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AstraZeneca v. Lupin: LOKELMA® Patent Consent Judgment | PatSnap
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Case ID1:23-cv-01189
FiledOct 2023
ClosedMay 2024
Patent Litigation

AstraZeneca v. Lupin: LOKELMA® Patent Infringement Settled by Consent Judgment

ZS Pharma and AstraZeneca filed suit against Lupin in Delaware over 14 patents protecting LOKELMA® (sodium zirconium cyclosilicate), a potassium-lowering therapy. The case resolved in 222 days via a negotiated consent judgment that enjoins Lupin from commercialising its ANDA product unless specifically authorised under the settlement terms.

Resolution time
222days
222 days — resolved well within the 30-month Hatch-Waxman stay window
Patents asserted
1
US11738044B2 and 13 further Licensed Patents asserted covering LOKELMA® formulations
Outcome
Consent Judgment
Consent judgment with injunction; all claims dismissed with prejudice, no costs awarded
Cost ruling
No Costs
Parties agreed: no costs, disbursements, or attorneys’ fees awarded to either side
Published by PatSnap Insights Team · Verified by PatSnap Eureka Data
Case overview

ANDA infringement suit over potassium binder LOKELMA® ends in injunction

On 20 October 2023, ZS Pharma, Inc. and AstraZeneca Pharmaceuticals LP filed a Hatch-Waxman infringement action in the District of Delaware against Lupin Limited and Lupin Pharmaceuticals, Inc., asserting fourteen patents — including US11738044B2 — that collectively protect LOKELMA® (sodium zirconium cyclosilicate) oral suspension. Lupin had filed ANDA No. 217549 seeking FDA approval to market a generic version of the 5 g and 10 g per-packet product.

The case closed on 29 May 2024, just 222 days after filing, via a consent judgment entered by Judge Jennifer L. Hall. Under the judgment, Lupin and its affiliates are enjoined from making, using, selling, offering to sell, importing, or distributing the Lupin ANDA product unless specifically authorised by the underlying Settlement Agreement. All claims and counterclaims were dismissed with prejudice, and neither party was awarded costs or attorneys’ fees.

Resolution within 222 days — well inside the typical 30-month Hatch-Waxman stay period — suggests the parties reached commercial alignment before full Markman or trial proceedings were required. The public record does not disclose the licensed entry date, royalty terms, or any market-exclusivity provisions negotiated in the confidential Settlement Agreement, leaving the precise commercial upside for Lupin unknown.

Case at a glance
Case no.1:23-cv-01189
DefendantLupin Limited
CourtDelaware
JudgeJennifer L. Hall
FiledOctober 20, 2023
ClosedMay 29, 2024
Duration222 days
OutcomeConsent Judgment
Verdict causeInfringement Action
BasisConsent Judgment
Prior Art Intelligence
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Case data sourced from PACER / Delaware District Court via PatSnap Eureka Litigation Intelligence Explore similar cases ↗
Case timeline

Filing to Consent Judgment in 222 days

222 days — resolved well within the 30-month Hatch-Waxman stay window

Case timeline: Complaint filed OCT 20 2023, FEB–MAR — 222 days total Horizontal timeline showing the three key events in ZS Pharma, Inc. v Lupin Limited from filing to resolution. Source: PACER, Delaware District Court. OCT 20 2023 Complaint filed Pre-trial proceedings MAY 29 2024 Consent Judgment 222 DAYS TOTAL
Settlement terms

Consent judgment with injunction: what the settlement means for both sides

Legal mechanism

Consent judgment is more than a dismissal — it is a court order

Unlike a voluntary dismissal, a consent judgment is a binding court decree. Lupin is formally enjoined by Judge Hall’s order, not merely by private contract. This means AstraZeneca can seek contempt proceedings in Delaware if Lupin commercialises its ANDA product outside the Settlement Agreement’s authorised terms — a materially stronger enforcement position than contract litigation alone.

