Bayer AG v. Dr. Reddy’s Laboratories: XARELTO® Rivaroxaban Patent Action Dismissed
Bayer AG and Janssen Pharmaceuticals brought an infringement action against Dr. Reddy’s Laboratories in Delaware over US10828310B2, a patent covering 2.5 mg rivaroxaban (XARELTO®) tablets. The case was voluntarily dismissed without prejudice after just 113 days, leaving the door open for future proceedings.
Early exit in Delaware XARELTO® ANDA case — but without prejudice
On August 19, 2025, Bayer AG and Janssen Pharmaceuticals, Inc. filed suit against Dr. Reddy’s Laboratories, Ltd. in the District of Delaware before Judge Richard G. Andrews. The complaint asserted infringement of US10828310B2, a patent directed to 2.5 mg rivaroxaban formulations sold under the XARELTO® brand — a Factor Xa inhibitor widely prescribed for thromboembolism prevention. The action was consistent with standard Hatch-Waxman ANDA litigation, triggered by Dr. Reddy’s paragraph IV certification challenging the patent.
The case closed on December 10, 2025, just 113 days after filing. Pursuant to Fed. R. Civ. P. 41(a)(1)(A)(i), plaintiffs filed a unilateral notice of voluntary dismissal — the earliest and most procedurally straightforward mechanism available, requiring no court order and filed before any answer or motion for summary judgment. Critically, the dismissal was entered without prejudice, meaning Bayer and Janssen retain the right to refile claims against Dr. Reddy’s on the same patent.
The speed of resolution — roughly four months from filing to dismissal — is notable and suggests the parties may have reached a confidential settlement, licensing arrangement, or consent agreement governing Dr. Reddy’s market entry, though the public record is silent on terms. Alternatively, the dismissal could reflect a strategic recalibration of the patent enforcement portfolio. The without-prejudice designation preserves optionality but also means the underlying patent’s enforceability against Dr. Reddy’s product remains formally unresolved.
Filing to Voluntary dismissal in 113 days
113 days — resolved well before the typical Delaware ANDA trial schedule of 2–3 years
Voluntarily dismissed: what the Rule 41 notice means for both parties
Rule 41(a)(1)(A)(i): no court order, plaintiff’s unilateral right
Under Fed. R. Civ. P. 41(a)(1)(A)(i), a plaintiff may dismiss without a court order by filing a notice before the defendant serves an answer or a motion for summary judgment. This is the most permissive dismissal route available — it requires no judicial approval and takes effect immediately upon filing. Its use here suggests the case was terminated very early in the litigation lifecycle, before substantive defensive pleadings were exchanged.
Procedural dismissal — no merits rulingClaims survive: Bayer retains the right to refile
A without-prejudice dismissal does not extinguish the underlying claims. Bayer AG and Janssen may refile the same infringement action against Dr. Reddy’s based on US10828310B2 at a future date, subject to any applicable statute of limitations. This is legally distinct from a with-prejudice dismissal, which would bar refiling. The public record does not disclose whether any settlement agreement, consent judgment, or license governs the parties’ ongoing relationship — that information, if it exists, is private.
Claims preserved — refiling possibleDr. Reddy’s faces no injunction — but patent cloud remains
The dismissal without prejudice provides Dr. Reddy’s with immediate litigation relief but not long-term certainty. No court has ruled on the validity or enforceability of US10828310B2, meaning Dr. Reddy’s cannot rely on this proceeding as precedent. If a confidential agreement governs market entry timing, the dismissal would be consistent with a negotiated launch date. Absent such an agreement, the patent cloud over Dr. Reddy’s 2.5 mg rivaroxaban ANDA product persists.
No merits determination — uncertainty remainsXARELTO® generic entry timeline remains commercially sensitive
XARELTO® (rivaroxaban) is a high-revenue anticoagulant. The 2.5 mg dose — used for cardiovascular risk reduction — carries distinct commercial significance from higher-dose formulations. The swift dismissal, without any public licensing terms, makes it difficult for competitors and market watchers to model generic entry timing. Other ANDA filers watching Dr. Reddy’s proceedings should note that without-prejudice dismissals in Hatch-Waxman cases frequently accompany confidential consent agreements.
Generic entry timing uncertainFull party and counsel information
| Role | Name | Type | Detail |
|---|---|---|---|
| Plaintiff | Bayer AG | Company | Pharmaceutical innovator — holder of US10828310B2 covering 2.5 mg rivaroxaban (XARELTO®)Search in Eureka ↗ |
| Defendant | Dr. Reddy’s Laboratories, Ltd. | Company | Generic pharmaceutical manufacturer seeking ANDA approval for 2.5 mg rivaroxaban tabletsSearch 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 | Daniel Taylor | Attorney | Counsel for Dr. Reddy’s Laboratories, Ltd.Search in Eureka ↗ |
| Defendant counsel | Neal C. Belgam | Attorney | Counsel for Dr. Reddy’s Laboratories, Ltd.Search in Eureka ↗ |
| Defendant law firm | Smith, Katzenstein & Jenkins LLP | Law Firm | Representing Dr. Reddy’s Laboratories, Ltd.Search in Eureka ↗ |
| Presiding judge | Judge Richard G. Andrews | Judge | Delaware District CourtSearch in Eureka ↗ |
Official order — verbatim text
The dismissal notice invokes Rule 41(a)(1)(A)(i) with explicit without-prejudice language, which carries precise legal consequences: no adjudication on the merits, no preclusive effect, and Bayer’s claims remain live. The filing of a unilateral notice — rather than a stipulated dismissal under Rule 41(a)(1)(A)(ii) — suggests Dr. Reddy’s had not yet answered, consistent with the case’s early closure. The without-prejudice designation is legally significant because it preserves Bayer’s enforcement rights against Dr. Reddy’s on US10828310B2 in any future proceeding.
