Understanding the Scope and Claims of United States Patent 5,541,170
Introduction
United States Patent 5,541,170, hereafter referred to as the '170 patent, is a pivotal patent in the pharmaceutical industry, particularly in the treatment of inflammatory diseases of the large intestine. This patent, owned by Medeva Pharma Suisse A.G. and associated with Warner Chilcott Pharmaceuticals, Inc., has a complex and extensive prosecution history that underscores its significance.
Background and Prosecution History
The '170 patent was issued on July 30, 1996, following a lengthy prosecution process that began with the filing of a patent application on July 28, 1982. This initial application was for a formulation that was as effective as SASP (Sulfasalazine) in treating ulcerative colitis. The inventors filed several continuation applications over the years, including No. 06/482,331, No. 06/735,727, No. 07/584,386, No. 07/858,449, and No. 08/032,167, before filing a divisional application (No. 08/401,696) on March 10, 1995, which ultimately led to the issuance of the '170 patent[1].
Key Inventions and Claims
The '170 patent revolves around a specific formulation of mesalamine (5-ASA) designed to treat inflammatory diseases of the large intestine, such as ulcerative colitis and Crohn's disease. The innovation lies in the coating and dosage form that ensures the mesalamine is delivered directly to the colon without leaching out prematurely in the intestinal tract.
Coating and Dosage Form
The patentees developed a coating comprised solely of Eudragit S, a polymer that ensures the mesalamine is released specifically in the colon. This is in contrast to prior art that used mixtures of Eudragit S and Eudragit L, which were insufficient to prevent premature release of the active ingredient[1].
Organ Specificity
A critical aspect of the '170 patent is the high organ specificity of the coating and dosage form. The patentees emphasized that their formulation ensures mesalamine is "dumped" into the colon rather than being consistently released in small amounts throughout the intestinal tract[1].
Prior Art and Distinctions
Throughout the prosecution history, the patentees distinguished their invention from several types of prior art. One notable prior art involved coatings made from mixtures of Eudragit S and Eudragit L, which were too thin to prevent the 5-ASA from leaching out before reaching the colon. The patentees' use of a thicker coating made solely of Eudragit S was a key differentiator[1].
Divisional Applications and Related Patents
The '170 patent was part of a larger patent family that included another significant patent, U.S. Patent No. 5,541,171 (the '171 patent). The '171 patent was issued from a continuation application (No. 08/448,300) that was filed after the divisional application for the '170 patent. A key difference between the two patents is that the '171 patent expressly excludes coating mixtures of Eudragit S and Eudragit L, whereas the '170 patent does not[1].
Patent Landscape and Litigation
The '170 patent has been involved in significant litigation, particularly in the case of Medeva Pharma Suisse A.G. v. Par Pharmaceutical, Inc.. In this case, the defendants submitted an Abbreviated New Drug Application (ANDA) to market a generic version of the Asacol® drug product, which is covered by the '170 patent. The plaintiffs alleged patent infringement, highlighting the importance of the '170 patent in protecting their intellectual property[1][4].
Restriction Requirements and Divisional Applications
The extensive prosecution history of the '170 patent includes the filing of divisional applications due to restriction requirements imposed by the Patent and Trademark Office (PTO). When an application includes claims to independent and distinct inventions, the PTO may require the application to be restricted to one of the inventions. The patentees filed a divisional application to pursue broader claims that were ultimately incorporated into the '170 patent[1].
Economic and Research Implications
The '170 patent is part of a broader dataset of patent claims and scope measurements maintained by the USPTO. The Patent Claims Research Dataset provides detailed information on claims from U.S. patents granted between 1976 and 2014, including statistics and measures of patent scope. This dataset is crucial for understanding the economic and research implications of patents like the '170 patent[3].
Industry Impact
The '170 patent has had a significant impact on the pharmaceutical industry, particularly in the development and marketing of drugs for inflammatory diseases of the large intestine. The unique formulation and delivery system protected by this patent have set a standard for efficacy and specificity in treating conditions like ulcerative colitis and Crohn's disease.
Expert Insights
Industry experts highlight the importance of such patents in driving innovation and ensuring that pharmaceutical companies can invest in research and development without fear of immediate generic competition. As noted by Alan C. Marco and Joshua D. Sarnoff in their work on patent claims and scope, "Patents play a crucial role in incentivizing innovation by providing temporary monopolies to inventors"[3].
Conclusion
The '170 patent is a testament to the complex and often lengthy process of patent prosecution and the importance of intellectual property protection in the pharmaceutical industry. Its unique claims and formulation have set a benchmark for treating inflammatory diseases of the large intestine.
Key Takeaways
- Innovation in Formulation: The '170 patent protects a unique formulation of mesalamine designed to treat inflammatory diseases of the large intestine.
- Coating and Dosage Form: The use of Eudragit S as a coating ensures the mesalamine is delivered specifically to the colon.
- Prosecution History: The patent was issued after a lengthy prosecution process involving multiple continuation and divisional applications.
- Litigation: The patent has been involved in significant litigation to protect against generic competition.
- Industry Impact: The patent has set a standard for efficacy and specificity in treating conditions like ulcerative colitis and Crohn's disease.
FAQs
Q: What is the main innovation protected by the '170 patent?
A: The main innovation is a unique formulation of mesalamine (5-ASA) designed to treat inflammatory diseases of the large intestine, specifically ensuring the drug is delivered directly to the colon.
Q: Why was the '170 patent involved in extensive litigation?
A: The patent was involved in litigation due to generic drug manufacturers submitting ANDAs to market generic versions of the Asacol® drug product, which is covered by the '170 patent.
Q: What is the significance of the coating in the '170 patent?
A: The coating, made solely of Eudragit S, ensures that the mesalamine is released specifically in the colon and does not leach out prematurely in the intestinal tract.
Q: How does the '170 patent differ from the '171 patent?
A: The '171 patent expressly excludes coating mixtures of Eudragit S and Eudragit L, whereas the '170 patent does not.
Q: What is the economic impact of patents like the '170 patent?
A: Patents like the '170 patent provide temporary monopolies that incentivize innovation and investment in research and development within the pharmaceutical industry.
Sources
- Medeva Pharma Suisse A.G. v. Par Pharm., Inc. - Casetext
- United States Patent 7928092 - Patent Images
- Patent Claims Research Dataset - USPTO
- Medeva Pharma Suisse A.G. v. PAR Phamaceutical Inc. - Law.com
- Court Report - Patent Docs
