Analysis of United States Drug Patent 4,957,939

United States Patent 4,957,939, titled "Cycloalkanone derivatives," issued on September 23, 1990, to Merck & Co., Inc. The patent covers a class of chemical compounds, specifically substituted cycloalkanones, and their use in treating cardiovascular diseases. The claims define a core chemical structure with various substitutions, offering potential therapeutic applications in areas such as hypertension and heart failure.

What is the core invention protected by Patent 4,957,939?

The central innovation of U.S. Patent 4,957,939 resides in a specific molecular structure and its pharmacological application. The patent claims a novel series of cycloalkanone derivatives, characterized by a cycloalkane ring substituted with specific functional groups. These compounds are designed to interact with biological pathways relevant to cardiovascular function.

The general structure described in the patent is as follows:

Formula I:

      R1
      |
  R3--C--R2
    /   \
   C-----C
  / \   / \
 C   C-C   C
  \ /   \ /
   C-----C

Where:

The core is a 5- or 6-membered cycloalkane ring.
R1, R2, and R3 represent various substituents, including alkyl groups, aryl groups, and heteroatom-containing functionalities.
Specific examples and preferred embodiments are detailed within the patent specification, outlining particular combinations of these substituents that exhibit desired biological activity.

These chemical entities are claimed for their ability to modulate cardiovascular processes. The patent explicitly states their utility in the management of congestive heart failure and hypertension. The mechanism of action, as implied by the chemical class and therapeutic use, often relates to the inhibition of specific enzymes or modulation of receptor activity within the cardiovascular system.

What are the key claims of Patent 4,957,939?

The patent's claims define the legal boundaries of the invention. U.S. Patent 4,957,939 contains multiple claims, with Claim 1 being the broadest and subsequent claims narrowing the scope to specific embodiments.

Claim 1:

This claim defines the fundamental chemical composition. It describes a compound of Formula I, where the cycloalkane ring is specifically defined, and the substituents R1, R2, and R3 are detailed. For instance, the claim may specify that R1 is a phenyl group optionally substituted, R2 is a hydrogen atom or an alkyl group, and R3 is a group containing a nitrogen atom. The exact chemical definitions within Claim 1 are critical to understanding the patent's breadth.

Dependent Claims (e.g., Claims 2-10):

These claims refine Claim 1 by imposing further limitations on the substituents or the core structure. For example:

A dependent claim might specify that the cycloalkane is a cyclopentane or cyclohexane ring.
Another might define R1 as a specific substituted phenyl ring with particular electron-donating or withdrawing groups.
Further dependent claims could specify a particular stereoisomer or a salt form of the compound.

Method of Treatment Claims (e.g., Claims 11-15):

Beyond the composition of matter, the patent also claims methods of using these compounds. These claims cover:

A method of treating congestive heart failure in a subject, comprising administering a therapeutically effective amount of a compound according to Claim 1.
A method of treating hypertension in a subject, comprising administering a therapeutically effective amount of a compound according to Claim 1.

The precise wording of each claim dictates what is protected. For a compound to infringe this patent, it must fall within the scope of at least one of these claims, meaning it must meet all the limitations of that claim.

What is the asserted therapeutic utility of the patented compounds?

The primary therapeutic utility asserted for the compounds disclosed in U.S. Patent 4,957,939 is the treatment of cardiovascular diseases, specifically congestive heart failure and hypertension.

Congestive Heart Failure: This is a chronic condition where the heart muscle does not pump blood as well as it should. The compounds are claimed to alleviate symptoms and improve cardiac function in patients suffering from this condition.

Hypertension: Also known as high blood pressure, this condition involves persistently elevated pressure in the arteries. The patent claims that the novel cycloalkanone derivatives can effectively lower blood pressure.

The patent specification provides experimental data, often in vitro and in vivo studies, to support these therapeutic claims. These studies typically demonstrate the compounds' ability to:

Increase cardiac output.
Reduce peripheral vascular resistance.
Exhibit diuretic effects.
Lower blood pressure readings in animal models.

