BC001 Combined TAS-102 in a multicenter phase II clinical study in patients with metastatic colorectal cancer who have failed or not tolerated first-and second-line standard therapy

Interventions: Experimental group:BC001 combined with TAS-102 treatment Primary outcome(s): BC001 Safety of combined TAS-102 in patients with metastatic colorectal cancer who failed or tolerated first-line and second-line standard treatment, including: adverse events, blood routine, blood chemistry and urine routine, physical examination, vital signs and electrocardiogram results. Study Design: Single arm