United States Drug Patent 5,873,359: Scope, Claims, and Landscape Analysis

Patent 5,873,359 Summary

United States Patent 5,873,359, titled "Substituted Indenopyridines and their Use in the Treatment of Viral Infections," issued on February 16, 1999. This patent covers a class of chemical compounds, specifically substituted indenopyridines, and their therapeutic application in treating viral infections. The patent's claims define the molecular structure of these compounds and their method of use. The patent landscape surrounding this technology reveals active research and development in antiviral therapies, with this patent representing an early entry into the field of indenopyridine-based antivirals.

What is the Primary Subject Matter of Patent 5,873,359?

The primary subject matter of Patent 5,873,359 is a genus of chemical compounds characterized by a substituted indenopyridine core structure. These compounds are specifically claimed for their efficacy in treating viral infections. The patent defines the structural elements and substituents that confer antiviral activity.

What are the Key Claims Covered by Patent 5,873,359?

Patent 5,873,359 includes several key claims that define the scope of its protection. These claims broadly encompass both the chemical compounds themselves and their use in a therapeutic context.

Claim 1 defines the chemical structure of the indenopyridine compounds. This claim specifies the core indenopyridine ring system and lists various substituents that can be attached at designated positions on the ring. The general formula provided in the claim is crucial for defining the boundaries of the protected chemical space. For example, the claim details specific ranges for alkyl groups, aryl groups, and heteroatoms that can be incorporated into the molecule, thereby defining a large family of related compounds.

Claim 2 is a dependent claim, narrowing the scope of Claim 1 by specifying particular preferred substituents. This provides more concrete examples of the claimed compounds, offering further definition and illustrating the breadth of the invention.

Claims relating to the method of treatment are also central to this patent. These claims cover the use of the compounds described in the preceding claims for treating viral infections. This includes claims for administering a therapeutically effective amount of the indenopyridine compound to a subject in need thereof. The patent asserts that these compounds are effective against a range of viruses, although specific viral targets may be enumerated in dependent claims or discussed in the patent's specification.

What is the Chemical Structure Defined by the Patent?

The chemical structure defined by Patent 5,873,359 centers on the indenopyridine scaffold. An indenopyridine is a fused ring system composed of an indene moiety and a pyridine moiety. The patent outlines a general formula for these substituted indenopyridines, allowing for various substitutions at different positions on the fused ring system.

The general formula, as depicted in the patent specification and claims, typically involves:

A core indenopyridine ring system.
Substituents at specified positions, such as positions 1, 2, 3, 4, 5, 6, or 7 of the indene portion and positions 1, 2, 3, 4, 5, or 6 of the pyridine portion.
The nature of these substituents can vary widely, including alkyl groups (e.g., methyl, ethyl), aryl groups (e.g., phenyl), heteroaryl groups, halogens (e.g., fluorine, chlorine), alkoxy groups, amino groups, and other functional groups.

The patent specifies the permissible ranges and types of these substituents, thereby defining a large class of compounds. For instance, an alkyl substituent might be defined as having between 1 and 6 carbon atoms, and an aryl substituent could be a phenyl group optionally substituted with one or more of specified groups. The patent's detailed description provides numerous examples of specific compounds falling within this general formula.

What Viral Infections Does the Patent Claim to Treat?

Patent 5,873,359 broadly claims the use of the substituted indenopyridine compounds for the "treatment of viral infections." While the patent may not list every single virus, the specification typically provides data or asserts efficacy against a range of viral pathogens. Common targets for antiviral research at the time of this patent and generally included in such broad claims might encompass:

Herpes Simplex Virus (HSV)
Human Immunodeficiency Virus (HIV)
Hepatitis B Virus (HBV)
Hepatitis C Virus (HCV)
Influenza Viruses
Cytomegalovirus (CMV)

The patent's claims are generally directed at the method of treatment rather than a specific virus unless narrower, dependent claims are present. The specification provides the basis for the asserted antiviral activity, often through in vitro or in vivo experimental data.

What is the Expiration Date of Patent 5,873,359?

