A Study of Hetrombopag Combined With rhTPO in the Treatment of Cancer Therapy-induced Thrombocytopenia (CTIT) in Solid Tumor Patients.

Inclusion criteria

• Age 18-75 years (inclusive), both sexes eligible.
• Histologically or cytologically confirmed malignant solid tumor (e.g., lung, breast, gastric, colorectal, genitourinary cancers, etc.).
• Currently receiving anti-cancer therapy: chemotherapy, radiotherapy, immuno-chemotherapy, targeted therapy, or combinations.
• Grade ≥3 cancer-therapy-induced thrombocytopenia (PLT <50×10⁹/L).
• ECOG performance status 0-1.
• Estimated life expectancy ≥12 weeks.
• Women of child-bearing potential must have a negative serum pregnancy test within 7 days before first dose and not be breastfeeding; they must agree to use effective contraception from enrollment through 7 days after the last study drug. Men with partners of child-bearing potential must be surgically sterilized or agree to use effective contraception during the same period and must not donate sperm.
• Willing to participate, able to provide written informed consent, and expected to comply with the study protocol.

Exclusion criteria

• Pregnant or breastfeeding women.
• Individuals unable to understand the nature of the study or who have not given informed consent.
• History of any arterial or venous thrombosis (stroke, transient ischemic attack, myocardial infarction, deep-vein thrombosis, pulmonary embolism) or clinical/laboratory evidence of a hypercoagulable disorder.
• Cardiac disease within 3 months before screening: grade 3/4 congestive heart failure, arrhythmia requiring medication, myocardial infarction, conditions predisposing to thrombo-embolism (e.g., atrial fibrillation), or QTc prolongation.
• Thrombocytopenia attributed to: concurrent chemoradiotherapy, non-anti-cancer therapy, oxaliplatin-induced sinusoidal injury, definite immune-mediated thrombocytopenia, severe bleeding symptoms, refractory persistent thrombocytopenia, or bone-marrow involvement proven by biopsy in patients with bone metastases.
• Significant hepatic impairment:

• No liver metastases: ALT/AST > 3 × ULN or TBL > 3 × ULN.
• Liver metastases present: ALT/AST ≥ 5 × ULN or TBL ≥ 5 × ULN.
• Known or anticipated hypersensitivity/intolerance to TPO-receptor agonists or any ingredient of hetrombopag ethanolamine tablets.
• Concomitant use of other agents that may affect platelet count (e.g., traditional Chinese medicines, other thrombopoietic agents, antiplatelet drugs).
• Receipt of any TPO-receptor agonist (eltrombopag, romiplostim, etc.), recombinant human TPO, or recombinant IL-11 within 1 month before screening.
• Platelet transfusion within 3 days before randomization/first dose.
• Any condition that, in the investigator's opinion, renders the patient unsuitable for enrollment.