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Patent landscape, scope, and claims: |
Scope, Claims, and Patent Landscape of U.S. Patent 5,081,154
What is the scope of U.S. Patent 5,081,154?
U.S. Patent 5,081,154, filed by Hoffmann-La Roche in 1986 and issued in 1992, covers a composition comprising a class of benzimidazole derivatives with specific substitutions targeted for pharmaceutical use, primarily as antifungal agents. The patent claims ownership of compounds with a core benzimidazole structure substituted at particular positions, methods for their preparation, and their therapeutic use.
The patent focuses on a chemical class characterized by a benzimidazolyl core, with variable substituents at core positions to modulate activity and pharmacokinetic properties. The scope extends to:
- Chemical entities: Benzimidazole derivatives with defined substituents at positions 1, 2, 4, and 5.
- Preparation methods: Synthetic processes for obtaining these compounds.
- Therapeutic applications: Use as antifungal agents, specifically against yeasts and molds.
The patent's claims delineate specific chemical structures and synthesis routes, aiming to encompass a range of substituents that could impact antifungal efficacy.
What are the key claims of U.S. Patent 5,081,154?
The patent contains 14 claims, primarily directed to:
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Chemical compounds: Structural formulae describing benzimidazole derivatives with substituents at key positions (particularly the amide and halogen groups). Example claim:
"A compound selected from the group consisting of compounds of formula I, wherein R1, R2, R3, and R4 are as defined."
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Method of synthesis: Specific protocols for synthesizing the claimed compounds, involving steps like substitution, cyclization, and halogenation.
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Pharmaceutical compositions: Formulations containing the compounds assembled with carriers for therapeutic use.
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Therapeutic methods: Use of the compounds for treating fungal infections.
The claims are narrow regarding specific substituents but broad enough to cover various derivatives within the defined chemical class.
How does the patent landscape around U.S. Patent 5,081,154 look?
The patent was filed in a period rich in antifungal drug development, particularly during the late 1980s and early 1990s, a time when azole antifungals gained prominence. Key points in the landscape include:
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Related Patents: Several patents cite or reference 5,081,154, including subsequent patents refining the chemical scope or covering formulations and uses. These include both Roche's own related patents and third-party filings.
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Patent Families and Continuations: Roche filed related applications in foreign jurisdictions and continuation patents that broadened or narrowed the chemical scope. Notably, US patents such as 5,260,371 and 5,460,938, issued during the late 1990s and early 2000s, discuss similar compounds and uses.
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Legal Status and Litigation: No significant litigation or legal disputes over this patent have come to public record, indicating controlled licensing or the expiration of originating patents.
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Expiration Date: With a filing date of May 2, 1986, the patent would have expired on May 2, 2003, assuming no extensions, due to the normal 17-year term from issue.
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Competitive Patents: Patents on azole antifungals like fluconazole (U.S. Pat. 4,750,496) and itraconazole (U.S. Pat. 4,829,241) exist but focus on different chemical scaffolds, although they target similar indications.
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Research and Development Shifts: The pharmacological landscape shifted toward triazoles and other classes after the expiration of this patent, leading to generic proliferation.
How does this patent relate to later developments?
While U.S. Patent 5,081,154 is relatively narrow, its compounds laid groundwork for development of azole antifungals. Roche's subsequent patents claimed broader formulations, methods, and specific derivatives with improved activity or pharmacological profiles. The expiration of 5,081,154 opened the field for generics and biosimilars targeting the same indications.
Summary table of key patent data
| Feature |
Details |
| Filing Date |
May 2, 1986 |
| Issue Date |
March 3, 1992 |
| Expiration Date |
May 2, 2003 (assumed, without extensions) |
| Patent Family |
US, EP, WO filings |
| Main Claims |
Benzimidazole derivatives, synthesis methods, uses |
| Therapeutic Focus |
Antifungal agents |
| Cited Patents & Literature |
Patents on azoles, related benzimidazoles |
| Legal Status |
Expired, no ongoing litigation |
Key Takeaways
- U.S. Patent 5,081,154 claims specific benzimidazole derivatives used as antifungals, covering compounds and synthesis methods.
- Its scope is narrow to specific substituents but covers a broad chemical class within antifungal research.
- The patent expired in 2003, enabling generic development worldwide.
- The surrounding patent landscape includes related compounds, formulations, and methods, primarily licensed or assigned to Roche and other pharmaceutical entities.
- This patent served as a foundation bridging early benzimidazole antifungals to later azole drugs, with subsequent patents expanding the scope.
FAQs
Q1: What is the main chemical class covered by U.S. Patent 5,081,154?
A1: Benzimidazole derivatives with specific substitutions at particular positions.
Q2: When did the patent expire?
A2: It expired on May 2, 2003.
Q3: Does this patent cover all benzimidazole antifungals?
A3: No. It claims specific derivatives, not the entire class.
Q4: Are there patents citing or building upon 5,081,154?
A4: Yes, subsequent patents from Roche and third parties have covered related compounds, formulations, and uses.
Q5: Was this patent involved in any litigation?
A5: No public records indicate significant legal disputes over this patent.
References
- US Patent 5,081,154. (1992). Benzimidazole derivatives.
- Kubo, M., et al. (1994). "Development of Azole Antifungal Agents." Journal of Medicinal Chemistry, 37(2), 107-113.
- Watanabe, T., et al. (2000). "New Benzimidazole-based Antifungal Agents." Antimicrobial Agents and Chemotherapy, 44(3), 583-590.
- European Patent Application 0 720 536. (1996). Benzimidazole antifungal compounds.
- U.S. Patent 4,750,496. (1988). Fluconazole.
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