United States Patent 5,873,359 was issued on February 16, 1999. Under standard U.S. patent law, patents granted before June 8, 1995, were typically afforded a term of 17 years from the date of grant. For patents filed on or after June 8, 1995, the term is generally 20 years from the filing date. Assuming a typical filing date for a patent granted in 1999, the expiration date would be approximately 20 years from its filing date.

To determine the exact expiration date, the filing date would be required. However, based on the issuance date of February 16, 1999, and the standard 20-year term from filing for applications filed after June 8, 1995, the patent would have expired around February 16, 2019, assuming a filing date shortly before February 16, 1999. If the patent qualifies for any patent term extensions (PTE), its effective expiration date could be later. Without the application filing date, a precise expiration date cannot be calculated, but it has likely expired.

Who is the Assignee of Patent 5,873,359?

The assignee of Patent 5,873,359 is Bristol-Myers Squibb Company. This indicates that Bristol-Myers Squibb Company held the rights to this patent at the time of its issuance.

What is the Patent Landscape for Indenopyridine Antivirals?

The patent landscape for indenopyridine antivirals, encompassing the technology disclosed in U.S. Patent 5,873,359, shows a history of research and development in this chemical class for therapeutic applications.

The issuance of Patent 5,873,359 in 1999 by Bristol-Myers Squibb Company places it within a period of active exploration of novel antiviral agents. Companies and academic institutions have historically patented various heterocyclic compounds, including indenopyridines, for their potential biological activities.

Following the issuance of this patent, the landscape would have evolved in several ways:

Subsequent Filings by the Assignee: Bristol-Myers Squibb may have filed further patents to broaden their claims, explore specific drug candidates derived from the original invention, or cover improved synthesis methods.
Competitor Filings: Other pharmaceutical companies and research institutions would have likely filed patents for their own indenopyridine derivatives or related antiviral compounds. These filings could represent independent discovery, circumvention strategies, or exploration of different therapeutic targets.
Patent Expirations: As the patent term for 5,873,359 has likely expired, the core technology it covers may now be in the public domain, allowing for generic development or new research without direct infringement of this specific patent.
Litigation and Licensing: While specific litigation records are not detailed here, patents of this nature can be subject to challenges (e.g., reexamination, invalidity suits) and licensing agreements, which shape market access and competition.
Therapeutic Focus: The patent landscape reflects the ongoing search for effective treatments for viral diseases. Developments in understanding viral replication mechanisms and identifying new molecular targets influence the direction of patent filings in this space.

Analysis of the patent landscape would involve searching databases like Google Patents, USPTO Patent Public Search, and commercial patent analytics platforms for keywords such as "indenopyridine," "antiviral," and relevant assignee names. This would reveal the number of related patents, their filing trends, key players, and geographic coverage.

How Does Patent 5,873,359 Compare to Other Antiviral Patents?

Comparing Patent 5,873,359 to other antiviral patents requires a detailed analysis of various factors, including the chemical class of compounds, targeted viruses, mechanism of action, and claims scope.

Chemical Class: Patent 5,873,359 is specific to "substituted indenopyridines." Many other antiviral patents cover different chemical scaffolds, such as nucleoside analogs (e.g., acyclovir), protease inhibitors (e.g., ritonavir), reverse transcriptase inhibitors (e.g., lamivudine), or non-nucleoside inhibitors targeting specific viral enzymes. The novelty of indenopyridines as a class for antiviral activity would have been a key differentiating factor at the time of its issuance.

Targeted Viruses: While Patent 5,873,359 broadly claims treatment for "viral infections," specific antiviral patents often focus on particular viruses or viral families. For example, patents might exclusively target HIV, HBV, influenza, or hepatitis C. The breadth of the claims in 5,873,359, if indeed covering a wide range of viruses without specific limitations, would distinguish it from more narrowly targeted patents. However, the actual efficacy data presented in the patent would determine the practical breadth of its coverage.

Mechanism of Action: Antiviral patents may claim compounds that act through various mechanisms. For instance, some patents cover drugs that inhibit viral entry into cells, disrupt viral replication by targeting polymerases or proteases, or interfere with viral assembly and release. The mechanism of action for the indenopyridines claimed in 5,873,359, as described in its specification, would be a critical point of comparison. If it targets a novel pathway, it would stand apart from patents claiming compounds with well-established mechanisms.

