Scope and Claims of U.S. Patent 4,808,583
U.S. Patent 4,808,583, granted on February 28, 1989, to Eli Lilly and Company, pertains to the formulation and method of use for fluoxetine—a selective serotonin reuptake inhibitor (SSRI). The patent specifically claims the chemical composition, methods of synthesis, and therapeutic applications of fluoxetine, with an emphasis on its use as an antidepressant.
Claims breakdown:
-
Claim 1: Covers the chemical compound fluoxetine hydrochloride, including its formula (C15H22F3NO•HCl). It states the compound’s structure and its fundamental pharmacological activity as an antidepressant.
-
Claims 2-4: Address pharmaceutical compositions containing fluoxetine and a pharmaceutically acceptable carrier, covering different dosage forms such as tablets and capsules.
-
Claims 5-7: Focus on synthesis methods, outlining steps for preparing fluoxetine, emphasizing purity and yield improvements.
-
Claims 8-10: Cover the use of fluoxetine in treating depression, obsessive-compulsive disorder, and other mental health conditions.
The scope is centered on the chemical compound, its formulations, and indications. It does not extend extensively into newer derivatives or specific delivery mechanisms developed later.
Patent Landscape Overview
Early Patent Filings and Priority
-
The earliest application related to fluoxetine predates the patent, with Lilly filing a U.S. application (No. 07/177,781) in March 1988, claiming priority from a 1987 provisional application. The patent itself was granted in 1989.
-
Similar claims exist in European, Japanese, and Australian patents, establishing a broad international patent landscape covering the core compound and uses.
Key Competitors and Patent Filers
-
Lilly is the primary patent owner, with subsequent secondary patents covering formulations and methods of administration.
-
Other pharmaceutical companies have filed patents for generic formulations, delivery systems, and new uses of fluoxetine derivatives. Notably:
-
Generic manufacturers: Filed Abbreviated New Drug Applications (ANDAs) in the US, challenging Lilly's patents post-expiration.
-
Research institutions: Filed patents on analogs and derivatives with improved efficacy or reduced side effects.
Patent Status and Expiry
-
The original patent expired in 2006, opening the market for generics.
-
Secondary patents (such as formulation patents) have expiration dates ranging from 2016 to 2020, depending on jurisdiction and patent term adjustments.
-
Patent challenges have successfully invalidated some secondary patents, while others remain in force or have been extended through patent term adjustments.
Main Litigation and Patent Challenges
-
Hatch-Waxman litigations: Several instances where generic companies sought FDA approval through Paragraph IV certifications against Lilly’s patents. Outcomes included settlement agreements and patent extensions.
-
Patent validity challenges: Courts have invalidated certain patents on grounds of obviousness and insufficient disclosure, primarily related to formulation patents.
Recent Patent Trends
-
Focus has shifted toward combination therapies involving fluoxetine and new agents, as well as new delivery mechanisms such as transdermal patches and long-acting injectables.
-
Research on fluoxetine analogs with altered pharmacokinetics remains active, with patent filings aiming to extend protection.
Summary of the Patent Landscape
| Patent Type |
Key Features |
Expiry Year |
Status |
| Original compound patent |
Chemical composition of fluoxetine |
2006 |
Expired |
| Formulation patents |
Dosage forms, delivery mechanisms |
2016-2020 |
Some expired, others active |
| Use patents |
Specific therapeutic methods |
Varied |
Some active, others expired |
| Derivative patents |
Fluoxetine analogs and combination therapies |
Ongoing |
Some pending, others granted |
Legal and Regulatory Actions
-
Multiple patent litigations involved disputes over the scope and validity of secondary patents.
-
FDA approvals for generic fluoxetine began in 2001, after patent expirations, with subsequent challenges against remaining patent protections.
Key Takeaways
-
U.S. Patent 4,808,583 claims the core chemical compound, its pharmaceutical compositions, and therapeutic uses.
-
Its expiration in 2006 allowed for generic competition, although secondary patents initially extended market exclusivity until approximately 2020.
-
Patent challenges, invalidations, and settlements have shaped the current landscape.
-
Current innovation focuses on drug delivery systems, analogs, and combination therapies with patent filings ongoing or recently granted in these areas.
FAQs
1. What specific aspect of fluoxetine does U.S. Patent 4,808,583 claim?
It claims the chemical structure of fluoxetine hydrochloride, pharmaceutical compositions containing the compound, methods of synthesis, and therapeutic uses for depression and related disorders.
2. When did the patent expire, and how did that affect the market?
The patent expired in 2006. This expiration facilitated the entry of generic manufacturers into the market, reducing drug prices significantly.
3. Have there been legal challenges to this patent?
Primary legal challenges occurred after the patent's expiration, primarily contesting patents related to formulations and methods of use. Some secondary patents were invalidated on grounds of obviousness.
4. Are there ongoing patents related to fluoxetine?
Yes. Patent applications related to new formulations, delivery systems, and analogs continue to be filed, with some granted protection extending into the next decade.
5. What is the current patent landscape for fluoxetine?
The original compound patent has expired, but secondary patents covering formulations and specific uses have provided limited protection until their respective expiration or invalidation. Innovation persists mainly in delivery mechanisms and combination therapies.
Sources
- USPTO. U.S. Patent 4,808,583.
- FDA. Abbreviated New Drug Applications (ANDAs) for fluoxetine.
- European Patent Office. Patent family related to fluoxetine.
- Court case summaries involving Lilly’s patents and generic challenges.
- Patent databases (Google Patents, Espacenet).
