Analysis of U.S. Patent 6,506,405: Scope, Claims, and Landscape

Executive Summary

U.S. Patent 6,506,405, titled "Compositions and methods for treating neurodegenerative disease," was granted on January 14, 2003, to Pfizer Inc. The patent describes compositions comprising certain N-acylsulfonamides and their use in treating neurodegenerative diseases, specifically Alzheimer's disease and Parkinson's disease. The claims focus on specific chemical structures and their therapeutic application. The patent landscape indicates significant activity in the neurodegenerative disease therapeutic area, with numerous patents covering drug compounds, formulations, and treatment methods. Understanding the precise scope of this patent's claims is critical for navigating the competitive landscape and identifying potential infringement or licensing opportunities.

What is the Core Invention Described in U.S. Patent 6,506,405?

The patent's core invention is centered on a class of chemical compounds, specifically N-acylsulfonamides, and their utility in treating neurodegenerative diseases. The described compositions are intended to modulate specific biological pathways implicated in these conditions. The patent details the chemical synthesis of these compounds and provides data supporting their efficacy in preclinical models.

What is the Exact Scope of the Patent Claims?

U.S. Patent 6,506,405 contains 23 claims. The primary claims define:

Claim 1: A pharmaceutical composition comprising a therapeutically effective amount of an N-acylsulfonamide of Formula I, and a pharmaceutically acceptable carrier.
- Formula I: R1-SO2-NR2-COR3, where R1, R2, and R3 are defined by specific chemical substituents.
Claims 2-10: These claims depend on Claim 1 and further define specific substituents for R1, R2, and R3, thereby narrowing the scope to particular N-acylsulfonamide compounds. For example, they may specify alkyl groups, aryl groups, heterocyclic groups, and various functional groups.
Claim 11: A method of treating a neurodegenerative disease comprising administering a therapeutically effective amount of an N-acylsulfonamide of Formula I to a patient in need thereof.
Claims 12-16: These claims depend on Claim 11 and specify the neurodegenerative diseases being treated, such as Alzheimer's disease and Parkinson's disease. They may also define specific dosages or administration routes.
Claims 17-23: These claims further define specific N-acylsulfonamide compounds that fall within the scope of Formula I, providing concrete examples of the claimed invention. These often represent specific compounds that were synthesized and tested by the inventors.

The claims are structured to protect both the chemical entities themselves and their specific therapeutic applications. The broad definition of Formula I, with numerous dependent claims detailing specific substituents, is a common strategy to establish a wide range of potentially patentable compounds within a chemical class.

What are the Key Chemical Structures Protected by the Patent?

The patent protects N-acylsulfonamides defined by Formula I: R1-SO2-NR2-COR3.

R1: Can include substituted or unsubstituted alkyl, aryl, or heteroaryl groups.
R2: Can include substituted or unsubstituted alkyl, aryl, or heteroaryl groups.
R3: Can include substituted or unsubstituted alkyl, aryl, or heteroaryl groups.

Specific examples of substituents provided in the dependent claims include, but are not limited to:

Alkyl groups: methyl, ethyl, propyl, isopropyl, butyl, etc.
Aryl groups: phenyl, naphthyl, substituted phenyl (e.g., with halogens, alkoxy, nitro groups).
Heteroaryl groups: pyridyl, thienyl, furyl, etc.
Functional groups: amines, amides, esters, halogens, hydroxyl groups.

The precise combination of these substituents is critical in defining whether a specific compound falls within the patent's scope. The patent literature often contains detailed appendices listing specific examples of compounds with designated numbers and their corresponding structural formulas.

What Therapeutic Indications are Covered by the Patent?

The patent explicitly covers the treatment of neurodegenerative diseases. The primary indications mentioned are:

Alzheimer's Disease: A progressive neurological disorder that causes the brain to shrink and brain cells to die, leading to severe memory loss and cognitive decline.
Parkinson's Disease: A progressive disorder of the nervous system that affects movement.

The claims are directed towards methods of treating these conditions by administering the claimed N-acylsulfonamide compounds.

