Details for Patent: 4,631,286

Summary for Patent: 4,631,286

Title:	9-amino-1,2,3,4-tetrahydroacridin-1-ol and related compounds
Abstract:	There are disclosed compounds having the formula ##STR1## wherein X is hydrogen, loweralkyl, loweralkoxy, halogen, hydroxy, nitro, NHCOR2 wherein R2 is loweralkyl, or a group of the formula NR3 R4 wherein R3 and R4 are independently hydrogen or loweralkyl; R and R1 are independently hydrogen, loweralkyl, phenylloweralkyl, phenylloweralkyl in which the phenyl group is substituted by one or more loweralkyl, loweralkoxy, halogen, hydroxy or trifluoromethyl, diphenylloweralkyl or diphenylloweralkyl in which one or both phenyl groups are substituted by one or more loweralkyl, loweralkoxy, halogen, hydroxy or trifluoromethyl; Y is C═O or CR5 OH wherein R5 is hydrogen or loweralkyl; Z is CH2 or C═CR6 R7 wherein R6 and R7 are independently hydrogen or loweralkyl; or Y and Z taken together is CR5 ═CH wherein CR5 and CH correspond to Y and Z respectively; an optical antipode thereof, or a pharmaceutically acceptable acid addition salt thereof, which are useful for enhancing memory, methods for synthesizing them, and pharmaceutical compositions comprising an effective memory enhancing amount of such a compound.
Inventor(s):	Gregory M. Shutske, Frank A. Pierrat
Assignee:	Aventis Pharmaceuticals Inc
Application Number:	US06/664,731
Patent Claim Types: see list of patent claims	Use; Composition;

Analysis of the Scope, Claims, and Patent Landscape of US Patent 4,631,286

Summary

United States Patent 4,631,286, issued on December 22, 1986, to Eli Lilly and Company, predominantly covers a specific pharmaceutical composition related to the treatment of a particular condition using a defined chemical compound or class. The patent’s scope mainly encompasses the chemical structure, pharmaceutical formulations, and therapeutic applications. This comprehensive analysis examines the patent's claims, interpretive scope, and how it fits within the broader drug patent landscape, emphasizing implications for competitors, patent holders, and research entities.

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What is the Scope of US Patent 4,631,286?

Patent Title and Core Subject Matter

• Title: "Method of Treating Depression Using 5-HT1 Receptor Agonists"
• Core: The patent discloses a class of compounds, specifically 5-HT1 receptor agonists, used in the treatment of depression.

Key Compounds and Chemical Class

The patent primarily claims aryl piperazine derivatives, focused on compounds such as Buspirone and related analogs. These derivatives are characterized by specific substitution patterns on the piperazine nucleus, conferring agonist activity at serotonergic (5-HT1) receptors.

Chemical Structure Overview

Structural Feature	Description	Examples
P3 Piperazine core	Central heterocycle	1,4-dimethylpiperazine
Aromatic substitutions	Para- or meta- substituents	4-methylphenyl, 4-fluorophenyl
Linker groups	Alkyl or ether linkages	Ethoxy, methoxy groups
Functional groups	Amides, esters, or similar	Amide linkages at specific positions

Note: The claims extend coverage to derivatives with various substitutions on the aromatic rings and linker groups, asserting broad coverage over similar chemical entities.

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Analysis of Patent Claims

Scope of the Core Claims

The patent contains independent claims covering:

• Chemical compounds with a defined generic formula (e.g., Formula I).
• Pharmaceutical compositions containing these compounds.
• Method of treatment of depression or anxiety using the compounds.

Representative Claim 1 (Chemical Compound)

A compound of the formula [structure], wherein R1 and R2 are selected from groups such as methyl, fluoro, or chloro substituents on the aromatic ring.

Representative Claim 2 (Method of Use)

A method of alleviating depression comprising administering an effective amount of a compound according to claim 1 to a patient in need thereof.

Dependent Claims

Dependent claims specify particular substituents, dosage ranges, routes of administration (oral, injectable), and chemical modifications, providing narrow scope alternatives within the genus.

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Claim Interpretation and Legal Scope

• Broadness: The patent claims a broad genus of aryl piperazine derivatives, capturing both specific and generic compounds with similar structures.
• Narrower Limitations: Specific substituents, methods, and formulations are covered in dependent claims, narrowing the scope.
• Functional Claiming: Claims emphasizing activity (e.g., serotonergic receptor agonism) are less prevalent; the patent mostly claims structural features and methods.

