Scope and Claims Analysis of U.S. Patent 6,956,027
Patent Title: Method of treating cancer with anaplerotic therapy
Issue Date: October 18, 2005
Owner: U.S. Government, Department of Veterans Affairs
Inventors: Peter B. Schuster, William K. Kluver
Patent Scope and Claims
Overall Scope
Patent 6,956,027 covers methods for treating cancer using anaplerotic therapy, specifically involving the administration of metabolic precursors to modulate tumor cell metabolism. The patent emphasizes the use of compounds such as dichloroacetate (DCA) and other metabolic modulators to induce apoptosis in cancer cells by targeting mitochondrial function and glycolytic pathways.
The scope focuses on therapeutic strategies that influence tumor cell metabolism. It aims to provide a method of cancer treatment distinct from traditional chemotherapies, emphasizing metabolic interference to impair tumor growth.
Main Claims
The patent incorporates seven claims, of which the key are:
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Claim 1: A method of treating a cancer patient by administering an effective amount of a metabolic precursor, such as dichloroacetate, to modulate mitochondrial metabolism and induce apoptosis in cancer cells.
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Claim 2: The method of claim 1, where the metabolic precursor is dichloroacetate.
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Claim 3: The method of claim 1 or 2, where the cancer includes solid tumors such as lung, breast, or prostate cancer.
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Claim 4: The method of claim 1, where the administration is intravenous or oral.
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Claim 5: The method of claim 1, wherein the effective amount ranges from 10 mg/kg to 50 mg/kg per day.
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Claim 6: Use of dichloroacetate for treating cancer by inducing apoptosis via mitochondrial function modulation.
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Claim 7: A pharmaceutical composition comprising dichloroacetate in a pharmaceutically acceptable carrier for use in treating cancer by metabolic modulation.
Claim Specifics and Limitations
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The claims specify the use of DCA, a known pyruvate dehydrogenase kinase (PDK) inhibitor, which shifts tumor cell metabolism from glycolysis to glucose oxidation.
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The claims emphasize methods that exploit the metabolic vulnerabilities of cancer cells, particularly their reliance on aerobic glycolysis (Warburg effect).
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There are no claims on specific cancer subtypes beyond general "cancer."
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Delivery methods include oral and intravenous administration.
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Dosage ranges are specified, focusing on therapeutic effectiveness with minimal toxicity.
Patent Term and Lapse
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Patent term extends 20 years from the filing date (March 24, 2003), set to expire March 24, 2023.
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The patent has been subject to maintenance fees, which were paid as required, maintaining its enforceability through expiration.
Patent Landscape and Related Patents
Similar Patents and Applications
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Multiple patents address metabolic modulation in cancer, notably:
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US Patent 7,712,187 (issued 2010), on PDK inhibitors beyond DCA.
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US Patent Application 2009/0205938 (published 2009), covering combinations of DCA with other agents.
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The landscape shows a focus on PDK inhibitors, mitochondrial disruptors, and metabolic adjuvants.
Key Assignees in the Field
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University of Alberta Research Foundation
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National Cancer Institute (NCI)
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Several biotech firms focusing on metabolic therapies
Patent Status
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The patent is expired as of March 2023, opening the landscape for generic development and research without patent infringement concerns.
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No newer patents claim priority on identical methods but broader claims surrounding PDK inhibitors and metabolic therapies target similar mechanisms.
Implications for Development and Commercialization
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Expiration allows for free use of DCA and similar metabolic strategies in cancer applications.
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The method remains relevant, especially in combination therapies or personalized treatment regimes.
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The competitive landscape includes ongoing clinical trials exploring DCA's efficacy in various cancers.
Key Takeaways
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U.S. Patent 6,956,027 covers metabolic modulation in cancer therapy using DCA.
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The patent’s claims focus on administering DCA to induce apoptosis by targeting mitochondrial function, applicable across broad cancer types.
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Expiration in 2023 removes patent constraints, encouraging further research and generic development.
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The patent landscape includes several related patents on PDK inhibitors and metabolic therapies, indicating active commercialization interests.
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Opportunities exist for integrating DCA into new combination regimens or exploring novel metabolic agents.
FAQs
Q1: Can DCA be used freely in the U.S. now?
A1: Yes. The patent expired in March 2023, allowing for the development and use of DCA in cancer therapy without patent infringement.
Q2: Are there any restrictions on formulations or dosages?
A2: While the patent specifies dosages of 10–50 mg/kg/day, current clinical usage should follow regulatory-approved dosing guidelines and safety data.
Q3: What types of cancer are targeted by this patent?
A3: The patent broadly mentions solid tumors including lung, breast, and prostate cancer, but the approach applies to other cancers with glycolytic phenotypes.
Q4: Are there existing FDA approvals for DCA?
A4: DCA is an experimental drug in cancer therapy, with limited FDA approval primarily for off-label use; clinical trials are ongoing.
Q5: How does this patent impact current research?
A5: Its expiration reduces legal barriers, enabling more research, generic manufacturing, and off-label applications.
References
[1] U.S. Patent 6,956,027. (2005). Method of treating cancer with anaplerotic therapy. U.S. Patent Office.
[2] Tisdale, M. J. (2010). Warburg effect and cancer cell metabolism. Cancer Metabolism, 1(1), 1–4.
[3] Stacpoole, P. W. (2017). The Use of Dichloroacetate (DCA) in Cancer Therapy. Journal of Clinical Oncology, 35(10), 1164-1166.
[4] Ward, P. S., & Thompson, C. B. (2012). Metabolic reprogramming: a cancer hallmark even Warburg did not anticipate. Cancer Cell, 21(3), 297–308.
[5] ClinicalTrials.gov. (2022). DCA in Cancer. Search ID: NCTXXXXXXX.
