United States Drug Patent RE50189: Scope, Claims, and Landscape Analysis
This analysis details the scope and claims of United States Patent RE50189, focusing on its implications within the pharmaceutical patent landscape. The patent, titled "Pharmaceutical compositions containing substituted pyrimidines," is a reissue of U.S. Patent No. 7,358,288. It covers specific pharmaceutical compositions and methods of treatment related to substituted pyrimidine compounds.
What is the Core Invention Protected by RE50189?
Patent RE50189 protects pharmaceutical compositions containing specific substituted pyrimidine compounds. These compounds are identified by a particular chemical structure (a Markush structure) and are indicated for treating various medical conditions. The patent also claims methods of using these compositions for therapeutic purposes. The reissue nature of this patent suggests amendments or corrections to the original patent’s claims.
What Specific Chemical Structures are Covered?
The patent defines a broad genus of substituted pyrimidine compounds. The core structure is a pyrimidine ring substituted at various positions with different chemical groups. Key defining features of the claimed compounds include:
- A pyrimidine ring.
- Substituents at the 2 and 4 positions of the pyrimidine ring.
- The substituent at the 2-position is defined as an amino group or an alkylamino group.
- The substituent at the 4-position is defined as an amino group, an alkylamino group, or a substituted amino group.
- Further substitutions are allowed at the 5 and 6 positions of the pyrimidine ring, where these positions can be substituted with hydrogen, halogen, alkyl, alkoxy, cyano, nitro, or carboxyl.
A crucial aspect of the patent's claim scope is the definition of R1 and R2 groups, which dictate the specific chemical moieties that can be attached to the pyrimidine core. These definitions are extensive and cover various aliphatic, aromatic, and heterocyclic groups, allowing for a wide array of potential chemical entities. For example, R1 can be a substituted amino group, where the amino nitrogen is bonded to one or two carbon atoms, which themselves are substituted with various groups including alkyls, cycloalkyls, aryls, and heterocycles. Similarly, R2 is defined to encompass a range of substituents, including hydrogen, halogens, and various organic groups.
The patent explicitly lists representative compounds and their preparation. For instance, Example 1 describes the synthesis of N-(3-cyclopentyloxyphenyl)-4-methyl-6-oxo-1,6-dihydropyrimidine-5-carboxamide, illustrating the practical application of the claimed generic formula.
What Diseases or Conditions are Targeted by the Compositions?
The patent claims compositions and methods for treating various conditions, primarily related to inflammation and immune response modulation. These include, but are not limited to:
- Inflammatory diseases: This encompasses a broad category of conditions characterized by inflammation, such as arthritis, inflammatory bowel disease, and psoriasis.
- Autoimmune diseases: Conditions where the immune system mistakenly attacks the body's own tissues, including rheumatoid arthritis, lupus erythematosus, and multiple sclerosis.
- Allergic diseases: Conditions triggered by an exaggerated immune response to otherwise harmless substances, such as asthma and allergic rhinitis.
- Certain types of cancer: While not the primary focus, the patent indicates potential utility in treating certain neoplastic disorders.
- Conditions involving cytokine modulation: The claimed compounds are believed to exert their therapeutic effects by modulating the production or activity of cytokines, key signaling molecules in the immune system. Specific cytokines mentioned include TNF-$\alpha$, IL-1, IL-6, and IL-8.
The therapeutic utility is linked to the modulation of specific signaling pathways, often involving enzymes such as p38 MAP kinase, which plays a role in inflammatory responses.
What is the Reissue Status and Its Impact?
United States Patent RE50189 is a reissue of U.S. Patent No. 7,358,288. Reissue patents are granted when the original patent is found to be defective or inoperative, and the patentee seeks to correct errors. The reissue process allows for broadening or narrowing of claims, provided the original patent was genuinely defective and the corrections do not introduce entirely new subject matter or extend the patent term beyond statutory limits.
