United States Drug Patent 5,457,895: Scope, Claims, and Landscape Analysis

This report analyzes United States Patent 5,457,895, detailing its claims, scope, and the surrounding patent landscape. The patent, issued on October 17, 1995, to Merck & Co., Inc., covers certain substituted pyrazolo[3,4-b]pyridines and their use as intermediates in the synthesis of phosphodiesterase inhibitors.

What is the Core Innovation of Patent 5,457,895?

Patent 5,457,895 protects a specific class of chemical compounds: substituted pyrazolo[3,4-b]pyridines. These compounds are defined by a precise structural formula and substituents. The patent also claims the use of these compounds as intermediates in the manufacture of phosphodiesterase (PDE) inhibitors. PDE inhibitors are a class of drugs used to treat various conditions, including erectile dysfunction, pulmonary hypertension, and asthma. The innovation lies in identifying these particular pyrazolo[3,4-b]pyridine structures as effective precursors for synthesizing PDE inhibitors, thereby streamlining or enabling the production of these therapeutic agents.

What Are the Key Claims in Patent 5,457,895?

The patent’s claims are directed towards both the chemical compounds themselves and their specific application.

Claim 1: This is the primary composition of matter claim. It defines a genus of substituted pyrazolo[3,4-b]pyridines. The core structure is a pyrazolo[3,4-b]pyridine ring system. Specific substituents are defined at positions 1, 3, 4, and 6 of this ring system. For example, the substituent at position 1 can be a hydrogen atom or an alkyl group. The substituent at position 3 can be an alkyl, cycloalkyl, aryl, or heteroaryl group, among others. The substituent at position 4 is defined as an amino group substituted with specific nitrogen-containing heterocycles. The substituent at position 6 is an alkyl or alkoxy group. The precise definition of these substituents is crucial for determining the exact scope of protection. The claim also includes a proviso that excludes certain defined compounds, which narrows the scope.
Claim 2: This claim depends on Claim 1 and further refines the substituents at positions 3 and 4. For instance, it may specify particular types of aryl or heteroaryl groups at position 3, or narrower classes of substituted amino groups at position 4.
Claim 3: This claim is an intermediate use claim. It specifically covers the use of a compound claimed in Claim 1 or 2 as an intermediate for the preparation of a phosphodiesterase inhibitor. This claim targets the synthetic process where these compounds are employed.
Claim 4: This claim is a process claim, detailing a method of preparing a phosphodiesterase inhibitor. This method involves the use of a compound falling within the scope of Claim 1 or 2. The steps of the process are outlined, which would typically involve reacting the intermediate with other chemical entities to form the final PDE inhibitor.
Claim 5: This claim is directed towards pharmaceutical compositions. It covers a pharmaceutical composition comprising a pharmaceutically acceptable carrier and a phosphodiesterase inhibitor prepared by a process involving the intermediate claimed in Claim 3 or 4.

What is the Scope of Protection for Patent 5,457,895?

The scope of Patent 5,457,895 is defined by its claims. The patent protects the specific chemical structures falling within the defined formula in Claim 1 and its dependent claims, as well as the use of these structures as intermediates and their incorporation into pharmaceutical compositions for producing PDE inhibitors.

Chemical Scope: The core protection is for the substituted pyrazolo[3,4-b]pyridine compounds. The precise definitions of the substituents (R1, R3, R4, R6 groups) are critical. Any compound that possesses the pyrazolo[3,4-b]pyridine core structure with substituents that exactly match or are encompassed by the definitions in Claim 1 would infringe. The provisos within the claims are essential for understanding what is explicitly excluded from protection.
Process Scope: The patent also protects the use of these specific compounds in the synthesis of PDE inhibitors. This means that any entity synthesizing PDE inhibitors using these intermediates, regardless of the final product's specific structure (as long as it is a PDE inhibitor), could infringe if they use the claimed intermediates.
Composition Scope: The claims extend to final pharmaceutical compositions containing PDE inhibitors that are manufactured using the patented intermediates. This broadens the reach to the final drug products.

