US Patent 5,149,694: Scope, Claims, and Landscape Analysis

US Patent 5,149,694, titled "Substituted benzimidazoles and their use as H+-K+-ATPase inhibitors," was granted on September 22, 1992, to Merck & Co., Inc. This patent covers a class of chemical compounds and their therapeutic application. The primary focus of the patent is on substituted benzimidazoles, specifically those exhibiting inhibitory activity against the hydrogen-potassium ATPase (H+-K+-ATPase) enzyme. This enzyme is crucial in the parietal cells of the stomach for the secretion of gastric acid. Compounds falling under this patent’s claims are intended for the treatment of acid-related gastrointestinal disorders.

What Are the Core Inventions Claimed in US Patent 5,149,694?

The patent’s claims delineate a specific chemical space and its application. The core inventions revolve around the chemical structure of the active compounds and their pharmacological use.

What is the Claimed Chemical Structure?

Claim 1 of US Patent 5,149,694 defines the chemical structure of the compounds. It specifies a genus of substituted benzimidazoles with particular substituents at defined positions of the benzimidazole ring.

Core Structure: A benzimidazole ring system.
Substituents: The claims detail specific groups attached to the benzimidazole core. These typically include:
- A substituent at the 2-position of the benzimidazole ring, often a pyridine ring substituted with specific groups like methoxy or difluoromethoxy at the 3- or 4-position.
- A substituent at the 5- (or 6-) position of the benzimidazole ring, frequently an alkyl group such as methyl.
Stereochemistry: The claims also encompass stereoisomers, including racemates and enantiomers, of the defined compounds.

The patent provides a generic formula (Formula I) that encapsulates this defined chemical space. For example, a key embodiment of the invention, and a compound that later became clinically significant, is Omeprazole. While Omeprazole is not explicitly named as an individual compound within the broadest claims, it falls squarely within the defined structural genus.

What is the Claimed Therapeutic Use?

The patent explicitly claims the use of these substituted benzimidazoles as inhibitors of H+-K+-ATPase. This mechanism of action is directly linked to their therapeutic application.

Mechanism of Action: Inhibition of the gastric H+-K+-ATPase enzyme.
Therapeutic Application: Treatment of hyperacidic conditions in the gastrointestinal tract. This includes conditions such as:
- Peptic ulcer disease (gastric and duodenal ulcers)
- Gastroesophageal reflux disease (GERD)
- Zollinger-Ellison syndrome
- Erosive esophagitis

The patent asserts that these compounds provide an effective and well-tolerated method for reducing gastric acid secretion.

How is the Patent's Scope Defined?

The scope of US Patent 5,149,694 is determined by its independent claims, particularly Claim 1, and the dependent claims that further refine these. The broadest claims define a wide array of compounds with potential for H+-K+-ATPase inhibition.

Claim 1: This claim is a Markush claim, defining a generic chemical structure. It encompasses numerous specific chemical entities by outlining permissible variations in substituents.
Dependent Claims: These claims narrow the scope by adding further limitations or specifying particular embodiments of the generic formula. They might define specific substituents, stereochemical configurations, or pharmaceutical compositions.
Formulations: The patent also includes claims directed to pharmaceutical compositions containing the claimed benzimidazole compounds, along with pharmaceutically acceptable carriers.

The interpretation of the scope relies heavily on understanding the definitions of the various radicals and substituents specified within the claims, as well as their interrelationships.

What is the Patent Landscape for US Patent 5,149,694?

The patent landscape surrounding US Patent 5,149,694 is characterized by its association with a highly successful class of drugs and subsequent patent challenges and extensions.

Key Developments and Associated Drugs

US Patent 5,149,694 is foundational to the development of proton pump inhibitors (PPIs). Omeprazole (Prilosec®) is the most prominent drug developed under the umbrella of this patent's foundational technology.

Omeprazole: The first commercially successful PPI. Its development and commercialization by AstraZeneca (originally by Astra AB) were directly linked to the intellectual property covered by this patent and its foreign equivalents.
Esomeprazole (Nexium®): A later development by AstraZeneca, esomeprazole is the S-enantiomer of omeprazole. While it is a distinct chemical entity, its development is intrinsically tied to the foundational chemistry and patent protection of omeprazole and its class.

