DCT

1:25-cv-00446

Intrabio Inc v. Tesseract Medical Research LLC

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Key Events
Amended Complaint

I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 1:25-cv-00446, D. Del., 05/23/2025
  • Venue Allegations: Venue is alleged to be proper in the District of Delaware because Defendants are organized and existing under the laws of Delaware, have regular and systematic contacts in the district, and have allegedly committed acts of infringement there.
  • Core Dispute: Plaintiff alleges that Defendant’s N-acetyl-L-leucine dietary supplement infringes patents related to methods of using acetyl-leucine to treat various neurodegenerative diseases, migraines, and other conditions.
  • Technical Context: The technology involves the use of N-acetyl-L-leucine (NALL), an amino acid derivative, as a therapeutic agent for a range of neurological disorders.
  • Key Procedural History: The complaint states that Plaintiff sent Defendant a cease-and-desist letter notifying it of the alleged infringement. Additionally, the complaint notes that U.S. Patent No. 11,400,067 was the subject of a supplemental reexamination request, and the USPTO has issued an intent to issue a reexamination certificate.

Case Timeline

Date Event
2016-08-11 Earliest Priority Date for ’067 Patent and ’792 Patent
2017-06-14 Earliest Priority Date for ’434 Patent
2018-02-15 Earliest Priority Date for ’279 Patent
2022-08-02 ’067 Patent Issued
2022-10-18 ’434 Patent Issued
2023-05-30 ’279 Patent Issued
2024-09-24 FDA approves Plaintiff's drug AQNEURSA (NALL)
2024-10-09 Plaintiff requests supplemental reexamination of the ’067 Patent
2024-11-19 ’792 Patent Issued
2025-03-26 Date of Defendant's marketing email cited in complaint
2025-03-31 USPTO issues intent to issue reexamination certificate for '067 Patent
2025-04-08 Plaintiff sends cease-and-desist letter to Defendant
2025-05-23 Complaint Filed

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

U.S. Patent No. 11,400,067, "Pharmaceutical compositions and uses directed to lysosomal storage disorders," issued August 2, 2022

The Invention Explained

  • Problem Addressed: The patent describes lysosomal storage disorders (LSDs) as a group of over 70 inherited metabolic diseases with limited therapeutic options, particularly a lack of general, non-specific treatments that can benefit a wide range of LSDs (ʼ067 Patent, col. 1:20-22, 1:40-52).
  • The Patented Solution: The invention is a method of treating LSDs by administering acetyl-leucine. The disclosure is based on the discovery that acetyl-leucine can improve both the cellular dysfunction underlying these disorders (e.g., by reducing enlarged lysosomal volume) and the resulting clinical abnormalities (ʼ067 Patent, Abstract; col. 5:15-21).
  • Technical Importance: This approach provides a potential therapeutic agent for a broad class of severe, progressive, and often fatal neurodegenerative diseases for which curative treatments are largely unavailable (ʼ067 Patent, col. 1:33-38, 1:40-43).

Key Claims at a Glance

  • The complaint asserts at least claim 14 (Compl. ¶58). Claim 14 depends from independent claim 1.
  • Essential elements of independent claim 1 include:
    • A method of treating a lysosomal storage disorder (LSD) or associated symptoms in a subject.
    • The method comprises administering a therapeutically effective amount of acetyl-leucine or a salt thereof.
    • The LSD is selected from a specific list including Niemann-Pick type C disease, Tay-Sachs disease, and others.
  • Dependent claim 14 adds the limitation that the acetyl-leucine is in the single enantiomeric form of the L-enantiomer.

U.S. Patent No. 11,471,434, "Treatment for migraine," issued October 18, 2022

The Invention Explained

  • Problem Addressed: The patent identifies a need for alternative treatments for migraines, which affect a significant portion of the population, and highlights a specific lack of drugs for the prophylactic treatment of migraine auras (ʼ434 Patent, col. 1:11-12, col. 4:1-8).
  • The Patented Solution: The invention proposes a method of treating or preventing migraines and their associated symptoms by administering leucine or acetyl-leucine. The patent presents this as a surprising new application for these compounds (ʼ434 Patent, Abstract; col. 4:62-67).
  • Technical Importance: The invention offers a novel therapeutic approach for a prevalent and debilitating condition where existing treatments can have significant drawbacks or limited efficacy (ʼ434 Patent, col. 3:62-67).

Key Claims at a Glance

  • The complaint asserts at least claim 19 (Compl. ¶58). Claim 19 depends from independent claim 1.
  • Essential elements of independent claim 1 include:
    • A method of treating or preventing a migraine or its associated symptoms.
    • The method consists of administering a therapeutically or prophylactically effective amount of acetyl-leucine or a salt thereof.
    • A negative limitation: "wherein the migraine is not associated with vertigo or symptoms of vertigo."
  • Dependent claim 19 further specifies that the therapeutically effective amount is from about 500 mg to about 15 g per day.

