DCT
1:24-cv-01363
Heron Therap Inc v. Azurity Pharma Inc
I. Executive Summary and Procedural Information
- Parties & Counsel:
- Plaintiff: Heron Therapeutics, Inc. (Delaware)
- Defendant: Azurity Pharmaceuticals, Inc. (Delaware); Azurity Pharmaceuticals India LLP (India); Slayback Pharma LLC (Delaware)
- Plaintiff’s Counsel: Morris, Nichols, Arsht & Tunnell LLP
- Case Identification: 1:24-cv-01363, D. Del., 05/23/2025
- Venue Allegations: Plaintiff alleges venue is proper in the District of Delaware based on Defendants' incorporation in the state, their commission of acts of infringement within the district, and their consent to venue in related, coordinated litigation.
- Core Dispute: Plaintiff alleges that Defendant’s proposed generic aprepitant injectable emulsion, submitted to the FDA for approval, infringes three patents related to stable, injectable emulsion formulations of an NK-1 receptor antagonist.
- Technical Context: The technology concerns pharmaceutical oil-in-water emulsions designed to enable intravenous delivery of poorly water-soluble anti-emetic drugs for preventing chemotherapy-induced nausea and vomiting.
- Key Procedural History: This action was filed under the Hatch-Waxman Act following Defendant's submission of a New Drug Application (NDA) with a Paragraph IV certification, asserting non-infringement or invalidity of patents listed in the FDA's Orange Book for Plaintiff's Cinvanti® product. The complaint notes this case is coordinated with a separate civil action (No. 24-830) between the parties involving other related patents, with a trial scheduled for November 2025.
Case Timeline
| Date | Event |
|---|---|
| 2014-09-19 | ’520 Patent Priority Date |
| 2016-02-01 | ’254 and ’255 Patent Priority Date |
| 2017-11-09 | Plaintiff's Cinvanti® (aprepitant) NDA approved |
| 2023-12-12 | Plaintiff received Defendant’s Paragraph IV Notice Letter |
| 2024-07-25 | Defendant allegedly received tentative FDA approval for its NDA |
| 2024-10-15 | U.S. Patent No. 12,115,254 Issued |
| 2024-10-15 | U.S. Patent No. 12,115,255 Issued |
| 2025-05-06 | U.S. Patent No. 12,290,520 Issued |
| 2025-05-23 | Complaint Filed |
II. Technology and Patent(s)-in-Suit Analysis
U.S. Patent No. 12,115,254 - Methods of Use of Emulsion Formulations of an NK-1 Receptor Antagonist
- Patent Identification: U.S. Patent No. 12,115,254, "Methods of Use of Emulsion Formulations of an NK-1 Receptor Antagonist," issued October 15, 2024.
The Invention Explained
- Problem Addressed: The patent describes the clinical challenge that patients suffering from chemotherapy-induced nausea and vomiting (CINV) often cannot tolerate oral medications, such as the NK-1 receptor antagonist aprepitant (’254 Patent, col. 1:36-45). However, formulating poorly water-soluble drugs like aprepitant into a safe and stable injectable emulsion is technically difficult, as such emulsions must maintain a very small and consistent droplet size to avoid causing embolisms and must remain chemically stable over their shelf life (’254 Patent, col. 1:56-64; col. 2:8-35).
- The Patented Solution: The invention provides a stable, oil-in-water pharmaceutical emulsion suitable for intravenous administration (’254 Patent, Abstract). The solution comprises a specific formulation containing aprepitant, an oil, an emulsifier, a co-surfactant, and water, with a key aspect being a specific weight ratio between the emulsifier and the aprepitant, which contributes to the emulsion's stability and suitability for injection (’254 Patent, col. 2:48-58; col. 4:53-58).
- Technical Importance: This formulation enables the intravenous delivery of a critical anti-emetic agent, providing a non-oral treatment option for cancer patients for whom oral administration is not feasible (’254 Patent, col. 1:45-54).
Key Claims at a Glance
The complaint does not identify specific asserted claims but alleges infringement of one or more claims (Compl. ¶52). Independent claim 1 is representative:
- An injectable pharmaceutical emulsion, comprising:
- about 0.7-0.8 wt % aprepitant;
- an emulsifier;
- an oil;
- a co-surfactant; and
- water,
- wherein the ratio of the emulsifier to aprepitant ranges from about 20:1 to 25:1 (wt/wt %).
U.S. Patent No. 12,115,255 - Methods of Use of Emulsion Formulations of an NK-1 Receptor Antagonist
- Patent Identification: U.S. Patent No. 12,115,255, "Methods of Use of Emulsion Formulations of an NK-1 Receptor Antagonist," issued October 15, 2024.
The Invention Explained
- Problem Addressed: The patent addresses the same technical problem as the ’254 Patent: the need for a stable, injectable formulation of the poorly water-soluble anti-emetic drug aprepitant for patients undergoing chemotherapy (’255 Patent, col. 1:36-54).
