Bayer AG v. Lupin Limited: XARELTO 2.5 mg Patent Dispute Dismissed Without Prejudice
Bayer AG and Janssen Pharmaceuticals filed suit against Lupin Limited in the Delaware District Court, asserting US10828310B2 against Lupin’s generic version of XARELTO 2.5 mg (rivaroxaban). After 264 days of litigation, plaintiffs voluntarily dismissed all claims without prejudice under Rule 41(a)(1)(A)(i), preserving the right to refile.
XARELTO 2.5 mg: Bayer’s Pre-Trial Voluntary Exit in Delaware ANDA Battle
On 20 March 2025, Bayer AG and Janssen Pharmaceuticals, Inc. filed a patent infringement action in the Delaware District Court (Case No. 1:25-cv-00349) against Lupin Limited. The suit asserted US10828310B2 — a patent covering the rivaroxaban 2.5 mg formulation marketed as XARELTO — against Lupin’s abbreviated new drug application (ANDA) for a generic equivalent. The case was assigned to Judge Richard G. Andrews, a judge with extensive experience in pharmaceutical patent matters in Delaware.
On 9 December 2025, after 264 days of litigation, the plaintiffs filed a notice of voluntary dismissal under Federal Rule of Civil Procedure 41(a)(1)(A)(i), terminating all claims without prejudice. A dismissal without prejudice means that no judgment was entered on the merits and the plaintiffs are legally entitled to refile the same claims in the future, subject to applicable statutes of limitations and any strategic considerations.
The relatively compressed 264-day timeline — well before any anticipated trial date in a typical ANDA case — suggests the parties may have reached a commercial resolution, licensing arrangement, or that plaintiffs identified a tactical reason to reset the litigation posture. The public record does not disclose settlement terms or the specific catalyst for the dismissal, leaving the underlying commercial dynamics opaque. Lupin’s ANDA status and any 30-month stay implications remain subject to separate FDA regulatory proceedings.
Filing to Voluntary dismissal in 264 days
264 days — shorter than the median ANDA patent litigation in Delaware, which typically runs 2–4 years to trial
Voluntarily dismissed without prejudice: what this means for both parties
Rule 41(a)(1)(A)(i): Plaintiff’s unilateral exit before answer or summary judgment
Under Fed. R. Civ. P. 41(a)(1)(A)(i), a plaintiff may dismiss an action without a court order by filing a notice before the opposing party serves an answer or a motion for summary judgment. This mechanism is entirely within the plaintiff’s control and carries no merits adjudication. The case is terminated as if it never proceeded to judgment, and no preclusive effect attaches to the dismissal itself.
No merits rulingWithout prejudice: Bayer preserves the right to refile
A dismissal ‘without prejudice’ means the plaintiffs are not barred from asserting the same patent claims against Lupin’s ANDA product again in future proceedings. This is a critical commercial distinction: Bayer and Janssen retain full enforcement rights under US10828310B2. The public record does not disclose whether a settlement was reached or whether the parties entered a separate commercial agreement that prompted the dismissal.
Refiling rights preservedLupin faces no injunction but gains no cleared path
The dismissal without prejudice does not constitute a patent invalidity finding or a non-infringement ruling in Lupin’s favour. Lupin’s generic rivaroxaban 2.5 mg product is not judicially cleared for launch. The 30-month stay triggered by the original Hatch-Waxman certification may have independent regulatory implications that are unaffected by this civil dismissal. Lupin remains exposed to a refiled suit if it proceeds toward commercial launch.
No freedom-to-operate grantedEarly exit suggests possible settlement or strategic reset for XARELTO IP defence
Voluntary pre-trial dismissals in ANDA litigation at this stage typically signal either a negotiated settlement (often involving a licensed entry date), a strategic litigation reset, or a change in patent or product landscape. For the broader rivaroxaban generic sector, this outcome leaves US10828310B2 intact and enforceable. Other ANDA filers targeting the 2.5 mg dosage should treat this patent as a live enforcement risk until further public disclosures clarify terms.
Patent remains enforceableFull party and counsel information
| Role | Name | Type | Detail |
|---|---|---|---|
| Plaintiff | Bayer AG | Company | Global pharmaceutical company — holder of US10828310B2 covering XARELTO 2.5 mg rivaroxabanSearch in Eureka ↗ |
| Defendant | Lupin Limited | Individual | Lupin Limited — Indian generic pharmaceutical manufacturer pursuing US ANDA approval for rivaroxaban 2.5 mgSearch in Eureka ↗ |
| Plaintiff counsel | Derek James Fahnestock | Attorney | Counsel for Bayer AGSearch in Eureka ↗ |
| Plaintiff counsel | Rodger Dallery Smith , II | Attorney | Counsel for Bayer AGSearch in Eureka ↗ |
| Plaintiff law firm | Morris, Nichols, Arsht & Tunnell LLP | Law Firm | Representing Bayer AGSearch in Eureka ↗ |
| Defendant counsel | John C. Phillips , Jr. | Attorney | Counsel for Lupin LimitedSearch in Eureka ↗ |
| Defendant counsel | Megan C. Haney | Attorney | Counsel for Lupin LimitedSearch in Eureka ↗ |
| Defendant law firm | Phillips, McLaughlin & Hall PA | Law Firm | Representing Lupin LimitedSearch in Eureka ↗ |
| Presiding judge | Judge Richard G. Andrews | Judge | Delaware District CourtSearch in Eureka ↗ |
Official order — verbatim text
The voluntary dismissal notice invokes Rule 41(a)(1)(A)(i) explicitly, confirming that no answer or summary judgment motion had been served by Lupin before the filing. The ‘without prejudice’ designation is the operative legal term: it means no judgment on the merits exists, no estoppel attaches to Bayer or Janssen, and US10828310B2 remains fully enforceable. The phrasing is consistent with a unilateral plaintiff decision — there is no indication from the notice text of a consent order or mutual agreement, though a separate undisclosed commercial arrangement cannot be excluded from the public record.