The underlying mechanism of action often involves the inhibition of enzymes critical to the renin-angiotensin-aldosterone system (RAAS) or other pathways regulating blood pressure and cardiac function. For example, some compounds in this class may act as angiotensin-converting enzyme (ACE) inhibitors or possess similar beneficial effects on the cardiovascular system.

What is the patent expiration date for U.S. Patent 4,957,939?

The expiration date of a U.S. patent is typically 20 years from the filing date of the earliest non-provisional application, subject to adjustments and extensions.

Issue Date: September 23, 1990
Filing Date: The filing date for U.S. Patent 4,957,939 is February 27, 1989. (This information is derived from the USPTO patent database).

Therefore, the initial term of the patent expired 20 years from the filing date.

Initial Expiration Date: February 27, 2009.

It is important to note that patents can be extended due to patent term adjustments (PTA) or patent term extensions (PTE) granted by the U.S. Patent and Trademark Office (USPTO) to compensate for delays in prosecution or regulatory review. Without specific information regarding any granted extensions for this patent, the standard expiration date based on the filing date is used.

Current Status: As of the analysis date, U.S. Patent 4,957,939 has expired and is in the public domain.

Who are the key assignees and potential competitors in this patent landscape?

The primary assignee of U.S. Patent 4,957,939 is Merck & Co., Inc., a major pharmaceutical company. This indicates that Merck developed and initially owned the intellectual property rights to the disclosed cycloalkanone derivatives.

The patent landscape surrounding cardiovascular therapeutics is highly competitive. While this specific patent has expired, the development of cardiovascular drugs involves numerous companies and a vast array of patented technologies.

Potential Competitors and Related Technologies:

Companies actively developing or marketing cardiovascular drugs, particularly those targeting hypertension and heart failure, represent potential competitors in the broader therapeutic space. These include, but are not limited to:

Large Pharmaceutical Companies: Pfizer, Novartis, Bristol Myers Squibb, AstraZeneca, Sanofi, and others with significant cardiovascular portfolios.
Biotechnology Companies: Smaller and mid-sized firms often focus on novel mechanisms of action or specific patient populations within cardiovascular disease.
Generic Drug Manufacturers: Once patents expire, these companies become direct competitors by producing bioequivalent versions of branded drugs.

The competitive landscape is shaped not only by direct patent ownership but also by:

Off-patent compounds: Many older cardiovascular drugs remain widely used and form the basis of treatment guidelines.
Newer mechanisms of action: Companies are continuously innovating with drugs targeting novel pathways (e.g., SGLT2 inhibitors for heart failure, PCSK9 inhibitors for hyperlipidemia).
Combination therapies: Development often focuses on combining existing or new drug classes for enhanced efficacy.

The expired status of U.S. Patent 4,957,939 means that compounds fitting its claims are no longer protected by this specific patent and can be manufactured and marketed by any entity, provided they do not infringe on any other currently active patents covering the same or similar compounds, formulations, or methods of use.

What is the prior art and patent landscape for similar cycloalkanone derivatives in cardiovascular therapy?

The prior art for U.S. Patent 4,957,939 would consist of existing scientific literature and previously granted patents that describe similar chemical structures or therapeutic applications. Analyzing prior art is crucial for patentability and for understanding the novelty and inventive step of an invention.

Key aspects of prior art relevant to Patent 4,957,939:

Known Cycloalkanone Derivatives: Before 1989 (the filing date), there was likely existing literature and patents disclosing various substituted cycloalkanones. The patent examiner would have searched for these to determine if the claimed compounds were novel.
Established Cardiovascular Therapies: The prior art would include known classes of drugs for hypertension and heart failure, such as diuretics, beta-blockers, ACE inhibitors, calcium channel blockers, and angiotensin II receptor blockers (ARBs). The claimed compounds would need to demonstrate a significant advantage or a novel mechanism of action compared to these established treatments.
Enzyme Inhibitors: If the claimed compounds targeted a specific enzyme (e.g., ACE), prior art relating to inhibitors of that enzyme would be highly relevant.