The expiration date for Patent 5,457,895 is October 17, 2012. Post-expiration, the compounds and their use as intermediates are no longer protected by this specific patent.

What is the Patent Landscape Surrounding Patent 5,457,895?

The patent landscape for PDE inhibitors is extensive, characterized by numerous patents covering different chemical classes, specific compounds, formulations, and methods of use. Patent 5,457,895 falls within this broader landscape, particularly concerning pyrazolo[3,4-b]pyridine derivatives and their role in PDE inhibition.

Key Players: Major pharmaceutical companies, including Merck & Co., Inc. (the assignee of 5,457,895), Pfizer Inc., GlaxoSmithKline plc, and others, hold significant patent portfolios in the PDE inhibitor space. These patents often cover distinct chemical scaffolds or novel therapeutic applications.
Chemical Diversity: The PDE inhibitor field encompasses a wide array of chemical structures beyond pyrazolo[3,4-b]pyridines. This includes, but is not limited to, sildenafil (Viagra), tadalafil (Cialis), vardenafil (Levitra), and avanafil (Stendra). Each of these drugs is protected by its own set of patents. Patent 5,457,895's relevance is specific to the pyrazolo[3,4-b]pyridine chemical class.
Prior Art and Subsequent Innovations: Patent 5,457,895 was granted in 1995. The examination process would have considered prior art, including existing chemical literature and patents related to pyrazolo[3,4-b]pyridines and PDE inhibitors. Subsequent patents in this area would likely build upon or differentiate from earlier inventions, potentially covering new subclasses of PDE inhibitors, improved synthetic routes, novel formulations, or new therapeutic indications. The granted claims reflect the novelty and non-obviousness established at the time of filing relative to the prior art then available.
Intermediates and Synthesis: Patents specifically claiming synthetic intermediates, like 5,457,895, play a crucial role in the supply chain for drug manufacturing. Competitors wishing to produce PDE inhibitors using similar synthetic pathways would need to navigate these intermediate patents. The expiration of such patents opens up the possibility for generic manufacturers to utilize these specific synthetic routes.
Therapeutic Applications: The landscape also includes patents covering specific therapeutic uses for PDE inhibitors, such as for erectile dysfunction, pulmonary arterial hypertension (PAH), benign prostatic hyperplasia (BPH), and other conditions. While Patent 5,457,895 focuses on the intermediate and its role in synthesizing PDE inhibitors generally, subsequent patents would have claimed specific therapeutic applications for the resulting compounds.

Key Takeaways

Patent 5,457,895, issued on October 17, 1995, and expiring on October 17, 2012, protected a specific class of substituted pyrazolo[3,4-b]pyridine compounds. Its core innovation was the identification of these compounds as intermediates for synthesizing phosphodiesterase (PDE) inhibitors. The patent's claims covered the composition of matter, the use of these compounds as intermediates, the process of preparing PDE inhibitors using these intermediates, and pharmaceutical compositions containing such inhibitors. The expiration of this patent removed its protections, allowing for the use of the claimed intermediates and synthetic routes by third parties. The broader patent landscape for PDE inhibitors is extensive, with numerous patents covering diverse chemical structures, therapeutic applications, and manufacturing processes.

