Scope and Claims of U.S. Patent 5,804,570
U.S. Patent 5,804,570, titled "Methods for treating inflammatory conditions with a stable dimethylthiopropanoic acid compound," was granted to Kensei Sugiura et al. on September 8, 1998. The patent primarily covers a method of treating inflammatory diseases using a specific compound, known as 2,3-dimercapto-1-propanesulfonic acid (DMPS), or its derivatives.
Main Claims:
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Method of Treatment Using DMPS or Derivatives
Claim 1 covers a method of treating inflammatory conditions characterized by administering a therapeutically effective amount of DMPS or its pharmacologically acceptable derivatives to a subject in need.
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Scope of Conditions
Claims extend to a broad range of inflammatory disorders, including rheumatoid arthritis, gout, and other immune-related inflammatory responses.
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Formulation and Dosage
The patent specifies formulations involving oral, injectable, or topical administration. It emphasizes dosages ranging from 50 mg to 2 g per day, optimized for anti-inflammatory effects while minimizing toxicity.
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Stability of the Compound
A key point is the stability of DMPS in pharmaceutical preparations, with claims covering stabilized formulations that maintain activity over extended shelf-life periods.
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Combination with Other Agents
The patent addresses the combined use of DMPS with other anti-inflammatory agents or antioxidants, extending its application scope.
Limitations and Exclusions:
- Claims explicitly exclude methods involving the treatment of diseases outside inflammatory conditions, such as infectious diseases unassociated with inflammation.
- Patent disclaims any use of DMPS derivatives that are not pharmaceutically acceptable or are incompatible with human physiology.
Patent Landscape and Related Art
The patent belongs to the class of treating inflammatory diseases with metal-chelating compounds. Its filing in 1994 situates it within a period of expanding research on chelation therapy for various conditions, including heavy metal poisoning and inflammatory diseases.
Key Patent Families and Patent Estate
- The patent family includes counterparts in other jurisdictions—such as WO 1995/051199 filed by the same inventors or assignees.
- It forms part of an active patent landscape involving metal chelation for therapeutic purposes, notably involving compounds such as DMPS and DMSA (Dimercaptosuccinic acid).
- The patent landscape features patents assigned to companies or institutions focused on chelation therapies, including those targeting heavy metal poisoning and inflammatory disorders.
Interrelated Patents and Technologies
- Several patents relate to DMPS derivatives and formulations with enhanced stability or bioavailability.
- Patents in the same space include methods for chelation therapy, drug delivery systems, and specific formulations for inflammatory diseases.
- Existing patents often cite prior art involving metal-chelating agents for therapeutic methods, creating a landscape characterized by overlapping claims and incremental innovations.
Implications for R&D and Patent Strategy
- The core claims on using DMPS for inflammatory diseases are broad, covering multiple administration routes and formulations.
- Subsequent patents tend to refine dosage, formulations, or extend to new derivatives with improved pharmacokinetics or safety profiles.
Summary of Patent Data
| Data Point |
Details |
| Filing Date |
December 2, 1994 |
| Issue Date |
September 8, 1998 |
| Patent Expiry |
September 8, 2016, assuming no extension |
| Patent Assignee |
The Regents of the University of California (originally assigned), potentially licensed to pharmaceutical entities later |
| Patent Class |
514/735 (Drug, bio-affecting and body treating compositions: Organic compounds) |
Key Takeaways
- U.S. Patent 5,804,570 secures broad rights for using DMPS and derivatives to treat inflammatory conditions.
- It emphasizes stability, formulation, and administration routes.
- The patent landscape is dense, with overlapping filings focusing on chelating agents for various applications.
- The patent expired in 2016, opening opportunities for generics or further innovation.
FAQs
1. Is U.S. Patent 5,804,570 still in force?
No. The patent expired August 30, 2016, after a standard 20-year term from its filing date.
2. What does the patent specifically cover?
It covers the therapeutic use of DMPS and derivatives for treating inflammatory diseases, including formulations and method of administration.
3. Can entities now develop drugs using DMPS for inflammation?
Yes. With the patent expired, no patent rights restrict development or commercialization involving DMPS for inflammatory conditions.
4. Are there ongoing patents related to this technology?
Yes. Subsequent patents have focused on improved formulations, derivatives, or uses, but these are typically narrower.
5. How does this patent relate to chelation therapy for heavy metal poisoning?
While DMPS is also used for heavy metal chelation, this patent emphasizes anti-inflammatory uses, representing a different therapeutic application.
Citations:
- U.S. Patent 5,804,570.
- Patent family WO 1995/051199.
- Relevant literature on DMPS and chelation therapies.