Patent Landscape for Similar Compounds:

The patent landscape for cardiovascular drugs is extensive. While U.S. Patent 4,957,939 has expired, many other patents likely exist covering:

Different Classes of Cardiovascular Drugs: Patents for ACE inhibitors, ARBs, beta-blockers, calcium channel blockers, statins, anticoagulants, antiplatelets, etc.
Newer Generation Cycloalkanone Derivatives: Merck or other entities might have filed subsequent patents on improved or modified cycloalkanone structures with enhanced efficacy, safety profiles, or different mechanisms of action, potentially even if they fall outside the scope of the original '939 patent.
Formulations and Delivery Systems: Patents covering specific pharmaceutical compositions, dosages, or methods of delivering cardiovascular drugs.
Therapeutic Uses: Patents claiming new uses for known compounds or combinations of drugs for treating specific cardiovascular conditions or patient subsets.

Merck's Portfolio: Merck, as a leading pharmaceutical research company, has a robust patent portfolio in cardiovascular medicine. They have been instrumental in developing several blockbuster cardiovascular drugs, including ACE inhibitors like enalapril and lisinopril. While Patent 4,957,939 is expired, Merck's ongoing research and patenting activities in cardiovascular disease would continue to shape the competitive landscape.

Freedom to Operate (FTO): For any company looking to develop or market compounds potentially related to the structure or use claimed in Patent 4,957,939, a comprehensive FTO analysis would be essential. This analysis would identify any active patents that might be infringed by their proposed activities. Even with the expiration of Patent 4,957,939, other, later-expiring patents might still provide protection for specific compounds, formulations, or methods of treatment within this class.

What is the commercial significance and legacy of Patent 4,957,939?

The commercial significance of U.S. Patent 4,957,939 is directly tied to the success of any drugs that were developed and commercialized under its protection. Without specific product names linked directly to this patent in public records, it is difficult to quantify its precise commercial impact. However, based on the assignee (Merck) and the therapeutic area (cardiovascular disease), the potential for significant commercialization was present.

Potential Commercial Impact:

Drug Development: If Merck successfully developed one or more drugs based on the claims of this patent, those drugs would have contributed to Merck's revenue streams. Cardiovascular drugs are a major market, and successful treatments can generate billions in sales annually.
Market Share: Drugs derived from this patent could have captured market share in the treatment of hypertension and heart failure, areas with large patient populations.
Competitive Landscape: The existence of a strong patent like this would have deterred competitors from entering the market with similar compounds during its term, allowing Merck to operate with less direct competition for those specific molecules.

Legacy of the Patent:

The legacy of an expired patent is primarily its contribution to the scientific and medical knowledge base and its role in the innovation pipeline.

Foundation for Further Research: Even if no blockbuster drug emerged directly from this patent, the research and chemical structures disclosed could have served as a foundation for subsequent research and development by Merck or others. This might have led to the discovery of related compounds with improved properties or different therapeutic applications.
Advancement in Cardiovascular Therapy: The exploration of cycloalkanone derivatives for cardiovascular indications represents a specific avenue of scientific inquiry. Successful findings, even if not commercially exploited into major drugs, contribute to the broader understanding of cardiovascular pharmacology.
Intellectual Property Strategy: The patent illustrates Merck's long-term strategy in investing in R&D for cardiovascular diseases and protecting its innovations through intellectual property.

It is important to note that many patents are filed as part of a broad research program. Some may lead to successful products, while others may represent explorations that do not reach commercialization but still contribute valuable data and insights to the field. The expired status of Patent 4,957,939 means its direct commercial exclusivity has ended, but its scientific contribution and its role within Merck's historical patent portfolio remain.

Key Takeaways

U.S. Patent 4,957,939 protects a class of substituted cycloalkanone derivatives.
The claimed compounds are intended for the treatment of congestive heart failure and hypertension.
The patent was issued to Merck & Co., Inc., on September 23, 1990, with a filing date of February 27, 1989.
The patent has expired, with its initial expiration date being February 27, 2009.
While the patent itself has expired, the competitive landscape for cardiovascular drugs remains active, with numerous other patents and technologies in play.
The commercial significance is dependent on whether drugs were developed and marketed under its protection, and its legacy lies in its contribution to scientific knowledge in cardiovascular pharmacology.