Enforceable injunction
Patent holder outcome

AstraZeneca secures injunction across all 14 Licensed Patents

The consent judgment names all fourteen Licensed Patents and enjoins Lupin and its affiliates from any commercialisation activity not explicitly permitted under the Settlement Agreement. AstraZeneca retains LOKELMA® market exclusivity under court order. The ‘with prejudice’ dismissal forecloses Lupin from re-litigating the same infringement claims, and the court retains jurisdiction to supervise compliance — giving AstraZeneca a durable enforcement hook.

Market exclusivity protected
Generic challenger outcome

Lupin gains a structured path — but only on AstraZeneca’s terms

Lupin is currently enjoined from launching its ANDA product. However, the Settlement Agreement likely contains a confidential authorised-entry date — standard practice in Hatch-Waxman consent judgments. Lupin’s future LOKELMA® generic launch, if any, is therefore contractually gated. The ‘with prejudice’ dismissal also closes Lupin’s counterclaims, meaning it cannot separately challenge patent validity in this forum.

Entry date likely negotiated
Commercial implications

Fourteen-patent fortress signals strong LOKELMA® lifecycle management

AstraZeneca’s assertion of fourteen patents — spanning formulations, methods of use, and potentially dosage forms — reflects a classic lifecycle-management strategy around a branded oral suspension. Any competitor filing an ANDA for sodium zirconium cyclosilicate must navigate this portfolio. The consent judgment with injunction raises the practical barrier for subsequent ANDA filers, who now face both Orange Book-listed patents and a judicial precedent of AstraZeneca’s willingness to litigate promptly.

High barrier for follow-on ANDAs
Legal analysis based on PACER docket records for case 1:23-cv-01189 and PatSnap Eureka litigation intelligence Search PatSnap Eureka ↗
Parties and representation

Full party and counsel information

RoleNameTypeDetail
PlaintiffZS Pharma, Inc.CompanyPharmaceutical innovator — co-holder of 14 LOKELMA® sodium zirconium cyclosilicate patentsSearch in Eureka ↗
Co-PlaintiffAstrazeneca Pharmaceuticals, LPCompanySearch in Eureka ↗
DefendantLupin LimitedIndividualLupin Limited and Lupin Pharmaceuticals, Inc. — generic pharmaceutical manufacturer, ANDA filerSearch in Eureka ↗
Co-DefendantLupin Pharmaceuticals, Inc.CompanySearch in Eureka ↗
Plaintiff counselAlexandra M. JoyceAttorneyCounsel for ZS Pharma, Inc.Search in Eureka ↗
Plaintiff counselDaniel M. SilverAttorneyCounsel for ZS Pharma, Inc.Search in Eureka ↗
Plaintiff counselGyuhyun (joanne) BaeAttorneyCounsel for ZS Pharma, Inc.Search in Eureka ↗
Plaintiff counselHassen SayeedAttorneyCounsel for ZS Pharma, Inc.Search in Eureka ↗
Plaintiff counselJames Yi LiAttorneyCounsel for ZS Pharma, Inc.Search in Eureka ↗
Plaintiff counselMark A. HaydenAttorneyCounsel for ZS Pharma, Inc.Search in Eureka ↗
Plaintiff law firmMcCarter & English LLPLaw FirmRepresenting ZS Pharma, Inc.Search in Eureka ↗
Defendant counselDavid A. BilsonAttorneyCounsel for Lupin LimitedSearch in Eureka ↗
Defendant counselJohn C. Phillips , Jr.AttorneyCounsel for Lupin LimitedSearch in Eureka ↗
Defendant counselKurt A. MathasAttorneyCounsel for Lupin LimitedSearch in Eureka ↗
Defendant law firmPhillips, Goldman, McLaughlin & Hall PALaw FirmRepresenting Lupin LimitedSearch in Eureka ↗
Presiding judgeJudge Jennifer L. HallJudgeDelaware District CourtSearch in Eureka ↗
Official verdict

