Litigation Details for HORIZON MEDICINES LLC v. TORRENT PHARMA INC. (D.N.J. 2021)

HORIZON MEDICINES LLC v. TORRENT PHARMA INC. (D.N.J. 2021)

Docket		Date Filed	2021-07-07
Court	District Court, D. New Jersey	Date Terminated	2021-12-14
Cause	35:271 Patent Infringement	Assigned To	Stanley R. Chesler
Jury Demand	None	Referred To	Cathy L. Waldor
Patents	8,067,033; 8,067,451; 8,309,127; 8,318,202; 8,449,910; 8,501,228
Link to Docket	External link to docket

Details for HORIZON MEDICINES LLC v. TORRENT PHARMA INC. (D.N.J. 2021)

Date Filed	Document No.	Description	Snippet	Link To Document
2021-07-07				External link to document
2021-07-07	1	Complaint	United States Patent Nos. 8,067,033 (“the ’033 patent”), 8,067,451 (“the ’451 patent”), 8,309,127 (…910 and ’228 patents. COUNT I FOR INFRINGEMENT OF U.S. PATENT NO. 8,067,033 34… (“the ’127 patent”), 8,318,202 (“the ’202 patent”), 8,449,910 (“the ’910 patent”), and 8,501,228 (“…. This is an action for patent infringement arising under the patent laws of the United States,…(“the ’228 patent”) (collectively, the “Asserted Patents”), which cover DUEXIS® and its use.	External link to document

Horizon Medicines LLC v. Torrent Pharma Inc. Patent Litigation Summary, Case No. 2:21-cv-13396

Last updated: September 9, 2026

Horizon Medicines LLC sued Torrent Pharma Inc. in the U.S. District Court for the District of New Jersey after Torrent filed an Abbreviated New Drug Application seeking approval for a generic version of Ravicti, an oral glycerol phenylbutyrate product used to treat chronic hyperammonemia associated with urea-cycle disorders. The case was an ANDA patent action under the Hatch-Waxman Act. The public docket reflects a negotiated resolution and dismissal rather than a trial or reported merits decision. The publicly available record does not disclose the settlement’s commercial terms or the earliest permitted Torrent launch date.

What drug and patents were involved in Horizon v. Torrent?

The litigation concerned Ravicti, whose active ingredient is glycerol phenylbutyrate. Horizon marketed Ravicti under FDA New Drug Application No. 203284. The product is an oral liquid administered to patients with urea-cycle disorders.

Horizon’s complaint followed Torrent’s Paragraph IV certification against patents listed for Ravicti in the FDA’s Approved Drug Products with Therapeutic Equivalence Evaluations, commonly called the Orange Book. A Paragraph IV certification alleges that a listed patent is invalid, unenforceable, or will not be infringed by the proposed generic product.

Product and regulatory profile

Item	Information
Reference drug	Ravicti
Active ingredient	Glycerol phenylbutyrate
Dosage form	Oral liquid
Reference sponsor	Horizon Medicines LLC and related Horizon entities
FDA application	NDA 203284
Regulatory pathway challenged	ANDA approval
Defendant	Torrent Pharma Inc.
Court	U.S. District Court for the District of New Jersey
Civil action	No. 2:21-cv-13396
Litigation type	Hatch-Waxman patent infringement action
Public resolution	Stipulated dismissal following negotiated resolution
Public trial or merits judgment	None reported

The Ravicti patent estate includes patents directed to glycerol phenylbutyrate compositions, pharmaceutical formulations, dosing, and treatment of urea-cycle disorders. The specific patents asserted against Torrent should be read together with the complaint and the Orange Book listings applicable when Torrent filed its ANDA. Patent listings and expiration dates can change through patent-term adjustments, corrections, delistings, or supplemental listings. The FDA Orange Book is the controlling source for listed patents and regulatory exclusivity information. (U.S. Food and Drug Administration, 2024a).

What was the procedural history of Horizon v. Torrent?

Horizon filed the action in 2021 after receiving notice of Torrent’s Paragraph IV certifications. The filing triggered the Hatch-Waxman statutory stay, which generally prevents FDA approval of the challenged ANDA for up to 30 months unless the court enters an earlier judgment or another statutory event terminates the stay.

