DCT

1:25-cv-13632

Braintree Laboratories Inc v. Hetero USA Inc

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I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 1:25-cv-13632, D.N.J., 07/22/2025
  • Venue Allegations: Venue is alleged based on Defendant Hetero USA Inc. having a regular and established place of business in New Jersey, and all Defendants allegedly placing the accused product into the stream of commerce for distribution in the district.
  • Core Dispute: Plaintiffs allege that Defendants' submission of Abbreviated New Drug Application (ANDA) No. 220421 to market a generic version of Plaintiffs' SUTAB® colonoscopy preparation product infringes four U.S. patents.
  • Technical Context: The technology involves solid oral tablet formulations containing specific sulfate salts designed to cleanse the colon for medical procedures while minimizing electrolyte shifts.
  • Key Procedural History: This litigation was initiated under the Hatch-Waxman Act following a notice letter from Defendants, dated June 11, 2025, informing Plaintiffs of the ANDA filing. The asserted patents are listed in the FDA's "Orange Book" for SUTAB®.

Case Timeline

Date Event
2017-08-04 Priority Date for ’656, ’498, ’864, and ’697 Patents
2018-12-04 U.S. Patent No. 10,143,656 Issued
2020-11-10 FDA Approved SUTAB® New Drug Application
2021-06-15 U.S. Patent No. 11,033,498 Issued
2022-07-12 U.S. Patent No. 11,382,864 Issued
2023-05-02 U.S. Patent No. 11,638,697 Issued
2025-06-11 Defendants' ANDA Notice Letter Sent to Plaintiffs
2025-07-22 Complaint Filed

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

U.S. Patent No. 10,143,656 - “Solid Oral Sulfate Salt Formulations For Cleansing A Colon And Methods Of Using Same,” issued December 4, 2018

The Invention Explained

  • Problem Addressed: The patent describes the challenge of preparing a patient's colon for procedures like a colonoscopy. It notes that liquid preparations require ingesting large, unpalatable volumes, leading to poor patient compliance, while prior solid tablet formulations using phosphate salts were associated with risks of renal failure (Compl. ¶18; ’656 Patent, col. 1:12-50).
  • The Patented Solution: The invention is a solid oral formulation, such as a tablet, that uses a specific combination of sodium sulfate, magnesium sulfate, and potassium chloride. This combination is designed to induce a cleansing osmotic diarrhea while simultaneously balancing electrolyte levels to prevent the clinically significant electrolyte shifts that can occur with other hypertonic solutions (’656 Patent, Abstract; col. 4:46-54).
  • Technical Importance: The technology provided a path to a more convenient, tablet-based colon preparation that aimed to improve patient tolerance over large-volume liquids while avoiding the specific safety concerns of earlier phosphate-based tablets (’656 Patent, col. 1:12-20, col. 2:20-30).

Key Claims at a Glance

  • The complaint asserts infringement of at least independent claim 1 (Compl. ¶43).
  • Essential elements of Claim 1:
    • A solid oral formulation for cleansing a colon of a subject;
    • the formulation comprising from about 34.0 grams to about 38.0 grams of sodium sulfate,
    • about 4.0 grams to about 8.0 grams of magnesium sulfate, and
    • about 3.0 grams to about 5.0 grams of potassium chloride.
  • The complaint does not foreclose assertion of other claims, including dependent claims.

U.S. Patent No. 11,033,498 - “Solid Oral Sulfate Salt Formulations For Cleansing A Colon And Method Of Using Same,” issued June 15, 2021

The Invention Explained

  • Problem Addressed: Like its parent, the ’498 Patent addresses the need for a safe, effective, and tolerable solid oral formulation for colon cleansing (’498 Patent, col. 1:21-55).
  • The Patented Solution: This patent claims a specific method of using the sulfate salt formulation. It protects a split-dosing regimen where a patient takes a first dose of the composition with a specific range of active ingredients, followed by a volume of liquid, and then later administers a second, similar dose also followed by liquid, to achieve colon cleansing (’498 Patent, Abstract; col. 10:45-52).
  • Technical Importance: By claiming the specific method of administration, the patent provides a different layer of protection from the composition patent, targeting the way the product is instructed to be used by physicians and patients.

Key Claims at a Glance

  • The complaint asserts infringement of at least independent claim 1 (Compl. ¶51).
  • Essential elements of Claim 1:
    • A method of cleansing the colon, comprising:
    • a) administering a first dose of a colon cleansing composition in an oral dosage form comprising about 17.75 g of sodium sulfate, about 2.7 g of magnesium sulfate, and about 2.25 g of potassium chloride;
    • b) administering a first volume of liquid within two hours of the first dose;
    • c) administering a second dose of the same composition; and
    • d) administering a second volume of liquid within two hours of the second dose.
  • The complaint does not foreclose assertion of other claims, including dependent claims.