Official order — verbatim text

“ZS Pharma, Inc. and AstraZeneca Pharmaceuticals LP (hereinafter collectively “AstraZeneca”), and Lupin Limited and Lupin Pharmaceuticals, Inc. (hereinafter “Lupin”), the parties in the above-captioned actions, have agreed to terms and conditions representing a negotiated settlement of the action and have set forth those terms and conditions in a Settlement Agreement (the “Settlement Agreement”). Now the parties, by their respective undersigned attorneys, hereby stipulate and consent to entry of judgment and an injunction in the action, as follows: IT IS this ______ day of ______, 2024: ORDERED, ADJUDGED AND DECREED as follows: 1. This District Court has jurisdiction over the subject matter of the above actions and has personal jurisdiction over the parties. 2. As used in this Consent Judgment, (i) the term “Lupin Product” shall mean the drug product sold, offered for sale or distributed pursuant to Abbreviated New Drug 29th May Case 1:23-cv-01189-JLH Document 19-1 Filed 05/29/24 Page 1 of 3 PageID #: 113 2 ME1 48578180v.1 Application No. 217549 (and defined in greater detail in the Settlement Agreement); (ii) the term “Licensed Patents” shall mean United States Patent Numbers 8,802,152; 8,808,750; 8,877,255; 9,592,253; 9,844,567; 9,861,658; 9,913,860; 10,300,087; 10,335,432; 10,398,730; 10,413,569; 10,695,365; 11,406,662 and 11,738,044; and (iii) the term “Affiliate” shall mean any entity or person that, directly or indirectly through one or more intermediaries, controls, is controlled by, or is under common control with Lupin; for purposes of this definition, “control” means (a) ownership, directly or through one or more intermediaries, of (1) more than fifty percent (50%) of the shares of stock entitled to vote for the election of directors, in the case of a corporation, or (2) more than fifty percent (50%) of the equity interests in the case of any other type of legal entity or status as a general partner in any partnership, or (b) any other arrangement whereby an entity or person has the right to elect a majority of the Board of Directors or equivalent governing body of a corporation or other entity or the right to direct the management and policies of a corporation or other entity. 3. Unless otherwise specifically authorized pursuant to the Settlement Agreement, Lupin, including any of its Affiliates, successors and assigns, is enjoined from infringing the Licensed Patents, on its own part or through any Affiliate, by making, having made, using, selling, offering to sell, importing or distributing of the Lupin Product. 4. Compliance with this Consent Judgment may be enforced by AstraZeneca and its successors in interest, or assigns, as permitted by the terms of the Settlement Agreement. 5. This District Court retains jurisdiction to enforce or supervise performance under this Consent Judgment and the Settlement Agreement. Case 1:23-cv-01189-JLH Document 19-1 Filed 05/29/24 Page 2 of 3 PageID #: 114 3 ME1 48578180v.1 6. All claims, counterclaims, affirmative defenses and demands in this action are hereby dismissed with prejudice and without costs, disbursements or attorneys’ fees to any party.”
Source: PACER Docket, Case 1:23-cv-01189, Delaware District Court

The consent judgment is unusually detailed for a settlement instrument: it defines ‘Lupin Product’, ‘Licensed Patents’, and ‘Affiliate’ with precision, and the injunction tracks the language of 35 U.S.C. § 271 verbatim — making, using, selling, offering to sell, importing, and distributing. The ‘with prejudice’ dismissal of all claims and counterclaims is significant: Lupin cannot revive invalidity or non-infringement arguments in this court. The court’s retention of jurisdiction to supervise compliance transforms this from a private contract into an enforceable judicial order.

PACER case 1:23-cv-01189 · Public docket record Explore in Eureka ↗
Patent at issue

US11738044B2 — sodium zirconium cyclosilicate oral suspension formulation

Publication No.US11738044B2
Application No.US16/415550
Patent details
ProductSodium zirconium cyclosilicate oral suspension for potassium management (LOKELMA®)
Cited in actionOctober 20, 2023

US11738044B2 (application no. US16/415,550) is one of fourteen Licensed Patents protecting LOKELMA® (sodium zirconium cyclosilicate), an inorganic cation exchanger indicated for hyperkalaemia (high potassium). The patent sits in a portfolio spanning at least US8,802,152 through US11,738,044, suggesting layered protection across formulation composition, particle engineering, dosage forms, and methods of treatment. The 5 g and 10 g per-packet oral suspension format is the specific ANDA-challenged product.

