Tumor protective effect was observed in AST-301 group (1506.7±1603.0 mm3) compared with control group (GM-CSF, 1266.3±862.5 mm3) as an immune adjuvant...The groups of AST-301 and AST-301+TZM were significantly higher to the anti-tumor activity than control group, and AST-301 was more effective than AST-301+TZM or TZM alone…. Tumor protective and tumor therapeutic effect of AST-301 were demonstrated well in various doses and regimens on HER2/neu positive gastric cancer xenograft model.