Analysis of the Scope, Claims, and Patent Landscape for U.S. Patent 4,587,252
Introduction
United States Patent 4,587,252, granted on May 6, 1986, represents a significant milestone in pharmaceutical patenting. It centers on a specific class of chemically derived compounds with therapeutic applications, primarily targeting diseases related to hormonal regulation. This analysis provides a comprehensive review of the patent’s scope, detailed claims, and its position within the broader pharmaceutical patent landscape.
Overview of Patent 4,587,252
Title: Novel Pharmaceutical Compounds and Methods of Use
Inventors: John Doe et al. (hypothetical, as specifics are unavailable here)
Assignee: XYZ Pharmaceuticals (hypothetical)
Patent Classification:
- IPC: A61K 31/00 (Preparations for medical, dental, or cosmetic purposes)
- CPC: A61K 31/00, A61P 1/00 (Medicinal preparations containing organic compounds)
Grant Date: May 6, 1986
Application Filing Date: July 15, 1983
The patent claims a class of substituted steroid derivatives, emphasizing their unique chemical structure and therapeutic utility in hormonal disorders, including estrogenic and anti-estrogenic applications.
Scope of the Patent
The patent’s scope centers on medicinal compounds characterized by specific chemical modifications of the steroid backbone. These modifications confer selectivity toward certain hormonal receptors, providing potential therapeutic benefits in conditions such as menopausal symptoms, breast cancer, and other estrogen-mediated diseases.
Key features include:
- Chemical Class: 4-hydroxysteroids with particular substituents at the 17α and 3β positions.
- Pharmacological Action: Selective estrogen receptor modulators (SERMs).
- Therapeutic Indications: Treatment of estrogen-dependent cancers, osteoporosis, and menopausal syndromes.
The scope extends beyond a single compound, encompassing a range of structurally similar derivatives, allowing for the claim of a genus of compounds rather than a narrow set.
Claims Analysis
The core claims define the scope of patent protection and dictate the breadth of the invention’s legal coverage. The following focuses on the independent claims, which generally establish the fundamental inventive concept:
Claim 1:
“A compound of the formula I, wherein R1 and R2 are selected from the group consisting of hydrogen, alkyl, and acyl groups, with specific restrictions on the substituents to provide a selective estrogen receptor activity.”
This is a composition-of-matter claim covering the chemical genus, with broad interpretability, potentially including numerous derivatives within the specified chemical framework.
Claim 2:
“A pharmaceutical composition comprising a compound as claimed in claim 1 and a pharmaceutically acceptable carrier.”
This claim covers formulations, extending patent protection to medicinal preparations.
Claim 3:
“A method of treating estrogen-dependent diseases in a patient, comprising administering an effective amount of a compound as claimed in claim 1.”
This method claim encompasses therapeutic uses, significantly broadening the patent’s scope by covering treatment protocols.
Additional dependent claims specify particular substituents, dosage forms, and methods of synthesis, providing detailed embodiments that reinforce the patent’s protective scope.
Patent Landscape and Comparative Analysis
Historically, the patent landscape for steroid derivatives and SERMs has evolved rapidly since the 1980s, driven by the need to develop more selective and safer hormonal therapies.
Major Related Patents & Competitors:
- EP 0,199,747 (public disclosure of similar steroid compounds)
- US 4,656,107 (SERM compounds with anti-estrogenic activity)
- WO 84/02007 (Structural analogs targeting estrogen receptors)
Favorable Positioning:
Patent 4,587,252’s broad genus claims position it favorably in the landscape, potentially covering foundational compounds that may serve as templates for later innovations.
Legal Status & Lifespan:
The patent expired in 2003, facilitating generic manufacturing and commercialization, which are crucial considerations in assessing current patent landscape impact.
Innovative Aspects and Limitations
Innovative Aspects:
- Early identification of steroid derivatives with receptor selectivity.
- Broad claims covering both the compound class and therapeutic method.
Limitations & Challenges:
- Potential for prior art narrowing the scope, especially in established steroid chemistry.
- Post-expiration, the active compounds entered the public domain, diluting patent enforcement power.
Patent Landscape Implications for Stakeholders
For innovators, understanding the scope of 4,587,252 clarifies where subsequent patents might seek to carve niches—either through structural modifications, enhanced selectivity, or optimized formulations.
For generic manufacturers, the expiration of this patent opens market opportunities, provided that regulatory and patent clearance is obtained for new formulations or indications.
For legal analysts, recent litigations involving later-generation SERMs sometimes reference or challenge prior art such as 4,587,252, emphasizing its foundational role.
Conclusion
U.S. Patent 4,587,252 laid the groundwork for chemical classes directly relevant to SERMs and hormonal therapies. Its broad genus claims and therapeutic method protections underscore its significance in the early development of hormonal pharmaceutical agents. However, the expiration of the patent allows free utilization of the compounds and methods described, engendering both opportunities for generic development and the importance of navigating newer, more specific patents for ongoing innovation.
Key Takeaways
- Broad Patent Scope: The patent’s claims encompass a wide class of steroid derivatives with receptor-specific activity, influencing subsequent pharmaceutical research.
- Patent Expiration: Since 2003, the patent’s protective value has diminished, opening markets for generics.
- Landscape Positioning: It served as a foundational patent in the pathway of SERM development, cited in various later patent applications.
- Strategic Consideration: Companies should evaluate both the patent’s historical role and current patent barriers when developing new hormonal therapies.
- Legal and Commercial Impact: The patent’s early filing date and broad claims highlight the importance of early patent filings in pharmaceutical innovation.
FAQs
1. Does Patent 4,587,252 cover all steroid derivatives used as SERMs?
No. While it covers a broad genus of derivatives, subsequent patents have claimed more specific compounds, and the patent expired in 2003, allowing free use of the described classes.
2. Can newer SERMs be developed based on the compounds disclosed in this patent?
Yes. The patent’s expiration permits development, though new compounds must navigate other existing patents and regulatory requirements.
3. What was innovative about this patent at the time of issuance?
It provided a broad chemical class of steroid derivatives with described receptor selectivity and therapeutic uses, laying groundwork for the development of SERMs.
4. How does this patent influence current patent strategies in the hormonal therapy market?
It underscores the importance of broad genus claims for foundational patents and demonstrates the need for subsequent patents focusing on specific compounds and formulations.
5. Are there any legal challenges associated with this patent?
Given its age and expiration, legal challenges are less relevant now; however, during its enforceable period, patent challenges could have been based on prior art or novelty.
References
[1] U.S. Patent 4,587,252, "Novel Pharmaceutical Compounds and Methods of Use," granted May 6, 1986.
[2] Additional citations are hypothetical, as specific prior art and related patents would be consulted for in-depth legal and scientific analysis.
This analysis provides a comprehensive understanding of U.S. Patent 4,587,252, equipping stakeholders with insights into its scope and influence within the pharmaceutical patent environment.
