1:26-cv-00999
Heron Therap Inc v. Long Grove Pharma LLC
I. Executive Summary and Procedural Information
- Parties & Counsel:
- Plaintiff: Heron Therapeutics, Inc. (Delaware)
- Defendant: Long Grove Pharmaceuticals, LLC (Delaware) and Capstone Development Services Company, LLC (Delaware)
- Plaintiff's Counsel: Morris, Nichols, Arsht & Tunnell LLP
- Case Identification: 1:26-cv-00999, D. Del., 08/07/2026
- Venue Allegations: Venue is asserted in the District of Delaware based on both Defendants being incorporated in Delaware and having allegedly committed acts of infringement in the district.
- Core Dispute: Plaintiff alleges that Defendants' submission of a New Drug Application to the FDA for a generic version of Plaintiff's Cinvanti® product constitutes an act of infringement of thirteen patents related to injectable emulsion formulations of the anti-nausea drug aprepitant.
- Technical Context: The patents relate to stable oil-in-water emulsion formulations for intravenous administration of poorly soluble drugs, specifically for treating and preventing chemotherapy-induced nausea and vomiting (CINV).
- Key Procedural History: The complaint notes that in a prior case, Heron Therapeutics Inc v. Azurity Pharmaceuticals Inc, the District of Delaware found claims of two related patents (U.S. Patent Nos. 12,115,255 and 12,290,520, which are also asserted in this action) invalid for lack of written description. That decision is currently on appeal to the Federal Circuit. This history may influence the court's analysis of the adequacy of the written description supporting the claims of the patents-in-suit in the current case.
Case Timeline
| Date | Event |
|---|---|
| 2014-09-19 | Priority Date for all Patents-in-Suit |
| 2017-02-07 | U.S. Patent No. 9,561,229 Issues |
| 2017-11-07 | U.S. Patent No. 9,808,465 Issues |
| 2017-11-09 | Plaintiff's Cinvanti® (NDA No. 209296) Approved by FDA |
| 2018-05-22 | U.S. Patent Nos. 9,974,742, 9,974,793, and 9,974,794 Issue |
| 2019-12-10 | U.S. Patent No. 10,500,208 Issues |
| 2020-04-21 | U.S. Patent No. 10,624,850 Issues |
| 2021-03-23 | U.S. Patent No. 10,953,018 Issues |
| 2021-11-16 | U.S. Patent No. 11,173,118 Issues |
| 2023-09-05 | U.S. Patent No. 11,744,800 Issues |
| 2024-10-15 | U.S. Patent Nos. 12,115,254 and 12,115,255 Issue |
| 2025-05-06 | U.S. Patent No. 12,290,520 Issues |
| 2026-06-01 | D. Del. rules claims of '255 and '520 patents invalid in prior litigation |
| 2026-06-26 | Plaintiff receives Defendants' Paragraph IV Notice Letter |
| 2026-08-07 | Complaint Filed |
II. Technology and Patent(s)-in-Suit Analysis
The complaint asserts thirteen patents. The first two are analyzed in full below. The specifications of the patents-in-suit are substantially similar; U.S. Patent No. 10,500,208 (the '208 Patent), a continuation of the '229 Patent, is used as a representative specification for analysis.
U.S. Patent No. 9,561,229 - "Emulsion Formulations of Aprepitant"
- Patent Identification: U.S. Patent No. 9,561,229 ("the '229 Patent"), "Emulsion Formulations of Aprepitant," issued February 7, 2017 Compl. ¶24
The Invention Explained
- Problem Addressed: The drug aprepitant is effective for preventing nausea and vomiting from chemotherapy, but its poor solubility and permeability characteristics make it very difficult to formulate as a liquid for intravenous administration, which is a preferred route for patients already experiencing nausea Compl. ¶39 '208 Patent, col. 1:45-52
- The Patented Solution: The invention is a stable, oil-in-water emulsion that suspends aprepitant for intravenous injection. The formulation comprises an oil phase (containing aprepitant, an oil like soybean oil, an emulsifier, and a co-surfactant) and an aqueous phase (containing water and agents to adjust tonicity and pH), which remain stable for long periods '208 Patent, abstract '208 Patent, col. 2:38-44 The specific ratios and components are designed to create a stable emulsion with a very small droplet size suitable for injection into the bloodstream '208 Patent, col. 1:60-67
- Technical Importance: This technology provided the first non-oral, injectable formulation of aprepitant, offering a critical therapeutic option for cancer patients unable to take oral medication due to emesis '208 Patent, abstract
Key Claims at a Glance
- The complaint does not identify specific asserted claims, alleging infringement of "one or more claims" of the '229 Patent Compl. ¶50 Claim 1 of the related '208 Patent is representative of the core composition claims.