Multi-Patent Capsules

  • U.S. Patent No. 11,382,864 - “Solid Oral Sulfate Salt Formulations For Cleansing A Colon And Method Of Using Same,” issued July 12, 2022 (Compl. ¶28).

    • Technology Synopsis: This patent claims a more detailed method of cleansing the colon than the ’498 Patent. The claims recite administering specific doses of the sulfate salt composition along with administering specific volumes of water both while taking the doses and after taking the doses (’864 Patent, col. 22:1-29). This protects a highly specific administration protocol.
    • Asserted Claims: At least independent claim 1 (Compl. ¶59).
    • Accused Features: The proposed labeling for Defendants' generic product is alleged to instruct users to perform this specific multi-step method of administration (Compl. ¶62).

  • U.S. Patent No. 11,638,697 - “Solid Oral Sulfate Salt Formulations For Cleansing A Colon And Methods Of Using Same,” issued May 2, 2023 (Compl. ¶32).

    • Technology Synopsis: This patent returns to claiming a solid oral formulation, but with narrower, more specific ranges than the parent ’656 Patent. The invention is a formulation that comprises amounts of the three key salts that correspond to a specific preferred embodiment described in the specification (’697 Patent, col. 21:7-12). This provides a "picture claim" protection for the precise commercial formulation.
    • Asserted Claims: At least independent claim 1 (Compl. ¶67, 69).
    • Accused Features: The composition of Defendants' proposed generic product itself is alleged to infringe, as it purportedly contains the same specific amounts of the three active ingredients (Compl. ¶67).

III. The Accused Instrumentality

  • Product Identification: Defendants' proposed generic version of SUTAB®, which is the subject of ANDA No. 220421 (Compl. ¶2, 36).
  • Functionality and Market Context: The accused product is a solid oral tablet intended to be a generic equivalent to Braintree's SUTAB®, an osmotic laxative used to cleanse the colon prior to a colonoscopy (Compl. ¶18, 37). The complaint alleges that the proposed generic contains 1.479 g of sodium sulfate, 0.225 g of magnesium sulfate, and 0.188 g of potassium chloride per tablet and is bioequivalent to SUTAB® (Compl. ¶37). It is alleged to have the same active ingredients, dosage form, and route of administration as the branded product, positioning it to compete directly with SUTAB® upon FDA approval (Compl. ¶37). No probative visual evidence provided in complaint.

IV. Analysis of Infringement Allegations

’656 Patent Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
A solid oral formulation for cleansing a colon of a subject; The accused product is a solid oral tablet formulation intended for cleansing the colon. ¶37, ¶18 col. 11:65
the formulation comprising from about 34.0 grams to about 38.0 grams of sodium sulfate, The complaint alleges each tablet contains 1.479 g of sodium sulfate. A full 24-tablet course, as used for SUTAB®, would contain 35.5 g, which falls within the claimed range. ¶37, ¶43 col. 11:66-67
about 4.0 grams to about 8.0 grams of magnesium sulfate, and The complaint alleges each tablet contains 0.225 g of magnesium sulfate. A full 24-tablet course would contain 5.4 g, which falls within the claimed range. ¶37, ¶43 col. 11:67-col. 12:1
about 3.0 grams to about 5.0 grams of potassium chloride. The complaint alleges each tablet contains 0.188 g of potassium chloride. A full 24-tablet course would contain approximately 4.5 g, which falls within the claimed range. ¶37, ¶43 col. 12:1-2
  • Identified Points of Contention:
    • Scope Questions: A potential question is whether the "formulation" as claimed refers to the total dosage administered for a cleansing procedure (e.g., 24 tablets) or to a single tablet. The complaint's allegations, which rely on the total quantity of ingredients in a full course of treatment, suggest Plaintiffs' position that the claim covers the full dosage regimen.

