United States Patent 6,811,794: A Detailed Analysis of Scope and Claims
Introduction
The United States Patent 6,811,794, along with its companion patents 5,854,290 and 6,287,599, is a crucial part of the intellectual property portfolio related to the drug Intuniv®, which is used to treat Attention Deficit Hyperactivity Disorder (ADHD) and other behavioral disorders. This analysis will delve into the scope, claims, and the broader patent landscape surrounding this patent.
Background of the Patent
The patent 6,811,794 is held by Shire LLC and Supernus Pharmaceuticals, Inc., and it pertains to the manufacture and sale of guanfacine hydrochloride extended-release tablets. Guanfacine is a medication known for its efficacy in treating ADHD and other behavioral disorders with minimal sedative side effects[1][2][4].
Scope of the Patent
The scope of the patent is defined by its claims, which outline the specific inventions and innovations covered. Here, the patent claims methods and compositions related to the extended-release formulation of guanfacine hydrochloride.
Claim Construction
Claim construction is a critical aspect of patent law, as it determines the scope of protection afforded to the patentee. The court's interpretation of claim language is guided by several principles:
- The specification of the patent is highly relevant and often dispositive in claim construction analysis[1].
- The claims should be interpreted according to their ordinary and accustomed meaning, unless the patent inventor clearly supplies a different meaning[1].
- Extrinsic evidence, such as expert testimony and dictionaries, can be considered but is less reliable than the patent and its prosecution history[1].
Specific Claims
The '794 patent specifically claims the use of guanfacine hydrochloride in an extended-release tablet formulation. It focuses on the rate of release of the active ingredient from the tablet, which is a key aspect of the extended-release mechanism[1][2].
Patent Landscape
The patent landscape surrounding 6,811,794 is complex and involves multiple stakeholders.
Companion Patents
The '794 patent is part of a family of patents that include 5,854,290 and 6,287,599. These patents collectively cover various aspects of guanfacine hydrochloride, including its use in treating behavioral disorders and the specific formulations used in Intuniv®[1][2][5].
Litigation and Infringement
The patent has been involved in several litigation cases, particularly under the Hatch-Waxman Act, which governs patent infringement actions related to pharmaceuticals. For instance, Shire LLC has sued several generic drug manufacturers, including Impax Laboratories and Sandoz Inc., for submitting Abbreviated New Drug Applications (ANDAs) that allegedly infringe on these patents[2][4][5].
Discovery and Interrogatories
In these litigation cases, the courts have had to address various discovery motions and interrogatories related to the infringement contentions. Shire has provided detailed infringement contentions, including charts that identify where each limitation of each asserted claim is found within the accused generic formulations[4].
Infringement Theories
Shire's infringement theories are based on several key points:
- Literal Infringement: Shire argues that the generic formulations meet the claim limitations literally.
- Doctrine of Equivalents: Alternatively, Shire contends that the generic formulations infringe under the doctrine of equivalents, using measurements such as percent dissolved over time, incremental percent increase, and percent of previous increase[4].
Judicial Interpretations
The courts have played a significant role in interpreting the claims of the '794 patent. For example, in the case of Shire LLC v. Impax Labs, Inc., the court found Shire's responses to the infringement contention interrogatories sufficient, relying on the detailed analysis provided by Shire[4].
Metrics for Measuring Patent Scope
The scope of a patent can be measured using various metrics, such as independent claim length and independent claim count. These metrics help in assessing the breadth and clarity of the patent claims, which are crucial in evaluating patent quality and potential litigation risks[3].
Impact on Innovation
The breadth and clarity of patent claims, such as those in the '794 patent, can significantly impact innovation in the pharmaceutical industry. Overly broad or unclear claims can lead to increased licensing and litigation costs, potentially diminishing incentives for innovation[3].
Key Takeaways
- Patent Scope: The '794 patent covers specific methods and compositions related to guanfacine hydrochloride extended-release tablets.
- Claim Construction: The interpretation of claim language is guided by the patent specification and ordinary meaning of the words.
- Litigation: The patent has been involved in several infringement cases under the Hatch-Waxman Act.
- Infringement Theories: Shire's infringement theories include literal infringement and infringement under the doctrine of equivalents.
- Judicial Interpretations: Courts have interpreted the claims to determine infringement, relying on detailed analyses provided by the parties.
FAQs
What is the main subject of United States Patent 6,811,794?
The main subject of the patent is the manufacture and sale of guanfacine hydrochloride extended-release tablets used to treat ADHD and other behavioral disorders.
Who are the holders of the patent?
The patent is held by Shire LLC and Supernus Pharmaceuticals, Inc.
What are the key claims of the patent?
The key claims relate to the extended-release formulation of guanfacine hydrochloride and the rate of release of the active ingredient from the tablet.
What is the significance of claim construction in patent law?
Claim construction determines the scope of protection afforded to the patentee and is guided by principles such as the specification's relevance and the ordinary meaning of the claim language.
How has the patent been involved in litigation?
The patent has been involved in several infringement cases under the Hatch-Waxman Act, with Shire LLC suing generic drug manufacturers for alleged infringement.
Sources
- District of Delaware: "Use of guanfacine in the treatment of behavioral disorders" - March 2012.
- United States District Court for the Northern District of California: "Shire LLC v. Impax Laboratories, Inc." - November 2012.
- Hoover Institution: "Patent Claims and Patent Scope" - August 2016.
- Casetext: "Shire LLC v. Impax Labs., Inc."
- Casetext: "Shire LLC v. Sandoz Inc."
