Supernus v. Aurobindo: Six-Patent Qelbree Suit Voluntarily Dismissed in 91 Days
Supernus Pharmaceuticals filed suit in the Delaware District Court asserting six patents covering its ADHD drug Qelbree (viloxazine extended-release capsules) against Indian generic manufacturer Aurobindo Pharma. The case resolved in just 91 days when Supernus voluntarily dismissed without prejudice under Rule 41(a), leaving future enforcement options open.
A Six-Patent ANDA Battle Over Qelbree Ends Before It Begins
On July 1, 2025, Supernus Pharmaceuticals, Inc. filed suit in the U.S. District Court for the District of Delaware against Aurobindo Pharma, Ltd. and Aurobindo Pharma U.S.A., Inc., asserting six U.S. patents directed to viloxazine extended-release formulations and methods of use — the active technology underlying Qelbree, Supernus’s FDA-approved ADHD treatment available in 100 mg, 150 mg, and 200 mg capsule strengths. The asserted patents span application numbers filed between 2013 and 2022, reflecting a layered IP strategy built around the Qelbree franchise.
The case ended on September 30, 2025 — just 91 days after filing — when Supernus filed a notice of voluntary dismissal without prejudice pursuant to Federal Rule of Civil Procedure 41(a). A dismissal without prejudice means no merits adjudication occurred: the claims were not decided, no infringement finding was made, and no invalidity determination was reached. Critically, Supernus retains the right to refile the same claims against Aurobindo at a later date, subject to applicable statutes of limitations.
A 91-day resolution is notably swift for a multi-patent pharmaceutical infringement action in Delaware, suggesting the parties may have reached a licensing arrangement, consent judgment, or other commercial understanding outside the public record — though the filing itself is silent on the reason for dismissal. The absence of defendant law firm information and the voluntary nature of the exit are consistent with a negotiated outcome, but this cannot be confirmed from the docket alone. The case’s resolution leaves Supernus’s six Qelbree patents unlitigated and enforceable.
Filing to Voluntary dismissal in 91 days
91 days — resolved significantly faster than the median Delaware patent case (typically 2–3 years to trial)
Voluntarily dismissed: what Rule 41(a) means for both parties
Rule 41(a) voluntary dismissal: no merits, door left open
Under Federal Rule of Civil Procedure 41(a), a plaintiff may dismiss its complaint without a court order before the defendant serves an answer or motion for summary judgment. This dismissal is ‘without prejudice,’ meaning the lawsuit is withdrawn without any determination on the merits. Supernus’s six patent claims against Aurobindo were never adjudicated — no court found infringement or invalidity.
No merits rulingWithout prejudice: the distinction matters significantly
A dismissal ‘with prejudice’ would permanently bar Supernus from suing Aurobindo again on the same claims. A dismissal ‘without prejudice’ preserves Supernus’s right to refile. The verdict text here explicitly states ‘without prejudice,’ so the public record is unambiguous on this point. Whether Supernus will refile — or whether a private settlement or licensing agreement has resolved the underlying commercial dispute — is not disclosed in the docket.
Refiling right preservedAurobindo faces no injunction — but ongoing patent risk remains
Aurobindo obtained a dismissal without any adverse finding, but gains no legal clearance to launch a generic viloxazine ER product. No invalidity ruling was made, and all six Supernus patents remain in force. Aurobindo’s ANDA pathway to the U.S. market for viloxazine ER capsules remains legally encumbered by the Supernus patent portfolio, which could be reasserted at any time.
No clearance grantedSwift exit suggests an off-docket resolution in the Qelbree market
A 91-day voluntary dismissal in a six-patent pharmaceutical case in Delaware is atypical and consistent with parties reaching a commercial agreement — such as a licensing deal, consent judgment, or market entry date agreement — outside the public record. For the broader viloxazine ER generic market, this outcome may signal that Supernus is actively managing its patent lifecycle through negotiated settlements rather than protracted litigation.
Likely off-docket resolutionFull party and counsel information
| Role | Name | Type | Detail |
|---|---|---|---|
| Plaintiff | Supernus Pharmaceuticals, Inc. | Company | Specialty CNS pharmaceutical company — holder of US12121523B2 and five further Qelbree patentsSearch in Eureka ↗ |
| Defendant | Aurobindo Pharma, Ltd. | Company | Indian generic pharmaceutical manufacturer with a U.S. subsidiary targeting the ADHD drug marketSearch in Eureka ↗ |
| Plaintiff counsel | Edgar H. Haug | Attorney | Counsel for Supernus Pharmaceuticals, Inc.Search in Eureka ↗ |
| Plaintiff counsel | Francis DiGiovanni | Attorney | Counsel for Supernus Pharmaceuticals, Inc.Search in Eureka ↗ |
| Plaintiff counsel | Nicholas F. Giove | Attorney | Counsel for Supernus Pharmaceuticals, Inc.Search in Eureka ↗ |
| Plaintiff counsel | Thatcher A. Rahmeier | Attorney | Counsel for Supernus Pharmaceuticals, Inc.Search in Eureka ↗ |
| Plaintiff law firm | Faegre Drinker Biddle & Reath LLP | Law Firm | Representing Supernus Pharmaceuticals, Inc.Search in Eureka ↗ |
| Presiding judge | Judge Jennifer L. Hall | Judge | Delaware District CourtSearch in Eureka ↗ |
Official order — verbatim text
The dismissal notice invokes Rule 41(a) and explicitly specifies ‘without prejudice,’ which is the operative legal language. This formulation confirms that no court-sanctioned merits ruling was issued — no claims were construed, no infringement was found, and no patent was invalidated. For Supernus, the six asserted patents remain intact and fully enforceable. For Aurobindo, the dismissal provides procedural relief but zero legal clearance. The public record does not disclose any settlement terms, licensing arrangement, or agreed market entry date that may underlie this exit.
