United States Patent 7,906,542: A Detailed Analysis of Scope and Claims
Introduction
The United States Patent 7,906,542, hereafter referred to as the '542 patent, is part of a broader portfolio of patents related to the drug Xifaxan® (rifaximin). This patent is significant due to its implications in the pharmaceutical industry, particularly in the treatment of certain gastrointestinal conditions. Here, we will delve into the scope, claims, and the patent landscape surrounding this patent.
Background of Xifaxan®
Xifaxan®, or rifaximin, is a rifamycin antibiotic used primarily for the treatment of irritable bowel syndrome with diarrhea (IBS-D) and the reduction in risk of overt hepatic encephalopathy (HE) recurrence in adults[2].
Patent Overview
The '542 patent is one of several patents held by Salix Pharmaceuticals, Inc., now part of Bausch Health Companies, Inc. This patent is specifically related to the pharmaceutical compositions and methods of use of rifaximin.
Scope of the Patent
The scope of the '542 patent is defined by its claims, which outline the specific inventions and innovations covered. Here are some key aspects:
Claims
The patent includes multiple claims that define the scope of protection. These claims typically cover:
- Composition Claims: These claims describe the specific formulations of rifaximin, including its polymorphic forms (e.g., α, β, and γ forms)[4].
- Method Claims: These claims outline the methods of using rifaximin for treating specific conditions, such as IBS-D and HE recurrence[2].
- Dosage Forms: The patent also covers various dosage forms, including the 550 mg tablet form of Xifaxan®[2].
Independent Claims
Independent claims are crucial as they stand alone and do not depend on other claims. For the '542 patent, these might include claims related to the unique polymorphic forms of rifaximin and their preparation processes[4].
Patent Landscape
The '542 patent is part of a larger patent portfolio related to Xifaxan®. Here are some key points about the patent landscape:
Related Patents
The Xifaxan® patents include a series of patents with different expiration dates, ensuring extended market exclusivity for the drug. Other patents in this series include US7,045,620, US7,612,199, and US7,902,206, among others[2].
Litigation and Enforcement
The '542 patent has been involved in litigation to protect its validity and enforceability. For instance, in a case filed in 2020, the defendant admitted that certain claims of the '542 patent were valid and enforceable[2].
Expiration Date
The '542 patent is set to expire, which will open up the market for generic versions of Xifaxan®. This expiration is part of a broader trend of drug patents expiring in 2024, impacting the pharmaceutical industry significantly[1].
Metrics for Measuring Patent Scope
To understand the scope of the '542 patent better, metrics such as independent claim length and independent claim count can be used. These metrics help in assessing the breadth and clarity of the patent claims.
Independent Claim Length
This metric measures the number of words used in the shortest independent claim. Shorter claims often indicate narrower and more specific inventions, which can be easier to enforce but may offer less broad protection[3].
Independent Claim Count
This metric counts the total number of independent claims in the patent. A higher number of independent claims can indicate a broader scope of protection but may also increase the complexity and potential for litigation[3].
Impact on Innovation and Competition
The expiration of the '542 patent and other related patents will have significant implications for innovation and competition in the pharmaceutical industry.
Generic Competition
The expiration of these patents will allow generic manufacturers to enter the market, potentially reducing the cost of the drug and increasing access to patients. This competition can drive innovation as companies seek to develop new or improved treatments[1].
Licensing and Litigation
The broad scope of the Xifaxan® patents has led to significant licensing and litigation activities. As these patents expire, the landscape for licensing and litigation will change, potentially reducing costs associated with these activities[3].
Conclusion
The United States Patent 7,906,542 is a critical component of the patent portfolio for Xifaxan®, a drug with significant market presence. Understanding the scope and claims of this patent, as well as its place within the broader patent landscape, is essential for pharmaceutical companies, generic manufacturers, and regulatory bodies.
Key Takeaways
- Patent Scope: The '542 patent covers specific formulations and methods of use for rifaximin, including its polymorphic forms.
- Claims: The patent includes composition, method, and dosage form claims that define its scope.
- Patent Landscape: The '542 patent is part of a larger portfolio of Xifaxan® patents, with various expiration dates.
- Metrics: Independent claim length and count can help measure the breadth and clarity of the patent claims.
- Impact: The expiration of this patent will open the market to generic competition, potentially reducing costs and driving innovation.
FAQs
Q: What is the primary use of the drug covered by the '542 patent?
A: The primary uses of Xifaxan® (rifaximin) include the treatment of irritable bowel syndrome with diarrhea (IBS-D) and the reduction in risk of overt hepatic encephalopathy (HE) recurrence in adults.
Q: What are the key claims of the '542 patent?
A: The key claims include composition claims for the polymorphic forms of rifaximin, method claims for treating specific conditions, and dosage form claims.
Q: When is the '542 patent set to expire?
A: The exact expiration date of the '542 patent is not specified in the provided sources, but it is part of a series of patents expiring around 2024.
Q: How does the expiration of the '542 patent impact the pharmaceutical industry?
A: The expiration will allow generic manufacturers to enter the market, potentially reducing drug costs and increasing patient access, while also driving innovation.
Q: What metrics can be used to measure the scope of the '542 patent?
A: Metrics such as independent claim length and independent claim count can be used to assess the breadth and clarity of the patent claims.
Sources
- GreyB, List - 54 Drug Patents Expiring in 2024, GreyB Blog.
- Insight.rpxcorp.com, Case 1:20-cv-00430-RGA Document 59 Filed 11/13/20 Page 1 of 52.
- Hoover Institution, Patent Claims and Patent Scope, Hoover Institution Working Paper Series.
- Google Patents, US7906542B2 - Pharmaceutical compositions comprising polymorphic forms α, β, and γ of rifaximin.