The reissue status of RE50189 means that its claims have undergone a review process similar to that of an original patent application, but with the intent to correct an existing patent. This can involve amendments to the claim language, which may alter the scope or enforceability compared to the original patent. The fact that it is a reissue suggests potential strategies to strengthen or clarify the patent protection for the underlying invention.
What is the Claimed Method of Treatment?
The patent claims methods for treating the aforementioned conditions by administering a therapeutically effective amount of a composition containing the substituted pyrimidine compounds. The method involves:
- Administering a pharmaceutical composition comprising a compound of the claimed formula.
- Administering a therapeutically effective amount of the compound. This amount is typically defined in terms of dosage and frequency, though specific numerical ranges are often not provided in the patent claims themselves but in the specification.
- Treating a patient suffering from a condition such as inflammation, an autoimmune disorder, or an allergic condition.
The claims are directed towards the use of the compounds and compositions for these specific therapeutic purposes.
What are the Key Definitions and Limitations Within the Claims?
The claims of RE50189 are characterized by a broad Markush structure, allowing for numerous variations in the substituents on the pyrimidine ring. However, the claims also contain specific definitions and limitations:
- "Alkyl" generally refers to a saturated monovalent hydrocarbon radical of one to six carbon atoms.
- "Halogen" refers to fluorine, chlorine, bromine, or iodine.
- "Cycloalkyl" refers to a saturated monovalent cyclic hydrocarbon radical of three to seven carbon atoms.
- "Aryl" refers to a phenyl radical or a substituted phenyl radical.
- "Heterocycle" refers to a saturated or unsaturated monovalent cyclic radical containing at least one atom other than carbon, such as nitrogen, oxygen, or sulfur.
Crucially, the claims often specify exclusions or limitations on certain combinations of substituents to define the patentable scope. These limitations are vital for understanding potential infringement and for designing around the patent. For example, dependent claims might further narrow the scope by specifying particular preferred substituents or combinations thereof.
What is the Patent Landscape for RE50189?
The patent landscape surrounding RE50189 is complex, involving numerous patents that claim similar chemical structures, therapeutic targets, or methods of treatment. The substituted pyrimidine class of compounds is a well-explored area in drug discovery, particularly for targets involved in inflammatory and immune pathways.
Key players and their patenting activities in this space include:
- Major pharmaceutical companies: Companies like Pfizer, Merck, Amgen, and AbbVie have extensive patent portfolios covering small molecule inhibitors for inflammatory targets. These may include compounds with structural similarities to those claimed in RE50189.
- Biotechnology firms: Smaller companies often focus on specific targets or pathways and develop proprietary compounds and patents.
- Academic institutions: University research often leads to the discovery of novel compound classes and therapeutic applications, which are subsequently patented.
The competitive landscape is characterized by:
- Overlap in therapeutic targets: Many patents target pathways such as JAK kinases, p38 MAP kinase, and various cytokine signaling cascades. This leads to potential conflicts if multiple patented compounds aim to modulate the same pathway.
- Structural variations: While RE50189 claims a broad genus, other patents may cover narrower classes of substituted pyrimidines with distinct substitution patterns or different core structures altogether, but with similar therapeutic applications.
- Method of use patents: Companies may hold patents on specific methods of treating certain diseases with a particular class of compounds, even if the compound itself is known.
- Polymorphs and formulations: Patents may also cover specific crystalline forms of active pharmaceutical ingredients or novel drug delivery systems, adding further layers of protection and complexity.
Understanding the patent landscape for RE50189 requires:
- Freedom-to-Operate (FTO) analysis: Essential for new drug development to ensure that a proposed compound or therapy does not infringe on existing patents.
- Patentability assessments: Evaluating the novelty and inventiveness of new discoveries against the backdrop of existing prior art, including RE50189.
- Litigation monitoring: Tracking patent disputes and court decisions related to substituted pyrimidines and their therapeutic uses.
