Tumor-targeted Salmonella typhimurium overexpressing cytosine deaminase: a novel, tumor-selective therapy.

The ideal anticancer regimen is one that is specific for cancer cells with limited toxicity to normal tissues. Genetically modified, nonpathogenic Salmonella offer a potential way to induce direct tumoricidal activity or to deliver tumoricidal agents to tumors. An attenuated strain of Salmonella typhimurium, called VNP20009, and its derivative TAPET-CD (which expresses Escherichia coli cytosine deaminase) are highly selective for tumor tissue and can deliver therapeutic proteins preferentially to tumors in preclinical models. Both VNP20009 and TAPET-CD have been investigated successfully in Phase 1 clinical trials in cancer patients.