A Multicenter, Open-label, Randomized Controlled Trial Evaluating the Efficacy and Safety of Romiplostim N01 in the Treatment of Thrombocytopenia Associated With Concurrent/Sequential Chemoradiotherapy and Chemotherapy Combined With/Without Immunotherapy in Solid Tumors

Inclusion Criteria: 1. Age:18 to 80 years old (man or female); 2. Confirmed with solid tumor by pathological histology or cytology examination; 3. The patient is undergoing concurrent/sequential radiotherapy ± immunotherapy; 4. During the treatment period, the patient experienced a decrease in platelets, and the platelet count within the last 3 days before enrollment was 25×10\^9/L \< platelet count ≤ 75×10\^9/L; 5. The estimated survival period at screening is ≥ 3 months, and it is expected that the current chemotherapy cycle can be used for ≥ 2 cycles; 6. ECOG 0 - 2; 7. Fully understand and comply with the requirements of this study, and voluntarily sign the informed consent form. Exclusion Criteria: 1. Platelet count ≤ 25×10\^9/L at baseline; 2. The patient has previously received treatments for thrombocytopenia, such as thrombopoietin receptor agonists (TOP-RA), recombinant human thrombopoietin (rhTPO), or rhIL-11, etc.; 3. Patients with hematological disorders, including lymphoma, leukemia, aplastic anemia, primary immune thrombocytopenia, myelodysplastic syndromes, multiple myeloma, and myelodysplastic syndrome, etc.; 4. Have experienced thrombocytopenia due to non-tumor treatment within the past 6 months, including but not limited to EDTA-dependent pseudo-thrombocytopenia, splenomegaly, infection, bleeding, etc.; 5. After red blood cell or erythropoietin (EPO) infusion, hemoglobin is still \< 50g/L, or after granulocyte colony-stimulating factor (G-CSF) treatment, absolute neutrophil count is still \< 1.0×10\^9/L; 6. Have experienced any arterial or venous thrombosis within the past 6 months; 7. Have suffered from severe cardiovascular diseases (such as NYHA cardiac function class III-IV), increased risk of thrombosis-related arrhythmias (such as atrial fibrillation), coronary artery stent implantation, angioplasty, and coronary artery bypass grafting within the past 6 months; 8. Have received platelet transfusion within 5 days before randomization or enrollment; 9. Patients with positive hepatitis C antibody and excessive HCV-RNA detection, positive hepatitis B surface antigen and excessive HBV-DNA detection, patients with severe cirrhosis, positive HIV antibody, or positive syphilis antibody; 10. During screening, for subjects without liver metastasis, alanine aminotransferase (ALT) and aspartate aminotransferase (AST) are ≥ 3 times ULN; for subjects with liver metastasis, ≥ 5 times ULN; 11. Serum creatinine concentration ≥ 1.5 times ULN or eGFR ≤ 60ml/min; 12. Patients who are allergic or intolerant to the active ingredient or excipients of Romiplostim N01 for injection; 13. Planning to get pregnant or in the lactation period; 14. The investigator determines that the patient is not suitable to participate in this trial.