United States Patent 5,412,095: A Detailed Analysis of Scope and Claims
Introduction
United States Patent 5,412,095, hereafter referred to as the '095 patent, is a significant patent in the pharmaceutical industry, particularly related to the drug terazosin hydrochloride. This patent was filed on May 20, 1994, and issued on May 2, 1995. Here, we will delve into the scope, claims, and the broader patent landscape surrounding this invention.
Background of the Patent
The '095 patent protects a crystalline polymorph of terazosin hydrochloride, specifically identified as "Form III" based on its x-ray diffraction pattern. Terazosin hydrochloride is a medication used primarily for treating hypertension and benign prostatic hyperplasia (BPH)[1].
Patent Claims
The '095 patent includes several claims that define the scope of the invention. Here are the key aspects:
Independent Claims
The patent claims a crystalline polymorph of terazosin hydrochloride characterized by a specific x-ray diffraction pattern. This polymorph, known as "Form III," is distinct from other forms of terazosin hydrochloride, such as "Form II" and "Form IV," which are protected under different patents[1].
Dependent Claims
Dependent claims further specify the methods of preparing this crystalline polymorph and its use in pharmaceutical compositions. These claims ensure that any process or product that utilizes this specific form of terazosin hydrochloride falls within the scope of the patent[1].
Patent Scope and Exclusivity
The '095 patent is listed in the "Orange Book," a publication by the FDA that lists approved drugs and their associated patents. This listing is crucial because it informs generic drug manufacturers about the patents that must be considered when seeking FDA approval for generic versions of brand-name drugs[1].
Exclusivity Period
The '095 patent was scheduled to expire on April 29, 2013, which marked the end of its exclusivity period. During this time, the patent holder had exclusive rights to manufacture, use, and sell the crystalline polymorph of terazosin hydrochloride as described in the patent[1].
Relationship with Other Patents
The '095 patent is part of a family of patents related to terazosin hydrochloride. Other patents, such as the '097 patent and the '207 patent, protect different polymorphs (Form II and Form IV) and methods of preparation. These patents collectively form a complex patent landscape around this drug[1].
Patent '097
The '097 patent, a divisional application of an earlier patent, protected a pharmaceutical composition of terazosin hydrochloride for treating hypertension and a method for treating hypertension with the drug. This patent expired earlier, on October 14, 1995[1].
Patent '207
The '207 patent, issued on April 2, 1996, protected a crystalline polymorph of terazosin hydrochloride known as "Form IV" and a process for preparing terazosin hydrochloride dihydrate using Form IV. This patent also had a significant impact on the generic drug market for terazosin hydrochloride[1].
Challenges and Litigation
The '095 patent, like other patents in the pharmaceutical sector, faced challenges from generic drug manufacturers. For instance, Geneva Pharmaceuticals filed Paragraph IV certifications with respect to the '095 patent, asserting that the patent was invalid under 35 U.S.C. ยง 102(b) due to prior sale or publication of the invention. However, these challenges were part of the broader strategy to enter the market with generic versions of terazosin hydrochloride[1].
Impact on Generic Drug Approval
Under the Hatch-Waxman Act, generic drug manufacturers must navigate the patent landscape carefully. The '095 patent, being listed in the Orange Book, required generic manufacturers to file Paragraph IV certifications or wait until the patent expired to avoid infringement claims. This process delays the entry of generic drugs into the market, allowing the brand-name drug to maintain market exclusivity for a longer period[1].
Conclusion on Patent Scope and Claims
The '095 patent is a critical component in the patent landscape surrounding terazosin hydrochloride. Its claims define a specific crystalline polymorph and its use, providing exclusivity to the patent holder until its expiration. Understanding the scope and claims of this patent is essential for both brand-name and generic drug manufacturers navigating the complex regulatory environment.
Key Takeaways
- Patent Scope: The '095 patent protects a crystalline polymorph of terazosin hydrochloride known as "Form III."
- Exclusivity: The patent was listed in the Orange Book and had an exclusivity period until April 29, 2013.
- Relationship with Other Patents: Part of a family of patents related to terazosin hydrochloride, including patents '097 and '207.
- Challenges and Litigation: Faced challenges from generic drug manufacturers, including Paragraph IV certifications.
- Impact on Generic Drug Approval: Required generic manufacturers to navigate the patent landscape carefully under the Hatch-Waxman Act.
FAQs
What is the '095 patent?
The '095 patent protects a crystalline polymorph of terazosin hydrochloride known as "Form III," characterized by a specific x-ray diffraction pattern.
When was the '095 patent issued?
The '095 patent was issued on May 2, 1995.
What is the significance of the Orange Book listing?
The Orange Book listing informs generic drug manufacturers about the patents that must be considered when seeking FDA approval for generic versions of brand-name drugs.
How did the '095 patent affect generic drug manufacturers?
Generic drug manufacturers had to file Paragraph IV certifications or wait until the patent expired to avoid infringement claims, delaying their entry into the market.
What other patents are related to terazosin hydrochloride?
Other related patents include the '097 patent and the '207 patent, which protect different polymorphs (Form II and Form IV) and methods of preparation.
Sources
- Kaiser v. Abbott Laboratories, Kaiser Foundation v. Abbott Laboratories, PDF.
- Steven E. Berkheimer V. HP Inc., Federal Circuit Court of Appeals, PDF.
- Patent Claims Research Dataset, USPTO.
- Search for Patents, USPTO.
- U.S. Patent Small Claims Court, Administrative Conference of the United States.