US10828310B2 — 2.5 mg rivaroxaban (XARELTO®) oral anticoagulant formulation
US10828310B2, filed under application number US16/264032, protects formulations of rivaroxaban at the 2.5 mg dosage — the specific dose approved for reducing cardiovascular risk in patients with coronary artery disease or peripheral arterial disease in combination with aspirin. Rivaroxaban is a direct Factor Xa inhibitor, and the 2.5 mg dose represents a distinct clinical and formulation target from the higher doses used for anticoagulation. The patent’s coverage of this specific dose and formulation makes it a critical barrier to ANDA-based generic entry at this dose level.
From a strategic standpoint, the 2.5 mg XARELTO® dosage occupies a high-value segment of the rivaroxaban franchise. A patent covering this formulation can operate as a significant lifecycle extension asset, potentially delaying generic competition beyond expiry of earlier compound patents. For generic manufacturers — including Dr. Reddy’s and others with pending ANDAs — US10828310B2 represents a primary enforcement target. Competitors should assess whether their proposed formulations and manufacturing processes fall within the patent’s claims before advancing regulatory filings.
Should your team run an FTO analysis against US10828310B2?
Any pharmaceutical company developing, formulating, or seeking ANDA approval for 2.5 mg rivaroxaban tablets should treat US10828310B2 as a priority FTO target. The patent remains in force, has not been invalidated in any proceeding, and Bayer has demonstrated willingness to enforce it through litigation. The without-prejudice dismissal in this case does not reduce the patent’s legal reach — it leaves the claim scope fully intact against the market.
PatSnap Eureka’s FTO Search Agent allows R&D and regulatory teams to map US10828310B2’s claim landscape against proposed rivaroxaban formulation specifications, identify related continuation or divisional filings in Bayer’s portfolio, and surface any inter partes review petitions or reexamination proceedings. Running a structured FTO analysis before ANDA submission significantly reduces downstream litigation exposure in this competitive Hatch-Waxman environment.
Run a freedom-to-operate analysis on US10828310B2 to assess your product’s exposure
Run FTO in Eureka →Similar rivaroxaban and oral anticoagulant ANDA patent cases in Delaware
Related Hatch-Waxman infringement cases asserting XARELTO® and rivaroxaban formulation patents in Delaware District Court, including comparable Rule 41 dismissals.
What this case signals for the rivaroxaban and oral anticoagulant IP landscape
A 113-day without-prejudice dismissal in a Delaware ANDA case rarely means the dispute is truly over — it typically signals a negotiated resolution.
Without-prejudice ANDA dismissals frequently mask confidential consent agreements
In Hatch-Waxman litigation, voluntary dismissals — especially at this early stage — are strongly associated with private settlement or consent agreements governing generic launch dates. Patent practitioners monitoring the XARELTO® competitive landscape should treat this dismissal as a signal of a negotiated outcome rather than a litigation failure, even though no terms are publicly available.
US10828310B2 remains unchallenged on the merits — enforceability intact
Because the case was dismissed before any substantive proceedings, US10828310B2 has not been subjected to judicial scrutiny of validity or infringement. The patent retains full presumptive validity. Other generic filers or competitors considering rivaroxaban formulations should treat this patent as an active enforcement risk and conduct FTO analysis before advancing ANDA filings.
Bayer v Dr. — key questions answered
The voluntary dismissal without prejudice means Bayer AG and Janssen Pharmaceuticals ended the lawsuit without any court ruling on the merits of the patent infringement claims. Under Rule 41(a)(1)(A)(i), this dismissal required no court order and took effect immediately. Critically, it preserves Bayer’s right to refile infringement claims based on US10828310B2 against Dr. Reddy’s in the future — the patent’s enforceability was not adjudicated.
US10828310B2 (application US16/264032) is a Bayer patent covering formulations of rivaroxaban at the 2.5 mg dose. This specific dose of XARELTO® is approved for reducing cardiovascular risk in patients with stable coronary artery or peripheral arterial disease. The patent’s coverage of this dosage form makes it a key Hatch-Waxman litigation asset, potentially extending exclusivity beyond earlier rivaroxaban compound patents.
The 113-day duration is consistent with a negotiated resolution in Hatch-Waxman ANDA litigation, though the public record does not confirm any settlement terms. In such cases, early dismissals frequently accompany confidential consent agreements establishing agreed launch dates or licensing arrangements. The use of a unilateral Rule 41(a)(1)(A)(i) notice — rather than a stipulated dismissal — suggests Dr. Reddy’s had not yet filed an answer, indicating resolution occurred very early in the litigation timeline.
The dismissal without prejudice does not constitute judicial clearance for Dr. Reddy’s to launch. No court ruled on the validity or non-infringement of US10828310B2. If no confidential agreement governs launch timing, the patent remains a potential enforcement barrier. The 30-month stay triggered by Bayer’s timely ANDA suit may or may not have expired depending on timing; Dr. Reddy’s would need FDA approval and patent clearance before commercial launch.
Bayer AG and Janssen Pharmaceuticals were represented by Morris, Nichols, Arsht & Tunnell LLP, with attorneys Derek James Fahnestock and Rodger Dallery Smith II on record. Dr. Reddy’s Laboratories was represented by Smith, Katzenstein & Jenkins LLP, with attorneys Daniel Taylor and Neal C. Belgam listed as counsel. Both firms are established Delaware litigation practices frequently engaged in Hatch-Waxman proceedings.
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