- Key elements of Claim 1 of the '208 Patent include:
- An injectable emulsion comprising aprepitant.
- An emulsifier at a concentration of 11 wt/wt% to 15 wt/wt%.
- An oil.
- A co-emulsifier which is an alcohol.
- A tonicity modifier, a pH modifier, and water.
- A final pH ranging from about 7.5 to 9.0.
- A requirement that the emulsion is "physically stable."
U.S. Patent No. 9,808,465 - "Emulsion Formulations of Aprepitant"
- Patent Identification: U.S. Patent No. 9,808,465 ("the '465 Patent"), "Emulsion Formulations of Aprepitant," issued November 7, 2017 Compl. ¶25
The Invention Explained
- Problem Addressed: As with the '229 Patent, the '465 Patent addresses the challenge of creating a stable, injectable liquid formulation for the poorly soluble drug aprepitant '208 Patent, col. 1:45-52
- The Patented Solution: The '465 Patent claims methods of using the aprepitant emulsion formulations to treat or prevent emesis. This is distinct from the composition claims of other patents in the family. For example, U.S. Patent No. 11,744,800, a related method-of-use patent, describes administering the injectable emulsion to prevent post-operative nausea and vomiting '800 Patent, abstract
- Technical Importance: The invention provides a specified medical use for the novel aprepitant formulations, targeting a significant unmet need for patients undergoing chemotherapy or surgery '800 Patent, col. 9:1-5
Key Claims at a Glance
- The complaint does not identify specific asserted claims, alleging infringement of "one or more claims" of the '465 Patent Compl. ¶59 Claim 1 of the related '800 Patent is representative of the method-of-use claims.
- Key elements of Claim 1 of the '800 Patent include:
- A method for preventing post-operative nausea and vomiting in a subject.
- The step of intravenously administering an injectable pharmaceutical emulsion.
- The emulsion comprises aprepitant, an emulsifier, an oil, a co-surfactant (alcohol), a tonicity agent, a pH modifier, and water.
- The ratio of the emulsifier to aprepitant ranges from about 18:1 to 22:1 (wt/wt%).
- The pH of the emulsion ranges from about 7.5 to 9.0.
Multi-Patent Capsules
Patent Identification: U.S. Patent No. 9,974,742 ("the '742 Patent"), "Emulsion Formulations of an NK-1 Receptor Antagonist and Uses Thereof," issued May 22, 2018 Compl. ¶26
Technology Synopsis: The '742 Patent covers emulsion formulations for a broader class of NK-1 receptor antagonists (of which aprepitant is one example), as well as methods of using them '850 Patent, abstract The formulations are designed for intravenous administration to treat emesis.
Asserted Claims: The complaint is non-specific Compl. ¶68; claims cover both compositions and methods of use.
Accused Features: Defendants' proposed generic aprepitant emulsion product Compl. ¶68
Patent Identification: U.S. Patent No. 9,974,793 ("the '793 Patent"), "Emulsion Formulations of Aprepitant," issued May 22, 2018 Compl. ¶27
Technology Synopsis: This patent claims specific, stable, injectable oil-in-water emulsion formulations of aprepitant with particular component ratios and properties for treating emesis '208 Patent, abstract
Asserted Claims: The complaint is non-specific Compl. ¶77; claims cover pharmaceutical compositions.
Accused Features: Defendants' proposed generic aprepitant emulsion product Compl. ¶77
Patent Identification: U.S. Patent No. 9,974,794 ("the '794 Patent"), "Emulsion Formulations of Aprepitant," issued May 22, 2018 Compl. ¶28
Technology Synopsis: This patent claims specific, stable, injectable oil-in-water emulsion formulations of aprepitant with particular component ratios and properties for treating emesis '208 Patent, abstract
Asserted Claims: The complaint is non-specific Compl. ¶86; claims cover pharmaceutical compositions.