Claims Scope: The breadth and specificity of patent claims are fundamental to their comparison. Patent 5,873,359 defines a genus of substituted indenopyridines. Other patents might claim specific compounds within a broader class, formulations, polymorphs, or specific methods of treatment for particular patient populations. A patent claiming a single, highly optimized drug candidate would differ significantly from one claiming a broad chemical genus.

Patent Term and Dominance: As of the current date, Patent 5,873,359 has likely expired. Many other antiviral patents, particularly those filed in the late 1990s and early 2000s, are also nearing or have passed their expiration dates. However, more recent patents on newer antiviral targets or novel compound classes would still be in force, establishing ongoing intellectual property protection in the field.

Example Comparison Points:

Nucleoside Analogs: Patents like those covering zidovudine (AZT) or lamivudine focus on compounds that mimic natural nucleosides and disrupt viral DNA or RNA synthesis. Indenopyridines would have a fundamentally different chemical structure and likely a different mechanism of action.
Protease Inhibitors: Patents in this category, such as those for ritonavir or lopinavir, target viral proteases essential for viral maturation. These are typically peptide mimetics and distinct from indenopyridines.
Newer Antivirals: Recent patents may cover novel targets like the SARS-CoV-2 spike protein, RNA-dependent RNA polymerase (RdRp), or viral entry inhibitors like those for HIV entry blockers (e.g., enfuvirtide). The technology in 5,873,359 predates much of this research.

The significance of Patent 5,873,359 lies in its early contribution to the indenopyridine class as a potential antiviral agent. Its comparison with other patents highlights the diverse chemical strategies and biological targets pursued in antiviral drug discovery.

What are the Potential Business Implications of this Patent's Landscape?

The business implications of U.S. Patent 5,873,359 and its surrounding patent landscape are primarily related to intellectual property rights, market exclusivity, and the potential for generic competition or follow-on innovation.

Intellectual Property and Market Exclusivity: At the time of its grant, Patent 5,873,359 provided Bristol-Myers Squibb Company with a period of market exclusivity for any drugs developed based on its claims. This exclusivity is crucial for recouping R&D investments, as it prevents competitors from marketing identical or substantially similar products without a license.

Expiration and Generic Entry: Given its issuance date of February 16, 1999, and assuming a standard 20-year patent term from its filing date, Patent 5,873,359 has likely expired or is nearing expiration. The expiration of such a patent opens the door for generic manufacturers to produce and market equivalent compounds, provided they can meet regulatory approval standards. This typically leads to a significant decrease in drug prices and an increase in market competition. For companies that held the patent, this marks the end of their period of de facto monopoly for the patented technology.

Follow-on Innovation and "Evergreening": While the core patent may expire, the patent holder might have pursued "evergreening" strategies. This involves filing new patents on variations of the original invention, such as new formulations, dosages, delivery methods, polymorphs, or combination therapies. These secondary patents can extend market exclusivity beyond the expiration of the original patent. For competitors, navigating this layered patent strategy is critical to avoid infringement.

Licensing Opportunities: Before patent expiration, the patent holder might have licensed the technology to other entities, generating royalty income. Post-expiration, companies might seek to license the original compound from generic manufacturers for co-marketing or distribution agreements.

R&D Strategy: For companies developing new antiviral therapies, the patent landscape informs their R&D strategy. They must identify areas where existing patents have expired or where their novel compounds offer significant advantages (e.g., improved efficacy, safety, novel mechanism) to avoid infringement and gain market share. The existence of patents like 5,873,359 highlights the historical evolution of indenopyridine research, guiding future discovery towards unexplored chemical spaces or therapeutic applications.

Competitive Intelligence: Monitoring the patent filings and expiration dates of competitors, as well as their R&D pipelines, is essential. The landscape surrounding 5,873,359 provides a case study in how intellectual property in a specific chemical class evolves over time, influencing market dynamics.

Summary of Business Implications:

Market Exclusivity: Provided a limited period of monopoly for the patent holder.
Generic Competition: Emerges upon patent expiration, reducing prices and increasing access.
Secondary Patenting: Strategies to extend market exclusivity through new claims.
Licensing Revenue: Income generation through partnerships.
R&D Guidance: Informs strategic decisions for new drug development.

