Details for Patent: 8,741,904

Which drugs does patent 8,741,904 protect, and when does it expire?

Patent 8,741,904 protects XIFAXAN and is included in one NDA.

This patent has thirty-four patent family members in twenty-six countries.

Summary for Patent: 8,741,904

Title:	Polymorphous forms of rifaximin, processes for their production and use thereof in the medicinal preparations
Abstract:	Crystalline polymorphous forms of the rifaximin (INN) antibiotic named rifaximin .delta. and rifaximin .epsilon. useful in the production of medicinal preparations containing rifaximin for oral and topical use and obtained by means of a crystallization process carried out by hot-dissolving the raw rifaximin in ethyl alcohol and by causing the crystallization of the product by addition of water at a determinate temperature and for a determinate period of time, followed by a drying carried out under controlled conditions until reaching a settled water content in the end product, are the object of the invention.
Inventor(s):	Viscomi; Giuseppe Claudio (Sasso Marconi, IT), Campana; Manuela (Bologna, IT), Confortini; Donatella (Calderara di Reno, IT), Barbanti; Maria (Bologna, IT), Braga; Dario (Bologna, IT)
Assignee:	Alfa Wassermann S.p.A. (IT)
Application Number:	13/950,642
Patent Litigation and PTAB cases:	See patent lawsuits and PTAB cases for patent 8,741,904
Patent Claim Types: see list of patent claims	Use; Composition; Delivery; Dosage form;

Detailed Analysis of the Scope and Claims of United States Patent 8,741,904

Introduction

United States Patent 8,741,904, hereafter referred to as the '904 patent, is a crucial component of the patent landscape surrounding Xifaxan®, a drug indicated for the reduction in risk of overt hepatic encephalopathy (HE) recurrence and the treatment of irritable bowel syndrome with diarrhea (IBS-D) in adults. This analysis will delve into the scope, claims, and the broader patent landscape associated with this patent.

Background of Xifaxan®

Xifaxan®, the brand name for the antibiotic rifaximin, is developed and marketed by Salix Pharmaceuticals, Inc., now part of Bausch Health. The drug has multiple indications and is protected by a robust patent portfolio[2][5].

Patent Overview

The '904 patent is part of a series of patents related to rifaximin, specifically focusing on crystalline polymorphous forms of the drug. Here are some key aspects:

Patent Title and Classification

The patent is titled "Crystalline polymorphous forms of rifaximin" and is classified under various international and U.S. patent classifications, including A61K 31/437 and C07D 498/22[4].

Patent Claims

The '904 patent includes multiple claims that define the scope of the invention. These claims typically cover:

• Composition of Matter: Specific crystalline forms of rifaximin, which are crucial for the drug's efficacy and stability.
• Methods of Preparation: Processes for producing these crystalline forms.
• Methods of Use: Indications for treating various conditions, such as hepatic encephalopathy and IBS-D[4].

Claim Scope and Breadth

The scope of the claims in the '904 patent is significant, as it covers not only the specific crystalline forms of rifaximin but also their use in medicinal preparations. The claims are designed to be broad enough to encompass various applications while being narrow enough to avoid invalidation due to prior art or lack of novelty. Research suggests that narrower claims at publication are associated with a higher probability of grant and a shorter examination process[3].

Patent Landscape

Related Patents

The '904 patent is part of a larger family of patents related to Xifaxan®, including other patents such as the '196, '949, '968, and '763 patents. These patents collectively protect various aspects of the drug, including its composition, methods of preparation, and methods of use[2][5].

Litigation and Enforcement

The '904 patent has been involved in several patent infringement cases. For instance, Salix Pharmaceuticals, Inc., and its affiliates have sued generic manufacturers like Zydus Pharmaceuticals for alleged infringement of this and other related patents. These lawsuits highlight the importance of the '904 patent in maintaining the exclusivity of Xifaxan® in the market[2][5].

Licensing and Agreements

The '904 patent is subject to various licensing agreements between Bausch Health, Salix Pharmaceuticals, Inc., and Alfasigma. These agreements grant exclusive rights to Bausch Health and Salix Pharmaceuticals, Inc. to sue for infringement and distribute Xifaxan® in the United States[2][5].

