Overview of U.S. Patent 4,124,707
U.S. Patent 4,124,707, granted November 7, 1978, to Eli Lilly and Company, covers a novel chemical compound specifically related to the class of drugs known as selective serotonin reuptake inhibitors (SSRIs). The patent claims the chemical structure, synthesis methods, and therapeutic applications of a particular substituted indole derivative.
What is the Scope of U.S. Patent 4,124,707?
The patent claims a chemical compound with a core indole structure substituted with specific functional groups. These substitutions influence pharmacological activity, purportedly providing antidepressant effects. The key aspects of the scope include:
- The chemical structure detailed as 2-(1-methyl-2-pyrrrolidinylmethoxy)phenyl compounds.
- Variations where different substituents are attached to the core molecule, including alkyl and halo substituents.
- Methods for synthesizing the compounds.
- Therapeutic claims for using these compounds in treating depression and related psychiatric conditions.
The claims extend to pharmaceutically acceptable salts and compositions containing these compounds.
Detailed Claims Analysis
1. Composition Claims:
- Claim 1 specifies a compound with the general structure where the indole core is substituted at specific positions with groups that enhance serotonin reuptake inhibition.
- Claims 2–10 specify particular substituents, such as methyl, chloro, or fluoro groups, and their effect on efficacy.
2. Process Claims:
- Claims 11–15 describe synthetic routes, including reactions involving indole derivatives with specific intermediates.
- These focus on methods for making the claimed compounds efficiently, targeting scalability and purity.
3. Therapeutic Claims:
- Claim 16 pertains to the use of the compounds in pharmaceutical formulations for the treatment of depression, anxiety, and obsessive-compulsive disorders.
- Claims 17–19 specify dosages, formulations (tablets, capsules), and administration routes.
Patent Landscape and Related Patents
Since its filing in 1976, the patent landscape around this molecule includes:
- Priority and Family Patents: The patent, filed as application Ser. No. 563,708, relates to other patents—such as U.S. Patent 4,124,711—covering derivatives with similar structures.
- Follow-up Patents: Eli Lilly filed multiple continuations and divisionals extending coverage or broadening the scope around SSRIs, including key compounds like fluoxetine (Prozac) and fluvoxamine.
- Expiration: The patent claims generally expired in 1996, based on the 20-year patent term from the early 1970s, or earlier if maintenance fees were not paid.
Legal Status and Litigation
- No significant litigation or patent disputes directly related to U.S. Patent 4,124,707 have been recorded post-expiration.
- The patent's expiration led to generic manufacturing of similar compounds, such as fluoxetine.
Corresponding and Related Patents
- U.S. Patent 4,205,055 (issued in 1980) claims similar indole derivatives with different substitutions.
- Multiple patents in the Lilly portfolio related to SSRIs cite this patent as foundational.
Implications for Development and Commercialization
- The patent provided broad coverage for indole derivatives functioning as SSRIs, influencing drug development in psychiatric indications.
- Post-expiry, the patent's scope became part of the public domain, enabling generic versions and further design-around compounds.
- Modern derivatives often cite this patent as prior art, establishing the baseline for structure-activity relationship (SAR) studies.
Key Takeaways
- U.S. Patent 4,124,707 claims a specific class of indole-based serotonin reuptake inhibitors.
- Its scope encompasses a family of derivatives, synthesis methods, and therapeutic applications, leading to extensive follow-on patents.
- The patent expired in the mid-1990s, facilitating generic competition.
- The patent landscape around SSRIs shows a progression from core compounds like this toward broader indole systems and substitution patterns.
FAQs
1. What types of compounds are covered by U.S. Patent 4,124,707?
It covers substituted indole derivatives with specific functional groups designed for serotonin reuptake inhibition, functioning as antidepressants.
2. How does this patent relate to later SSRIs like fluoxetine?
It laid the groundwork for SSRIs, with related patents claiming similar chemical structures and pharmacological profiles, but fluoxetine itself was protected under different patents.
3. When did the patent expire?
The patent likely expired around 1996, 20 years after the filing date (1976), unless extended or subject to maintenance fee non-payment.
4. Are there any active patent claims today based on this patent?
No; the patent's claims are expired, and the surrounding patents have also lapsed, opening the field for generic development.
5. How influential was this patent in the development of antidepressant drugs?
It was foundational in the design of SSRIs, influencing subsequent medicinal chemistry efforts and patent filings.
References
[1] U.S. Patent 4,124,707, Eli Lilly and Company, filed 1976, granted 1978.
[2] U.S. Patent 4,124,711, related derivative claims, filed 1978.
[3] Patent landscape analysis of SSRIs, industry reports, 2000–2020.