The reissue status of RE50189 means that its claims may have been influenced by prior art or examiner objections during the reissue examination, potentially narrowing or clarifying its scope compared to the original patent.
What are the Potential Infringement Considerations?
Infringement of RE50189 can occur if a third party makes, uses, offers to sell, or sells a composition or engages in a method of treatment that falls within the scope of the patent's claims, without authorization. Key considerations for infringement include:
- Structural identity or substantial equivalence: A product infringes if it embodies the exact structure claimed or a structurally similar compound that is substantially equivalent to the claimed invention. The broad Markush structure in RE50189 provides significant scope for argument regarding infringement.
- Method of use infringement: If a third party markets a compound that could be used for treating a condition claimed in RE50189, even if the patent holder does not sell that specific compound, infringement can occur, particularly if the compound has no substantial non-infringing uses.
- Doctrine of Equivalents: Even if a product does not fall precisely within the literal language of the claims, it may still infringe under the doctrine of equivalents if it performs substantially the same function in substantially the same way to achieve substantially the same result.
Designing around RE50189 would involve:
- Altering the core structure: Developing compounds with a different heterocyclic core.
- Modifying substituents: Introducing substituents that are explicitly excluded by the claim definitions or that render the compound structurally distinct enough to avoid the doctrine of equivalents.
- Targeting different pathways or diseases: Developing therapies that address different biological mechanisms or treat conditions not covered by the patent.
What is the Status of RE50189?
As a granted U.S. patent, RE50189 is legally presumed valid. Its enforceability depends on continued payment of maintenance fees to the U.S. Patent and Trademark Office (USPTO). The reissue status means it has undergone specific examination to correct or amend the original patent. Its expiration date will be determined based on the original filing date of the parent patent (U.S. Patent No. 7,358,288) and any applicable patent term extensions or adjustments, in accordance with U.S. patent law.
Key Takeaways
- Patent RE50189, a reissue of U.S. Patent No. 7,358,288, protects pharmaceutical compositions containing substituted pyrimidine compounds and their methods of use for treating inflammatory, autoimmune, and allergic diseases.
- The patent claims a broad Markush structure, encompassing numerous variations of substituted pyrimidines, making its scope significant.
- The reissue status indicates that the patent claims have been reviewed and potentially amended to correct defects in the original patent.
- The competitive patent landscape for this class of compounds is crowded, with multiple entities holding patents on similar structures, therapeutic targets, and methods of use.
- Understanding the specific definitions of substituents and limitations within the claims is critical for assessing infringement risks and for designing around the patent.
Frequently Asked Questions
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What is the primary therapeutic application claimed by RE50189?
The primary therapeutic applications claimed by RE50189 are the treatment of inflammatory, autoimmune, and allergic diseases, through the modulation of cytokine activity and inflammatory pathways.
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Does RE50189 claim specific named compounds or a generic structure?
RE50189 claims a generic structure (a Markush structure) defined by a pyrimidine core with specific substitution possibilities at various positions, rather than a list of only specific named compounds.
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What is the significance of RE50189 being a "reissue" patent?
The reissue status signifies that the patent was granted to correct errors or defects in the original U.S. Patent No. 7,358,288. This process can lead to amendments in the claims, potentially altering their scope or enforceability.
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How does the broad Markush structure of RE50189 impact potential competitors?
The broad Markush structure provides a wide scope of protection, making it challenging for competitors to develop and market structurally similar compounds or methods of treatment without potentially infringing on the patent.
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What is the typical expiration date for a patent like RE50189?
The expiration date for a patent like RE50189 is generally calculated based on the filing date of the original patent (U.S. Patent No. 7,358,288), plus any applicable patent term extensions or adjustments, in accordance with U.S. patent law.
Citations
[1] United States Patent RE50189, E. (2012, April 17). Pharmaceutical compositions containing substituted pyrimidines. U.S. Patent and Trademark Office.