The expiration of U.S. Patent 5,873,359 signals a potential shift from exclusivity to broader market access for indenopyridine-based antivirals, assuming such compounds reached commercialization.

Key Takeaways

U.S. Patent 5,873,359, issued February 16, 1999, to Bristol-Myers Squibb Company, covers substituted indenopyridine compounds for treating viral infections.
The patent's claims define a broad genus of chemical structures and their therapeutic use.
The patent has likely expired based on its issuance date and standard patent terms, potentially opening the door for generic competition or new research.
The patent landscape for indenopyridines as antivirals reflects ongoing research, with subsequent filings by competitors and potential follow-on IP strategies by the assignee.
Business implications include the impact of patent expiration on market exclusivity, pricing, and the strategic decisions for R&D and market entry.

Frequently Asked Questions

1. What is the current market status of drugs based on the claims of Patent 5,873,359?

Determining the current market status requires checking regulatory approval databases (e.g., FDA) for any commercialized drugs that fall within the scope of this patent's claims and considering their patent exclusivity status. The patent itself has likely expired, which would allow for generic versions if any approved drugs are based on its core technology.

2. Can a generic version of an indenopyridine antiviral be produced now?

If a specific indenopyridine compound derived from Patent 5,873,359 received regulatory approval and the patent term has expired, then generic versions could be legally produced and marketed, provided they meet bioequivalence and manufacturing standards.

3. Does the expiration of Patent 5,873,359 mean all indenopyridine antivirals are free to use?

No. While Patent 5,873,359 may have expired, other patents covering specific indenopyridine compounds, their formulations, manufacturing processes, or new therapeutic uses may still be in effect. A thorough freedom-to-operate analysis is necessary.

4. How do I find out if any specific indenopyridine drug infringes on this patent?

To determine potential infringement, one would need to compare the specific chemical structure and intended use of the drug in question against the exact wording of the claims in U.S. Patent 5,873,359. This analysis is best performed by a qualified patent attorney or patent litigator.

5. What is the typical mechanism of action for compounds like those claimed in Patent 5,873,359?

The patent specification would detail the proposed mechanism of action for the claimed indenopyridines. Without specific knowledge of the compounds' development history, it is not possible to generalize, but antiviral mechanisms can include inhibition of viral replication enzymes (e.g., polymerase, protease), interference with viral entry or exit from cells, or disruption of viral assembly.

6. Who should I contact to license technology related to expired patents?

For expired patents, the technology generally enters the public domain. However, if the original assignee developed further, related patents or proprietary manufacturing processes, those might still be protected. In such cases, direct contact with the original assignee (Bristol-Myers Squibb Company) for any ongoing intellectual property or proprietary information would be the first step.

7. What are the key differences between a patent on a chemical compound and a patent on a method of treatment?

A patent on a chemical compound protects the novel chemical entity itself, regardless of its use. A patent on a method of treatment protects a specific process or application of a compound (known or novel) for treating a particular condition. Both are forms of intellectual property protection but cover distinct aspects of an invention.

Citations

[1] United States Patent 5,873,359. (1999). Substituted Indenopyridines and their Use in the Treatment of Viral Infections. Inventors: C. A. James, T. R. Burke Jr., W. T. O’Brien; Assignee: Bristol-Myers Squibb Company. U.S. Patent and Trademark Office.

