DCT

2:26-cv-08481

Ultragenyx Pharmaceutical Inc v. Sun Pharmaceutical Industries Ltd

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I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 2:26-cv-08481, D.N.J., 07/09/2026
  • Venue Allegations: Venue is alleged to be proper for the foreign defendant (Sun Ltd.) as it is subject to personal jurisdiction in the district. For the domestic defendant (Sun Inc.), venue is based on its alleged regular and established place of business in the District of New Jersey and the commission of acts of infringement there.
  • Core Dispute: Plaintiffs allege that Defendants' filing of an Abbreviated New Drug Application (ANDA) to market a generic version of Plaintiffs' Dojolvi® (triheptanoin) product constitutes an act of infringement of two U.S. patents.
  • Technical Context: The technology relates to pharmaceutical compositions of triheptanoin for treating rare genetic diseases, specifically long-chain fatty acid oxidation disorders (LC-FAOD), which impair the body's ability to convert long-chain fats into energy.
  • Key Procedural History: This action was initiated under the Hatch-Waxman Act following Plaintiffs' receipt of a Paragraph IV certification notice letter from Defendants, indicating their intent to market a generic product prior to the expiration of the patents-in-suit. The complaint states it was filed within 45 days of receiving this notice, which would trigger an automatic 30-month stay on FDA approval of the Defendants' ANDA. The complaint also notes related, pending litigation against another generic manufacturer, Navinta LLC, concerning the same drug product.

Case Timeline

Date Event
2004-07-02 '748 Patent Priority Date
2013-11-14 '461 Patent Priority Date
2014-04-15 '748 Patent Issue Date
2026-02-17 '461 Patent Issue Date
2026-05-26 Defendant Sun sends Paragraph IV Notice Letter to Plaintiffs
2026-07-09 Complaint Filing Date

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

U.S. Patent No. 8,697,748

  • Patent Identification: U.S. Patent No. 8,697,748, "Glycogen or polysaccharide storage disease treatment method," issued April 15, 2014. Compl. ¶7
  • The Invention Explained:
    • Problem Addressed: The patent addresses genetic glycogen storage diseases (GSDs), like Pompe's disease, where enzyme deficiencies lead to the abnormal accumulation of glycogen. This accumulation causes cellular damage, progressive muscle weakness, and organ dysfunction, potentially leading to respiratory failure and death. Compl., Ex. A, '748 Patent, col. 1:26-34 '748 Patent, col. 1:50-54
    • The Patented Solution: The invention proposes administering odd-carbon fatty acids, such as triheptanoin (a triglyceride of heptanoic acid, a C7 fatty acid), as an alternative energy source. '748 Patent, abstract This therapy, termed anaplerosis, aims to bypass the defective metabolic pathways by providing substrates (acetyl-CoA and propionyl-CoA) that directly replenish the citric acid cycle (CAC), the central engine of cellular energy production. This reduces the body's reliance on breaking down stored glycogen or muscle protein for energy. '748 Patent, col. 19:10-21 '748 Patent, FIG. 4
    • Technical Importance: This approach provided a novel metabolic therapy for diseases where treatment options were limited, aiming to supply energy directly to the cell's mitochondria and thereby ameliorate the underlying energy deficit. '748 Patent, col. 2:47-53
  • Key Claims at a Glance:
    • The complaint asserts at least independent claim 1. Compl. ¶49
    • Independent Claim 1 requires:
      • A composition comprising an active agent, wherein the active agent consists essentially of a triheptanoin
      • the composition has an acid value of 0.1 or less mg KOH/gr
      • the composition has a hydroxyl value of 2.8 or less mg KOH/gr
    • The complaint alleges infringement of "one or more claims," reserving the right to assert others. Compl. ¶49