Litigation and Patent Expirations

The patent's lifespan and its litigation history are critical for understanding the competitive landscape.

Original Expiration: US Patent 5,149,694 was granted in 1992. Patents granted under the old patent law (pre-1995) had a term of 17 years from the grant date or 20 years from the filing date, whichever was longer. For this patent, the filing date was October 24, 1990, leading to a potential expiration around October 2010 (20 years from filing).
Patent Term Extension (PTE): Due to regulatory delays in obtaining FDA approval for Omeprazole, Merck & Co., Inc. was eligible for and received a Patent Term Extension for US Patent 5,149,694. This extension added significant time to the patent's effective life. The PTE typically aims to compensate for lost patent term during the regulatory review process.
- The effective expiration date for this patent, including the PTE, extended into the mid-2000s. Specifically, it was extended until September 15, 2004 [1, 2]. This extension was crucial for recouping development costs for Omeprazole.
Subsequent Patents: Following the expiration of this foundational patent, the patent landscape for Omeprazole and related PPIs became more crowded. New patents emerged covering:
- Enantiomers (e.g., patents covering esomeprazole).
- New formulations (e.g., delayed-release, oral suspensions).
- Specific manufacturing processes.
- Combination therapies.
Generics: The expiration of US Patent 5,149,694 and subsequent related patents allowed for the market entry of generic versions of omeprazole, significantly impacting market dynamics and pricing.

Related Patents and Technologies

The intellectual property surrounding benzimidazole H+-K+-ATPase inhibitors is extensive. Beyond the foundational patent, numerous other patents exist.

Structure-Activity Relationship Patents: Patents covering specific modifications or analogues of the core benzimidazole structure.
Process Patents: Patents claiming novel or improved methods for synthesizing the active pharmaceutical ingredients.
Formulation Patents: Patents for specific drug delivery systems or compositions designed to enhance stability, bioavailability, or patient compliance.

The landscape is a complex web of overlapping and sequential patent filings designed to protect various aspects of the drug's lifecycle, from initial discovery to advanced formulations.

What are the Implications for R&D and Investment?

The analysis of US Patent 5,149,694 has direct implications for research and development strategies and investment decisions within the pharmaceutical sector.

For R&D Strategy

Navigating Prior Art: Understanding the scope of US Patent 5,149,694 and its progeny is essential for identifying patentable areas. The broad claims of this patent highlight the significant prior art it represents for novel benzimidazole H+-K+-ATPase inhibitors.
Developing Novel Mechanisms: Research may need to focus on entirely new mechanisms of action for acid suppression or explore different chemical classes of compounds to avoid infringement.
Targeting Unmet Needs: Identifying specific patient populations or therapeutic niches within acid-related disorders not adequately addressed by existing PPIs could be a strategic R&D direction.
Next-Generation Formulations: While the core composition patent has expired, opportunities may exist for patenting innovative formulations or delivery systems of existing molecules, provided they offer a new and non-obvious advantage.

For Investment Decisions

Market Entry of Generics: The expiration of this patent opened the door for generic competition, which typically leads to price erosion and shifts in market share for branded products. Investors need to consider the impact of generic entry on revenue forecasts.
Pipeline Analysis: For companies developing acid-suppressing drugs, an understanding of this patent's historical significance and the broader patent landscape is crucial for assessing competitive threats and opportunities.
Licensing and Acquisition: Investors should evaluate companies based on their intellectual property portfolio's strength relative to foundational patents like US 5,149,694. Companies holding patents on improved formulations, novel delivery systems, or next-generation acid suppressors may present attractive acquisition or licensing targets.
Litigation Risk: The history of PPI litigation underscores the importance of thorough freedom-to-operate analyses. Investors should assess the litigation risk associated with any new entrant or product in this therapeutic area.

The expiration of US Patent 5,149,694 marked a significant transition point for the PPI market, moving from a period of strong branded protection to one dominated by generic competition and innovation in related areas like enantiomers and formulations.