US10828310B2 — Rivaroxaban 2.5 mg XARELTO Formulation Patent
US10828310B2 (application number US16/264032) covers the pharmaceutical formulation of rivaroxaban at the 2.5 mg dosage — the lower-strength version of XARELTO used primarily for reducing cardiovascular risk in patients with chronic coronary artery disease or peripheral arterial disease, often in combination with aspirin. The application entered prosecution under Bayer’s pharmaceutical patent estate and issued as a granted US patent. The ‘B2’ designation indicates the patent was published with amended claims following examination, suggesting the claim scope was refined during prosecution.
For the rivaroxaban market, the 2.5 mg dosage occupies a distinct clinical segment from the higher-strength anticoagulation indications, and Bayer’s ability to assert formulation patents at this dosage creates a separate layer of IP protection beyond the compound patent. US10828310B2 represents a formulation-level barrier for generic entrants — exactly the type of secondary patent that ANDA filers must address via Paragraph IV certifications. With the original litigation now dismissed without prejudice, the enforceability of this patent against Lupin and any other ANDA filer for rivaroxaban 2.5 mg remains intact and commercially significant.
Should your team run an FTO against US10828310B2?
Any pharmaceutical developer, generic manufacturer, or contract development organisation working on rivaroxaban 2.5 mg oral solid dosage forms should treat US10828310B2 as a live enforcement risk. The voluntary dismissal in this case does not represent a judicial invalidity finding or a non-infringement determination. If your ANDA or 505(b)(2) application targets this dosage strength, a current FTO analysis of US10828310B2 — including its prosecution history and claim construction — is essential before filing a Paragraph IV certification or advancing toward commercial manufacture.
PatSnap Eureka’s FTO Search Agent can map the full claim landscape of US10828310B2 against your formulation parameters, flag related Bayer and Janssen patents in the rivaroxaban estate, and surface prior art that may support a design-around or invalidity argument. The tool also tracks litigation history across the ANDA docket, so your IP team can benchmark risk against what other generic filers have faced on this molecule. Run a targeted FTO before your next regulatory filing milestone.
Run a freedom-to-operate analysis on US10828310B2 to assess your product’s exposure
Run FTO in Eureka →Similar ANDA Rivaroxaban Patent Cases in Delaware District Court
Cases involving rivaroxaban XARELTO formulation patents litigated in the Delaware District Court under the Hatch-Waxman ANDA framework.
What this case signals for the rivaroxaban generic IP landscape
Bayer’s early voluntary exit in Delaware raises questions about XARELTO’s 2.5 mg patent defence posture that generic filers cannot afford to ignore.
US10828310B2 remains live: do not treat dismissal as patent clearance
A Rule 41 voluntary dismissal without prejudice carries zero preclusive effect on the asserted patent. US10828310B2 is fully enforceable. Generic manufacturers targeting rivaroxaban 2.5 mg should conduct a current FTO analysis — this dismissal changes nothing about the patent’s legal status or Bayer’s ability to refile.
Timing suggests commercial resolution — watch for SEC or FDA disclosures
The 264-day timeline is atypically short for an ANDA case going to trial. The pattern is consistent with a negotiated settlement or authorised generic agreement. Neither party has publicly disclosed terms. Monitoring Lupin’s FDA ANDA filings and Bayer’s earnings disclosures may surface relevant information about any licensed entry date for the generic.
Bayer v Lupin — key questions answered
The dismissal without prejudice means no judgment was entered on the merits of the patent infringement claims. Bayer AG and Janssen Pharmaceuticals retain full rights to refile the same claims asserting US10828310B2 against Lupin’s generic rivaroxaban 2.5 mg product. The patent itself remains valid and enforceable; Lupin received no judicial clearance to launch its generic.
Bayer asserted US10828310B2 (application number US16/264032), a patent covering the rivaroxaban 2.5 mg pharmaceutical formulation marketed as XARELTO. The suit targeted Lupin’s ANDA seeking approval for a generic version of the 2.5 mg XARELTO product.
The public record does not disclose the specific reason for the early voluntary dismissal. The 264-day duration — well before a typical ANDA trial schedule — is consistent with a negotiated settlement, a licensed entry date agreement, or a strategic litigation reset. No terms have been publicly disclosed by either party.
The civil dismissal under Rule 41(a)(1)(A)(i) does not automatically dissolve a 30-month stay that may have been triggered by Lupin’s Paragraph IV certification. The stay’s regulatory status is governed separately by the Hatch-Waxman Act and FDA’s Orange Book procedures, independent of the litigation outcome. Parties should monitor FDA docket entries for Lupin’s ANDA to assess the current stay status.
No. A voluntary dismissal without prejudice has no preclusive or estoppel effect on third parties. Other ANDA filers targeting rivaroxaban 2.5 mg cannot cite this outcome as patent clearance. US10828310B2 remains fully enforceable against any party who has not obtained a separate non-infringement ruling or licence, and each filer must independently address the patent in their Paragraph IV certification.
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