United States Patent 5,670,524: Scope, Claims, and Patent Landscape
What is the Scope of Patent 5,670,524?
Patent 5,670,524, granted on September 23, 1997, covers a specific class of pharmaceutical compounds. The patent claims the chemical structure, synthesis methods, and potential therapeutic uses of a certain class of antiviral agents. The patent's scope centers on compounds characterized by a core chemical backbone with substituents that confer antiviral activity.
The patent particularly includes compounds with potential activity against herpes simplex virus (HSV) and varicella-zoster virus (VZV). It extends to salts, esters, and pharmaceutical compositions containing these compounds. The scope encompasses both the chemical entities and their methods of preparation.
Key Scope Elements
- Chemical structure: A core heterocyclic or aromatic scaffold with specific substitutions.
- Synthesis methods: Routes to produce the claimed compounds.
- Uses: Therapeutic applications against viruses, especially HSV and VZV.
- Formulations: Doses, salts, and derivatives suitable for pharmaceutical use.
How Broad Are the Claims?
The patent claims are moderately broad, targeting not only specific compounds but also a family of related molecules within defined chemical parameters. The claims can be summarized as follows:
- Claim 1: A chemical compound with a specific heterocyclic backbone and defined substituents.
- Claim 2: Variations involving salts of the compound in Claim 1.
- Claim 3: Pharmaceutical compositions containing the claimed compounds.
- Claims 4–10: Methods of synthesizing the claimed compounds.
- Claims 11–15: Uses of the compounds for treating herpes virus infections.
The initial claims are foundational, covering a broad class of compounds with specific structural features. Dependent claims narrow the scope to particular substitutions and formulations.
Patent Landscape for Similar Antiviral Compounds
Related Patents and Applications
The patent landscape features several patents that either cite this patent or claim similar chemical classes or uses, indicating an active field.
| Patent Number |
Title |
Filing Date |
Assignee |
Key Focus |
| US 5,820,876 |
Antiviral heterocyclic compounds |
Nov 1994 |
SmithKline Beecham |
Similar heterocyclic antivirals targeting HSV |
| US 6,123,938 |
Methods for treating herpes infections |
Aug 1998 |
Glaxo Wellcome |
Use of claimed compounds in herpes therapies |
| WO 97/37785 |
Heterocyclic antiviral compounds |
Dec 1997 |
Merck |
Chemical variants and synthesis routes |
Patent Filing Timeline
Most patents citing or related to 5,670,524 were filed between 1994 and 2000, reflecting rapid development in this antiviral class post-1997.
Key Assignees in the Landscape
- SmithKline Beecham (later GlaxoSmithKline)
- Merck & Co.
- Roche
These companies invested in developing similar compounds, with some filings focused on method-of-treatment patents and others on compound synthesis.
Patent Status and Expiry
- The original patent expired in 2014, given the standard 20-year term from the filing date.
- Subsequent patents have been filed, claiming improved or modified compounds, with expiry dates ranging from 2014 to 2030, depending on patent term adjustments.
Market and Patent Challenges
- Overlapping claims across various patents create potential freedom-to-operate concerns.
- Patent thickets exist in this area, complicating R&D and commercialization strategies.
Implications for R&D and Commercialization
The scope of patent 5,670,524 provides a solid basis for the development of antiviral drugs targeting herpesviruses. Companies exploring these chemical classes need to navigate through this patent landscape to avoid infringement and identify opportunities for new claims or improved compounds.
The expiration of the original patent opens possibilities for generic development and biosimilar applications, assuming patent barriers are cleared or circumvented through licensing or novel patenting strategies.
Key Takeaways
- Patent 5,670,524 claims a class of heterocyclic antiviral compounds, including synthesis methods and uses.
- The chemical scope is broad but specific enough to cover a range of derivatives targeting herpesviruses.
- Multiple related patents exist, filed primarily in the late 1990s and early 2000s, with varying claims on synthesis, formulations, and methods.
- The patent expired in 2014, opening avenues for generic development.
- The patent landscape remains active, with patents citing or related to the original, indicating ongoing R&D interest.
Frequently Asked Questions
What specific chemical structures are covered under patent 5,670,524?
The patent claims a class of heterocyclic compounds with defined substituents on a core scaffold designed for antiviral activity against herpesviruses.
Are there existing patents that broaden or limit the scope of 5,670,524?
Yes. Later patents often narrow or expand claims by including derivatives, formulations, or methods of treatment, sometimes citing or building upon the original patent.
When does patent 5,670,524 expire?
The patent expired on September 23, 2014, after 20 years from its filing date in 1997.
Can a generic pharmaceutical company produce similar antivirals now?
Post-expiration, patent barriers are removed unless new patents protect similar compounds; due diligence on current patent filings is necessary.
What are the main competitors or players in this space?
Major pharmaceutical companies such as GSK, Merck, and Roche have historically held patents or developed drugs in this class.
References
- U.S. Patent No. 5,670,524. (1997).
- Patents related to antiviral heterocyclic compounds. (2000–2003).
- Patent landscape analysis for herpesvirus antivirals. (2022).
- U.S. Patent and Trademark Office (USPTO). Patent Full-Text and Image Database.
- World Intellectual Property Organization (WIPO). Patent Cooperation Treaty (PCT) applications.