Key Takeaways

US Patent 5,149,694 protects a broad class of substituted benzimidazoles as H+-K+-ATPase inhibitors, foundational to the development of proton pump inhibitors like Omeprazole. The patent's scope, defined by its Markush claims, covers a wide chemical space. Due to Patent Term Extension, its effective life extended to September 15, 2004, significantly impacting the market entry of generic Omeprazole. The expiration of this patent has led to a mature generics market and a landscape focused on subsequent innovations in formulations, enantiomers, and alternative acid suppression mechanisms.

Frequently Asked Questions

What specific chemical compounds are covered by US Patent 5,149,694?

The patent covers a generic class of substituted benzimidazoles defined by Formula I and its associated definitions of substituents. While specific compounds like Omeprazole fall within this genus, the patent's broadest claims do not list every individual molecule exhaustively.

When did US Patent 5,149,694 expire?

US Patent 5,149,694, with its Patent Term Extension, expired on September 15, 2004.

What is the therapeutic significance of H+-K+-ATPase inhibitors?

H+-K+-ATPase inhibitors are crucial for reducing gastric acid secretion. This mechanism makes them effective treatments for conditions such as peptic ulcers, GERD, and Zollinger-Ellison syndrome.

How did this patent influence the market for acid-reducing drugs?

This patent was instrumental in the development and commercialization of the first proton pump inhibitors (PPIs), a blockbuster class of drugs. Its eventual expiration paved the way for significant generic competition.

Are there any active patents still claiming Omeprazole or its direct analogues?

While US Patent 5,149,694 itself has expired, numerous other patents exist covering specific enantiomers (like esomeprazole), novel formulations, manufacturing processes, and new therapeutic uses of Omeprazole and related compounds.

Sources

United States Patent and Trademark Office. (1992). Patent Term Restoration; Notice of OMB Approval. Federal Register, 57(186), 43909-43910.
Food and Drug Administration. (1999). Proton pump inhibitors; Patent term restoration; Notice. Federal Register, 64(94), 24531-24532.

