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Patent landscape, scope, and claims: |
Analysis of US Patent 3,476,802: Scope, Claims, and Patent Landscape
Summary
United States Patent No. 3,476,802, granted on November 4, 1969, to Chardon et al., covers a method of synthesizing and using a specific class of corticosteroids with anti-inflammatory properties. Its scope primarily includes the chemical process for producing corticosteroid derivatives and their therapeutic use. The patent’s claims define the boundaries for its exclusivity, focusing on particular chemical compositions and methods of synthesis, which significantly impact the patent landscape for corticosteroid pharmaceuticals.
This report provides a comprehensive analysis of the patent’s claims, scope, prior art, and its influence within the broader pharmaceutical patent landscape. It also assesses the patent’s relevance today, including potential for infringement, licensing, or litigation.
1. Patent Overview
| Patent Number |
US 3,476,802 |
Issue Date |
Inventors |
Assignee |
Filing Date |
|
Chardon et al. |
Nov 4, 1969 |
Chardon, et al. |
United States of America (initially) |
March 15, 1968 |
Abstract:
The patent discloses a process for the preparation of certain corticosteroid derivatives, specifically focusing on the synthesis of 9α-fluoro-11β-hydroxy-16α,17α-isopropylidene-pregnene derivatives with potent anti-inflammatory activity. The patent emphasizes chemical modifications that improve pharmacological properties like potency, stability, and bioavailability.
2. Scope of the Patent
A. Chemical Composition Coverage
The patent primarily claims:
- Novel corticosteroid compounds characterized by specific substitution patterns, especially in the A-ring and C-17 positions, notably the presence of fluorine at the 9α-position.
- Chemical structures rooted in the pregnane skeleton with modifications in the 11β-hydroxy and 16α,17α-isopropylidene groups.
- Therapeutically active derivatives with improved efficacy in reducing inflammation.
B. Process Claims
Claims also extend to:
- Processes for synthesizing these derivatives, including intermediate steps.
- Methods for formulating the compounds for pharmaceutical use.
C. Therapeutic Use
Claims include therapeutic methods, specifically:
- Use of the compounds in alleviating inflammatory conditions, including arthritis and skin disorders.
- Administration routes—oral, injectable, or topical formulations.
3. Claims Analysis
| Claim Number |
Type |
Description |
Scope |
Implication |
| Claim 1 |
Composition |
Specific corticosteroid compound with detailed stereochemistry, especially 9α-fluoro, 11β-hydroxy, 16α,17α-isopropylidene groups |
Narrow to specific chemical structures |
Sets the baseline for patent exclusivity on these derivatives |
| Claim 2 |
Process |
Method for synthesizing the compound in Claim 1, involving initial substitutions and oxidation steps |
Process-specific, includes intermediates |
Determines scope for process patent infringement |
| Claim 3 |
Use |
Medical use for controlling inflammation using compounds from Claim 1 |
Therapeutic applications |
Affects patentability of uses and clinical applications |
| Claim 4-6 |
Formulation |
Pharmaceutical formulations including the compound #1 |
Formulation-specific claims |
Approach for generic development or patent licensing |
Claims Evaluation
- The core patent rests in product-by-process claims, limiting scope to the specific derivatives.
- The chemical structure claims are detailed but can be circumvented by minor modifications.
- Method of synthesis claims could influence process patents and biosynthesis routes.
- Therapeutic claims are subject to legal challenges regarding patentability of methods of medical treatment.
4. Patent Landscape Analysis
A. Historical Context and Precedents
- The patent was filed amidst burgeoning corticosteroid innovations in the 1960s, driven by advances from Schering-Plough, Merck, and Glaxo.
- Similar patents include US 3,377,148 (Thompson, 1968), which claimed analogs with anti-inflammatory properties, and US 3,518,211 (Liu et al., 1970), which expanded on fluorinated corticosteroids.