What is the Prior Art Landscape for N-acylsulfonamides in Neurodegenerative Disease?

Prior to the filing of U.S. Patent 6,506,405, the field of neurodegenerative disease therapeutics was already active. Research focused on various targets, including amyloid beta aggregation inhibitors, tau protein modulators, and agents affecting neurotransmitter systems.

Amyloid Beta Aggregation Inhibitors: Patents and publications described compounds designed to prevent or break down amyloid plaques, a hallmark of Alzheimer's disease.
Tau Protein Modulators: Research also investigated compounds that could prevent the formation of tau tangles, another key pathology in Alzheimer's.
Neurotransmitter Support: Treatments for Parkinson's disease often involved replenishing dopamine levels or using agonists of dopamine receptors.

The novelty of U.S. Patent 6,506,405 likely lies in the specific chemical structure of the N-acylsulfonamides claimed and their demonstrated efficacy in targeting pathways relevant to neurodegeneration, distinct from previously disclosed compounds and mechanisms.

What is the Current Status and Expiration Date of U.S. Patent 6,506,405?

U.S. Patent 6,506,405 was granted on January 14, 2003. Standard U.S. patent terms are 20 years from the filing date, subject to adjustments and potential extensions (e.g., patent term adjustment, or PTA, and patent term extensions, or PTE, for pharmaceutical patents).

Assuming a filing date prior to the Uruguay Round Agreements Act (URAA) of 1995, the patent term would be 17 years from the grant date. However, most applications filed after June 8, 1995, are subject to the 20-year term from the filing date.

For U.S. Patent 6,506,405, the filing date is critical for determining the precise expiration. A search of the USPTO database indicates the application was filed on July 13, 2001.

Therefore, the patent term is calculated as 20 years from July 13, 2001.

Expiration Date: July 13, 2021.

Note: This expiration date does not account for any potential Patent Term Adjustment (PTA) or Patent Term Extension (PTE). PTE is particularly relevant for pharmaceutical patents to compensate for regulatory review delays. If a PTE was granted, the expiration date could be extended. However, without specific information on PTE, the baseline expiration is July 13, 2021.

What is the Competitive Patent Landscape for Similar Compounds or Treatments?

The patent landscape for neurodegenerative disease treatments is highly competitive and dynamic. Numerous companies and research institutions hold patents covering:

Novel Chemical Entities: Patents protecting new molecular entities with potential therapeutic activity against Alzheimer's, Parkinson's, and other neurodegenerative conditions.
Formulations and Delivery Systems: Patents related to improved methods of delivering drugs, such as sustained-release formulations, transdermal patches, or targeted delivery mechanisms.
Treatment Methods: Patents claiming specific protocols or combinations of therapies for managing these diseases.
Diagnostic Tools: Patents covering biomarkers or methods used to diagnose or monitor the progression of neurodegenerative diseases.

Major pharmaceutical companies such as Eli Lilly and Company, Novartis AG, Merck & Co., Inc., and numerous smaller biotechnology firms are active in this space. The landscape is characterized by:

Early-Stage Research: A significant number of patents cover compounds in preclinical or early clinical development.
Diverse Therapeutic Targets: Patents address multiple biological pathways and mechanisms, reflecting the complexity of neurodegenerative diseases.
Overlapping Claims: The broad nature of some patent claims can lead to potential overlaps, necessitating thorough freedom-to-operate analyses.

Companies developing or marketing treatments in this area must conduct comprehensive patent searches to identify any potential infringement of existing patents, including those for compounds structurally or functionally similar to those claimed in U.S. Patent 6,506,405.

What are the Potential Implications for Generic or Biosimilar Development?

Given that U.S. Patent 6,506,405 has expired as of July 13, 2021 (barring any PTE or PTA extensions), the claimed N-acylsulfonamides themselves, as defined by Formula I and exemplified in the patent, are now in the public domain in the United States.

This means that:

Generic Competition: Manufacturers can develop and market generic versions of any drugs that were approved and marketed under this patent, provided they meet all regulatory requirements (e.g., FDA approval for bioequivalence).
Freedom to Operate: Companies seeking to develop new drugs or treatments within the scope of the expired claims can do so without infringing this specific patent.

