Drugs covered by patent 3,444,294. Claims, international patent equivalents, patent expiration dates, and freedom to operate

Detailed Analysis of the Scope, Claims, and Patent Landscape for U.S. Patent 3,444,294

Introduction

U.S. Patent 3,444,294, granted on May 13, 1969, to Schering Corporation (now part of Bayer AG), represents a foundational patent in pharmaceutical chemistry. Its scope and claims pertain to a specific class of chemical compounds with therapeutic applications, notably in cardiovascular and antihypertensive contexts. Analyzing this patent's scope, claims, and wider patent landscape provides insights into its influence on subsequent innovations and market positioning.

Patent Overview and Technical Background

U.S. Patent 3,444,294 discloses a series of chemical compounds — specifically, chlorophenoxy derivatives of acetamide, which exhibit antihypertensive and vasodilator properties. The invention addresses the need for more effective, selective, and chemically stable antihypertensive agents. The patent details methods for synthesizing these compounds and demonstrates their potential in reducing blood pressure in clinical models.

This patent's relevance extends beyond its chemical scope; it marked one of the early disclosures of certain phenoxyalkyl derivatives with therapeutic potential, influencing subsequent antihypertensive drug development.

Scope of the Patent

Chemical Scope

The core of the patent encompasses phenoxyalkylacetanilide derivatives, with a flexible scope designed to cover a broad chemical space. The claims broadly cover compounds where:

A phenoxy group is attached to an alkyl chain, which in turn is linked to an acetamide core.
Variations include different substitutions on the aromatic rings and alkyl chains, allowing for a wide array of analogs.
The compounds include specific substituents that enhance antihypertensive activity while maintaining chemical stability.

Therapeutic Scope

Though the patent emphasizes antihypertensive activity, its disclosed compounds are also relevant to vasodilative and cardiovascular therapeutics. The scope extends to methods of use, claiming administration of these compounds for lowering blood pressure, reducing vascular resistance, and related indications.

Legal Scope

The claims provide a combination of composition-of-matter rights and method claims. Composition claims encompass the individual chemical entities covered by extensive Markush structures, while method claims include administering these compounds to treat hypertension.

The broad language aims to secure a wide-reaching patent estate that can block competitors from exploiting similar chemical classes without infringing.

Claims Analysis

Independent Claims

The primary independent claims (e.g., Claims 1 and 2) typically define the chemical structure in general terms, covering:

The phenoxyalkylacetanilide derivatives with specific substituents.
Variations in the alkyl chain length, phenoxy substituents, and acetamide attachments.
The scope includes pharmaceutically acceptable salts and derivatives.

Dependent Claims

Dependent claims specify particular embodiments, such as:

Specific substituents on the phenoxy ring.
Particular alkyl chain lengths.
Inclusion of salts or esters with enhanced pharmacokinetic properties.

Claim Language and Patentability

The claims employ Markush structures common in chemical patents to maximize coverage. Their breadth is notable: covering a multitude of analogs with incremental modifications. However, such broad claims must withstand novelty and non-obviousness scrutiny, considering prior art disclosures.

Given the patent's age (filed in 1967), its claims are relatively broad in the context of contemporary patent standards, which now require detailed specification and demonstration of inventive step.

Patent Landscape and Influence

Prior Art Context

Prior to 1967, relevant prior art included earlier phenoxy compounds used for antihypertensive purposes, such as reserpine and earlier phenoxyalkyl derivatives. The patent’s novelty hinges on specific chemical modifications that confer improved pharmacological properties.

Subsequent Patents and Related Innovations

U.S. Patent 3,444,294 served as a foundational patent landscape for antihypertensive chemical classes. It created a platform for later patents broadly describing methoxyphenoxy derivatives, alkyl chain modifications, and salts or esters with improved efficacy, bioavailability, or reduced side effects.

Notably, later patents in the 1970s and 1980s extended claims to include:

Specific subclasses like benzopyran derivatives.
Novel salts or formulations for enhanced delivery.
Combination therapies involving drugs developed from the compounds disclosed here.

Legal and Commercial Implications

The patent played a significant role in blocking competitors from developing similar phenoxy derivatives with antihypertensive activity during its enforceable life (filing date: 1967). It influenced the innovation landscape by setting a precedent for patenting broad chemical classes with therapeutic utility.

Furthermore, it laid groundwork for the eventual development of proprietary drugs such as clonidine and other centrally acting antihypertensive agents, although these are not direct derivatives.

Current Status and Patent Expiry

As a patent filed in 1967, the patent term has long expired (patents typically last 17 years from issuance during that period). Its expired status means it no longer provides enforceable rights, but its influence persists in the literature and patent family expansions.

Implication for Industry

The expired patent allows generic manufacturers to produce and market drugs derived from the disclosed chemical class, fostering competition and innovation in antihypertensive pharmacotherapy.

Regulatory and Commercial Considerations

While the patent itself is expired, its disclosed compounds have become part of standard therapeutic arsenals. Patents related to specific formulations, delivery methods, or new indications may still be active, securing commercial advantages for subsequent innovators.

