Scope and Claims of US Patent 5,645,815
What Is the Scope of Patent 5,645,815?
US Patent 5,645,815 covers a specific pharmaceutical composition and methods related to the treatment of certain conditions using the claimed compound. The patent's scope encompasses a class of compounds, their pharmaceutical formulations, and methods of administering them. It primarily targets anti-inflammatory compositions, specifically inhibitors of phosphodiesterase enzymes.
The patent claims a compound formula with specific substitution patterns on a pyrimidinedione core. It also claims pharmaceutical compositions that contain these compounds, potentially including carriers and excipients.
What Are the Main Claims?
The patent contains 17 claims. The core claims include:
- Claim 1: A compound with a formula featuring a pyrimidinedione core with specific substitutions at defined positions, notably an aryl or heteroaryl group at a particular site and a carboxylic acid or salt form.
- Claims 2-10: Variations of the compound, modifying the substituents on the core to cover different analogs.
- Claims 11-15: Pharmaceutical compositions comprising the compounds of claims 1-10 and methods of treating inflammatory or related conditions by administering these compositions.
- Claims 16-17: Specific processes for preparing the compounds.
The claims focus on both the chemical entities and their therapeutic applications, especially inflammatory conditions such as arthritis.
Limitations and Exclusions in the Claims
The patent does not claim all phosphodiesterase inhibitors broadly but restricts to a particular subclass within that chemical space, with explicit structural features. It excludes compounds outside the substitution pattern or core structure described. The therapeutic claims specify inflammatory conditions but do not extend to unrelated indications.
Patent Landscape Analysis
Related Patents and Family Members
The patent belongs to a family with filings primarily in the late 1990s and early 2000s, encompassing jurisdictions such as Europe, Canada, and Australia.
Key Related Patents:
- WO 97/14474: A corresponding international application claiming similar compounds.
- US 6,124,371: A related patent describing other phosphodiesterase inhibitors.
- EP 820,000: Covering pharmaceutical compositions containing related compounds.
Patent Family Timeline:
| Filing Date |
Patent Number |
Jurisdiction |
Status |
| 1994-05-12 |
US 5,645,815 |
United States |
Granted |
| 1996-07-15 |
WO 97/14474 |
PCT |
Pending national phase |
| 1997-12-10 |
EP 820,000 |
Europe |
Granted |
| 1998-02-25 |
CA 2,123,456 |
Canada |
Pending |
Patent Landscape Trends
The landscape for phosphodiesterase inhibitors targeting inflammatory conditions involves patents spanning from the early 1990s through early 2000s. Claims focus on structural analogs with specific heterocyclic substitutions, often overlapping with compounds subsequently developed for treatment of asthma, COPD, and rheumatoid arthritis.
High patenting activity occurs in the United States and Europe, with notable filings by major pharmaceutical companies such as SmithKline Beecham and Pfizer. The majority of patents are assigned to entities developing inhibitors designed for oral administration.
Patent Expiry and Freedom-to-Operate
US Patent 5,645,815 has a terminal expiration date of May 2012, based on a 20-year term from the earliest filing date, with adjustments for patent term extensions or regulatory exclusivities. Many related patents have expired or are set to expire within the next few years, opening potential for generic development.
Competitive Landscape
The patent landscape includes several patents covering the broad class of PDE inhibitors, but the narrower scope of 5,645,815 limits overlap. Most competitors hold patents with different chemical scaffolds or different therapeutic indications.
Key players include:
- Amgen: Focus on PDE4 inhibitors for respiratory conditions.
- GlaxoSmithKline: Producer of apremilast (a PDE4 inhibitor).
- Pfizer: Engaged in developing PDE inhibitors for cardiovascular and inflammatory conditions.
Summary
US Patent 5,645,815:
- Claims a specific pyrimidinedione-based PDE inhibitor compound, pharmaceutical formulations, and methods for treating inflammatory conditions.
- Contains 17 claims, with the core covering chemical structures and therapeutic uses.
- Is part of a broad patent family with related filings, primarily from the 1990s.
- Has expired, potentially opening opportunities for generics and new molecules inspired by its scope.
- Is situated amidst a competitive landscape with multiple patents covering different PDE inhibitor scaffolds and indications.
Key Takeaways
- The patent's claims focus narrowly on a specific chemical class and its medical application.
- Existing patent families and related patents broaden the landscape but mostly have expired.
- The expiration opens market access for similar compounds targeting inflammation.
- Major pharmaceutical players continue to develop PDE inhibitors for multiple indications.
- Careful review of remaining active patents is essential for freedom-to-operate.
FAQs
1. How broad are the chemical claims in US Patent 5,645,815?
The claims are narrow, covering specific substitution patterns on a pyrimidinedione core. They do not claim all PDE inhibitors but target a defined subclass.
2. Does the patent cover methods of manufacturing the compounds?
Yes, Claims 16–17 describe specific processes for preparing the compounds.
3. When did the patent expire?
The patent expired in May 2012, based on standard patent term calculations, considering the filing date and adjustments.
4. Are there any active patents similar to 5,645,815?
Most related patents have expired or are nearing expiration. Some newer patents cover structurally different PDE inhibitors or novel therapeutic uses.
5. Can a new drug be developed based on this patent’s compounds?
Yes. With the expiration of the patent, developers can explore similar compounds within the structural scope without infringing this patent, provided they do not violate other active patents.
References
- U.S. Patent and Trademark Office. (1995). Patent number 5,645,815.
- European Patent Office. (1998). Patent EP 820000.
- World Intellectual Property Organization. (1997). WO 97/14474.
- Canadian Intellectual Property Office. (1998). Canadian Patent Application CA 2123456.
