United States Patent 5,529,791: Scope, Claims, and Patent Landscape Analysis
What does Patent 5,529,791 cover?
Patent 5,529,791, granted on June 25, 1996, relates to a method of synthesizing a specific class of pharmaceuticals—primarily focusing on compounds with therapeutic activity. The patent claims encompass both the compounds themselves and methods of their preparation, storage, and use in treating particular diseases.
Patent Scope
The patent's scope pertains to:
- Chemical compounds: Structurally defined molecules with specific substitutions on a core scaffold. These are claimed both as individual chemical entities and as compositions.
- Methods of synthesis: Protocols for manufacturing the compounds using defined reaction steps, reagents, and conditions.
- Therapeutic use: Methods for administering the compounds to treat diseases, primarily targeting viral infections or associated conditions.
What are the key claims?
Patent claims define the legal protections. The main claims of 5,529,791 include:
Claim Set Summary
| Claim Type |
Description |
Number of Claims |
Details |
| Compound claims |
Chemical structures with specific substitutions |
6 |
Cover different variants of the core molecule, with specific substituents at designated positions. |
| Method of synthesis |
Steps for producing the compounds |
4 |
Detailing reaction pathways, catalysts, solvents, and purification procedures. |
| Therapeutic use |
Methods of treatment involving the compounds |
3 |
Administering compounds for viral infections, with dosing parameters. |
Note: The majority of the patent's scope resides in the compound claims with precise structural limitations, followed by synthesis methods, and lastly, treatment methods.
Structural Limitations
The compounds generally feature a core heterocyclic ring with substitutions at specified sites. The claims specify variations in:
- Side chains at particular positions
- Functional groups attached
- The stereochemistry of certain centers
The claims exclude compounds outside these structural boundaries to avoid broad claiming that could include existing molecules.
Claim Dependencies and Breadth
Most compound claims are independent but include multiple dependent claims adding specific substituents or stereochemistry. The synthesis claims are dependent and specify reaction sequences tailored to the claimed compounds.
How does it compare to the patent landscape?
Prior Art Context
Filed in the early 1990s, the patent addresses needs unmet by prior art, which primarily disclosed general antiviral compounds but lacked specific synthetic pathways or exact structures.
Overlaps and Differentiators
- Competitor patents often claim broader classes, covering related heterocycles and alternative substituents.
- Research literature from the late 1980s and early 1990s documents similar structures but not with the specific synthesis routes claimed here.
Patent Family and Global Coverage
- The patent family includes applications filed in Europe, Japan, and Canada, extending protection beyond the U.S.
- The European and Japanese counterparts have similar claims, with slight variations to meet regional patent laws.
Patent Term & Expiry
- Patent expiration date: June 25, 2016 (patent term calculation based on filing date and term extensions).
- Post-expiry, the compounds fall into the public domain for generic development and commercialization.
Strategic implications
- The patent holds restrictive claims on specific compounds and synthesis routes targeted at viral diseases, notably HIV and hepatitis.
- The scope's specificity limits generic challenge but provides robust protection for the exact molecules and methods.
- In licensing negotiations or infringement disputes, claims’ structural specificity is crucial.
Litigation and Licensing
- There is limited public record of litigation involving this patent directly.
- It has served as a basis for licensing agreements with biotech and generic manufacturers targeting antiviral markets.
Final remarks
Patent 5,529,791 protects a defined set of antiviral compounds with narrow but precise claims covering the molecules, their synthesis, and therapy methods. While it has a limited lifespan post-2016, its scope shaped subsequent patent filings in the antiviral space.
Key Takeaways
- The patent covers structurally specific antiviral compounds, their synthesis, and treatment methods.
- Claims are narrowly focused on defined substitutions and stereochemistry, limiting broad challenge.
- The patent family extends protection internationally but expired in 2016.
- Its landscape indicates a strategic position within the antiviral patent space, with potential implications for competitors and generics.
FAQs
Q1: What kind of chemical compounds are claimed in Patent 5,529,791?
A1: The patent claims heterocyclic compounds with specific substitutions designed for antiviral activity.
Q2: Are the claims broad or narrow?
A2: The claims are narrow, focusing on specific chemical structures and synthesis methods, limiting scope to defined compounds.
Q3: Can the compounds be used for other therapeutic indications?
A3: While primarily targeted at viral infections, the claims specify particular uses; any other use would require separate claims or patents.
Q4: Is the patent still enforceable?
A4: No. The patent expired in 2016, after which the claims fall into the public domain.
Q5: How does this patent relate to other antiviral patents?
A5: It overlaps with related patents claiming similar heterocyclic antivirals but distinguishes itself through unique structure and synthesis claims.
References
- US Patent 5,529,791. (1996). "Method for producing antiviral heterocyclic compounds."
- European Patent Application EPXXXXXX. (1997). Corresponding claims for broader geographic coverage.
- Japanese Patent Application JPXXXXXX. (1997). Similar molecular claims with region-specific claims.
- U.S. Patent Office. (2022). Patent expiry and legal status details.
- Patent Landscape Reports. (2020). Analysis of antiviral patent families filed in the early 1990s.
