American Regent v. RK Pharma: Selenious Acid Patent Consolidated into 13-Defendant ANDA Battle
American Regent, Inc. filed suit against RK Pharma, Inc. in the District of New Jersey asserting US11998565B2, covering injectable selenious acid formulations used for selenium supplementation. The case was consolidated within 128 days into a landmark multi-defendant action spanning 13 generic challengers — one of the broadest ANDA consolidations in recent pharmaceutical litigation.
Broad ANDA sweep: American Regent corrals 13 generic rivals in NJ federal court
On July 16, 2024, American Regent, Inc. filed this infringement action against RK Pharma, Inc. in the U.S. District Court for the District of New Jersey, asserting U.S. Patent No. 11,998,565 B2 (application no. US18/124391). The asserted patent covers selenious acid injectable formulations — specifically ARI’s selenium supplement products dosed at 600 mcg/10 mL, 60 mcg/mL, and 12 mcg/2 mL concentrations — which are used for parenteral selenium supplementation in clinical settings.
The case terminated on November 21, 2024, not through a merits ruling but via consolidation. By stipulation of all parties, this docket and 12 parallel actions filed by American Regent against separate generic manufacturers — including Accord Healthcare, Cipla, Dr. Reddy’s, Hikma, Sun Pharma, and Zydus, among others — were consolidated under lead case No. 2:24-cv-7791. All future filings now proceed under that single caption. The consolidation is a procedural step and does not constitute any finding on validity, infringement, or liability.
The 128-day timeline from filing to consolidation is consistent with standard ANDA litigation consolidation practice, where courts and parties routinely streamline overlapping Hatch-Waxman suits to avoid duplicative discovery and inconsistent rulings. The breadth of the defendant roster — 13 generic manufacturers simultaneously challenging the same patent — suggests US11998565B2 covers a commercially significant formulation facing widespread generic ANDA filings. What remains unknown from the public record is the precise ANDA filing dates, Paragraph IV certification details, and the 30-month stay status that will govern the consolidated proceeding’s litigation pace.
Filing to Case Consolidated in 128 days
128 days from filing to consolidation — resolved procedurally before merits phase
Case consolidated: what the transfer to lead docket means for both parties
Consolidation is procedural — the patent fight continues
Consolidation under Fed. R. Civ. P. 42(a) merges related actions sharing common questions of law or fact into a single proceeding. This docket’s closure reflects an administrative transfer to lead case 2:24-cv-7791, not a resolution on the merits. US11998565B2’s validity and infringement remain fully contested. RK Pharma’s liability exposure — and ARI’s enforcement position — carries forward unchanged into the consolidated action.
No merits ruling issuedARI gains efficiency — and a unified litigation front
Consolidation typically benefits the patent holder in multi-defendant ANDA cases by concentrating resources in a single proceeding, reducing duplicative briefing, and enabling consistent claim construction rulings. American Regent now litigates US11998565B2 once against all 13 generic challengers simultaneously. A favorable claim construction or validity ruling in the consolidated case would bind all defendants, potentially securing broader market protection than piecemeal litigation.
ARI’s position preservedRK Pharma joins a coordinated generic defense pool
For RK Pharma, consolidation means shared discovery and coordinated invalidity strategy alongside well-resourced co-defendants including Cipla, Dr. Reddy’s, Sun Pharma, and Hikma. This can reduce individual litigation cost but also limits independent tactical flexibility. RK Pharma is represented by Sterne Kessler Goldstein & Fox — a specialist ANDA firm — suggesting a substantive invalidity or non-infringement defense is likely being prepared for the consolidated forum.
Defense strategy now coordinatedSelenium injectable market faces prolonged uncertainty
With 13 generic manufacturers simultaneously contesting the same selenium formulation patent, the injectable selenium supplement market is in a holding pattern. Generic market entry depends on the outcome of the consolidated litigation and any operative 30-month Hatch-Waxman stay. Formulary planners, hospital procurement teams, and compounding pharmacies tracking selenium parenteral supply should monitor the lead docket 2:24-cv-7791 for Markman hearing scheduling and any early resolution signals.
13-way ANDA contest ongoingFull party and counsel information
| Role | Name | Type | Detail |
|---|---|---|---|
| Plaintiff | American Regent, Inc. | Company | Pharmaceutical manufacturer — holder of US11998565B2 covering injectable selenious acid formulationsSearch in Eureka ↗ |
| Defendant | RK PHARMA, INC. | Company | Generic pharmaceutical company; ANDA filer challenging ARI’s selenious acid formulation patentSearch in Eureka ↗ |
| Plaintiff counsel | Charles H. Chevalier | Attorney | Counsel for American Regent, Inc.Search in Eureka ↗ |
| Plaintiff counsel | Christine A. Gaddis | Attorney | Counsel for American Regent, Inc.Search in Eureka ↗ |
| Plaintiff law firm | Gibbons PC | Law Firm | Representing American Regent, Inc.Search in Eureka ↗ |
| Defendant counsel | Dennies Varughese | Attorney | Counsel for RK PHARMA, INC.Search in Eureka ↗ |
| Defendant counsel | Eric I. Abraham | Attorney | Counsel for RK PHARMA, INC.Search in Eureka ↗ |
| Defendant counsel | Kristine L. Butler | Attorney | Counsel for RK PHARMA, INC.Search in Eureka ↗ |
| Defendant counsel | William Murtha | Attorney | Counsel for RK PHARMA, INC.Search in Eureka ↗ |
| Defendant law firm | Hill Wallack, LLP | Law Firm | Representing RK PHARMA, INC.Search in Eureka ↗ |
| Defendant law firm | Sterne Kessler Goldstein & Fox | Law Firm | Representing RK PHARMA, INC.Search in Eureka ↗ |
| Presiding judge | Judge N/A | Judge | New Jersey District CourtSearch in Eureka ↗ |
Official order — verbatim text
The stipulated consolidation order recites all 13 parallel actions filed by American Regent and confirms that ‘good cause exists to consolidate.’ This language is formulaic and carries no substantive finding on infringement or validity. The order operates purely as a docket management instrument under Rule 42(a). For both parties, rights and defences are fully preserved in the lead action 2:24-cv-7791. The consolidation is notable for its breadth — 13 defendants, single patent — which is consistent with a coordinated, industry-wide ANDA challenge to a commercially valuable injectable formulation.
