Bayer & Janssen v. Taro Pharmaceutical: XARELTO® Rivaroxaban Patent Dismissed With Prejudice
Bayer AG and Janssen Pharmaceuticals filed suit against Taro Pharmaceutical in the Delaware District Court over US10828310B2, covering 2.5 mg XARELTO® rivaroxaban tablets. After 1,619 days of litigation, all claims and counterclaims were dismissed with prejudice by mutual stipulation, with each party bearing its own costs.
A four-year ANDA patent battle ends by mutual consent — with finality
On 7 July 2021, Bayer AG and Janssen Pharmaceuticals, Inc. filed suit against Taro Pharmaceutical Industries, Ltd. and Taro Pharmaceuticals U.S.A., Inc. in the District of Delaware, asserting infringement of US10828310B2. The patent at issue covers formulations of rivaroxaban at the 2.5 mg dosage strength, marketed under the brand name XARELTO® — one of the world’s best-selling anticoagulants. The action was brought under the Hatch-Waxman framework, typically triggered by Taro’s ANDA filing seeking FDA approval to market a generic version of the 2.5 mg tablet.
The case was resolved on 12 December 2025 when all parties executed a stipulated dismissal under Federal Rules of Civil Procedure 41(a)(1) and 41(c), dismissing every claim and counterclaim with prejudice. The with-prejudice designation is legally significant: neither Bayer, Janssen, nor Taro may relitigate the same claims arising from this patent and product pairing. Each party agreed to bear its own costs, disbursements, and attorneys’ fees, signalling a negotiated resolution rather than a court-ordered outcome.
The 1,619-day duration — nearly four and a half years — is notable for an ANDA case that ultimately settled without a merits ruling. Cases of this length in Delaware often involve substantive claim construction briefing, expert discovery, and sometimes trial preparation before resolution. The absence of any publicly disclosed settlement terms or licence agreement leaves open the question of whether Taro secured market access rights, delayed entry, or simply agreed to withdraw its ANDA challenge. The public record is silent on the commercial terms driving the stipulation.
Filing to Dismissed with Prejudice in 1619 days
1,619 days — over four years, well above the median ANDA pharma case in Delaware
Dismissed with prejudice: what the stipulation means for both parties
Rule 41 with-prejudice dismissal closes all doors permanently
A dismissal with prejudice under Rule 41(a)(1) and 41(c) operates as a final adjudication on the merits. Neither side may bring the same claims before any court again. Unlike a dismissal without prejudice — which preserves the right to refile — this stipulation permanently extinguishes all patent infringement claims and invalidity counterclaims asserted in this action. The court retains no further jurisdiction over the substance of this dispute.
Permanent bar on re-litigationBayer and Janssen avoid an adverse validity ruling
A with-prejudice dismissal before any merits decision means US10828310B2 was never adjudicated invalid or unenforceable in this action. The patent remains in force against third parties. Bayer and Janssen preserve the patent’s enforceability while avoiding the litigation risk of an adverse finding. Any undisclosed licence or consent agreement with Taro would add a further layer of commercial protection without creating public precedent.
Patent validity preservedTaro’s invalidity counterclaims are extinguished with prejudice
Taro’s defensive counterclaims — which in ANDA litigation typically include patent invalidity and non-infringement arguments — are dismissed with prejudice alongside the plaintiffs’ claims. This bars Taro from relitigating those specific invalidity arguments against US10828310B2. Whether Taro secured any commercial benefit (e.g. an authorised generic agreement or a launch date) is not disclosed in the public record. Absent such terms, Taro’s path to the 2.5 mg rivaroxaban market via this ANDA is substantially constrained.
Counterclaims permanently closedXARELTO® 2.5 mg exclusivity landscape remains opaque post-settlement
The resolution without a public merits ruling leaves the anticoagulant generic market in an uncertain position. Other ANDA filers targeting the 2.5 mg rivaroxaban dosage cannot rely on this case to establish invalidity precedent. The 30-month stay typical in Hatch-Waxman actions would have long expired by the December 2025 closure, suggesting FDA timing and any agreed exclusivity period are the operative commercial variables. Competitors and investors should monitor Taro’s FDA approval status and any authorised generic disclosures.
