A Clinical Study of Hetrombopag for Prevention of Thrombocytopenia Induced by Gemcitabine Plus Cisplatin in the Treatment of Nasopharyngeal Carcinoma

Inclusion criteria

• 1. Aged 18 to 75 years old, regardless of gender;
• 2. Patients with nasopharyngeal carcinoma confirmed by pathological or cytological examination;
• 3. Currently receiving treatment with the Gemcitabine + Cisplatin (GP) regimen at a 21-day cycle, with the lowest platelet count < 75×10⁹/L in the previous chemotherapy cycle, and expected to maintain the same chemotherapy regimen for at least 2 more cycles;
• 4. Estimated survival time ≥ 12 weeks;
• 5. Eastern Cooperative Oncology Group (ECOG) Performance Status (PS) score of 0-2;
• 6. Laboratory test indicators meeting the following requirements:

• Absolute Neutrophil Count (ANC) > 1.0×10⁹/L, Hemoglobin (Hb) > 80 g/L;
• Renal function: Creatinine (Cr) ≤ 1.5 × Upper Limit of Normal (ULN) or estimated Glomerular Filtration Rate (eGFR) ≥ 60 ml/min (calculated by the Cockcroft-Gault formula);
• Liver function: Total Bilirubin (TBIL) ≤ 1.5 × ULN; Alanine Aminotransferase (ALT) and Aspartate Aminotransferase (AST) ≤ 3 × ULN; (If the patient has intrahepatic cholangiocarcinoma or liver metastasis, total bilirubin ≤ 3 × ULN and transaminases ≤ 5 × ULN);
• Coagulation function: International Normalized Ratio (INR) of Prothrombin Time (PT) ≤ 1.5 × ULN, and Activated Partial Thromboplastin Time (APTT) within the normal range;
• 7. Females of childbearing potential must agree to use contraception during the study and for 6 months after the study ends; non-lactating females are eligible. Males must agree to use contraception during the study and for 6 months after the study ends;
• 8. No participation in other clinical trials of drugs within 4 weeks prior to enrollment;
• 9. Subjects must understand the study details and voluntarily sign the Informed Consent Form (ICF);
• 10. No severe complications such as active massive gastrointestinal bleeding, perforation, jaundice, gastrointestinal obstruction, or non-cancerous fever > 38℃;
• 11. Expected to have good compliance and be able to complete follow-up for efficacy and adverse reactions as required by the protocol.

Exclusion criteria

• 1. Thrombocytopenia not caused by cancer therapy occurring within 6 months prior to screening, including but not limited to hepatic cirrhosis with hypersplenism, infection, and bleeding;
• 2. Having other hematopoietic system diseases besides chemotherapy-induced thrombocytopenia, including leukemia, primary immune thrombocytopenia (ITP), myeloproliferative diseases (MPDs), multiple myeloma (MM), myelodysplastic syndromes (MDS), etc.;
• 3. Complicated with bone marrow involvement or bone marrow metastasis;
• 4. Having received pelvic, spinal radiotherapy or large-field bone irradiation within 3 months prior to screening;
• 5. History of any arterial or venous thrombosis occurring within 6 months prior to screening;
• 6. Clinical manifestations of severe bleeding (such as gastrointestinal bleeding) within 2 weeks prior to screening;
• 7. Severe cardiovascular diseases (e.g., NYHA Cardiac Function Classification Grade III-IV) within 6 months prior to screening, or patients with arrhythmias known to increase thromboembolic risk (such as atrial fibrillation [AF]), history of coronary artery stenting, angioplasty, or coronary artery bypass grafting (CABG);
• 8. Brain tumor or brain metastasis;
• 9. Having received platelet transfusion within 2 days prior to enrollment;
• 10. Having received treatment with recombinant human thrombopoietin (rhTPO), recombinant human interleukin-11 (rhIL-11), or thrombopoietin receptor agonist drugs (such as eltrombopag, avatrombopag) within 5 days prior to screening;
• 11. Patients with known or anticipated allergy or intolerance to the active ingredient or excipients of Hetrombopag Ethanolamine Tablets (excipients include: cellulose-lactose, low-substituted hydroxypropyl cellulose [L-HPC], magnesium stearate, film-coating premix);
• 12. Pregnant or lactating women;
• 13. Patients deemed ineligible for enrollment by the investigator.