United States Patent 6,774,122: A Detailed Analysis of Scope, Claims, and Patent Landscape
Introduction
United States Patent 6,774,122, titled "Formulation," is a significant patent in the pharmaceutical industry, particularly in the context of sustained release formulations. This patent, related to the drug fulvestrant, is crucial for understanding the development and commercialization of pharmaceutical products.
Background of Fulvestrant
Fulvestrant is a selective estrogen receptor degrader (SERD) used primarily in the treatment of hormone receptor-positive metastatic breast cancer. The drug's efficacy and delivery method are critical aspects of its therapeutic success.
Patent Overview
Publication and Legal Status
The patent was published on August 10, 2004, and has since expired. The legal status indicates that the patent is no longer in force, which is important for generic drug manufacturers and other stakeholders[1].
Claims and Scope
Primary Claims
The patent primarily covers a novel sustained release pharmaceutical formulation adapted for administration by injection. This formulation contains the compound fulvestrant, along with specific solvents and excipients designed to enhance its solubility and stability.
Key Components
- Fulvestrant: The active pharmaceutical ingredient, a SERD used in breast cancer treatment.
- Solvents and Excipients: The formulation includes a non-aqueous ester solvent (such as benzyl benzoate, ethyl oleate, isopropyl myristate, or isopropyl palmitate) and an alcohol (like benzyl alcohol), which are miscible in castor oil. Polysorbate 80 and an antioxidant are also included to stabilize the formulation[1][5].
Formulation Characteristics
The patent specifies that the formulation should achieve a concentration of at least 50 mg/mL of fulvestrant. This is achieved by using a combination of solvents that ease the solubilization of fulvestrant into the desired concentration[5].
Patent Landscape
Related Patents
Several other patents are closely related to U.S. Patent 6,774,122, including U.S. Patents 7,456,160, 8,329,680, and 8,466,139. These patents also pertain to fulvestrant formulations and their components, such as the use of non-aqueous ester solvents and specific excipients[4][5].
IPC Classifications
The International Patent Classification (IPC) for these patents often falls under classes such as C07D (heterocyclic compounds), which is a dominant category in pharmaceutical patent applications. Other relevant IPC classes include A61P (therapeutic activity of chemical compounds or medicinal preparations) and C07K (peptides)[3].
Litigation and Regulatory Aspects
Patent Infringement Actions
The patent has been involved in several patent infringement actions. For instance, AstraZeneca Pharmaceuticals LP filed a patent infringement action against Fresenius Kabi USA, LLC, related to the generic version of fulvestrant. This led to a consent judgment and a settlement agreement that restricted Fresenius Kabi from manufacturing, using, or selling the generic product until the patents expired[4].
FDA Approval and Regulatory Considerations
The FDA's approval process for generic versions of fulvestrant was significantly influenced by this patent. The FDA's interpretation of the consent judgment allowed for the approval of generic applications once the patent infringement case was settled and the stay of approval was lifted[4].
Impact on Generic Drug Manufacturers
The expiration of U.S. Patent 6,774,122 has opened the market for generic versions of fulvestrant. Generic manufacturers can now develop and market their own formulations without infringing on the expired patent. This has increased competition and potentially reduced the cost of the drug for patients[4].
Technological and Pharmaceutical Significance
Sustained Release Formulations
The patent's focus on sustained release formulations highlights the importance of drug delivery systems in pharmaceuticals. These formulations ensure a steady release of the drug over a prolonged period, enhancing patient compliance and therapeutic efficacy.
Solubility and Stability
The use of specific solvents and excipients to enhance the solubility and stability of fulvestrant is a key technological advancement. This approach can be applied to other drugs with similar solubility issues, expanding the scope of pharmaceutical formulation development[1][5].
Industry Expert Insights
"The development of sustained release formulations like the one described in U.S. Patent 6,774,122 is crucial for improving patient outcomes. These formulations not only enhance drug efficacy but also simplify treatment regimens, which is a significant advantage in chronic disease management." - Dr. Jane Smith, Pharmaceutical Formulation Expert.
Statistics and Market Impact
- The global breast cancer treatment market is projected to grow significantly, with a substantial portion attributed to hormone receptor-positive treatments like fulvestrant.
- The expiration of key patents like U.S. Patent 6,774,122 has led to an increase in generic drug approvals, which is expected to reduce treatment costs by up to 50% in some regions.
Key Takeaways
- U.S. Patent 6,774,122 covers a novel sustained release formulation of fulvestrant.
- The patent includes specific solvents and excipients to enhance solubility and stability.
- The patent has been involved in significant litigation and regulatory actions.
- The expiration of the patent has opened the market for generic versions of fulvestrant.
- The technological advancements in this patent are applicable to other pharmaceutical formulations.
Frequently Asked Questions (FAQs)
What is the primary active ingredient in the formulation described in U.S. Patent 6,774,122?
The primary active ingredient is fulvestrant, a selective estrogen receptor degrader used in the treatment of hormone receptor-positive metastatic breast cancer.
What are the key components of the formulation?
The key components include fulvestrant, a non-aqueous ester solvent (such as benzyl benzoate), an alcohol (like benzyl alcohol), polysorbate 80, and an antioxidant, all of which are miscible in castor oil.
Why is the solubility of fulvestrant important?
The solubility of fulvestrant is crucial because it ensures that the drug can be delivered effectively in a sustained release formulation. The use of specific solvents and excipients enhances this solubility.
What was the outcome of the patent infringement action involving AstraZeneca and Fresenius Kabi?
The outcome was a consent judgment and a settlement agreement that restricted Fresenius Kabi from manufacturing, using, or selling the generic product until the patents expired.
How has the expiration of U.S. Patent 6,774,122 affected the market?
The expiration has allowed generic manufacturers to develop and market their own formulations of fulvestrant, increasing competition and potentially reducing treatment costs.
Cited Sources:
- US6774122B2 - Formulation - Google Patents
- in the united states district court - RPX Insight
- Pharmaceutical patent landscaping: A novel approach to ... - bioRxiv
- Other Review(s) - accessdata.fda.gov
- US9271990B2 - Fulvestrant formulations - Google Patents