No invalidity precedent createdFull party and counsel information
| Role | Name | Type | Detail |
|---|---|---|---|
| Plaintiff | Bayer AG | Company | Pharmaceutical patent holders — global developers and licensors of XARELTO® (rivaroxaban), holder of US10828310B2Search in Eureka ↗ |
| Co-Plaintiff | Janssen Pharmaceuticals, Inc. | Company | Search in Eureka ↗ |
| Co-Plaintiff | Bayer AG | Company | Search in Eureka ↗ |
| Defendant | Taro Pharmaceutical Industries, Ltd. | Company | Generic pharmaceutical manufacturer seeking ANDA approval for 2.5 mg rivaroxaban tabletsSearch in Eureka ↗ |
| Co-Defendant | Taro Pharmaceuticals U.S.A., Inc. | Company | Search in Eureka ↗ |
| Plaintiff counsel | Derek James Fahnestock | Attorney | Counsel for Bayer AGSearch in Eureka ↗ |
| Plaintiff counsel | Jack B. Blumenfeld | 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 | Anne Shea Gaza | Attorney | Counsel for Taro Pharmaceutical Industries, Ltd.Search in Eureka ↗ |
| Defendant counsel | Kimberly A. Beis | Attorney | Counsel for Taro Pharmaceutical Industries, Ltd.Search in Eureka ↗ |
| Defendant counsel | Stephen P. Benson | Attorney | Counsel for Taro Pharmaceutical Industries, Ltd.Search in Eureka ↗ |
| Defendant law firm | Young Conaway Stargatt & Taylor, LLP | Law Firm | Representing Taro Pharmaceutical Industries, Ltd.Search in Eureka ↗ |
| Presiding judge | Judge Richard G. Andrews | Judge | Delaware District CourtSearch in Eureka ↗ |
Official order — verbatim text
The stipulation invokes both Rule 41(a)(1) — governing voluntary dismissal of plaintiffs’ claims — and Rule 41(c), which extends those dismissal mechanics to counterclaims asserted by defendants. The explicit with-prejudice designation means the dismissal carries the force of a final judgment on the merits, foreclosing any future litigation on the same claims between these parties. The mutual cost-bearing clause — each side absorbing its own fees — is a standard feature of negotiated ANDA resolutions and neither confirms nor denies the existence of a parallel commercial agreement between Bayer, Janssen, and Taro governing rivaroxaban market access.
US10828310B2 — 2.5 mg Rivaroxaban (XARELTO®) Tablet Formulation
US10828310B2 (application number US16/264032) covers formulations of rivaroxaban at the 2.5 mg dosage strength, the lowest commercially approved dose of the Factor Xa inhibitor marketed as XARELTO®. This dosage is specifically approved for reducing cardiovascular risk in patients with coronary or peripheral artery disease, a distinct and high-value indication separate from the higher-dose atrial fibrillation and VTE treatment uses. The application’s filing history and prosecution reflect Bayer’s strategy of protecting dosage-specific formulation innovations as a secondary IP layer over the core rivaroxaban compound.
For generic pharmaceutical companies, US10828310B2 represents a key blocking patent for the 2.5 mg rivaroxaban ANDA pathway. The cardiovascular risk reduction indication carries a substantial patient population, making the 2.5 mg tablet a commercially attractive generic target. Bayer and Janssen’s willingness to litigate for over four years — and then resolve without a public merits ruling — underscores the patent’s strategic value within the XARELTO® orange book listing estate. Competitors pursuing this space must evaluate both this patent and co-listed formulation and method-of-use patents before finalising their ANDA strategy.
Should your product team run an FTO against US10828310B2?
