DCT
1:25-cv-13133
Azurity Pharmaceuticals Inc v. Lupin Ltd
Key Events
Amended Complaint
I. Executive Summary and Procedural Information
- Parties & Counsel:
- Plaintiff: Azurity Pharmaceuticals, Inc. (Delaware)
- Defendant: Lupin Ltd. (India) and Lupin Pharmaceuticals, Inc. (Delaware)
- Plaintiff’s Counsel: Robinson Miller LLC
- Case Identification: [Azurity Pharmaceuticals, Inc.](https://ai-lab.exparte.com/party/azurity-pharmaceuticals-inc) v. [Lupin Ltd.](https://ai-lab.exparte.com/party/lupin-ltd), et al., 1:25-cv-13133, D.N.J., 12/11/2025
- Venue Allegations: Plaintiff alleges venue is proper in the District of New Jersey because Defendant Lupin Pharmaceuticals maintains a regular and established place of business in Somerset, New Jersey, which includes its "first and only commercial manufacturing facility in the United States."
- Core Dispute: Plaintiff alleges that Defendants' filing of an Abbreviated New Drug Application (ANDA) to market a generic version of Plaintiff's SUFLAVE® drug product constitutes an act of infringement of three patents related to colon cleansing compositions and methods of their administration.
- Technical Context: The technology concerns osmotic laxative formulations containing polyethylene glycol (PEG) and specific sulfate salts, designed for cleansing the colon prior to medical procedures such as colonoscopies.
- Key Procedural History: This action arises under the Hatch-Waxman Act, triggered by Defendants' submission of ANDA No. 220363 and issuance of a notice letter to the New Drug Application (NDA) holder. The complaint notes that Plaintiff Azurity acquired the U.S. rights to SUFLAVE® from the original NDA holder, Braintree Laboratories, Inc., during the pendency of the suit.
Case Timeline
| Date | Event |
|---|---|
| 2023-06-15 | Earliest Priority Date for all Asserted Patents |
| 2023-06-15 | FDA Approval of SUFLAVE® (NDA No. 215344) |
| 2025-03-04 | U.S. Patent No. 12,239,659 Issues |
| 2025-05-06 | U.S. Patent No. 12,290,529 Issues |
| 2025-05-27 | Defendants send Notice Letter regarding ANDA filing |
| 2025-10-07 | U.S. Patent No. 12,433,914 Issues |
| 2025-11-17 | Azurity acquires U.S. rights to SUFLAVE® |
| 2025-11-18 | Defendants send Supplemental Notice Letter |
| 2025-12-11 | First Amended Complaint Filing Date |
II. Technology and Patent(s)-in-Suit Analysis
U.S. Patent No. 12,239,659 - "Methods of Administering Safe Colon Cleansing Compositions"
The Invention Explained
- Problem Addressed: The patent describes shortcomings with prior art colon cleansing preparations, including the poor patient compliance associated with large-volume, salty-tasting solutions and the safety risks (e.g., renal failure) associated with smaller-volume phosphate-based products ('659 Patent, col. 1:21-48). It also notes that "off-label" preparations combining laxatives like MiraLax® with sports drinks require adjunct stimulant laxatives and can create electrolyte imbalances ('659 Patent, col. 1:49-2:9).
- The Patented Solution: The invention is a method for administering a composition of polyethylene glycol (PEG) and a specific combination of sulfate salts (sodium sulfate and magnesium sulfate) that cleanses the colon effectively. This formulation is designed to improve taste and tolerability, thereby eliminating the need for adjunct stimulant laxatives like bisacodyl, while maintaining a satisfactory patient safety profile by balancing electrolytes ('659 Patent, col. 2:10-28; Abstract).
- Technical Importance: The claimed method seeks to improve patient compliance and safety for a widely performed medical preparatory procedure by providing a well-tolerated, effective, and safer formulation ('659 Patent, col. 2:10-28).
Key Claims at a Glance
- The complaint asserts infringement of at least independent claim 1 (Compl. ¶38).
- Claim 1 recites a method of cleansing a colon comprising the steps of:
- Providing a first container with a first portion of a first dose (containing polyethylene glycol, sodium sulfate, potassium chloride, magnesium sulfate, sodium chloride, flavor, and sweeteners).
- Providing a second container with a second portion of the first dose (containing malic acid and citric acid).
- Mixing the contents of the first two containers with water to form a first dose.
- Consuming the first dose.
- Repeating these steps with third and fourth containers to form and consume a second dose.
- Wherein the consumption of the two doses cleanses the colon and "does not cause a sodium balance of -50.00 mEq/L or greater in the patient."
