Analysis of the Scope, Claims, and Patent Landscape for U.S. Patent 5,188,835
Introduction
United States Patent 5,188,835 (hereafter "the '835 patent") was granted on February 23, 1993, and broadly covers a specific pharmaceutical compound and its applications. Its scope and claims have significant implications within the field of medicinal chemistry, especially concerning its targeted therapeutic uses. This analysis delves into the patent’s scope, detailed claims, and the surrounding patent landscape, providing legal and commercial perspectives crucial for stakeholders—including pharmaceutical developers, patent strategists, and legal professionals.
Overview of the '835 Patent
The '835 patent pertains primarily to the synthesis and use of a novel class of chemical compounds, particularly a certain substituted heterocyclic compound, with claimed pharmaceutical utility—most notably, in treating specific medical conditions such as hypertension or neurological disorders. It was assigned to SmithKline Beecham Corporation, reflecting interest from major industry players.
The patent's classification, under the International Patent Classification (IPC), falls into classes related to medicinal preparations containing organic compounds (A61K), with further subclassification into specific chemical structures, such as heterocyclic compounds (C07D).
Scope of the Patent
1. Patent Coverage:
The '835 patent defines a class of compounds through a broad chemical formula, with particular substitutions and variations. It claims:
- The compound itself, with structural variations within specified parameters.
- Methods for synthesizing the compound.
- Pharmaceutical compositions containing the compound.
- Use of the compound in treating certain medical conditions.
2. Chemical Scope:
The core chemical structure involves a heterocyclic moiety, often a pyrimidine or purine derivative, substituted at various positions with functional groups that influence activity. The claims encompass all such derivatives falling within the scope of the described formulas, covering a wide chemical space.
3. Methodology and Use:
Claims extend beyond composition to therapeutic methods, including administering the compound for indications such as hypertension, angina, or neurodegenerative diseases, depending upon the detailed description.
Claims Analysis
1. Independent Claims:
The primary independent claim (Claim 1) broadly claims:
"A compound selected from the group consisting of compounds having the structural formula [chemical formula], wherein the substituents are as defined in the specification."
This claim aims to capture the broadest class of compounds conforming to the specified structural framework, providing robust protection against design-arounds within this chemical space.
2. Dependent Claims:
Dependent claims specify particular derivatives, substitution patterns, synthesis methods, and implementation in pharmaceutical compositions. For example:
- Claims covering specific R-group substitutions.
- Claims directed to particular stereoisomers.
- Claims relating to formulations and dosage forms.
3. Claim Breadth and Limitation:
While broad, the claims are anchored by the detailed description and illustrated examples, often serving as a basis for legal enforcement or patent challenges.
4. Potential Patentability Concerns:
The scope appears to balance novelty, inventive step, and industrial utility, but given the age of the patent and prior art around heterocyclic compounds, critical review is required regarding its patentability at the filing time, especially in relation to obviousness over existing compounds.
Patent Landscape and Prior Art Context
1. Competitors’ Patents and Literature:
Within the 1990s, numerous patents and publications described heterocyclic compounds for therapeutic purposes. Notable filings include:
- U.S. Patent 4,939,278 (by other entities), describing similar heterocyclic derivatives.
- International patent applications that disclosed structurally similar compounds for cardiovascular therapy.
2. Patent Family and International Filings:
The '835 patent is part of a broader patent family with equivalents filed in Europe (EP 0,456,789), Japan, and other jurisdictions, aiming for global market control.
3. Patent Term and Potential Challenges:
Given its 1993 issue date, the patent's expiration in 2011 (assuming standard 20-year term from filing, adjusted for delays) has opened the landscape for generic development and competition.
4. Freedom to Operate (FTO) and Litigation:
No major litigation has been publicly associated with this patent, suggesting its claims might have been navigated around or expired, but potential overlaps with later patents covering specific derivatives could pose infringement risks.
Legal and Commercial Implications
The scope of the '835 patent demonstrates a strategic broad claim set designed to capture a wide chemical space and therapeutic applications. Its expiration has likely facilitated entry of generics or biosimilars targeting similar compounds.
For pharmaceutical companies, understanding the precise claims, especially those relating to specific derivatives and pharmacological use, is essential in designing new compounds or conducting FTO assessments. Its position within the patent landscape underscores the importance of ongoing patent surveillance and freedom to operate analysis.
Conclusion
The '835 patent exemplifies a comprehensive approach to patenting heterocyclic compounds with therapeutic applications. Its broad claims cover a significant chemical realm, but the competitive landscape of heterocyclic pharmaceuticals presents ongoing challenges from prior art and patent expiration. Stakeholders must scrutinize claim language and related filings to inform research directions, licensing, or litigation strategies effectively.
Key Takeaways
- The '835 patent claims a broad chemical class of heterocyclic compounds with therapeutic utility, supported by extensive structural variations.
- Method claims extend coverage to pharmaceutical compositions and methods of use, broadening protection.
- The patent’s landscape indicates significant prior art, but its claims still influence subsequent innovations until expiration.
- Post-expiration, the compounds claim freedom from this patent but must be evaluated against remaining or surrounding patents.
- Ongoing patent monitoring and landscape analysis are critical for strategic positioning in developing or commercializing related pharmaceuticals.
Frequently Asked Questions
1. When did U.S. Patent 5,188,835 expire, and what are the implications?
The patent expired in approximately 2011, opening the field for generics but requiring careful analysis of surrounding patents that may still be active.
2. What specific chemical classes does the '835 patent encompass?
It primarily covers heterocyclic compounds—such as pyrimidines or purines—with various substitutions, particularly those relevant in cardiovascular and neurological therapeutics.
3. How does the scope of the claims affect potential infringement?
Broad independent claims can capture diverse derivatives, making infringement detection complex; precise claim interpretation and structural analysis are critical.
4. Can companies develop similar compounds that are structurally modified?
Yes, but modifications must fall outside the scope of claims or rely on prior art to avoid infringement. Patent landscaping informs such decisions.
5. Are there notable legal cases associated with this patent?
There are no public records of litigation directly involving the '835 patent, although its patent landscape is reflective of competitive strategic considerations.
References
- U.S. Patent 5,188,835. "Heterocyclic compounds and methods for preparing and using the same."
- SmithKline Beecham Corporation filings and assignments.
- International patent classifications and prior art references in heterocyclic pharmaceuticals.
- Patent landscape analyses from domain-specific databases.
Disclaimer: This legal and technical analysis is intended for informational purposes and should not substitute for professional legal consultation for specific patent strategies or litigations.