The docket shows the standard sequence for an ANDA case:

1. Torrent filed an ANDA seeking approval of a generic Ravicti product.
2. Torrent provided Horizon with Paragraph IV notice.
3. Horizon filed an infringement action in the District of New Jersey.
4. The litigation proceeded under the Hatch-Waxman framework.
5. The parties resolved the dispute without a reported trial or claim-construction ruling.
6. The court entered a stipulated dismissal terminating the action.

The case therefore did not produce a precedential ruling on patent validity, claim scope, infringement, enablement, written description, obviousness, or inequitable conduct. The docket should not be treated as evidence that Torrent’s Paragraph IV defenses failed on the merits. It also does not establish that the asserted patents would have survived a validity challenge.

When does Torrent lose exclusivity for generic Ravicti?

The public litigation record does not disclose the settlement’s launch date or any license date granted to Torrent. That date is commercially important because a Hatch-Waxman settlement can permit a generic launch before the expiration of all Orange Book patents, subject to the negotiated license terms.

The relevant exclusivity layers are separate:

Exclusivity or protection	Effect
Orphan-drug exclusivity	Can block approval of the same drug for the same disease or condition for the statutory orphan period, subject to exceptions
New chemical entity exclusivity	Applies only if the FDA grants it and can prevent certain ANDA submissions during the exclusivity period
Patent protection	Can delay approval or launch through listed patents and related litigation
Pediatric exclusivity	Adds six months to qualifying regulatory protections
Settlement license	Can establish an agreed generic entry date that is earlier than patent expiration

Ravicti received orphan-drug regulatory protection because it treats a rare disease population. Orphan exclusivity and patent protection do not have identical expiration dates and do not create identical legal barriers. After regulatory exclusivity expires, a generic applicant may still face Orange Book patent litigation.

The stipulated dismissal in Horizon v. Torrent does not itself establish when Torrent may launch. A dismissal order without the settlement agreement does not disclose whether Torrent received a license, agreed to a delayed entry date, abandoned the ANDA, or retained the ability to continue development.

What patents protect Ravicti?

Ravicti’s patent protection is broader than a single composition patent. The estate has included claims directed to:

Glycerol phenylbutyrate compositions

These claims generally cover pharmaceutical compositions containing glycerol phenylbutyrate and related excipient or concentration limitations. Composition claims can create a direct infringement risk if a generic product uses the claimed active ingredient and formulation characteristics.

Oral liquid formulations

Ravicti is an oral liquid rather than a conventional tablet or capsule. Formulation patents can therefore be commercially important because they may cover excipient combinations, stability characteristics, concentration ranges, taste-masking approaches, or other product attributes needed for an acceptable liquid product.

A generic applicant may attempt to design around formulation claims by changing inactive ingredients, concentration, manufacturing conditions, or container configuration. The ability to design around depends on the exact claim language and whether the alternative product remains pharmaceutically equivalent under FDA requirements.

Methods of treating urea-cycle disorders

Method-of-use claims may cover administration of glycerol phenylbutyrate to patients with urea-cycle disorders, including dosage and treatment parameters. A generic applicant can attempt to carve out patented indications through a Section viii statement or labeling strategy. That approach is less effective where the protected use is difficult to omit from the proposed label or where the product’s approved use is closely tied to the claimed treatment method.

Dosing and administration

Some Ravicti claims may address dose conversion, administration frequency, patient populations, or treatment protocols. These claims can raise infringement issues even when a generic manufacturer uses the same active ingredient but proposes different labeling or dosing instructions.

How strong was Horizon’s patent estate against Torrent?

The estate was commercially meaningful but not necessarily impenetrable. Its strength depended on four variables: the number of unexpired claims, the breadth of the formulation claims, the ability to design around the liquid product, and the validity of method-of-use claims.

Strengths

• Ravicti is a specialized oral liquid with technical formulation requirements.
• Urea-cycle disorder treatment is a narrow therapeutic field with fewer direct substitutes.
• Formulation and manufacturing claims can make design-around strategies more difficult.
• The product’s orphan-disease indication may limit the commercial value of a generic carve-out.
• The 30-month stay creates negotiating leverage by delaying FDA approval while the case is pending.

Weaknesses

• Patent expiration is earlier than perpetual product protection.
• A generic applicant can challenge patents through Paragraph IV certifications.
• Method-of-use claims may be vulnerable to labeling carve-outs.
• Formulation claims can be narrowed or avoided through alternative excipient systems.
• The public docket contains no merits ruling confirming validity or infringement.

The resolution therefore indicates litigation risk management rather than a judicial determination of patent strength.

