Phase I Clinical Study of MBS301 in Treatment of HER2 Positive Recurrent or Metastatic Malignant Solid Tumor

Inclusion Criteria: 1. Patients with HER2-positive recurrent or metastatic malignant solid tumor diagnosed by histopathology or cytology. 2. Patients with any types of malignant solid tumors who have progressed despite standard therapy or are intolerant of standard therapy, or for which no standard therapy exists. 3. Patients should have measurable lesions or immeasurable lesions (according to RECIST 1.1). 4. ECOG physical condition: 0 or 1 point. 5. Expected survival period exceeds 12 weeks. Exclusion Criteria: 1. Absolute neutrophils count (ANC) is less than1.5×109/L and/or blood platelets less than 100 ×109/L and/or hemoglobin less than 9g/dL. 2. Total bilirubin is more than 1.5 ×ULN. 3. Patients without hepatic metastasis, ALT or AST is more than 1.5 ×ULN; Patients with hepatic metastasis, ALT or AST is more than 3 ×ULN. 4. Serum creatinine is more than 1.5 × ULN or estimated creatinine clearance \<50 mL/min(according to Cockcroft-Gault). 5. International normalized ratio (INR) is more than 1.5 × ULN or activated partial thromboplastin time (APTT) is more than 1.5 × ULN. 6. Patient has prior treated with anthracyclineswhich accumulated dose is equivalent to adriamycin≥360mg/m2. 7. Patient has been experienced toxic reactions after previous anticancer therapy and has not recovered to Grade 0 or Grade 1 (except for hair loss). 8. Known a history with brain metastasis. 9. Have a history of liver disease of clinical significance. 10. Known to be human immunodeficiency virus (HIV) positive.