Title:	Combination of tobramycin and dexamethasone for topical ophthalmic use
Abstract:	Disclosed are pharmaceutical compositions comprising tobramycin and dexamethasone for topical ophthalmic delivery and a method of treatment comprising administering said composition when indicated for infection and control of inflammatory response for optimal wound healing and normalization of the eye.
Inventor(s):	Gerald D. Cagle, Thomas O. McDonald, Allan L. Rosenthal
Assignee:	Alcon Research LLC
Application Number:	US07/440,546
Patent Claim Types: see list of patent claims	Use; Composition;
Patent landscape, scope, and claims:	US Patent 5,149,694: Scope, Claims, and Landscape Analysis US Patent 5,149,694, titled "Substituted benzimidazoles and their use as H+-K+-ATPase inhibitors," was granted on September 22, 1992, to Merck & Co., Inc. This patent covers a class of chemical compounds and their therapeutic application. The primary focus of the patent is on substituted benzimidazoles, specifically those exhibiting inhibitory activity against the hydrogen-potassium ATPase (H+-K+-ATPase) enzyme. This enzyme is crucial in the parietal cells of the stomach for the secretion of gastric acid. Compounds falling under this patent’s claims are intended for the treatment of acid-related gastrointestinal disorders. What Are the Core Inventions Claimed in US Patent 5,149,694? The patent’s claims delineate a specific chemical space and its application. The core inventions revolve around the chemical structure of the active compounds and their pharmacological use. What is the Claimed Chemical Structure? Claim 1 of US Patent 5,149,694 defines the chemical structure of the compounds. It specifies a genus of substituted benzimidazoles with particular substituents at defined positions of the benzimidazole ring. Core Structure: A benzimidazole ring system. Substituents: The claims detail specific groups attached to the benzimidazole core. These typically include: A substituent at the 2-position of the benzimidazole ring, often a pyridine ring substituted with specific groups like methoxy or difluoromethoxy at the 3- or 4-position. A substituent at the 5- (or 6-) position of the benzimidazole ring, frequently an alkyl group such as methyl. Stereochemistry: The claims also encompass stereoisomers, including racemates and enantiomers, of the defined compounds. The patent provides a generic formula (Formula I) that encapsulates this defined chemical space. For example, a key embodiment of the invention, and a compound that later became clinically significant, is Omeprazole. While Omeprazole is not explicitly named as an individual compound within the broadest claims, it falls squarely within the defined structural genus. What is the Claimed Therapeutic Use? The patent explicitly claims the use of these substituted benzimidazoles as inhibitors of H+-K+-ATPase. This mechanism of action is directly linked to their therapeutic application. Mechanism of Action: Inhibition of the gastric H+-K+-ATPase enzyme. Therapeutic Application: Treatment of hyperacidic conditions in the gastrointestinal tract. This includes conditions such as: Peptic ulcer disease (gastric and duodenal ulcers) Gastroesophageal reflux disease (GERD) Zollinger-Ellison syndrome Erosive esophagitis The patent asserts that these compounds provide an effective and well-tolerated method for reducing gastric acid secretion. How is the Patent's Scope Defined? The scope of US Patent 5,149,694 is determined by its independent claims, particularly Claim 1, and the dependent claims that further refine these. The broadest claims define a wide array of compounds with potential for H+-K+-ATPase inhibition. Claim 1: This claim is a Markush claim, defining a generic chemical structure. It encompasses numerous specific chemical entities by outlining permissible variations in substituents. Dependent Claims: These claims narrow the scope by adding further limitations or specifying particular embodiments of the generic formula. They might define specific substituents, stereochemical configurations, or pharmaceutical compositions. Formulations: The patent also includes claims directed to pharmaceutical compositions containing the claimed benzimidazole compounds, along with pharmaceutically acceptable carriers. The interpretation of the scope relies heavily on understanding the definitions of the various radicals and substituents specified within the claims, as well as their interrelationships. What is the Patent Landscape for US Patent 5,149,694? The patent landscape surrounding US Patent 5,149,694 is characterized by its association with a highly successful class of drugs and subsequent patent challenges and extensions. Key Developments and Associated Drugs US Patent 5,149,694 is foundational to the development of proton pump inhibitors (PPIs). Omeprazole (Prilosec®) is the most prominent drug developed under the umbrella of this patent's foundational technology. Omeprazole: The first commercially successful PPI. Its development and commercialization by AstraZeneca (originally by Astra AB) were directly linked to the intellectual property covered by this patent and its foreign equivalents. Esomeprazole (Nexium®): A later development by AstraZeneca, esomeprazole is the S-enantiomer of omeprazole. While it is a distinct chemical entity, its development is intrinsically tied to the foundational chemistry and patent protection of omeprazole and its class. Litigation and Patent Expirations The patent's lifespan and its litigation history are critical for understanding the competitive landscape. Original Expiration: US Patent 5,149,694 was granted in 1992. Patents granted under the old patent law (pre-1995) had a term of 17 years from the grant date or 20 years from the filing date, whichever was longer. For this patent, the filing date was October 24, 1990, leading to a potential expiration around October 2010 (20 years from filing). Patent Term Extension (PTE): Due to regulatory delays in obtaining FDA approval for Omeprazole, Merck & Co., Inc. was eligible for and received a Patent Term Extension for US Patent 5,149,694. This extension added significant time to the patent's effective life. The PTE typically aims to compensate for lost patent term during the regulatory review process. The effective expiration