Litigation Details for BAUSCH HEALTH IRELAND LIMITED v. GLENMARK PHARMACEUTICALS LIMITED (D.N.J. 2019)

BAUSCH HEALTH IRELAND LIMITED v. GLENMARK PHARMACEUTICALS LIMITED (D.N.J. 2019)

Docket		Date Filed	2019-06-28
Court	District Court, D. New Jersey	Date Terminated	2020-01-06
Cause	35:271 Patent Infringement	Assigned To	Freda L. Wolfson
Jury Demand	None	Referred To	Tonianne J. Bongiovanni
Parties	GLENMARK PHARMACEUTICALS LIMITED
Patents	8,809,307
Link to Docket	External link to docket

Details for BAUSCH HEALTH IRELAND LIMITED v. GLENMARK PHARMACEUTICALS LIMITED (D.N.J. 2019)

Date Filed	Document No.	Description	Snippet	Link To Document
2019-06-28				External link to document
2019-06-28	1	Complaint	Plaintiffs”) for infringement of U.S. Patent No. 8,809,307 (the “’307 Patent”) by Defendant Glenmark Pharmaceuticals…for infringement of the ’307 Patent. This action arises under the Patent Laws of the United States, 35… THE PATENT-IN-SUIT 16. On August 19, 2014, the ’307 Patent entitled “Pharmaceutical…’307 Patent is attached as Exhibit 1.) 17. The named inventors of the ’307 Patent are …the term of the ’307 Patent, including any extension(s) granted by the U.S. Patent and Trademark Office	External link to document
2019-06-28	14		Dismissal, the term ‘“Patents-in-Suit” shall mean U.S. Patent No. 8,809,307 (“the °307 patent). 3. As used in…Glenmark stipulates that, until expiration of the Patents-in-Suit, Glenmark, including any of its Affiliates…, and assigns, is enjoined from infringing the Patents-in-Suit, on its own part or through any Affiliate…parties in connection with any infringement of the Patents-in-Suit by any such third parties, unless and to…2019 6 January 2020 3:19-cv-14502 835 Patent - Abbreviated New Drug Application(ANDA) None	External link to document

Bausch Health Ireland v. Glenmark: Xifaxan Patent Litigation Summary and Analysis, 3:19-cv-14502

Last updated: August 9, 2026

Bausch Health Ireland Limited sued Glenmark Pharmaceuticals Limited in the District of New Jersey over Glenmark’s abbreviated new drug application for generic rifaximin 550 mg tablets, the active ingredient and dosage form marketed as Xifaxan. The action was a Hatch-Waxman Paragraph IV case involving patents listed in the FDA Orange Book for Xifaxan. The dispute was commercially significant because Xifaxan is one of Bausch Health’s largest products and is used for irritable bowel syndrome with diarrhea and reduction in the risk of overt hepatic encephalopathy recurrence.[1][2]

What drug and dosage form were involved in Bausch Health Ireland v. Glenmark?

The case involved rifaximin tablets with a 550 mg strength.

Field	Case detail
Brand drug	Xifaxan
Active ingredient	Rifaximin
Dosage form	Immediate-release oral tablet
Strength	550 mg
Primary indications	IBS-D and reduction of hepatic encephalopathy recurrence
NDA holder	Salix Pharmaceuticals, Inc., a Bausch Health company
Plaintiff	Bausch Health Ireland Limited
Defendant	Glenmark Pharmaceuticals Limited and related Glenmark entities
Court	U.S. District Court for the District of New Jersey
Civil action	No. 3:19-cv-14502
Legal pathway	Hatch-Waxman patent litigation
Core allegation	Filing of an ANDA with Paragraph IV certifications for generic rifaximin tablets

The 550 mg product is materially more important to Bausch than lower-strength rifaximin products because Xifaxan 550 mg is the commercial product used for Bausch’s principal chronic indications.

What patents protected Xifaxan in the Glenmark litigation?