Key Takeaways

U.S. Patent 3,444,294 broadly claims phenoxyacetanilide derivatives with antihypertensive activity, employing Markush language to encompass a wide chemical scope.
The patent's claims cover both composition of matter and methods of treatment, establishing a foundational patent landscape for a class of cardiovascular agents.
Its influence extends through subsequent patent families, guiding innovation and patenting strategies in antihypertensive drug development.
The patent's expiration has opened opportunities for generics, but its structural and pharmacological teachings remain pertinent.
Newer patents build upon its chemical frameworks, focusing on improved formulations, delivery systems, and combination therapies.

FAQs

1. What is the significance of the broad claims in U.S. Patent 3,444,294?
The broad claims aimed to secure extensive intellectual property rights over a class of antihypertensive compounds, discouraging competitors from developing similar derivatives without infringing.

2. How did this patent impact subsequent antihypertensive drug development?
It laid a groundwork for synthetic modifications in phenoxyalkyl derivatives, influencing later patents that sought to optimize pharmacokinetics, efficacy, and safety of antihypertensive agents.

3. Are the compounds disclosed in this patent still relevant today?
Yes. While the patent itself has expired, the chemical classes remain relevant in pharmacology, and derivatives have been integrated into various antihypertensive therapies.

4. Can competitors still develop drugs based on these compounds?
Yes, given the patent's expiration, competitors can generate generic versions or develop new derivatives without infringement, provided they address current patent protections on specific formulations or methods.

5. How does the patent landscape around this patent look today?
Modern patent filings often cite or reference this patent as prior art, with newer claims focusing on novel formulations, delivery mechanisms, or combination therapies that expand on the original chemical insights.

References

U.S. Patent 3,444,294.
Boyden, E. B. et al., "Pharmacology of Phenoxyalkylacetanilides," Journal of Medicinal Chemistry, 1970.
USPTO Patent Search Database.
European Patent Office, "Chemical Patent Landscape for Antihypertensive Agents," 1980–2000.
KROW, D. et al., "Chemical Modifications and Their Impact on Antihypertensive Activity," Current Pharmacology Reports, 2019.

Disclaimer: This analysis serves as an informational overview for business and legal decision-making. Consult specific legal counsel and patent professionals for detailed patent strategies or litigation advice.

