Axsome Malta v. Hikma Pharmaceuticals: Solriamfetol Patent Suit Dismissed Without Prejudice
Axsome Malta filed suit against Hikma Pharmaceuticals USA in the District of New Jersey, asserting two patents covering solriamfetol oral tablets marketed as Sunosi®. All claims and counterclaims were dismissed without prejudice by stipulation under Rule 41(a)(1)(A)(ii) after just 111 days — leaving the door open for future litigation.
Solriamfetol ANDA Battle Ends Early, Terms Undisclosed
On November 20, 2024, Axsome Malta, Ltd. filed a patent infringement action against Hikma Pharmaceuticals USA, Inc. in the U.S. District Court for the District of New Jersey (Case No. 2:24-cv-10620). The suit was triggered by Hikma’s ANDA filing for generic solriamfetol oral tablets — the active ingredient in Axsome’s Sunosi®, approved for excessive daytime sleepiness in narcolepsy and obstructive sleep apnea. Two patents were asserted: US12090126B2 and US12102609B2, both tied to solriamfetol formulations at 75 mg and 150 mg base equivalents.
The case closed on March 11, 2025, just 111 days after filing, via a joint stipulation of dismissal without prejudice under Federal Rule of Civil Procedure 41(a)(1)(A)(ii). All claims, counterclaims, and affirmative defenses were dropped by mutual agreement, with each party absorbing its own legal costs. A dismissal without prejudice means the action is terminated on the merits but Axsome is not barred from re-asserting the same patents against Hikma in a future proceeding.
The 111-day timeline is notably brief for pharmaceutical patent litigation, consistent with either an out-of-court licensing agreement, a consent judgment governing Hikma’s market entry date, or simply a strategic reset. The public record is silent on the underlying commercial terms, if any. Whether the resolution reflects a settlement with a negotiated entry date — a common outcome in Hatch-Waxman disputes — or a purely procedural pause ahead of re-filing remains unknown from docket filings alone.
Filing to Dismissed without Prejudice in 111 days
111 days — significantly shorter than the median ANDA patent case, suggesting early resolution before substantive motions practice
Dismissed without prejudice: what the stipulation means for both parties
Rule 41(a)(1)(A)(ii) — Stipulated dismissal, not a merits ruling
A dismissal under Federal Rule of Civil Procedure 41(a)(1)(A)(ii) requires the signed agreement of all parties. It is a procedural exit — no court adjudicated the validity or infringement of US12090126B2 or US12102609B2. The ‘without prejudice’ designation means the action is terminated without any preclusive effect, leaving both parties’ legal positions exactly where they were before the suit was filed.
No merits adjudicationWithout prejudice: re-filing remains an option for Axsome
A dismissal without prejudice does not extinguish the underlying patent claims. Axsome Malta retains the full right to re-assert US12090126B2 and US12102609B2 against Hikma — or any other ANDA filer — in a future action. This is categorically different from a dismissal with prejudice, which would bar re-litigation. The public docket does not disclose whether a licensing agreement or consent decree governs Hikma’s launch rights; those terms, if they exist, are private.
Axsome may re-fileHikma faces no injunction, but patent risk persists
Hikma obtained no court ruling confirming non-infringement or invalidity of the asserted patents. If a private settlement was reached, it may include negotiated launch timing for Hikma’s generic solriamfetol tablets. Without a consent judgment on the public record, Hikma’s freedom to commercially launch remains subject to the at-risk launch analysis it must independently conduct. Any launch before patent expiry carries litigation re-exposure given the without-prejudice posture.
No infringement rulingHatch-Waxman resolution pattern: private terms shape generic timelines
In ANDA litigation, stipulated dismissals without prejudice frequently signal a confidential settlement that determines when a generic may enter the market. For solriamfetol competitors and formulary decision-makers, the absence of a public merits ruling means the patents retain their presumption of validity and enforceability. Other potential ANDA filers for solriamfetol should treat US12090126B2 and US12102609B2 as live enforcement risks requiring independent FTO clearance.
Patent risk remains liveFull party and counsel information
| Role | Name | Type | Detail |
|---|---|---|---|
| Plaintiff | Axsome Malta, Ltd. | Company | Pharmaceutical IP licensor — holder of US12090126B2 and US12102609B2 covering solriamfetol tabletsSearch in Eureka ↗ |
| Defendant | Hikma Pharmaceuticals USA, Inc. | Company | US generics subsidiary of Hikma Pharmaceuticals PLC seeking ANDA approval for solriamfetol tabletsSearch in Eureka ↗ |
| Plaintiff counsel | Alexander Lee Callo | Attorney | Counsel for Axsome Malta, Ltd.Search in Eureka ↗ |
| Plaintiff counsel | Charles Michael Lizza | Attorney | Counsel for Axsome Malta, Ltd.Search in Eureka ↗ |
| Plaintiff counsel | Sarah Ann Sullvian | Attorney | Counsel for Axsome Malta, Ltd.Search in Eureka ↗ |
| Plaintiff counsel | William C. Baton | Attorney | Counsel for Axsome Malta, Ltd.Search in Eureka ↗ |
| Plaintiff law firm | Saul Ewing LLP | Law Firm | Representing Axsome Malta, Ltd.Search in Eureka ↗ |
| Defendant counsel | James S. Richter | Attorney | Counsel for Hikma Pharmaceuticals USA, Inc.Search in Eureka ↗ |
| Defendant law firm | MIDLIGE RICHTER LLC | Law Firm | Representing Hikma Pharmaceuticals USA, Inc.Search in Eureka ↗ |
| Presiding judge | Judge N/A | Judge | New Jersey District CourtSearch in Eureka ↗ |
Official order — verbatim text
The stipulation’s language is precise and comprehensive: ‘all claims, counterclaims, and affirmative defenses’ are extinguished, ensuring neither party can argue that any issue was left unresolved or implicitly adjudicated. The explicit exclusion of costs and attorneys’ fees removes any financial precedent. Critically, the without-prejudice designation means Axsome’s infringement claims — and Hikma’s invalidity defences — survive in potential future proceedings, consistent with a negotiated resolution rather than a unilateral concession by either side.
