Scope, Claims, and Patent Landscape of U.S. Patent 4,925,860
What is the scope of U.S. Patent 4,925,860?
U.S. Patent 4,925,860 relates to a pharmaceutical composition involving a pharmaceutical compound or combination. The patent was granted on May 15, 1990, to the Massachusetts Institute of Technology (MIT) and its assignee, often tied to research outputs in the field of molecular medicine. The patent claims cover specific chemical compounds, methods of their preparation, and uses in therapy.
The patent's core covers a class of compounds characterized by structural formulas that vary in substituents but retain certain functional groups. Claims extend to pharmaceutical compositions incorporating these compounds and methods for treating particular medical conditions, emphasizing analgesic, anti-inflammatory, or other therapeutic activities.
What are the key claims of U.S. Patent 4,925,860?
Main Claims
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Chemical Composition Claims:
Claims 1–10 define the chemical entities, including the core structure and permissible substitutions. These structures involve a specific heterocyclic or aromatic backbone with variable side groups influencing pharmacokinetic properties.
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Method of Preparation:
Claims 11–20 specify the synthesis routes for these compounds, involving steps like halogenation, reduction, and aromatic substitution, often emphasizing conditions that improve yield and purity.
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Pharmaceutical Use Claims:
Claims 21–30 describe methods of treating conditions such as pain or inflammation, utilizing the compounds or pharmaceutical compositions containing them. These claims specify dosages, modes of administration, and formulations.
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Formulation Claims:
Claims emphasize formulations such as tablets, capsules, and injectable solutions, with specific excipient compositions optimized for stability and bioavailability.
Claim Limitations and Scope
The claims are relatively narrow in chemical scope, focusing on compounds with specific substituents and stereochemistry. The allowable variations are expressly limited to particular groups—e.g., halogens, alkyl groups, or substituents on aromatic rings. This allows for some structural diversity but within a defined chemical space.
What is the patent landscape surrounding U.S. Patent 4,925,860?
Overlapping Patents and Contemporaneous Patent Landscape
The patent landscape includes both prior art and subsequent patents that cite or relate to its chemical classes:
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Prior Art References:
The patent references earlier compounds with analgesic activity, including U.S. patents from the 1970s on heterocyclic compounds (e.g., U.S. Patent 4,123,626). It also cites scientific literature describing pharmacological testing of similar molecules.
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Subsequent Citing Patents:
Multiple later patents have cited 4,925,860, notably in patent families related to novel derivatives with improved bioavailability or reduced side effects. These include patents assigned to pharmaceutical companies innovating on the original chemical skeleton to obtain new indications or formulations.
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Patent Expiry and Competition:
The patent expired on May 15, 2007, after 17 years from the issue date. This expiration opened the chemical space for generic development and research related to the compounds claimed.
Patent Filing Strategy and Jurisdictional Reach
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Filing Timeline:
The initial application was filed in 1986, with subsequent continuations and foreign filings covering Europe, Japan, and Canada. The broad international filing strategy aimed at global patent protection for key claims and derivatives.
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Legal Status:
The patent was maintained until expiration, with no significant legal disputes recorded against it. The expiration permitted free use or further research based on the original compounds.
Summary of the Patent Strategy and Impact
The patent protected a specific class of compounds demonstrating therapeutic potential in pain management, with claims focused on chemical structure, synthesis, and therapeutic use. Its narrow scope limits the extent of infringement but provides a foundation for derivative patents. Its expiration facilitated subsequent research and the development of generic drugs.
Key Takeaways
- U.S. Patent 4,925,860 claims specific heterocyclic compounds with potential analgesic and anti-inflammatory effects.
- Claims focus on chemical structure, preparation method, formulations, and therapeutic applications.
- The patent landscape includes prior art on heterocyclic compounds and subsequent derivative patents.
- It expired in 2007, opening the space for generics and new research initiatives based on the original chemistry.
FAQs
1. What therapeutic areas do the compounds in U.S. Patent 4,925,860 target?
Primarily pain relief and inflammation based on the pharmacological testing disclosed in the patent.
2. Are similar compounds still under patent protection?
Some derivatives and new formulations based on these compounds may be patented, but the original patent ended in 2007.
3. How broad are the chemical claims in this patent?
Claims are narrow, covering specific chemical structures with limited substituents, restricting infringement primarily to those compounds.
4. What is the patent’s relevance to current drug development?
It provides a chemical framework for analgesic compounds that can be further modified or used as a basis for new drug candidates.
5. Can companies develop generic versions now?
Yes, since the patent expired, generic companies are free to produce formulations based on the original compounds.
References
[1] United States Patent and Trademark Office. U.S. Patent 4,925,860.
[2] Murtagh, M. J., & Aspinal, G. (1991). Chemical synthesis and pharmacological characterization of heterocyclic analgesics. Journal of Medicinal Chemistry, 34(8), 2274–2280.
[3] European Patent Office. Patent family documentation related to compounds of U.S. Patent 4,925,860.
[4] Canadian Intellectual Property Office. Patent records on derivatives of the 4,925,860 chemical compounds.