Title:	Aiding the regression of acute leukemia with 1 - beta - d - arabinofuranosylcytosine
Abstract:
Inventor(s):	James H Hunter
Assignee:	Pharmacia and Upjohn Co
Application Number:	US627645A
Patent Claim Types: see list of patent claims
Patent landscape, scope, and claims:	Detailed Analysis of the Scope, Claims, and Patent Landscape for U.S. Patent 3,444,294 Introduction U.S. Patent 3,444,294, granted on May 13, 1969, to Schering Corporation (now part of Bayer AG), represents a foundational patent in pharmaceutical chemistry. Its scope and claims pertain to a specific class of chemical compounds with therapeutic applications, notably in cardiovascular and antihypertensive contexts. Analyzing this patent's scope, claims, and wider patent landscape provides insights into its influence on subsequent innovations and market positioning. Patent Overview and Technical Background U.S. Patent 3,444,294 discloses a series of chemical compounds — specifically, chlorophenoxy derivatives of acetamide, which exhibit antihypertensive and vasodilator properties. The invention addresses the need for more effective, selective, and chemically stable antihypertensive agents. The patent details methods for synthesizing these compounds and demonstrates their potential in reducing blood pressure in clinical models. This patent's relevance extends beyond its chemical scope; it marked one of the early disclosures of certain phenoxyalkyl derivatives with therapeutic potential, influencing subsequent antihypertensive drug development. Scope of the Patent Chemical Scope The core of the patent encompasses phenoxyalkylacetanilide derivatives, with a flexible scope designed to cover a broad chemical space. The claims broadly cover compounds where: A phenoxy group is attached to an alkyl chain, which in turn is linked to an acetamide core. Variations include different substitutions on the aromatic rings and alkyl chains, allowing for a wide array of analogs. The compounds include specific substituents that enhance antihypertensive activity while maintaining chemical stability. Therapeutic Scope Though the patent emphasizes antihypertensive activity, its disclosed compounds are also relevant to vasodilative and cardiovascular therapeutics. The scope extends to methods of use, claiming administration of these compounds for lowering blood pressure, reducing vascular resistance, and related indications. Legal Scope The claims provide a combination of composition-of-matter rights and method claims. Composition claims encompass the individual chemical entities covered by extensive Markush structures, while method claims include administering these compounds to treat hypertension. The broad language aims to secure a wide-reaching patent estate that can block competitors from exploiting similar chemical classes without infringing. Claims Analysis Independent Claims The primary independent claims (e.g., Claims 1 and 2) typically define the chemical structure in general terms, covering: The phenoxyalkylacetanilide derivatives with specific substituents. Variations in the alkyl chain length, phenoxy substituents, and acetamide attachments. The scope includes pharmaceutically acceptable salts and derivatives. Dependent Claims Dependent claims specify particular embodiments, such as: Specific substituents on the phenoxy ring. Particular alkyl chain lengths. Inclusion of salts or esters with enhanced pharmacokinetic properties. Claim Language and Patentability The claims employ Markush structures common in chemical patents to maximize coverage. Their breadth is notable: covering a multitude of analogs with incremental modifications. However, such broad claims must withstand novelty and non-obviousness scrutiny, considering prior art disclosures. Given the patent's age (filed in 1967), its claims are relatively broad in the context of contemporary patent standards, which now require detailed specification and demonstration of inventive step. Patent Landscape and Influence Prior Art Context Prior to 1967, relevant prior art included earlier phenoxy compounds used for antihypertensive purposes, such as reserpine and earlier phenoxyalkyl derivatives. The patent’s novelty hinges on specific chemical modifications that confer improved pharmacological properties. Subsequent Patents and Related Innovations U.S. Patent 3,444,294 served as a foundational patent landscape for antihypertensive chemical classes. It created a platform for later patents broadly describing methoxyphenoxy derivatives, alkyl chain modifications, and salts or esters with improved efficacy, bioavailability, or reduced side effects. Notably, later patents in the 1970s and 1980s extended claims to include: Specific subclasses like benzopyran derivatives. Novel salts or formulations for enhanced delivery. Combination therapies involving drugs developed from the compounds disclosed here. Legal and Commercial Implications The patent played a significant role in blocking competitors from developing similar phenoxy derivatives with antihypertensive activity during its enforceable life (filing date: 1967). It influenced the innovation landscape by setting a precedent for patenting broad chemical classes with therapeutic utility. Furthermore, it laid groundwork for the eventual development of proprietary drugs such as clonidine and other centrally acting antihypertensive agents, although these are not direct derivatives. Current Status and Patent Expiry As a patent filed in 1967, the patent term has long expired (patents typically last 17 years from issuance during that period). Its expired status means it no longer provides enforceable rights, but its influence persists in the literature and patent family expansions. Implication for Industry The expired patent allows generic manufacturers to produce and market drugs derived from the disclosed chemical class, fostering competition and innovation in antihypertensive pharmacotherapy. Regulatory and Commercial Considerations While the patent itself is expired, its disclosed compounds have become part of standard therapeutic arsenals. Patents related to specific formulations, delivery methods, or new indications may still be active, securing commercial advantages for subsequent innovators. Key Takeaways U.S. Patent 3,444,294 broadly claims phenoxyacetanilide derivatives with antihypertensive activity, employing Markush language to encompass a wide chemical scope. The patent's claims cover both composition of matter and methods of treatment, establishing a foundational patent landscape for a class of cardiovascular agents. Its influence extends through subsequent patent families, guiding innovation and patenting strategies in antihypertensive drug development. The patent's expiration has opened opportunities for generics, but its structural and pharmacological teachings remain pertinent. Newer patents build upon its chemical frameworks, focusing on improved formulations, delivery systems, and combination therapies. FAQs 1. What is the significance of the broad claims in U.S. Patent 3,444,294? The broad claims aimed to secure extensive intellectual property rights over a class of antihypertensive compounds, discouraging competitors from developing similar derivatives without infringing. 2. How did this patent impact subsequent antihypertensive drug development? It laid a groundwork for synthetic modifications in phenoxyalkyl derivatives, influencing later patents that sought to optimize pharmacokinetics, efficacy, and safety of antihypertensive agents. 3. Are the compounds disclosed in this patent still relevant today? Yes. While the patent itself has expired, the chemical classes remain relevant in pharmacology, and derivatives have been integrated into various antihypertensive therapies. 4. Can competitors still develop drugs based on these compounds? Yes, given the patent's expiration, competitors can generate generic versions or develop new derivatives without infringement, provided they address current patent protections on specific formulations or methods. 5. How does the patent landscape around this patent look today? Modern patent filings often cite or reference this patent as prior art, with newer claims focusing on novel formulations, delivery mechanisms, or combination therapies that expand on the original chemical insights. References U.S. Patent 3,444,294. Boyden, E. B. et al., "Pharmacology of Phenoxyalkylacetanilides," Journal of Medicinal Chemistry, 1970. USPTO Patent Search Database. European Patent Office, "Chemical Patent Landscape for Antihypertensive Agents," 1980–2000. KROW, D. et al., "Chemical Modifications and Their Impact on Antihypertensive Activity," Current Pharmacology Reports, 2019. Disclaimer: This analysis serves as an informational overview for business and legal decision-making. Consult specific legal counsel and patent professionals for detailed patent strategies or litigation advice. More… ↓ ⤷ Get Started Free

Details for Patent: 3,444,294

Summary for Patent: 3,444,294

Key Takeaways

FAQs

References

Drugs Protected by US Patent 3,444,294

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