as a therapeutic product (’112 Patent, Abstract). Figures 1 and 2 of the patent illustrate how solubility and chemical stability are dependent on pH in such formulations (’112 Patent, Figs. 1-2).
  • Technical Importance: This formulation technology enables the delivery of a class of otherwise difficult-to-administer therapeutic compounds, allowing potent but poorly soluble drugs to be developed into commercially viable and effective injectable treatments for serious diseases (’112 Patent, col. 1:14-18).

Key Claims at a Glance

  • The complaint asserts independent claims 1 and 31, among others (Compl. ¶40).
  • Independent Claim 1 requires:
    • A pharmaceutical composition comprising a "practically insoluble peptide epoxy ketone proteasome inhibitor" or its salt.
    • A "substituted cyclodextrin selected from hydroxypropyl beta-cyclodextrin and sulfobutyl ether beta-cyclodextrin (SBECD)."
  • Independent Claim 31 requires:
    • A pharmaceutical composition comprising a compound with the specific chemical structure of carfilzomib or its salt.
    • The composition is "in an aqueous solution containing 10% (w/v) SBECD and 10 mM citric acid adjusted to pH 3.5."
  • The complaint asserts infringement of claims 1-9, 14, 18-24, and 29-31, thereby including dependent claims (Compl. ¶40).

III. The Accused Instrumentality

Product Identification

  • The accused instrumentality is Defendant's "Proposed 505(b)(2) Product," an application for a generic version of Plaintiff’s KYPROLIS® (carfilzomib) for injection (Compl. ¶¶6, 8).

Functionality and Market Context

  • The proposed product is a proteasome inhibitor intended for intravenous use to treat relapsed or refractory multiple myeloma (Compl. ¶34). The complaint alleges that Defendant’s New Drug Application (NDA) contains data demonstrating the bioequivalence of its proposed generic product to KYPROLIS® (Compl. ¶35). The infringement action was triggered by Defendant filing its NDA with a "Paragraph IV Certification," asserting that the ’112 Patent is invalid or will not be infringed by its proposed product (Compl. ¶26). Such a filing is defined as an act of infringement under 35 U.S.C. § 271(e)(2) to allow for resolution of patent disputes prior to the launch of the generic drug. No probative visual evidence provided in complaint.

IV. Analysis of Infringement Allegations

The complaint alleges that Defendant's proposed product will infringe the ’112 Patent upon commercial manufacture, use, or sale (Compl. ¶43). The infringement theory is based on the allegation that the proposed generic product is bioequivalent to KYPROLIS® and that its formulation will necessarily fall within the scope of the asserted claims (Compl. ¶¶35, 40).

’112 Patent Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
A pharmaceutical composition comprising a practically insoluble peptide epoxy ketone proteasome inhibitor... Defendant’s product contains carfilzomib, which is alleged to be a peptide epoxy ketone proteasome inhibitor. ¶34 col. 1:19-22
...and a substituted cyclodextrin selected from... sulfobutyl ether beta-cyclodextrin (SBECD). The composition of Plaintiff's KYPROLIS® includes SBECD, and Defendant's proposed generic is alleged to be bioequivalent and to have a substantially similar composition. ¶¶18, 35 col. 3:7-10
  • Identified Points of Contention:
    • Factual Question: The central dispute will likely be factual: what is the precise formulation of Defendant's proposed generic product? The complaint's allegations are based on "information and belief" that the generic formulation will mirror the brand-name KYPROLIS® formulation (Compl. ¶35). The defense will likely depend on demonstrating that its formulation uses different components, concentrations, or parameters that place it outside the scope of the asserted claims.
    • Scope Question: A potential, though less likely, point of contention could be the construction of "practically insoluble." The defense could argue that its manufacturing process or specific formulation renders the active ingredient soluble in a manner not contemplated by the patent, thereby avoiding this claim limitation.

V. Key Claim Terms for Construction

  • The Term: "practically insoluble"
  • Context and Importance: This term defines the universe of active pharmaceutical ingredients to which the claimed formulation technology applies. The infringement analysis depends on whether the active ingredient in the accused product, carfilzomib, meets this definition within the context of the patent. Practitioners may focus on this term to determine if there is a non-infringement argument based on the properties of Defendant's specific drug substance or formulation process.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The specification provides a quantitative definition, stating that "practically insoluble" refers to inhibitors that "generally have a solubility of less than 0.1 mg/mL in water" (’112 Patent, col. 33:34-36). This could be argued to apply broadly, irrespective of the specific manufacturing process.
    • Evidence for a Narrower Interpretation: A party could argue the term should be understood in the context of the specific problem the patent solves, namely the difficulty of formulating specific peptide epoxy ketones like "peptide (a)" (carfilzomib) mentioned in the background (’112 Patent, col. 1:19-26).

VI. Other Allegations

  • Indirect Infringement: The complaint alleges induced infringement, stating that Defendant’s proposed product label will instruct healthcare providers to reconstitute and administer the drug in a manner that directly infringes the patent's claims (Compl. ¶36). Contributory infringement is also alleged based on the assertion that the product will have no substantial non-infringing uses (Compl. ¶38).
  • Willful Infringement: The complaint alleges that Defendant had knowledge of the ’112 Patent at the time it filed its NDA, satisfying a prerequisite for willfulness (Compl. ¶¶28, 45). It further alleges that Defendant "is knowingly and intentionally infringing" the patent (Compl. ¶46).

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

  • A core issue will be one of factual correspondence: Does the final formulation of Amneal’s proposed generic product, once disclosed, contain sulfobutyl ether beta-cyclodextrin (SBECD) as the solubilizing agent, and do its concentration, pH, and other parameters fall within the specific limitations of asserted claims such as Claim 31?
  • A key legal and evidentiary question will be one of infringement by equivalence: If Amneal’s product does not literally infringe (e.g., by using a chemically similar but different cyclodextrin), does its formulation contain elements that are equivalent to the claimed "substituted cyclodextrin" under the doctrine of equivalents?
  • The case will also present a question of remedy: Given the prior Federal Circuit decision affirming the validity of Claim 31, if infringement is found, the court will need to determine the effective date of any FDA approval for Amneal's generic, which Plaintiff requests be no earlier than the expiration of the ’112 Patent (Compl. p. 12).