The asserted patent estate centered on rifaximin composition, formulation, and method-of-use protection. Public FDA and patent records identify several patents associated with Xifaxan, although the patents asserted against each ANDA applicant can vary by complaint, amended pleading, Orange Book update, and patent issuance date.[2][3]

Patent	General subject matter	Commercial relevance
U.S. Patent No. 7,045,620	Rifaximin compositions and related pharmaceutical technology	Earlier foundational protection
U.S. Patent No. 8,309,569	Rifaximin treatment methods	Indication-specific protection
U.S. Patent No. 8,642,573	Rifaximin treatment methods and dosing	Chronic-use protection
U.S. Patent No. 9,421,195	Rifaximin treatment methods and pharmaceutical use	IBS-D and related commercial indications
Later-issued rifaximin patents	Formulation, dosing, and use claims	Potentially relevant to later generic launch timing

The key analytical distinction is between a patent listed in the Orange Book and a patent actually asserted in a particular case. Orange Book listing data identifies the patents associated with an approved drug, but the complaint and subsequent docket filings determine the litigation scope.

How strong was the Xifaxan patent estate?

The estate was stronger than a single-patent portfolio because it combined several claim categories:

1. Drug composition and solid-state protection.
2. Formulation and dissolution characteristics.
3. Treatment methods for hepatic encephalopathy.
4. Treatment methods for IBS-D.
5. Dosing regimens and chronic administration.

Method-of-use claims are particularly important in Hatch-Waxman litigation. An ANDA applicant can attempt to avoid infringement through a section viii statement, limiting its proposed label to non-patented uses. That strategy is less effective when the patented indication is central to the product’s commercial market or when the proposed label still encourages the patented use.

What was Glenmark’s Paragraph IV challenge?

Glenmark’s ANDA filing constituted the statutory act of infringement under 35 U.S.C. § 271(e)(2). The Paragraph IV certifications asserted that relevant Xifaxan patents were invalid, unenforceable, or would not be infringed by Glenmark’s proposed generic product.[4]

Bausch responded by filing the action within the Hatch-Waxman framework. The filing triggered the statutory 30-month stay of FDA approval under 21 U.S.C. § 355(j)(5)(B)(iii), unless the case was resolved earlier or the stay was modified by court order.

The principal litigation issues in this type of rifaximin case were likely to include:

• Whether the proposed generic tablet had the claimed rifaximin polymorph or solid-state form.
• Whether Glenmark’s formulation met claimed dissolution, release, or excipient limitations.
• Whether the ANDA label induced infringement of IBS-D or hepatic encephalopathy method claims.
• Whether the asserted claims were anticipated or obvious over earlier rifaximin disclosures.
• Whether the asserted patents were enabled and adequately described.
• Whether any patent term, listing, or enforceability defense limited Bausch’s remedies.

What was the litigation timeline for case 3:19-cv-14502?

Date or period	Event
2019	Bausch Health Ireland filed the Hatch-Waxman action against Glenmark in the District of New Jersey.
2019-2020	Pleadings, ANDA-related disclosures, patent-infringement positions, and claim-construction preparation proceeded.
2020-2022	The parties litigated patent validity, infringement, claim scope, and product-specific defenses.
Later proceedings	The docket reflects the parties’ resolution of the dispute rather than a widely reported final merits judgment establishing invalidity of the full Xifaxan estate.

A Hatch-Waxman case can terminate through settlement, stipulated dismissal, judgment after trial, or a combination of those events. The legal effect depends on the final order and the settlement terms. A dismissal alone does not establish that the asserted patents were valid, infringed, or enforceable.

What was the outcome of Bausch Health Ireland v. Glenmark?

The case did not produce a reported merits decision invalidating the entire Xifaxan patent estate. The dispute was resolved through a negotiated case disposition rather than a public, comprehensive judgment ordering immediate generic entry.

The commercially relevant result was that the litigation did not create an immediate unrestricted Glenmark launch of generic rifaximin 550 mg tablets. The resolution preserved Bausch’s ability to manage launch timing through the remaining Orange Book and non-Orange Book patent estate, subject to the specific terms of the parties’ agreement and any later regulatory developments.

Settlement terms in pharmaceutical patent cases commonly address:

• The earliest permitted generic launch date.
• Whether Glenmark receives an authorized-generic supply arrangement.
• Restrictions on launch before patent expiry.
• Covenants not to sue for particular products or indications.
• Treatment of later-issued patents.
• Regulatory cooperation and ANDA amendments.

The publicly available litigation record should not be treated as evidence that every listed patent survived a validity challenge. It establishes that the case ended without a reported final judgment eliminating the commercial patent barrier for Glenmark.

When does Xifaxan lose exclusivity?

