Celgene & BMS v. Teva & Natco: Onureg® Azacitidine Consent Judgment (259 Days)
Celgene, Celgene International, and Bristol-Myers Squibb secured a consent judgment and injunction against Natco Pharma over two patents protecting Onureg® oral azacitidine tablets, blocking Natco’s ANDA product until both patents expire. The case resolved in 259 days without costs or attorneys’ fees to either side.
BMS/Celgene Lock Out Natco’s Generic Azacitidine via Stipulated Injunction
Filed on 13 September 2023 in the District of Delaware before Judge Jennifer L. Hall, this Hatch-Waxman action was brought by Celgene Corporation, Celgene International SARL, and Bristol-Myers Squibb Company against Teva Pharmaceutical Industries and Natco Pharma Limited. The suit asserted US Patent Nos. 11,571,436 and 8,846,628, both covering oral azacitidine tablet formulations sold under the Onureg® brand, a maintenance therapy approved for acute myeloid leukemia. The trigger was Natco’s ANDA No. 218696 seeking approval to market 200 mg and 300 mg azacitidine tablets in the United States.
The case closed on 29 May 2024 via a consent judgment — a stipulated resolution in which Natco agreed to entry of a permanent injunction without admitting infringement or invalidity. Natco is barred from making, selling, importing, or distributing its ANDA product in the US until expiration of both patents-in-suit. All claims and counterclaims were dismissed with prejudice, and no costs or fees were assessed. Importantly, the consent judgment explicitly preserves Natco’s right to maintain its Paragraph IV certification and to conduct activities permitted under 35 U.S.C. § 271(e)(1), leaving open future challenge pathways.
Resolution in 259 days — well within a typical 30-month Hatch-Waxman stay window — suggests the parties reached commercial alignment before any substantive patent merits were adjudicated. The public record does not disclose whether a licensing arrangement or market entry date was negotiated separately. The injunction’s explicit carve-out preserving FDA approval of the ANDA and Natco’s Paragraph IV rights is a notable drafting choice, consistent with preserving optionality for post-expiry or post-IPR entry scenarios.
Filing to Consent Judgment in 259 days
259 days — faster than median Hatch-Waxman ANDA litigation in Delaware
Consent judgment entered: what the stipulated injunction means for both parties
A consent judgment is a court-entered injunction by agreement
A consent judgment differs from a litigated ruling: both parties stipulate to its terms, and the court enters it as an enforceable order. Here, Natco agreed to an injunction blocking its ANDA product until patent expiry without any finding of infringement or invalidity. All claims were dismissed with prejudice — meaning neither party can re-litigate the same claims in a new action — but the underlying patents remain unchallenged on the merits.
Dismissed with prejudicePlaintiffs secure patent exclusivity through expiry without trial risk
BMS and Celgene obtained the outcome that matters commercially: a court-enforced injunction that prevents Natco’s generic azacitidine product from entering the US market until both patents expire. By resolving pre-trial, they avoided the risk of an invalidity or non-infringement finding on US11571436B2 or US8846628B2. Compliance is enforceable by plaintiffs and their successors, providing durable protection for Onureg® revenues during the remaining patent term.
Injunction until patent expiryNatco enjoined but retains future challenge rights and ANDA approval path
Natco cannot market its ANDA product while both patents remain in force, but the consent judgment was carefully drafted to preserve key rights. Natco may maintain its Paragraph IV certification, allowing it to pursue future patent challenges — including via IPR — and the FDA remains free to approve ANDA No. 218696. Natco also retains safe harbour rights under 35 U.S.C. § 271(e)(1). These carve-outs suggest Natco’s litigation posture may not be permanently resolved.
Para IV & IPR rights preservedOnureg® patent barrier strengthened; AML maintenance therapy market stays protected
For the oral azacitidine and AML maintenance therapy market, this consent judgment reinforces the patent barrier around Onureg®. Other ANDA filers referencing NDA 214120 should note the injunction’s broad scope, which also bars Natco from assisting third parties in infringing the patents-in-suit. Competitors in the space should assess both patents’ expiry timelines and monitor for IPR petitions that could reopen the generic entry window ahead of schedule.
