DCT

1:25-cv-01156

Advanced Accelerator Applications USA Inc v. Curium US LLC

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Amended Complaint
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I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 1:25-cv-01156, D. Del., 07/23/2026
  • Venue Allegations: Venue is alleged based on Defendant entities being organized under the laws of Delaware or being foreign corporations subject to suit in any judicial district.
  • Core Dispute: Plaintiff alleges that Defendants' filing of a New Drug Application with the FDA for a generic version of Plaintiff's radiopharmaceutical product LUTATHERA® constitutes an act of infringement of a patent covering stable, concentrated drug formulations.
  • Technical Context: The lawsuit concerns radioligand therapy, a cancer treatment that uses radioactive molecules to target and destroy tumor cells, and specifically involves formulations designed to improve the stability and shelf-life of these drugs.
  • Key Procedural History: This is a Hatch-Waxman Act case triggered by Defendants' (collectively "Curium") filing of New Drug Application (NDA) No. 218525. Curium sent a series of notice letters to Plaintiff, including one on April 6, 2026, containing a Paragraph IV certification asserting that U.S. Patent No. 12,415,003 is invalid, unenforceable, and/or will not be infringed by Curium's proposed product. Under U.S. patent law, this filing is a technical act of infringement that allows the patent holder to sue before the accused product enters the market.

Case Timeline

Date Event
2018-07-25 Priority Date for U.S. Patent No. 12,415,003
2024-09-05 Curium sends first Paragraph IV notice letter to Plaintiff
2025-02-07 Curium sends second Paragraph IV notice letter to Plaintiff
2025-09-16 U.S. Patent No. 12,415,003 Issues
2026-04-06 Curium sends Paragraph IV notice letter regarding the '003 patent
2026-07-23 First Amended Complaint Filed

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

U.S. Patent No. 12,415,003 - "Stable, Concentrated Radionuclide Complex Solutions"

  • Patent Identification: U.S. Patent No. 12,415,003 ("the '003 patent"), titled "Stable, Concentrated Radionuclide Complex Solutions", issued on September 16, 2025 Compl. ¶28 '003 Patent, front page

The Invention Explained

  • Problem Addressed: The patent addresses the inherent instability of radiopharmaceutical drugs '003 Patent, col. 1:52-60 The energy released by radioactive decay degrades the drug molecules through a process called radiolysis, reducing efficacy and shelf-life '003 Patent, col. 1:52-60 This problem historically required such drugs to be prepared in small batches at a hospital immediately before administration, which is inefficient and limits access '003 Patent, col. 2:1-21 Creating a highly concentrated solution, which is desirable for patient convenience, exacerbates the radiolysis problem '003 Patent, col. 2:37-49
  • The Patented Solution: The invention is a stable, concentrated, and "ready-to-use" radiopharmaceutical solution that uses stabilizers to counteract radiolytic degradation '003 Patent, abstract The patent describes that "sufficient stability may be achieved already with one single stabilizer," but found that "the use of two stabilizers has been found to be of particular suitability" '003 Patent, col. 4:12-15 This dual-stabilizer approach involves adding one stabilizer during the initial complex formation reaction and a second stabilizer after the reaction is complete, which is said to enhance protection and improve the product's shelf-life '003 Patent, col. 4:15-31
  • Technical Importance: This technology enables the centralized, commercial-scale manufacturing of a radiopharmaceutical product that remains stable long enough to be shipped to clinical centers, thereby obviating the need for on-site, just-in-time preparation and increasing the drug's availability '003 Patent, col. 4:46-64

Key Claims at a Glance

The complaint alleges infringement of "one or more claims" of the '003 patent without specifying them Compl. ¶41 Independent claim 23, a composition claim, is representative of the core invention.

  • Independent Claim 23: A pharmaceutical aqueous solution comprising:
    • (a) a complex formed by (ai) the radionuclide ¹⁷⁷Lutetium (Lu-177), present in a concentration that it provides a volumetric radioactivity of from 250 to 500 MBq/mL, and (aii) the chelating agent linked somatostatin receptor binging organic moiety DOTA-TATE (oxodotreotide) or DOTA-TOC (edotreotide);
    • (bi) gentisic acid or a salt thereof as the first stabilizer against radiolytic degradation present in a concentration of from 0.5 to 1 mg/ml;
    • (bii) ascorbic acid or a salt thereof as the second stabilizer against radiolytic degradation present in a concentration of from 2.0 to 5.0 mg/mL.
  • The complaint reserves the right to assert other claims, which may include dependent claims or other independent claims covering processes of manufacturing and methods of treatment Compl. ¶41

III. The Accused Instrumentality

Product Identification

  • The accused instrumentality is Defendants' proposed "Lutetium Lu-177 Dotatate injection solution," for which they seek FDA approval via New Drug Application (NDA) No. 218525 Compl. ¶12 It is described as a "version of ADACAP's LUTATHERA®" and is referred to as "Curium's 505(b)(2) Product" Compl. ¶1 Compl. ¶12

Functionality and Market Context

  • The complaint does not describe the specific formulation of the accused product. Instead, it alleges that by filing a 505(b)(2) application, Defendants have represented to the FDA that their product will have the same active ingredient (lutetium Lu 177 dotatate), method of administration, dosage form, and strength as Plaintiff's LUTATHERA® product, and will be bioequivalent to it Compl. ¶39
  • LUTATHERA® is a marketed treatment for somatostatin receptor-positive gastroenteropancreatic neuroendocrine tumors (GEP-NETs) Compl. ¶30 The complaint alleges that Curium intends to commercially manufacture, market, and sell its competing product in the United States immediately upon FDA approval Compl. ¶43

No probative visual evidence provided in complaint.