What was the Orange Book status of Ravicti?

Ravicti was listed in the Orange Book with patents covering aspects of the approved product. Orange Book listings provide the regulatory mechanism that connects an ANDA applicant’s Paragraph IV certification to patent litigation. They do not independently establish that each listed patent is valid or infringed.

The Orange Book should be reviewed for:

• Current patent numbers listed against NDA 203284.
• Patent expiration dates, including patent-term adjustments.
• Any pediatric exclusivity extension.
• Any later patent additions or delistings.
• The therapeutic-equivalence status of approved generic products.
• Whether an ANDA applicant has received approval, tentative approval, or final approval.

The Orange Book is a regulatory listing, not a substitute for the complaint, settlement agreement, or final judgment. (U.S. Food and Drug Administration, 2024a).

Did Torrent file a Paragraph IV challenge?

Yes. The litigation was brought after Torrent’s Paragraph IV certification concerning its proposed generic Ravicti product. The certification allowed Horizon to bring an infringement action before FDA approval of the ANDA.

A Paragraph IV notice can create several outcomes:

1. Patent litigation proceeds to trial.
2. The parties settle with a licensed future entry date.
3. The generic applicant abandons or modifies the ANDA.
4. The reference sponsor dismisses the case after resolving the dispute.
5. The court enters judgment on infringement or validity.

Horizon v. Torrent ended without a public merits judgment. The case therefore does not establish whether Torrent’s invalidity or noninfringement positions were legally persuasive.

Did the case produce a settlement agreement?

The public record indicates that the case was resolved and dismissed by stipulation. The material terms were not filed publicly or are not disclosed in the publicly available docket materials.

The absence of publicly available terms prevents a reliable determination of:

• Torrent’s licensed launch date.
• Whether Torrent received a royalty-bearing license.
• Whether the settlement included supply, manufacturing, or distribution restrictions.
• Whether the agreement contained an authorized generic arrangement.
• Whether the settlement included acceleration provisions.
• Whether the settlement covered affiliates or other Torrent entities.
• Whether the agreement resolved all Ravicti patent disputes.

The Federal Trade Commission and FDA settlement-reporting framework may provide regulatory reporting for qualifying brand-generic agreements, but public reporting does not always disclose the full economic terms or practical launch conditions. (Federal Trade Commission, 2023).

What litigation risk affected generic Ravicti entry?

Torrent faced several categories of risk.

Approval risk

FDA approval could have been delayed by the statutory stay and by any continuing Orange Book patent dispute. A court ruling against Torrent could have prevented approval until the relevant patent claims expired or were invalidated.

Labeling risk

A narrow carve-out could reduce infringement exposure but also limit the commercial value of the generic product. For a rare-disease medicine, removing a protected indication may materially reduce the addressable patient population.

Formulation risk

Ravicti’s liquid dosage form may require a formulation that closely tracks the reference product’s functional characteristics. A design-around could create pharmaceutical equivalence, stability, taste, dosing, or manufacturing problems.

Commercial risk

The urea-cycle disorder market is specialized. A generic entrant would face a smaller patient population than a conventional primary-care drug but could also encounter concentrated prescribing and reimbursement controls. Horizon’s established relationships with specialty providers and payers could affect the speed of generic conversion after launch.

How does Ravicti compare with conventional generic opportunities?

Factor	Ravicti	Conventional small-molecule tablet
Patient population	Rare-disease population	Often broader
Dosage form	Oral liquid	Frequently tablet or capsule
Formulation complexity	Relatively high	Often lower
Substitution dynamics	Specialty-driven	Pharmacy-driven in many markets
Method-of-use importance	High	Variable
Design-around potential	Depends on liquid formulation and label	Often greater for simple dosage forms
Manufacturing barriers	Specialized liquid production and controls	Commonly available solid-dose infrastructure
Generic launch economics	Potentially high price per patient, limited volume	Lower price, larger volume
Biosimilar risk	None in the conventional sense	None for ordinary small molecules

Ravicti is not a biologic, so biosimilar litigation is not the applicable competitive framework. The relevant threat is an ANDA generic, not a 351(k) biosimilar.

What manufacturing and intellectual-property barriers remain?

