Otsuka & Lundbeck v. Mylan & Viatris: Aripiprazole Dosing Patent Dismissed Without Prejudice
Otsuka Pharmaceutical and H. Lundbeck pursued a patent infringement action against Mylan and its parent Viatris in Delaware over US11400087B2, a method patent governing aripiprazole delivery to patients with compromised CYP2D6 or CYP3A4 enzyme activity. The parties stipulated to dismissal without prejudice after 618 days, with each side bearing its own costs.
Hatch-Waxman dosing method dispute ends in confidential settlement
On 20 September 2022, Otsuka Pharmaceutical Co., Ltd. and H. Lundbeck AS filed a patent infringement action in the District of Delaware against Mylan NV, Mylan Pharmaceuticals Inc., and Viatris Inc. The action centred on US11400087B2 — a method patent covering the provision of aripiprazole to patients with impaired CYP2D6 or CYP3A4 enzyme function, a pharmacogenomics-sensitive dosing protocol relevant to the antipsychotic drug market. The case was assigned to Judge Jennifer L. Hall.
After 618 days of litigation, the parties filed a stipulated dismissal without prejudice on 30 May 2024. All remaining claims and counterclaims were dismissed, with each side bearing its own costs and attorneys’ fees. The Delaware District Court retained jurisdiction to adjudicate any issues arising from the settlement — a standard provision that signals the parties reached a private commercial agreement, most likely a consent-to-judgement arrangement or a negotiated ANDA entry date.
The 618-day duration suggests substantive engagement — likely including ANDA-related claim charts, Markman preparation, and settlement negotiations — before the parties reached agreement. The without-prejudice nature of the dismissal leaves the patent’s validity and infringement questions unanswered in the public record, which may be strategically advantageous for Otsuka and Lundbeck if further generic entrants challenge the same patent. The precise commercial terms of any underlying settlement remain undisclosed.
Filing to Dismissed without Prejudice in 618 days
618 days — longer than median ANDA Hatch-Waxman first instance case in Delaware
Dismissed without prejudice: what the stipulated exit means for both sides
Stipulated dismissal without prejudice preserves future options
A dismissal without prejudice means no adjudication on the merits occurred. Otsuka and Lundbeck retain the right to re-file claims on US11400087B2 against Mylan or Viatris in a future action, subject to applicable statutes of limitations. Crucially, the court specifically retained jurisdiction to resolve any disputes arising from the underlying settlement — suggesting a negotiated agreement was reached even if its terms remain confidential.
No merits ruling — re-filing possibleOtsuka and Lundbeck keep enforcement rights intact
Because the dismissal is without prejudice, US11400087B2 remains unchallenged on the merits in this proceeding. Otsuka and Lundbeck are not estopped from asserting the patent again. The retained jurisdiction clause suggests the settlement includes ongoing obligations — potentially a licence, delayed entry date, or other commercial terms — giving the patent holders continued commercial protection for the aripiprazole dosing method.
Patent survives — enforcement intactMylan and Viatris avoid an adverse merits ruling
Mylan Pharmaceuticals and Viatris exit the litigation without a finding of infringement or validity against them. The own-costs arrangement avoids fee-shifting. However, any settlement terms — such as a negotiated market entry date or licence conditions — will govern when and how Mylan’s ANDA product can reach market. The absence of a merits ruling means the patent’s validity was not tested publicly in this forum.
No infringement finding — terms privateSettlement dynamics consistent with a negotiated entry date
In Hatch-Waxman ANDA litigation, dismissal without prejudice combined with retained court jurisdiction strongly suggests a private settlement that includes a licensed market entry date or revenue-sharing arrangement. For the antipsychotic sector, this keeps the aripiprazole dosing method patent commercially viable. Competitors considering ANDA filings for similar aripiprazole formulations should treat US11400087B2 as an active enforcement risk pending any public licence disclosures.