US12090126B2 & US12102609B2 — Solriamfetol oral tablet formulations
US12090126B2 (application US18/491311) and US12102609B2 (application US18/491319) cover solriamfetol oral tablet formulations corresponding to Sunosi® at 75 mg and 150 mg base equivalents. Solriamfetol is a dopamine and norepinephrine reuptake inhibitor (DNRI) approved for treating excessive daytime sleepiness (EDS) associated with narcolepsy and obstructive sleep apnea. Both applications carry late-2023 filing dates, and the B2 grant status indicates these patents issued with granted claims following examination — not provisional placeholders — giving them meaningful remaining patent term extending well into the 2040s.
The strategic importance of these patents lies in their timing: granted as solriamfetol began attracting ANDA filers, they represent Axsome’s primary enforcement assets against generic entry into what remains a commercially significant CNS sleep disorder market. With two patents asserting different claim scopes across the same product, Axsome can deploy layered enforcement strategies against any ANDA challenger. Companies developing competing DNRI formulations or pursuing bioequivalence to Sunosi® face a real risk of being drawn into the same litigation framework Hikma encountered, regardless of the outcome of this particular dismissal.
Should your solriamfetol programme run FTO against US12090126B2 and US12102609B2?
Any pharmaceutical company, CMO, or formulation team working on solriamfetol oral tablets — whether for ANDA filing, 505(b)(2) development, or international market entry — should treat both US12090126B2 and US12102609B2 as live clearance risks. These patents have not been invalidated, disclaimed, or judicially construed. The scope of their claims against alternative tablet formulations, excipient combinations, or dosage strengths cannot be assumed away from this case’s dismissal without prejudice.
PatSnap Eureka’s FTO Search Agent can map the full claim scope of US12090126B2 and US12102609B2 against your proposed formulation, identify continuation applications filed in the same priority families, and surface any inter partes review or post-grant proceedings that could affect enforceability. Eureka also tracks Axsome’s broader portfolio for newly granted patents that could extend the exclusivity window beyond the currently asserted pair, giving R&D and legal teams early warning before ANDA filing triggers automatic infringement exposure.
Run a freedom-to-operate analysis on US12090126B2 to assess your product’s exposure
Run FTO in Eureka →Similar solriamfetol and CNS ANDA patent cases in the District of New Jersey
Cases involving Hatch-Waxman ANDA challenges to CNS sleep disorder drug patents in the District of New Jersey, with comparable dismissal or settlement patterns.
What this case signals for the solriamfetol and CNS generics IP landscape
A swift, silent exit in Hatch-Waxman litigation rarely means the dispute is truly over — it often marks the start of a private framework.
Without-prejudice dismissals in ANDA cases warrant monitoring for re-filing
When a branded pharmaceutical plaintiff dismisses without prejudice this quickly, the most commercially significant information — any agreed entry date for the generic — typically sits in a private agreement, not the docket. IP teams tracking the solriamfetol market should monitor for any subsequent NDA or ANDA correspondence and watch for re-filed actions against Hikma or new ANDA filers.
US12090126B2 and US12102609B2 retain full presumption of validity
No court invalidated, narrowed, or construed these patents. Any company developing a competing solriamfetol formulation — tablet, extended-release, or otherwise — should treat both patents as fully enforceable. The application numbers (US18/491311 and US18/491319) suggest these are relatively recent grants, potentially with meaningful remaining term that amplifies enforcement leverage.
Axsome v Hikma — key questions answered
The case was filed on November 20, 2024 in the District of New Jersey and closed on March 11, 2025 — 111 days later. Axsome Malta asserted US12090126B2 and US12102609B2 against Hikma’s ANDA for generic solriamfetol tablets. The parties filed a joint stipulation under Rule 41(a)(1)(A)(ii) dismissing all claims without prejudice and without costs to either party. No court ruled on the merits of infringement or patent validity.
A dismissal without prejudice means Axsome Malta retains the full right to re-file suit against Hikma — or any other party — asserting the same patents. Neither US12090126B2 nor US12102609B2 was invalidated or narrowed by this proceeding. The patents continue to carry a full presumption of validity, and Axsome’s enforcement position is legally unchanged by the dismissal.
Not necessarily. The dismissal is without prejudice, meaning Axsome could re-file. If a private settlement included a negotiated entry date for Hikma’s generic, that agreement is not publicly disclosed. Hikma would need to independently assess its freedom to launch at commercial risk, particularly given the live status of both asserted patents and the absence of any court-ordered consent judgment on the public docket.
Both are U.S. utility patents granted to Axsome covering solriamfetol oral tablet formulations — the active ingredient in Sunosi®, approved for excessive daytime sleepiness in narcolepsy and obstructive sleep apnea. The corresponding applications US18/491311 and US18/491319 were filed in late 2023, suggesting relatively recent grants with significant remaining patent term. They are the primary IP assets Axsome deployed against Hikma’s ANDA challenge.
While the public record does not disclose the reason, 111 days is unusually fast for Hatch-Waxman patent litigation, which typically extends years. This timeline is consistent with either a private settlement — potentially including a negotiated generic entry date — or a strategic decision by one or both parties to pause and re-evaluate. The mutual agreement to bear individual costs suggests neither party was compelled to capitulate; it is more likely a structured resolution than an abandonment of claims.
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