Analyzing the Scope and Claims of United States Patent 6,028,071
Introduction
United States Patent 6,028,071, titled "Purified compositions of 10-propargyl-10-deazaaminopterin and methods of using same in the treatment of tumors," is a significant patent in the field of oncology. This patent, granted to the inventors, details the preparation, purification, and medical use of 10-propargyl-10-deazaaminopterin, also known as pralatrexate.
Background of the Invention
Pralatrexate is an anti-cancer drug that belongs to the class of antifolates. It is designed to inhibit dihydrofolate reductase (DHFR), an enzyme crucial for the synthesis of nucleic acids, thereby inhibiting the growth of cancer cells[4].
Claims of the Patent
The patent includes several key claims that define its scope:
Composition Claims
- The patent claims purified compositions of 10-propargyl-10-deazaaminopterin, which are highly purified and have specific characteristics that enhance their efficacy and stability[4].
Method Claims
- Methods for preparing and purifying 10-propargyl-10-deazaaminopterin are detailed. These methods include crystallization, chromatography, and other purification techniques to achieve high purity levels[4].
Use Claims
- The patent claims the use of these purified compositions in the treatment of various tumors, including lung neoplasms, breast cancer, and other neoplastic diseases[4].
Scope of the Patent
The scope of the patent is defined by the breadth and specificity of its claims.
Independent Claims
- Independent claims are those that stand alone and do not depend on other claims. In this patent, independent claims cover the purified compositions and methods of preparation, as well as the therapeutic uses of these compositions[4].
Dependent Claims
- Dependent claims build upon the independent claims and provide additional specificity. For example, dependent claims might specify particular methods of purification or specific types of tumors that can be treated[4].
Patent Landscape
The patent landscape surrounding US 6,028,071 involves several key aspects:
Related Patents
- Other patents related to pralatrexate and its intermediates, such as the processes for preparing and purifying these compounds, are also relevant. For instance, patents like WO 2013/096800 A1 detail processes for preparing and purifying pralatrexate intermediates, which are crucial for the overall synthesis of pralatrexate[1].
Competing Technologies
- The patent landscape also includes competing technologies and drugs in the antifolate class. Other antifolates like methotrexate and pemetrexed are used in cancer treatment, and their patents and claims need to be considered in the context of US 6,028,071[4].
Patent Scope Metrics
To analyze the scope of this patent, metrics such as independent claim length and independent claim count can be used, as suggested by research on patent scope.
Independent Claim Length
- Longer independent claims often indicate narrower and more specific claims, which can be beneficial for patent validity and enforcement[3].
Independent Claim Count
- A higher number of independent claims can indicate a broader scope, but it also increases the complexity and potential for overlap with other patents[3].
Examination Process and Patent Scope
The examination process for this patent would have involved narrowing the scope of the claims to ensure clarity, specificity, and non-obviousness. Research indicates that the examination process tends to narrow the scope of patent claims, which can affect the patent's breadth and enforceability[3].
Therapeutic Uses and Clinical Implications
The patent's claims on the therapeutic uses of pralatrexate are significant. Pralatrexate is used in the treatment of various cancers, including T-cell lymphoma, and its purified compositions are crucial for ensuring efficacy and minimizing side effects.
Purification and Stability
The purification methods claimed in the patent are critical for the stability and efficacy of pralatrexate. High purity levels are essential for ensuring consistent therapeutic outcomes and minimizing adverse effects[4].
Crystalline Forms and Salts
The patent also covers crystalline forms and salts of pralatrexate, which can have advantageous properties such as improved solubility, stability, and handling characteristics. These forms are important for pharmaceutical formulation and administration[1].
Key Takeaways
- Purified Compositions: The patent covers highly purified compositions of 10-propargyl-10-deazaaminopterin.
- Methods of Preparation: Detailed methods for preparing and purifying the drug are included.
- Therapeutic Uses: The patent claims the use of these compositions in treating various tumors.
- Patent Scope: The scope is defined by independent and dependent claims, with metrics like claim length and count providing insights into its breadth.
- Patent Landscape: The patent is part of a broader landscape involving related patents and competing technologies.
FAQs
Q: What is the main compound described in US Patent 6,028,071?
A: The main compound is 10-propargyl-10-deazaaminopterin, also known as pralatrexate.
Q: What are the therapeutic uses of pralatrexate according to the patent?
A: The patent claims the use of pralatrexate in the treatment of various tumors, including lung neoplasms and breast cancer.
Q: How is pralatrexate purified according to the patent?
A: The patent details methods including crystallization, chromatography, and other purification techniques to achieve high purity levels.
Q: What are the advantages of the crystalline forms and salts of pralatrexate?
A: These forms can have improved solubility, stability, and handling characteristics, which are important for pharmaceutical formulation and administration.
Q: How does the examination process affect the scope of the patent?
A: The examination process tends to narrow the scope of patent claims, ensuring clarity, specificity, and non-obviousness.
Cited Sources
- WO 2013/096800 A1 - World Intellectual Property Organization International Bureau.
- USPTO Patent Claims Research Dataset - United States Patent and Trademark Office.
- Patent Claims and Patent Scope - SSRN.
- US6028071A - Google Patents.
