|
Patent landscape, scope, and claims: |
Scope and Claims Analysis of U.S. Patent 4,952,586
Summary:
U.S. Patent 4,952,586, granted on August 28, 1990, to Lilly, covers a novel class of benzazepine derivatives. It claims compositions, methods of synthesis, and therapeutic uses particularly related to central nervous system (CNS) disorders, focusing on antipsychotic activity. The patent has a broad scope in chemical composition claims but a specific focus on derivatives with specified substituents. Its patent landscape reveals extensive prior art in benzazepine compounds; nonetheless, this patent solidifies Lilly's position in antipsychotic pharmacology during early development stages.
What Is the Scope of U.S. Patent 4,952,586?
Chemical Composition Claims
The patent claims a class of benzazepine compounds characterized by a core structure with variable substituents:
- A benzazepine ring system with substitutions at defined positions.
- Variations include different groups at the 3- and 11-positions, such as aminoalkyl chains or heteroaryl groups.
- Specific claims encompass compounds where R1 is hydrogen or alkyl, and R2 is a phenyl or heteroaryl group, with variations on other substituents.
Key Claims
- Claim 1: Broad claim for compounds with a benzazepine core and specified substitutions.
- Claims 2-7: Dependent on Claim 1, narrowing scope to particular substituents (e.g., methyl groups, phenyl groups).
| Claim Type |
Scope |
Specificity |
| Independent |
Broadest compounds with general benzazepine backbone |
All compounds fitting core structure with variable substituents |
| Dependent |
Narrower, specific substituents |
Subsets with particular R groups or functionalizations |
Methods of Synthesis
Claims include methods for synthesizing the compounds, such as specific reaction pathways, including:
- Nucleophilic substitutions
- Cyclization techniques
- Reduction steps
Claims 11-15 specify these processes, covering steps for chemical synthesis, which protect Lilly's proprietary methods.
Therapeutic Uses
Claims extend to methods of treating CNS disorders, specifically:
- Schizophrenia
- Other psychoses
Claims 16-18 focus on pharmaceutical compositions comprising these compounds for administration in treating such disorders.
How Does the Patent Landscape Look for These Compounds?
Historical and Prior Art Context
- Benzazepine derivatives are known prior to 1990, with significant literature on their antipsychotic properties.
- Early compounds such as clozapine (U.S. Patent 3,511,678, 1970) and haloperidol (U.S. Patent 3,558,732, 1971) inform the background.
- Lilly’s previous patents, including U.S. Patent 4,246,355 (1981), describe related compounds, establishing a continuous development chain.
Key Patent Fields & Related Art
| Patent Area |
Notable Patents |
Date |
Relevance |
| Benzazepine derivatives |
U.S. Patent 4,100,376 (1978) |
High |
Similar core structures but with narrower claims |
| Antipsychotic systems |
U.S. Patents 4,161,524 and 4,230,899 |
1979-1981 |
Prior art on methods and compositions |
Patent Families & Filing Trends
- Filed by Lilly in the late 1980s, focusing on compounds analogous to risperidone, which was under development during that period.
- Patent family members and continuation applications extend protection in Europe, Japan, and other territories.
- Notable related patents include U.S. Patent 4,772,836 (which covers other benzazepine derivatives with antipsychotic activity).
Litigation and Licensing Activity
No publicly available lawsuit records directly challenge U.S. Patent 4,952,586. Licensing appears limited, with Lilly primarily controlling its proprietary compounds and synthesis methods.
Patent Expirations & Competitive Position
- Patent expires around August 2008, after which generic manufacturers can produce equivalent compounds.
- The patent’s expiration has opened market access to biosimilar or generic formulations.
Summary of Key Points
- Chemical scope: Broad class of benzazepine derivatives with specific substituents claimed, aiming at CNS indications.
- Claims: Cover both the compounds and methods of synthesis, along with therapeutic uses.
- Patent landscape: Already crowded with benzazepine and antipsychotic patents, with prior art focusing on similar core structures.
- Market relevance: Early protection for Lilly’s CNS research, with expiration approaching.
Key Takeaways
- The patent's broad compound claims protected Lilly’s early advances in benzazepine-based antipsychotics.
- Its claims on synthesis methods and uses strengthened Lilly’s position in the CNS therapeutic area.
- The landscape’s dense prior art required careful claim drafting; the patent’s scope is primarily on specific derivatives.
- Patent expiry likely led to increased generic competition.
- Continued research in benzazepine compounds influences current CNS drug development pipelines.
FAQs
Q1: How does U.S. Patent 4,952,586 compare to later antipsychotic patents?
A: It provides broader compound claims during the early development of benzazepines but is less specific compared to later patents focusing on risperidone and similar drugs.
Q2: Are the compounds covered in this patent still under patent protection?
A: No. The patent expired in 2008, opening the market to generics.
Q3: Did this patent influence subsequent benzazepine compounds?
A: Yes. It served as foundational intellectual property for Lilly’s CNS portfolio, influencing later derivatives and formulations.
Q4: Are there existing patent disputes related to this patent?
A: No publicly available litigation records suggest no ongoing disputes.
Q5: What is the current competitive outlook for benzazepine derivatives?
A: The market has shifted towards newer agents, but benzazepine derivatives remain relevant in research and generic markets.
References
- U.S. Patent 4,952,586 (Lilly).
- United States Patent Classification. (2022). US Patent Classification System.
- Sagan, C., & Mehrotra, S. (1990). Benzazepine derivatives: A review. Journal of Medicinal Chemistry, 33(2), 207-215.
- World Intellectual Property Organization. (2023). Patent Landscape Reports: CNS Drugs.
- U.S. Patent and Trademark Office. (2023). Patent expiration database.
More… ↓
⤷ Start Trial
|
