Efficacy and Safety of Hetrombopag in Preventing Chemotherapy-induced Thrombocytopenia in Gastrointestinal Tumors

Inclusion Criteria: 1. age ≥18 years; 2. pathologically confirmed gastrointestinal tumors (including esophageal cancer, gastric cancer, colorectal cancer, etc.); 3. during the previous chemotherapy cycle (N-1 cycle), patients had a minimum platelet count of ≥75×10⁹/L and at least one high-risk bleeding factor (① history of bleeding; ② previous treatment with platinum agents, gemcitabine, cytarabine, anthracyclines, etc.; ③ tumor cell bone marrow infiltration; ④ previous or ongoing radiotherapy, especially to long bones or flat bones such as the pelvis or sternum); 4. during the current chemotherapy cycle (N cycle), patients have a platelet count of ≥100±25×10⁹/L; 5. undergoing treatment cycles of 14 or 21 days and requiring at least one more cycle of therapy. 6. ECOG score: 0-2 points; 7. Adequate hematopoietic, liver, and kidney function: * Neutrophil count ≥ 1.5 x 10⁹/L * Hemoglobin ≥ 9.0 g/dL * Creatinine clearance ≥ 40 mL/min (Cockcroft-Gault formula) * For patients without liver metastasis, AST and ALT ≤ 2.5 times the upper limit of normal; * Bilirubin ≤ 2 times the upper limit of normal; * APTT and PT ≤ 1.5 times the upper limit of normal 8. Signed informed consent form. Exclusion Criteria 1. Previous use of TPO-RA drugs; 2. Pre-treatment conditions that cause thrombocytopenia, such as hypersplenism or immune thrombocytopenia; 3. History of thrombosis; 4. Hematologic diseases (anemia, leukemia, autoimmune hemolytic diseases, etc.); 5. Major cardiovascular diseases (acute myocardial infarction, cerebral thrombosis, cerebral hemorrhage, etc.); 6. Pregnant or breastfeeding women; 7. Participation in other drug clinical trials within 4 weeks; 8. Poor compliance, unable to cooperate or report treatment responses; 9. Need for other antiplatelet or platelet-enhancing drugs, including traditional Chinese medicine and herbal preparations; 10. Use of prior platelet-stimulating drugs within 5 half-lives before first dose; 11. Platelet transfusion within 3 days before first dose.