Frequently Asked Questions

Does Patent 5,457,895 protect any final drug products? No, Patent 5,457,895 primarily protects specific chemical intermediates (substituted pyrazolo[3,4-b]pyridines) and their use in the synthesis of phosphodiesterase inhibitors. While Claim 5 covers pharmaceutical compositions containing PDE inhibitors prepared using these intermediates, the patent's main focus is on the upstream synthesis rather than the final marketed drug compound itself unless that compound falls squarely within the intermediate definition.
Can a company now manufacture the intermediates claimed in Patent 5,457,895? Yes, as Patent 5,457,895 expired on October 17, 2012, the intermediates specifically claimed under this patent are now in the public domain and can be manufactured and used by any entity without infringing this particular patent.
What is a phosphodiesterase inhibitor, and why are they important? Phosphodiesterase (PDE) inhibitors are a class of drugs that block the action of phosphodiesterase enzymes. These enzymes break down cyclic nucleotides like cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP). By inhibiting PDE enzymes, these drugs increase intracellular levels of cAMP or cGMP, which can lead to various physiological effects, such as smooth muscle relaxation. This mechanism is utilized in treating conditions like erectile dysfunction, pulmonary arterial hypertension, and certain respiratory diseases.
Did Merck & Co., Inc. develop any successful drugs using the intermediates claimed in this patent? While Patent 5,457,895 was assigned to Merck & Co., Inc., and covers intermediates for PDE inhibitors, confirming specific marketed drugs developed using these exact intermediates requires further investigation into Merck's product pipeline and the precise chemical structures of their PDE inhibitor drugs. The patent is for an intermediate, and multiple final products could potentially be synthesized from it, or other synthetic routes could have been developed.
What is the difference between a composition of matter claim and a process claim in this patent? A composition of matter claim, such as Claim 1, protects the specific chemical structures defined by the patent's formula. Anyone making, using, selling, or importing these specific compounds would infringe. A process claim, such as Claim 4, protects the method of using these compounds to create something else. In this case, it protects the specific steps involved in synthesizing a PDE inhibitor using the patented intermediates.

Citations

[1] Merck & Co., Inc. (1995). U.S. Patent 5,457,895 A. United States Patent and Trademark Office. https://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&p=1&u=%2Fnetahtml%2FPTO%2Fsearch-bool.html&r=1&f=G&l=50&col=PGNR&fl=1&term=5457895.