IV. Analysis of Infringement Allegations

The complaint does not provide a detailed, element-by-element infringement analysis or an accompanying claim chart. The infringement allegation is a statutory one under the Hatch-Waxman Act, 35 U.S.C. § 271(e)(2)(A), which defines the submission of an NDA for a drug claimed in a patent as an act of infringement Compl. ¶41

The narrative theory of infringement is that Defendants' 505(b)(2) product will necessarily infringe the '003 patent upon approval Compl. ¶41 This is based on the allegation that Plaintiff's own product, LUTATHERA®, is covered by the claims of the '003 patent Compl. ¶31 Compl. ¶38 and that Defendants have represented to the FDA that their proposed product will have the same active ingredient, strength, and dosage form as LUTATHERA®, and be bioequivalent to it Compl. ¶39 The complaint thus posits that the properties of the accused product, once manufactured, will fall within the scope of the '003 patent's claims.

  • Identified Points of Contention:
    • Technical Questions: A primary question for the court will be whether Defendants' product formulation, once revealed in discovery, meets all limitations of the asserted claims. The analysis will likely focus on the stabilizers used. Does the accused product contain the specific combination of gentisic acid and ascorbic acid as claimed, and are they present within the claimed concentration ranges? A non-infringement defense may arise if Defendants have "designed around" the patent by using different stabilizers, different concentrations, or a different number of stabilizers.
    • Scope Questions: The infringement analysis may also turn on how the court construes key claim terms. For example, if Defendants' product uses stabilizers other than gentisic and ascorbic acid, the case could depend on whether the term "stabilizer against radiolytic degradation" is interpreted broadly to cover those alternatives or is limited to the examples disclosed in the '003 patent.

V. Key Claim Terms for Construction

The complaint does not identify any specific claim terms for construction. However, based on the technology and the likely areas of dispute, the following terms may be critical.

  • The Term: "stabilizer against radiolytic degradation"

  • Context and Importance: This term is central to the invention's novelty. The identity and quantity of stabilizers will be a key factual issue. Practitioners may focus on this term because Defendants will likely argue that their chosen formulation, if different from the patent's examples, does not use a "stabilizer" as that term should be properly construed, or that the term should be limited to the specific embodiments described.

  • Intrinsic Evidence for Interpretation:

    • Evidence for a Broader Interpretation: The specification provides a list of potential stabilizers, stating they "may be selected from gentisic acid... ascorbic acid... methionine, histidine, melatonin, ethanol, and Se-methionine" '003 Patent, col. 5:19-23 Plaintiffs may argue this list supports a construction that is not limited to only the gentisic/ascorbic acid combination.
    • Evidence for a Narrower Interpretation: The abstract and summary repeatedly highlight the "particular advantage" and "particular suitability" of using a specific sequence of two different stabilizers '003 Patent, abstract '003 Patent, col. 4:12-31 Defendants may argue that this focus on a specific combination and process implies a narrower scope for the claimed invention.

  • The Term: "a concentration that it provides a volumetric radioactivity of from 250 to 500 MBq/mL"

  • Context and Importance: This numerical range defines the "concentrated" nature of the claimed solution. Infringement requires the accused product to fall within this precise range.

  • Intrinsic Evidence for Interpretation:

    • Evidence for a Broader Interpretation: The specification mentions a broader range of "from 100 to 1000 MBq/mL" in one embodiment, which a party could potentially use to contextualize the claimed range, although this is generally a weak argument against an explicit numerical limitation in a claim '003 Patent, col. 5:53-55
    • Evidence for a Narrower Interpretation: Claim 23 recites the explicit range "from 250 to 500 MBq/mL" '003 Patent, col. 8:44-45 Courts typically interpret such numerical ranges as definitive limitations. A party arguing for a narrow construction would assert that any product with a concentration outside this exact range does not infringe.

VI. Other Allegations

  • Indirect Infringement: The complaint pleads both induced and contributory infringement Compl. ¶48 Compl. ¶57 Inducement is alleged based on Defendants' intent to market their product with labeling that will instruct users to infringe Compl. ¶43 Compl. ¶46 Contributory infringement is suggested by the allegation that Defendants' product is "especially made or adapted for use in infringing the '5003 patent" and is "not suitable for any substantial non-infringing use" Compl. ¶47 Compl. ¶56
  • Willful Infringement: The complaint does not use the word "willful" but alleges Defendants have had "actual and constructive knowledge of the '5003 patent" since at least September 10, 2025 (a clerical error, as the patent issued on September 16, 2025) and know that their product "would infringe" Compl. ¶42 Compl. ¶45 The allegation of knowledge is based on Defendants' April 6, 2026 Paragraph IV notice letter, which post-dates the patent's issuance and could form the basis for a future willfulness claim Compl. ¶¶16-17

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

This case appears to be a classic Hatch-Waxman dispute where the outcome will depend on facts revealed during discovery concerning the precise nature of the accused generic product. The central questions for the court will likely be:

  1. A core issue will be one of technical identity: Does the specific formulation of Curium's proposed product-particularly its choice and concentration of stabilizers-fall within the literal scope of the asserted claims of the '003 patent? The case will likely turn on a comparison between the claims' requirements and the undisclosed details of Curium's drug formulation.

  2. A key legal question will be one of claim construction: If Curium's product uses a different formulation, can Plaintiff convince the court to adopt a construction of terms like "stabilizer" that is broad enough to read on Curium's approach, or will the court limit the claims to the specific embodiments detailed in the patent, potentially allowing Curium's "design around" to succeed?

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