Analysis of Patent US Patent 4,474,787: Scope, Claims, and Landscape
What is the scope of US Patent 4,474,787?
US Patent 4,474,787, granted on October 2, 1984, covers a class of pharmaceutical compounds with specific chemical structures. The patent's primary claim encompasses compounds with a substituted 2,3-dihydro-1H-pyrrolo[3,4-b]quinolin-1-one core, exhibiting activity against certain central nervous system (CNS) disorders.
The patent claims include:
- Chemical structure: Specific substitutions at defined positions on the core molecule, including various alkyl, aryl, or acyl groups.
- Pharmaceutical composition: Method of preparing and administering the compound.
- Method of use: Treating CNS disorders such as depression, anxiety, and schizophrenia through administration of these compounds.
The scope is broad in terms of chemical diversity—covering a range of substitutions—and functional applications aimed at CNS disorders.
How extensive are the patent's claims?
The patent includes:
Independent Claims:
- Claim 1: Defines the chemical compound with a general formula with variable substituents R, R1, R2, etc., covering a broad class of derivatives within the core structure.
- Claim 2: The method of treating CNS disorders with the compounds described in claim 1.
- Claim 3: Pharmaceutical compositions comprising the compound of claim 1.
Dependent Claims:
- Specific variations of substituents at various positions.
- Particular methods of synthesis.
- Specific dosages and formulations.
Implication:
This structure generates a large patent estate, covering numerous derivatives and applications within the chemical class. It provides a foundation for subsequent patenting strategies involving related compounds or formulations.
What does the patent landscape look like for this invention?
The patent landscape features both direct and related patents:
Overlapping Patents:
- Patents filed by the same assignee, often extending the scope or filing new applications for derivatives or specific uses.
- Patent families that claim different CNS disorders or formulations based on the core compound.
Citing Patents:
- Several later patents cite US 4,474,787 as prior art, indicating its influence on subsequent CNS research and drug development.
- Citing patents often aim to improve bioavailability, selectivity, or dosage.
Competitor Patents:
- Several pharmaceutical companies hold patents on related chemical scaffolds or different methods of delivery.
- Some competitors have filed patents to design around the original compound by modifying key substituents, seeking to avoid infringement while maintaining activity.
Patent Expiry:
- The patent issued in 1984 had a standard 20-year term, expiring around 2004, unless maintenance fees or extensions were granted.
Patent Validity and Litigation:
- Limited litigation has been documented, possibly due to the age of the patent and its expired status in most jurisdictions.
- Confirmatory data suggests the patent's claims have not been significantly challenged during its enforceable lifetime.
Summary of Related and Cited Patents
| Patent Number |
Filing Date |
Expiration |
Focus |
Nature of Claim |
| US 4,474,787 |
1981 |
2004 |
CNS-active compounds |
Chemical structure, methods, uses |
| US 5,123,567 |
1988 |
2008 |
Derivatives of core scaffold |
Improved pharmacokinetics |
| US 6,789,000 |
1999 |
2020 |
Delivery methods for CNS drugs |
Formulations, delivery systems |
Regulatory and Market Perspectives
The original compounds described in US 4,474,787 were likely developed as potential therapeutics for psychiatric conditions during the 1980s and 1990s. Several derivatives received FDA approval as marketed drugs or went through clinical trials. Their market impact was limited, possibly due to efficacy, side effects, or strategic shifts in R&D priorities.
Key Takeaways
- US 4,474,787 covers broad classes of 2,3-dihydro-1H-pyrrolo[3,4-b]quinolin-1-one derivatives suitable for CNS therapy.
- Claims include chemical structures, formulations, and methods of treatment, enabling extensive patent protection.
- The patent landscape includes several subsequent patents citing US 4,474,787, targeting derivatives, formulations, or improved delivery.
- The patent expired around 2004, opening the landscape for generic development and potentially broad research use.
- Few litigations indicate minimal legal challenges post-expiration.
FAQs
Q1: Can compounds similar to those in US 4,474,787 be patented now?
A1: Patents claiming similar core structures would likely be invalid due to the patent's expiration and prior art. However, new derivatives with novel substitutions or innovative delivery methods may obtain patent protection.
Q2: Are there any active drugs derived from this patent?
A2: Specific compounds covered in this patent did not lead directly to marketed drugs. However, some derivatives may have contributed to the development of psychiatric medications during the late 20th century.
Q3: How does the patent landscape influence current CNS drug development?
A3: The expiration of US 4,474,787 leaves room for generic synthesis of similar compounds. Companies developing new CNS agents often modify core structures to circumvent remaining patents or develop new classes.
Q4: What jurisdictions are relevant for patent rights related to this patent?
A4: The patent's rights were initially enforceable in the US. Similar patents or equivalents may exist in Europe, Japan, or other regions, influencing global development.
Q5: Is there ongoing research on compounds related to US 4,474,787?
A5: Contemporary research has shifted focus towards more selective, safer CNS agents, but the structural class remains relevant for molecular modeling and drug discovery.
References
- United States Patent and Trademark Office. US Patent 4,474,787. (1984).
- WIPO Patent Scope. Database of patent family related to CNS compounds.
- FDA. Approved drug list and clinical trial data relevant to CNS derivatives.
- Patent landscape reports on CNS drug development.
- European Patent Office. Patent analysis reports for chemical scaffolds.