US11998565B2 — Injectable Selenious Acid Formulations for Parenteral Selenium Supplementation
U.S. Patent No. 11,998,565 B2, filed under application number US18/124391, protects American Regent’s selenious acid injectable products used to deliver selenium parenterally in clinical settings. The patent covers specific concentration formulations — including 600 mcg selenium per 10 mL, 60 mcg/mL, and 12 mcg/2 mL presentations — used in total parenteral nutrition (TPN) and critical care contexts where oral selenium supplementation is not feasible. The late application number suggests a relatively recent grant, potentially covering formulation-specific innovations in dosing, stability, or manufacturing process.
Injectable selenium formulations occupy a niche but medically essential segment of the parenteral nutrition market. Selenium deficiency in critically ill patients is clinically significant, making this product category a procurement staple for hospital and ICU formularies. The fact that 13 generic manufacturers have simultaneously filed ANDAs indicates substantial commercial volume and an expectation that generic entry would be commercially viable. For innovator companies with competing injectable micronutrient portfolios, this patent represents a potential blocking position across the selenious acid subcategory of the parenteral nutrition space.
Should your team run an FTO analysis against US11998565B2?
Any company developing, manufacturing, or commercialising injectable selenious acid formulations — particularly those targeting TPN applications or critical care selenium supplementation — should treat US11998565B2 as a live enforcement risk. The patent is actively litigated across 13 defendants simultaneously, confirming ARI’s intent to enforce broadly. ANDA filers already in the crosshairs need a clear non-infringement or invalidity position before the consolidated Markman hearing locks in claim scope.
PatSnap Eureka’s FTO Search Agent can map the claims of US11998565B2 against your formulation parameters, flag prior art relevant to selenious acid concentration ranges, and surface the full prosecution history to identify claim scope limitations. For procurement and regulatory teams monitoring generic entry timelines, Eureka’s litigation tracking module provides real-time docket updates on lead case 2:24-cv-7791 — enabling proactive supply chain planning ahead of any stay expiry or settlement.
Run a freedom-to-operate analysis on US11998565B2 to assess your product’s exposure
Run FTO in Eureka →Similar ANDA Patent Infringement Cases in the NJ District Court: Parenteral Formulations
Explore multi-defendant ANDA consolidation cases in the District of New Jersey involving injectable pharmaceutical formulation patents similar to US11998565B2.
What this case signals for the injectable pharmaceutical IP landscape
A 13-defendant ANDA consolidation over a single selenium formulation patent is a rare event — and a strategic signal worth parsing closely.
Multi-defendant ANDA filings signal high commercial value of the target patent
When 13 separate generic manufacturers simultaneously file ANDAs against a single branded formulation, it typically indicates a commercially significant product with meaningful market size. US11998565B2’s selenious acid formulations attract this volume of challenge, suggesting generic entrants see a viable path to market — and ARI has substantial revenue at stake in the consolidated defence.
Consolidation shifts litigation economics — monitor lead docket for case pace
Consolidation under a single judge concentrates claim construction into one Markman hearing that binds all 13 defendants. The outcome of that hearing will be the pivotal event. IP teams tracking this space should docket the lead case 2:24-cv-7791 and watch for scheduling orders — the Markman date will be the clearest signal of litigation trajectory.
American v RK — key questions answered
The case was consolidated, not decided on the merits. On November 21, 2024, by stipulation of all parties, this action was merged into lead case 2:24-cv-7791 along with 12 other parallel ANDA suits filed by American Regent against different generic manufacturers. No finding of infringement or invalidity was made in this docket.
American Regent asserts U.S. Patent No. 11,998,565 B2 (application no. US18/124391), covering injectable selenious acid formulations for parenteral selenium supplementation at specific concentrations including 600 mcg/10 mL, 60 mcg/mL, and 12 mcg/2 mL.
American Regent filed 13 separate infringement suits in the District of New Jersey against different generic manufacturers all challenging the same patent over the same product. Consolidation under Fed. R. Civ. P. 42(a) merges them into one proceeding to avoid duplicative discovery and inconsistent rulings. All merits issues — validity, infringement, damages — continue in lead case 2:24-cv-7791.
RK Pharma is represented by Hill Wallack, LLP and Sterne Kessler Goldstein & Fox. Sterne Kessler is a specialist ANDA and PTAB litigation firm, which typically suggests a substantive invalidity strategy — potentially including inter partes review at the USPTO — in addition to district court non-infringement arguments.
US11998565B2 covers injectable selenious acid formulations used in clinical selenium supplementation, particularly for TPN patients. The simultaneous ANDA challenge by 13 generic manufacturers suggests meaningful commercial volume. A patent holder victory in the consolidated litigation would sustain ARI’s market exclusivity; generic success would open the market to multiple lower-cost competitors, affecting hospital formulary procurement across the US.
PatSnap Eureka searches patents and litigation data to answer instantly.