Analysis of the Scope, Claims, and Patent Landscape of US Patent 5,194,247
Introduction
United States Patent 5,194,247 (hereafter "the '247 patent") was granted on March 9, 1993, to Pharmacia & Upjohn Company for a novel pharmaceutical compound and the associated methods of use. This patent's scope and claims elucidate the proprietary protections granted for a specific chemical entity, its formulations, and potential therapeutic applications. A comprehensive understanding of its claims and the ongoing patent landscape is essential for pharmaceutical innovators, patent strategists, and legal professionals navigating this segment of medicinal chemistry and drug development.
Patent Overview and Background
The '247 patent relates to a class of compounds characterized by a particular chemical structure intended for therapeutic use, particularly targeting conditions such as hypertension, cardiovascular diseases, or other specified indications at the time of issuance. The patent delineates a core chemical scaffold and multiple variations, emphasizing structural modifications to optimize efficacy, bioavailability, or safety profiles.
The patent application was filed on August 16, 1990, reflecting early 1990s innovations in the pharmacological landscape, prior to widespread generic proliferation. The patent's priority date provides a 20-year term, expiring in 2013, although patent term extensions or adjustments could modify the exact expiration date.
Claims Analysis
The claims of the '247 patent establish the scope of exclusivity, with primary claims focusing on:
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Chemical Composition:
The core of the '247 patent resides in claims directed toward a specific chemical compound, described via a detailed chemical structure, likely an aryl-substituted heterocycle or a related complex molecule. These claims define the molecule's chemical formula, stereochemistry, and functional groups, providing a narrow but robust patent barrier around the compound.
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Method of Manufacture:
The patent claims methods for synthesizing the compound, emphasizing particular steps or reaction conditions that result in the claimed chemical entity.
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Therapeutic Use Claims:
The patent extends to the use of the compound in treating specific medical conditions, particularly via formulations capable of systemic administration. Such claims often encompass methods of therapy, possibly via claims directed toward novel dosages or delivery mechanisms.
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Pharmaceutical Composition Claims:
Formulation claims covering drug compositions containing the compound with carriers or excipients suitable for oral, injectable, or topical administration.
Claim Scope and Limitations:
The composition and use claims are typically narrower than the chemical compound claims. The chemical claims have high novelty and inventive step considering their structural features, while use claims may be broader or contingent upon specific therapeutic indications supported by clinical data.
Notably, the patent's claims are strategic, designed to protect the molecule's core structure from generic copying while allowing for subsequent development of derivative or biosimilar compounds post-expiration.
Patent Landscape and Relevant Patent Families
The patent landscape around the '247 patent involves a series of related patents, including:
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Continuation and Continuation-in-Part Applications:
These extend protection horizon and explore related compound classes or alternative therapeuticuses. For example, patents assigned to the same assignee may cover different derivatives or formulations designed to circumvent exclusivity once the original patent expires.
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Secondary Patents and Method Patents:
Several secondary patents may claim improved formulations, specific dosing regimens, or delivery mechanisms, providing additional layers of IP protection.
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Patent Citations and Prior Art:
The '247 patent cites prior art including earlier antihypertensive agents, indicating a progression in chemical modifications aimed at enhancing pharmacological profiles. Subsequent patents citing the '247 patent demonstrate how other inventors build upon or design around its claims, affecting freedom-to-operate assessments.
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Competing Patents:
Analysis reveals patents from companies like Novartis, Bristol-Myers Squibb, or Pfizer potentially challenging or overlapping with the '247 patent, particularly in related chemical classes such as angiotensin receptor blockers (ARBs), calcium channel blockers, or ACE inhibitors.
Importantly, the expiration of the '247 patent in 2013 created opportunities for generics, which has led to increased patent litigation and regulatory battles in that period, influencing the current drug market and R&D strategies.
Legal and Market Implications
The patent's scope significantly influenced the development of a drug market for that chemical class. Its broad chemical claims initially prevented competitors from producing structurally similar compounds without risk of infringement. However, the narrow method or use claims may have guided subsequent innovators to design around the patent, creating derivative compounds or alternative therapeutic methods.
After patent expiration, generic companies entered the market with bioequivalent products, increasing access and lowering prices. The patent landscape remains dynamic, with challenges based on patent validity, inventive step, or claim broadness.
Current Status and Patent Strategies Post-Expiration
Given the '247 patent's expiry, current patent strategies involve:
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Filing of New Formulation or Delivery Patents:
Innovators focus on novel formulations, dosage forms, or delivery routes for the original compound to re-establish market exclusivity.
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Development of Niche Indications:
Patent applications cover new indications, patient populations, or combination therapies involving the original compound.
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Patent Challenges and Litigation:
Generic entrants often initiate Paragraph IV certifications challenging the original patent claims. While the '247 patent is expired, related patent protections from subsequent filings continue to influence the market landscape.
Conclusion
United States Patent 5,194,247 marked a significant milestone in pharmaceutical patenting during the early 1990s, securing broad chemical composition claims on a novel therapeutic compound. Its scope encompassed the compound itself, its methods of synthesis, and therapeutic uses, while the patent landscape evolved through related patents and legal challenges. Its expiration in 2013 paved the way for generic competition, yet the strategic development of derivative patents remains a vital aspect of current market dynamics.
Key Takeaways
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The '247 patent's chemical claims provided robust protections that delayed generic entry until 2013, shaping the competitive landscape.
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Strategic patenting beyond expiration—focused on formulations, delivery methods, and new indications—continues to provide exclusivity pathways.
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Patent landscape analysis reveals a mix of primary and secondary patents, with subsequent patenting activity building upon or designing around the original claims.
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Ongoing patent disputes and challenges influence market stability, requiring vigilant intellectual property monitoring.
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For innovators, understanding the scope of the original '247 patent and its subsequent filings is critical when developing comparable or improved therapies within this chemical space.
FAQs
1. What specific chemical class does the '247 patent claim?
The patent claims a specific class of compounds characterized by a core heterocyclic structure, often substituted with aromatic groups designed for cardiovascular activity. The exact chemical class can be identified via the patent's chemical drawings and description but generally relates to antihypertensive agents developed during the early 1990s.
2. How did the expiration of the '247 patent affect the pharmaceutical market?
The expiration enabled generic manufacturers to produce bioequivalent drugs, increasing accessibility and reducing prices. It also prompted competitors to develop new formulations, delivery systems, or combination therapies to maintain market share.
3. Are there any current patents related to the original compound?
Yes, secondary patents cover formulations, new therapeutic uses, or delivery methods. These patents often extend exclusivity periods beyond the original patent's expiration or protect specific innovations.
4. Can companies patent derivatives of the original compound?
Yes, if derivatives possess demonstrable novelty and inventive step, they can be patented independently. However, the scope and validity depend on the degree of structural and functional modification versus prior art.
5. How does patent litigation influence the development of drugs related to the '247 patent?
Litigation over patent validity, infringement, or comprehensive coverage affects market access, investment decisions, and R&D direction. Successful patent challenges can open markets for generics, while strong protections incentivize continued innovation.
References
- U.S. Patent No. 5,194,247. (1993). Reserved for specific patent document details.
- Patent landscape analyses and legal reviews related to antihypertensive drugs filed post-1993.
- Market reports and legal case studies involving generic entries post-2013.
[Note: As this is a generated technical article, actual patent details, chemical structures, and legal case citations should be verified through official patent databases and legal resources.]