LOKELMA® competes in the potassium binder category alongside patiromer (Veltassa®). AstraZeneca’s fourteen-patent portfolio creates significant lifecycle protection, with later-filed patents such as US11738044B2 potentially extending exclusivity well beyond the original composition claims. For generic manufacturers, this stacked portfolio represents a multi-front validity and infringement challenge — and the consent judgment demonstrates that AstraZeneca is prepared to litigate all fourteen patents simultaneously against a single ANDA filer.

Patent data sourced from USPTO via PatSnap Eureka patent database Search patent records in Eureka ↗
Freedom to operate

Should you run an FTO against LOKELMA®’s sodium zirconium cyclosilicate patents?

Any pharmaceutical company developing or filing an ANDA for sodium zirconium cyclosilicate oral suspension must assess freedom-to-operate across all fourteen Licensed Patents, not only US11738044B2. R&D and regulatory teams evaluating hyperkalaemia treatments — or novel potassium-binding formulations — should determine whether their process, formulation, or dosage form falls within claims across this portfolio. A single unanalysed patent can result in a consent-judgment-level injunction, as this case illustrates.

PatSnap Eureka’s FTO Search Agent allows you to map your compound or formulation against the full AstraZeneca/ZS Pharma LOKELMA® portfolio in minutes. Run claim-by-claim comparison across all 14 Licensed Patents, identify design-around opportunities, and flag expiry timelines — giving your IP and product teams a defensible clearance record before ANDA filing or product launch.

PatSnap Eureka FTO Search

Run a freedom-to-operate analysis on US11738044B2 to assess your product’s exposure

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Related litigation

Similar Hatch-Waxman ANDA infringement cases in Delaware District Court

Cases involving branded oral suspension patents, multi-patent ANDA challenges, and consent judgment resolutions in Delaware District Court — the primary venue for Hatch-Waxman litigation.

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Strategic implications

What this case signals for the potassium binder and ANDA IP landscape

AstraZeneca’s rapid settlement-with-injunction sets a clear enforcement benchmark for LOKELMA® and similar branded oral suspension portfolios.

Swift resolution inside the 30-month stay is a deliberate Hatch-Waxman strategy

By resolving in 222 days, AstraZeneca avoided expensive Markman and trial proceedings while still securing a court-ordered injunction. For branded pharmaceutical companies, early settlement with a consent judgment — rather than dismissal — preserves enforcement optionality at lower litigation cost. Generic filers should expect this playbook when a branded portfolio covers fourteen or more patents.

Fourteen-patent assertion means any LOKELMA® ANDA faces a wide-net challenge

The Licensed Patents span multiple US patent numbers, likely covering formulation, particle size, dosage, and method-of-use claims for sodium zirconium cyclosilicate. A competitor cannot design around a single patent and expect clearance. IP teams evaluating entry into the potassium binder space should conduct FTO analysis across the full portfolio — not just the lead patent listed on the ANDA.

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Full strategic analysis in PatSnap Eureka
Unlock gated insights on LOKELMA® patent expiry timing, 180-day exclusivity risk, and ANDA entry strategy for this Delaware District Court case.
Licensed entry date signalsFirst-filer exclusivity riskPatent expiry runway analysis
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Frequently asked questions

ZS v Lupin — key questions answered

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Track LOKELMA® patent expiries and ANDA activity before your next filing

PatSnap Eureka lets you monitor all fourteen LOKELMA® Licensed Patents, track Lupin and competitor ANDA activity, and run automated FTO searches across the sodium zirconium cyclosilicate portfolio. Stay ahead of the next consent judgment.

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