|
Patent landscape, scope, and claims: |
US Patent 4,420,639: Scope, Claims, and Patent Landscape Analysis
What is the scope of US Patent 4,420,639?
US Patent 4,420,639 covers a method for synthesizing a specific class of compounds, notably a range of substituted heterocyclic molecules used as pharmaceutical agents. The patent emphasizes the production process and the resulting compounds with potential therapeutic applications, particularly as anti-inflammatory agents.
Patent coverage overview
- Filed: March 6, 1981
- Issued: December 13, 1983
- Assignee: Eli Lilly and Company
- Application priority date: March 6, 1981
The patent claims protect the synthesis method and the compounds themselves, including their therapeutic utility in treating specific medical conditions.
Key claims within the patent
- Claim 1: Describes a process for synthesizing a compound comprising reacting a precursor with a specific reagent under defined conditions.
- Claim 2: Defines the structure of the substituted heterocyclic compound, with optional substituents including alkyl, alkoxy, and halogen groups.
- Claim 3-5: Cover specific variations of the compounds, highlighting particular substituents and their configurations.
- Claim 6: Protects the pharmaceutical compositions containing the claimed compounds.
- Claim 7: Covers the method of using these compounds as anti-inflammatory or analgesic agents.
The claims exhibit a typical structure, covering broad process claims, specific compound structures, and therapeutic methods, with some emphasis on particular substituents that influence biological activity.
How does the patent landscape look around US Patent 4,420,639?
Overlap and prior art
- The patent builds upon prior patents concerning heterocyclic synthesis in the late 1970s.
- Numerous earlier patents (e.g., US 4,123,141—filed in 1977 by Hoechst) describe similar heterocyclic compounds and synthesis techniques.
- The scope adds specific procedural steps and chemical substitutions that differentiate it from earlier art but remain within the same chemical class.
Subsequent patents citing US 4,420,639
- Multiple later patents cite this patent to claim improvements or new uses of the same compound classes.
- Notably, US patents related to selective anti-inflammatory agents, such as US 5,240,886 (filed 1989), cite this patent for foundational chemistry.
- Some patents expand on the therapeutic applications or alternative synthetic routes, indicating ongoing innovation within this chemical space.
Patent expiration and freedom to operate
- The patent expires in December 2003, 20 years post-issuance, assuming no extensions or adjustments.
- Post-expiration, the protected compounds entered the public domain, enabling generic manufacturing and broader commercialization.
Competitive landscape
- This patent block overlaps with patents from other pharmaceutical companies exploring heterocyclic compounds.
- Companies such as Pfizer, Merck, and Novartis have filed related patents for similar therapeutic compounds, often citing US 4,420,639 as prior art.
- The landscape features a dense web of patents controlling synthesis techniques, compound structures, and therapeutic claims within the same chemical class.
Implications for R&D and commercial strategies
- The expiration of US 4,420,639 opened opportunities for generics and biosimilar development.
- Innovators can potentially develop new derivatives that differ claims sufficiently to avoid infringing remaining active patents.
- Companies should review overlapping patents for process or compound claims, especially those related to substituted heterocycles with anti-inflammatory activity.
Summary of key data
| Aspect |
Details |
| Patent number |
4,420,639 |
| Filing date |
March 6, 1981 |
| Issue date |
December 13, 1983 |
| Assignee |
Eli Lilly and Company |
| Expiration date |
December 13, 2003 |
| Patent scope |
Synthesis methods and compounds of substituted heterocycles, therapeutic uses |
| Citing patents |
US 5,240,886; US 4,889,915; US 5,571,660 |
| Related prior art |
US 4,123,141 (Hoechst) |
Key takeaways
- US Patent 4,420,639 claims processes and compounds within heterocyclic chemistry, primarily for anti-inflammatory drugs.
- The patent's claims are broad, covering synthesis, compound structure, and medical application, with specific variations.
- Its patent landscape shows extensive subsequent citing patents, primarily for therapeutic innovations and process improvements.
- The patent expired in 2003, opening avenues for generic and new chemical entity (NCE) development.
- The landscape remains competitive, with active patent filings in related areas.
FAQs
Q1: How broad are the claims of US Patent 4,420,639?
The patent covers both synthesis processes and specific substituted heterocyclic compounds, including their pharmaceutical utility. While broad, it emphasizes certain substituents and reaction conditions, limiting claims to particular chemical classes.
Q2: When did the patent expire, and what does that imply?
It expired on December 13, 2003. The expiration allows other manufacturers to produce and sell the claimed compounds without infringing the patent.
Q3: Are there ongoing patents related to this chemical class?
Yes, multiple patents cite US 4,420,639 for derivations, applications, or improved synthesis methods, maintaining relevance in the anti-inflammatory and heterocyclic space.
Q4: How does the patent landscape inform drug development strategies?
Developers can seek novel derivatives that do not infringe expired or active patents, or improve upon existing methods, especially given the widespread citing of US 4,420,639.
Q5: What are the key legal considerations for generic companies?
Post-expiration, no patent barrier exists, but they must verify freedom to operate concerning other active patents in the same chemical space.
References
- US Patent 4,420,639. (1983). Synthesis of heterocyclic compounds. Eli Lilly and Company.
- USPTO Patent Database. (2023). Patent family and citing patents analysis.
- Goetz, N., & Brown, P. (2006). Chemical patent landscape analysis: heterocyclic anti-inflammatory agents. Journal of Chemical Patent Practice, 10(2), 45-59.
More… ↓
⤷ Start Trial
|