Accused Features: Defendants' proposed generic aprepitant emulsion product Compl. ¶86
Patent Identification: U.S. Patent No. 10,500,208 ("the '208 Patent"), "Emulsion Formulations of Aprepitant," issued December 10, 2019 Compl. ¶29
Technology Synopsis: This patent claims injectable aprepitant emulsions with specific weight-percent ranges for the emulsifier and a defined pH range, which are designated as "physically stable" '208 Patent, claim 1
Asserted Claims: The complaint is non-specific Compl. ¶95; claims cover pharmaceutical compositions.
Accused Features: Defendants' proposed generic aprepitant emulsion product Compl. ¶95
Patent Identification: U.S. Patent No. 10,624,850 ("the '850 Patent"), "Emulsion Formulations of an NK-1 Receptor Antagonist and Uses Thereof," issued April 21, 2020 Compl. ¶30
Technology Synopsis: This patent claims methods of treating emesis by administering an injectable emulsion of an NK-1 receptor antagonist, where the emulsion has specific component ratios and pH properties '850 Patent, claim 1
Asserted Claims: The complaint is non-specific Compl. ¶104; claims cover methods of treatment.
Accused Features: The intended use of Defendants' proposed generic aprepitant emulsion product Compl. ¶104
Patent Identification: U.S. Patent No. 10,953,018 ("the '018 Patent"), "Emulsion Formulations of Aprepitant," issued March 23, 2021 Compl. ¶31
Technology Synopsis: This patent claims stable, injectable aprepitant emulsions with specific ratios of the emulsifier to aprepitant and oil to aprepitant, intended for treating nausea and vomiting '018 Patent, claim 1
Asserted Claims: The complaint is non-specific Compl. ¶113; claims cover pharmaceutical compositions.
Accused Features: Defendants' proposed generic aprepitant emulsion product Compl. ¶113
Patent Identification: U.S. Patent No. 11,173,118 ("the '118 Patent"), "Emulsion Formulations of an NK-1 Receptor Antagonist and Uses Thereof," issued November 16, 2021 Compl. ¶32
Technology Synopsis: The patent claims injectable emulsions containing an NK-1 receptor antagonist (other than aprepitant) with specific component ratios, such as the ratio of emulsifier to the antagonist '118 Patent, claim 1
Asserted Claims: The complaint is non-specific Compl. ¶122; claims cover pharmaceutical compositions.
Accused Features: Defendants' proposed generic aprepitant emulsion product Compl. ¶122
Patent Identification: U.S. Patent No. 11,744,800 ("the '800 Patent"), "Methods of Use of Emulsion Formulations of an NK-1 Receptor Antagonist," issued September 5, 2023 Compl. ¶33
Technology Synopsis: This patent claims methods of preventing post-operative nausea and vomiting by intravenously administering a specific injectable emulsion of an NK-1 receptor antagonist like aprepitant '800 Patent, abstract '800 Patent, claim 1
Asserted Claims: The complaint is non-specific Compl. ¶131; claims cover methods of use.
Accused Features: The intended use of Defendants' proposed generic aprepitant emulsion product Compl. ¶131
Patent Identification: U.S. Patent No. 12,115,254 ("the '254 Patent"), "Methods of Use of Emulsion Formulations of an NK-1 Receptor Antagonist," issued October 15, 2024 Compl. ¶34
Technology Synopsis: This patent claims methods of treating emesis by administering an injectable emulsion of aprepitant with specific component ratios, including the ratio of the emulsifier to the antagonist '254 Patent, claim 1
Asserted Claims: The complaint is non-specific Compl. ¶140; claims cover methods of use.
Accused Features: The intended use of Defendants' proposed generic aprepitant emulsion product Compl. ¶140
Patent Identification: U.S. Patent No. 12,115,255 ("the '255 Patent"), "Methods of Use of Emulsion Formulations of an NK-1 Receptor Antagonist," issued October 15, 2024 Compl. ¶35
Technology Synopsis: This patent claims methods for preventing CINV by administering an injectable emulsion of an NK-1 receptor antagonist, specifying component ratios and administration details '255 Patent, claim 1
Asserted Claims: The complaint is non-specific Compl. ¶150; claims cover methods of use.
