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:

  1. Absolute Neutrophil Count (ANC) \> 1.0×10⁹/L, Hemoglobin (Hb) \> 80 g/L;
  2. 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);
  3. 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);
  4. 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.