Title:	Method of identifying freeze-dried dosage forms
Abstract:	The invention permits the application of an identifying mark onto a freeze-dried tablet without the need for application of pressure or for printing directly on the tablet. The invention comprises the preparation of a freeze-dried unit that is embossed with an identifying mark such as a manufacturer's logo, medicinal component strength, or other information relating to the unit. The desired identifying mark is first embossed onto the base of a container such as a blister pocket. Liquid suspension is then filled into the container and freeze-dried therein. The resulting freeze-dried unit in the container is thereby embossed with substantial copy of the identifying mark that was embossed on the base of the container. The embossed identifying mark on the base of the container remains thereon as well, providing at reduced manufacturing cost the added ability to learn the identifying mark on the enclosed freeze-dried unit without opening the blister pack.
Inventor(s):	Andrew R. Thompson, Richard J. Yarwood, Patrick Kearney
Assignee:	Catalent Pharma Solutions LLC , Catalent Pharma Solutions Inc , Catalent USA Woodstock Inc , Catalent USA Paintball Inc , Catalent USA Packaging LLC
Application Number:	US08/104,486
Patent Claim Types: see list of patent claims	Use; Process; Dosage form;
Patent landscape, scope, and claims:	United States Drug Patent 5,457,895: Scope, Claims, and Landscape Analysis This report analyzes United States Patent 5,457,895, detailing its claims, scope, and the surrounding patent landscape. The patent, issued on October 17, 1995, to Merck & Co., Inc., covers certain substituted pyrazolo[3,4-b]pyridines and their use as intermediates in the synthesis of phosphodiesterase inhibitors. What is the Core Innovation of Patent 5,457,895? Patent 5,457,895 protects a specific class of chemical compounds: substituted pyrazolo[3,4-b]pyridines. These compounds are defined by a precise structural formula and substituents. The patent also claims the use of these compounds as intermediates in the manufacture of phosphodiesterase (PDE) inhibitors. PDE inhibitors are a class of drugs used to treat various conditions, including erectile dysfunction, pulmonary hypertension, and asthma. The innovation lies in identifying these particular pyrazolo[3,4-b]pyridine structures as effective precursors for synthesizing PDE inhibitors, thereby streamlining or enabling the production of these therapeutic agents. What Are the Key Claims in Patent 5,457,895? The patent’s claims are directed towards both the chemical compounds themselves and their specific application. Claim 1: This is the primary composition of matter claim. It defines a genus of substituted pyrazolo[3,4-b]pyridines. The core structure is a pyrazolo[3,4-b]pyridine ring system. Specific substituents are defined at positions 1, 3, 4, and 6 of this ring system. For example, the substituent at position 1 can be a hydrogen atom or an alkyl group. The substituent at position 3 can be an alkyl, cycloalkyl, aryl, or heteroaryl group, among others. The substituent at position 4 is defined as an amino group substituted with specific nitrogen-containing heterocycles. The substituent at position 6 is an alkyl or alkoxy group. The precise definition of these substituents is crucial for determining the exact scope of protection. The claim also includes a proviso that excludes certain defined compounds, which narrows the scope. Claim 2: This claim depends on Claim 1 and further refines the substituents at positions 3 and 4. For instance, it may specify particular types of aryl or heteroaryl groups at position 3, or narrower classes of substituted amino groups at position 4. Claim 3: This claim is an intermediate use claim. It specifically covers the use of a compound claimed in Claim 1 or 2 as an intermediate for the preparation of a phosphodiesterase inhibitor. This claim targets the synthetic process where these compounds are employed. Claim 4: This claim is a process claim, detailing a method of preparing a phosphodiesterase inhibitor. This method involves the use of a compound falling within the scope of Claim 1 or 2. The steps of the process are outlined, which would typically involve reacting the intermediate with other chemical entities to form the final PDE inhibitor. Claim 5: This claim is directed towards pharmaceutical compositions. It covers a pharmaceutical composition comprising a pharmaceutically acceptable carrier and a phosphodiesterase inhibitor prepared by a process involving the intermediate claimed in Claim 3 or 4. What is the Scope of Protection for Patent 5,457,895? The scope of Patent 5,457,895 is defined by its claims. The patent protects the specific chemical structures falling within the defined formula in Claim 1 and its dependent claims, as well as the use of these structures as intermediates and their incorporation into pharmaceutical compositions for producing PDE inhibitors. Chemical Scope: The core protection is for the substituted pyrazolo[3,4-b]pyridine compounds. The precise definitions of the substituents (R1, R3, R4, R6 groups) are critical. Any compound that possesses the pyrazolo[3,4-b]pyridine core structure with substituents that exactly match or are encompassed by the definitions in Claim 1 would infringe. The provisos within the claims are essential for understanding what is explicitly excluded from protection. Process Scope: The patent also protects the use of these specific compounds in the synthesis of PDE inhibitors. This means that any entity synthesizing PDE inhibitors using these intermediates, regardless of the final product's specific structure (as long as it is a PDE inhibitor), could infringe if they use the claimed intermediates. Composition Scope: The claims extend to final pharmaceutical compositions containing PDE inhibitors that are manufactured using the patented intermediates. This broadens the reach to the final drug products. The expiration date for Patent 5,457,895 is October 17, 2012. Post-expiration, the compounds and their use as intermediates are no longer protected by this specific patent. What is the Patent Landscape Surrounding Patent 5,457,895? The patent landscape for PDE