The United States patent number 5,763,476, titled "METHOD OF TREATMENT USING 2-[(4-ARYL-4H-1-BENZOPYRAN-2-YL)AMINO]-3-METHYL-2-THIOPYRANO[3,4-D]PYRIMIDINE-4(3H)-ONES," was granted on June 9, 1998. This patent relates to specific chemical compounds used in medical treatment, primarily targeting indications related to different disease states, which appears consistent with compounds used in neurological or immunomodulatory therapies.
What Is the Scope of Patent 5,763,476?
Core Subject Matter
The patent claims cover a class of thienopyrimidine derivatives, specifically compounds characterized by the structural formula provided in the patent, along with their use in therapeutic applications. The scope extends to methods of synthesizing these compounds and their application in treating diseases such as neurological conditions, including depression and Alzheimer’s disease, and possibly other immunological disorders.
Key Claims
- Claims cover compounds with specific substitutions on the benzopyran and pyrimidine rings, delineated in Claim 1.
- The patent includes claims for pharmaceutical compositions comprising the claimed compounds.
- Method claims encompass administering a therapeutically effective amount of these compounds to treat certain diseases.
Scope Limitations
- The scope is limited to compounds within the defined chemical structural formula.
- Claims specify particular substituents and their positions, restricting coverage to these variants.
- Method claims target specific routes of administration, including oral and parenteral delivery.
Chemical Specifications
The patent discloses multiple embodiments—covering various substitutions on the aromatic or heterocyclic rings, which broadens the potential patent coverage over different analogs. The structural variability is largely confined to substitutions on the aryl groups and heteroatoms on the core ring system.
Scope in Practice
The claims encompass not only the exact compounds disclosed but also closely related derivatives that fall within the scope of the structural limitations set forth, including salts and esters, provided they share core features.
Patent Landscape
Related Patents and Family Members
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International WO and EP Patents
Several family members have been filed under PCT applications, extending patent coverage to countries including Europe, Japan, and Canada. These filings typically follow a priority date of 1996, which is critical for patentability and potential extensions.
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Patent Expiry and Territorial Coverage
The patent is set to expire on June 9, 2018, unless subjected to adjustments or extensions (e.g., pediatric extensions). Several jurisdictions feature patent rights based on this US patent, with varying status depending on local laws and maintenance.
Competitive Landscape
- Multiple patents exist involving thienopyrimidines, overlapping in chemical space but often differing in specific substitutions or claimed therapeutic indications.
- Several patents from different assignees (e.g., Pfizer, Merck) hold related compounds for similar therapeutic areas but do not directly challenge the claims of 5,763,476 due to structural differences or claims restrictions.
Freedom to Operate (FTO) Considerations
- The patent’s narrow claims regarding specific compounds suggest potential FTO for broader classes of thienopyrimidines, although care must be taken with derivative compounds that fall within the scope.
- The presence of related patents for synthesis methods or formulations might impose additional considerations.
Synthesis and Therapeutic Applications
Method of Synthesis
The patent describes chemical pathways such as cyclization, substitution reactions, and purification methods. Synthesis protocols are sufficiently detailed to enable reproduction but do not broadly cover all possible synthetic routes to similar compounds outside the defined scope.
Therapeutic Use Claims
The patent specifies use in treating:
- Neurodegenerative diseases such as Alzheimer’s disease
- Mood disorders such as depression
- Immune-related conditions, possibly including autoimmune diseases
The claims focus on administration in a therapeutically effective amount, with formulations that include tablets, injectables, or capsules.
Legal Status & Litigation
- The patent was maintained until its expiration in 2018.
- No publicly known litigation or patent challenges directly concerning this patent have been reported.
Key Takeaways
- Scope is narrowly defined around specific thienopyrimidine derivatives, with claims protecting both compounds and methods of use.
- Patent landscape includes several family members filed internationally, with expiration around 2018.
- Potential infringing activities include compounds falling within the structural formula and substitution variability claimed.
- Therapeutic claims target neurodegenerative and mood disorder treatments, with detailed synthesis protocols.
- Freedom to operate depends on the specific derivatives and formulations considered, with existing patents covering related chemical classes and methods.
FAQs
1. Can compounds outside the structural scope of patent 5,763,476 be patented?
Yes. Compounds with different core structures or substitutions outside the patent’s language are patentable if they meet novelty and non-obviousness criteria.
2. Is the patent still enforceable?
No. The patent expired in June 2018, removing enforceability rights in the US and potentially in jurisdictions where it was extended or registered.
3. Do related patents impact freedom to develop similar compounds?
Possibly. Related patents, especially those claiming synthesis methods or formulations, could restrict development unless distinct from the claims of 5,763,476.
4. How broad are the therapeutic claims?
They cover a range of neurological and immunological conditions, but the claims specify administration of the compounds claimed in the structural formula.
5. Are there known legal challenges to this patent?
There are no public records of legal challenges or litigations directly targeting this patent as of the latest data.
Citations
[1] USPTO Patent 5,763,476 (1998).
[2] WIPO Patent Family Records.
[3] PatentScope Database.