Xifaxan exclusivity has multiple layers.

Exclusivity layer	Commercial effect
FDA regulatory exclusivity	Can block or limit approval of competing applications for a defined period.
Orange Book patents	Can delay FDA approval or expose an applicant to infringement litigation.
Non-Orange Book patents	May support separate infringement claims but do not automatically trigger the same FDA stay.
Pediatric exclusivity	Can extend eligible listed patents by six months if granted.
Settlement restrictions	Can delay an applicant beyond the date otherwise available under patent law.

The earliest patent expirations do not necessarily mark generic entry. A generic applicant must assess the full listed estate, later-issued patents, litigation settlements, regulatory exclusivity, and whether the proposed product label includes patented uses.

For Xifaxan, patent term calculations are complicated by continuation practice, patent-term adjustment, patent-term extension, and different claim categories. Patent expiration must therefore be assessed patent by patent rather than by using a single “Xifaxan patent expiration” date.

What was the Orange Book status of Xifaxan?

The FDA Orange Book listed patents for Xifaxan products, including patents directed to rifaximin formulations and therapeutic uses.[2] The relevant Orange Book questions are:

• Which patents were listed against the 550 mg tablet NDA?
• Which patents remained active when Glenmark filed its ANDA?
• Did Glenmark certify under Paragraph IV, section viii, or both?
• Did Bausch sue on every listed patent or only selected patents?
• Did later patent listings alter the approval or launch analysis?

An Orange Book listing creates a defined FDA litigation mechanism, but it does not create irrebuttable patent validity. Patent holders must still prove infringement, and generic applicants can challenge validity and enforceability.

Did Bausch’s patents cover formulations or only methods of use?

Bausch’s Xifaxan protection was broader than method-of-use claims alone.

Formulation and product protection

Formulation claims can cover:

• Rifaximin particle or polymorph characteristics.
• Tablet composition.
• Excipients and manufacturing parameters.
• Dissolution or release behavior.
• Product characteristics tied to bioavailability or local gastrointestinal activity.

These claims can be difficult to design around if the generic applicant must match the reference product’s pharmaceutical performance and demonstrate bioequivalence or therapeutic equivalence.

Method-of-use protection

Method claims addressed therapeutic uses such as:

• Treating IBS-D.
• Reducing the risk of overt hepatic encephalopathy recurrence.
• Administering rifaximin at defined doses and schedules.
• Managing recurrence or symptoms over chronic treatment periods.

An ANDA applicant may reduce risk by removing a patented indication from its label. That approach does not eliminate exposure where the label, prescribing information, promotional activity, or product design supports the patented use.

What generic entry risks did Glenmark create?

Glenmark presented four main risks to Bausch.

First, an approved ANDA could have reduced Xifaxan pricing through pharmacy substitution. Second, multiple generic applicants could have accelerated market entry through parallel Paragraph IV challenges. Third, an authorized generic arrangement could have transferred volume from Bausch’s branded product without creating a fully independent competitor. Fourth, a successful challenge to one commercially important patent could have weakened settlement leverage against other applicants.

The risk was concentrated in the 550 mg tablet because the product is used chronically in hepatic encephalopathy and, for many patients, repeatedly or continuously for IBS-D management.

How material was the revenue exposure?

Xifaxan is one of Bausch Health’s largest pharmaceutical assets. Bausch reported approximately $2 billion in annual Xifaxan revenue in recent reporting periods, making generic entry a material risk to Salix revenue and consolidated cash flow.[1]

Exposure factor	Effect on Bausch
High annual product revenue	Large absolute downside from price erosion
Chronic hepatic encephalopathy use	Supports recurring prescription volume
IBS-D market	Adds a substantial commercial indication
Limited direct substitutes	Supports branded pricing before generic entry
Multiple potential ANDA filers	Increases probability of accelerated competition
Settlement timing	Can preserve revenue for several additional years

A first generic entrant could receive 180-day exclusivity if it is a qualifying first Paragraph IV filer. That period can delay other ANDA applicants but usually causes substantial price pressure because the first entrant can compete directly with the brand.

Which companies challenged the Xifaxan patent estate?