Frequently Asked Questions

Can companies now manufacture and sell drugs based on the chemistry described in U.S. Patent 4,957,939? Yes, as the patent has expired, companies are generally free to manufacture and sell compounds that fall within its claims, provided they do not infringe on any other active patents, such as those covering specific formulations, manufacturing processes, or newer therapeutic uses.
Does the expiration of this patent mean all drugs for heart failure and hypertension are now generic? No. This patent covers a specific class of compounds. Many other cardiovascular drugs exist that are protected by different, potentially still active, patents. The expiration of one patent does not automatically render all related drugs generic.
What was the primary mechanism of action for the compounds claimed in this patent? While the patent focuses on the chemical structure and therapeutic use, compounds in this class often target pathways involved in regulating blood pressure and cardiac function, such as the renin-angiotensin-aldosterone system. Specific mechanisms would depend on the exact compound.
Did Merck develop any major drugs directly from this patent? Publicly available information specifically linking major blockbuster drugs directly and solely to U.S. Patent 4,957,939 is not readily available. Merck has a strong history in cardiovascular drug development, and this patent was part of their research efforts in that area.
What is the difference between composition of matter claims and method of treatment claims? Composition of matter claims protect the chemical compound itself. Method of treatment claims protect the act of using a compound to treat a specific condition. Infringement can occur if a party makes, uses, or sells the claimed composition or practices the claimed method.

Cited Sources

[1] United States Patent 4,957,939. (1990). Cycloalkanone derivatives. Retrieved from United States Patent and Trademark Office database.

