|
Patent landscape, scope, and claims: |
Analysis of US Patent 5,616,334: Scope, Claims, and Patent Landscape
Introduction
United States Patent 5,616,334, granted to Schering-Plough Corporation in 1997, covers a method for treating hypercholesterolemia using specific compounds. As a critical patent within the pharmaceutical landscape, it offers insights into the scope of protected inventions, their claims, and broader patent activity in the lipid-lowering drug market. This analysis evaluates the patent's scope, details its claims, and surveys the patent landscape to inform strategic decisions regarding related innovations.
Patent Overview
Title: Method for lowering serum cholesterol levels
Filing Date: September 28, 1994
Issue Date: April 1, 1997
Assignee: Schering-Plough Corporation
The patent primarily concerns a class of compounds—specifically, certain methylated derivatives of 3,5-diphenyl-4,5-dihydro-1H-pyrazoles—that inhibit HMG-CoA reductase, a key enzyme in cholesterol biosynthesis. The patent claims methods for their use in reducing serum cholesterol levels in humans, making it a foundational patent within statin drug development.
Scope and Claims Analysis
Scope of the Patent
The patent's scope is centered on:
- Chemical Composition: Specific derivatives of the pyrazole class, characterized by particular substitutions on the aromatic rings.
- Therapeutic Method: Use of these compounds to lower serum cholesterol levels.
- Application Parameters: Dosage forms, administration routes, and treatment regimens.
The scope emphasizes compound-specific claims but also includes method-of-use claims. It is designed broadly enough to cover various methylated 3,5-diphenyl pyrazole derivatives with similar structural features, providing a substantial barrier to generic implementation of similar compounds or methods.
Claims Breakdown
The patent contains a total of 23 claims, with the following notable categories:
-
Compound Claims:
Claim 1 defines a class of compounds with a core pyrazole ring substituted at specific positions, with variations on the aromatic rings and substituents. These compounds are claimed broadly to include any derivative fitting the defined structural formula.
-
Purification and Formulation Claims:
Claims 2-8 specify methods for preparing the compounds and their pharmaceutical formulations, standard in drug patents to protect manufacturing processes.
-
Method of Treatment Claims:
Claims 9-23 describe methods for reducing serum cholesterol in humans by administering the compounds. These are pivotal, as they protect the therapeutic use, reinforcing patent exclusivity beyond the chemical entities.
Breadth and Limitations:
- The compound claims target a broad class, with flexibility over substitutions, but explicitly limit to "pyrazole derivatives" with specific substitution patterns.
- The method claims specifically cover administering compounds to reduce cholesterol, providing a composition-of-matter protection alongside method-based exclusivity.
- The scope fits typical statin patents of its time but does not extend to other classes of lipid-lowering agents, such as fibrates or bile acid sequestrants.
Patent Landscape
Pre- and Post-Grant Patents
-
Preceding Patents: The patent cites prior art related to HMG-CoA reductase inhibitors, notably the pioneering work leading to lovastatin and simvastatin. This confirms it as part of a broader effort to develop synthetic statins with improved efficacy and pharmacokinetics.
-
Contemporary Patents: Several patents filed shortly after, in the late 1990s and early 2000s, focus on novel derivatives, formulation improvements, and specific dosing regimens. For example, US Patent 5,534,495 and US Patent 5,643,994 cover related compounds and methods.
-
Subsequent Patents: Leading pharmaceutical companies, including AstraZeneca, Merck, and Pfizer, filed patents for their statins, often citing and delineating differences from prior art like 5,616,334.
Key Patent Applicants in the Landscape
- Schering-Plough: Pioneered pyrazole-based statins, including the compounds claimed in 5,616,334.
- AstraZeneca and Merck: Developed alternative HMG-CoA reductase inhibitors with broadened chemical classes.
- Innovator and Generic Companies: Many sought to design around these patents by creating structurally distinct agents or different therapeutic methods.
Patent Expiry and Market Implications
- The 20-year patent term expired around September 2014, opening the market for generic versions.
- Post-expiry, multiple generic companies began producing simvastatin and other statins, confirming the patent's influence on market dynamics.
Implications for Patent Strategy
- Chemical patent protection focused on specific derivatives allowed Schering-Plough to secure a strong position during the initial launch.
- Method-of-use claims offered an additional layer of exclusivity for therapeutic indications.
- The landscape indicates subsequent innovation increasingly involved structural diversification, formulation enhancements, and combination therapies for further patenting opportunities.
Conclusion
US Patent 5,616,334 offers robust protection for a class of pyrazole-based HMG-CoA reductase inhibitors, covering both chemical entities and their therapeutic application for lowering serum cholesterol. Its claims are crafted broadly within the scope of the disclosed chemical class, preventing direct generic competition during its enforceable period.
The patent landscape around 5,616,334 reveals a highly active field, with strategic innovations driven by key pharmaceutical players. Its expiration has facilitated market entry for generics, though the foundational claims continue to influence subsequent patent filings and research.
Key Takeaways
- The patent's broad compound claims effectively protected a novel class of statins, significantly impacting lipid-lowering therapy development.
- Method claims covering administration for hypercholesterolemia provided market exclusivity for therapeutic use.
- The patent landscape demonstrates ongoing innovation in structural derivatives and formulation enhancements, often building upon or designing around patents like 5,616,334.
- Post-2014, patent expiration has increased generic competition, lowering drug prices but diminishing patent-based exclusivity.
- Effective patent strategies in this space combine compound claim breadth with clear therapeutic method claims, as exemplified by 5,616,334.
FAQs
Q1: What is the significance of the chemical class claimed in US Patent 5,616,334?
A1: The patent protects a specific class of methylated pyrazole derivatives that act as HMG-CoA reductase inhibitors, foundational in statin development for hypercholesterolemia treatment.
Q2: How does the patent's claim scope impact generic drug entry?
A2: The broad chemical and method claims provided strong exclusivity, delaying generic entry until patent expiry in 2014, after which generics entered the market.
Q3: Are there similar patents that broaden the protection beyond this patent?
A3: Yes, subsequent patents have extended protection through formulations, dosage forms, and new derivatives, leading to a layered patent landscape.
Q4: How does the patent landscape influence R&D in lipid-lowering drugs?
A4: It steers innovation toward structurally diverse compounds and combination therapies to circumvent existing patents and secure new IP rights.
Q5: What strategic considerations should companies address for developing next-generation statins?
A5: Companies should focus on unique chemical frameworks, improved efficacy, minimized side effects, and comprehensive patent coverage of methods and formulations.
References
- United States Patent 5,616,334. "Method for lowering serum cholesterol levels." Schering-Plough Corporation, 1997.
- Krawczyk, J. et al. Development of Novel HMG-CoA Reductase Inhibitors. Journal of Medicinal Chemistry, 2000.
- Literature on lipid-lowering drug patent trends, including filings by AstraZeneca, Merck, and Pfizer.
More… ↓
⤷ Get Started Free
|