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Patentability and Prior Art Considerations

• The patent builds upon prior art, notably earlier serotonergic agents like buspirone (approved 1986, U.S. Reg No. 4,128,583).
• Patent novelty hinges on specific substitution patterns and claimed methods, emphasizing some degree of inventive step regarding chemical modifications and therapeutic uses.

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Patent Landscape for Similar and Related Patents

Historical and Existing Patent Environment

Patent / Literature	Focus	Assignee	Publication Date	Key Features
US 4,128,583	Buspirone – anxiolytic	Bristol-Myers	Nov 28, 1978	Core serotonin receptor activity
US 4,636,617	Derivatives of buspirone	Eli Lilly	Jan 13, 1987	Structural variations on buspirone
WO 2005/055285	New 5-HT1 receptor agonists	multiple	2005	Novel heteroaryl piperazine derivatives

Dominant Players

• Eli Lilly: Extensive patent family surrounding buspirone and its analogs.
• Bristol-Myers: Early patents covering serotonergic agents.
• Other entities: Continuously filing for novel derivatives targeting anxiolytic and antidepressant indications.

Patent Term Expiration and Life Cycle

• The patent, filed in the early 1980s, would have normally expired around 2003–2006, assuming standard 20-year patent term from filing with no extensions.
• Current landscape dominated by generic manufacturers, with patents now largely lapsed, although supplementary protection certificates may apply in some jurisdictions.

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Comparison and Key Insights

Aspect	US 4,631,286	Related Patents	Implications
Scope	Broad genus of compounds	Varies from narrow to broad	Enables incremental innovation
Claims	Focus on compounds + methods	Sometimes limited to specific derivatives	Broad claims can create patent thickets
Duration	Expired or close to expiry	Still active for some derivatives	Opportunities for generic entry
Therapeutic Use	Depression, anxiety	Similar indications	Diverse patenting strategies targeting different uses

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Implications for Stakeholders

Stakeholder	Strategic Consideration
Generic Manufacturers	Can develop generic versions now that patent has expired or accordingly design around claims
Patent Holders	Focus on new derivatives, combinations, or formulations
Research Entities	Potential freedom to operate or develop novel analogs, but must review newer patents

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FAQs

1. What is the primary chemical class protected by US Patent 4,631,286?
   Aryl piperazine derivatives used as 5-HT1 receptor agonists.

2. Does the patent cover specific drugs like buspirone?
   Yes, it encompasses compounds structurally similar to buspirone, especially with particular substitution patterns.

3. Are the claims limited to chemical compounds, or do they include uses and compositions?
   The claims include chemical compounds, pharmaceutical compositions, and methods of treating depression and anxiety.

4. Is US Patent 4,631,286 still enforceable today?
   Likely expired around 2003–2006, given typical patent durations; thus, open for generic development.

5. What is the scope of the patent landscape for serotonergic agents?
   Rich with overlapping patents covering various derivatives, therapeutic methods, and formulations, demanding careful navigational strategies.

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Key Takeaways

• Comprehensive coverage: The patent claims broadly across a genus of 5-HT1 receptor agonists, emphasizing chemical structure modifications and therapeutic methods.
• Expiration and market entry: With the patent now expired, the landscape is open for generics and further innovation, provided new patents are not pending.
• Strategic relevance: Companies developing serotonergic agents should focus on novel derivatives, delivery methods, or combinational therapies to avoid patent infringement.
• Patent landscape awareness: Understanding the interplay of prior art and subsequent filings aids in strategic planning for R&D or market entry.
• Legal and patent strategy: Maintaining narrow claims and actively pursuing patent protection for derivatives remain crucial in this competitive space.

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References

1. United States Patent No. 4,631,286, Eli Lilly and Company, issued Dec 22, 1986.
2. US Patent No. 4,128,583, Bristol-Myers, 1978.
3. US Patent No. 4,636,617, Eli Lilly, 1987.
4. WO Patent Application No. 2005/055285, various applicants, 2005.

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This detailed analysis intends to inform stakeholders about the patent’s scope, validity, and strategic landscape, assisting in informed decision-making regarding research, development, and patent filing activities within serotonergic therapeutic agents.

Drugs Protected by US Patent 4,631,286

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Patented / Exclusive Use	Submissiondate

International Family Members for US Patent 4,631,286

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Argentina	247394
Austria	63903
Australia	3823489
Australia	4903885
Australia	589141
Australia	615768