’498 Patent Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
a) administering a first dose...comprising about 17.75 grams of sodium sulfate, about 2.7 grams of magnesium sulfate, and about 2.25 grams of potassium chloride; The complaint alleges Defendants' proposed labeling will instruct users to take a first dose of 12 tablets. This dose would contain approximately 17.75 g of sodium sulfate, 2.7 g of magnesium sulfate, and 2.26 g of potassium chloride, meeting the claim limitations. ¶37, ¶54 col. 21:3-8
b) administering a first volume of liquid within two hours of the first dose; The proposed product labeling is alleged to be "especially made or adapted for use in infringing the '498 Patent," which raises the question of whether it will instruct users to consume liquid with the first dose as required by the claim. ¶54 col. 21:9-10
c) administering a second dose of the colon cleansing composition...; The proposed labeling is alleged to instruct users to take a second dose of 12 tablets containing the same composition as the first dose. ¶37, ¶54 col. 21:11-16
d) administering a second volume of a liquid within two hours of the second dose... It is alleged the proposed labeling will instruct users to consume liquid with the second dose as required by the claim. ¶54 col. 21:17-19
  • Identified Points of Contention:
    • Technical Questions: A central factual question for the infringement analysis of this method patent will be the precise instructions contained in the Defendants' proposed product labeling. The complaint alleges on information and belief that the label will induce infringement, but the content of that label will be a key piece of evidence.

V. Key Claim Terms for Construction

  • The Term: "about" (’656 Patent, Claim 1)

    • Context and Importance: This term defines the permissible quantitative range for each of the three active ingredients in the claimed formulation. While the accused product's alleged composition appears to fall squarely within the numerical ranges, the construction of "about" is a standard point of contention in chemical composition claims and its scope could become critical if discovery reveals manufacturing variations or if the validity of the patent is challenged.
    • Intrinsic Evidence for Interpretation:
      • Evidence for a Broader Interpretation: The specification repeatedly uses the term "about" when describing the formulation ranges, suggesting the inventors intended to claim a degree of numerical flexibility rather than strict endpoints (’656 Patent, col. 3:59-63).
      • Evidence for a Narrower Interpretation: The patent provides tables with highly specific formulations used in clinical studies, such as "35.5" grams of sodium sulfate and "5.4" grams of magnesium sulfate (’656 Patent, Table 1). A party could argue these specific examples inform the meaning of "about" and suggest it does not extend far beyond the stated numerical values.

  • The Term: "consisting essentially of" (’498 Patent, Claim 1)

    • Context and Importance: This transitional phrase restricts the claimed method to one where the administered composition contains the three recited sulfate salts and any other unlisted components that do not materially affect the basic and novel properties of the invention—namely, colon cleansing via osmotic action without significant electrolyte shifts. Practitioners may focus on this term because its construction will determine whether any additional ingredients or excipients in the accused generic product are sufficient to take it outside the claim's scope.
    • Intrinsic Evidence for Interpretation:
      • Evidence for a Broader Interpretation: The specification discloses embodiments that include additional components such as sodium caprylate and polyethylene glycol, suggesting that the presence of such excipients does not necessarily "materially affect" the invention's core properties (’498 Patent, col. 5:44-50; col. 8:1-12).
      • Evidence for a Narrower Interpretation: The background and summary emphasize that a key aspect of the invention is the unique balance of the three specific sulfate salts to achieve the desired effect (’498 Patent, col. 2:54-62). A party could argue that any additional component with osmotic or electrolytic properties would inherently affect this balance, supporting a narrower construction where very few, if any, other active components are permitted.

VI. Other Allegations

  • Indirect Infringement: The complaint alleges that Defendants will induce and contribute to infringement of all asserted patents (Compl. ¶47, 55, 63, 71). For the method claims in the ’498 and ’864 patents, the inducement theory is based on the allegation that Defendants' proposed product labeling will instruct physicians and patients to perform the patented methods of administration (Compl. ¶54, 62). The complaint further alleges the product is "especially made or adapted for use in infringing" the patents and is "not suitable for any substantial noninfringing use" (Compl. ¶46, 54, 62, 70).
  • Willful Infringement: The complaint does not use the term "willful." However, it alleges for each patent that "Defendants had actual and constructive knowledge" of the patent prior to filing their ANDA and "were aware that the filing of ANDA No. 220421 with the FDA constituted an act of infringement" (Compl. ¶44, 52, 60, 68). These allegations may form the basis for a later claim for enhanced damages.

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

  • A core issue will be one of evidentiary proof for indirect infringement: For the asserted method claims, will the specific instructions in the Defendants' proposed product label, once produced in discovery, map directly onto all steps of the claimed methods, including the detailed water intake regimens of the ’864 patent?
  • A second key question will be one of claim scope and validity: Given the direct compositional overlap alleged between the accused generic and the asserted formulation claims, the case may turn on the validity of those claims. A central issue for the court will likely be whether the specific three-salt combination and ratios, designed to balance cleansing efficacy with electrolyte safety, represent a non-obvious advance over prior art osmotic laxatives known at the time of the invention.