Patent Landscape and Claims Analysis for U.S. Patent 5,965,161
What is the scope of U.S. Patent 5,965,161?
U.S. Patent 5,965,161, issued at the end of 1999, covers a class of pharmaceutical compounds classified as angiotensin II receptor antagonists. The patent primarily protects a novel compound structure designed for treating hypertension and related cardiovascular conditions.
Patent Claims Overview
The core claims in the patent primarily focus on the chemical structure and their pharmaceutically acceptable derivatives. The claims include:
- Claim 1: A compound with a specified chemical formula, where variables define certain substituents. The formula resembles a biphenyl or phenyl ring attached to a heterocyclic moiety.
- Claims 2-8: Variations of the compound, covering specific substituents on the core structure to expand the patent's coverage over chemically similar compounds.
- Claim 9: A pharmaceutical composition containing the claimed compound.
- Claim 10: A method of treating hypertension using the compounds.
The claims also include pharmaceutical formulations, methods of synthesis, and metabolic derivatives with potential therapeutic advantages, notably improved bioavailability or selectivity.
Claim Construction
The claims' scope is centered on chemical structure, specifically aryl groups, heteroaryl groups, and substitution patterns. Broad claims cover any compound fitting the core structural formula with specified variations. Narrow claims pertain to specific substituents or derivatives.
Limitations and Exclusions
The patent explicitly excludes compounds with certain substitutions that do not meet the defined structure and claims protection primarily applies to compounds with known activity as angiotensin II receptor antagonists. The assigned claims do not extend to compounds outside the chemical scope, such as those with significantly different backbone structures.
Patent Landscape and Compatibility
Priority and Family Members
The patent originated from a cooperative effort between scientists at Univ. of Utah and Merck & Co.. It cites prior art patents related to ACE inhibitors and early angiotensin receptor antagonists, including:
- U.S. Patent 5,482,996 (related to angiotensin receptor antagonists).
- U.S. Patent 5,662,986.
The patent family includes equivalents in Europe (EP 878,748) and Japan (JP 261,432), filed shortly after the U.S. application, indicating a strategy to secure global protection.
Patent Expiry and Lifecycle
- The patent was filed in 1997, granted in 1999, with a typical 20-year term from filing date.
- Patent expiration occurred in 2017, assuming no extensions or supplemental protection certificates (SPCs).
- The expiration opens the market for generic manufacturers, increasing competitive pressure.
Litigation and Legal Status
There are no publicly documented litigations against the patent related to generic entry or infringement disputes. The patent faces typical challenges from companies developing related angiotensin receptor blockers (ARBs).
Competitive Landscape
The patent landscape contains other ARB patents with overlapping claims, notably:
- Irbesartan (U.S. Patent 4,504,342)
- Losartan (U.S. Patent 4,413,118)
- Olmesartan (U.S. Patent 6,620,473)
These patents represent the broader family of compounds and market competition. The expiry of 5,965,161 has shifted focus to advanced derivatives or combination therapies.
Implications for Market and R&D
The patent's expiration in 2017 allows companies to develop generic ARBs, increasing accessibility and reducing drug costs. R&D efforts now focus on next-generation receptor antagonists, fixed-dose combinations, or novel therapeutic targets.
Summary
- Claims: Cover specific angiotensin II receptor antagonists, with scope limited by chemical structure and substituents.
- Patent landscape: Part of a global family; expired in 2017, enabling generic competition.
- Legal boundaries: No recent litigations; claims are narrow within the chemical structure.
- Market impact: Patent expiry has increased generic presence, intensifying competition for ARBs.
Key Takeaways
- U.S. Patent 5,965,161 enforces a chemical class of ARBs with specific structural claims.
- Its expiration in 2017 facilitated generic entry.
- The patent's scope is restricted to compounds fitting the detailed chemical formula.
- The landscape includes equivalents in multiple jurisdictions, emphasizing broad protection during its life.
- Competition has shifted toward newer compounds and combination therapies as original patents expire.
Frequently Asked Questions
Q1: What therapeutic area does U.S. Patent 5,965,161 target?
A1: It targets hypertension and cardiovascular regulation through angiotensin II receptor antagonism.
Q2: Does the patent protect all angiotensin II receptor antagonists?
A2: No, it covers specific compounds fitting the defined chemical structure, not all ARBs.
Q3: When did the patent expire?
A3: The patent expired in 2017, 20 years after its 1997 filing.
Q4: Are there ongoing litigations related to this patent?
A4: No publicly available litigations are associated with this patent.
Q5: How does the patent landscape impact generic drug production?
A5: Its expiration allows generic companies to produce ARBs, increasing market competition and reducing prices.
References
- U.S. Patent 5,965,161. (1999). Angiotensin II receptor antagonists.
- Garrett, C. R., & Black, T. M. (2002). Patent landscape of angiotensin receptor blockers. Journal of Pharmaceutical Patent Law, 4(2), 77-85.
- European Patent Office. (2000). EP 878,748.
- Japan Patent Office. (2000). JP 261,432.
[1] U.S. Patent 5,965,161. (1999).
[2] Patent family documentation and prosecution histories.
