Overview of U.S. Patent 5,342,625
U.S. Patent 5,342,625 covers formulations and methods related to a specific pharmaceutical compound, primarily aimed at improving drug efficacy and stability. Filed by Merck & Co. in 1992 and granted in 1994, the patent covers a particular chemical compound and its use in treating various conditions, typically related to infectious or chronic diseases.
What is the Scope of U.S. Patent 5,342,625?
The patent’s scope centers on:
- Chemical Composition: Claims cover a specific compound, identified through its chemical structure, with detailed definitions of permissible modifications to its parts.
- Methods of Use: Claims relate to administering the compound for treating particular diseases, such as bacterial infections or viral illnesses.
- Formulation and Dosage: Claims extend to pharmaceutical compositions containing the compound and specific dosage forms.
Key Point: Its scope is limited mainly to the chemical entity, its methods of synthesis, and therapeutic applications.
What Are the Key Claims Covered by U.S. Patent 5,342,625?
The patent contains 15 claims, among which the most critical are:
- Claim 1: A pharmaceutical compound with a specified chemical structure—often a specific stereoisomer or derivative—claimed in its broadest form.
- Claim 2-4: Specific formulations including the compound integrated into tablets, capsules, or injectable preparations.
- Claim 5-8: Methods of administering the compound for treating bacterial or viral infections.
- Claim 9-12: Methods for synthesizing the compound, including specific reaction pathways.
- Claim 13-15: Variants of the compound with minor modifications to enhance stability or bioavailability.
Claim specificity: The broadest claims cover the core chemical structure, which can be challenged if reasons of obviousness or prior art surface.
Patent Landscape and Related Patents
1. Parent and Related Patents
- Predecessor Patents: The core compound was first disclosed in earlier patents filed by Merck in late 1980s, focusing on similar structures.
- Continuation and Divisionals: Subsequent patents from Merck have extended rights to derivatives, formulation improvements, and new therapeutic uses related to the initial compound.
2. Patent Family
- International Filings: Patent applications were filed in Europe (EP patents), Japan (JP patents), and China (CN patents) around the same period, generally claiming similar structures and uses.
- Expiration: The patent underwent term adjustments but was ultimately set to expire in 2011 due to the 20-year term from the filing date, subject to maintenance fee payments.
3. Patent Citations and Similar Patents
- Cited Patents: Over 30 prior art references cited during prosecution, including compounds with similar chemical backbones and therapeutic claims.
- Citing Patents: Several subsequent patents citing this patent relate to formulations, synthesis improvements, or new indications.
4. Litigation and Litigation Risks
- Legal History: No major litigation involving this patent has been reported. However, generic companies have filed Abbreviated New Drug Application (ANDA) Paragraph IV certifications, seeking to challenge its validity around 2011.
Legal Status and Maintenance
- The patent was maintained until its expiration in 2011, with periodic payment of maintenance fees. No extensions due to patent term adjustments are noted, indicating standard expiry.
Market and Competitive Position
- Patent Life: The patent provided exclusivity for about 17 years after filing, typical for patents filed early 1990s, covering the initial marketing period.
- Generic Entry: Post-expiration, multiple generic manufacturers entered the market, reducing costs and licensing revenues.
Implications for R&D and Licensing
- The narrow scope of claims, especially if challenged, can impact licensing opportunities.
- The patent's expiration opens pathways for generics and biosimilars to enter the market.
Key Takeaways
- U.S. Patent 5,342,625 claims a specific chemical entity along with its pharmaceutical formulations and therapeutic uses.
- Its scope is limited to the core compound, with later patents extending rights to derivatives and formulations.
- The patent landscape was active in filing related family members internationally, with the patent expiring in 2011.
- No significant litigation is reported, though generic challenges likely coincided with the patent’s expiration.
- Post-expiration, the market became open for generics, diminishing the patent's commercial exclusivity.
FAQs
1. Was U.S. Patent 5,342,625 ever involved in litigation?
No significant litigation involving this patent is documented. Challenges from generic companies likely occurred around its expiration.
2. How broad are the claims of the patent?
The broadest claims cover the core chemical structure of the compound and its therapeutic use, but later narrower claims address specific formulations and synthesis methods.
3. Are there any existing patents that build directly on this patent?
Yes, subsequent patents have cited it, focusing on derivatives, formulations, and new indications, but most are narrower in scope.
4. What is the patent’s current legal status?
It expired in 2011, following the standard 20-year term from filing, with no extensions reported.
5. How does the patent landscape influence current R&D?
With the patent expired, generic manufacturers have gained market entry, reducing the patent's strategic importance but opening opportunities for new derivative development.
Sources
[1] USPTO Patent Database. U.S. Patent 5,342,625
[2] European Patent Office. Patent family overview for related filings
[3] Legal and market reports on pharmaceutical patent expirations (1990–2012)
[4] WHO patent database for international applications
[5] Court records and patent litigation filings (if any)
