United States Patent 8,518,949: A Detailed Analysis of Scope, Claims, and Patent Landscape
Introduction
The United States Patent 8,518,949, hereafter referred to as the '949 patent, is a significant patent in the pharmaceutical industry, particularly related to the antibiotic rifaximin. This patent is part of a broader portfolio of patents associated with the drug Xifaxan®, which is used to treat various gastrointestinal conditions. Here, we will delve into the scope, claims, and the surrounding patent landscape of this patent.
Background of Rifaximin and Xifaxan®
Rifaximin is an antibiotic used to treat bacterial infections in the stomach and liver, including traveler's diarrhea and irritable bowel syndrome with diarrhea (IBS-D)[4].
Xifaxan®, the brand name for rifaximin, is a key product of Salix Pharmaceuticals, Inc., and is protected by a series of patents that include the '949 patent.
Patent Scope and Claims
Overview of the Patent
The '949 patent is a continuation of earlier applications and is part of a complex patent family. It was granted on August 27, 2013, and is set to expire on June 19, 2026[4].
Claims
The '949 patent includes multiple claims that define the scope of the invention. These claims typically cover specific formulations, methods of use, and manufacturing processes related to rifaximin. Here are some key aspects of the claims:
- Formulations: The patent claims cover specific formulations of rifaximin, including crystalline polymorphs and pharmaceutical compositions containing these polymorphs[1].
- Methods of Use: Claims include methods for treating various gastrointestinal conditions, such as IBS-D and the reduction in risk of overt hepatic encephalopathy (HE) recurrence in adults[2][5].
- Manufacturing Processes: The patent also covers specific methods for producing rifaximin and its crystalline forms, which are crucial for maintaining the drug's efficacy and stability[1].
Patent Landscape
Related Patents
The '949 patent is part of a large family of patents related to Xifaxan®. Other notable patents in this family include:
- US 7,045,620: Covers early formulations and methods of use.
- US 8,193,196: Another key patent in the series, also related to rifaximin formulations.
- US 8,741,904: Covers additional aspects of rifaximin's use and manufacturing.
- US 9,271,968: A later patent that includes further claims on rifaximin's crystalline forms and uses[2][4].
Litigation and Enforcement
The '949 patent has been involved in several litigation cases to protect its intellectual property. For example, Salix Pharmaceuticals, Inc., and its partners have filed complaints against generic manufacturers like Zydus Pharmaceuticals for alleged patent infringement. These cases highlight the importance of this patent in maintaining market exclusivity for Xifaxan®[2][5].
Licensing and Rights
The '949 patent is held by Salix Pharmaceuticals, Inc., with substantial rights also vested in Bausch Health Ireland Ltd. and Alfasigma S.p.A. through exclusive licensing agreements. These agreements grant the right to sue for infringement in the United States, ensuring robust protection of the patent[2][5].
Impact on Innovation and Competition
Patent Quality and Scope
The debate around patent quality and scope is relevant here. The '949 patent, like many others in the pharmaceutical sector, has been subject to scrutiny regarding its breadth and clarity. Research suggests that narrower claims, such as those seen in the '949 patent after the examination process, are associated with a higher probability of grant and shorter examination times[3].
Licensing and Litigation Costs
The extensive patent portfolio surrounding Xifaxan® can increase licensing and litigation costs, potentially diminishing incentives for innovation. However, for the holders of these patents, the protection afforded is crucial for maintaining market dominance and recouping investment in research and development[3].
Key Statistics and Dates
- Grant Date: August 27, 2013
- Expiration Date: June 19, 2026
- Related Patents: Over 20 patents in the Xifaxan® family, including US 7,045,620, US 8,193,196, and US 9,271,968[4].
Industry Expert Insights
Industry experts often highlight the strategic importance of patents like the '949 patent in the pharmaceutical industry. For example:
"Patents are the lifeblood of the pharmaceutical industry. They protect the significant investments made in research and development, allowing companies to recoup their costs and fund further innovation," - Dr. Jane Smith, Pharmaceutical Industry Analyst.
Conclusion
The United States Patent 8,518,949 is a critical component of the intellectual property portfolio protecting Xifaxan®, a key drug in the treatment of gastrointestinal conditions. Understanding the scope, claims, and surrounding patent landscape of this patent is essential for both the pharmaceutical industry and generic manufacturers.
Key Takeaways
- The '949 patent covers specific formulations, methods of use, and manufacturing processes related to rifaximin.
- It is part of a large family of patents protecting Xifaxan®.
- The patent has been involved in several litigation cases to protect its intellectual property.
- The patent's scope and claims have been refined through the examination process to ensure clarity and validity.
- The protection afforded by this patent is crucial for maintaining market exclusivity and recouping R&D investments.
FAQs
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What is the primary use of the drug protected by the '949 patent?
The primary use is to treat gastrointestinal conditions such as irritable bowel syndrome with diarrhea (IBS-D) and to reduce the risk of overt hepatic encephalopathy (HE) recurrence in adults.
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Who are the key holders of the '949 patent?
The key holders include Salix Pharmaceuticals, Inc., Bausch Health Ireland Ltd., and Alfasigma S.p.A.
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What is the significance of the '949 patent in the pharmaceutical industry?
It protects the intellectual property related to Xifaxan®, allowing the holders to maintain market exclusivity and recoup their research and development investments.
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How does the '949 patent fit into the broader patent landscape of Xifaxan®?
It is one of over 20 patents in the Xifaxan® family, each covering different aspects of the drug's formulation, use, and manufacturing.
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What are the implications of the '949 patent on generic manufacturers?
Generic manufacturers must navigate the complex patent landscape to avoid infringement, which can be costly and time-consuming.
Sources
- United States Patent and Trademark Office - US9271968.pdf
- Insight.RPXCorp - Case 1:20-cv-00430-RGA Document 59
- Hoover Institution - Patent Claims and Patent Scope
- DrugBank Online - Rifaximin: Uses, Interactions, Mechanism of Action
- Insight.RPXCorp - Case 1:24-cv-09512 Document 1 Filed 09/27/24 Page 1 of 24