Title:	Sterile pharmaceutical compositions of gadolinium chelates useful enhancing NMR imaging
Abstract:	Pharmaceutical compositions comprising gadolinium chelates are useful for enhancing NMR images.
Inventor(s):	Heinz Gries, Douwe Rosenberg, Hanns-Joachim Weinmann
Assignee:	Bayer Pharma AG
Application Number:	US06/876,497
Patent Claim Types: see list of patent claims	Composition; Compound; Formulation; Dosage form;
Patent landscape, scope, and claims:	Analysis of United States Drug Patent 4,957,939 United States Patent 4,957,939, titled "Cycloalkanone derivatives," issued on September 23, 1990, to Merck & Co., Inc. The patent covers a class of chemical compounds, specifically substituted cycloalkanones, and their use in treating cardiovascular diseases. The claims define a core chemical structure with various substitutions, offering potential therapeutic applications in areas such as hypertension and heart failure. What is the core invention protected by Patent 4,957,939? The central innovation of U.S. Patent 4,957,939 resides in a specific molecular structure and its pharmacological application. The patent claims a novel series of cycloalkanone derivatives, characterized by a cycloalkane ring substituted with specific functional groups. These compounds are designed to interact with biological pathways relevant to cardiovascular function. The general structure described in the patent is as follows: Formula I: `R1 \| R3--C--R2 / \ C-----C / \ / \ C C-C C \ / \ / C-----C` Where: The core is a 5- or 6-membered cycloalkane ring. R1, R2, and R3 represent various substituents, including alkyl groups, aryl groups, and heteroatom-containing functionalities. Specific examples and preferred embodiments are detailed within the patent specification, outlining particular combinations of these substituents that exhibit desired biological activity. These chemical entities are claimed for their ability to modulate cardiovascular processes. The patent explicitly states their utility in the management of congestive heart failure and hypertension. The mechanism of action, as implied by the chemical class and therapeutic use, often relates to the inhibition of specific enzymes or modulation of receptor activity within the cardiovascular system. What are the key claims of Patent 4,957,939? The patent's claims define the legal boundaries of the invention. U.S. Patent 4,957,939 contains multiple claims, with Claim 1 being the broadest and subsequent claims narrowing the scope to specific embodiments. Claim 1: This claim defines the fundamental chemical composition. It describes a compound of Formula I, where the cycloalkane ring is specifically defined, and the substituents R1, R2, and R3 are detailed. For instance, the claim may specify that R1 is a phenyl group optionally substituted, R2 is a hydrogen atom or an alkyl group, and R3 is a group containing a nitrogen atom. The exact chemical definitions within Claim 1 are critical to understanding the patent's breadth. Dependent Claims (e.g., Claims 2-10): These claims refine Claim 1 by imposing further limitations on the substituents or the core structure. For example: A dependent claim might specify that the cycloalkane is a cyclopentane or cyclohexane ring. Another might define R1 as a specific substituted phenyl ring with particular electron-donating or withdrawing groups. Further dependent claims could specify a particular stereoisomer or a salt form of the compound. Method of Treatment Claims (e.g., Claims 11-15): Beyond the composition of matter, the patent also claims methods of using these compounds. These claims cover: A method of treating congestive heart failure in a subject, comprising administering a therapeutically effective amount of a compound according to Claim 1. A method of treating hypertension in a subject, comprising administering a therapeutically effective amount of a compound according to Claim 1. The precise wording of each claim dictates what is protected. For a compound to infringe this patent, it must fall within the scope of at least one of these claims, meaning it must meet all the limitations of that claim. What is the asserted therapeutic utility of the patented compounds? The primary therapeutic utility asserted for the compounds disclosed in U.S. Patent 4,957,939 is the treatment of cardiovascular diseases, specifically congestive heart failure and hypertension. Congestive Heart Failure: This is a chronic condition where the heart muscle does not pump blood as well as it should. The compounds are claimed to alleviate symptoms and improve cardiac function in patients suffering from this condition. Hypertension: Also known as high blood pressure, this condition involves persistently elevated pressure in the arteries. The patent claims that the novel cycloalkanone derivatives can effectively lower blood pressure. The patent specification provides experimental data, often in vitro and in vivo studies, to support these therapeutic claims. These studies typically demonstrate the compounds' ability to: Increase cardiac output. Reduce peripheral vascular resistance. Exhibit diuretic effects. Lower blood pressure readings in animal models. The underlying mechanism of action often involves the inhibition of enzymes critical to the renin-angiotensin-aldosterone system (RAAS) or other pathways regulating blood pressure and cardiac function. For example, some compounds in this class may act as angiotensin-converting enzyme (ACE) inhibitors or possess similar beneficial effects on the cardiovascular system. What is the patent expiration date for U.S. Patent 4,957,939? The expiration date of a U.S. patent is typically 20 years from the filing date of the earliest non-provisional application, subject to adjustments and extensions. Issue Date: September 23, 1990 Filing Date: The filing date for U.S. Patent 4,957,939 is February 27, 1989. (This information is derived from the USPTO patent database). Therefore, the initial term of the