date for this patent, including the PTE, extended into the mid-2000s. Specifically, it was extended until September 15, 2004 [1, 2]. This extension was crucial for recouping development costs for Omeprazole. Subsequent Patents: Following the expiration of this foundational patent, the patent landscape for Omeprazole and related PPIs became more crowded. New patents emerged covering: Enantiomers (e.g., patents covering esomeprazole). New formulations (e.g., delayed-release, oral suspensions). Specific manufacturing processes. Combination therapies. Generics: The expiration of US Patent 5,149,694 and subsequent related patents allowed for the market entry of generic versions of omeprazole, significantly impacting market dynamics and pricing. Related Patents and Technologies The intellectual property surrounding benzimidazole H+-K+-ATPase inhibitors is extensive. Beyond the foundational patent, numerous other patents exist. Structure-Activity Relationship Patents: Patents covering specific modifications or analogues of the core benzimidazole structure. Process Patents: Patents claiming novel or improved methods for synthesizing the active pharmaceutical ingredients. Formulation Patents: Patents for specific drug delivery systems or compositions designed to enhance stability, bioavailability, or patient compliance. The landscape is a complex web of overlapping and sequential patent filings designed to protect various aspects of the drug's lifecycle, from initial discovery to advanced formulations. What are the Implications for R&D and Investment? The analysis of US Patent 5,149,694 has direct implications for research and development strategies and investment decisions within the pharmaceutical sector. For R&D Strategy Navigating Prior Art: Understanding the scope of US Patent 5,149,694 and its progeny is essential for identifying patentable areas. The broad claims of this patent highlight the significant prior art it represents for novel benzimidazole H+-K+-ATPase inhibitors. Developing Novel Mechanisms: Research may need to focus on entirely new mechanisms of action for acid suppression or explore different chemical classes of compounds to avoid infringement. Targeting Unmet Needs: Identifying specific patient populations or therapeutic niches within acid-related disorders not adequately addressed by existing PPIs could be a strategic R&D direction. Next-Generation Formulations: While the core composition patent has expired, opportunities may exist for patenting innovative formulations or delivery systems of existing molecules, provided they offer a new and non-obvious advantage. For Investment Decisions Market Entry of Generics: The expiration of this patent opened the door for generic competition, which typically leads to price erosion and shifts in market share for branded products. Investors need to consider the impact of generic entry on revenue forecasts. Pipeline Analysis: For companies developing acid-suppressing drugs, an understanding of this patent's historical significance and the broader patent landscape is crucial for assessing competitive threats and opportunities. Licensing and Acquisition: Investors should evaluate companies based on their intellectual property portfolio's strength relative to foundational patents like US 5,149,694. Companies holding patents on improved formulations, novel delivery systems, or next-generation acid suppressors may present attractive acquisition or licensing targets. Litigation Risk: The history of PPI litigation underscores the importance of thorough freedom-to-operate analyses. Investors should assess the litigation risk associated with any new entrant or product in this therapeutic area. The expiration of US Patent 5,149,694 marked a significant transition point for the PPI market, moving from a period of strong branded protection to one dominated by generic competition and innovation in related areas like enantiomers and formulations. Key Takeaways US Patent 5,149,694 protects a broad class of substituted benzimidazoles as H+-K+-ATPase inhibitors, foundational to the development of proton pump inhibitors like Omeprazole. The patent's scope, defined by its Markush claims, covers a wide chemical space. Due to Patent Term Extension, its effective life extended to September 15, 2004, significantly impacting the market entry of generic Omeprazole. The expiration of this patent has led to a mature generics market and a landscape focused on subsequent innovations in formulations, enantiomers, and alternative acid suppression mechanisms. Frequently Asked Questions What specific chemical compounds are covered by US Patent 5,149,694? The patent covers a generic class of substituted benzimidazoles defined by Formula I and its associated definitions of substituents. While specific compounds like Omeprazole fall within this genus, the patent's broadest claims do not list every individual molecule exhaustively. When did US Patent 5,149,694 expire? US Patent 5,149,694, with its Patent Term Extension, expired on September 15, 2004. What is the therapeutic significance of H+-K+-ATPase inhibitors? H+-K+-ATPase inhibitors are crucial for reducing gastric acid secretion. This mechanism makes them effective treatments for conditions such as peptic ulcers, GERD, and Zollinger-Ellison syndrome. How did this patent influence the market for acid-reducing drugs? This patent was instrumental in the development and commercialization of the first proton pump inhibitors (PPIs), a blockbuster class of drugs. Its eventual expiration paved the way for significant generic competition. Are there any active patents still claiming Omeprazole or its direct analogues? While US Patent 5,149,694 itself has expired, numerous other patents exist covering specific enantiomers (like esomeprazole), novel formulations, manufacturing processes, and new therapeutic uses of Omeprazole and related compounds. Sources United States Patent and Trademark Office. (1992). Patent Term Restoration; Notice of OMB Approval. Federal Register, 57(186), 43909-43910. Food and Drug Administration. (1999). Proton pump inhibitors; Patent term restoration; Notice. Federal Register, 64(94), 24531-24532. More… ↓ ⤷ Start Trial

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Details for Patent: 5,149,694

Summary for Patent: 5,149,694