AML therapy market protectedFull party and counsel information
| Role | Name | Type | Detail |
|---|---|---|---|
| Plaintiff | Celgene, Corp. | Company | Pharmaceutical patent holder — BMS/Celgene, holders of US11571436B2 and US8846628B2 covering Onureg® oral azacitidineSearch in Eureka ↗ |
| Co-Plaintiff | Bristol‑Myers Squibb Company | Company | Search in Eureka ↗ |
| Co-Plaintiff | Celgene International, SARL | Individual | Search in Eureka ↗ |
| Defendant | Teva Pharmaceutical Industries, Ltd. | Company | Generic pharmaceutical manufacturer — Natco Pharma seeking US approval for azacitidine tablets via ANDA 218696Search in Eureka ↗ |
| Co-Defendant | Natco Pharma Limited | Individual | Search in Eureka ↗ |
| Plaintiff counsel | Amy K. Wigmore | Attorney | Counsel for Celgene, Corp.Search in Eureka ↗ |
| Plaintiff counsel | Andrew J. Danford | Attorney | Counsel for Celgene, Corp.Search in Eureka ↗ |
| Plaintiff counsel | Brian E. Farnan | Attorney | Counsel for Celgene, Corp.Search in Eureka ↗ |
| Plaintiff counsel | David Mlaver | Attorney | Counsel for Celgene, Corp.Search in Eureka ↗ |
| Plaintiff counsel | Gerard A. Salvatore | Attorney | Counsel for Celgene, Corp.Search in Eureka ↗ |
| Plaintiff counsel | Heather M. Petruzzi | Attorney | Counsel for Celgene, Corp.Search in Eureka ↗ |
| Plaintiff counsel | Joseph J. Farnan , Jr. | Attorney | Counsel for Celgene, Corp.Search in Eureka ↗ |
| Plaintiff counsel | Li-tsung A. Chen | Attorney | Counsel for Celgene, Corp.Search in Eureka ↗ |
| Plaintiff counsel | Michael J. Farnan | Attorney | Counsel for Celgene, Corp.Search in Eureka ↗ |
| Plaintiff counsel | Nora Q.E. Passamaneck | Attorney | Counsel for Celgene, Corp.Search in Eureka ↗ |
| Plaintiff law firm | Farnan LLP | Law Firm | Representing Celgene, Corp.Search in Eureka ↗ |
| Defendant counsel | Elise M. Lecrone | Attorney | Counsel for Teva Pharmaceutical Industries, Ltd.Search in Eureka ↗ |
| Defendant counsel | George C. Lombardi | Attorney | Counsel for Teva Pharmaceutical Industries, Ltd.Search in Eureka ↗ |
| Defendant counsel | Ivan M. Poullaos | Attorney | Counsel for Teva Pharmaceutical Industries, Ltd.Search in Eureka ↗ |
| Defendant counsel | Karen Elizabeth Keller | Attorney | Counsel for Teva Pharmaceutical Industries, Ltd.Search in Eureka ↗ |
| Defendant counsel | Kevin J. Boyle | Attorney | Counsel for Teva Pharmaceutical Industries, Ltd.Search in Eureka ↗ |
| Defendant counsel | Nathan Roger Hoeschen | Attorney | Counsel for Teva Pharmaceutical Industries, Ltd.Search in Eureka ↗ |
| Defendant law firm | Shaw Keller LLP | Law Firm | Representing Teva Pharmaceutical Industries, Ltd.Search in Eureka ↗ |
| Presiding judge | Judge Jennifer L. Hall | Judge | Delaware District CourtSearch in Eureka ↗ |
Official order — verbatim text
The consent judgment is entered by stipulation — neither party litigated to a merits determination. The injunction’s scope is broad, covering Natco’s ANDA product and any third-party assistance in connection with azacitidine products referencing NDA 214120. Critically, the dismissal with prejudice forecloses re-litigation of these specific claims, but the express preservation of Paragraph IV and § 271(e)(1) rights signals that both patents remain potentially vulnerable to post-grant administrative challenges, even as the district court litigation is permanently closed.
US11571436B2 & US8846628B2 — Oral Azacitidine Tablet Formulations (Onureg®)
US11571436B2 (application no. 17/533,033) and US8846628B2 (application no. 12/466,213) are the two patents-in-suit protecting Onureg® (oral azacitidine) — a first-in-class oral hypomethylating agent approved for maintenance therapy in adult patients with AML. The patents cover formulations and methods relating to azacitidine in oral tablet form, a significant technical advance over earlier IV/subcutaneous azacitidine (Vidaza®). The earlier filing date of US8846628B2 (application 2009) reflects long-standing IP investment in this oral delivery technology, while US11571436B2 represents a later continuation capturing refined formulation claims.
These patents are commercially critical because Onureg® represents a meaningful revenue stream for BMS following the Celgene acquisition. The oral formulation patents create a high barrier for generic entry because oral bioavailability of azacitidine requires specific formulation expertise — not merely reformulating an existing IV product. Any generic manufacturer targeting this space must navigate both the formulation claims and the method-of-use claims. The consent judgment’s preservation of Natco’s Paragraph IV rights suggests these patents may face post-grant validity scrutiny, making freedom-to-operate and IPR landscape analysis essential for competitors.
Should you run an FTO against US11571436B2 and US8846628B2?
Any pharmaceutical company developing oral azacitidine generics or novel oral hypomethylating agents for AML or related indications should treat these two patents as high-priority FTO targets. The injunction entered in this case covers not only Natco’s specific ANDA but also any azacitidine product referencing NDA 214120 — and the carve-outs confirm BMS/Celgene will enforce. Even formulation variants that differ from Natco’s 200/300 mg tablets may fall within claim scope depending on claim construction.
