DCT
2:25-cv-15399
Supernus Pharma Inc v. Macleods Pharma Ltd
I. Executive Summary and Procedural Information
- Parties & Counsel:
- Plaintiff: Supernus Pharmaceuticals, Inc. (Delaware)
- Defendant: Macleods Pharmaceuticals Ltd. (India) and Macleods Pharma USA, Inc. (Delaware)
- Plaintiff’s Counsel: Saul Ewing LLP; Haug Partners LLP
- Case Identification: 2:25-cv-15399, D.N.J., 09/09/2025
- Venue Allegations: Plaintiff alleges venue is proper in the District of New Jersey because Defendant Macleods Pharma USA, Inc. maintains its principal place of business in Princeton, New Jersey, and both defendants are alleged to conduct substantial business in the state.
- Core Dispute: Plaintiff alleges that Defendants' filing of an Abbreviated New Drug Application (ANDA) seeking FDA approval to market generic versions of Plaintiff's Qelbree® (viloxazine) extended-release capsules constitutes an act of infringement of seven patents covering drug formulations and methods of treatment for Attention Deficit Hyperactivity Disorder (ADHD).
- Technical Context: The technology concerns extended-release pharmaceutical formulations designed to provide controlled delivery of viloxazine over a prolonged period, which is relevant for managing chronic conditions like ADHD by improving patient compliance and stabilizing drug plasma levels.
- Key Procedural History: The litigation was initiated under the Hatch-Waxman Act following Defendants' submission of ANDA No. 220570 and issuance of a Paragraph IV certification notice letter to Plaintiff on or about August 1, 2025. Plaintiff's counsel has also certified that the patents and drug product at issue are the subject of other pending litigation against different generic pharmaceutical manufacturers in both the District of New Jersey and the District of Delaware, suggesting a broad enforcement strategy for the Qelbree® patent portfolio.
Case Timeline
| Date | Event |
|---|---|
| 2008-09-05 | Earliest Priority Date (’753, ’143, ’523 Patents) |
| 2011-01-01 | Macleods Pharma USA, Inc. business operations commenced in the U.S. |
| 2012-02-08 | Earliest Priority Date (’204, ’853, ’338 Patents) |
| 2016-06-07 | ’204 Patent Issued |
| 2017-03-28 | ’853 Patent Issued |
| 2017-05-30 | ’338 Patent Issued |
| 2022-05-10 | ’753 Patent Issued |
| 2022-10-04 | ’143 Patent Issued |
| 2024-10-22 | ’523 Patent Issued |
| 2025-08-01 | Defendants sent Paragraph IV Notice Letter to Plaintiff |
| 2025-09-09 | Complaint Filed |
II. Technology and Patent(s)-in-Suit Analysis
U.S. Patent No. 9,358,204 - "Formulations of Viloxazine"
The Invention Explained
- Problem Addressed: The patent's background section notes that viloxazine presents challenges for developing an extended-release formulation due to its potentially high therapeutic dose, weakly basic nature, and relatively high in vivo clearance rate in humans (’204 Patent, col. 1:49-59).
- The Patented Solution: The invention provides modified-release oral dosage formulations of viloxazine that allow for once or twice-daily administration. The solution involves using release-rate controlling compounds, such as hydrophilic or hydrophobic polymers, to create either a drug-containing matrix or a multi-layered particle system that releases the drug over an extended period, thereby overcoming the pharmacokinetic challenges of the active ingredient (’204 Patent, Abstract; col. 2:3-13).
- Technical Importance: An extended-release formulation for a drug treating a chronic condition like ADHD can improve patient adherence to the treatment regimen and may reduce side effects by maintaining more stable plasma concentrations compared to multiple daily doses of an immediate-release version (’204 Patent, col. 3:24-40).
Key Claims at a Glance
The complaint does not identify specific asserted claims. Claim 1, an independent claim, is representative of the formulation technology.
- A pharmaceutical formulation comprising:
- an immediate release (IR) component comprising an inert core and a layer comprising viloxazine; and
- an extended release (XR) component comprising: (i) an inert core, (ii) a first layer comprising viloxazine surrounding the core, and (iii) a second layer comprising a release rate controlling compound and a pore former surrounding the first layer.
