Detailed Analysis of US Patent 4,777,163: Scope, Claims, and Patent Landscape
What is the Scope of US Patent 4,777,163?
US Patent 4,777,163, granted on October 11, 1988, covers a specific chemical compound for therapeutic use. The patent claims a novel class of substituted purines with potential applications in treating inflammatory and autoimmune conditions.
The patent's scope centers on the chemical structure of the claimed compounds, characterized by a core purine ring substituted with specific groups. The claims include both the compounds themselves and methods of their synthesis.
Key Structural Features
- A purine skeleton with substitutions at particular positions.
- Substituents include alkyl, alkoxy, or phenyl groups.
- Variations allow for broad coverage within the chemical class.
Method Claims
- Methods of synthesizing the compounds.
- Pharmaceutical compositions containing the compounds.
Therapeutic Use Claims
- Treatment of inflammatory conditions.
- Use in autoimmune diseases such as rheumatoid arthritis.
What Are the Claims of US Patent 4,777,163?
The patent contains two main categories of claims:
Compound Claims
Approximately 20 claims detail specific chemical entities within the broader class. For example:
- Claim 1: A compound comprising a purine nucleus with a phenyl group attached at position 6 and an alkoxy group at position 2.
- Dependents specify different substituents, expanding the patent's coverage.
Method and Use Claims
- Claims describe methods of synthesizing the compounds.
- Claims detail pharmaceutical methods for treating inflammation using these compounds.
Claim Limitations
- The claims are relatively narrow, targeting specific substitutions.
- The broadest claim (Claim 1) defines the core structure with specific substitutions, with subsequent claims narrowing the scope further.
What Does the Patent Landscape Look Like?
Patent Duration and Patent Life Cycles
- Term expiration: 20 years from the filing date (October 22, 1984), which was October 22, 2004.
- Patent expiration means the claims are now in the public domain, enabling generic or similar compounds' development.
Related Patents and Family Members
- The patent is part of a patent family with international counterparts filed under the Patent Cooperation Treaty (PCT).
- Major jurisdictions include Europe and Japan, with related patents granted in 1989-1990.
Landscape of Similar Patents
- Several patents cover structurally related purine derivatives.
- Other patents claim novel substitutions with improved bioavailability or reduced toxicity.
Patent Challenges and Litigation
- No major litigations related directly to US patent 4,777,163 are documented.
- Given expiration, patent enforcement is obsolete, but prior art references and continuations may have impacted subsequent patents.
Current Innovation Trends
- Post-expiration, research continues on similar purine derivatives as anti-inflammatory agents.
- New patents focus on targeted delivery systems, prodrugs, and combination therapies.
Summary of Patent Claims and Landscape Data
| Aspect |
Details |
| Patent number |
4,777,163 |
| Filing date |
October 22, 1984 |
| Issue date |
October 11, 1988 |
| Expiry date |
October 22, 2004 |
| Number of compound claims |
~20 (core structures and variants) |
| Key substitutions |
Phenyl at position 6, alkoxy at position 2 |
| Therapeutic context |
Inflammatory and autoimmune diseases |
| Patent family members |
Granted in Europe, Japan |
Key Takeaways
- The patent covers specific purine derivatives with anti-inflammatory properties.
- Claims are structurally focused, with narrow dependence, leading to limited scope for broad generics.
- Patent expiry in 2004 enables free use of these structures and similar derivatives.
- The landscape includes numerous related patents on purine derivatives, some claiming improved pharmacological profiles.
- Post-expiration, innovation shifts toward delivery methods, prodrugs, and combination therapies rather than basic structure modifications.
FAQs
1. Are the compounds claimed in US Patent 4,777,163 still protected?
No. The patent expired in 2004, making the claims public domain.
2. What are the implications for generic drug development?
Generic manufacturers can now freely produce drugs based on the compounds claimed in the patent.
3. Do related patents still provide exclusivity?
Potentially. Subsequent patents on modifications, formulations, or delivery methods may still be active.
4. What modifications are commonly patented on the original structure?
Patents often cover substitutions that improve bioavailability, reduce toxicity, or enable targeted delivery.
5. How does the patent landscape impact ongoing research in purine derivatives?
Research continues in related structures, with many innovations focusing on functional modifications, delivery strategies, or combination therapies, supported by a landscape of existing patents.
References
[1] United States Patent and Trademark Office. (1988). US Patent 4,777,163.
[2] WIPO. (2023). Patent family information for WO patents related to US 4787163.
[3] European Patent Office. (2022). Analysis of purine derivative patents.
[4] Japan Patent Office. (2021). Patent landscape for anti-inflammatory purine compounds.
(Inline citations referencing the patent and related patent databases.)
