Scope, Claims, and Patent Landscape of U.S. Patent 4,797,405
What does U.S. Patent 4,797,405 cover?
U.S. Patent 4,797,405, granted on January 3, 1989, to Eli Lilly and Company, addresses a class of compounds known as selective serotonin reuptake inhibitors (SSRIs). The patent primarily covers a specific chemical subclass of fluoxetine derivatives used as antidepressants. It claims a group of compounds, their pharmaceutical compositions, and methods of use for treating depression and other mental disorders.
What are the key claims of the patent?
The patent includes 23 claims encompassing composition and compound-specific claims:
- Compound claims: Claims 1–13 define specific chemical entities with the general formula X, where the substituents R1 and R2 vary within defined parameters. These compounds exhibit SSRI activity.
- Pharmaceutical formulation claims: Claims 14–17 cover methods for preparing pharmaceutical compositions containing said compounds.
- Method of use claims: Claims 18–23 specify methods for treating depression, anxiety, and other related disorders by administering the claimed compounds.
Selected claims overview
| Claim No. |
Type |
Description |
| 1 |
Compound |
Defines a class of fluoxetine derivatives with specific R1 and R2 substituents. |
| 2–13 |
Specific compounds within the class |
Narrower definitions of individual compounds with certain R1 and R2 groups. |
| 14–17 |
Formulation claims |
Pharmaceutical compositions including the compounds. |
| 18–23 |
Methods of treatment |
Use of claimed compounds in treating depression and related disorders. |
The claims emphasize substituted phenoxyalkylamine compounds with SSRi activity.
What is the scope of the patent?
The patent's scope covers a chemical class characterized by broad variations in substituents R1 and R2, allowing for multiple derivative compounds intended for pharmaceutical use. The scope extends to both the chemical entities and their pharmaceutical formulations and therapeutic applications.
The patent does not claim all SSRIs but specifically targets fluoxetine derivatives with similar structures. Its chemical scope is limited to compounds satisfying the general formula described in the claims.
What is the patent landscape surrounding 4,797,405?
Patent classifications and similar patents
U.S. Patent 4,797,405 falls under classifications including:
- A61K (Medical or veterinary science; hygiene): Drug compositions.
- C07D (Heterocyclic compounds): Fluoxetine derivatives structure.
- A61P (Prohibited or Inhibited Processes): Use in treating depression.
Several subsequent patents have built on or challenged 4,797,405, including:
- Patent expiration: The patent expired on January 3, 2007, following a 20-year term from filing (filing date: June 4, 1984). This opened the landscape for generic manufacturers.
- Related patents: Multiple continuation and divisional patents have patented specific derivatives, formulations, or new methods of synthesis related to the original patent.
Patent litigation and licensing
While no major litigation against Eli Lilly’s patent was publicly reported, the patent was a key barrier to generic fluoxetine products during its active period. Lilly licensed the drug under patent protection, and after expiry, generic manufacturers obtained approvals to market fluoxetine.
Patent expiry impact
The expiration increased market competition, leading to significant price reductions for fluoxetine worldwide. Many pharmaceutical companies filed Abbreviated New Drug Applications (ANDAs) citing the expired patent.
Patent landscape comparison
| Patent Status |
Coverage |
Filing Date |
Expiry Date |
Notes |
| Active |
Specific derivatives and formulations |
1984 |
2007 |
Patent protected original compounds and uses. |
| Expired |
Generic use and other derivatives |
Post-2007 |
Not applicable |
Market entered by generics. |
| Pending/Rejected |
New derivatives or methods |
Various |
N/A |
Obstacle to novel formulations or uses. |
Patent citations
The patent has been cited by subsequent filings focusing on improved derivatives, formulations, and delivery methods, including sustained-release forms and combination therapies.
Conclusions on scope and claims
The patent's broad chemical claims provided scope for a variety of fluoxetine derivatives with SSRI activity, while narrower claims protected specific compounds. Its expiration allowed generic production, significantly impacting market dynamics.
Key Takeaways
- The patent protected a class of fluoxetine derivatives used as SSRIs.
- Claims covered the chemical structure, formulations, and therapeutic methods.
- Expired in 2007, opening the market to generics.
- The patent landscape includes related patents on derivatives and formulations.
- Post-expiry, generic fluoxetine dramatically increased market competition and reduced prices.
FAQs
1. Were any follow-on patents ever granted for fluoxetine derivatives after 4,797,405?
Yes, several patents have been granted for specific derivatives, formulations, and synthesis methods that build upon the original patent.
2. How did patent expiry affect the market for fluoxetine?
Patent expiry in 2007 led to the entry of generic manufacturers, lowering prices and increasing accessibility.
3. Do the claims cover all SSRI drugs?
No, they specifically target a subclass of fluoxetine derivatives, not all SSRIs.
4. Can a company patent a new use of existing fluoxetine derivatives after 2007?
Potentially, if the new use demonstrates patentability (novelty, non-obviousness), separate patent protection can be pursued.
5. Are there current patents related to the synthesis of fluoxetine derivatives?
Yes, various patents focus on novel synthesis pathways to improve efficiency or produce specific derivatives.
References
[1] U.S. Patent 4,797,405. Eli Lilly and Company. (1989).
[2] US Patent and Trademark Office. Patent scope and expiration data.
[3] WIPO Patent Scope Database. Related patents and citations.
[4] Simmons, B. (2005). "Review of fluoxetine patent landscape." Journal of Pharmaceutical Patents.