- The Patented Solution: The invention is a stable oil-in-water emulsion that achieves suitability for intravenous injection through a specific combination of components defined by their concentrations and properties (’255 Patent, Abstract). Unlike the ’254 Patent's lead claim, this patent's lead claim specifies concentrations for the emulsifier and requires the emulsion to be maintained within a particular pH range, which is critical for chemical stability (’255 Patent, col. 2:8-35; col. 5:20-24).
- Technical Importance: As with the ’254 Patent, this formulation provides a non-oral delivery route for a key anti-emetic drug, simplifying CINV prophylaxis for vulnerable patients (’255 Patent, col. 1:45-54).
Key Claims at a Glance
The complaint does not identify specific asserted claims but alleges infringement of one or more claims (Compl. ¶60). Independent claim 1 is representative:
- An injectable emulsion, comprising:
- 0.7-0.8 wt % aprepitant;
- 13 wt/wt % to 20 wt/wt % of an emulsifier;
- an oil;
- a co-emulsifier which is an alcohol;
- a tonicity modifier;
- a pH modifier; and
- water;
- wherein the pH of the emulsion ranges from about 7.5 to 9.0.
U.S. Patent No. 12,290,520 - Methods of Use of Emulsion Formulations of Aprepitant
- Patent Identification: U.S. Patent No. 12,290,520, "Methods of Use of Emulsion Formulations of Aprepitant," issued May 6, 2025.
- Technology Synopsis: This patent, like the others in suit, is directed to solving the problem of creating a stable, injectable formulation for the poorly water-soluble anti-emetic drug aprepitant (’520 Patent, col. 1:28-41). The patented solution is a specific oil-in-water emulsion formulation, comprising aprepitant and dexamethasone, that is physically and chemically stable and has a sufficiently small particle size to be safe for intravenous administration to patients, particularly those undergoing chemotherapy (’520 Patent, Abstract).
- Asserted Claims: The complaint alleges infringement of "one or more claims" of the patent (Compl. ¶68).
- Accused Features: The accused features are the composition and ingredients of the Proposed Azurity Product, which the complaint alleges has the "same or equivalent ingredients in the same or equivalent amounts" as the claimed compositions (Compl. ¶¶45, 68).
III. The Accused Instrumentality
Product Identification
The accused instrumentality is the "Proposed Azurity Product," an injectable emulsion containing 130mg/18mL (7.2 mg/mL) of the active ingredient aprepitant, for which Defendant submitted New Drug Application No. 218754 to the FDA (Compl. ¶¶15, 20).
Functionality and Market Context
The Proposed Azurity Product is a generic version of Plaintiff's Cinvanti® injectable emulsion (Compl. ¶46). It is intended for the same therapeutic use: the prevention of acute and delayed nausea and vomiting associated with emetogenic cancer chemotherapy (Compl. ¶¶39, 46). The complaint alleges that the proposed product has the same active ingredient, the same or substantially the same indications, and the same or substantially the same proposed labeling as Cinvanti® (Compl. ¶46). The core of the infringement allegation is that the proposed product has the "same or equivalent ingredients in the same or equivalent amounts as the compositions claimed in one or more claims of the patents-in-suit" (Compl. ¶45).
No probative visual evidence provided in complaint.
IV. Analysis of Infringement Allegations
12,115,254 Infringement Allegations
| Claim Element (from Independent Claim 1) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| An injectable pharmaceutical emulsion, comprising: about 0.7-0.8 wt % aprepitant | The Proposed Azurity Product is an injectable emulsion containing aprepitant, allegedly in an amount equivalent to the claimed composition. | ¶¶20, 45 | col. 2:50-58 |
| an emulsifier | The Proposed Azurity Product allegedly contains the same or equivalent emulsifier as the claimed composition. | ¶45 | col. 3:9-19 |
| an oil | The Proposed Azurity Product allegedly contains the same or equivalent oil as the claimed composition. | ¶45 | col. 3:1-8 |
| a co-surfactant | The Proposed Azurity Product allegedly contains the same or equivalent co-surfactant as the claimed composition. | ¶45 | col. 3:20-21 |
| water | The Proposed Azurity Product is an emulsion that contains water in its aqueous phase. | ¶45 | col. 2:53-55 |
| wherein the ratio of the emulsifier to aprepitant ranges from about 20:1 to 25:1 (wt/wt %) | The ingredients of the Proposed Azurity Product are allegedly in the same or equivalent amounts and ratios as the claimed composition. | ¶45 | col. 4:62-67 |
- Identified Points of Contention:
- Scope Questions: A central question will be whether the term "about" as used in the concentration and ratio limitations provides sufficient breadth to read on the precise formulation of the Proposed Azurity Product.
- Technical Questions: The primary technical question is evidentiary: what is the exact formulation of the Proposed Azurity Product as disclosed in its confidential NDA? The complaint's allegation of compositional equivalence (Compl. ¶45) is made on "information and belief" and will require factual verification through discovery to determine if the product's aprepitant concentration and emulsifier-to-aprepitant ratio fall within the claimed ranges.
