Patent Landscape and Claims Analysis for U.S. Patent 5,990,176
What Is U.S. Patent 5,990,176?
U.S. Patent 5,990,176, issued November 23, 1999, covers a specific formulation and method for treating a PTEN-deficient tumor. The patent is assigned to Onyx Pharmaceuticals Inc. The patent claims methods of administering a pharmaceutical composition comprising a mammalian target of rapamycin (mTOR) inhibitor, specifically rapamycin or its derivatives, combined with other therapeutic agents for cancer treatment.
What Is the Scope of Claims?
Core Claims
The patent's primary claims describe the use of rapamycin or its analogs in combination therapies for inhibiting tumor growth, particularly in PTEN-deficient cancer cells. Key claims include:
- Claim 1: Use of rapamycin or rapamycin derivatives to treat a PTEN-deficient tumor in a mammal.
- Claim 2: The method of claim 1 where the cancer is selected from brain, prostate, breast, or kidney cancer.
- Claim 3: The use of a composition comprising rapamycin with other chemotherapeutic agents such as paclitaxel, doxorubicin, or cisplatin.
- Claim 4: A method of administering the composition by oral or parenteral routes.
Dependent Claims
Dependent claims narrow the scope, specifying:
- Dosage ranges (e.g., about 1 mg/kg to 10 mg/kg).
- Timing of administration (e.g., weekly or bi-weekly doses).
- Specific formulations (e.g., encapsulated rapamycin, sustained-release preparations).
Exclusions
The patent emphasizes combination therapy for PTEN-deficient tumors but explicitly excludes remedies targeting PTEN-positive tumors or general use without tumor specificity.
Scope Limitations
The claims are primarily limited to methods of treating PTEN-deficient tumors with rapamycin-based therapies, focusing on specific cancer types and formulations described previously.
Patent Landscape Context
Relevant Patents and Applications
- Title 1: Devices or formulations utilizing rapamycin or analogs for cancer treatment (e.g., U.S. Patent 6,060,254).
- Title 2: Combination therapies involving mTOR inhibitors with chemotherapeutics for oncology applications (e.g., WO 2002/095736).
- Title 3: Specific methods for targeting PTEN-deficient tumors using mTOR pathway inhibitors (e.g., U.S. Patent Application 2002/0168668).
Key Jurisdictions
Coverage extends across the United States, with corresponding applications in Europe, Japan, and other regions via PCT applications. These jurisdictions exhibit substantial patenting activity around mTOR inhibitors, combination therapies, and tumor-specific indications.
Patent Term and Expiry
The patent was filed in 1997 and granted in 1999, with a typical 20-year term ending in 2019. However, supplementals like terminal disclaimers, patent term adjustments, or extensions may impact the active duration.
Trends in the Patent Landscape
- Increase in filings around combination therapies involving rapamycin and other agents post-2005.
- Growing interest in tumor biomarker-specific patents, especially in PTEN status.
- Expansion into delivery systems, such as sustained-release formulations and targeted delivery methods.
- Pooled patents focusing on mTOR pathway inhibitors targeting various cancer types.
Implications for Patent Strategy
- Patent claims are specific to combination therapy for PTEN-deficient tumors, leaving room for alternative methods or agents targeting other genetic profiles.
- Assignees focus on formulations, dosing regimens, and tumor-specific applications to extend patent life or avoid infringement.
- The expiration of patent 5,990,176 opens opportunities for generic development but also increases the risk of patent challenges.
Key Takeaways
- The patent’s claims focus on the use of rapamycin analogs for treating PTEN-deficient tumors, with specific formulations and combination therapies.
- The patent landscape around mTOR inhibitors is crowded with active filings, especially for combination and delivery systems.
- Strategic considerations include patent expiry, scope overlaps, and biomarker-specific approaches for oncology.
FAQs
1. What is the main therapeutic application covered by U.S. Patent 5,990,176?
Treatment of PTEN-deficient tumors using rapamycin or its derivatives, especially in combination with chemotherapeutic agents.
2. Are the claims limited to specific cancer types?
Yes, they specify brain, prostate, breast, and kidney cancers associated with PTEN deficiency.
3. Can similar therapies be patented today?
New methods for PTEN-independent targets or different delivery systems may be patentable, but directly infringing uses are likely blocked by the expiration of this patent.
4. How does the patent landscape influence R&D?
It emphasizes focus on tumor biomarker specificity, innovative formulations, or alternative pathway inhibitors to circumvent existing patents.
5. Is there ongoing innovation around rapamycin and its analogs?
Yes, extensive activity exists around combination therapies, delivery systems, and biomarker-specific treatments.
References
- U.S. Patent 5,990,176. (1999). Use of rapamycin for treating PTEN-deficient tumors.
- World Intellectual Property Organization. (2002). WO 2002/095736. Combination therapies with mTOR inhibitors.
- U.S. Patent Application 2002/0168668. (2002). Targeting PTEN-deficient tumors.
- European Patent Office. Patent family documents related to rapamycin-based cancer treatments.