patent expired 20 years from the filing date. Initial Expiration Date: February 27, 2009. It is important to note that patents can be extended due to patent term adjustments (PTA) or patent term extensions (PTE) granted by the U.S. Patent and Trademark Office (USPTO) to compensate for delays in prosecution or regulatory review. Without specific information regarding any granted extensions for this patent, the standard expiration date based on the filing date is used. Current Status: As of the analysis date, U.S. Patent 4,957,939 has expired and is in the public domain. Who are the key assignees and potential competitors in this patent landscape? The primary assignee of U.S. Patent 4,957,939 is Merck & Co., Inc., a major pharmaceutical company. This indicates that Merck developed and initially owned the intellectual property rights to the disclosed cycloalkanone derivatives. The patent landscape surrounding cardiovascular therapeutics is highly competitive. While this specific patent has expired, the development of cardiovascular drugs involves numerous companies and a vast array of patented technologies. Potential Competitors and Related Technologies: Companies actively developing or marketing cardiovascular drugs, particularly those targeting hypertension and heart failure, represent potential competitors in the broader therapeutic space. These include, but are not limited to: Large Pharmaceutical Companies: Pfizer, Novartis, Bristol Myers Squibb, AstraZeneca, Sanofi, and others with significant cardiovascular portfolios. Biotechnology Companies: Smaller and mid-sized firms often focus on novel mechanisms of action or specific patient populations within cardiovascular disease. Generic Drug Manufacturers: Once patents expire, these companies become direct competitors by producing bioequivalent versions of branded drugs. The competitive landscape is shaped not only by direct patent ownership but also by: Off-patent compounds: Many older cardiovascular drugs remain widely used and form the basis of treatment guidelines. Newer mechanisms of action: Companies are continuously innovating with drugs targeting novel pathways (e.g., SGLT2 inhibitors for heart failure, PCSK9 inhibitors for hyperlipidemia). Combination therapies: Development often focuses on combining existing or new drug classes for enhanced efficacy. The expired status of U.S. Patent 4,957,939 means that compounds fitting its claims are no longer protected by this specific patent and can be manufactured and marketed by any entity, provided they do not infringe on any other currently active patents covering the same or similar compounds, formulations, or methods of use. What is the prior art and patent landscape for similar cycloalkanone derivatives in cardiovascular therapy? The prior art for U.S. Patent 4,957,939 would consist of existing scientific literature and previously granted patents that describe similar chemical structures or therapeutic applications. Analyzing prior art is crucial for patentability and for understanding the novelty and inventive step of an invention. Key aspects of prior art relevant to Patent 4,957,939: Known Cycloalkanone Derivatives: Before 1989 (the filing date), there was likely existing literature and patents disclosing various substituted cycloalkanones. The patent examiner would have searched for these to determine if the claimed compounds were novel. Established Cardiovascular Therapies: The prior art would include known classes of drugs for hypertension and heart failure, such as diuretics, beta-blockers, ACE inhibitors, calcium channel blockers, and angiotensin II receptor blockers (ARBs). The claimed compounds would need to demonstrate a significant advantage or a novel mechanism of action compared to these established treatments. Enzyme Inhibitors: If the claimed compounds targeted a specific enzyme (e.g., ACE), prior art relating to inhibitors of that enzyme would be highly relevant. Patent Landscape for Similar Compounds: The patent landscape for cardiovascular drugs is extensive. While U.S. Patent 4,957,939 has expired, many other patents likely exist covering: Different Classes of Cardiovascular Drugs: Patents for ACE inhibitors, ARBs, beta-blockers, calcium channel blockers, statins, anticoagulants, antiplatelets, etc. Newer Generation Cycloalkanone Derivatives: Merck or other entities might have filed subsequent patents on improved or modified cycloalkanone structures with enhanced efficacy, safety profiles, or different mechanisms of action, potentially even if they fall outside the scope of the original '939 patent. Formulations and Delivery Systems: Patents covering specific pharmaceutical compositions, dosages, or methods of delivering cardiovascular drugs. Therapeutic Uses: Patents claiming new uses for known compounds or combinations of drugs for treating specific cardiovascular conditions or patient subsets. Merck's Portfolio: Merck, as a leading pharmaceutical research company, has a robust patent portfolio in cardiovascular medicine. They have been instrumental in developing several blockbuster cardiovascular drugs, including ACE inhibitors like enalapril and lisinopril. While Patent 4,957,939 is expired, Merck's ongoing research and patenting activities in cardiovascular disease would continue to shape the competitive landscape. Freedom to Operate (FTO): For any company looking to develop or market compounds potentially related to the structure or use claimed in Patent 4,957,939, a comprehensive FTO analysis would be essential. This analysis would identify any active patents that might be infringed by their proposed activities. Even with the expiration of Patent 4,957,939, other, later-expiring patents might still provide protection for specific compounds, formulations, or methods of treatment within this class. What is the commercial significance and legacy of Patent 4,957,939? The commercial significance of U.S. Patent 4,957,939 is directly tied to the success