United States Patent 5,260,291: A Detailed Analysis of Scope, Claims, and Patent Landscape
Introduction
United States Patent 5,260,291, titled "Tetrazine derivatives," is a significant patent in the pharmaceutical sector, particularly in the field of cancer research and treatment. This patent, granted to a British pharmaceutical company, covers a range of tetrazine derivatives and their applications. Here, we will delve into the scope, claims, and the broader patent landscape surrounding this invention.
Background and Invention Overview
The patent, filed on August 23, 1982, and granted subsequently, relates to new [3H-imidazo-5,1-d]-1,2,3,5-tetrazin-4-one derivatives. These compounds are described for their potential use in pharmaceutical compositions, particularly in the treatment of cancer[4].
Scope of the Patent
The scope of the patent is defined by the claims, which outline the specific inventions and their variations that are protected.
Claim Structure
The patent claims are structured around the general formula of the tetrazine derivatives, which includes various substituents and modifications. Key aspects include:
- R1 Substituents: These can be hydrogen atoms, straight- or branched-chain alkyl, alkenyl, or alkynyl groups containing up to 6 carbon atoms. These groups can be unsubstituted or substituted by halogen atoms (such as chlorine or fluorine), alkoxy, alkylthio, alkylsulphinyl, and alkylsulphonyl groups[4].
- R2 Substituents: These include carbamoyl groups or monoalkylcarbamoyl, monoalkenylcarbamoyl groups. The carbamoyl group can carry additional alkyl or alkenyl groups[4].
Pharmaceutical Applications
The patent covers the use of these tetrazine derivatives in pharmaceutical compositions. The compounds are particularly noted for their potential in treating cancer, highlighting their therapeutic value[4].
Claims Analysis
The claims of the patent are crucial as they define the boundaries of the invention.
Independent Claims
Independent claims are those that stand alone and do not depend on other claims. For US Patent 5,260,291, these claims typically describe the general formula of the tetrazine derivatives and their specific substituents. For example, Claim 1 might describe the general structure of the [3H-imidazo-5,1-d]-1,2,3,5-tetrazin-4-one derivatives, while subsequent claims might detail specific variations of R1 and R2 substituents[4].
Dependent Claims
Dependent claims build upon the independent claims and provide further specificity. These claims might cover specific types of substituents, such as the preference for chlorine or fluorine as halogen substituents, or the use of methyl or 2-haloalkyl groups[4].
Patent Landscape
Understanding the patent landscape is essential for assessing the impact and relevance of US Patent 5,260,291.
Prior Art and Citations
The patent cites prior art related to tetrazine derivatives and their synthesis. The Common Citation Document (CCD) application, which consolidates prior art cited by multiple patent offices, would be useful in identifying relevant prior art and ensuring the novelty of the claimed inventions[1].
International Patent Family
The patent is part of an international patent family, with filings in multiple jurisdictions. The Global Dossier service provided by the USPTO allows users to view the file histories of related applications from participating IP Offices, which can help in understanding the global reach and status of the patent[1].
Litigation and Enforcement
Patents like US 5,260,291 can be subject to litigation, especially in the highly competitive pharmaceutical industry. Cases such as Cancer Research v. Barr Labs highlight the importance of patent enforcement and the potential for disputes over patent validity and infringement[5].
Patent Term and Expiration
The patent term for US 5,260,291 has expired, as indicated by its legal status. However, the impact of this patent on subsequent research and development in the field of tetrazine derivatives remains significant. Patent term restoration applications, such as those related to regulatory review periods, can sometimes extend the life of a patent, but this is not applicable in this case[2].
Impact on Innovation
The scope and claims of US Patent 5,260,291 have contributed to the development of cancer treatments. However, debates over patent quality and scope suggest that overly broad patents can sometimes hinder innovation by increasing licensing and litigation costs. Metrics such as independent claim length and count can help measure patent scope and its impact on innovation[3].
Conclusion
US Patent 5,260,291 is a pivotal patent in the field of pharmaceuticals, particularly in cancer research. The detailed analysis of its scope and claims highlights the complexity and specificity of the inventions covered. Understanding the patent landscape, including prior art, international filings, and litigation, is crucial for both innovators and practitioners in this field.
Key Takeaways
- Specific Claims: The patent covers specific tetrazine derivatives with detailed substituents.
- Pharmaceutical Applications: The compounds are primarily for cancer treatment.
- Patent Landscape: Part of an international patent family with significant prior art and potential for litigation.
- Impact on Innovation: Contributes to cancer research but may be subject to debates over patent quality.
- Expiration: The patent term has expired, but its impact remains.
FAQs
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What is the main subject of US Patent 5,260,291?
- The main subject is tetrazine derivatives, specifically [3H-imidazo-5,1-d]-1,2,3,5-tetrazin-4-one derivatives.
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What are the potential applications of the inventions covered by this patent?
- The primary application is in pharmaceutical compositions, particularly for cancer treatment.
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How can one search for similar patents or prior art?
- Using tools like the USPTO's Patent Public Search, Global Dossier, and the Common Citation Document (CCD) application.
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Is the patent still in force?
- No, the patent term has expired.
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What are some metrics used to measure patent scope?
- Metrics include independent claim length and independent claim count, which can indicate the breadth and clarity of the patent claims[3].
Sources
- USPTO - Search for patents
- Federal Register - Determination of Regulatory Review Period
- SSRN - Patent Claims and Patent Scope
- Google Patents - Tetrazine derivatives
- Justia - CANCER RESEARCH V BARR LABS
