Celgene v. Amneal Pharmaceuticals: Lenalidomide Patent Consent Judgment in 10 Days
Celgene filed suit against Amneal Pharmaceuticals in the District of New Jersey asserting two patents covering polymorphic forms of lenalidomide (Revlimid). The parties resolved the action in just 10 days via a consent judgment that permanently enjoins Amneal from marketing its ANDA product until both patents expire — one of the fastest resolutions on record for a pharmaceutical patent infringement case.
10-day consent judgment locks Amneal out of lenalidomide ANDA market
On 26 January 2024, Celgene Corporation — a Bristol-Myers Squibb subsidiary and originator of the blockbuster multiple myeloma drug Revlimid — filed a patent infringement action in the District of New Jersey against Amneal Pharmaceuticals, Inc., Amneal Pharmaceuticals LLC, and Amneal EU, Limited. The suit asserted two patents, US7855217B2 and US7465800B2, both covering polymorphic forms of 3-(4-amino-1-oxo-1,3 dihydro-isoindol-2-yl)-piperidine-2,6-dione — the active ingredient lenalidomide. The action was triggered by Amneal’s Abbreviated New Drug Application No. 216213, a standard Hatch-Waxman ANDA filing seeking approval to market a generic lenalidomide product in the United States.
The case closed on 5 February 2024 — just 10 days after filing — when the court entered a consent judgment jointly stipulated by both parties. The judgment permanently enjoins all Amneal entities and their successors from making, selling, importing, or distributing the ANDA product in the United States until both patents-in-suit expire, unless specifically authorised by Celgene. All claims and counterclaims were dismissed with prejudice, and no costs or attorneys’ fees were awarded to either party. Critically, the consent judgment preserves Amneal’s Paragraph IV certification rights and its ability to conduct activities protected under 35 U.S.C. § 271(e)(1), suggesting the injunction is structured to delay commercial launch rather than permanently extinguish Amneal’s ANDA entirely.
A 10-day resolution strongly suggests the parties had reached a pre-filing agreement — a pattern common in Hatch-Waxman litigation where brand and generic manufacturers negotiate authorised-generic or launch-date arrangements before formal suit is filed. The public record does not disclose whether any licence, royalty arrangement, or authorised-generic agreement underpins the consent judgment, and no such terms appear in the filed documents. What is clear is that Celgene secured a clean injunction protecting both patents through their respective expiry dates, while Amneal avoided a contested infringement finding and retains the optionality conferred by its Paragraph IV certification.
Filing to settlement in 10 days
Days from filing to consent judgment — exceptionally fast resolution for pharma patent litigation
What the consent judgment means for Celgene and Amneal
Consent judgment: a negotiated court order, not a litigated win
A consent judgment is a court order entered by agreement of both parties — it has the full binding force of a judicial ruling without a contested trial or merits decision. Here, both Celgene and Amneal stipulated to the judgment’s terms, meaning Amneal accepted the injunction voluntarily. This is distinct from a default judgment or a finding of infringement by the court; no court determined that Amneal’s ANDA product actually infringes the patents-in-suit.
Agreed order — no infringement findingClaims dismissed with prejudice — Amneal cannot relitigate these patents
All claims and counterclaims in this action were dismissed with prejudice. This means Amneal cannot bring the same invalidity or non-infringement arguments against these two patents in a future action on this ANDA, and Celgene cannot refile the same infringement claims. The with-prejudice dismissal, combined with the permanent injunction, gives Celgene durable protection. However, Amneal retains its Paragraph IV certification, leaving open the theoretical possibility of challenging the patents via a separate ANDA or IPR proceeding.
With prejudice — no refilingPermanent injunction runs until both patents expire
The injunction blocks Amneal — including successors and assigns — from any commercial activity with ANDA No. 216213 in the United States until US7855217B2 and US7465800B2 both expire. It also extends to any lenalidomide product referencing NDA No. 21-880, meaning Amneal cannot circumvent the injunction by reformulating under the same reference product. Enforcement rights pass to Celgene’s successors, protecting BMS’s commercial position even through future corporate transactions.
US-wide, assignee-binding injunctionAmneal keeps its Paragraph IV certification and research exemption
Two carve-outs in the consent judgment are commercially significant. First, Amneal retains its Paragraph IV certification under 21 U.S.C. § 355(j)(2)(A)(vii)(IV), preserving its ability to challenge patent validity through future proceedings. Second, research and development activities protected by 35 U.S.C. § 271(e)(1) — the so-called safe harbour for pre-approval activities — remain unaffected. The FDA is also explicitly not restricted from approving ANDA No. 216213, meaning approval could issue but commercial launch remains enjoined.
Para IV certification preservedFull party and counsel information
| Role | Name | Type | Detail |
|---|---|---|---|
| Plaintiff | Celgene, Corp. | Company | Pharmaceutical innovator (BMS subsidiary) — holder of US7855217B2 and US7465800B2 covering lenalidomideSearch in Eureka ↗ |
| Defendant | Amneal Pharmaceuticals, Inc. | Company | US generic pharmaceutical manufacturer filing ANDA No. 216213 for a lenalidomide drug productSearch in Eureka ↗ |
| Plaintiff counsel | Charles Michael Lizza | Attorney | Counsel for Celgene, Corp.Search in Eureka ↗ |
| Plaintiff counsel | Sarah Ann Sullvian | Attorney | Counsel for Celgene, Corp.Search in Eureka ↗ |
| Plaintiff counsel | William C. Baton | Attorney | Counsel for Celgene, Corp.Search in Eureka ↗ |
| Presiding judge | Judge / | Chief Judge | New Jersey District Court — Chief JudgeSearch in Eureka ↗ |
Stipulation of dismissal — official text
The consent judgment is a jointly stipulated court order — not a litigated finding of infringement. The court entered the judgment on 5 February 2024 on the parties’ own motion. The operative effect is a permanent, US-wide injunction against Amneal’s ANDA No. 216213 until both patents expire, with no costs awarded to either side. The language preserving Amneal’s Paragraph IV rights and § 271(e)(1) safe harbour is significant: it suggests the parties negotiated boundaries carefully, leaving Amneal with optionality while giving Celgene the commercial protection it sought.
