United States Patent 6,936,612: A Detailed Analysis of Scope, Claims, and Patent Landscape
Introduction
The United States Patent 6,936,612, titled "2-(Pyridin-2-ylamino)-pyrido[2,3-d]pyrimidin-7-ones," is a significant patent in the pharmaceutical industry, particularly in the context of cancer treatment. This patent is held by Pfizer Inc. and is associated with the drug Palbociclib, marketed under the brand name IBRANCE®.
Background
Palbociclib is a selective inhibitor of cyclin-dependent kinases 4 and 6 (CDK4/6), which are crucial for cell cycle progression. The drug is used in the treatment of certain types of breast cancer, specifically HR-positive, HER2-negative advanced or metastatic breast cancer.
Scope of the Patent
The patent 6,936,612 covers a specific class of compounds known as 2-(pyridin-2-ylamino)-pyrido[2,3-d]pyrimidin-7-ones. These compounds are characterized by their unique chemical structure and their therapeutic efficacy as CDK4/6 inhibitors.
Chemical Structure
The patent describes the chemical structure of the compounds in detail, including the specific moieties and their arrangements. For instance, Claim 1 of the patent specifies a compound that is "6-Acetyl-8-cyclopentyl-5-methyl-2-(5-piperazin-1-yl-pyridin-2-ylamino)-8H-pyrido[2,3-d]pyrimidin-7-one," which is the active ingredient in Palbociclib[2].
Claims of the Patent
The patent includes several claims that define the scope of the invention.
Claim 1: Compound Claim
Claim 1 describes the specific chemical compound that is the core of the invention. This claim is critical as it defines the exact structure of the compound that is protected by the patent[2].
Claim 2: Pharmaceutical Composition Claim
Claim 2 covers a pharmaceutical composition that includes a therapeutically effective amount of the compound described in Claim 1, along with a pharmaceutical carrier. This claim ensures that the patent protection extends to the final drug product, not just the active ingredient[2].
Patent Landscape
The patent landscape surrounding 6,936,612 is complex and involves several related patents and legal proceedings.
Related Patents
The patent 6,936,612 is part of a family of patents that cover various aspects of Palbociclib, including its synthesis, formulations, and uses. Other patents in this family include U.S. Patent Nos. 7,208,489 and 7,456,168, which also relate to the compound and its pharmaceutical compositions[2][4].
Patent Litigation
Pfizer Inc. has been involved in several patent litigation cases to protect its intellectual property rights related to Palbociclib. For example, Pfizer sued Zydus Worldwide DMCC for submitting an Abbreviated New Drug Application (ANDA) to the FDA, seeking approval to manufacture and sell generic versions of Palbociclib before the expiration of the patents-in-suit[2].
Hatch-Waxman Act
The litigation involving Zydus is a classic example of the process outlined under the Hatch-Waxman Act, which allows generic drug manufacturers to challenge branded pharmaceutical companies' patents. This process involves the submission of an ANDA with a Paragraph IV certification, which alleges that the branded company's patents are invalid or not infringed by the generic product[2].
International Classification
The patent 6,936,612 falls under the International Patent Classification (IPC) code C07D, which includes heterocyclic compounds. This classification is consistent with the broader trend in pharmaceutical patenting, where a significant portion of patents are related to heterocyclic compounds due to their pharmacological relevance[3].
Patent Term Extension
Pfizer has also sought patent term extensions for U.S. Patent Nos. 6,936,612 and 7,208,489 under 35 U.S.C. § 156, which allows for the extension of the patent term to compensate for delays in the FDA approval process[5].
Impact on the Pharmaceutical Industry
The patent 6,936,612 has a significant impact on the pharmaceutical industry, particularly in the area of cancer treatment. By protecting the intellectual property related to Palbociclib, Pfizer has been able to maintain market exclusivity and continue to invest in research and development of new cancer therapies.
Market Exclusivity
The patent protection ensures that Pfizer can maintain market exclusivity for Palbociclib, preventing generic versions from entering the market until the patents expire. This exclusivity is crucial for Pfizer to recoup its investment in the development of the drug.
Research and Development
The revenue generated from Palbociclib sales enables Pfizer to continue investing in research and development, including the exploration of new indications for the drug and the development of other CDK4/6 inhibitors.
Key Takeaways
- Chemical Structure: The patent covers a specific class of compounds known as 2-(pyridin-2-ylamino)-pyrido[2,3-d]pyrimidin-7-ones.
- Claims: The patent includes claims for the compound and pharmaceutical compositions.
- Patent Landscape: The patent is part of a family of patents related to Palbociclib and has been involved in patent litigation.
- International Classification: The patent falls under IPC code C07D.
- Impact: The patent has significant implications for market exclusivity and research and development in the pharmaceutical industry.
FAQs
What is the main compound protected by U.S. Patent 6,936,612?
The main compound protected is "6-Acetyl-8-cyclopentyl-5-methyl-2-(5-piperazin-1-yl-pyridin-2-ylamino)-8H-pyrido[2,3-d]pyrimidin-7-one," which is the active ingredient in Palbociclib.
What are the key claims of the patent?
The key claims include Claim 1, which describes the specific chemical compound, and Claim 2, which covers pharmaceutical compositions containing the compound.
Why is this patent important for Pfizer?
This patent is crucial for Pfizer as it protects the intellectual property related to Palbociclib, allowing the company to maintain market exclusivity and continue investing in research and development.
What is the Hatch-Waxman Act, and how does it relate to this patent?
The Hatch-Waxman Act allows generic drug manufacturers to challenge branded pharmaceutical companies' patents. Pfizer has been involved in litigation under this act to protect its patents related to Palbociclib.
How does the patent classification affect the broader pharmaceutical industry?
The classification under IPC code C07D reflects the broader trend in pharmaceutical patenting, where heterocyclic compounds are frequently patented due to their pharmacological relevance.
Cited Sources
- United States Patent and Trademark Office, "Reissued Patent: US RE47,739 E," November 26, 2019.
- United States District Court for the District of Delaware, "Pfizer Inc. v. Zydus Worldwide DMCC," April 25, 2019.
- bioRxiv, "Pharmaceutical patent landscaping: A novel approach to understanding the scope of patenting activity within disease areas," March 23, 2023.
- United States Patent and Trademark Office, "United States Patent: US 10,723,730 B2," July 28, 2020.
- Regulations.gov, "Patent Term Extension Applications for U.S. Patent Nos. 6,936,612 and 7,208,489," FDA-2016-E-1184-0006.