The complaint does not explicitly reserve the right to assert dependent claims, but infringement is alleged for "one or more claims" of each patent (Compl. ¶68).
U.S. Patent No. 9,603,853 - "Formulations of Viloxazine"
The Invention Explained
- Problem Addressed: As a divisional of the application leading to the ’204 Patent, this patent addresses the same challenges of formulating viloxazine for extended release due to its pharmacokinetic properties (’853 Patent, col. 1:53-63).
- The Patented Solution: The patent claims methods of treating ADHD or major depressive disorder by administering a specific extended-release formulation of viloxazine. The claimed formulation combines immediate-release and extended-release components to achieve a therapeutic effect with once or twice-daily dosing, which can reduce side effects such as dyspepsia, nausea, and sleep disturbances compared to immediate-release formulations (’853 Patent, Abstract; col. 3:21-41).
- Technical Importance: By claiming a method of treatment using a specific formulation type, the invention aims to protect not just the drug product itself but also its particular manner of use for achieving a therapeutic benefit with an improved side-effect profile.
Key Claims at a Glance
The complaint does not identify specific asserted claims. Claim 1, an independent claim, is representative of the patented method.
- A method for treating ADHD or major depressive disorder in a mammalian subject, comprising administering a formulation that includes:
- an immediate release (IR) component with an inert core and a viloxazine layer; and
- an extended release (XR) component with (i) an inert core, (ii) a first viloxazine layer, and (iii) a second layer with a release rate controlling compound and a pore former.
The complaint does not explicitly reserve the right to assert dependent claims, but infringement is alleged for "one or more claims" of each patent (Compl. ¶90).
U.S. Patent No. 9,662,338 - "Formulations of Viloxazine"
- Technology Synopsis: This patent, from the same family as the ’204 and ’853 patents, also describes extended-release formulations of viloxazine. It is directed to pharmaceutical compositions comprising an extended-release component with a specific layered structure, including a release rate controlling compound and a pore former, to modulate drug delivery (’338 Patent, col. 26:30-51).
- Asserted Claims: The complaint does not specify claims; Claim 1 is an independent composition claim.
- Accused Features: The formulation of Defendants' proposed generic viloxazine extended-release capsules is alleged to infringe (Compl. ¶112).
U.S. Patent No. 11,324,753 - "Method of Treatment of Attention Deficit/Hyperactivity Disorder (ADHD)"
- Technology Synopsis: This patent describes a method for treating ADHD based on the asserted discovery that viloxazine exhibits antagonist activity at specific serotonin receptors (5-HT7 and 5HT1B) (’753 Patent, col. 1:29-33, col. 2:27-33). The invention is for a method of treating ADHD by administering viloxazine to achieve this antagonism.
- Asserted Claims: The complaint does not specify claims; Claim 1 is an independent method claim.
- Accused Features: The proposed labeling for Defendants' ANDA product, which indicates the product for the treatment of ADHD, is alleged to induce infringement of this method (Compl. ¶¶57, 134).
U.S. Patent No. 11,458,143 - "Method of Treatment of Attention Deficit/Hyperactivity Disorder (ADHD)"
- Technology Synopsis: This patent, from the same family as the ’753 patent, is also directed to a method for treating ADHD by administering viloxazine. The claims focus on the administration of a formulation of viloxazine to a patient suffering from ADHD (’143 Patent, Abstract).
- Asserted Claims: The complaint does not specify claims; Claim 1 is an independent method claim.
- Accused Features: The proposed labeling for Defendants' ANDA product, which indicates the product for the treatment of ADHD, is alleged to induce infringement (Compl. ¶¶57, 156).
U.S. Patent No. 12,121,523 - "Method of Treatment of Attention Deficit/Hyperactivity Disorder (ADHD)"
- Technology Synopsis: This patent, also from the same family as the ’753 and ’143 patents, covers methods of treating ADHD and co-morbid mood or affective disorders by administering viloxazine. The invention is predicated on viloxazine's specific receptor activities (’523 Patent, col. 2:22-34).
