Understanding the Scope and Claims of United States Patent 7,265,221
Introduction
United States Patent 7,265,221, titled "Pyrrolo[2,3-d]pyrimidine compounds," is a significant patent in the field of pharmaceuticals, particularly in the development of treatments for various medical conditions. This patent, granted to Pfizer, involves compounds that inhibit specific protein kinases, such as Janus Kinase 3 (JAK3), which are crucial in the treatment of autoimmune diseases and other disorders.
Patent Overview
The patent 7,265,221 was granted on September 4, 2007, and it expired on December 8, 2020, as indicated by the FDA's Orange Book[1].
Claims and Scope
Independent and Dependent Claims
The patent includes a series of independent and dependent claims that define the scope of the invention. Independent claims are broad and stand alone, while dependent claims narrow down the scope by adding specific limitations to the independent claims.
- Independent Claims: These claims define the core invention, including the chemical structure of the pyrrolo[2,3-d]pyrimidine compounds and their use in treating or preventing disorders such as organ transplant rejection and autoimmune diseases[4].
- Dependent Claims: These claims specify various aspects of the compounds, such as the presence of specific functional groups, the configuration of double bonds (cis and trans), and the inclusion of all conformational isomers and stereoisomers[4].
Claim Language and Scope Metrics
The scope of the patent can be measured using metrics such as independent claim length and independent claim count. Research has shown that narrower claims, as indicated by shorter independent claim lengths and fewer independent claims, are associated with a higher probability of grant and a shorter examination process[3].
Chemical Structure and Variants
The patent describes a wide range of chemical variants within the pyrrolo[2,3-d]pyrimidine class.
- Functional Groups: The compounds may include various functional groups such as alkyl, amino, alkylamino, trifluoromethyl, and acylamino groups[4].
- Configurations and Isomers: The compounds can exist in different configurations, including cis and trans isomers, and various enantiomeric and diastereomeric forms. The patent also encompasses tautomers and mixtures thereof[4].
Pharmaceutical Applications
The patent covers the use of these compounds in pharmaceutical compositions and methods of treatment.
- Protein Kinase Inhibition: The compounds are designed to inhibit protein kinases, particularly JAK3, which is involved in the signaling pathways of immune cells[4].
- Therapeutic Uses: The patent includes methods for treating or preventing disorders such as organ transplant rejection, autoimmune diseases, and other conditions that can be managed through the inhibition of protein kinases[4].
Patent Landscape and Exclusivity
Patent Expiration and Generic Entry
The patent 7,265,221 expired on December 8, 2020, which allowed generic versions of the drug to enter the market. However, other exclusivities, such as the I-761 and I-780 exclusivities related to the reference listed drug (RLD) Xeljanz, delayed the final approval of generic versions until May 30, 2021[1].
Litigation and Certifications
The approval process for generic versions involved paragraph IV certifications under the FD&C Act, stating that the patents were invalid, unenforceable, or would not be infringed. Litigation was initiated but later dismissed, allowing for the eventual approval of generic versions[1].
Economic and Innovation Impact
Patent Quality and Scope
The debate over patent quality and scope is relevant here. Broader patents can lead to increased licensing and litigation costs, potentially diminishing innovation incentives. However, the metrics used to measure patent scope, such as independent claim length and count, suggest that this patent was carefully crafted to balance breadth and specificity[3].
Forward Citations and Maintenance Payments
The patent's impact can also be gauged by its forward citations and maintenance payments. Patents with narrower claims tend to have more forward citations and higher maintenance payments, indicating their value and relevance in the field[3].
Conclusion
United States Patent 7,265,221 is a critical patent in the pharmaceutical industry, particularly in the development of treatments for autoimmune diseases and organ transplant rejection. The patent's scope, defined by its claims, encompasses a broad range of pyrrolo[2,3-d]pyrimidine compounds and their therapeutic applications. The expiration of this patent and related exclusivities have paved the way for generic versions, highlighting the dynamic nature of the patent landscape.
Key Takeaways
- Patent Scope: Defined by independent and dependent claims, including chemical structure and therapeutic uses.
- Chemical Variants: Includes various functional groups, configurations, and isomers.
- Pharmaceutical Applications: Involves inhibition of protein kinases, particularly JAK3.
- Patent Expiration: Expired on December 8, 2020, with generic entry delayed by other exclusivities.
- Economic Impact: Metrics like claim length and count indicate the patent's balance between breadth and specificity.
FAQs
Q1: What is the main subject of United States Patent 7,265,221?
A1: The main subject is pyrrolo[2,3-d]pyrimidine compounds and their use in treating or preventing various medical conditions.
Q2: What is the significance of JAK3 inhibition in this patent?
A2: JAK3 inhibition is crucial as it targets a specific enzyme involved in immune cell signaling pathways, making it effective for treating autoimmune diseases and organ transplant rejection.
Q3: When did the patent 7,265,221 expire?
A3: The patent expired on December 8, 2020.
Q4: What delayed the approval of generic versions of the drug?
A4: The approval was delayed by other exclusivities related to the reference listed drug (RLD) Xeljanz, specifically the I-761 and I-780 exclusivities, until May 30, 2021.
Q5: How can the scope of a patent be measured?
A5: The scope can be measured using metrics such as independent claim length and independent claim count, which provide insights into the patent's breadth and specificity.
Sources
- FDA Approval Letter for Tofacitinib Tablets: U.S. Food & Drug Administration.
- Patent Claims Research Dataset: USPTO.
- Patent Claims and Patent Scope: SSRN.
- US7265221B2 - Pyrrolo[2,3-d]pyrimidine compounds: Google Patents.