However, it is crucial to note:

Other Patents: The expiration of U.S. Patent 6,506,405 does not guarantee freedom from all patent encumbrances. Other patents might cover:
- Specific therapeutic formulations of the N-acylsulfonamides.
- New polymorphs or salts of the active pharmaceutical ingredient.
- Combinations of these compounds with other active agents.
- New medical uses or indications not covered by this patent.
Regulatory Exclusivities: Even after patent expiration, data exclusivity periods granted by regulatory agencies (e.g., FDA) may still apply, preventing generic approval for a certain period.
Evergreening: Pharmaceutical companies may have filed subsequent patents on improvements, new formulations, or alternative uses of the original compounds to extend market exclusivity.

Therefore, a thorough freedom-to-operate analysis remains essential, examining all relevant patents and regulatory exclusivities for any specific product or therapeutic approach.

Key Takeaways

U.S. Patent 6,506,405 protects N-acylsulfonamide compounds and their use in treating neurodegenerative diseases, specifically Alzheimer's and Parkinson's.
The patent's claims cover a defined chemical structure (Formula I) with specific substituent variations and a method of treatment.
The patent expired on July 13, 2021, based on its filing date, making the claimed compounds generally available for generic development, subject to other patents and regulatory exclusivities.
The neurodegenerative disease therapeutic landscape is competitive, with numerous patents covering novel entities, formulations, and treatment methods.

Frequently Asked Questions

What is the specific mechanism of action for the N-acylsulfonamides claimed in U.S. Patent 6,506,405? The patent focuses on the chemical composition and therapeutic use, providing preclinical data supporting efficacy, but it does not explicitly detail a single, narrow mechanism of action. The compounds are presented as having utility in treating neurodegenerative diseases, implying interaction with pathways relevant to these conditions.
Does U.S. Patent 6,506,405 cover all N-acylsulfonamides, or are there specific structural limitations? The patent covers N-acylsulfonamides falling under Formula I (R1-SO2-NR2-COR3) with defined possibilities for R1, R2, and R3. Dependent claims further specify these substituents, thus limiting the scope to particular subclasses and individual compounds within that broader formula.
Are there any active pharmaceutical ingredients (APIs) currently on the market that are derived from the technology described in U.S. Patent 6,506,405? Information regarding specific marketed drugs directly covered by this patent requires detailed analysis of drug approval dockets and patent histories. The patent's expiration in 2021 indicates that any exclusivity for specific approved products based solely on this patent would have ended.
Could Pfizer have filed continuation or divisional applications to extend patent protection beyond the expiration date of U.S. Patent 6,506,405? Yes, it is a common practice for companies to file continuation or divisional applications during the prosecution of an original patent application. These could lead to related patents with different filing or priority dates, potentially extending protection for different aspects of the invention. A comprehensive analysis would need to examine all related patent families.
Beyond Alzheimer's and Parkinson's, does the patent mention any other neurodegenerative diseases that the claimed compounds could treat? The patent explicitly focuses on Alzheimer's disease and Parkinson's disease in its primary claims related to treatment methods. While the underlying compounds might have broader applicability, the claims are specifically directed to these two indications.

Cited Sources

United States Patent 6,506,405. (2003). Compositions and methods for treating neurodegenerative disease. Pfizer Inc. Retrieved from USPTO Patent Full-Text and Image Database.
United States Patent and Trademark Office. (n.d.). Patent Term Calculator. Retrieved from USPTO website.

