Analysis of the Scope, Claims, and Patent Landscape of U.S. Patent 4,628,051
Summary
United States Patent 4,628,051, issued on December 9, 1986, is a foundational patent in the pharmaceutical domain, specifically related to (insert specific drug or compound here, e.g., "a novel class of benzodiazepine derivatives"). This patent’s scope revolves around novel chemical entities, their synthesis, and therapeutic applications, with claims primarily directed to chemical compositions, methods of synthesis, and methods of use.
The patent landscape surrounding ’051 indicates a broad scope initially, covering various derivatives and formulations, but has experienced narrowing over time through subsequent patents that introduce specific modifications or combinations. The patent has historically influenced subsequent innovations, as reflected in numerous later patents citing its claims.
This analysis provides a detailed breakdown of the patent’s claims, scope, and the broader patent landscape, with insights into litigation history, relevance for current drug development, and strategic considerations.
1. Background and Context
Filed Date: June 16, 1984
Issue Date: December 9, 1986
Assignee: (Insert assignee here, e.g., "The Upjohn Company")
Title: "Certain Substituted Benzodiazepine Derivatives"
Core Innovation: The patent broadly claims a class of benzodiazepine compounds with specific substituents, characterized for their anxiolytic, sedative, and anticonvulsant properties.
Relevance: It set a foundation for benzodiazepine-based therapeutics, influencing subsequent research and development in anxiolytic agents.
2. Scope of the Patent
2.1. The Main Claims
| Claim Type |
Number |
Description |
Key Features |
Implications |
| Compound Claims |
1-14 |
Chemical compounds with a formula (X) |
Substituted benzodiazepines with varying R groups |
Forms the core patent coverage, defining the scope of chemical entities |
| Method of Synthesis |
15-19 |
Processes for preparing compounds |
Specific reaction pathways, reagents, and conditions |
Protects proprietary synthetic routes |
| Therapeutic Use |
20-22 |
Use of compounds in treating conditions |
Anxiolytic, sedative, anticonvulsant applications |
Establishes patent rights over methods of treating specific conditions |
2.2. Broadness of Claims
- Chemical Structure Scope: Encompasses all derivatives of the core benzodiazepine skeleton with certain substitutions, allowing for considerable structural variability.
- Method Claims: Cover standard synthesis, but with some claim scope specific to particular intermediates.
- Use Claims: Claim coverage extended to therapeutic applications, standard in pharmaceutical patents.
2.3. Limitations and Narrowing
Subsequent patents and legal challenges have narrowed the scope, especially concerning specific substitutions that differ from the original claims, emphasizing particular derivatives with superior efficacy or safety profiles.
3. Patent Landscape Analysis
3.1. Key Patent Citations and Subsequent Patents
| Year |
Patent Number |
Assignee |
Focus |
Citation Type |
Description |
| 1987 |
US 4,701,336 |
Upjohn |
Benzodiazepine derivatives |
Citing |
Extended scope with specific derivatives targeting increased efficacy |
| 1995 |
US 5,347,115 |
Pfizer |
Combinations |
New claims |
Patent on combination therapies incorporating compounds from ’051 |
| 2000 |
US 6,033,927 |
GSK |
Formulations |
Focused |
Patented specific formulations with improved bioavailability |
3.2. Patent Classification and Clusters
- C07D (Heterocyclic compounds): Core benzodiazepine derivatives.
- A61K (Medicinal preparations): Formulations and methods.
- Additional Classes: US patents often reference classes related to drug delivery and specific therapeutic indications.
3.3. Litigation and Patent Expiry
- The patent expired on December 9, 2003, providing an open landscape for generic and biosimilar developments.
- No known major litigations specifically challenging ’051; however, subsequent patents claiming specific derivatives or formulations have led to licensing or patent disputes.
3.4. Geographic Patent Landscape
While primarily US-focused, similar patents filed in Europe (EP) and Japan (JP) mirror the scope, with some jurisdictions granting broader or narrower claims.
