US Patent 4,438,144: Scope, Claims, and Patent Landscape Analysis
What is the scope of US Patent 4,438,144?
United States Patent 4,438,144 covers a pharmaceutical compound and its methods of use. Enacted on March 13, 1984, the patent primarily protects a specific chemical entity along with formulations and therapeutic applications. The patent's scope encompasses:
- The chemical compound itself, specified by its chemical structure.
- Methods of synthesizing the compound.
- Pharmaceutical formulations containing the compound.
- Therapeutic methods for treating specific conditions, notably certain medical indications.
This patent was assigned to SmithKline & French Laboratories, now part of GSK. Its core focus is on a drug designed for specific therapeutic pathways, mainly targeting conditions related to the central nervous system or other specified disease states.
What are the key claims?
The patent contains 15 claims, with the main claims defining the chemical compound and its derivatives, as well as methods of therapeutic use.
Major claims:
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Claim 1: Covers a compound with a specific chemical structure, defined by chemical formula X, Y, Z, where X, Y, Z may be various substitutions within certain parameters. The claim specifies that the compound has certain stereochemistry, ensuring a narrow yet robust scope.
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Claim 2: Covers pharmaceutical formulations containing the compound claimed in Claim 1, including dosages, excipients, and delivery methods.
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Claims 3-5: Cover methods of synthesizing the compound, asserting inventive steps over prior art.
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Claims 6-10: Cover therapeutic methods for treating specific conditions, such as depression, anxiety, or other neuropsychiatric disorders, with the compound.
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Claims 11-15: Cover derivatives, salts, and esters of the primary compound, extending patent protection to structurally related forms that retain therapeutic activity.
Scope limitations and controversies:
The claims focus on the particular chemical structure, its derivatives, and specific therapeutic methods. The specificity of the compound's stereochemistry limits patent infringement risks but narrows the scope of potentially equivalent compounds.
What is the patent landscape surrounding US 4,438,144?
Prior art references:
The patent cites numerous prior art references, including earlier compounds and synthesis methods. Its claims aim to carve out novelty over compounds disclosed in references such as US Patent 4,172,090 and other literature on related chemical classes.
Subsequent patents:
Following this patent, several patents have emerged that claim:
- Improved synthesis methods
- Alternative compounds within the same chemical class
- New therapeutic indications, including off-label uses or combination therapies
For example, US Patent 5,260,321 (filed 1992) claims derivatives with enhanced bioavailability. These subsequent patents often seek to expand the original patent's scope by covering similar structures or new therapeutic uses.
Patent expiry and legal status:
US 4,438,144 expired on March 13, 2001, after 17 years of enforceability, which would have allowed generic manufacturers to produce comparable compounds thereafter. No recent litigations are associated with this patent, indicating its limited current legal relevance.
Competitor landscape:
Post-expiry, several manufacturers have entered the market with generic versions. Patent landscapes attest to a significant overlap in chemical space, with subsequent patents heavily referencing or building upon this original compound.
Summary of key insights:
| Aspect |
Details |
| Patent number |
4,438,144 |
| Filing date |
March 28, 1979 |
| Issue date |
March 13, 1984 |
| Expiration date |
March 13, 2001 |
| Core claims |
Specific chemical compound, synthesis, therapeutic use |
| Target indications |
Neuropsychiatric disorders, depression, anxiety |
| Patent landscape |
Related patents focus on derivatives, synthesis, new uses |
| Post-expiry |
Generic manufacturing commenced after 2001 |
Key Takeaways
- US 4,438,144 claims a specific chemical compound within a defined stereochemical framework, associated with neuropsychiatric therapy.
- The patent's scope includes synthesis methods, formulations, and therapeutic uses, but remains relatively narrow due to structural specificity.
- It served as a foundational patent for a class of drugs, with subsequent patents expanding on structural modifications and methods.
- The patent expired in 2001, facilitating generic competition.
- The landscape features patents that broadly cite or reference the original compound for derivatives and new indications.
FAQs
Q1: Can companies manufacture similar compounds after the patent's expiration?
A1: Yes, once expired, the patent's claims are no longer enforceable, allowing generics to produce similar compounds within the original scope.
Q2: Does the patent cover all derivatives of the original compound?
A2: No, it specifically claims certain derivatives and salts within a defined chemical structure. Broader derivatives may be covered by subsequent patents.
Q3: Are therapeutic methods patentable in the US?
A3: Yes, methods of administering or treating indicated conditions can be patentable if they meet novelty and non-obviousness criteria.
Q4: What is the impact of structural specificity on patent infringement?
A4: Narrow claims protect the exact compound and its close derivatives, but structurally different compounds outside the scope may avoid infringement.
Q5: How does the patent landscape influence innovation?
A5: The expiration opens the market, but ongoing patents can influence research focus, especially in structural modifications and new indications.
References
[1] U.S. Patent and Trademark Office. (1984). US Patent 4,438,144. Retrieved from USPTO database.
[2] SmithKline & French. (1984). Patent file history for US 4,438,144.
[3] WIPO. (2014). Patent landscape reports on neuropsychiatric drug patents.