Likely licensed entry — monitor disclosuresFull party and counsel information
| Role | Name | Type | Detail |
|---|---|---|---|
| Plaintiff | Otsuka Pharmaceutical Co., Ltd. | Company | Pharmaceutical innovator — holder of US11400087B2 covering aripiprazole CYP dosing methodsSearch in Eureka ↗ |
| Co-Plaintiff | H. Lundbeck, AS | Individual | Search in Eureka ↗ |
| Defendant | Mylan, NV | Company | Generic pharmaceutical group (Mylan NV, Mylan Pharmaceuticals, Viatris) seeking ANDA market entrySearch in Eureka ↗ |
| Co-Defendant | Mylan Pharmaceuticals, Inc. | Company | Search in Eureka ↗ |
| Co-Defendant | Viatris, Inc. | Company | Search in Eureka ↗ |
| Plaintiff counsel | Andrew Colin Mayo | Attorney | Counsel for Otsuka Pharmaceutical Co., Ltd.Search in Eureka ↗ |
| Plaintiff counsel | Steven J. Balick | Attorney | Counsel for Otsuka Pharmaceutical Co., Ltd.Search in Eureka ↗ |
| Plaintiff law firm | Ashby & Geddes PC | Law Firm | Representing Otsuka Pharmaceutical Co., Ltd.Search in Eureka ↗ |
| Defendant counsel | Andrew Mark Moshos | Attorney | Counsel for Mylan, NVSearch in Eureka ↗ |
| Defendant counsel | Bindu Ann George Palapura | Attorney | Counsel for Mylan, NVSearch in Eureka ↗ |
| Defendant counsel | Christine Dealy Haynes | Attorney | Counsel for Mylan, NVSearch in Eureka ↗ |
| Defendant counsel | David Ellis Moore | Attorney | Counsel for Mylan, NVSearch in Eureka ↗ |
| Defendant counsel | Frederick L. Cottrell , III | Attorney | Counsel for Mylan, NVSearch in Eureka ↗ |
| Defendant counsel | Jason James Rawnsley | Attorney | Counsel for Mylan, NVSearch in Eureka ↗ |
| Defendant law firm | Potter, Anderson & Corroon LLP | Law Firm | Representing Mylan, NVSearch in Eureka ↗ |
| Defendant law firm | Richards, Layton & Finger, PA | Law Firm | Representing Mylan, NVSearch in Eureka ↗ |
| Presiding judge | Judge Jennifer L. Hall | Judge | Delaware District CourtSearch in Eureka ↗ |
Official order — verbatim text
The stipulated dismissal language — ‘without prejudice’ with the court retaining jurisdiction — is significant beyond its procedural surface. It signals that the parties resolved underlying commercial terms privately, while preserving Otsuka and Lundbeck’s ability to re-litigate should those terms be breached. The own-costs provision is neutral and does not suggest either party conceded weakness. No merits determination was entered, meaning US11400087B2’s validity and scope were never adjudicated in this proceeding.
US11400087B2 — Aripiprazole dosing method for CYP-impaired patients
US11400087B2 (application no. US17/304606) protects a pharmacogenomics-based dosing method for aripiprazole — the active ingredient in antipsychotics such as Abilify. The patent specifically addresses patients whose CYP2D6 or CYP3A4 enzyme pathways are impaired, either genetically or through co-administration of inhibitors. Such patients metabolise aripiprazole differently, creating clinically meaningful dosing challenges. Method patents of this type are increasingly used to protect the commercial life of established compounds beyond formulation patents.
For the antipsychotic market, US11400087B2 represents a precision-medicine layer of protection that generic manufacturers must navigate carefully. ANDA applicants seeking to market aripiprazole must assess whether their labelling carves out or mirrors this dosing method. Because the patent survived this litigation without a validity ruling, it retains full presumptive validity. Competitors in the atypical antipsychotic space — particularly those filing paragraph IV certifications — should treat this patent as a live litigation risk when designing labelling strategy.
Should you run an FTO against US11400087B2?