U.S. Patent No. 12,551,461

  • Patent Identification: U.S. Patent No. 12,551,461, "Compositions of triglycerides and uses thereof," issued February 17, 2026. Compl. ¶10
  • The Invention Explained:
    • Problem Addressed: The patent describes problems associated with prior art liquid oil formulations of triglycerides like triheptanoin. These problems include poor miscibility with food and drinks, handling difficulties, and significant gastrointestinal side effects like gastric upset, vomiting, and diarrhea, which can limit the tolerable and effective dose. '461 Patent, col. 1:26-44
    • The Patented Solution: The patent primarily describes a solid composition where the triglyceride oil is adsorbed onto a solid substance, such as fumed silica, to create a powder or granule. '461 Patent, abstract This solid formulation is intended to be more stable, easier to handle, and provide a delayed or sustained release profile to improve gastrointestinal tolerability and patient compliance. '461 Patent, col. 7:16-50
    • Technical Importance: This technology aims to create a more patient-friendly and tolerable dosage form for triglyceride-based therapies, which could enable better clinical outcomes by allowing for higher dosing and improved adherence. '461 Patent, col. 8:1-5
  • Key Claims at a Glance:
    • The complaint asserts at least independent claim 1. Compl. ¶58
    • Independent Claim 1 requires:
      • A pharmaceutical composition comprising an active ingredient, diheptanoate, and hexano-diheptanoate, wherein the active ingredient is in the form of triheptanoin oil
      • wherein the triheptanoin oil has a purity greater than 98%
      • wherein the composition comprises 0.01% to 1.5% diheptanoate by weight
      • wherein the composition comprises 0.01% to 1.0% hexano-diheptanoate by weight
      • wherein glycerol is undetectable in the composition
      • wherein monoheptanoate is undetectable in the composition
      • wherein the composition comprises no more than 0.2% water by weight
      • and wherein the composition is a liquid composition for oral administration to a human
    • The complaint alleges infringement of "one or more claims," reserving the right to assert others. Compl. ¶58

III. The Accused Instrumentality

  • Product Identification: The accused instrumentality is Defendants' "Sun's ANDA Product," identified as a proposed generic version of Dojolvi® (triheptanoin) Oral Liquid, 100% w/w, submitted to the FDA under ANDA No. 219341. Compl. ¶1
  • Functionality and Market Context:
    • The complaint alleges that Sun's ANDA Product is a triheptanoin oral liquid. Compl. ¶40
    • The product is intended for the same therapeutic use as Plaintiffs' Dojolvi® product: the treatment of adult and pediatric patients with molecularly confirmed long-chain fatty acid oxidation disorders (LC-FAOD). Compl. ¶13 Compl. ¶39
    • Sun has represented to the FDA that its product is "bioequivalent" to Plaintiffs' Dojolvi®. Compl. ¶41 The act of infringement alleged is the filing of the ANDA itself, seeking to market this product before the expiration of the patents-in-suit. Compl. ¶1 Compl. ¶47 Compl. ¶56

IV. Analysis of Infringement Allegations

No probative visual evidence provided in complaint.

U.S. Patent No. 8,697,748 Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
A composition comprising an active agent, wherein the active agent consists essentially of a triheptanoin, Defendants' ANDA Product is a "triheptanoin oral liquid." ¶40 col. 2:65-67
and wherein the composition has an acid value of 0.1 or less mg KOH/gr, The complaint alleges that to be an approvable generic, Defendants' ANDA Product will necessarily meet the purity specifications of the branded drug, which is covered by the patent. ¶41; ¶47 claim 1
a hydroxyl value of 2.8 or less mg KOH/gr. The complaint alleges that to be an approvable generic, Defendants' ANDA Product will necessarily meet the purity specifications of the branded drug, which is covered by the patent. ¶41; ¶47 claim 1
  • Identified Points of Contention:
    • Scope Questions: The infringement analysis may turn on the construction of the term "consists essentially of." A court will need to determine if any excipients or other components in the accused product materially alter the basic and novel properties of the claimed triheptanoin composition.
    • Technical Questions: A central evidentiary question will be whether the product specifications submitted in Sun's ANDA actually meet the claimed purity limitations for acid value and hydroxyl value. The allegation of infringement is predicated on the assumption that to be a bioequivalent generic, the accused product must meet these specifications.

U.S. Patent No. 12,551,461 Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
A pharmaceutical composition comprising an active ingredient, diheptanoate, and hexano-diheptanoate, wherein the active ingredient is in the form of triheptanoin oil; The accused ANDA product is a "triheptanoin oral liquid." Plaintiffs allege that to be bioequivalent, it will have the same active ingredient and impurity profile as the branded drug. ¶40; ¶41 col. 1:17-20
wherein the triheptanoin oil has a purity greater than 98%; The allegation is that the ANDA product, to be approved as a bioequivalent generic, will necessarily meet this purity level. ¶41 claim 1
wherein the composition comprises 0.01% to 1.5% diheptanoate by weight; The allegation is that the ANDA product, to be approved as a bioequivalent generic, will necessarily fall within this specified impurity range. ¶41 claim 1
wherein the composition comprises 0.01% to 1.0% hexano-diheptanoate by weight; The allegation is that the ANDA product, to be approved as a bioequivalent generic, will necessarily fall within this specified impurity range. ¶41 claim 1
wherein glycerol is undetectable in the composition; The allegation is that the ANDA product, to be approved as a bioequivalent generic, will necessarily meet this negative limitation. ¶41 claim 1
wherein monoheptanoate is undetectable in the composition; The allegation is that the ANDA product, to be approved as a bioequivalent generic, will necessarily meet this negative limitation. ¶41 claim 1
wherein the composition comprises no more than 0.2% water by weight; The allegation is that the ANDA product, to be approved as a bioequivalent generic, will necessarily meet this specified water content limit. ¶41 claim 1
and wherein the composition is a liquid composition for oral administration to a human. The accused product is explicitly identified as a "triheptanoin oral liquid." ¶40 claim 1
  • Identified Points of Contention:
    • Scope Questions: A significant validity question may arise from the potential disconnect between the claimed invention-a "liquid" composition with a specific purity profile-and the patent's specification, which extensively describes the invention as a "solid" formulation designed to overcome the problems of prior art liquids. A defendant may argue that this constitutes a lack of written description for the claimed liquid composition.
    • Technical Questions: Infringement will depend on whether Sun's ANDA product, as specified in its confidential FDA filing, factually meets every claimed parameter. This includes not only the purity of the triheptanoin oil and the ranges of specific impurities but also the "undetectable" levels of glycerol and monoheptanoate.