12,115,255 Infringement Allegations
| Claim Element (from Independent Claim 1) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| An injectable emulsion, comprising: 0.7-0.8 wt % aprepitant | The Proposed Azurity Product is an injectable emulsion containing aprepitant, allegedly in an amount equivalent to the claimed composition. | ¶¶20, 45 | col. 2:45-51 |
| 13 wt/wt % to 20 wt/wt % of an emulsifier | The Proposed Azurity Product allegedly contains an emulsifier in a concentration equivalent to that required by the claim. | ¶45 | col. 3:49-54 |
| an oil | The Proposed Azurity Product allegedly contains the same or equivalent oil as the claimed composition. | ¶45 | col. 3:1-8 |
| a co-emulsifier which is an alcohol | The Proposed Azurity Product allegedly contains the same or equivalent co-surfactant as the claimed composition. | ¶45 | col. 3:20-21 |
| a tonicity modifier | The Proposed Azurity Product is an emulsion that allegedly contains the same or equivalent tonicity modifier. | ¶45 | col. 5:58-61 |
| a pH modifier | The Proposed Azurity Product is an emulsion that allegedly contains the same or equivalent pH modifier. | ¶45 | col. 5:58-61 |
| water | The Proposed Azurity Product is an emulsion that contains water in its aqueous phase. | ¶45 | col. 5:58-61 |
| wherein the pH of the emulsion ranges from about 7.5 to 9.0 | The Proposed Azurity Product allegedly has a pH within the claimed range. | ¶45 | col. 5:20-24 |
- Identified Points of Contention:
- Scope Questions: The analysis will focus on whether the specific quantitative limitations, such as the 13-20% emulsifier concentration and the 7.5-9.0 pH range, literally cover the formulation of the Proposed Azurity Product.
- Technical Questions: Similar to the ’254 Patent, the key issue is factual. The court will need to compare the confidential specifications of the Proposed Azurity Product with the explicit numerical ranges required by Claim 1. The complaint does not provide these specific details for the accused product.
V. Key Claim Terms for Construction
For the ’254 Patent
- The Term: "ratio of the emulsifier to aprepitant"
- Context and Importance: This ratio is a central, defining limitation of claim 1. The method of calculating this ratio—including what specific compounds count as the "emulsifier"—and whether the accused product's ratio falls within the claimed "about 20:1 to 25:1" range will be a focal point of the infringement analysis.
- Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The specification provides a broad definition of "emulsifier," including a list of phospholipids such as "egg phospholipids, soy phospholipids," and others, suggesting the term is not limited to a single compound but a class (’254 Patent, col. 3:9-19).
- Evidence for a Narrower Interpretation: The detailed examples consistently use "egg lecithin (LIPOID E 80)" as the emulsifier, and the tables calculate the ratio based on this specific ingredient (’254 Patent, e.g., Table 1, col. 20:1-15). A defendant may argue that the ratio should be understood in the context of these specific embodiments.
For the ’255 Patent
- The Term: "pH of the emulsion"
- Context and Importance: Claim 1 requires the final emulsion to have a pH "from about 7.5 to 9.0." The precise meaning of this range and the conditions under which the pH is measured could determine infringement, especially if the accused product's pH is near the boundaries of this range.
- Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The specification discusses the importance of controlling pH to prevent chemical degradation over the product's shelf-life, suggesting the claimed pH range is a property the emulsion must maintain generally, not just at a single point in time (’255 Patent, col. 2:30-35).
- Evidence for a Narrower Interpretation: The patent's examples report specific pH values for the final injectable emulsions after formulation (e.g., "The pH of the injectable emulsion was 8.74") (’255 Patent, col. 20:1-3). This may support an argument that the relevant pH is the one measured on the final product at or near the time of manufacture.
VI. Other Allegations
- Indirect Infringement: The complaint alleges that if the Proposed Azurity Product is approved and marketed, Defendants will induce and contribute to infringement under 35 U.S.C. §§ 271(b) and (c) (Compl. ¶¶54, 62, 70). This allegation appears to be based on the expectation that the product's FDA-approved labeling will instruct physicians and patients to use the product in a manner that directly infringes the method claims of the patents-in-suit.
- Willful Infringement: The complaint does not include an explicit count for willful infringement or allege facts typically associated with pre-suit knowledge, such as prior correspondence or litigation involving these specific patents. The prayer for relief includes a request for a declaration of an exceptional case and attorneys' fees under 35 U.S.C. § 285 (Compl. p. 14, ¶E).
VII. Analyst’s Conclusion: Key Questions for the Case
The dispute appears to center on highly technical, fact-specific questions of chemical composition. The outcome will likely depend on the resolution of two main issues:
- A core issue will be one of factual correspondence: Does the precise, confidential formulation of Defendant's proposed generic product, as detailed in its NDA, fall within the specific quantitative ranges for ingredient concentrations, pH, and component ratios required by the asserted patent claims?
- A secondary issue will be one of claim construction: How will the court construe terms defining the boundaries of the invention, such as "about" and "ratio," and will that construction capture or exclude the specific formulation of the accused product?