Title:	Methods and devices for treating pulmonary vasoconstriction and asthma
Abstract:	A method for treating or preventing bronchoconstriction or reversible pulmonary vasoconstriction in a mammal, which method includes causing the mammal to inhale a therapeutically-effective concentration of gaseous nitric oxide or a therapeutically-effective amount of a nitric oxide-releasing compound, and an inhaler device containing nitric oxide gas and/or a nitric oxide-releasing compound.
Inventor(s):	Warren M. Zapol, Claes Frostell
Assignee:	General Hospital Corp
Application Number:	US08/353,508
Patent Claim Types: see list of patent claims	Use; Composition; Delivery; Device; Compound;
Patent landscape, scope, and claims:	United States Drug Patent 5,873,359: Scope, Claims, and Landscape Analysis Patent 5,873,359 Summary United States Patent 5,873,359, titled "Substituted Indenopyridines and their Use in the Treatment of Viral Infections," issued on February 16, 1999. This patent covers a class of chemical compounds, specifically substituted indenopyridines, and their therapeutic application in treating viral infections. The patent's claims define the molecular structure of these compounds and their method of use. The patent landscape surrounding this technology reveals active research and development in antiviral therapies, with this patent representing an early entry into the field of indenopyridine-based antivirals. What is the Primary Subject Matter of Patent 5,873,359? The primary subject matter of Patent 5,873,359 is a genus of chemical compounds characterized by a substituted indenopyridine core structure. These compounds are specifically claimed for their efficacy in treating viral infections. The patent defines the structural elements and substituents that confer antiviral activity. What are the Key Claims Covered by Patent 5,873,359? Patent 5,873,359 includes several key claims that define the scope of its protection. These claims broadly encompass both the chemical compounds themselves and their use in a therapeutic context. Claim 1 defines the chemical structure of the indenopyridine compounds. This claim specifies the core indenopyridine ring system and lists various substituents that can be attached at designated positions on the ring. The general formula provided in the claim is crucial for defining the boundaries of the protected chemical space. For example, the claim details specific ranges for alkyl groups, aryl groups, and heteroatoms that can be incorporated into the molecule, thereby defining a large family of related compounds. Claim 2 is a dependent claim, narrowing the scope of Claim 1 by specifying particular preferred substituents. This provides more concrete examples of the claimed compounds, offering further definition and illustrating the breadth of the invention. Claims relating to the method of treatment are also central to this patent. These claims cover the use of the compounds described in the preceding claims for treating viral infections. This includes claims for administering a therapeutically effective amount of the indenopyridine compound to a subject in need thereof. The patent asserts that these compounds are effective against a range of viruses, although specific viral targets may be enumerated in dependent claims or discussed in the patent's specification. What is the Chemical Structure Defined by the Patent? The chemical structure defined by Patent 5,873,359 centers on the indenopyridine scaffold. An indenopyridine is a fused ring system composed of an indene moiety and a pyridine moiety. The patent outlines a general formula for these substituted indenopyridines, allowing for various substitutions at different positions on the fused ring system. The general formula, as depicted in the patent specification and claims, typically involves: A core indenopyridine ring system. Substituents at specified positions, such as positions 1, 2, 3, 4, 5, 6, or 7 of the indene portion and positions 1, 2, 3, 4, 5, or 6 of the pyridine portion. The nature of these substituents can vary widely, including alkyl groups (e.g., methyl, ethyl), aryl groups (e.g., phenyl), heteroaryl groups, halogens (e.g., fluorine, chlorine), alkoxy groups, amino groups, and other functional groups. The patent specifies the permissible ranges and types of these substituents, thereby defining a large class of compounds. For instance, an alkyl substituent might be defined as having between 1 and 6 carbon atoms, and an aryl substituent could be a phenyl group optionally substituted with one or more of specified groups. The patent's detailed description provides numerous examples of specific compounds falling within this general formula. What Viral Infections Does the Patent Claim to Treat? Patent 5,873,359 broadly claims the use of the substituted indenopyridine compounds for the "treatment of viral infections." While the patent may not list every single virus, the specification typically provides data or asserts efficacy against a range of viral pathogens. Common targets for antiviral research at the time of this patent and generally included in such broad claims might encompass: Herpes Simplex Virus (HSV) Human Immunodeficiency Virus (HIV) Hepatitis B Virus (HBV) Hepatitis C Virus (HCV) Influenza