American Regent v. Fresenius Kabi: Selenious Acid Consent Judgment in 141 Days
American Regent, Inc. filed suit against Fresenius Kabi USA in the District of Delaware, asserting US11998565B2 against Fresenius’s ANDA-based selenious acid injection. The parties resolved the dispute in 141 days through a consent judgment that enjoins Fresenius from commercialising its ANDA product without authorisation, while preserving FDA approval rights.
ANDA Selenium Injection Dispute Ends in Injunction and Settlement
American Regent, Inc. (ARI) filed this Hatch-Waxman infringement action on 16 July 2024 in the U.S. District Court for the District of Delaware before Judge Maryellen Noreika. ARI asserted US11998565B2 against Fresenius Kabi USA, LLC’s Abbreviated New Drug Application No. 218779, which covers a selenious acid injection product equivalent to ARI’s marketed selenium formulations used in parenteral nutrition.
The case closed on 4 December 2024 via a stipulated consent judgment. Under the judgment, Fresenius is enjoined from making, using, selling, offering for sale, importing, or distributing its ANDA product in the United States without ARI’s authorisation under the referenced Settlement Agreement. All claims and counterclaims were dismissed without prejudice and without any cost award to either party, consistent with a negotiated commercial resolution.
Resolution in 141 days is notably fast for an ANDA patent case, which typically proceeds through at least one round of claim construction before settlement pressure builds. The speed here — combined with the consent judgment structure and retained paragraph IV certification rights for Fresenius — suggests the parties reached a licensing or market-entry date agreement in parallel. The private Settlement Agreement governs the precise terms; those commercial details remain outside the public record.
Filing to Consent Judgment in 141 days
141 days — well below the median ANDA patent trial timeline, suggesting early settlement alignment
Consent judgment and injunction: what the resolution means for both parties
Consent judgment injects court authority into a private deal
A consent judgment converts the parties’ private Settlement Agreement into a court order, giving ARI an enforceable injunction without a full trial. The District Court expressly retains jurisdiction to supervise compliance. This is standard ANDA settlement architecture: it resolves the litigation while embedding commercial terms in a non-public agreement referenced but not disclosed in the judgment.
Consent judgment / injunctionARI secures injunction protecting ‘565 Patent market position
American Regent obtains a court-ordered injunction barring Fresenius from commercialising ANDA No. 218779 without ARI’s authorisation. The ‘565 Patent’s enforceability is not challenged on the public record — no invalidity finding was made and claims were dismissed without prejudice, preserving ARI’s ability to enforce against future infringers. Any authorised market entry by Fresenius will be governed by the private Settlement Agreement.
Patent enforceability preservedFresenius retains ANDA and paragraph IV certification rights
Despite the injunction, Fresenius keeps ANDA No. 218779 intact and retains the right to maintain or file paragraph IV certifications against the ‘565 Patent — including on recertification. The 30-month stay is expressly terminated, allowing FDA to grant final ANDA approval. This preserves Fresenius’s optionality for a licensed or future entry, consistent with a negotiated launch date arrangement.
ANDA and para. IV rights retainedSettlement sets a precedent for selenium IV formulation disputes
The rapid resolution and injunction structure suggest ARI successfully defended its selenium injection franchise while offering Fresenius a negotiated path to market. For other ANDA filers targeting selenious acid formulations, this case signals ARI’s willingness to enforce the ‘565 Patent aggressively and its ability to convert early enforcement into consent judgments. Competitors should assess their own ANDA strategies against ARI’s patent estate.
Parenteral nutrition IP risk elevatedFull party and counsel information
| Role | Name | Type | Detail |
|---|---|---|---|
| Plaintiff | American Regent, Inc. | Company | Pharmaceutical company — holder of US11998565B2 covering selenious acid injection formulationsSearch in Eureka ↗ |
| Defendant | Fresenius Kabi | Individual | Generic pharmaceutical manufacturer pursuing ANDA No. 218779 for selenious acid injectionSearch in Eureka ↗ |
| Plaintiff counsel | Christopher Viceconte | 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 | Daniel P. Withers | Attorney | Counsel for Fresenius KabiSearch in Eureka ↗ |
| Defendant counsel | Jieun Lee | Attorney | Counsel for Fresenius KabiSearch in Eureka ↗ |
| Defendant counsel | John C. Phillips , Jr. | Attorney | Counsel for Fresenius KabiSearch in Eureka ↗ |
| Defendant counsel | Megan C. Haney | Attorney | Counsel for Fresenius KabiSearch in Eureka ↗ |
| Defendant counsel | Michael K. Nutter | Attorney | Counsel for Fresenius KabiSearch in Eureka ↗ |
| Defendant law firm | Phillips, McLaughlin & Hall PA | Law Firm | Representing Fresenius KabiSearch in Eureka ↗ |
| Presiding judge | Judge Maryellen Noreika | Judge | Delaware District CourtSearch in Eureka ↗ |
Official order — verbatim text
The consent judgment’s language is carefully structured to protect both parties’ interests. ARI obtains a broad injunction covering all commercialisation activity by Fresenius and its affiliates, while Fresenius preserves its ANDA, paragraph IV rights, and FDA approval pathway. The dismissal without prejudice — rather than with prejudice — is notable: it leaves open the possibility of future enforcement actions and does not concede invalidity. The court’s retention of jurisdiction signals that compliance disputes could return to Judge Noreika without re-filing.