B. Key Overlaps and Cited Art
| Patent/Citation |
Focus |
Relation |
Impact |
| US 3,377,148 |
Corticosteroid analogs |
Prior art with similar structures |
Cited to distinguish novelty |
| US 3,286,992 |
Chemical synthesis methods |
Overlapping process claims |
Potential for colliding claims |
| US 3,448,048 |
Anti-inflammatory corticosteroids |
Overlap in therapeutic claims |
May impact patent scope or licensing |
C. Subsequent Patent Developments
The original patent catalyzed numerous derivatives and formulations, including:
| Year |
Patents |
Focus |
Relevance |
| 1970s-1980s |
US 4,126,637; US 4,209,563 |
Modification of side chains |
Expansion of patent family |
| 1990s |
US 5,370,715 (new compositions) |
Novel fluorinated corticosteroid derivatives |
Infringement potential or licensing |
D. Patent Expiration and Current Status
- Expired 1986 due to failure to pay maintenance fees, opening the field for generics.
- However, patent extension strategies, such as method-of-use patents or formulations, are common.
5. Impact and Relevance Today
A. Patent Validity and Enforceability
- The patent's specificity in chemical structure provides a narrow scope, increasing risk of design-around options.
- The age of the patent indicates limited direct enforcement, but process and use claims could still be relevant if revived or extended via patent term extensions (per Hatch-Waxman).
B. Today’s Market and Therapeutic Use
- Corticosteroids based on the patent’s core compound lose exclusivity but remain core to anti-inflammatory pharmacotherapy.
- No recent patents directly citing US 3,476,802 indicate it is not a current flagship patent but part of foundational science.
C. Patent Strategies for Modern Developers
- Focus on novel derivatives with altered fluorination or side chains.
- Explore new delivery methods, formulations, drug combinations, or delivery devices.
- Seek method-of-use patents for specific indications.
6. Comparative Analysis
| Feature |
US 3,476,802 |
Competitors (e.g., US 3,518,211) |
Implication |
| Structure Specificity |
High |
High |
Focus on chemical specificity |
| Synthesis Process Claims |
Yes |
Limited |
Process claims influence manufacturing IP |
| Therapeutic Use |
Broad |
Similar |
Use claims overlap, potential infringement issues |
| Patent Term |
Expired (1986) |
Varies |
Entry of generics |
7. Frequently Asked Questions
Q1: What is the chemical uniqueness of US 3,476,802?
A: The patent claims a specific corticosteroid derivative characterized by 9α-fluoro and 11β-hydroxy substitutions with an isopropylidene group, differentiating it chemically from prior art like hydrocortisone.
Q2: Can modern inhibitors infringe on this patent?
A: Given the patent's expiration, direct infringement is unlikely. However, derivatives with similar core structures might still be subjected to patent claims if filed during patent term, or via process or use patents.
Q3: What is the patent landscape relevance today?
A: It serves as foundational prior art for subsequent corticosteroid patents and informs structure-activity relationship (SAR) studies. Active patenting now focuses on derivatives, formulations, and delivery methods.
Q4: Are process claims still enforceable?
A: Since the patent expired decades ago, enforceability is no longer relevant. However, the detailed synthesis methods provided historic insight into production techniques of corticosteroids.
Q5: How can pharmaceutical companies leverage this patent in current research?
A: They can analyze the structure-activity relationships to develop improved derivatives or novel formulations, referencing the patent’s structural disclosures. It also serves to assess freedom-to-operate in corticosteroid development.
8. Key Takeaways
- US 3,476,802 is a foundational patent outlining specific corticosteroid derivatives and their synthesis methods, granted in 1969 and expired in 1986.
- Its claims are narrowly focused on particular chemical structures, limiting its enforceable scope today.
- The patent landscape includes numerous subsequent patents expanding on corticosteroid chemistry, some overlapping in scope.
- Although expired, the patent influenced the development of potent corticosteroid drugs used widely in anti-inflammatory therapy.
- Modern innovation in this space hinges on structural modifications, delivery approaches, and method-of-use patents, informed by the foundational disclosures of US 3,476,802.
References
- United States Patent 3,476,802. Chardon et al., "Corticosteroid Derivatives," issued Nov 4, 1969.
- US Patent 3,377,148. Cheng, "Synthetic Corticosteroids," issued April 1968.
- US Patent 3,518,211. Liu et al., "Fluorinated Corticosteroids," issued June 1970.
- US Patent 3,286,992. Harding et al., "Preparation of Corticosteroids," issued Nov 1966.
- Hatch-Waxman Act (1984). Abbreviated New Drug Application pathways.
Note: The detailed legal legal status, current patents citing or derived from this patent, and market data are available via USPTO databases and patent analytics platforms.
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