Summary
Patent 5,635,172 pertains to a pharmaceutical composition and method involving a specific class of drugs. Its scope centers on a particular formulation or method of treatment. The patent claims define the boundaries of protection, primarily concerning specific compounds, compositions, and their therapeutic use. The patent landscape includes filings, expirations, and related patents that either build on or challenge the patent’s claims.
What is the Scope of U.S. Patent 5,635,172?
Patent Overview:
Issued on June 3, 1997, to Eli Lilly and Company, patent 5,635,172 protects a method involving a class of benzodiazepine derivatives used for treating anxiety, depression, or other nervous system disorders.
Main Claim Types:
- Compound Claims: Cover specific chemical entities; for instance, benzodiazepine derivatives with particular substitutions.
- Method Claims: Cover the administration of the compound for treating certain conditions.
- Composition Claims: Cover pharmaceutical formulations containing the compound.
Key Features of Claims:
- Chemical structures primarily based on benzodiazepine rings.
- Specific substitutions at certain positions to enhance therapeutic effect or reduce side effects.
- Use of the compound in treating anxiety, insomnia, or related disorders.
Scope Limitations:
- The claims are limited to compounds with the particular substitutions specified in the patent.
- The therapeutic methods are limited to administration for specified indications.
- The patent does not broadly cover all benzodiazepine derivatives outside the claimed structures.
How Extensive Are the Claims?
| Claim Type |
Number of Claims |
Scope Description |
Notable Aspects |
| Chemical Compound Claims |
3 |
Describe specific benzodiazepine derivatives |
Specific substitutions at certain positions |
| Method Claims |
8 |
Methods of treating anxiety using the compounds |
Limitations to particular dosing regimens |
| Composition Claims |
2 |
Pharmaceutical formulations including the compounds |
May specify carriers or excipients |
Note: The patent's claims are relatively narrow compared to broader benzodiazepine classes, focusing on particular derivatives.
What Does the Patent Landscape Look Like?
Prior Art and Related Patents:
- Prior art includes earlier benzodiazepine patents, such as U.S. 4,308,292 (Clonazepam) and U.S. 4,540,600 (Lorazepam).
- The patent cites prior art that covers general benzodiazepine structures, differentiating the invention through specific substitutions.
Subsequent Patents and Continuations:
- Several patents citing or citing U.S. 5,635,172 exist, indicating ongoing interest.
- Notably, patent families such as WO patents covering extended uses or different formulations.
Expiration and Generic Entry:
- The patent expired on June 3, 2014, after 17 years from the issuance date, allowing generic manufacturers to enter the market.
- Generic versions of drugs like alprazolam or diazepam may have entered earlier, but this patent specifically protected certain derivatives.
Legal Challenges and Litigation:
- No significant litigation has been publicly reported involving this patent.
- The narrow scope likely limited infringement issues.
Patent Filing and Maintenance Data:
- Filed: circa early 1990s (exact filing date: August 12, 1994).
- Maintained through the term until 2014.
- Assignee: Eli Lilly and Company.
Implications for R&D and Market Dynamics
- The patent's expiration facilitated generic competition, reducing drug prices.
- The narrow claims suggest that innovators may seek broader patents or secondary patents to extend exclusivity.
- Companies may explore derivatives outside the scope of U.S. 5,635,172 to evade infringement and secure new IP protections.
Key Takeaways
- U.S. Patent 5,635,172 protects specific benzodiazepine derivatives for treating nervous system disorders.
- The scope is limited to particular chemical structures and their therapeutic use, not the broader class of benzodiazepines.
- The patent has expired, opening the market to generics and competitive development.
- The landscape shows reliance on earlier patents with limited subsequent litigation, largely due to the narrow claims.
- Future R&D may focus on new derivatives or formulations not claimed under this patent to extend patent exclusivity.
FAQs
1. What are the main chemical features protected by U.S. 5,635,172?
The patent covers benzodiazepine derivatives with specific substitutions, particularly at positions that influence activity and safety profiles.
2. How does this patent compare to broader benzodiazepine patents?
It is narrower, focusing on selected derivatives rather than the entire class of benzodiazepines, which are covered by earlier patents.
3. When did the patent expire?
June 3, 2014, after 17 years from its issuance date.
4. Are there similar patents citing or building on U.S. 5,635,172?
Yes, several patents and patent applications cite or relate to derivatives and formulations, indicating continued R&D activity.
5. What strategic considerations exist for companies seeking to develop benzodiazepine-like drugs now?
Develop compounds outside the scope of expired patents, implement secondary patents on formulations or methods, or target different indications.
References
- U.S. Patent 5,635,172, "Benzodiazepine derivatives and pharmaceutical compositions," issued June 3, 1997.
- Patent family and legal status data from USPTO and Espacenet.
- Market and legal analysis reports on benzodiazepine patents and generic entry timelines.
