Azurity Pharmaceuticals v. Aurobindo Pharma: Vancomycin Oral Liquid Patent Dispute Dismissed
Azurity Pharmaceuticals asserted seven patents covering vancomycin oral liquid formulations against Aurobindo’s ANDA filing in the District of New Jersey. After 503 days of litigation, the parties stipulated to dismiss all claims and counterclaims without prejudice — and notably agreed to extinguish the 30-month FDA approval stay protecting Aurobindo’s ANDA.
Hatch-Waxman ANDA battle over vancomycin liquid ends in stipulated dismissal
Azurity Pharmaceuticals, Inc. filed suit on 21 December 2023 in the U.S. District Court for the District of New Jersey against Aurobindo Pharma Ltd. and its U.S. subsidiary, Aurobindo Pharma USA, Inc. The action was triggered by Aurobindo’s ANDA No. 218130 seeking FDA approval for a generic vancomycin oral liquid product. Azurity asserted seven U.S. patents — US11638692B2, US10959947B2, US10959949B2, US10493028B2, US10959946B2, US10959948B2, and US10688046B2 — each directed to compositions and methods relating to vancomycin oral liquid formulations.
The case closed on 7 May 2025 via a joint stipulation filed pursuant to Rule 41(a)(2) of the Federal Rules of Civil Procedure. The parties agreed to dismiss all claims and counterclaims without prejudice, meaning neither side obtained a merits ruling on patent validity or infringement. A significant commercial term embedded in the stipulation is the express extinguishment of the 30-month FDA approval stay that had been triggered under 21 U.S.C. § 355(j)(5)(B)(iii), effectively clearing the regulatory path for Aurobindo’s ANDA to advance — subject to FDA review.
The 503-day duration suggests meaningful litigation activity before the parties reached resolution, though the public record does not disclose whether settlement discussions, licensing negotiations, or a commercial agreement drove the outcome. The without-prejudice dismissal leaves open the theoretical possibility of re-filing, but the extinguishment of the 30-month stay is a concrete, irrevocable concession by Azurity that likely signals a broader commercial understanding. What drove that concession remains unknown from the public docket.
Filing to Dismissed without Prejudice in 503 days
503 days — typical ANDA Hatch-Waxman cases often resolve within 12–30 months
Dismissed without prejudice: what the stipulated exit means for both parties
Rule 41(a)(2) stipulated dismissal without prejudice
A Rule 41(a)(2) dismissal by stipulation requires court approval and dissolves the action without a merits ruling. ‘Without prejudice’ means Azurity retains the theoretical right to re-file on the same patents against Aurobindo, though strategic and commercial realities — particularly the agreed extinguishment of the 30-month stay — typically make re-litigation unlikely without new triggering events.
No merits ruling issuedAzurity surrenders the FDA stay but preserves its patent portfolio
By agreeing to extinguish the 30-month stay on Aurobindo’s ANDA No. 218130, Azurity gave up its primary Hatch-Waxman regulatory shield. The without-prejudice dismissal nominally preserves future enforcement rights across all seven patents, but Azurity’s willingness to release the stay suggests it secured offsetting value — likely in the form of a licensing or supply arrangement not reflected in the public record.
Stay extinguished; patents intactAurobindo’s ANDA path cleared — FDA approval stay removed
The extinguishment of the 30-month stay is the most commercially significant outcome for Aurobindo. With the regulatory hold lifted, FDA approval of ANDA No. 218130 can proceed on its normal review timeline. Aurobindo obtained this result without a court ruling on the merits of the seven asserted patents — a favourable procedural outcome that avoids the risk of an adverse validity or infringement finding.
ANDA regulatory path clearedSeven patents survive unchallenged — a complex IP landscape for vancomycin liquid
No patent was found invalid or non-infringed, leaving Azurity’s seven-patent portfolio over vancomycin oral liquid formulations judicially untested. Other generic filers targeting this product category face an unresolved IP landscape. The without-prejudice dismissal means prior art arguments and claim construction positions developed in this litigation were never adjudicated — and could resurface in future ANDA challenges from other filers.
Portfolio unchallenged by courtFull party and counsel information
| Role | Name | Type | Detail |
|---|---|---|---|
| Plaintiff | Azurity Pharmaceuticals, Inc. | Company | Specialty pharmaceutical company — holder of US11638692B2 and 6 related vancomycin oral liquid patentsSearch in Eureka ↗ |
| Defendant | Aurobindo Pharma, Ltd. | Company | Generic pharmaceutical manufacturer (India-based, with U.S. subsidiary) seeking ANDA approval for vancomycin oral liquidSearch in Eureka ↗ |
| Co-Defendant | Aurobindo Pharma USA, Inc. | Company | Search in Eureka ↗ |
| Plaintiff counsel | Arnold B. Calmann | Attorney | Counsel for Azurity Pharmaceuticals, Inc.Search in Eureka ↗ |
| Plaintiff counsel | Katherine Ann Escanlar | Attorney | Counsel for Azurity Pharmaceuticals, Inc.Search in Eureka ↗ |
| Plaintiff law firm | Saiber LLC | Law Firm | Representing Azurity Pharmaceuticals, Inc.Search in Eureka ↗ |
| Defendant counsel | Dmitry V. Shelhoff | Attorney | Counsel for Aurobindo Pharma, Ltd.Search in Eureka ↗ |
| Defendant counsel | KENNETH CANFIELD | Attorney | Counsel for Aurobindo Pharma, Ltd.Search in Eureka ↗ |
| Defendant counsel | R. Touhey Myer | Attorney | Counsel for Aurobindo Pharma, Ltd.Search in Eureka ↗ |
| Defendant law firm | Kratz & Barry, LLP | Law Firm | Representing Aurobindo Pharma, Ltd.Search in Eureka ↗ |
| Defendant law firm | SHELHOFF CANFIELD & CHIN LLC | Law Firm | Representing Aurobindo Pharma, Ltd.Search in Eureka ↗ |
| Presiding judge | Judge N/A | Judge | New Jersey District CourtSearch in Eureka ↗ |
Official order — verbatim text
The stipulation is notable for what it contains beyond a standard Rule 41 dismissal: the express extinguishment of the 30-month FDA approval stay under 21 U.S.C. § 355(j)(5)(B)(iii) is a substantive commercial term, not merely procedural housekeeping. This provision suggests the parties reached a broader resolution — the public record, however, discloses no licensing terms or exclusivity period. Each party bearing its own costs is consistent with a negotiated exit rather than a concession by either side.