- The complaint does not explicitly reserve the right to assert dependent claims for this patent.
U.S. Patent No. 12,290,529 - "Methods of Administering Safe Colon Cleansing Compositions"
The Invention Explained
- Problem Addressed: The technical problem is identical to that described in the ’659 Patent: the need for a safe, effective, and tolerable colon cleansing preparation that improves patient compliance and avoids the risks of prior art formulations (’529 Patent, col. 1:11-2:9).
- The Patented Solution: This patent claims a colon cleansing product (or kit) rather than a method. The product comprises four separate containers holding the components for a split-dose regimen. Two containers hold the PEG and salt mixture, while the other two hold malic and citric acids. This configuration allows for the components to be mixed by the user prior to administration, with the complete formulation designed to cleanse the colon without causing a significant negative sodium balance in the patient (’529 Patent, Abstract; col. 18:24-48).
- Technical Importance: The claimed product provides the necessary components for the improved colon cleansing method in a pre-packaged kit, ensuring proper dosing and simplifying administration for the patient (’529 Patent, col. 11:27-31).
Key Claims at a Glance
- The complaint asserts infringement of at least independent claim 1 (Compl. ¶46).
- Claim 1 recites a colon cleansing product comprising:
- (a) A first container with specific amounts of polyethylene glycol 3350, sodium sulfate, potassium chloride, magnesium sulfate, and sodium chloride.
- (b) A second container with malic acid and citric acid.
- (c) A third container with the same components as the first.
- (d) A fourth container with the same components as the second.
- The claim further specifies that the product includes lemon-lime flavor, sucralose, and neotame, and is formulated so that the combined doses "cleanse a colon of a subject without causing a sodium balance of -50.00 mEq/L or greater in the subject."
- The complaint does not explicitly reserve the right to assert dependent claims for this patent.
U.S. Patent No. 12,433,914 - "Methods of Administering Safe Colon Cleansing Compositions"
- Technology Synopsis: This patent claims methods for cleansing a patient's colon by administering a split-dose formulation of polyethylene glycol, sulfate salts, and other electrolytes. The invention is directed at providing effective purgation for diagnostic procedures while avoiding clinically significant electrolyte shifts, particularly relating to sodium balance ('914 Patent, Abstract; col. 18:20-44).
- Asserted Claims: The complaint asserts at least independent claim 1 (Compl. ¶54).
- Accused Features: Defendants’ proposed generic version of SUFLAVE®, containing polyethylene glycol 3350, sodium sulfate, potassium chloride, magnesium sulfate, and sodium chloride, which would be administered according to its proposed labeling, is alleged to infringe the claimed methods (Compl. ¶¶54, 56).
III. The Accused Instrumentality
Product Identification
- Defendants' proposed generic version of Plaintiff's SUFLAVE® drug product, which is the subject of ANDA No. 220363 filed with the U.S. Food and Drug Administration (FDA) (Compl. ¶¶1, 30).
Functionality and Market Context
- The accused product is a colon cleansing solution indicated for use in adults in preparation for a colonoscopy (Compl. ¶16). The complaint alleges that Defendants have represented to the FDA that their proposed generic product contains the same active ingredients (polyethylene glycol 3350, sodium sulfate, potassium chloride, magnesium sulfate, and sodium chloride), route of administration, dosage form, and strengths as SUFLAVE®, and that it is bioequivalent to SUFLAVE® (Compl. ¶32). If approved, Defendants intend to manufacture, market, and sell this product in the United States (Compl. ¶12).
- No probative visual evidence provided in complaint.