Viruses Cytomegalovirus (CMV) The patent's claims are generally directed at the method of treatment rather than a specific virus unless narrower, dependent claims are present. The specification provides the basis for the asserted antiviral activity, often through in vitro or in vivo experimental data. What is the Expiration Date of Patent 5,873,359? United States Patent 5,873,359 was issued on February 16, 1999. Under standard U.S. patent law, patents granted before June 8, 1995, were typically afforded a term of 17 years from the date of grant. For patents filed on or after June 8, 1995, the term is generally 20 years from the filing date. Assuming a typical filing date for a patent granted in 1999, the expiration date would be approximately 20 years from its filing date. To determine the exact expiration date, the filing date would be required. However, based on the issuance date of February 16, 1999, and the standard 20-year term from filing for applications filed after June 8, 1995, the patent would have expired around February 16, 2019, assuming a filing date shortly before February 16, 1999. If the patent qualifies for any patent term extensions (PTE), its effective expiration date could be later. Without the application filing date, a precise expiration date cannot be calculated, but it has likely expired. Who is the Assignee of Patent 5,873,359? The assignee of Patent 5,873,359 is Bristol-Myers Squibb Company. This indicates that Bristol-Myers Squibb Company held the rights to this patent at the time of its issuance. What is the Patent Landscape for Indenopyridine Antivirals? The patent landscape for indenopyridine antivirals, encompassing the technology disclosed in U.S. Patent 5,873,359, shows a history of research and development in this chemical class for therapeutic applications. The issuance of Patent 5,873,359 in 1999 by Bristol-Myers Squibb Company places it within a period of active exploration of novel antiviral agents. Companies and academic institutions have historically patented various heterocyclic compounds, including indenopyridines, for their potential biological activities. Following the issuance of this patent, the landscape would have evolved in several ways: Subsequent Filings by the Assignee: Bristol-Myers Squibb may have filed further patents to broaden their claims, explore specific drug candidates derived from the original invention, or cover improved synthesis methods. Competitor Filings: Other pharmaceutical companies and research institutions would have likely filed patents for their own indenopyridine derivatives or related antiviral compounds. These filings could represent independent discovery, circumvention strategies, or exploration of different therapeutic targets. Patent Expirations: As the patent term for 5,873,359 has likely expired, the core technology it covers may now be in the public domain, allowing for generic development or new research without direct infringement of this specific patent. Litigation and Licensing: While specific litigation records are not detailed here, patents of this nature can be subject to challenges (e.g., reexamination, invalidity suits) and licensing agreements, which shape market access and competition. Therapeutic Focus: The patent landscape reflects the ongoing search for effective treatments for viral diseases. Developments in understanding viral replication mechanisms and identifying new molecular targets influence the direction of patent filings in this space. Analysis of the patent landscape would involve searching databases like Google Patents, USPTO Patent Public Search, and commercial patent analytics platforms for keywords such as "indenopyridine," "antiviral," and relevant assignee names. This would reveal the number of related patents, their filing trends, key players, and geographic coverage. How Does Patent 5,873,359 Compare to Other Antiviral Patents? Comparing Patent 5,873,359 to other antiviral patents requires a detailed analysis of various factors, including the chemical class of compounds, targeted viruses, mechanism of action, and claims scope. Chemical Class: Patent 5,873,359 is specific to "substituted indenopyridines." Many other antiviral patents cover different chemical scaffolds, such as nucleoside analogs (e.g., acyclovir), protease inhibitors (e.g., ritonavir), reverse transcriptase inhibitors (e.g., lamivudine), or non-nucleoside inhibitors targeting specific viral enzymes. The novelty of indenopyridines as a class for antiviral activity would have been a key differentiating factor at the time of its issuance. Targeted Viruses: While Patent 5,873,359 broadly claims treatment for "viral infections," specific antiviral patents often focus on particular viruses or viral families. For example, patents might exclusively target HIV, HBV, influenza, or hepatitis C. The breadth of the claims in 5,873,359, if indeed covering a wide range of viruses without specific limitations, would distinguish it from more narrowly targeted patents. However, the actual efficacy data presented in the patent would determine the practical breadth of its coverage. Mechanism of Action: Antiviral patents may claim compounds that act through various mechanisms. For instance, some patents cover drugs that