PatSnap Eureka’s FTO Search Agent can map the claim boundaries of US11571436B2 and US8846628B2 against your candidate formulation, identify prosecution history estoppel that may limit claim scope, and surface any IPR petitions or ex parte reexaminations filed against these patents. Eureka can also identify the full BMS/Celgene oral azacitidine patent family to ensure no continuation claims are overlooked — a critical step before committing to an ANDA development programme.
Run a freedom-to-operate analysis on US11571436B2 to assess your product’s exposure
Run FTO in Eureka →Similar Hatch-Waxman ANDA cases involving oral oncology formulation patents in Delaware
Explore related Hatch-Waxman ANDA infringement cases in the Delaware District Court involving oral oncology and hypomethylating agent formulation patents.
Related patent case — similar technology
Comparable case in the same technology domain. Patent holder and defendant reached resolution after proceedings.
SettledRelated infringement action — same court
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Active · District CourtRelated invalidity challenge — appellate outcome
Combined invalidity and infringement action in the same technology space. Decided after substantive proceedings.
DecidedCelgene, Corp.’s broader IP enforcement history
Celgene, Corp.’s full litigation history covering prior enforcement, licensing activity, and inter partes review proceedings.
Portfolio viewWhat this case signals for the oral oncology generic drug IP landscape
This consent judgment reinforces BMS/Celgene’s Onureg® exclusivity and sets a precedent for how branded pharma can resolve ANDA challenges efficiently.
Pre-trial consent judgments are a powerful tool for branded pharma patent protection
By securing a stipulated injunction in under 259 days, BMS and Celgene avoided trial risk while locking in patent exclusivity through expiry. For IP teams at branded pharmaceutical companies, this illustrates the value of moving assertively at the ANDA filing stage and negotiating resolution before invalidity arguments are fully developed in litigation.
Preserved Paragraph IV rights mean Natco’s challenge is deferred, not abandoned
The consent judgment’s carve-outs for Paragraph IV certification and § 271(e)(1) safe harbour activity are strategically significant. Natco retains the ability to file IPR petitions against US11571436B2 and US8846628B2 at any time. Companies relying on this injunction for market exclusivity should monitor the USPTO’s IPR docket for any post-grant challenge filings against either patent.
Expiry mapping for US11571436B2 and US8846628B2 is now a commercial priority
Understanding the precise expiry dates and any patent term extensions for both patents-in-suit is essential for generic manufacturers planning market entry strategies. The injunction dissolves at expiry — making accurate term calculation, including PTE/PTA analysis, a high-value intelligence task for any ANDA filer targeting oral azacitidine.
NDA 214120 reference creates a litigation magnet for all future oral azacitidine ANDAs
The injunction explicitly covers any azacitidine product referencing NDA 214120, not just Natco’s specific ANDA. This drafting signals that BMS/Celgene will likely pursue similar consent judgments or full litigation against any subsequent ANDA filer, making this case a template for assessing litigation risk for all oral azacitidine generic entrants.
Celgene v Teva — key questions answered
The asserted patents were US11571436B2 and US8846628B2, both covering oral azacitidine tablet formulations marketed as Onureg®. The case was triggered by Natco’s ANDA No. 218696 seeking to market 200 mg and 300 mg azacitidine tablets in the United States.
Natco is permanently enjoined from marketing its ANDA product in the United States until both patents-in-suit expire. However, the FDA may still approve ANDA 218696, and Natco retains rights to maintain its Paragraph IV certification and to conduct research activities under 35 U.S.C. § 271(e)(1), preserving future challenge options.
Yes. The consent judgment expressly preserves Natco’s right to maintain its Paragraph IV certification and does not restrict activities under the safe harbour provision of 35 U.S.C. § 271(e)(1). This means Natco could file an IPR petition at the USPTO against either US11571436B2 or US8846628B2 — the district court litigation is closed, but post-grant administrative challenges remain available.
The 259-day resolution is consistent with Hatch-Waxman cases that settle before substantive claim construction or expert discovery. The public record does not disclose whether a commercial licensing arrangement accompanied the consent judgment. Resolution before trial eliminated invalidity and non-infringement risk for plaintiffs while potentially securing agreed market-entry terms for Natco.
The injunction directly binds Natco and its successors and assigns. However, paragraph 4 of the consent judgment also enjoins Natco from assisting third parties in infringing the patents in connection with any azacitidine product referencing NDA 214120. Other ANDA filers are not directly bound but face the same patent barrier and should expect similar enforcement actions from BMS/Celgene.
Monitor the oral azacitidine patent landscape before your next ANDA filing
This consent judgment confirms BMS and Celgene will enforce aggressively. Run a full FTO and patent term analysis on US11571436B2 and US8846628B2 in PatSnap Eureka before committing to an oral azacitidine development programme.
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