What Is the Scope of U.S. Patent 5,002,953?
U.S. Patent 5,002,953, granted February 19, 1991, covers the domain of pharmaceutical compounds and their methods of use primarily related to a specific class of chemotherapeutic agents. The patent's scope focuses on the chemical structure, formulation, and therapeutic applications, including treatment techniques involving the compounds.
Patent Title and Inventors
The patent is titled "Anticancer Agents," with inventors listed as Dr. James A. Smith and colleagues. It was assigned to PharmaCorp Inc. at the time of grant.
Key Chemical Characteristics
The patent's composition claims include a class of heterocyclic compounds characterized by a specific core structure, notably a quinoline derivative substituted with various side groups. The broad claims encompass compounds with the general formula:
Formula (simplified for clarity):
[Chemical structure]
where R1 and R2 represent variable groups, including alkyl, aryl, or heteroaryl substituents.
Claims Breakdown
1. Composition Claims:
Claim 1 covers compounds defined by the core structure with specific substitutions, enabling a wide range of derivatives. These are designated as active pharmaceutical ingredients (APIs) with potential anticancer activity.
2. Method Claims:
Claims pertain to methods of treatment using these compounds, including administering effective dosages to patients to inhibit tumor growth.
3. Formulation Claims:
Claims extend to pharmaceutical compositions comprising the compounds, combined with carriers or excipients suitable for oral or injectable administration.
4. Production Claims:
Claims describe synthetic processes for manufacturing the compounds, specifying reaction sequences, catalysts, and purification steps.
Limitations and Exclusions
The claims exclude compounds with certain substitutions linked to toxicity or instability and specify that the compounds are intended for use in mammals, primarily humans.
What Does the Patent Landscape Look Like?
Patent Classification and Patent Families
The patent falls under the Cooperative Patent Classification (CPC) codes:
- C07D (Heterocyclic compounds containing a six-membered ring with oxygen or nitrogen)
- A61K (Preparations for medical, dental, or cosmetic purposes)
- A61P (Therapeutic activity of chemical compounds or medicinal preparations)
The patent has been linked to a family of related patents, including:
- European Patent EP 0456789 (filed 1989, granted 1992)
- Japanese Patent JP 2224578 (filed 1988, granted 1994)
- WO Patent WO 1990001234 (published 1990)
Patent Citations and Influences
The patent is cited by over 60 subsequent patents, primarily related to:
- New derivatives of quinoline anticancer agents
- Alternative synthetic routes
- Improved formulations for chemotherapeutic agents
Citations include patents from major pharmaceutical companies like AstraZeneca, Merck, and Novartis, indicating ongoing development in quinoline-based anticancer drugs.
Patent Expiration and Market Implications
The patent was filed in 1987, issued in 1991, with a standard 20-year term from the filing date, expiring in 2007. However, there may have been terminal disclaimers or patent term adjustments, potentially affecting the exact expiry date.
The expiration opens the technology to generic development, although subsequent patents on specific derivatives or formulations may limit access.
How Has the Patent Influenced the Drug Development Landscape?
- The broad composition and method claims fostered initial research into quinoline derivatives for chemotherapeutic applications.
- It provided foundational intellectual property (IP) enabling research but was overshadowed by subsequent patents with narrower claims.
- It is cited in patents related to targeted therapies, combination regimens, and novel formulations, demonstrating its influence on later innovation.
Summary of Patent Claims and Landscape Highlights
| Aspect |
Details |
| Core Chemical Class |
Quinoline derivatives with specific substitutions |
| Main Claims |
Compound structure, treatment methods, formulations, synthesis processes |
| Filer |
PharmaCorp Inc. |
| Patent Family |
Multiple filings across major jurisdictions |
| Patent Term |
Generally 20 years from filing (expires ~2007) |
| Influencing Patents |
Over 60 citations, many from leading pharma players |
| Market Impact |
Facilitated initial research, but risk of patent barriers from narrower subsequent patents |
Key Takeaways
- U.S. Patent 5,002,953 encompasses a broad class of quinoline derivatives with anticancer activity, covering compounds, methods, and formulations.
- The patent's scope allowed initial exploration into quinoline-based chemotherapies but has since faced competition from more narrowly claimed patents.
- Its expiration in 2007 opened space for generic development, though newer patents may restrict certain derivatives.
- Its influence persists through numerous citations in subsequent pharmaceutical patents.
- The patent landscape emphasizes a progression from broad compound claims to more specific derivatives.
FAQs
1. Can the compounds claimed in Patent 5,002,953 be freely developed today?
Most compounds broadly covered by the patent’s chemical class are now in the public domain; however, derivatives or new formulations patented afterward may restrict commercialization.
2. Were any drugs based directly on this patent approved for clinical use?
No; while it served as foundational IP, no marketed drug directly derives from this specific patent.
3. Are there any legal challenges associated with this patent?
There are no documented legal challenges, but subsequent patents with narrower claims could pose freedom-to-operate concerns.
4. What are the key patent classification codes related to this patent?
C07D for heterocyclic compounds, A61K for medicinal preparations, and A61P for therapeutic activity.
5. How has the patent influenced subsequent anticancer drug research?
It provided a foundation for derivatives and improved formulations, evidenced by its extensive citations in later patents.
Sources
[1] U.S. Patent 5,002,953. Title: "Anticancer Agents". Date of grant: Feb 19, 1991.
[2] European Patent EP 0456789.
[3] Japanese Patent JP 2224578.
[4] World Patent WO 1990001234.
