United States Patent 5,246,937: A Detailed Analysis of Scope, Claims, and Patent Landscape
Introduction
United States Patent 5,246,937, titled "Purine derivatives," is a significant patent in the field of pharmaceuticals, particularly for the treatment of viral infections. This analysis will delve into the scope, claims, and the broader patent landscape surrounding this invention.
Patent Overview
Publication Details
- Publication Number: US5246937A
- Authority: United States
- Prior Art Date: December 6, 1991
- Legal Status: Expired - Lifetime[4].
Invention Description
The patent describes a series of purine derivatives, which are compounds potentially useful in the treatment of infections caused by herpes viruses, such as herpes simplex type 1. These compounds are part of a broader class of heterocyclic compounds containing purine ring systems[4].
Scope of the Invention
Chemical Structure and Composition
The patent focuses on compounds of Formula (I), which are characterized by specific substitutions on the purine ring. These compounds can be in crystalline form or as hydrates, and they may also be present as pharmaceutically acceptable salts. The invention includes methods for preparing these compounds, such as hydrolysis and catalytic reduction[4].
Pharmaceutical Applications
The compounds are intended for use as active therapeutic substances, particularly in the treatment of viral infections. The patent highlights the pharmaceutical activity of these compounds, which was not previously indicated in earlier publications[4].
Claims of the Patent
Independent and Dependent Claims
The patent includes several claims that define the scope of the invention. These claims cover:
- The chemical structure of the purine derivatives (Formula I).
- Methods of preparing these compounds.
- Pharmaceutical compositions containing these compounds.
- Methods of treatment using these compounds[4].
Claim Specificity
The claims are detailed to ensure that the invention is clearly defined and distinguishable from prior art. For example, Claim 1 might specify the exact chemical structure of the compound, while dependent claims might detail specific methods of preparation or pharmaceutical uses[4].
Patent Landscape
Prior Art and Related Patents
The patent is a divisional of earlier applications (Ser. No. 07/285,399 and Ser. No. 777,188), indicating a development process that built upon previous research. The invention also references earlier publications, such as Synthetic Communications, which described similar compounds but without indicating their pharmaceutical activity[4].
International Patent Family
To understand the global reach of this invention, one would need to search international patent databases, such as those provided by the European Patent Office (EPO), Japan Patent Office (JPO), and the World Intellectual Property Organization (WIPO)[1].
Search Tools and Resources
For a comprehensive analysis, tools like the USPTO's Patent Public Search, Global Dossier, and the Common Citation Document (CCD) can be used to identify related patents and prior art. These resources help in visualizing the patent family and understanding the citation data from various IP offices[1].
Economic and Market Impact
Pharmaceutical Market
The expiration of the patent has significant implications for the pharmaceutical market. Generic versions of the drug can now be produced, potentially reducing costs and increasing accessibility for patients. This is evident from disputes over generic versions of herpes drugs, as seen in the case involving Novartis[5].
Research and Development
The data from the Patent Claims Research Dataset by the USPTO can provide insights into the trends and scope of patents in the pharmaceutical sector. This dataset includes detailed information on claims from US patents and applications, which can help in understanding the broader research and development landscape[3].
Legal and Regulatory Aspects
Orange Book Listing
The patent was listed in the Orange Book in 1994, which is a catalog of approved drug products with therapeutic equivalence evaluations. The listing indicates that the patent was recognized as protecting a method of use, although disputes arose regarding the scope of this protection[5].
Office Actions and Examination
The Patent Examination Data System (PEDS) and the Global Dossier can provide information on office actions and the examination history of the patent. This is crucial for understanding any challenges or modifications made during the patent application process[1].
Key Takeaways
- Chemical Structure and Composition: The patent focuses on purine derivatives with specific substitutions, useful in treating herpes infections.
- Pharmaceutical Applications: The compounds are intended for therapeutic use, with detailed methods of preparation and pharmaceutical compositions.
- Claims and Scope: The patent includes detailed claims defining the chemical structure, preparation methods, and pharmaceutical uses.
- Patent Landscape: The invention is part of a broader patent family with international implications, and its expiration affects the pharmaceutical market.
- Economic and Market Impact: The patent's expiration allows for generic drug production, impacting market costs and accessibility.
FAQs
Q: What is the primary use of the compounds described in US5246937A?
A: The primary use of the compounds is in the treatment of viral infections, particularly those caused by herpes viruses.
Q: How can one search for related patents and prior art?
A: Tools like the USPTO's Patent Public Search, Global Dossier, and the Common Citation Document (CCD) can be used to identify related patents and prior art.
Q: What is the significance of the patent being listed in the Orange Book?
A: The listing in the Orange Book indicates that the patent was recognized as protecting a method of use, which is important for regulatory and therapeutic equivalence evaluations.
Q: How does the expiration of the patent affect the pharmaceutical market?
A: The expiration allows generic versions of the drug to be produced, potentially reducing costs and increasing accessibility for patients.
Q: Where can one find detailed information on the claims and scope of US patents?
A: The Patent Claims Research Dataset by the USPTO provides detailed information on claims from US patents and applications.
Sources
- USPTO - Search for patents: https://www.uspto.gov/patents/search
- U.S. Department of Commerce - U.S. Patent and Trademark Office: https://www.commerce.gov/bureaus-and-offices/uspto
- USPTO - Patent Claims Research Dataset: https://www.uspto.gov/ip-policy/economic-research/research-datasets/patent-claims-research-dataset
- Google Patents - US5246937A: https://patents.google.com/patent/US5246937
- The Fda Law Blog - Flare-Up Over Generic Herpes Drug Could be Short-Lived: https://www.thefdalawblog.com/2010/09/flare-up-over-generic-herpes-drug-could-be-short-lived/
