Compositions and methods for treatment of cancer using bacteria
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Publication Number
US-9265804-B2
Publication Date
2016-02-23
Expiration Date
Abstract
Provided herein are compositions comprising substantially non-viable Gram-negative bacterial organisms that have a substantial reduction in endotoxin activity and/or pyrogenicity and methods for treating a cancer using the same. Also provided are methods for treating cancer provided herein, comprising administering to a mammal diagnosed with cancer, substantially non-viable Gram-negative bacteria having a substantial reduction in endotoxin activity and/or pyrogenicity, in an amount sufficient to inhibit growth or metastasis of the cancer. An additional method is provided comprising administering viable or non-viable Gram-negative bacterial organisms that have a genetic defect that results in a substantial loss of lipopolysaccharide within the outer membrane of the bacteria. Further provided are methods for reducing endotoxin activity and/or pyrogenicity in Gram-negative bacteria comprising treatment with polymyxin and glutaraldehyde.
Core Innovation
The disclosure relates to treating cancer by administering compositions that comprise intact and substantially non-viable Gram-negative bacterial cells with substantially reduced endotoxin activity and pyrogenicity. The compositions are formulated with pharmaceutically acceptable excipients/carriers, while the bacterial cells are treated so that endotoxin activity and pyrogenicity are substantially reduced without loss of cell integrity. The described approach targets the endotoxin basis of Gram-negative bacteria to support cancer treatment outcomes.
A problem addressed in the background is that Gram-negative bacterial cells inherently include endotoxin activity and pyrogenicity, which can limit their use when cells are administered to a mammal or a cancer patient. The disclosure therefore addresses the need to reduce endotoxin activity and pyrogenicity while preserving intact bacterial cell integrity. The document further provides definitions and measurement approaches for endotoxin and pyrogenicity to evaluate the reduction achieved.
The disclosure describes treating Gram-negative bacterial cells with polymyxin B and polymyxin E under conditions to reduce viability, endotoxin activity, and pyrogenicity without loss of intact cell integrity. It also describes alternative and combination strategies for reducing endotoxin and pyrogenicity, including glutaraldehyde treatment and combinations of polymyxin B plus glutaraldehyde. In addition, the disclosure describes Gram-negative bacterial cells having genetic defects that reduce or prevent LPS, including KDO2-Lipid IV A biosynthesis defects and preventing O-acylation of KDO2-Lipid IV A, as well as msbB/lpxM related defects.
The document includes mechanistic rationale that the reduction in lipid A-mediated toxicity is associated with the reduced endotoxin activity and pyrogenicity of the treated cells. Experimental confirmation described in the disclosure includes assessments such as TEM confirmation of intact cells and measurement approaches using LAL, including a kinetic assay, and rabbit pyrogen tests. The disclosure further outlines in vivo tumor growth inhibition in murine melanoma and colorectal cancer model contexts, including combination contexts with cyclophosphamide and immune checkpoint blockade (anti-CTLA-4).
Claims Coverage
The partial content includes three independent claims, each addressing a different core implementation for treating cancer with substantially non-viable intact Gram-negative bacterial cells while reducing endotoxin activity and pyrogenicity and enabling a decrease in growth or metastasis. The inventive features are grounded in polymyxin B treatment to preserve cell integrity, genetic defects affecting KDO2-Lipid IV A biosynthesis or O-acylation, and a method framing that includes preparing a plurality of polymyxin B-treated intact non-viable cells and administering them to a cancer patient.
Polymyxin B-treated intact substantially non-viable Gram-negative bacterial cells for cancer treatment
Administering to a mammal with cancer a composition that comprises an amount of intact and substantially non-viable Gram-negative bacterial cells, wherein the bacterial cells are treated with polymyxin B under conditions to reduce viability, endotoxin activity and pyrogenicity of the cells without loss of cell integrity such that the cells have a substantial reduction in endotoxin activity and pyrogenicity as compared to untreated bacterial cells, and wherein the amount administered is sufficient to decrease growth or metastasis of the cancer.
KDO2-Lipid IVA pathway genetic defect in intact substantially non-viable Gram-negative bacterial cells
Administering to a mammal with cancer a composition that comprises an amount of intact and substantially non-viable Gram-negative bacterial cells, wherein the bacterial cells comprise a genetic defect that disrupts the biosynthesis of KDO2-Lipid IV A or a genetic mutation that prevents O-acylation of KDO2-Lipid IV A sufficient to substantially reduce endotoxin activity and pyrogenicity and wherein the amount administered is sufficient to decrease growth or metastasis of the cancer.
Polymyxin B treatment to obtain a plurality of intact substantially non-viable cells and administer to a cancer patient
Treating Gram-negative bacterial cells with polymyxin B under conditions to reduce viability, endotoxin activity and pyrogenicity of the cells without loss of cell integrity, to obtain a plurality of intact and substantially non-viable Gram-negative bacterial cells with substantial reduction in endotoxin activity and pyrogenicity as compared to untreated bacterial cells, and administering the plurality of intact and substantially non-viable Gram-negative bacterial cells to a cancer patient.
Across the independent claims, the coverage centers on cancer treatment using intact and substantially non-viable Gram-negative bacterial cells that have substantially reduced endotoxin activity and pyrogenicity. The claim strategies differ by polymyxin B treatment while preserving cell integrity, genetic defects affecting KDO2-Lipid IV A biosynthesis or O-acylation to reduce endotoxin activity and pyrogenicity, and a method flow that prepares polymyxin B-treated intact non-viable cells and administers a plurality of them to a cancer patient.
Stated Advantages
A substantial reduction in endotoxin activity and pyrogenicity as compared to untreated bacterial cells while maintaining cell integrity.
An administered amount sufficient to decrease growth or metastasis of the cancer.
Documented Applications
Treating a cancer by administering compositions comprising intact and substantially non-viable Gram-negative bacterial cells with substantially reduced endotoxin activity and pyrogenicity to a mammal or cancer patient.
In vivo tumor growth inhibition in murine melanoma (B16F10) and colorectal cancer (CT26) model contexts is described.
Combination contexts are described, including use with cyclophosphamide and with immune checkpoint blockade (anti-CTLA-4).
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