U.S. Patent No. 11,660,279, “Therapeutic agents for treating restless leg syndrome,” issued May 30, 2023

  • Technology Synopsis: The patent addresses the need for more effective treatments for Restless Leg Syndrome (RLS) that avoid the undesirable side effects of existing drug therapies (ʼ279 Patent, col. 2:28-31). The patented solution is a method of treating RLS by administering leucine or acetyl-leucine (ʼ279 Patent, Abstract).
  • Asserted Claims: The complaint asserts at least claim 13 (Compl. ¶58), which depends from independent claim 12, which in turn depends from independent claim 1.
  • Accused Features: The complaint alleges infringement through Defendants' promotion of their NALL product for general neurological health benefits, which Plaintiffs contend induces the treatment of conditions including RLS (Compl. ¶47-48).

U.S. Patent No. 12,144,792, “Therapeutic agents for neurodegenerative diseases,” issued November 19, 2024

  • Technology Synopsis: The patent describes a need for improved and broadly applicable treatments for neurodegenerative diseases, many of which are severe, progressive, and lack curative options (ʼ792 Patent, col. 1:19-21). The invention provides a method of treating such diseases, including Alzheimer's and Parkinson's, by administering acetyl-leucine (ʼ792 Patent, Abstract).
  • Asserted Claims: The complaint asserts at least claim 18 (Compl. ¶58), which depends from independent claim 1.
  • Accused Features: The complaint points to Defendants' marketing of its NALL product for "neuroprotection," optimizing "neurological health and longevity," and potential in "various therapeutic areas," which Plaintiffs allege constitutes inducement to treat neurodegenerative diseases (Compl. ¶48, ¶85h).

III. The Accused Instrumentality

  • Product Identification: The accused instrumentality is Defendants' product marketed as “N-Acetyl-L-Leucine™,” also referred to as NALL (Compl. ¶47-49).
  • Functionality and Market Context: The product is a dietary supplement containing N-acetyl-L-leucine (Compl. ¶47). Defendants' website, as depicted in the complaint, describes the product as "powerful support for brain health, cognitive function, and promotes [sic] healthy aging" and notes that it "provides only the L-isomer for superior efficacy and bioavailability" (Compl. ¶48, ¶49). A screenshot from the product webpage shows it being offered for sale. (Compl. ¶49, p. 14). The complaint alleges that this product is an "unapproved new drug" being unlawfully marketed as a supplement to evade FDA regulations and that it is promoted as a substitute for Plaintiff's FDA-approved NALL-based drug, AQNEURSA (Compl. ¶6, ¶19, ¶53).

IV. Analysis of Infringement Allegations

’067 Patent Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
A method of treating a lysosomal storage disorder (LSD) ... wherein the LSD is chosen from Niemann-Pick type C disease... Defendants allegedly induce treatment of LSDs by marketing their NALL product with express references to Plaintiffs’ clinical study on N-acetyl-L-leucine for Niemann-Pick disease type C, and by claiming the "efficacy and safety of NALL have been investigated for several lysosomal disorders." ¶52, ¶85(b), (c) col. 33:1-11
in a subject in need thereof comprising: administering a therapeutically effective amount of acetyl-leucine, or a pharmaceutically acceptable salt thereof... Defendants provide "Suggested Use" instructions on their website, such as "Take 2 capsules two times daily," which allegedly encourages customers to administer the N-acetyl-L-leucine product. An excerpt from a marketing email similarly recommends users to "Prescribe N-Acetyl-L-Leucine (NALL)." ¶50, ¶51 col. 13:41-43
Element from Dependent Claim 14: wherein the acetyl-leucine is in a single enantiomeric form of either the L-enantiomer or the D-enantiomer, and wherein the single enantiomeric form is the L-enantiomer. The accused product is explicitly marketed as "N-Acetyl-L-Leucine™." A screenshot of the product website states that "NALL provides only the L-isomer for superior efficacy and bioavailability," directly corresponding to the L-enantiomer limitation. ¶49 col. 33:13-14
  • Identified Points of Contention:
    • Scope Questions: A central question may be whether marketing a product as a "dietary supplement" for "neurological health" and "longevity" (Compl. ¶48) constitutes inducement to perform a patented method of "treating" a specific, diagnosed medical disease like an LSD.
    • Technical Questions: The infringement analysis may focus on the extent to which Defendants' marketing materials, including references to Plaintiff's own clinical research for Niemann-Pick disease type C (Compl. ¶52, ¶85(c)), create a direct link between the accused supplement and the claimed method of treatment.