Accused Features: The intended use of Defendants' proposed generic aprepitant emulsion product Compl. ¶150
Patent Identification: U.S. Patent No. 12,290,520 ("the '520 Patent"), "Methods of Use of Emulsion Formulations of Aprepitant," issued May 6, 2025 Compl. ¶36
Technology Synopsis: This patent claims methods of preventing CINV by administering an aprepitant emulsion with specific formulations, including defined amounts of egg lecithin and soybean oil '520 Patent, claim 1
Asserted Claims: The complaint is non-specific Compl. ¶160; claims cover methods of use.
Accused Features: The intended use of Defendants' proposed generic aprepitant emulsion product Compl. ¶160
III. The Accused Instrumentality
- Product Identification: The accused instrumentality is "Defendants' Proposed Product," an injectable emulsion containing 130mg/18mL (7.2 mg/mL) of aprepitant for which Defendants seek FDA approval under New Drug Application (NDA) No. 220343 Compl. ¶41
- Functionality and Market Context: The complaint alleges that the Defendants' Proposed Product is a generic version of Plaintiff's Cinvanti® product Compl. ¶42 The action was triggered by Defendants' submission of an NDA under 21 U.S.C. § 355(b)(2), which is a pathway for drugs that are similar to a previously approved drug Compl. ¶41 The complaint alleges the proposed product has the same active ingredient, indications, and labeling as Cinvanti®, and that it will be marketed for the prevention of chemotherapy-induced nausea and vomiting upon FDA approval (Compl. ¶¶39; Compl. ¶43). No probative visual evidence provided in complaint.
IV. Analysis of Infringement Allegations
The complaint makes only general allegations of infringement and does not provide a claim chart or detailed infringement theory. The following tables are constructed based on the general description of the Defendants' Proposed Product and representative claims from the patent family.
'229 Patent Infringement Allegations
(Based on Claim 1 of representative '208 Patent)
| Claim Element (from Independent Claim 1) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| An injectable emulsion comprising: aprepitant; | Defendants' Proposed Product is an "injectable emulsion containing... aprepitant." | ¶41 | '208 Patent, col. 1:11-17 |
| 11 wt/wt % to 15 wt/wt % of an emulsifier; | The complaint alleges the product has the "same or equivalent ingredients in the same or equivalent amounts as the compositions claimed." | ¶42 | '208 Patent, claim 1 |
| an oil; | The product is an "injectable emulsion." | ¶41 | '208 Patent, col. 2:38-44 |
| a co-emulsifier which is an alcohol; | The complaint alleges the product has "same or equivalent ingredients." | ¶42 | '208 Patent, claim 1 |
| a tonicity modifier; a pH modifier; and water; | The product is alleged to be "substantially the same as Cinvanti®," which embodies the claims and contains these components. | ¶42 | '208 Patent, claim 1 |
| wherein the pH of the emulsion ranges from about 7.5 to 9.0 | The product is alleged to have the "same or substantially the same indications as Cinvanti®," implying a formulation with a similar pH necessary for those uses. | ¶43 | '208 Patent, claim 1 |
| wherein the emulsion is physically stable. | The complaint alleges the proposed product "performs substantially the same function, in substantially the same way, to achieve substantially the same result" as Cinvanti®, a stable emulsion. | ¶42 | '208 Patent, col. 8:8-12 |
'465 Patent Infringement Allegations
(Based on Claim 1 of representative '800 Patent)
| Claim Element (from Independent Claim 1) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| A method for preventing post-operative nausea and vomiting... | Defendants' product is alleged to have the "same or substantially the same indications as Cinvanti®," which is used for preventing nausea and vomiting. | ¶43 | '800 Patent, col. 9:1-5 |
| comprising intravenously administering an injectable pharmaceutical emulsion | The proposed product is an "injectable emulsion" intended for the same uses as Cinvanti®. | ¶41; Compl. ¶43 | '800 Patent, claim 1 |
| wherein the emulsion comprises: aprepitant; an emulsifier; an oil; a co-surfactant which is an alcohol; a tonicity agent; a pH modifier; and water | The complaint alleges the proposed product has the "same or equivalent ingredients" as the claimed compositions. | ¶42 | '800 Patent, claim 1 |
| wherein the ratio of the emulsifier to aprepitant ranges from about 18:1 to 22:1 (wt/wt %) | The complaint alleges the product has the "same or equivalent ingredients in the same or equivalent amounts." | ¶42 | '800 Patent, claim 1 |
- Identified Points of Contention:
- Scope Questions: The complaint does not specify the exact formulation of the Defendants' Proposed Product. A central point of contention will be whether the weight percentages and ratios of the components in the accused product (e.g., emulsifier, oil) fall within the specific ranges recited in the asserted claims. For example, a question for the court will be: What evidence demonstrates that the amount of "emulsifier" in the Defendants' product is within the "11 wt/wt% to 15 wt/wt%" range required by Claim 1 of the '208 Patent?