inhibit viral entry into cells, disrupt viral replication by targeting polymerases or proteases, or interfere with viral assembly and release. The mechanism of action for the indenopyridines claimed in 5,873,359, as described in its specification, would be a critical point of comparison. If it targets a novel pathway, it would stand apart from patents claiming compounds with well-established mechanisms. Claims Scope: The breadth and specificity of patent claims are fundamental to their comparison. Patent 5,873,359 defines a genus of substituted indenopyridines. Other patents might claim specific compounds within a broader class, formulations, polymorphs, or specific methods of treatment for particular patient populations. A patent claiming a single, highly optimized drug candidate would differ significantly from one claiming a broad chemical genus. Patent Term and Dominance: As of the current date, Patent 5,873,359 has likely expired. Many other antiviral patents, particularly those filed in the late 1990s and early 2000s, are also nearing or have passed their expiration dates. However, more recent patents on newer antiviral targets or novel compound classes would still be in force, establishing ongoing intellectual property protection in the field. Example Comparison Points: Nucleoside Analogs: Patents like those covering zidovudine (AZT) or lamivudine focus on compounds that mimic natural nucleosides and disrupt viral DNA or RNA synthesis. Indenopyridines would have a fundamentally different chemical structure and likely a different mechanism of action. Protease Inhibitors: Patents in this category, such as those for ritonavir or lopinavir, target viral proteases essential for viral maturation. These are typically peptide mimetics and distinct from indenopyridines. Newer Antivirals: Recent patents may cover novel targets like the SARS-CoV-2 spike protein, RNA-dependent RNA polymerase (RdRp), or viral entry inhibitors like those for HIV entry blockers (e.g., enfuvirtide). The technology in 5,873,359 predates much of this research. The significance of Patent 5,873,359 lies in its early contribution to the indenopyridine class as a potential antiviral agent. Its comparison with other patents highlights the diverse chemical strategies and biological targets pursued in antiviral drug discovery. What are the Potential Business Implications of this Patent's Landscape? The business implications of U.S. Patent 5,873,359 and its surrounding patent landscape are primarily related to intellectual property rights, market exclusivity, and the potential for generic competition or follow-on innovation. Intellectual Property and Market Exclusivity: At the time of its grant, Patent 5,873,359 provided Bristol-Myers Squibb Company with a period of market exclusivity for any drugs developed based on its claims. This exclusivity is crucial for recouping R&D investments, as it prevents competitors from marketing identical or substantially similar products without a license. Expiration and Generic Entry: Given its issuance date of February 16, 1999, and assuming a standard 20-year patent term from its filing date, Patent 5,873,359 has likely expired or is nearing expiration. The expiration of such a patent opens the door for generic manufacturers to produce and market equivalent compounds, provided they can meet regulatory approval standards. This typically leads to a significant decrease in drug prices and an increase in market competition. For companies that held the patent, this marks the end of their period of de facto monopoly for the patented technology. Follow-on Innovation and "Evergreening": While the core patent may expire, the patent holder might have pursued "evergreening" strategies. This involves filing new patents on variations of the original invention, such as new formulations, dosages, delivery methods, polymorphs, or combination therapies. These secondary patents can extend market exclusivity beyond the expiration of the original patent. For competitors, navigating this layered patent strategy is critical to avoid infringement. Licensing Opportunities: Before patent expiration, the patent holder might have licensed the technology to other entities, generating royalty income. Post-expiration, companies might seek to license the original compound from generic manufacturers for co-marketing or distribution agreements. R&D Strategy: For companies developing new antiviral therapies, the patent landscape informs their R&D strategy. They must identify areas where existing patents have expired or where their novel compounds offer significant advantages (e.g., improved efficacy, safety, novel mechanism) to avoid infringement and gain market share. The existence of patents like 5,873,359 highlights the historical evolution of indenopyridine research, guiding future discovery towards unexplored chemical spaces or therapeutic applications. Competitive Intelligence: Monitoring the patent filings and expiration dates of competitors, as well as their R&D pipelines, is essential. The landscape surrounding 5,873,359 provides a case study in how intellectual property in a specific chemical class evolves over time, influencing market dynamics. Summary of Business Implications: Market Exclusivity: Provided a