Any pharmaceutical company developing, formulating, or seeking ANDA approval for a 2.5 mg rivaroxaban tablet — or a structurally similar Factor Xa inhibitor composition — should treat US10828310B2 as a mandatory FTO checkpoint. The patent has never been invalidated. Its claims survived four years of adversarial ANDA litigation without judicial narrowing. R&D teams exploring solid oral dosage formulations in the anticoagulant category should assess claim scope before committing to process development or regulatory filing.
PatSnap Eureka’s FTO Search Agent enables IP and R&D teams to map claim coverage against US10828310B2 and the broader XARELTO® orange book patent family in a single workflow. The agent surfaces relevant prior art, identifies claim dependencies, and flags related Bayer and Janssen continuation applications that may extend protection beyond US10828310B2’s expiry. This is particularly critical given that the dismissal in Case No. 1:21-cv-01000 creates no invalidity precedent that a future challenger could rely upon.
Run a freedom-to-operate analysis on US10828310B2 to assess your product’s exposure
Run FTO in Eureka →Similar Hatch-Waxman ANDA cases involving oral anticoagulant formulation patents
Cases involving ANDA patent disputes over oral anticoagulant and Factor Xa inhibitor formulations in Delaware District Court, resolved by stipulated dismissal or bench trial.
What this case signals for the XARELTO® and oral anticoagulant IP landscape
A four-year Hatch-Waxman battle ending in a with-prejudice stipulation carries specific strategic signals for generic entry, patent enforcement, and portfolio management.
With-prejudice dismissals in ANDA cases rarely reflect litigation weakness alone
When both sides agree to extinguish all claims with prejudice after years of litigation, it consistently suggests a negotiated commercial resolution — often a licence, authorised generic arrangement, or agreed entry date. IP teams should treat this dismissal as a signal to monitor Taro’s ANDA approval status and any subsequent market entry announcements for 2.5 mg rivaroxaban.
US10828310B2 has never been invalidated — it remains a live enforcement risk
Because no court has ruled on validity or infringement, US10828310B2 retains full presumptive validity. Any company developing or marketing a 2.5 mg rivaroxaban formulation — or a closely related anticoagulant composition — should conduct a freedom-to-operate analysis against this patent before advancing to commercialisation. The patent’s enforceability against non-Taro parties is entirely undiminished.
Bayer v Taro — key questions answered
The case was dismissed with prejudice by stipulation of all parties on 12 December 2025, after 1,619 days of litigation. All claims by Bayer and Janssen against Taro, and all counterclaims by Taro against Bayer and Janssen, were permanently extinguished. Each party bore its own costs and attorneys’ fees.
The patent asserted was US10828310B2 (application number US16/264032), covering formulations of rivaroxaban at the 2.5 mg dosage strength — the XARELTO® tablet indicated for cardiovascular risk reduction in patients with coronary or peripheral artery disease.
A with-prejudice dismissal means the court never ruled on patent validity or infringement, so US10828310B2 retains its full presumptive validity. The dismissal creates no invalidity precedent that other ANDA filers can use. Bayer and Janssen remain free to assert the patent against any third party that files an ANDA for 2.5 mg rivaroxaban without authorisation.
The 1,619-day duration is consistent with ANDA cases in Delaware involving complex pharmaceutical formulation patents where parties engage in full fact and expert discovery, claim construction proceedings, and sometimes summary judgment motions before resolving commercially. The public record does not disclose specific procedural milestones, but the duration suggests substantive litigation activity prior to the stipulated resolution.
Plaintiffs were Bayer AG, Bayer Pharma AG, and Janssen Pharmaceuticals, Inc., represented by Morris, Nichols, Arsht & Tunnell LLP (attorneys Jack B. Blumenfeld, Derek James Fahnestock, and Rodger Dallery Smith II). Defendants were Taro Pharmaceutical Industries, Ltd. and Taro Pharmaceuticals U.S.A., Inc., represented by Young Conaway Stargatt & Taylor, LLP (attorneys Anne Shea Gaza, Kimberly A. Beis, and Stephen P. Benson). The case was presided over by Judge Richard G. Andrews.
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