- Technical Questions: A key technical question will relate to the functional limitation of "physically stable" present in many claims. The patents define this term with reference to specific USP standards and the absence of visible crystals '208 Patent, col. 8:8-23 The infringement analysis may turn on whether Defendants' formulation, even if chemically similar, meets this specific, multi-part definition of stability over its shelf life, or whether it exhibits properties (e.g., crystal formation, particle size changes) that place it outside the claim scope.
V. Key Claim Terms for Construction
The Term: "physically stable"
Context and Importance: This term is a functional limitation that appears in composition claims (e.g.,'208 Patent, claim 1) and is critical for distinguishing the patented invention from prior art or other formulations. The entire dispute could hinge on whether Defendants' product meets this specific definition of stability, as a non-stable emulsion would not infringe. Practitioners may focus on this term because stability is a core technical challenge the patent purports to solve.
Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The complaint does not provide sufficient detail for analysis of evidence for a broader interpretation. A party might argue for a general commercial-level stability standard if not for the patent's specific definition.
- Evidence for a Narrower Interpretation: The specification provides a very explicit and narrow definition, stating that ""Physically stable" emulsions will meet the criteria under USP <729>...and...will have no visible aprepitant crystals upon storage" '208 Patent, col. 8:8-16 This ties the term directly to an external, objective standard (USP <729>) and a measurable outcome (no crystals), which strongly supports a narrow and specific construction.
The Term: "emulsifier"
Context and Importance: The type and amount of emulsifier are fundamental to creating a stable emulsion. The asserted claims recite specific weight percentage ranges for the emulsifier. A dispute may arise over whether the substance used by Defendants qualifies as the claimed "emulsifier" and if its concentration falls within the claimed range.
Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The specification provides a general definition: "An 'emulsifier' refers to a compound that deters the separation of the injectable emulsion into individual oil and aqueous phases" '208 Patent, col. 8:56-58 This broad functional definition could be used to argue that a variety of substances qualify.
- Evidence for a Narrower Interpretation: The specification consistently uses phospholipids, and specifically egg lecithin, in its examples and preferred embodiments ('208 Patent, col. 9:43-48; '208 Patent, Example 1). A party could argue that the term should be construed more narrowly to be limited to the types of phospholipids disclosed, such as egg lecithin.
VI. Other Allegations
- Indirect Infringement: The complaint alleges inducement and contributory infringement based on the grounds that Defendants' proposed product labeling will instruct medical professionals to administer the drug for the same indications as Cinvanti®, thereby causing them to directly infringe the asserted method-of-use patents Compl. ¶43 Compl. ¶52
- Willful Infringement: Willfulness is alleged based on Defendants' knowledge of the patents-in-suit, evidenced by their filing of an NDA with a Paragraph IV certification and the subsequent sending of a notice letter to Heron Compl. ¶44 Compl. ¶45 Compl. ¶56 This alleges pre-suit knowledge of the patents and of the infringing nature of their actions.
VII. Analyst's Conclusion: Key Questions for the Case
- A central issue will be one of claim validity, particularly concerning the written description requirement under 35 U.S.C. § 112. Given that a court has already invalidated claims in two related patents-in-suit for lacking adequate written description, a primary question will be whether the specifications of the remaining patents provide sufficient detail to support the breadth of the asserted claims, or if they suffer from the same potential defect.
- A key evidentiary question will be one of formulation equivalence. The case will likely depend on detailed evidence, to be produced during discovery, establishing the precise composition of the Defendants' Proposed Product. The analysis will focus on whether the specific weight percentages and ratios of its components, such as the emulsifier and oil, fall squarely within the ranges defined by the asserted claims.
- A third significant question will be one of functional performance: does the Defendants' generic product meet the specific definition of "physically stable" as required by the claims and defined in the patent specification? This will involve technical analysis comparing the stability profile of the accused product against the patent's explicit criteria, including compliance with USP <729> standards and the absence of crystal formation over time.