United States Patent 9,326,945: A Detailed Analysis of Scope, Claims, and Patent Landscape
Introduction
United States Patent 9,326,945, titled "Apixaban Formulations," is a crucial patent held by Bristol-Myers Squibb Co. and Pfizer Inc. This patent is significant in the pharmaceutical industry, particularly in the context of anticoagulant medications. Here, we will delve into the scope, claims, and the broader patent landscape surrounding this invention.
Background of the Invention
The patent pertains to stable, reproducible, and bioequivalent pharmaceutical compositions of apixaban, an anticoagulant used to treat and reduce the risk of certain cardiovascular conditions. Previous formulations had issues with polymorphic stability and particle size distribution, which this patent aims to address[1][4].
Scope of the Patent
The patent covers specific formulations of apixaban that include crystalline apixaban particles with defined particle size specifications. Here are the key aspects of the scope:
- Particle Size: The patent specifies that the crystalline apixaban particles must have a D90 particle size equal to or less than about 89 μm. This ensures optimal bioavailability and reduces quality control challenges associated with larger particles[1][4].
- Dosage Forms: The patent claims various dosage forms, including tablets, where apixaban is present in predefined amounts (2.5 mg and 5 mg). These formulations must dissolve at least 77% within 30 minutes in a pH 6.8 phosphate buffer containing 0.05% sodium lauryl sulfate[1][4].
Claims of the Patent
The patent includes several claims that define the scope of the invention:
- Independent Claim 12: This claim recites the composition comprising crystalline apixaban particles with a D90 particle size equal to or less than about 89 μm. It also specifies the presence of a pharmaceutically acceptable diluent or carrier[2][4].
- Dependent Claims 21 and 22: These claims depend on independent claim 12 and add that the compositions comprise 2.5 mg or 5 mg of apixaban, respectively[2].
Patent Landscape and Litigation
The patent has been at the center of several legal disputes, particularly with generic pharmaceutical companies seeking to bring bioequivalent versions of apixaban to the market.
- Litigation in the US: Bristol-Myers Squibb and Pfizer have successfully defended the patent against infringement claims by generic companies such as Sigmapharm, Sunshine Lake Pharma, and Unichem. The US District Court for the District of Delaware and the US Court of Appeals for the Federal Circuit have upheld the validity of the patent, preventing generic versions from entering the US market until the patent expires in 2028[2][5].
- International Disputes: In the UK, Sandoz and Teva have challenged the validity of related European patents. While some of these patents have been invalidated, others remain under dispute, highlighting the ongoing legal battles in the global pharmaceutical landscape[5].
Technical Aspects and Innovations
The patent addresses several technical issues that were prevalent in earlier formulations of apixaban:
- Wet Granulation Process: The patent notes that formulations made using a wet granulation process, as well as those using large particles of apixaban, resulted in less than optimal exposures and quality control challenges. The current patent overcomes these deficiencies by specifying a more controlled particle size distribution[1].
- Polymorphic Stability: The patent ensures the stability of apixaban by defining specific crystalline forms, which is crucial for maintaining the efficacy and safety of the drug[1].
Impact on the Pharmaceutical Industry
The patent has significant implications for the pharmaceutical industry:
- Innovation and Competition: The patent's validity until 2028 limits competition from generic manufacturers, allowing Bristol-Myers Squibb and Pfizer to maintain market exclusivity for their product, Eliquis. This can impact the pricing and availability of the drug[5].
- Quality and Efficacy: The specified formulations ensure consistent quality and efficacy of apixaban, which is critical for patient safety and treatment outcomes[1][4].
Conclusion
United States Patent 9,326,945 is a pivotal patent in the pharmaceutical industry, particularly in the field of anticoagulant medications. Its scope and claims are carefully defined to ensure the stability, reproducibility, and bioequivalence of apixaban formulations. The ongoing legal disputes highlight the patent's significance and the efforts of pharmaceutical companies to protect their intellectual property.
Key Takeaways
- The patent covers specific formulations of apixaban with defined particle size specifications.
- It ensures optimal bioavailability and reduces quality control challenges.
- The patent has been upheld in US courts, preventing generic versions from entering the market until 2028.
- International disputes over related patents continue.
- The patent is crucial for maintaining the quality and efficacy of apixaban.
FAQs
Q: What is the main focus of United States Patent 9,326,945?
A: The main focus is on stable, reproducible, and bioequivalent pharmaceutical compositions of apixaban.
Q: What are the key specifications for the particle size of apixaban in this patent?
A: The crystalline apixaban particles must have a D90 particle size equal to or less than about 89 μm.
Q: Which companies are involved in the litigation over this patent?
A: Bristol-Myers Squibb, Pfizer, Sigmapharm, Sunshine Lake Pharma, Unichem, Sandoz, and Teva are involved in the litigation.
Q: What is the current legal status of the patent in the US?
A: The patent has been upheld by the US District Court for the District of Delaware and the US Court of Appeals for the Federal Circuit, preventing generic versions from entering the market until 2028.
Q: How does the patent impact the pharmaceutical industry?
A: It maintains market exclusivity for Bristol-Myers Squibb and Pfizer, ensuring consistent quality and efficacy of apixaban formulations.
Sources
- Justia Patents: Pharmaceutical composition of apixaban.
- Casetext: Bristol-Myers Squibb Co. v. Aurobindo Pharma U.S. Inc.
- SSRN: Patent Claims and Patent Scope.
- Google Patents: Apixaban formulations.
- Juve-Patent: Sandoz and Teva invalidate blockbuster apixaban patent and SPC.