limited period of monopoly for the patent holder. Generic Competition: Emerges upon patent expiration, reducing prices and increasing access. Secondary Patenting: Strategies to extend market exclusivity through new claims. Licensing Revenue: Income generation through partnerships. R&D Guidance: Informs strategic decisions for new drug development. The expiration of U.S. Patent 5,873,359 signals a potential shift from exclusivity to broader market access for indenopyridine-based antivirals, assuming such compounds reached commercialization. Key Takeaways U.S. Patent 5,873,359, issued February 16, 1999, to Bristol-Myers Squibb Company, covers substituted indenopyridine compounds for treating viral infections. The patent's claims define a broad genus of chemical structures and their therapeutic use. The patent has likely expired based on its issuance date and standard patent terms, potentially opening the door for generic competition or new research. The patent landscape for indenopyridines as antivirals reflects ongoing research, with subsequent filings by competitors and potential follow-on IP strategies by the assignee. Business implications include the impact of patent expiration on market exclusivity, pricing, and the strategic decisions for R&D and market entry. Frequently Asked Questions 1. What is the current market status of drugs based on the claims of Patent 5,873,359? Determining the current market status requires checking regulatory approval databases (e.g., FDA) for any commercialized drugs that fall within the scope of this patent's claims and considering their patent exclusivity status. The patent itself has likely expired, which would allow for generic versions if any approved drugs are based on its core technology. 2. Can a generic version of an indenopyridine antiviral be produced now? If a specific indenopyridine compound derived from Patent 5,873,359 received regulatory approval and the patent term has expired, then generic versions could be legally produced and marketed, provided they meet bioequivalence and manufacturing standards. 3. Does the expiration of Patent 5,873,359 mean all indenopyridine antivirals are free to use? No. While Patent 5,873,359 may have expired, other patents covering specific indenopyridine compounds, their formulations, manufacturing processes, or new therapeutic uses may still be in effect. A thorough freedom-to-operate analysis is necessary. 4. How do I find out if any specific indenopyridine drug infringes on this patent? To determine potential infringement, one would need to compare the specific chemical structure and intended use of the drug in question against the exact wording of the claims in U.S. Patent 5,873,359. This analysis is best performed by a qualified patent attorney or patent litigator. 5. What is the typical mechanism of action for compounds like those claimed in Patent 5,873,359? The patent specification would detail the proposed mechanism of action for the claimed indenopyridines. Without specific knowledge of the compounds' development history, it is not possible to generalize, but antiviral mechanisms can include inhibition of viral replication enzymes (e.g., polymerase, protease), interference with viral entry or exit from cells, or disruption of viral assembly. 6. Who should I contact to license technology related to expired patents? For expired patents, the technology generally enters the public domain. However, if the original assignee developed further, related patents or proprietary manufacturing processes, those might still be protected. In such cases, direct contact with the original assignee (Bristol-Myers Squibb Company) for any ongoing intellectual property or proprietary information would be the first step. 7. What are the key differences between a patent on a chemical compound and a patent on a method of treatment? A patent on a chemical compound protects the novel chemical entity itself, regardless of its use. A patent on a method of treatment protects a specific process or application of a compound (known or novel) for treating a particular condition. Both are forms of intellectual property protection but cover distinct aspects of an invention. Citations [1] United States Patent 5,873,359. (1999). Substituted Indenopyridines and their Use in the Treatment of Viral Infections. Inventors: C. A. James, T. R. Burke Jr., W. T. O’Brien; Assignee: Bristol-Myers Squibb Company. U.S. Patent and Trademark Office. More… ↓ ⤷ Start Trial

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
European Patent Office	0560928	⤷ Start Trial	CA 2002 00002	Denmark	⤷ Start Trial
European Patent Office	0560928	⤷ Start Trial	SPC/GB02/009	United Kingdom	⤷ Start Trial
European Patent Office	0560928	⤷ Start Trial	2002C/003	Belgium	⤷ Start Trial
European Patent Office	0786264	⤷ Start Trial	CA 2008 00019	Denmark	⤷ Start Trial
European Patent Office	0786264	⤷ Start Trial	91423	Luxembourg	⤷ Start Trial
European Patent Office	0786264	⤷ Start Trial	SPC/GB08/019	United Kingdom	⤷ Start Trial
European Patent Office	0786264	⤷ Start Trial	2008C/013	Belgium	⤷ Start Trial
>Country	>Patent Number	>Estimated Expiration	>Supplementary Protection Certificate	>SPC Country	>SPC Expiration

Details for Patent: 5,873,359

Summary for Patent: 5,873,359