US12121523B2 and five further patents — Qelbree viloxazine ER formulations
The six patents asserted in this case — US12121523B2, US11324753B2, US9358204B2, US11458143B2, US9603853B2, and US9662338B2 — collectively cover the formulation, composition, and methods of use of viloxazine in an extended-release oral capsule format, marketed as Qelbree. The application filings span from 2013 (US13/761757) through 2022 (US17/896774), reflecting a prosecution strategy designed to maintain patent coverage as the product matured. Viloxazine is a selective norepinephrine reuptake inhibitor approved for pediatric and adult ADHD.
The breadth of this six-patent portfolio — covering formulation, dosage strength, and method claims across multiple application generations — represents a deliberate effort to create overlapping exclusivity for Qelbree beyond any single patent’s expiry. For generic competitors pursuing an ANDA, this means Paragraph IV certifications must address each patent independently, raising the cost and complexity of any challenge. Competitors in the CNS/ADHD pharmaceutical space should treat this patent family as a high-priority landscape monitoring target given Qelbree’s commercial significance.
Should you run an FTO against the six Qelbree patents?
Any company developing, manufacturing, or seeking regulatory approval for a viloxazine extended-release oral capsule product — including 100 mg, 150 mg, and 200 mg dosage strengths — should conduct a freedom-to-operate analysis against all six patents asserted in this case. This case’s voluntary dismissal without prejudice means no invalidity finding was made, and all six patents remain fully in force. ANDA filers, 505(b)(2) applicants, and international manufacturers entering the U.S. market face material infringement risk without a formal FTO assessment.
PatSnap Eureka’s FTO Search Agent can rapidly map claim scope across all six Qelbree patents, identify relevant prior art, and flag design-around opportunities in the viloxazine ER formulation space. R&D and regulatory teams can use Eureka to model which claims pose the highest litigation risk based on Supernus’s enforcement history and claim language, helping prioritise which patents require the deepest invalidity analysis before any launch decision.
Run a freedom-to-operate analysis on US12121523B2 to assess your product’s exposure
Run FTO in Eureka →Similar ANDA patent cases involving CNS drug formulations in Delaware
Explore comparable pharmaceutical patent infringement actions involving extended-release CNS drug formulations litigated in the Delaware District Court.
What this case signals for the CNS pharmaceutical IP landscape
Supernus’s six-patent Qelbree enforcement strategy and swift voluntary exit offer a revealing window into ANDA litigation tactics for branded CNS drugs.
Layered patent portfolios remain the primary ANDA defense tool for CNS drugs
Supernus asserted six patents spanning nearly a decade of application filings against a single generic entrant. This stacking strategy — covering formulations, dosages, and methods — creates multiple invalidity hurdles for ANDA filers and signals that branded CNS companies are building dense patent thickets around blockbuster drugs like Qelbree.
Early voluntary dismissals in Delaware often mask commercial settlements
When a plaintiff drops a multi-patent pharmaceutical suit in under 100 days without prejudice, it typically signals a negotiated outcome rather than a litigation failure. IP teams monitoring Qelbree’s generic entry timeline should watch for any Paragraph IV certification activity or subsequent refiling by Supernus against Aurobindo or other ANDA filers.
Supernus v Aurobindo — key questions answered
Supernus Pharmaceuticals filed suit against Aurobindo Pharma in Delaware on July 1, 2025, asserting six patents covering Qelbree (viloxazine extended-release capsules). On September 30, 2025 — 91 days later — Supernus voluntarily dismissed the complaint without prejudice under Rule 41(a). No merits determination was made; all six patents remain enforceable.
A dismissal without prejudice means Supernus withdrew its complaint without any court ruling on infringement or patent validity. Supernus retains the right to refile the same claims against Aurobindo in the future. Aurobindo received no invalidity finding and no legal clearance to launch a generic viloxazine ER product. The six asserted Qelbree patents remain in full force.
Supernus asserted six patents: US12121523B2, US11324753B2, US9358204B2, US11458143B2, US9603853B2, and US9662338B2. These patents cover viloxazine extended-release formulations, compositions, and methods of use across 100 mg, 150 mg, and 200 mg dosage strengths. Application filings date from 2013 through 2022, forming a layered IP portfolio around the Qelbree franchise.
The public record does not disclose the reason for dismissal. However, a 91-day voluntary dismissal in a six-patent pharmaceutical ANDA case in Delaware is atypical and is consistent with the parties reaching a private settlement, licensing agreement, or consent judgment. This cannot be confirmed from the docket alone, and no such agreement has been filed publicly.
No. The dismissal without prejudice confers no legal clearance on Aurobindo. All six Supernus patents covering viloxazine extended-release formulations remain enforceable. Aurobindo would still need to successfully challenge or design around all six patents before any U.S. market launch. Supernus also retains the right to refile suit at any time within the applicable limitations period.
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