A Study to Evaluate the Efficacy and Safety of Hetrombopag Olamine Tablets Vs Placebo in Patients With Chemotherapy-Induced Thrombocytopenia

Inclusion Criteria: 1. Male or female gender, age ≥18 years at screening. 2. Histologically or cytologically confirmed solid tumor (e.g., non-small-cell lung carcinoma \[NSCLC\], breast, ovarian, bladder, pancreatic, gastrointestinal, or colon/colorectal cancer). 3. Receiving platinum- and/or gemcitabine-containing chemotherapy regimens on 21-day treatment cycles. 4. Eastern Cooperative Oncology Group performance status (ECOG PS) 0-2. 5. Life expectancy ≥6 months. 6. Signed ICF for voluntary participation in the study and good compliance. Exclusion Criteria: 1. Hematopoietic diseases other than CIT (e.g., primary immune thrombocytopenia). 2. Hematologic malignancies. 3. Thrombocytopenia caused by reasons other than chemotherapy, including but not limited to chronic liver disease, hypersplenism, infection, and hemorrhage, within 6 months prior to Study Day 1. 4. Untreated brain metastases; or with leptomeningeal metastasis. 5. Conditions that require emergent treatment (e.g., superior vena cava syndrome, spinal cord compression). 6. Severe cardiovascular disorders or interventions within 6 months 7. Have arterial/venous thrombosis within 6 months 8. Known bleeding disorders, platelet dysfunction 9. Severe haemorrhage during screening 10. Acute or uncontrolled hepatitis B\&C infection 11. Human immunodeficiency virus (HIV) infection.