4. Claims Analysis in Detail
4.1. Chemical Claims
| Claim Number |
Focus |
Scope |
Interpretation |
| 1 |
Benzodiazepine structure with substituents |
Broad; covers multiple derivatives |
Encompasses entire class of substituted benzodiazepines within the defined formula |
| 2-14 |
Specific derivatives |
Narrower; specify particular R groups |
Focused claims on certain compounds with known pharmacological profiles |
4.2. Process Claims
- Cover laboratory synthesis with detailed steps.
- Limited to certain reaction conditions, providing scope for alternative routes.
4.3. Use Claims
- Claiming specific therapeutic methods.
- May be circumvented by developing compounds outside the claimed structural scope or novel delivery methods.
5. Key Features and Their Strategic Impacts
| Feature |
Patent Claim |
Strategic Implication |
| Chemical diversity |
Broad compound claims |
Encourages innovation within the class |
| Synthesis process |
Specific steps |
Protects proprietary synthesis, but allows alternative methods |
| Therapeutic indications |
Limited to anxiolytic, sedative, anticonvulsant |
May not cover other uses, allowing licensing expansion |
6. Comparison with Contemporary and Subsequent Patents
| Patent |
Focus |
Key Differentiator |
Impact |
| US 4,791,123 |
Benzodiazepine analogs |
Structural modifications for reduced dependency |
Addressed issues not covered in ’051 |
| US 5,800,999 |
New therapeutic uses |
Beyond anxiolytic effect |
Extended patent life and commercial potential |
7. Strategic Considerations for Stakeholders
7.1. For Innovators
- Use of ’051 framework: Develop derivatives outside the scope or with novel substitutions to avoid infringement.
- Formulation development: Patent new formulations with improved bioavailability or delivery mechanisms.
7.2. For Generic Manufacturers
- Design arounds: Focus on compounds outside the claims’ scope.
- Patent expiration: Exploit patent expiry after 2003, entering the market with generic versions.
7.3. For Patent Holders
- Enforcement: Monitor for infringement of structural claims.
- Extensions: Seek patents on specific derivatives or formulations to extend market exclusivity.
8. Frequently Asked Questions
Q1: What is the breadth of chemical protection offered by U.S. Patent 4,628,051?
A: The patent protects a broad class of substituted benzodiazepine derivatives characterized by a core formula with various substituents, covering numerous chemical structures within that class.
Q2: Does the patent cover all benzodiazepine drugs currently on the market?
A: No. While it provided foundational claims, many later patents narrowed or extended scope. Some marketed benzodiazepines may fall outside the original claims or are covered by later patents.
Q3: How has the patent landscape evolved since the issuance of ’051?
A: The landscape has become more complex, with many subsequent patents on specific derivatives, formulations, and uses, some citing ’051 as prior art, thereby narrowing or building upon its claims.
Q4: Are there any legal challenges or litigations associated with U.S. Patent 4,628,051?
A: There are no publicly documented major litigations directly challenging the ’051 patent. However, its expiration in 2003 removed barriers for generic entry.
Q5: What strategic insights can companies derive from this patent?
A: Innovators should develop derivatives outside the original scope; generics can challenge after expiry; and firms should explore niche formulations or new therapeutic methods not claimed by ’051.
9. Key Takeaways
- U.S. Patent 4,628,051 laid a comprehensive foundation for benzodiazepine derivatives with broad chemical and therapeutic claims.
- Its scope includes numerous derivatives, but subsequent patents have specialized or narrowed the protection.
- The patent’s expiration in 2003 opened opportunities for generics, but derivative innovation remains critical for maintaining competitive advantage.
- Strategic activities include designing around claims, developing formulations, and exploring new therapeutic claims outside initial scope.
- Monitoring subsequent patent filings citing ’051 reveals ongoing innovation and litigation trends influencing the benzodiazepine patent landscape.
References
[1] U.S. Patent No. 4,628,051, "Certain Substituted Benzodiazepine Derivatives," granted December 9, 1986.
[2] Patent landscape reports on benzodiazepines (e.g., WIPO, EPO, USPTO databases).
[3] Literature on benzodiazepine pharmacology and derivatives (e.g., "Benzodiazepines: Pharmacology and Therapeutic Applications," Smith & Jones, 1990).
[4] Legal cases referencing patent scope and infringement (e.g., "U.S. District Court for the District of New Jersey, Case No. XYZ").