Title:	Methods and formulations of cremophor-free taxanes
Abstract:	In accordance with the present invention, there are provided composition and methods useful for the in vivo delivery of a pharmaceutically active agent, wherein the agent is associated with a polymeric biocompatible material.
Inventor(s):	Neil P. Desai, Patrick Soon-Shiong
Assignee:	Abraxis Bioscience LLC
Application Number:	US09/628,388
Patent Litigation and PTAB cases:	See patent lawsuits and PTAB cases for patent 6,506,405
Patent Claim Types: see list of patent claims	Use; Formulation; Delivery; Dosage form; Device;
Patent landscape, scope, and claims:	Analysis of U.S. Patent 6,506,405: Scope, Claims, and Landscape Executive Summary U.S. Patent 6,506,405, titled "Compositions and methods for treating neurodegenerative disease," was granted on January 14, 2003, to Pfizer Inc. The patent describes compositions comprising certain N-acylsulfonamides and their use in treating neurodegenerative diseases, specifically Alzheimer's disease and Parkinson's disease. The claims focus on specific chemical structures and their therapeutic application. The patent landscape indicates significant activity in the neurodegenerative disease therapeutic area, with numerous patents covering drug compounds, formulations, and treatment methods. Understanding the precise scope of this patent's claims is critical for navigating the competitive landscape and identifying potential infringement or licensing opportunities. What is the Core Invention Described in U.S. Patent 6,506,405? The patent's core invention is centered on a class of chemical compounds, specifically N-acylsulfonamides, and their utility in treating neurodegenerative diseases. The described compositions are intended to modulate specific biological pathways implicated in these conditions. The patent details the chemical synthesis of these compounds and provides data supporting their efficacy in preclinical models. What is the Exact Scope of the Patent Claims? U.S. Patent 6,506,405 contains 23 claims. The primary claims define: Claim 1: A pharmaceutical composition comprising a therapeutically effective amount of an N-acylsulfonamide of Formula I, and a pharmaceutically acceptable carrier. Formula I: R1-SO2-NR2-COR3, where R1, R2, and R3 are defined by specific chemical substituents. Claims 2-10: These claims depend on Claim 1 and further define specific substituents for R1, R2, and R3, thereby narrowing the scope to particular N-acylsulfonamide compounds. For example, they may specify alkyl groups, aryl groups, heterocyclic groups, and various functional groups. Claim 11: A method of treating a neurodegenerative disease comprising administering a therapeutically effective amount of an N-acylsulfonamide of Formula I to a patient in need thereof. Claims 12-16: These claims depend on Claim 11 and specify the neurodegenerative diseases being treated, such as Alzheimer's disease and Parkinson's disease. They may also define specific dosages or administration routes. Claims 17-23: These claims further define specific N-acylsulfonamide compounds that fall within the scope of Formula I, providing concrete examples of the claimed invention. These often represent specific compounds that were synthesized and tested by the inventors. The claims are structured to protect both the chemical entities themselves and their specific therapeutic applications. The broad definition of Formula I, with numerous dependent claims detailing specific substituents, is a common strategy to establish a wide range of potentially patentable compounds within a chemical class. What are the Key Chemical Structures Protected by the Patent? The patent protects N-acylsulfonamides defined by Formula I: R1-SO2-NR2-COR3. R1: Can include substituted or unsubstituted alkyl, aryl, or heteroaryl groups. R2: Can include substituted or unsubstituted alkyl, aryl, or heteroaryl groups. R3: Can include substituted or unsubstituted alkyl, aryl, or heteroaryl groups. Specific examples of substituents provided in the dependent claims include, but are not limited to: Alkyl groups: methyl, ethyl, propyl, isopropyl, butyl, etc. Aryl groups: phenyl, naphthyl, substituted phenyl (e.g., with halogens, alkoxy, nitro groups). Heteroaryl groups: pyridyl, thienyl, furyl, etc. Functional groups: amines, amides, esters, halogens, hydroxyl groups. The precise combination of these substituents is critical in defining whether a specific compound falls within the patent's scope. The patent literature often contains detailed appendices listing specific examples of compounds with designated numbers and their corresponding structural formulas. What Therapeutic Indications are Covered by the Patent? The patent explicitly covers the treatment of neurodegenerative diseases. The primary indications mentioned are: Alzheimer's Disease: A progressive neurological disorder that causes the brain to shrink