Understanding the Scope and Claims of United States Patent 5,565,473
Introduction
United States Patent 5,565,473, titled "Unsaturated hydroxyalkylquinoline acids as leukotriene antagonists," is a significant patent in the pharmaceutical industry, particularly for the drug Singulair® (montelukast sodium). This patent, assigned to Merck Frosst Canada, Inc., has been the subject of extensive legal and scientific scrutiny.
Patent Overview
Title and Abstract
The patent covers compounds with specific chemical structures that act as leukotriene antagonists. These compounds are used in the treatment and prevention of various human disease states, including allergic reactions and inflammatory conditions[4].
Inventors and Assignee
The inventors listed on the patent include Michel L. Belley, Pierrefonds; Serge Leger, Dollard des Ormeaux; Marc Labelle, Ville d'Ile Perrot; Patrick Roy; Yi B. Xiang, both of Pierrefonds; and Daniel Guay, Montreal, all from Canada. The assignee is Merck Frosst Canada, Inc., based in Kirkland, Canada[4].
Filing and Approval Dates
The patent application was filed on February 23, 1995, and the patent was granted on October 15, 1996. It is a continuation of several earlier applications, dating back to 1990[4].
Claims and Coverage
Compound and Composition Claims
The patent claims cover specific chemical compounds, their compositions, and their use as leukotriene antagonists. These compounds are characterized by their unsaturated hydroxyalkylquinoline acid structures[4].
Pharmaceutical Compositions
The patent also describes various pharmaceutical compositions suitable for oral administration, including capsules, tablets, powders, granules, solutions, and suspensions. These compositions are prepared by associating the active ingredient with a carrier and can be presented in different forms such as tablets, capsules, or liquid emulsions[4].
Patent Landscape Analysis
Defining Scope and Keywords
To analyze the patent landscape around U.S. Patent 5,565,473, one must define the scope of the analysis and identify relevant keywords. Key terms include "leukotriene antagonists," "unsaturated hydroxyalkylquinoline acids," and "Singulair®"[3].
Identifying Trends and Key Players
The analysis reveals that Merck Frosst Canada, Inc. is a significant player in the field of leukotriene antagonists. The patent filings indicate a strong focus on developing compounds for treating allergic and inflammatory conditions. Other key players in this domain include companies involved in similar pharmaceutical research and development[3].
Analyzing Citations and Evolution
The patent references several prior art documents, indicating the evolutionary path of the technology. Studying these citations helps in understanding the impact and development of the patented invention. For instance, the patent cites earlier patents related to similar chemical structures and their applications[4].
Legal and Regulatory Aspects
Patent Term Extension
The patent was eligible for a term extension under 35 U.S.C. § 156 due to the regulatory review period by the FDA. The extension period was calculated to be 430 days, extending the patent's expiration date from November 30, 2010, to February 3, 2012[1].
Reexamination and Infringement Suits
The patent underwent reexamination by the USPTO, which resulted in a non-final rejection of some claims due to nonstatutory obviousness-type double patenting. However, the claims were ultimately found patentable despite challenges from prior art references. The patent was also the subject of two patent infringement suits, known as "Singulair® I" and "Singulair® II," involving Teva Pharmaceuticals[5].
Competitive Landscape
Key Players and Innovations
The competitive landscape in the field of leukotriene antagonists is dominated by pharmaceutical companies like Merck and Teva. The analysis of patent filings reveals ongoing innovations and a competitive environment where companies are continually developing new compounds and formulations to treat allergic and inflammatory conditions[3].
Technological Trends
The patent landscape analysis indicates a trend towards more targeted and effective treatments for allergic reactions and inflammatory diseases. The use of specific chemical structures like unsaturated hydroxyalkylquinoline acids is a significant area of research and development[3].
Insights for Strategic Decisions
Evaluating Patent Strength
A patent landscape analysis helps in evaluating the strength of a patent portfolio. For U.S. Patent 5,565,473, the analysis shows that despite challenges, the patent remains a strong asset for Merck Frosst Canada, Inc. This insight is crucial for strategic decisions regarding research and development, licensing, and litigation[3].
Identifying Legal Vulnerabilities
The analysis also highlights potential legal vulnerabilities, such as the risk of reexamination and infringement suits. Understanding these vulnerabilities is essential for developing strategies to protect and enforce patent rights[3].
Key Takeaways
- Patent Coverage: U.S. Patent 5,565,473 covers specific chemical compounds and their compositions as leukotriene antagonists.
- Assignee and Inventors: The patent is assigned to Merck Frosst Canada, Inc., with multiple inventors from Canada.
- Legal and Regulatory: The patent underwent a term extension and reexamination, with significant legal battles over infringement.
- Competitive Landscape: The patent landscape is competitive, with ongoing innovations in treating allergic and inflammatory conditions.
- Strategic Insights: The analysis provides valuable insights for strategic decisions on research, development, and legal strategies.
FAQs
What is the main subject of U.S. Patent 5,565,473?
The main subject of U.S. Patent 5,565,473 is the use of unsaturated hydroxyalkylquinoline acids as leukotriene antagonists, specifically for the drug Singulair® (montelukast sodium).
Who is the assignee of U.S. Patent 5,565,473?
The assignee of U.S. Patent 5,565,473 is Merck Frosst Canada, Inc.
What was the outcome of the reexamination of U.S. Patent 5,565,473?
The reexamination resulted in a non-final rejection of some claims due to nonstatutory obviousness-type double patenting, but the claims were ultimately found patentable.
What is the significance of the patent term extension for U.S. Patent 5,565,473?
The patent term extension added 430 days to the original expiration date, extending it from November 30, 2010, to February 3, 2012.
What are the key trends in the patent landscape for leukotriene antagonists?
The key trends include ongoing innovations in developing targeted treatments for allergic and inflammatory conditions, with a focus on specific chemical structures like unsaturated hydroxyalkylquinoline acids.
Sources
- USPTO, "NoncE OF FINAL DETERMINATION - USPTO," May 31, 2000.
- DrugPatentWatch, "Details for Patent: 5565473 - DrugPatentWatch."
- Goldstein Patent Law, "How to Do Patent Landscape Analysis."
- Google Patents, "USOO5565473A - Unsaturated hydroxyalkylquinoline acids as leukotriene antagonists."
- WHDA Blog, "Merck Singulair® Claims Rejected : US PTO Litigation Alert™," September 3, 2009.