Any pharmaceutical company with a pending or planned ANDA for aripiprazole — or a drug metabolised through CYP2D6 or CYP3A4 pathways — should assess exposure to US11400087B2. The patent’s method claims target dosing protocols, meaning even a product with a different formulation may be at risk if its proposed labelling includes guidance for CYP-impaired patients. This case demonstrates that Otsuka and Lundbeck are willing to litigate this asset aggressively in Delaware.
PatSnap Eureka’s FTO Search Agent can map the claim scope of US11400087B2 against your proposed labelling and product profile, identify relevant prior art that could support a challenge, and surface related patents in Otsuka’s and Lundbeck’s portfolios. R&D and regulatory teams planning CYP-sensitive dosing products should run a targeted clearance analysis before finalising any ANDA submission or NDA labelling that references CYP2D6 or CYP3A4 dosing adjustments.
Run a freedom-to-operate analysis on US11400087B2 to assess your product’s exposure
Run FTO in Eureka →Similar aripiprazole and CYP dosing method patent cases in Delaware
Explore related Hatch-Waxman infringement actions involving aripiprazole, CYP enzyme dosing methods, and antipsychotic ANDA disputes in the District of Delaware.
What this case signals for the antipsychotic patent IP landscape
This settlement-without-prejudice outcome reinforces the commercial durability of method patents in Hatch-Waxman litigation, particularly for pharmacogenomics-based dosing claims.
Method patents on dosing protocols remain potent enforcement tools
US11400087B2 survived 618 days of litigation without a validity challenge succeeding. Method patents covering CYP-sensitive dosing are harder to design around than formulation patents, since they attach to labelling rather than chemistry. Generic filers must treat such claims as live risks even for long-established active pharmaceutical ingredients like aripiprazole.
Retained jurisdiction signals a structured settlement — not a clean exit
When a Delaware court retains jurisdiction post-dismissal, it typically means the settlement includes ongoing obligations — most likely a negotiated generic entry date or revenue-sharing licence. ANDA watchers should monitor Mylan and Viatris aripiprazole product launches closely, as the launch timing will implicitly reveal the settlement’s commercial terms.
Otsuka v Mylan — key questions answered
US11400087B2 is a method patent held by Otsuka Pharmaceutical covering dosing protocols for aripiprazole in patients with impaired CYP2D6 or CYP3A4 enzyme function. It was asserted in a Hatch-Waxman infringement action against Mylan’s ANDA product, which would have referenced the same dosing methodology in its labelling. The case was filed in Delaware in September 2022.
A dismissal without prejudice means no merits ruling was entered and the patent’s validity or infringement was not adjudicated. Otsuka and Lundbeck retain the right to re-assert US11400087B2 against Mylan or Viatris in a future proceeding. The court retained jurisdiction over the parties, strongly suggesting a private settlement agreement underpins the dismissal.
Neither party won on the merits. The case was stipulated to dismissal without prejudice, meaning no finding of infringement or invalidity was entered. Both sides bear their own costs. The outcome is commercially neutral on its face, though a private settlement — potentially including a licensed entry date for Mylan’s aripiprazole generic — is strongly implied by the court’s retained jurisdiction clause.
CYP2D6 and CYP3A4 are liver enzymes responsible for metabolising aripiprazole. Patients with impaired function — whether genetic poor metabolisers or those taking CYP inhibitors — require adjusted dosing. Patent claims covering this dosing adjustment are pharmacogenomics method claims, which attach to labelling rather than molecular structure, making them difficult for generic manufacturers to design around without carving out the dosing guidance entirely.
Otsuka and Lundbeck were represented by Ashby & Geddes PC, with attorneys Andrew Colin Mayo and Steven J. Balick. Mylan and Viatris were represented by Potter Anderson & Corroon LLP and Richards, Layton & Finger PA, with a team including Frederick L. Cottrell III, David Ellis Moore, and Bindu Ann George Palapura, among others.
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