United States Patent 5,952,323: A Detailed Analysis of Scope, Claims, and Patent Landscape
Introduction
The United States Patent 5,952,323, owned by Merck Sharp & Dohme Corp., is a pivotal patent in the pharmaceutical industry, particularly in the realm of antibiotic development. This patent pertains to a carbapenem antibiotic composition, specifically the stabilized form of ertapenem, and the methods of its preparation.
Background of the Patent
Ertapenem, a carbapenem antibiotic, is highly unstable and requires specific formulations to maintain its efficacy. The '323 patent addresses this issue by describing a stable composition of ertapenem and the methods for its stabilization[4][5].
Scope of the Patent
Stable Composition of Ertapenem
The patent describes a stabilized form of ertapenem, which is crucial for its pharmaceutical use. This stability is achieved through the formation of a carbamate adduct, specifically the carbon dioxide adduct of ertapenem. This adduct helps in minimizing the degradation pathways such as dimerization and hydrolysis, ensuring the antibiotic remains effective[4][5].
Methods of Preparation
The patent outlines detailed methods for preparing the stabilized ertapenem composition. These methods include the use of various diluents, buffers, preservatives, and tonicity controlling agents to ensure the formulation is suitable for injection. The patent specifies that the composition can include sterile water for injection, normal saline, and other diluents, along with buffers like phosphate and citrate buffers[4].
Claims of the Patent
The '323 patent includes several claims that define the scope of the invention:
- Claim 1: A stabilized carbapenem antibiotic composition, specifically the carbon dioxide adduct of ertapenem.
- Claims 2-6: Various embodiments of the composition, including different diluents, buffers, preservatives, and tonicity modifying agents[4].
Validity and Infringement
Litigation Overview
The validity and infringement of the '323 patent have been subjects of litigation, particularly in the cases involving generic manufacturers seeking to market their own versions of ertapenem. In Merck Sharp & Dohme Corp. v. Hospira Inc., the court found the asserted claims of the '323 patent to be valid and infringed by Hospira's generic product[5].
Challenges to Validity
Despite its validity being upheld in several cases, the '323 patent has faced challenges. For instance, in the same litigation, the court determined that the '150 patent, which describes a process for preparing the carbamate adduct of ertapenem, was invalid for obviousness. However, this did not affect the validity of the '323 patent, as it was deemed to describe a novel and non-obvious composition[5].
Patent Landscape
Related Patents
The '323 patent is part of a broader patent landscape related to ertapenem. Other patents, such as the '150 patent, describe processes for preparing the stabilized form of ertapenem. These patents collectively protect Merck's intellectual property related to the development and manufacture of ertapenem[2][5].
Generic Challenges
Generic manufacturers have filed Abbreviated New Drug Applications (ANDAs) seeking FDA approval to market generic versions of Invanz®, Merck's product containing ertapenem. These filings have led to several patent infringement lawsuits, with the '323 patent being a central issue in these cases[2][5].
Impact on the Pharmaceutical Industry
The '323 patent has significant implications for the pharmaceutical industry, particularly in the development of antibiotics. The stabilized form of ertapenem described in the patent ensures the antibiotic's efficacy and stability, which is crucial for patient treatment.
Innovation and Competition
The patent encourages innovation by protecting Merck's investment in research and development. However, it also limits competition from generic manufacturers, which can delay the availability of more affordable generic versions of the drug[5].
Expert Insights
Industry experts emphasize the importance of such patents in driving pharmaceutical innovation. For example, Dr. Miles A. Finn, counsel in the Merck Sharp & Dohme Corp. v. Hospira Inc. case, highlighted the significance of patent protection in ensuring that companies continue to invest in the development of new and improved medications[5].
Statistics and Trends
The protection afforded by the '323 patent is part of a larger trend in pharmaceutical patenting. According to the USPTO's Patent Claims Research Dataset, patents related to pharmaceutical compositions and methods of preparation are among the most frequently filed and litigated patents[3].
Conclusion
The United States Patent 5,952,323 is a critical component of Merck's intellectual property portfolio related to ertapenem. The patent's scope, claims, and the surrounding patent landscape highlight its importance in the pharmaceutical industry. It ensures the stability and efficacy of ertapenem, a vital antibiotic, while also influencing the balance between innovation and competition.
Key Takeaways
- The '323 patent describes a stable composition of ertapenem and its methods of preparation.
- The patent has been upheld as valid and infringed in several litigation cases.
- It is part of a broader patent landscape related to ertapenem, including the '150 patent.
- The patent has significant implications for the pharmaceutical industry, balancing innovation and competition.
- Generic manufacturers continue to challenge the patent as part of their efforts to market generic versions of Invanz®.
Frequently Asked Questions
What is the main subject of the '323 patent?
The '323 patent pertains to a stable composition of the antibiotic ertapenem and the methods for its stabilization.
Why is the stability of ertapenem important?
The stability of ertapenem is crucial because the antibiotic is highly unstable and prone to degradation through dimerization and hydrolysis.
What are the key claims of the '323 patent?
The key claims include the stabilized carbapenem antibiotic composition and various embodiments of the composition, including different diluents, buffers, and preservatives.
Has the '323 patent been challenged in court?
Yes, the '323 patent has been challenged in court, particularly in cases involving generic manufacturers. However, its validity has been upheld in several instances.
How does the '323 patent impact the pharmaceutical industry?
The patent encourages innovation by protecting Merck's investment in research and development but also limits competition from generic manufacturers, affecting the availability of affordable generic versions of the drug.
Cited Sources:
- Merck Sharp & Dohme Corp. v. Hospira, Inc., No. 17-1115 (Fed. Cir. Oct. 26, 2017)
- Merck Sharp & Dohme Corp. v. Savior Lifetec Corp.
- Patent Claims Research Dataset - USPTO
- US5952323A - Carbapenem antibiotic - Google Patents
- Merck Sharp & Dohme Corp. v. Hospira Inc. | Resources | Robins Kaplan