Impact on the Pharmaceutical Industry

Innovation and Competition

The robust patent protection provided by the '904 patent and its related patents has significant implications for innovation and competition in the pharmaceutical industry. While these patents protect the intellectual property of the innovator, they also create barriers for generic manufacturers, potentially delaying the entry of generic versions of Xifaxan® into the market[3].

Economic Considerations

The economic impact of the '904 patent is substantial. By extending the exclusivity period for Xifaxan®, the patent helps maintain higher drug prices, which can be beneficial for the patent holders but may increase healthcare costs for patients and insurers.

Key Takeaways

• Patent Scope: The '904 patent covers specific crystalline forms of rifaximin, methods of preparation, and methods of use.
• Related Patents: It is part of a larger patent family protecting various aspects of Xifaxan®.
• Litigation: The patent has been involved in several infringement cases to protect its exclusivity.
• Licensing: Subject to exclusive licensing agreements that grant rights to Bausch Health and Salix Pharmaceuticals, Inc.
• Industry Impact: Affects innovation, competition, and drug pricing in the pharmaceutical industry.

FAQs

1. What is the primary focus of the '904 patent? The '904 patent primarily focuses on crystalline polymorphous forms of the antibiotic rifaximin.

2. What are the main claims of the '904 patent? The main claims cover the composition of matter, methods of preparation, and methods of use for the crystalline forms of rifaximin.

3. How does the '904 patent fit into the broader patent landscape for Xifaxan®? It is part of a larger family of patents protecting various aspects of Xifaxan®, including composition, preparation, and use.

4. What are the implications of the '904 patent for generic manufacturers? The patent creates barriers for generic manufacturers, potentially delaying the entry of generic versions of Xifaxan® into the market.

5. Who holds the rights to the '904 patent in the United States? Bausch Health and Salix Pharmaceuticals, Inc. hold substantial rights, including an exclusive license and the right to sue for infringement in the United States.

Sources

1. DrugPatentWatch - XIFAXAN Drug Patent Profile
2. Insight.RPXCorp - Case 1:20-cv-00430-RGA Document 59
3. SSRN - Patent Claims and Patent Scope
4. Google Patents - United States Patent 8,741,904
5. Insight.RPXCorp - Case 1:24-cv-09512 Document 1 Filed 09/27/24

Drugs Protected by US Patent 8,741,904

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Patented / Exclusive Use	Submissiondate
Salix Pharms	XIFAXAN	rifaximin	TABLET;ORAL	021361-001	May 25, 2004		RX	Yes	Yes	8,741,904			Y		THE TREATMENT OF PATIENTS WITH TRAVELERS' DIARRHEA (TD) OR THE REDUCTION IN RISK OF OVERT HEPATIC ENCEPHALOPATHY (HE) RECURRENCE
Salix Pharms	XIFAXAN	rifaximin	TABLET;ORAL	021361-002	Mar 24, 2010		RX	Yes	Yes	8,741,904			Y		THE TREATMENT OF PATIENTS WITH TRAVELERS' DIARRHEA (TD) OR THE REDUCTION IN RISK OF OVERT HEPATIC ENCEPHALOPATHY (HE) RECURRENCE
Salix Pharms	XIFAXAN	rifaximin	TABLET;ORAL	021361-002	Mar 24, 2010		RX	Yes	Yes	8,741,904			Y		TREATMENT OF IRRITABLE BOWEL SYNDROME WITH DIARRHEA (IBS-D) IN ADULTS.
Salix Pharms	XIFAXAN	rifaximin	TABLET;ORAL	021361-002	Mar 24, 2010		RX	Yes	Yes	8,741,904			Y		TREATMENT OF IRRITABLE BOWEL SYNDROME WITH DIARRHEA (IBS-D) IN ADULTS AND SYMPTOMS THEREOF.

Foreign Priority and PCT Information for Patent: 8,741,904

Foriegn Application Priority Data
Foreign Country	Foreign Patent Number	Foreign Patent Date
	05004695	Mar 3, 2005

International Family Members for US Patent 8,741,904

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Australia	2006222312
Brazil	PI0608073
Canada	2594789
China	1900077