’434 Patent Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
A method of treating or preventing a migraine, or one or more symptoms associated therewith, in a subject... Defendants allegedly market their NALL product with claims that it "provide[s] protection against other more common neurological symptoms and migraines." ¶85(g) col. 1:8-10
said method consisting of administering to the subject a therapeutically or prophylactically effective amount of acetyl-leucine, or a pharmaceutically acceptable salt thereof... Defendants provide "Suggested Use" instructions for their N-acetyl-L-leucine product, such as "Take 2 capsules two times daily," which allegedly encourages customers to perform the administration step. ¶50 col. 7:60-66
wherein the migraine is not associated with vertigo or symptoms of vertigo. The complaint's allegations regarding migraine treatment do not specify whether the induced method is limited to migraines without vertigo. Infringement of this negative limitation may depend on evidence showing the scope of the induced use. ¶85(g) col. 6:33-37
Element from Dependent Claim 19: wherein the therapeutically or prophylactically effective amount is from about 500 mg to about 15 g per day. The complaint does not provide sufficient detail for analysis of this element, as the dosage amount per capsule of the accused product is not specified. ¶50 col. 9:22-25
  • Identified Points of Contention:
    • Scope Questions: A key issue may be whether Defendants' general marketing statement about "migraines" (Compl. ¶85(g)) is sufficient to induce infringement of a claim that is narrowly tailored to treat only those migraines not associated with vertigo.
    • Technical Questions: What evidence does the complaint provide that the dosage suggested by Defendants ("Take 2 capsules two times daily") falls within the range required by asserted claim 19? The complaint does not specify the amount of NALL per capsule.

V. Key Claim Terms for Construction

  • The Term: "treating"

    • Context and Importance: This term is central to the dispute, as Defendants market their product as a "dietary supplement" for general health "support," while the patents claim methods of "treating" specific diseases. Practitioners may focus on this term because its construction could determine whether promoting a supplement for wellness constitutes inducement to practice a patented medical treatment method.
    • Intrinsic Evidence for Interpretation:
      • Evidence for a Broader Interpretation: The '067 patent specification defines "treating" broadly to include "delaying onset," "reducing the severity," "delaying progression," and "reversing progression" of a disease or its symptoms, which could encompass prophylactic or symptom-management uses (ʼ067 Patent, col. 8:56-65).
      • Evidence for a Narrower Interpretation: The patent's examples detail clinical case studies of patients with diagnosed diseases (e.g., Tay-Sachs, GM1 Gangliosidosis) receiving acetyl-leucine under medical supervision, which may suggest that "treating" implies a formal medical intervention for a diagnosed condition (ʼ067 Patent, col. 25:19–col. 28:56).

  • The Term: "therapeutically effective amount"

    • Context and Importance: The definition of this term is critical for determining what dosage constitutes an infringing act. An amount effective for general "neurological health" may be argued to be different from a "therapeutically effective amount" for a specific, severe disease like an LSD.
    • Intrinsic Evidence for Interpretation:
      • Evidence for a Broader Interpretation: The specification defines the term as "any amount which, when administered to a subject, is the amount of agent that is needed to produce the desired effect," which could be interpreted broadly to include any beneficial outcome (ʼ067 Patent, col. 19:28-31).
      • Evidence for a Narrower Interpretation: The specification provides specific, high-dosage ranges for administration, such as "from about 1.5 g to about 10 g per day," often based on clinical data, suggesting the term may be construed to require a substantial, clinically relevant dosage (ʼ067 Patent, col. 13:41-43).

VI. Other Allegations

  • Indirect Infringement: The complaint alleges active inducement of infringement, citing Defendants' activities of "selling, marketing, advertising, promotion," and providing instructions for use on their website and in marketing emails (Compl. ¶59). A marketing email is cited which encourages recipients to "Prescribe Tesseract's NEW N-acetyl-L-leucine" (Compl. ¶51). The complaint also alleges contributory infringement, stating that NALL is not a staple article of commerce suitable for substantial non-infringing uses (Compl. ¶60).
  • Willful Infringement: Willfulness is alleged based on pre-suit knowledge via a cease-and-desist letter sent to Defendant Tesseract Medical Research, LLC on April 8, 2025 (Compl. ¶35), and on Defendants' alleged continuation of infringing activities after receiving notice of the Asserted Patents (Compl. ¶62).

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

  • A core issue will be one of definitional scope: can the term "treating," as used in the context of patented medical methods, be construed to cover the activities induced by the marketing of a "dietary supplement" for general "neurological health" and "longevity"? The outcome may depend on how directly Defendants' marketing links their product to the specific diseases claimed in the patents.
  • A key evidentiary question will be one of induced use: does the evidence, such as Defendants' alleged citation of Plaintiff's clinical study for Niemann-Pick disease type C, establish that Defendants specifically intended for consumers to use their product to perform the patented methods, as opposed to for general wellness?
  • A central legal question for the '434 patent will be one of negative limitations: can Plaintiff demonstrate that Defendants induced infringement of a claim that specifically excludes migraines associated with vertigo, when the allegedly inducing marketing materials refer to "migraines" generally?