Detailed Analysis of the Scope, Claims, and Patent Landscape for U.S. Patent 5,686,060
Overview of U.S. Patent 5,686,060
U.S. Patent 5,686,060, granted on November 4, 1997, to Yamanouchi Pharmaceutical Co., Ltd. (now part of Astellas Pharma), centers on a novel class of benzoquinone derivative compounds with potential therapeutic applications, primarily in cancer treatment and other disease modalities involving oxidative stress modulation.
The patent broadly claims methods of synthesizing these derivatives, pharmaceutical compositions containing them, and their use in disease treatment. This patent plays a pivotal role in the landscape of antioxidant and anticancer agents, particularly targeting reactive oxygen species (ROS) pathways.
Scope and Core Claims
Core Claims Analysis:
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Claim 1: The broadest claim, it defines a benzoquinone derivative characterized by specific chemical substitutions on the quinone ring, notably at particular positions, with a defined general formula (I).
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Claim 2-10: These specify particular substitutions, such as alkyl, alkoxy, amino groups, and other functional groups at designated positions, narrowing the scope but enhancing enforceability over specific analogs.
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Claim 11-15: These claims cover methods of synthesizing the claimed compounds, involving specific chemical reactions and intermediates.
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Claim 16-20: Focus on the pharmaceutical compositions comprising the compounds, including dosage form details.
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Claim 21-25: Assert methods of treatment using the compounds, particularly in cancer, ischemic diseases, and oxidative stress-related conditions.
Scope Analysis:
The claims are structured to protect a chemical class of compounds with specific substituents, emphasizing therapeutic utility. Claim 1’s broad scope covers any benzoquinone derivative with the specified structural motifs, establishing a strong foundational patent. The subsequent dependent claims refine the scope to particular embodiments, offering layered protection.
Chemical and Structural Landscape
The patent's core compounds resemble benzoquinone derivatives with potential antioxidant and anticancer properties. Factors influencing patent scope include:
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Genus claim: The broad chemical formula permits a wide array of analogs, provided they meet the structural criteria.
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Substituents: Variations at specified positions (e.g., R1-R4 groups) significantly expand the chemical space, increasing potential infringing compounds.
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Therapeutic claims: These leverage the chemistry by associating compounds with specific disease indications, which influences subsequent patenting strategies in the therapeutic landscape.
Patent Landscape Context
Pre-Existing Art & Related Patents:
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The patent cites prior art related to quinone derivatives and their antioxidant effects. However, the inventive step resides in novel substitutions and specific synthesis routes.
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Post-issuance (post-1997): The patent serves as a cornerstone in the field of quinone-based antioxidants, influencing subsequent patents that endeavor to improve efficacy, reduce toxicity, or optimize delivery.
Subsequent Patents & Citing Literature:
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Numerous subsequent patents cite 5,686,060 as prior art, often to claim improved derivatives, formulations, or novel therapeutic methods involving quinone structures.
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Notable classes include naphthoquinones, benzoquinones, and alkylated quinones, focusing on antioxidant therapy, cancer treatment, and neuroprotective agents.
Geographic and Jurisdictional Reach:
While primarily a U.S. patent, counterparts exist in other territories, including Europe (EP patents) and Japan, reflecting the international significance of this compound class within the pharmaceutical innovation landscape.
Implications for Drug Development
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The broad claims allow generic manufacturers to develop derivatives that fall within the structural scope, requiring careful design-around strategies.
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The specific claims on synthesis provide freedom-to-operate challenges for custom manufacturing of these compounds, especially for clinical development phases.
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The patent’s expiration in 2014 has opened opportunities for biosimilar and generic development.
Current Patent Status
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Expiration: The patent has expired, which, combined with its broad teaching, permits free use of the described compounds—though subsequent patents in the same class may still impose certain restrictions.
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Legal Status: The patent remains a critical reference point in the quinone-based therapeutic patent landscape.
Conclusion
U.S. Patent 5,686,060 delineates a broad chemical class of benzoquinone derivatives with therapeutic claims rooted in their antioxidant and anticancer activity. Its comprehensive claims covering the chemical compounds, synthesis methods, and therapeutic uses establish a robust patent estate, influencing subsequent innovation in quinone-based pharmaceuticals.
The patent's expiration has democratized research into these compounds, but its foundational role ensures it remains a key reference for both patent strategists and drug developers seeking to operate within or around this chemical space.
Key Takeaways
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The patent's broad claims encapsulate a wide class of benzoquinone derivatives, offering extensive protection to their synthesis and use.
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Its strategic layering of primary, dependent, and method claims provides both comprehensive coverage and avenues for design-around.
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The expiration of patent rights on these compounds facilitates generics and biosimilars, expanding access and innovation in antioxidant and anticancer therapeutics.
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Understanding the patent landscape around quinone derivatives is vital for navigating potential infringement risks and identifying licensing opportunities.
FAQs
1. What is the significance of U.S. Patent 5,686,060 in pharmaceutical innovation?
It established foundational claims on benzoquinone derivatives with therapeutic potential, shaping subsequent drug development and patenting strategies in oxidative stress-related therapies.
2. Are compounds covered under this patent still protected today?
No; the patent expired in 2014, enabling broader use of the covered compounds. However, newer patents may impose restrictions depending on specific derivatives or formulations.
3. How does this patent influence current research in antioxidant therapy?
It provides a comprehensive reference point for chemical structures and synthesis methods, guiding the development of new derivatives or alternative compounds.
4. Can generic manufacturers develop drugs based on the compounds described in this patent?
Yes, following the expiration, provided they do not infringe upon subsequent patents or specific claims related to formulations or methods of use.
5. What are the strategic considerations when designing new quinone derivatives post-expiration?
Focus on structural modifications that fall outside the scope of expired claims, enhancing efficacy or reducing toxicity, while respecting remaining patent rights in related areas.
Sources:
[1] U.S. Patent 5,686,060.
[2] Patent referencing and citation data retrieved from public patent databases, including USPTO and EPO records.
[3] Scientific literature related to quinone derivatives and their pharmaceutical applications.
