United States Patent 4,738,974: A Detailed Analysis of Scope, Claims, and Patent Landscape
Introduction
United States Patent 4,738,974, assigned to AstraZeneca, is a pivotal patent in the pharmaceutical industry, particularly for the drug esomeprazole magnesium, marketed as NEXIUM. This patent has been a subject of significant interest due to its impact on the treatment of gastrointestinal diseases and the complex patent landscape surrounding it.
Background of the Patent
The patent in question, U.S. Patent 4,738,974, was granted for the compound esomeprazole magnesium, a proton pump inhibitor used to treat conditions such as erosive esophagitis, gastroesophageal reflux disease (GERD), and other gastrointestinal disorders. The patent was a result of extensive research and development by AstraZeneca, which led to the approval of NEXIUM by the FDA in 2001[1].
Scope of the Patent
Claims
The patent claims cover the specific chemical compound esomeprazole magnesium, its method of preparation, and its use in treating various gastrointestinal conditions. The claims are detailed and specific, ensuring that the patent protection is robust against potential generic competitors.
Patent Scope Metrics
Research on patent scope often involves metrics such as independent claim length and independent claim count. These metrics can indicate the breadth and clarity of the patent claims. For U.S. Patent 4,738,974, the claims are well-defined and narrow, which is consistent with higher probabilities of grant and shorter examination processes[3].
Regulatory Review and Patent Extension
Regulatory Review Period
The FDA determined the regulatory review period for NEXIUM to be 1,284 days, which includes 838 days in the testing phase and 446 days in the approval phase. This period is crucial for determining the potential extension of the patent term under the Drug Price Competition and Patent Term Restoration Act of 1984[1].
Patent Term Extension
The regulatory review period forms the basis for a patent term extension. For U.S. Patent 4,738,974, the applicant sought an extension of 865 days. However, the actual extension granted would be subject to statutory limitations and the diligence of the applicant during the regulatory review period[1].
Patent Landscape and Litigation
Orange Book Listings
The patents related to esomeprazole magnesium, including U.S. Patent 4,738,974, are listed in the FDA's "Orange Book," which is a publication of approved drug products with therapeutic equivalence evaluations. This listing is critical for generic drug manufacturers who must certify their compliance with these patents when filing Abbreviated New Drug Applications (ANDAs)[2].
Generic Challenges and Paragraph IV Certifications
Generic drug manufacturers often challenge the patents listed in the Orange Book by filing ANDAs with Paragraph IV certifications. This process can lead to litigation, as seen in cases where AstraZeneca defended its patents against generic competitors. The Federal Circuit has established that a threat of litigation from a patent holder can create a justiciable controversy, allowing generic manufacturers to seek declaratory judgments on the validity and infringement of these patents[2].
Impact on the Pharmaceutical Industry
Market Exclusivity
The patent protection for NEXIUM has allowed AstraZeneca to maintain market exclusivity for a significant period. This exclusivity is crucial for recouping the substantial investment in research and development and for generating revenue before generic competition enters the market.
Innovation and Competition
The patent landscape surrounding NEXIUM highlights the delicate balance between innovation and competition in the pharmaceutical industry. While patents like U.S. Patent 4,738,974 incentivize innovation by protecting intellectual property, they also face challenges from generic manufacturers seeking to enter the market. This dynamic ensures that there is continuous innovation while also providing access to affordable medications once the patent term expires.
Global Patent System Integration
Global Dossier and Common Citation Document
The global patent system, facilitated by services like the Global Dossier and the Common Citation Document, allows for the integration of patent data across different jurisdictions. This integration helps in managing the complex patent landscape by providing a single point of access to citation data and file histories of related applications, which is particularly useful for patents like U.S. Patent 4,738,974 that have international implications[4].
Conclusion
U.S. Patent 4,738,974 is a cornerstone in the pharmaceutical industry, particularly for the treatment of gastrointestinal diseases. Its scope and claims are well-defined, and the patent has navigated a complex regulatory and litigation landscape. Understanding this patent's impact is crucial for both innovator companies and generic manufacturers as they navigate the intricate world of pharmaceutical patents.
Key Takeaways
- Patent Scope and Claims: U.S. Patent 4,738,974 covers the compound esomeprazole magnesium, its preparation, and its use in treating gastrointestinal conditions.
- Regulatory Review and Patent Extension: The FDA determined a regulatory review period of 1,284 days, which is crucial for patent term extension.
- Patent Landscape and Litigation: The patent is listed in the Orange Book and has faced challenges from generic manufacturers through Paragraph IV certifications.
- Impact on the Pharmaceutical Industry: The patent has maintained market exclusivity for AstraZeneca while balancing innovation and competition.
- Global Patent System Integration: Services like the Global Dossier and Common Citation Document facilitate the management of international patent data.
FAQs
Q: What is the primary compound covered by U.S. Patent 4,738,974?
A: The primary compound covered is esomeprazole magnesium, marketed as NEXIUM.
Q: How was the regulatory review period for NEXIUM determined?
A: The FDA determined the regulatory review period to be 1,284 days, including 838 days in the testing phase and 446 days in the approval phase.
Q: What is the significance of the Orange Book listing for U.S. Patent 4,738,974?
A: The listing in the Orange Book is crucial for generic drug manufacturers who must certify their compliance with these patents when filing ANDAs.
Q: How do generic manufacturers challenge patents like U.S. Patent 4,738,974?
A: Generic manufacturers challenge these patents by filing ANDAs with Paragraph IV certifications, which can lead to litigation.
Q: What is the role of the Global Dossier in managing international patent data?
A: The Global Dossier provides a single point of access to file histories and citation data of related applications across different jurisdictions.
Sources
- Food and Drug Administration. Determination of Regulatory Review Period for Purposes of Patent Extension for NEXIUM.
- United States District Court. NOT FOR PUBLICATION UNITED STATES DISTRICT COURT.
- SSRN. Patent Claims and Patent Scope.
- USPTO. Search for patents - USPTO.