US11998565B2 — Selenious Acid Injection Formulations for Parenteral Use
US11998565B2, filed under application number US18/124391, protects formulations of selenious acid used as an intravenous selenium supplement in parenteral nutrition. Selenium is an essential trace element; selenious acid injections are administered to patients who cannot receive adequate nutrition orally. The patent’s claim scope — likely directed to specific concentration ranges, formulation parameters, or preparation methods — provides ARI with exclusivity over the precise selenium dosing configurations described in its marketed products.
For the parenteral nutrition sector, this patent represents a commercially significant barrier to generic entry in the selenium IV supplement market. ARI’s three marketed dosage strengths (60 mcg/mL and 6 mcg/mL formulations) are directly covered by the asserted patent, and the enforcement action confirms ARI’s intent to police ANDA filings aggressively. Competitors in the IV trace element and specialty injectables space should treat this patent as a live enforcement risk and evaluate their own formulation strategies accordingly.
Should you run an FTO against US11998565B2 before advancing your selenious acid ANDA?
Any generic or specialty pharmaceutical company with an active or planned ANDA, 505(b)(2), or NDA targeting selenious acid injection products — particularly those with selenium concentrations equivalent to 60 mcg/mL or 6 mcg/mL — should treat US11998565B2 as a material FTO risk. This case demonstrates ARI will file suit promptly upon ANDA submission and pursue consent judgments that carry court-enforceable injunctions.
PatSnap Eureka’s FTO Search Agent can map the claim scope of US11998565B2 against your proposed formulation parameters, identify prosecution history disclaimers that may narrow the claims, and surface prior art relevant to any IPR petition strategy. Eureka’s patent landscape tools can also identify the full breadth of ARI’s selenium and parenteral nutrition IP estate, giving your team a complete picture before committing to development or regulatory spend.
Run a freedom-to-operate analysis on US11998565B2 to assess your product’s exposure
Run FTO in Eureka →Similar ANDA Patent Cases: Parenteral Nutrition & Selenium Injection IP
Explore comparable Hatch-Waxman infringement actions in the Delaware District Court involving parenteral nutrition and IV trace element formulation patents.
What this case signals for the parenteral nutrition IP landscape
ARI’s rapid enforcement and consent judgment outcome reveal a hardening IP posture in the selenium IV formulation space.
Consent judgments in ANDA cases carry real enforcement teeth
By converting a private settlement into a court order, ARI can pursue contempt proceedings — not just breach of contract claims — if Fresenius launches without authorisation. ANDA defendants should carefully review the scope of any proposed consent judgment language before signing.
Speed of resolution suggests licensed entry, not capitulation
141-day resolution without any invalidity ruling or cost award strongly suggests a negotiated launch date rather than Fresenius conceding the patent’s validity. The retained paragraph IV certification rights reinforce this reading. The commercial terms in the private Settlement Agreement are the key unknown.
American v Fresenius — key questions answered
The case resolved on 4 December 2024 via a consent judgment and injunction. Fresenius Kabi is enjoined from commercialising ANDA No. 218779 (selenious acid injection) without ARI’s authorisation. All claims were dismissed without prejudice and without cost awards. The private Settlement Agreement governs commercial terms.
American Regent asserted US11998565B2, filed under application number US18/124391, which covers selenious acid injection formulations used in parenteral nutrition as an intravenous selenium supplement. The patent was asserted against Fresenius’s ANDA No. 218779 product.
Yes. The consent judgment expressly terminates any 30-month stay on FDA approval of ANDA No. 218779 and confirms nothing in the judgment prohibits FDA from granting final approval. Fresenius also retains the right to maintain or file paragraph IV certifications against the ‘565 Patent. Any authorised commercial launch is governed by the private Settlement Agreement.
Dismissal without prejudice means the underlying patent infringement claims could theoretically be re-filed if a future dispute arises. In this context, it also confirms no invalidity finding was made against US11998565B2 — the patent’s validity remains unchallenged on the public record, preserving ARI’s ability to enforce it against other generic entrants.
141 days is notably fast for Hatch-Waxman litigation, which typically runs 18–30 months to trial. The rapid resolution, combined with the retained paragraph IV rights and terminated 30-month stay, suggests the parties reached a negotiated commercial agreement — likely a licensed launch date — in parallel with the litigation. The private Settlement Agreement terms are not public.
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