 This is a Phase II, multi-center study of GM-CT-01 which has been shown to increase the anti-tumor activity of 5-fluorouracil 5-FU in mice. 5-FU is a chemotherapy drug commonly used in cancer patients. In this Phase II study, patients with colon cancer which has spread, despite treatment with approved therapies, will receive GM-CT-01 plus 5-FU in monthly cycles for at least 2 cycles or until their disease progresses. 