GV1001 combination therapy in metastatic colorectal cancer

Interventions: Drug : Study design &Intervention schedule This study is a multicenter, phase 2, single arm study. Individual investigators are allowed to choose 2nd line chemotherapy agents,bevacizumab, cetuximab,aflibercept depending on their decision. GVl001 is injected intradermally on days 1, 3, 5 and 8 of the first cycle of 2nd line chemotherapy with a dose of 0.56 mg, and then injected on day 1 of subsequent chemotherapy. GV1001 should be injected intradermally in the lower abdomen with 0.2 mL of diluted to 0.30 mL of 0.9% normal saline (2.8 mg/mL), administered immediately after dilution (at least within 6 hours after dilution). This treatment is repeated every 2 weeks until the discontinuation of treatment due to the patients’ request, the toxicity, or the progress of the disease. Primary outcome(s): Disease control rate