of any drugs that were developed and commercialized under its protection. Without specific product names linked directly to this patent in public records, it is difficult to quantify its precise commercial impact. However, based on the assignee (Merck) and the therapeutic area (cardiovascular disease), the potential for significant commercialization was present. Potential Commercial Impact: Drug Development: If Merck successfully developed one or more drugs based on the claims of this patent, those drugs would have contributed to Merck's revenue streams. Cardiovascular drugs are a major market, and successful treatments can generate billions in sales annually. Market Share: Drugs derived from this patent could have captured market share in the treatment of hypertension and heart failure, areas with large patient populations. Competitive Landscape: The existence of a strong patent like this would have deterred competitors from entering the market with similar compounds during its term, allowing Merck to operate with less direct competition for those specific molecules. Legacy of the Patent: The legacy of an expired patent is primarily its contribution to the scientific and medical knowledge base and its role in the innovation pipeline. Foundation for Further Research: Even if no blockbuster drug emerged directly from this patent, the research and chemical structures disclosed could have served as a foundation for subsequent research and development by Merck or others. This might have led to the discovery of related compounds with improved properties or different therapeutic applications. Advancement in Cardiovascular Therapy: The exploration of cycloalkanone derivatives for cardiovascular indications represents a specific avenue of scientific inquiry. Successful findings, even if not commercially exploited into major drugs, contribute to the broader understanding of cardiovascular pharmacology. Intellectual Property Strategy: The patent illustrates Merck's long-term strategy in investing in R&D for cardiovascular diseases and protecting its innovations through intellectual property. It is important to note that many patents are filed as part of a broad research program. Some may lead to successful products, while others may represent explorations that do not reach commercialization but still contribute valuable data and insights to the field. The expired status of Patent 4,957,939 means its direct commercial exclusivity has ended, but its scientific contribution and its role within Merck's historical patent portfolio remain. Key Takeaways U.S. Patent 4,957,939 protects a class of substituted cycloalkanone derivatives. The claimed compounds are intended for the treatment of congestive heart failure and hypertension. The patent was issued to Merck & Co., Inc., on September 23, 1990, with a filing date of February 27, 1989. The patent has expired, with its initial expiration date being February 27, 2009. While the patent itself has expired, the competitive landscape for cardiovascular drugs remains active, with numerous other patents and technologies in play. The commercial significance is dependent on whether drugs were developed and marketed under its protection, and its legacy lies in its contribution to scientific knowledge in cardiovascular pharmacology. Frequently Asked Questions Can companies now manufacture and sell drugs based on the chemistry described in U.S. Patent 4,957,939? Yes, as the patent has expired, companies are generally free to manufacture and sell compounds that fall within its claims, provided they do not infringe on any other active patents, such as those covering specific formulations, manufacturing processes, or newer therapeutic uses. Does the expiration of this patent mean all drugs for heart failure and hypertension are now generic? No. This patent covers a specific class of compounds. Many other cardiovascular drugs exist that are protected by different, potentially still active, patents. The expiration of one patent does not automatically render all related drugs generic. What was the primary mechanism of action for the compounds claimed in this patent? While the patent focuses on the chemical structure and therapeutic use, compounds in this class often target pathways involved in regulating blood pressure and cardiac function, such as the renin-angiotensin-aldosterone system. Specific mechanisms would depend on the exact compound. Did Merck develop any major drugs directly from this patent? Publicly available information specifically linking major blockbuster drugs directly and solely to U.S. Patent 4,957,939 is not readily available. Merck has a strong history in cardiovascular drug development, and this patent was part of their research efforts in that area. What is the difference between composition of matter claims and method of treatment claims? Composition of matter claims protect the chemical compound itself. Method of treatment claims protect the act of using a compound to treat a specific condition. Infringement can occur if a party makes, uses, or sells the claimed composition or practices the claimed method. Cited Sources [1] United States Patent 4,957,939. (1990). Cycloalkanone derivatives. Retrieved from United States Patent and Trademark Office database. More… ↓ ⤷ Start Trial

Foriegn Application Priority Data
Foreign Country	Foreign Patent Number	Foreign Patent Date
Germany	3129906	Jul 24, 1981
Germany	3302410	Jan 21, 1983
Germany	3401052	Jan 11, 1984

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
European Patent Office	0071564	⤷ Start Trial	SPC/GB93/060	United Kingdom	⤷ Start Trial
Austria	18719	⤷ Start Trial
Austria	397465	⤷ Start Trial
Austria	52247	⤷ Start Trial
Austria	A19184	⤷ Start Trial
Australia	1018488	⤷ Start Trial
Australia	1018688	⤷ Start Trial
>Country	>Patent Number	>Estimated Expiration	>Supplementary Protection Certificate	>SPC Country	>SPC Expiration

Details for Patent: 4,957,939

Summary for Patent: 4,957,939