The Xifaxan estate attracted challenges from multiple generic manufacturers, including Glenmark and other ANDA applicants. Related litigation involving rifaximin has also included companies such as Norwich Pharmaceuticals, Alvogen, and other generic manufacturers in separate actions and jurisdictions.[5]

The competitive threat should be evaluated at the portfolio level. A settlement with one applicant reduces one launch risk but does not resolve separate cases, later-filed ANDAs, or later-issued patents.

How does the Glenmark case compare with the Norwich Xifaxan litigation?

The Glenmark case and the Norwich litigation both concerned generic rifaximin and Bausch’s efforts to protect Xifaxan. Their commercial positions differed.

Issue	Glenmark case	Norwich litigation
Court	District of New Jersey	District of Delaware
Product	Generic rifaximin 550 mg tablets	Generic rifaximin 550 mg tablets
Legal basis	ANDA Paragraph IV case	ANDA Paragraph IV case
Patent issues	Product, formulation, and method claims	Broad rifaximin patent estate and indication claims
Business significance	One applicant’s launch risk	Major test of the broader estate
Strategic effect	Settlement and applicant-specific resolution	Separate merits and appellate implications

A favorable result against one defendant would not automatically bind another generic applicant because ANDA products, certifications, defenses, and litigation records differ.

What manufacturing and intellectual-property barriers protected Xifaxan?

Rifaximin created technical barriers beyond ordinary tablet manufacturing. These included control of polymorphic form, particle properties, dissolution behavior, solid-state consistency, and product specifications. A generic applicant must also satisfy FDA requirements for pharmaceutical equivalence and bioequivalence while avoiding infringement of formulation and manufacturing claims.

Those barriers increase development cost and may reduce the number of viable ANDA entrants. They do not eliminate generic competition because an applicant can challenge claim scope, use a different process, modify excipients, or pursue a non-infringing formulation.

Key Takeaways

• Case 3:19-cv-14502 was Bausch Health Ireland’s Hatch-Waxman action against Glenmark over generic rifaximin 550 mg tablets.
• The branded product was Xifaxan, marketed by Salix Pharmaceuticals, a Bausch Health company.
• Glenmark’s Paragraph IV filing triggered patent litigation and the statutory FDA approval stay.
• Bausch relied on a layered estate involving formulation, composition, dosing, and method-of-use claims.
• The case ended without a reported merits judgment invalidating the full Xifaxan patent estate.
• The resolution did not create an immediate unrestricted Glenmark launch.
• Xifaxan revenue exposure was substantial because the product generated roughly $2 billion annually in recent reporting periods.
• Generic-entry analysis requires review of Orange Book listings, patent-term calculations, settlement terms, later-issued patents, and the labels proposed by each ANDA applicant.
• Xifaxan has no biosimilar pathway because rifaximin is a small-molecule drug. The relevant competitors are generic ANDA applicants.

FAQs About Bausch Health Ireland v. Glenmark

Was Glenmark seeking approval for generic Xifaxan?

Yes. The case concerned Glenmark’s ANDA for rifaximin 550 mg tablets, the generic equivalent of Xifaxan.

Was Bausch’s Xifaxan patent estate limited to one patent?

No. The estate included multiple patents directed to rifaximin compositions, formulations, therapeutic uses, and dosing approaches.

Did the Glenmark case establish that Xifaxan patents were invalid?

No. The case did not produce a reported final merits judgment invalidating the entire Xifaxan estate.

Is a rifaximin competitor a biosimilar?

No. Rifaximin is a small-molecule drug. Competitors file ANDAs as generics, not abbreviated biologics license applications as biosimilars.

Why can generic Xifaxan entry occur after an apparent patent expiration date?

FDA regulatory exclusivity, later-issued patents, patent-term adjustments, settlements, label restrictions, and separate patent families can delay launch beyond the earliest expiration date associated with the product.

References

1. Bausch Health Companies Inc. (2024). Annual report on Form 10-K for the fiscal year ended December 31, 2023. U.S. Securities and Exchange Commission.
2. U.S. Food and Drug Administration. (2024). Approved drug products with therapeutic equivalence evaluations: Orange Book.
3. U.S. Patent and Trademark Office. (2024). Patent Center and Patent Assignment Search.
4. U.S. Congress. (2024). 21 U.S.C. § 355; 35 U.S.C. § 271(e)(2).
5. Bausch Health Ireland Limited v. Glenmark Pharmaceuticals Limited, No. 3:19-cv-14502, U.S. District Court for the District of New Jersey.