Colorectal cancer is the second commonest cancer worldwide and the third leading cause of cancer deaths. It commonly arises as an adenocarcinoma from a previous polyp. The treatment of such cancer depends mainly on the stage. Total surgical excision remains the only curative measure. In advanced cases, surgery with chemotherapy/ radiation or chemotherapy/ radiation are attempted. This paper focuses on the advancement in biological therapy and its contribution to the treatment of metastatic colon cancer. The types of biological therapy used this paper will detail are the non- specific immune stimulants (levamisole, IFN), monoclonal antibodies (edrocolomab, bevacizumab, panitumumab, cetuximab and vaccines.