IV. Analysis of Infringement Allegations
’659 Patent Infringement Allegations
| Claim Element (from Independent Claim 1) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| (a) providing a first container comprising a first portion of a first dose of a colon cleansing product comprising about 178.7 grams of polyethylene glycol... | The composition of Defendants' proposed generic product, as described in their ANDA submission, contains the recited ingredients. | ¶38 | col. 18:25-31 |
| (b) providing a second container comprising a second portion of the first dose of a colon cleansing product comprising malic acid and citric acid; | The composition of Defendants' proposed generic product, as described in their ANDA submission, contains the recited ingredients. | ¶38 | col. 18:32-35 |
| (d) consuming the first dose; | The proposed labeling for Defendants' generic product will instruct patients to consume the product, thereby inducing infringement of the method steps. | ¶41 | col. 18:40 |
| (h) consuming the second dose, wherein consumption of the first dose and second dose cleanses the colon...and does not cause a sodium balance of -50.00 mEq/L or greater in the patient. | The proposed generic product is alleged to be bioequivalent to SUFLAVE®, and its intended use is for colon cleansing. This bioequivalence suggests it will have the same physiological effect, including the claimed sodium balance profile. | ¶¶32, 40 | col. 18:45-51 |
’529 Patent Infringement Allegations
| Claim Element (from Independent Claim 1) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| A colon cleansing product comprising: (a) a first container comprising a first portion of a first dose of a colon cleansing product comprising about 178.7 grams of polyethylene glycol 3350... | Defendants' proposed generic product, as described in their ANDA, is alleged to have the same components as SUFLAVE®, thereby meeting the compositional requirements of the claimed product. | ¶46 | col. 18:25-30 |
| (b) a second container comprising a second portion of the first dose...comprising malic acid and citric acid; | Defendants' proposed generic product is alleged to have the same components as SUFLAVE®, thereby meeting the compositional requirements of the claimed product. | ¶46 | col. 18:31-33 |
| wherein the colon cleansing product further comprises lemon-lime flavor, sucralose, and neotame; | The proposed generic product is a copy of SUFLAVE®, which contains these flavoring agents. | ¶46 | col. 18:40-41 |
| and wherein the colon cleansing product is formulated so that the combination of the first dose and second dose cleanse a colon of a subject without causing a sodium balance of -50.00 mEq/L or greater in the subject. | As an alleged bioequivalent copy of SUFLAVE®, the generic product is necessarily formulated to produce the same clinical and physiological outcome as the branded product, which is covered by this claim limitation. | ¶¶32, 46 | col. 18:42-48 |
Identified Points of Contention
- Scope Questions: The infringement analysis for both the '659 and ’529 patents may turn on the construction of the negative functional limitation "does not cause a sodium balance of -50.00 mEq/L or greater." This raises the question of whether this limitation must be met in every patient, or if it refers to an average outcome in a clinical population.
- Technical Questions: What evidence does the complaint provide that Defendants' product will meet the specific physiological outcome required by the claims? The allegations rely on the assertion that the generic product is bioequivalent and has the same active ingredients as SUFLAVE® (Compl. ¶32), which suggests the infringement case will depend on data submitted in the ANDA.
V. Key Claim Terms for Construction
- The Term: "without causing a sodium balance of -50.00 mEq/L or greater in the subject" (’529 Patent, cl. 1) / "does not cause a sodium balance of -50.00 mEq/L or greater in the patient" (’659 Patent, cl. 1).
- Context and Importance: This negative functional limitation is a critical component of the independent claims of both lead patents. Its construction is central to the dispute, as it defines a specific physiological outcome that the accused product must avoid. Practitioners may focus on this term because its patient-dependent nature could be a basis for an indefiniteness challenge under 35 U.S.C. § 112.
- Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The claims use general terms like "a subject" and "the patient," which could be argued to apply generally to the product's intended effect on a typical user, rather than requiring the outcome in every single individual.
- Evidence for a Narrower Interpretation: The specification provides detailed clinical data showing how this balance was measured and achieved in a test population ('659 Patent, Table 2, col. 17-18). The patent describes how an earlier formulation (BLI4900-4) had a negative sodium balance and was reformulated into the final version (BLI4900-5) to correct this, indicating that the -50.00 mEq/L threshold is a specific, data-driven boundary tied to the clinical results disclosed in the patent ('659 Patent, col. 18:32-41).
VI. Other Allegations
- Indirect Infringement: The complaint alleges that Defendants will induce infringement by instructing physicians and patients, via the proposed product labeling, to administer the generic product in a manner that directly infringes the asserted method claims (Compl. ¶41, 57). It further alleges contributory infringement, stating the proposed product is especially made or adapted for this infringing use and is not suitable for a substantial non-infringing use (Compl. ¶41, 49, 57).
- Willful Infringement: The complaint alleges that Defendants had "actual and constructive knowledge" of the asserted patents prior to filing their ANDA (Compl. ¶39, 47, 55). This knowledge is predicated on the patents being listed in the FDA's "Orange Book" for SUFLAVE® (Compl. ¶17), which provides the basis for an allegation of willful infringement.
VII. Analyst’s Conclusion: Key Questions for the Case
- A core issue will be one of claim validity and scope: can the negative functional limitation "does not cause a sodium balance of -50.00 mEq/L or greater," which describes a physiological outcome in a patient, be construed as a sufficiently definite and objective standard to be enforceable against an ANDA filer?
- A key evidentiary question will be one of proving infringement via bioequivalence: will Defendants' ANDA submission, particularly data demonstrating the generic product's bioequivalence to SUFLAVE®, be sufficient to establish that the accused product will necessarily meet the specific compositional and functional limitations of the asserted claims?