US7855217B2 & US7465800B2 — Polymorphic forms of lenalidomide
US7855217B2 and US7465800B2 both protect polymorphic forms of 3-(4-amino-1-oxo-1,3 dihydro-isoindol-2-yl)-piperidine-2,6-dione — the chemical name for lenalidomide, the active ingredient in Celgene’s Revlimid. Polymorphic patents claim specific crystalline structures of a drug molecule; because different polymorphs can affect solubility, bioavailability, and manufacturability, they are commercially critical and frequently the subject of Hatch-Waxman litigation. The application numbers (US10/934863 and US12/335395) indicate filing dates in the mid-2000s, consistent with the lifecycle of Revlimid’s IP estate. Both patents are listed in the FDA’s Orange Book against NDA No. 21-880.
Lenalidomide is among the highest-revenue oncology drugs ever commercialised, with Revlimid generating peak annual sales exceeding $12 billion globally. Polymorph patents on blockbuster small molecules are among the most litigated IP assets in the pharmaceutical sector because they can extend effective market exclusivity beyond compound patent expiry. For generic manufacturers, any ANDA referencing NDA No. 21-880 must contend with these Orange Book-listed patents — making freedom-to-operate analysis around US7855217B2 and US7465800B2 a prerequisite for any lenalidomide development programme.
Should you run an FTO against US7855217B2 and US7465800B2?
Any company developing, manufacturing, or planning to commercialise a lenalidomide-containing drug product in the United States should treat these two patents as active barriers. The consent judgment confirms Celgene is willing to enforce both aggressively — and quickly. Generic manufacturers with pending or planned ANDAs referencing NDA No. 21-880, as well as companies developing lenalidomide analogues or formulations, should conduct a full FTO analysis to map claim scope against their specific polymorph form and manufacturing process.
PatSnap Eureka’s FTO Search Agent can map the claim landscapes of US7855217B2 and US7465800B2 against your compound’s crystalline characterisation data, identify design-around opportunities, and flag other Orange Book-listed patents in the Revlimid estate that may not be visible in a manual review. Claim monitoring alerts can also track any continuation or divisional applications that could extend the coverage of these polymorph patents beyond their current expiry dates.
Run a freedom-to-operate analysis on US7855217B2 to assess your product’s exposure
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What this case signals for the lenalidomide and Hatch-Waxman IP landscape
A 10-day consent judgment in a blockbuster drug patent case rarely happens without a prior commercial agreement. Here is what that means for IP strategy.
Pre-filing settlement is now standard in Revlimid ANDA litigation
Celgene and BMS have pursued a systematic Hatch-Waxman strategy around lenalidomide, entering consent judgments with multiple ANDA filers. The speed of this resolution — 10 days — is consistent with a negotiated outcome finalised before filing. Companies monitoring the lenalidomide IP landscape should track each consent judgment’s expiry terms, as staggered authorised-generic launch windows can significantly reshape the generic entry timeline.
The injunction’s successor-binding language matters for M&A due diligence
The consent judgment explicitly binds Amneal’s successors and assigns. Any acquirer of Amneal’s generics business or its lenalidomide ANDA would inherit this injunction. In-house teams conducting pharmaceutical M&A due diligence should flag consent judgments of this type as material IP encumbrances — particularly where the target holds multiple ANDAs subject to similar orders covering high-value branded drugs.
Celgene v Amneal — key questions answered
The court entered a consent judgment on 5 February 2024 permanently enjoining Amneal from making, selling, or importing its lenalidomide ANDA product (ANDA No. 216213) in the United States until US7855217B2 and US7465800B2 expire. All claims were dismissed with prejudice and no costs were awarded.
Celgene asserted US7855217B2 and US7465800B2, both covering polymorphic forms of lenalidomide (the active ingredient in Revlimid). Both patents are listed in the FDA Orange Book against NDA No. 21-880. The case was triggered by Amneal’s ANDA No. 216213.
A consent judgment in Hatch-Waxman litigation is a binding court order entered by agreement of both parties — without a contested trial. It typically reflects a pre-negotiated commercial arrangement. Here, it resulted in a permanent injunction against Amneal’s ANDA product while preserving certain rights, including Amneal’s Paragraph IV certification.
The consent judgment preserves Amneal’s Paragraph IV certification under 21 U.S.C. § 355(j)(2)(A)(vii)(IV), which theoretically allows future patent challenges such as IPR petitions at the USPTO. However, all claims in this specific action were dismissed with prejudice, limiting Amneal’s ability to relitigate the same issues in district court under the same ANDA.
A 10-day resolution strongly suggests the parties reached a settlement or commercial agreement before the complaint was filed. This pattern is common in Hatch-Waxman litigation involving high-value branded drugs, where brand manufacturers and ANDA filers frequently negotiate authorised-generic licences or launch-date agreements in parallel with — or in advance of — formal litigation.
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