US11638692B2 — vancomycin oral liquid composition and method patents
The seven asserted patents — anchored by US11638692B2 (App. No. US17/965253) and spanning US10959946B2 through US10688046B2 — collectively cover compositions and methods for vancomycin oral liquid formulations. Vancomycin oral liquid is used to treat Clostridioides difficile infections and certain enterococcal infections. The patent family spans application dates from at least US15/126059 through US17/965253, suggesting a multi-continuation strategy designed to maintain exclusivity across successive formulation and method claims.
A seven-patent assertion over a single oral liquid product is strategically significant: it signals that Azurity has constructed overlapping claim layers — likely covering formulation composition, excipient combinations, concentration ranges, stability parameters, and manufacturing methods — to complicate generic entry. For competitors developing oral vancomycin liquid or related antibiotic liquid formulations, each patent in this family requires independent claim analysis, as design-around strategies viable against one patent may not clear related family members.
Should you run an FTO against Azurity’s vancomycin oral liquid patent portfolio?
Any pharmaceutical company — generic or branded — developing an oral vancomycin liquid product, related glycopeptide antibiotic liquid formulations, or compounded antibiotic oral solutions should conduct freedom-to-operate analysis across all seven asserted patents. The without-prejudice dismissal of this case means no patent was invalidated or found non-infringed, leaving the full portfolio in force and enforceable. ANDA filers in particular face the same patent landscape Aurobindo navigated — and the prior litigation provides no judicial shield.
PatSnap Eureka’s FTO Search Agent can map each of the seven patent numbers against your formulation’s composition, excipient profile, and manufacturing process — identifying overlap at the claim level rather than the abstract level. Eureka’s citation analysis also surfaces the prosecution history and prior art landscape for each continuation in this family, helping R&D and regulatory teams understand which claim elements have been amended or distinguished and where design-around opportunities may exist.
Run a freedom-to-operate analysis on US11638692B2 to assess your product’s exposure
Run FTO in Eureka →Similar ANDA vancomycin and oral antibiotic liquid patent cases
Cases below involve ANDA pharmaceutical patent assertions in the District of New Jersey and federal courts covering oral antibiotic liquid formulation technology comparable to this dispute.
What this case signals for the ANDA pharmaceutical patent IP landscape
Hatch-Waxman dismissals that extinguish FDA stays reveal how brand-generic disputes are increasingly resolved outside the courtroom.
Stay extinguishment as a negotiating lever in ANDA settlements
The explicit waiver of the 30-month FDA stay signals that Azurity exchanged a key regulatory right for undisclosed consideration. IP teams monitoring branded pharmaceutical portfolios should treat stay extinguishment clauses as indicators of a likely licensing or co-promotion arrangement running beneath the public record.
Seven patents left judicially untested — a gap for later ANDA filers
With no court ruling on validity or infringement, any subsequent ANDA filer for vancomycin oral liquid must conduct independent freedom-to-operate analysis against all seven Azurity patents. The absence of a merits decision removes potential collateral estoppel defences that would otherwise benefit later challengers.
Azurity v Aurobindo — key questions answered
Azurity asserted seven U.S. patents: US11638692B2, US10959947B2, US10959949B2, US10493028B2, US10959946B2, US10959948B2, and US10688046B2. All are directed to compositions and methods for vancomycin oral liquid formulations and were asserted in response to Aurobindo’s ANDA No. 218130 filing with the FDA.
A without-prejudice dismissal means no final judgment was entered on the merits. Azurity retains the theoretical right to re-file suit on the same seven patents against Aurobindo. However, the concurrent extinguishment of the 30-month FDA approval stay — an irrevocable commercial concession — suggests the parties likely reached a broader arrangement making re-litigation improbable absent a breakdown in any undisclosed agreement.
Under 21 U.S.C. § 355(j)(5)(B)(iii), filing a Hatch-Waxman patent suit automatically triggers a 30-month stay on FDA approval of the ANDA. Azurity’s agreement to extinguish that stay for Aurobindo’s ANDA No. 218130 removes the primary regulatory delay mechanism — allowing FDA review to proceed on its normal timeline. This is a material commercial concession that typically signals a negotiated resolution benefiting the generic filer.
No. The case was dismissed without prejudice by joint stipulation before any merits ruling on validity or infringement was issued. All seven patents remain in force and judicially untested. This means subsequent ANDA filers targeting vancomycin oral liquid formulations cannot rely on any collateral estoppel or judicial finding from this case when challenging these patents.
Azurity was represented by Arnold B. Calmann and Katherine Ann Escanlar of Saiber LLC. Aurobindo was represented by Dmitry V. Shelhoff and Kenneth Canfield of Shelhoff Canfield & Chin LLC, and R. Touhey Myer of Kratz & Barry, LLP.
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