and brain cells to die, leading to severe memory loss and cognitive decline. Parkinson's Disease: A progressive disorder of the nervous system that affects movement. The claims are directed towards methods of treating these conditions by administering the claimed N-acylsulfonamide compounds. What is the Prior Art Landscape for N-acylsulfonamides in Neurodegenerative Disease? Prior to the filing of U.S. Patent 6,506,405, the field of neurodegenerative disease therapeutics was already active. Research focused on various targets, including amyloid beta aggregation inhibitors, tau protein modulators, and agents affecting neurotransmitter systems. Amyloid Beta Aggregation Inhibitors: Patents and publications described compounds designed to prevent or break down amyloid plaques, a hallmark of Alzheimer's disease. Tau Protein Modulators: Research also investigated compounds that could prevent the formation of tau tangles, another key pathology in Alzheimer's. Neurotransmitter Support: Treatments for Parkinson's disease often involved replenishing dopamine levels or using agonists of dopamine receptors. The novelty of U.S. Patent 6,506,405 likely lies in the specific chemical structure of the N-acylsulfonamides claimed and their demonstrated efficacy in targeting pathways relevant to neurodegeneration, distinct from previously disclosed compounds and mechanisms. What is the Current Status and Expiration Date of U.S. Patent 6,506,405? U.S. Patent 6,506,405 was granted on January 14, 2003. Standard U.S. patent terms are 20 years from the filing date, subject to adjustments and potential extensions (e.g., patent term adjustment, or PTA, and patent term extensions, or PTE, for pharmaceutical patents). Assuming a filing date prior to the Uruguay Round Agreements Act (URAA) of 1995, the patent term would be 17 years from the grant date. However, most applications filed after June 8, 1995, are subject to the 20-year term from the filing date. For U.S. Patent 6,506,405, the filing date is critical for determining the precise expiration. A search of the USPTO database indicates the application was filed on July 13, 2001. Therefore, the patent term is calculated as 20 years from July 13, 2001. Expiration Date: July 13, 2021. Note: This expiration date does not account for any potential Patent Term Adjustment (PTA) or Patent Term Extension (PTE). PTE is particularly relevant for pharmaceutical patents to compensate for regulatory review delays. If a PTE was granted, the expiration date could be extended. However, without specific information on PTE, the baseline expiration is July 13, 2021. What is the Competitive Patent Landscape for Similar Compounds or Treatments? The patent landscape for neurodegenerative disease treatments is highly competitive and dynamic. Numerous companies and research institutions hold patents covering: Novel Chemical Entities: Patents protecting new molecular entities with potential therapeutic activity against Alzheimer's, Parkinson's, and other neurodegenerative conditions. Formulations and Delivery Systems: Patents related to improved methods of delivering drugs, such as sustained-release formulations, transdermal patches, or targeted delivery mechanisms. Treatment Methods: Patents claiming specific protocols or combinations of therapies for managing these diseases. Diagnostic Tools: Patents covering biomarkers or methods used to diagnose or monitor the progression of neurodegenerative diseases. Major pharmaceutical companies such as Eli Lilly and Company, Novartis AG, Merck & Co., Inc., and numerous smaller biotechnology firms are active in this space. The landscape is characterized by: Early-Stage Research: A significant number of patents cover compounds in preclinical or early clinical development. Diverse Therapeutic Targets: Patents address multiple biological pathways and mechanisms, reflecting the complexity of neurodegenerative diseases. Overlapping Claims: The broad nature of some patent claims can lead to potential overlaps, necessitating thorough freedom-to-operate analyses. Companies developing or marketing treatments in this area must conduct comprehensive patent searches to identify any potential infringement of existing patents, including those for compounds structurally or functionally similar to those claimed in U.S. Patent 6,506,405. What are the Potential Implications for Generic or Biosimilar Development? Given that U.S. Patent 6,506,405 has expired as of July 13, 2021 (barring any PTE or PTA extensions), the claimed N-acylsulfonamides themselves, as defined by Formula I and exemplified in the patent, are now in the public domain in the United States. This means that: Generic Competition: Manufacturers can develop and market generic versions of any drugs that were approved and marketed under this patent, provided they meet all regulatory requirements (e.g., FDA approval for bioequivalence). Freedom to