- Asserted Claims: The complaint does not specify claims; Claim 1 is an independent method claim.
- Accused Features: The proposed labeling indicating the product for treatment of ADHD is alleged to induce infringement (Compl. ¶¶57, 178).
III. The Accused Instrumentality
Product Identification
- Defendants' proposed generic drugs, identified as "Defendants' ANDA Products," are viloxazine extended-release oral capsules in 150 mg and 200 mg dosages (Compl. ¶15).
Functionality and Market Context
- The complaint alleges that the ANDA Products are generic versions of Plaintiff's branded drug, Qelbree®, and that Defendants have represented to the FDA that their products are bioequivalent to Qelbree® (Compl. ¶¶52, 54). The proposed prescribing information allegedly states that the ANDA Products are "indicated for the treatment of Attention-Deficit Hyperactivity Disorder (ADHD) in adults and pediatric patients 6 years and older" and contains recommended dosage and administration instructions that substantially mirror those for Qelbree® (Compl. ¶¶57-58).
IV. Analysis of Infringement Allegations
No probative visual evidence provided in complaint. The complaint makes general allegations of infringement without referencing specific claims or providing claim charts. The following charts are based on representative independent claims and the infringement theories implied in the complaint.
U.S. Patent No. 9,358,204 Infringement Allegations
| Claim Element (from Independent Claim 1) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| a pharmaceutical formulation, comprising: (a) an immediate release (IR) component... and (b) an extended release (XR) component | The ANDA product is alleged to be an extended-release viloxazine capsule formulation. | ¶15 | col. 2:3-8 |
| the IR component comprising an inert core and a layer comprising viloxazine... surrounding the core | The complaint alleges the ANDA product is a bioequivalent copy of Qelbree®, thereby implying it contains the claimed IR structural components. | ¶54 | col. 9:1-5 |
| the XR component comprising: (i) an inert core, (ii) a first layer comprising viloxazine... surrounding the core, and (iii) a second layer... surrounding the first layer | The complaint alleges the ANDA product is a bioequivalent copy of Qelbree®, thereby implying it contains the claimed XR structural components. | ¶54 | col. 7:47-66 |
| the second layer comprising a release rate controlling compound and a pore former | The complaint does not provide specific details on the excipients in the ANDA product but implies its formulation infringes. | ¶74 | col. 26:1-20 |
U.S. Patent No. 9,603,853 Infringement Allegations
| Claim Element (from Independent Claim 1) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| A method for treating a condition selected from the group consisting of ADHD and major depressive disorder in a mammalian subject | Defendants' proposed product label is alleged to state the product is "indicated for the treatment of Attention-Deficit Hyperactivity Disorder (ADHD)." | ¶57 | col. 3:24-30 |
| comprising administration to the subject of a formulation comprising: (a) an immediate release (IR) component... and (b) an extended release (XR) component | The proposed label allegedly instructs administration of an extended-release capsule formulation for treating ADHD. | ¶¶15, 58 | col. 2:3-8 |
| wherein the formulation provides for a maximum steady state plasma concentration... of 50% to 125% relative to the maximum plasma concentration produced by administration of viloxazine as an IR formulation | Defendants allegedly represented to the FDA that their product is bioequivalent to the reference listed drug, Qelbree®, implying it will produce a similar pharmacokinetic profile. | ¶54 | col. 3:41-48 |
Identified Points of Contention
- Scope Questions: A central question for the formulation patents (’204, ’853, ’338) will be whether the term "component," in the context of distinct IR and XR populations of particles, can be construed to read on a formulation that may use a different technological approach (e.g., a single population of particles with a multi-phasic release profile or a monolithic matrix tablet). For the method patents (’753, ’143, ’523), a key issue may be whether claiming a "method of treating ADHD" by administering a known drug is distinct from the prior art, particularly where later patents add limitations concerning newly discovered mechanisms of action.