Manufacturing Ravicti-type products requires more than reproducing the active ingredient. A competing manufacturer must address:

• Glycerol phenylbutyrate sourcing and quality specifications.
• Impurity controls.
• Liquid formulation stability.
• Container-closure compatibility.
• Dose-measurement accuracy.
• Taste and patient acceptability.
• Scale-up and batch consistency.
• FDA pharmaceutical-equivalence requirements.
• Any process or formulation claims that remain enforceable.

These barriers can delay commercialization even after patent litigation ends. They also increase the probability that a generic entrant will launch cautiously, initially targeting selected specialty channels rather than immediately seeking broad substitution.

What is the commercial impact of the Horizon v. Torrent resolution?

The direct financial impact cannot be calculated from the public docket because the settlement terms and Torrent’s launch date are not disclosed. The commercial implications are still clear:

• Horizon preserved control over the timing and conditions of a potential Torrent entry.
• Torrent avoided the cost and uncertainty of a full patent trial.
• The settlement reduced immediate litigation expense for both parties.
• The market did not receive a judicial ruling invalidating the Ravicti patents.
• Any future generic entry remains dependent on the settlement terms, FDA approval, and the surviving Orange Book estate.

Horizon’s revenue exposure depends on the number of approved generic entrants, the timing of entry, the settlement’s license structure, payer substitution, and the availability of alternative treatments. A single authorized or licensed generic may have a materially different effect from an unrestricted, multi-manufacturer launch.

What is the current litigation status?

The Horizon v. Torrent action is closed on the public docket following a stipulated dismissal. There is no reported trial verdict, claim-construction decision, final written decision on patent validity, or publicly available injunction against Torrent.

The key unresolved commercial issue is the confidential settlement framework. The case disposition alone does not prove that Torrent abandoned its ANDA or that Horizon obtained a complete exclusion of Torrent from the market.

Key Takeaways

• Horizon Medicines LLC sued Torrent Pharma Inc. over a Paragraph IV ANDA challenge involving Ravicti, or glycerol phenylbutyrate.
• The case was filed in the District of New Jersey as Civil Action No. 2:21-cv-13396.
• The litigation involved Ravicti’s Orange Book patent estate, including formulation and method-of-use protection.
• The action ended through a stipulated dismissal rather than a public trial or merits judgment.
• The settlement terms, including any authorized launch date, are not publicly disclosed.
• Ravicti faces generic-entry risk through ANDA litigation, but not biosimilar competition.
• The product’s oral-liquid formulation, rare-disease indication, and specialty distribution model create additional commercial and manufacturing barriers.
• The public docket does not establish that the challenged patents were valid, infringed, or enforceable.

FAQs

Is Horizon v. Torrent a biologic or biosimilar case?

No. The case concerns a small-molecule drug, Ravicti, and arose under the ANDA pathway for generic drugs. Biosimilar rules under the Public Health Service Act do not apply.

Can Torrent launch a generic Ravicti product after the case was dismissed?

A dismissal does not establish launch permission. Torrent’s ability to launch depends on FDA approval, the terms of any confidential settlement or license, remaining patent rights, and regulatory exclusivity.

Did Horizon win the Ravicti patent case?

The public record does not show a merits victory. The parties resolved the action through dismissal, so there was no reported adjudication confirming infringement or patent validity.

Are Ravicti’s formulation patents more important than its method-of-use patents?

They can be. Because Ravicti is an oral liquid for a specialized indication, formulation claims may be difficult to avoid while maintaining an acceptable generic product. The relative importance depends on the precise claims and Torrent’s proposed formulation and labeling.

Does the Horizon-Torrent settlement establish the generic entry date for all Ravicti challengers?

No. A settlement with Torrent ordinarily binds the parties and covered affiliates identified in the agreement. It does not automatically determine the rights of other ANDA applicants or establish a universal market-entry date.

References

Federal Trade Commission. (2023). Agreements filed with the Federal Trade Commission and Department of Justice under the Medicare Prescription Drug, Improvement, and Modernization Act of 2003. https://www.ftc.gov

U.S. District Court for the District of New Jersey. (2021–2024). Horizon Medicines LLC v. Torrent Pharma Inc., No. 2:21-cv-13396. PACER/Court docket.

U.S. Food and Drug Administration. (2024a). Approved drug products with therapeutic equivalence evaluations: Orange Book. https://www.accessdata.fda.gov/scripts/cder/ob/

U.S. Food and Drug Administration. (2024b). Drugs@FDA: FDA-approved drugs, Ravicti, NDA 203284. https://www.accessdata.fda.gov/scripts/cder/daf/