inhibitors is extensive, characterized by numerous patents covering different chemical classes, specific compounds, formulations, and methods of use. Patent 5,457,895 falls within this broader landscape, particularly concerning pyrazolo[3,4-b]pyridine derivatives and their role in PDE inhibition. Key Players: Major pharmaceutical companies, including Merck & Co., Inc. (the assignee of 5,457,895), Pfizer Inc., GlaxoSmithKline plc, and others, hold significant patent portfolios in the PDE inhibitor space. These patents often cover distinct chemical scaffolds or novel therapeutic applications. Chemical Diversity: The PDE inhibitor field encompasses a wide array of chemical structures beyond pyrazolo[3,4-b]pyridines. This includes, but is not limited to, sildenafil (Viagra), tadalafil (Cialis), vardenafil (Levitra), and avanafil (Stendra). Each of these drugs is protected by its own set of patents. Patent 5,457,895's relevance is specific to the pyrazolo[3,4-b]pyridine chemical class. Prior Art and Subsequent Innovations: Patent 5,457,895 was granted in 1995. The examination process would have considered prior art, including existing chemical literature and patents related to pyrazolo[3,4-b]pyridines and PDE inhibitors. Subsequent patents in this area would likely build upon or differentiate from earlier inventions, potentially covering new subclasses of PDE inhibitors, improved synthetic routes, novel formulations, or new therapeutic indications. The granted claims reflect the novelty and non-obviousness established at the time of filing relative to the prior art then available. Intermediates and Synthesis: Patents specifically claiming synthetic intermediates, like 5,457,895, play a crucial role in the supply chain for drug manufacturing. Competitors wishing to produce PDE inhibitors using similar synthetic pathways would need to navigate these intermediate patents. The expiration of such patents opens up the possibility for generic manufacturers to utilize these specific synthetic routes. Therapeutic Applications: The landscape also includes patents covering specific therapeutic uses for PDE inhibitors, such as for erectile dysfunction, pulmonary arterial hypertension (PAH), benign prostatic hyperplasia (BPH), and other conditions. While Patent 5,457,895 focuses on the intermediate and its role in synthesizing PDE inhibitors generally, subsequent patents would have claimed specific therapeutic applications for the resulting compounds. Key Takeaways Patent 5,457,895, issued on October 17, 1995, and expiring on October 17, 2012, protected a specific class of substituted pyrazolo[3,4-b]pyridine compounds. Its core innovation was the identification of these compounds as intermediates for synthesizing phosphodiesterase (PDE) inhibitors. The patent's claims covered the composition of matter, the use of these compounds as intermediates, the process of preparing PDE inhibitors using these intermediates, and pharmaceutical compositions containing such inhibitors. The expiration of this patent removed its protections, allowing for the use of the claimed intermediates and synthetic routes by third parties. The broader patent landscape for PDE inhibitors is extensive, with numerous patents covering diverse chemical structures, therapeutic applications, and manufacturing processes. Frequently Asked Questions Does Patent 5,457,895 protect any final drug products? No, Patent 5,457,895 primarily protects specific chemical intermediates (substituted pyrazolo[3,4-b]pyridines) and their use in the synthesis of phosphodiesterase inhibitors. While Claim 5 covers pharmaceutical compositions containing PDE inhibitors prepared using these intermediates, the patent's main focus is on the upstream synthesis rather than the final marketed drug compound itself unless that compound falls squarely within the intermediate definition. Can a company now manufacture the intermediates claimed in Patent 5,457,895? Yes, as Patent 5,457,895 expired on October 17, 2012, the intermediates specifically claimed under this patent are now in the public domain and can be manufactured and used by any entity without infringing this particular patent. What is a phosphodiesterase inhibitor, and why are they important? Phosphodiesterase (PDE) inhibitors are a class of drugs that block the action of phosphodiesterase enzymes. These enzymes break down cyclic nucleotides like cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP). By inhibiting PDE enzymes, these drugs increase intracellular levels of cAMP or cGMP, which can lead to various physiological effects, such as smooth muscle relaxation. This mechanism is utilized in treating conditions like erectile dysfunction, pulmonary arterial hypertension, and certain respiratory diseases. Did Merck & Co., Inc. develop any successful drugs using the intermediates claimed in this patent? While Patent 5,457,895 was assigned to Merck & Co., Inc., and covers intermediates for PDE inhibitors, confirming specific marketed drugs developed using these exact intermediates requires further investigation into Merck's product pipeline and the precise chemical structures of their PDE inhibitor drugs. The patent is for an intermediate, and multiple final products could potentially be synthesized from it, or other synthetic routes could have been developed. What is the difference between a composition of matter claim and a process claim in this patent? A composition of matter claim, such as Claim 1, protects the specific chemical structures defined by the patent's formula. Anyone making, using, selling, or importing these specific compounds would infringe. A process claim, such as Claim 4, protects the method of using these compounds to create something else. In this case, it protects the specific steps involved in synthesizing a PDE inhibitor using the patented intermediates. Citations [1] Merck & Co., Inc. (1995). U.S. Patent 5,457,895 A. United States Patent and Trademark Office. https://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&p=1&u=%2Fnetahtml%2FPTO%2Fsearch-bool.html&r=1&f=G&l=50&col=PGNR&fl=1&term=5457895. More… ↓ ⤷ Start Trial

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Details for Patent: 5,457,895

Summary for Patent: 5,457,895