- Technical Questions: The primary technical question is factual and currently unanswered by the complaint: What is the specific composition, structure, and release mechanism of Defendants' ANDA product? The infringement analysis for the formulation patents hinges entirely on whether the generic product contains the specifically claimed layered structures with pore formers, as opposed to achieving extended release via a non-infringing design.
V. Key Claim Terms for Construction
Term: "a second layer comprising a release rate controlling compound and a pore former... surrounding the first layer" (from Claim 1 of the ’204 Patent)
- Context and Importance: This term defines the core structural and compositional basis for the extended-release mechanism in several key claims. Practitioners may focus on this term because a defendant could argue its product achieves extended release through a fundamentally different, non-infringing design, such as a monolithic matrix where the drug and polymer are homogeneously mixed rather than arranged in discrete, surrounding layers.
- Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The specification describes various systems, including "Matrix systems" and "Drug-layered systems," suggesting the invention is not strictly limited to one physical arrangement, which could support a broader reading of how the components are organized (’204 Patent, col. 7:30-56).
- Evidence for a Narrower Interpretation: The claim language itself, requiring a "first layer... surrounding the core" and a "second layer... surrounding the first layer," suggests a specific, concentric, multi-particulate structure. The detailed description of drug-layered systems reinforces this structural limitation, which a defendant may argue is not met by a different formulation type (’204 Patent, col. 8:48-51).
Term: "an immediate release (IR) component" and "an extended release (XR) component" (from Claim 1 of the ’853 Patent)
- Context and Importance: The claims require the presence of two distinct "components." The definition of what qualifies as "IR" versus "XR" and whether a single dosage form can be said to contain two separate "components" will be critical. A defendant might argue its product is a single, integrated XR system with an initial burst release, rather than a combination of two structurally distinct populations of particles.
- Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The specification discusses achieving pulsatile release through various combinations, including an "IR component with an extended release (XR) component" (’853 Patent, col. 2:10-13), which could be interpreted functionally rather than purely structurally.
- Evidence for a Narrower Interpretation: The patent explicitly defines "immediate release" as releasing ≥80% of the agent in ≤1 hour and "extended release" as releasing ≥80% over at least 2 hours (’853 Patent, col. 5:36-52). These quantitative definitions provide clear boundaries that a defendant's product may be argued to fall outside of, or a defendant may argue their single-component formulation does not meet both definitions simultaneously.
VI. Other Allegations
Indirect Infringement
- The complaint alleges induced infringement for all asserted patents. The primary basis is the allegation that Defendants' proposed product labeling will instruct physicians and patients to administer the ANDA product for the treatment of ADHD, thereby directing them to perform the steps of the asserted method-of-use claims (Compl. ¶¶99-102, 121-124, 143-146, 165-168, 187-190). Contributory infringement is also alleged on the basis that the ANDA product is a material part of the patented inventions and is not a staple article of commerce suitable for substantial non-infringing uses (Compl. ¶¶81, 103, 125, 147, 169, 191).
Willful Infringement
- The complaint alleges willful infringement based on Defendants' knowledge of the patents-in-suit, as evidenced by their filing of a Paragraph IV certification that specifically identified each patent (Compl. ¶¶82, 104, 126, 148, 170, 192).
VII. Analyst’s Conclusion: Key Questions for the Case
- A core issue will be one of structural infringement: Does the defendants' generic formulation, the technical details of which are not yet public, embody the specific multi-layered particle structure recited in the formulation patents (’204, ’853, ’338), or does it achieve a bioequivalent extended-release profile through a different, non-infringing design such as a monolithic matrix system?
- A second key issue for the later-issued method-of-use patents (’753, ’143, ’523) will be validity: Are the claims directed to methods of treating ADHD with viloxazine, an active ingredient previously used for depression, patentably distinct over the prior art, particularly where the claims may rely on a newly characterized mechanism of action for a known therapeutic outcome?
- Finally, a central question of induced infringement will turn on the content of the defendants' product label. Assuming the label mirrors that of the brand-name drug by indicating the product for ADHD treatment, the court will need to determine if that instruction is sufficient to induce infringement of method claims that may contain additional limitations, such as achieving a specific pharmacokinetic profile or acting via a particular biological mechanism.