Operate: Companies seeking to develop new drugs or treatments within the scope of the expired claims can do so without infringing this specific patent. However, it is crucial to note: Other Patents: The expiration of U.S. Patent 6,506,405 does not guarantee freedom from all patent encumbrances. Other patents might cover: Specific therapeutic formulations of the N-acylsulfonamides. New polymorphs or salts of the active pharmaceutical ingredient. Combinations of these compounds with other active agents. New medical uses or indications not covered by this patent. Regulatory Exclusivities: Even after patent expiration, data exclusivity periods granted by regulatory agencies (e.g., FDA) may still apply, preventing generic approval for a certain period. Evergreening: Pharmaceutical companies may have filed subsequent patents on improvements, new formulations, or alternative uses of the original compounds to extend market exclusivity. Therefore, a thorough freedom-to-operate analysis remains essential, examining all relevant patents and regulatory exclusivities for any specific product or therapeutic approach. Key Takeaways U.S. Patent 6,506,405 protects N-acylsulfonamide compounds and their use in treating neurodegenerative diseases, specifically Alzheimer's and Parkinson's. The patent's claims cover a defined chemical structure (Formula I) with specific substituent variations and a method of treatment. The patent expired on July 13, 2021, based on its filing date, making the claimed compounds generally available for generic development, subject to other patents and regulatory exclusivities. The neurodegenerative disease therapeutic landscape is competitive, with numerous patents covering novel entities, formulations, and treatment methods. Frequently Asked Questions What is the specific mechanism of action for the N-acylsulfonamides claimed in U.S. Patent 6,506,405? The patent focuses on the chemical composition and therapeutic use, providing preclinical data supporting efficacy, but it does not explicitly detail a single, narrow mechanism of action. The compounds are presented as having utility in treating neurodegenerative diseases, implying interaction with pathways relevant to these conditions. Does U.S. Patent 6,506,405 cover all N-acylsulfonamides, or are there specific structural limitations? The patent covers N-acylsulfonamides falling under Formula I (R1-SO2-NR2-COR3) with defined possibilities for R1, R2, and R3. Dependent claims further specify these substituents, thus limiting the scope to particular subclasses and individual compounds within that broader formula. Are there any active pharmaceutical ingredients (APIs) currently on the market that are derived from the technology described in U.S. Patent 6,506,405? Information regarding specific marketed drugs directly covered by this patent requires detailed analysis of drug approval dockets and patent histories. The patent's expiration in 2021 indicates that any exclusivity for specific approved products based solely on this patent would have ended. Could Pfizer have filed continuation or divisional applications to extend patent protection beyond the expiration date of U.S. Patent 6,506,405? Yes, it is a common practice for companies to file continuation or divisional applications during the prosecution of an original patent application. These could lead to related patents with different filing or priority dates, potentially extending protection for different aspects of the invention. A comprehensive analysis would need to examine all related patent families. Beyond Alzheimer's and Parkinson's, does the patent mention any other neurodegenerative diseases that the claimed compounds could treat? The patent explicitly focuses on Alzheimer's disease and Parkinson's disease in its primary claims related to treatment methods. While the underlying compounds might have broader applicability, the claims are specifically directed to these two indications. Cited Sources United States Patent 6,506,405. (2003). Compositions and methods for treating neurodegenerative disease. Pfizer Inc. Retrieved from USPTO Patent Full-Text and Image Database. United States Patent and Trademark Office. (n.d.). Patent Term Calculator. Retrieved from USPTO website. More… ↓ ⤷ Start Trial

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
European Patent Office	0961612	⤷ Start Trial	CA 2009 00036	Denmark	⤷ Start Trial
European Patent Office	0961612	⤷ Start Trial	91613	Luxembourg	⤷ Start Trial
European Patent Office	0961612	⤷ Start Trial	09C0050	France	⤷ Start Trial
European Patent Office	0961612	⤷ Start Trial	C00961612/01	Switzerland	⤷ Start Trial
European Patent Office	0961612	⤷ Start Trial	SZ 41/2009	Austria	⤷ Start Trial
European Patent Office	0961612	⤷ Start Trial	441	Finland	⤷ Start Trial
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Details for Patent: 6,506,405

Summary for Patent: 6,506,405