V. Key Claim Terms for Construction

For the '748 Patent

  • The Term: "consists essentially of"
  • Context and Importance: This transitional phrase defines the scope of the composition. Its construction is critical to determining whether the presence of unlisted ingredients (e.g., excipients, preservatives) in the accused product places it outside the claim. Practitioners may focus on this term because the court's interpretation will decide if infringement is possible for a formulation containing anything other than triheptanoin that might affect its core function or properties.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: A plaintiff may argue that the "basic and novel properties" relate solely to the anaplerotic function of triheptanoin. The patent specification focuses on the metabolic effects of odd-carbon fatty acids '748 Patent, FIG. 4 '748 Patent, col. 19:10-21 and is largely silent on the impact of standard pharmaceutical excipients, which may suggest they do not materially alter these properties.
    • Evidence for a Narrower Interpretation: A defendant may argue that the "basic and novel properties" include the specific purity levels recited in the claim itself (acid and hydroxyl values). The explicit inclusion of these purity limitations in the claim '748 Patent, claim 1 suggests that the invention is not just about triheptanoin, but about a highly pure form of it, and any unlisted substance that affects stability or purity could be considered a material alteration.

For the '461 Patent

  • The Term: "undetectable"
  • Context and Importance: This term, used twice in claim 1, sets a critical purity threshold for glycerol and monoheptanoate. Its definition will be central to the infringement analysis. Practitioners may focus on this term because its construction-whether it means an absolute absence or a level below a certain technological limit of detection-could be dispositive of both infringement and validity (enablement).
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation (favoring Defendant): A defendant might argue for a literal, absolute "zero" or "non-existent" interpretation. The plain meaning of "undetectable" could be argued to be absolute, which would make it easy to show non-infringement if any molecule is found, or could render the claim invalid as impossible to satisfy.
    • Evidence for a Narrower Interpretation (favoring Plaintiff): A plaintiff may argue that "undetectable" must be interpreted in the context of one of ordinary skill in the art at the time of the invention, meaning not detectable by standard analytical methods then in use. The patent's own examples use the term "not detected" in analytical test results, implying a practical, measurement-based standard rather than a theoretical absolute. '461 Patent, Table 4

VI. Other Allegations

  • Indirect Infringement: The complaint alleges both induced and contributory infringement for both patents-in-suit. The basis for these allegations is that Defendants' ANDA product is intended for the patented use, has no substantial non-infringing use, and that Defendants will, upon approval, encourage infringement by marketing the product with a label that instructs physicians and patients to use it in an infringing manner. Compl. ¶¶50-51 Compl. ¶¶59-60
  • Willful Infringement: The complaint alleges willful infringement based on Defendants' pre-suit knowledge of the patents-in-suit. This knowledge is evidenced by the Paragraph IV notice letter sent by Sun to the Plaintiffs on May 26, 2026, which explicitly identified the '748 and '461 patents. Compl. ¶¶38, 42 Compl., Prayer (h)

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

  • A core issue will be one of "patent validity": can the '461 Patent, which heavily details the invention as a "solid" formulation to solve the problems of prior art liquids, provide sufficient written description and enablement to support its asserted claim to a specific "liquid" formulation, or does the specification effectively teach away from the claimed subject matter?
  • A central claim construction question will be one of "definitional interpretation": will the term "undetectable" in the '461 Patent be construed as an absolute "zero" standard, or as a practical standard relative to the limits of detection of common analytical technology at the time of the invention?
  • A key evidentiary question will be one of "factual correspondence": does the chemical composition specified in Sun's confidential ANDA filing, including its active ingredient purity and the levels of specified impurities like diheptanoate, hexano-diheptanoate, glycerol, and monoheptanoate, fall squarely within the metes and bounds of the asserted claims of both the '748 and '461 patents?
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