The study consists of five sequential periods:
* Screening (≤ 4 weeks) * Correction phase * Maintenance phase (first treatment cycle, Cycle 1) * Observation phase (second treatment cycle, Cycle 2) * Follow-up Eligible subjects are gynaecological-cancer patients who developed ≥ grade-2 cancer-therapy-induced thrombocytopenia (CTIT) after anti-tumour therapy, i.e. platelet count \< 75 × 10⁹/L.
* Stage 1\*\* - Prospective, multicentre, randomised clinical study (to inform the confirmatory stage 2) \*\*Cohort 1 (n = 30)\*\* Correction: hetrombopag 7.5 mg p.o. daily until PLT ≥ 100 × 10⁹/L. Within 24 h after completion of Cycle 1 anti-cancer therapy (end of chemotherapy if combined; otherwise end of investigational product on that day) restart hetrombopag 7.5 mg p.o. daily and continue until the last day of Cycle 1 (C1D21).
\*\*Cohort 2 (n = 30)\*\* Correction: hetrombopag 7.5 mg p.o. daily until PLT ≥ 100 × 10⁹/L. During Cycle 1, monitor PLT closely; if PLT falls \< 75 × 10⁹/L, initiate hetrombopag 7.5 mg p.o. daily and continue until C1D21.
\*\*Stage 2\*\* - Prospective, multicentre, randomised, controlled clinical study \*(preliminary design; sample size and details will be refined after stage-1 results)\* \*\*Experimental arm (n = 92)\*\* Correction: hetrombopag 7.5 mg p.o. daily until PLT ≥ 100 × 10⁹/L. Restart within 24 h after completion of Cycle 1 therapy and continue daily until C1D21.
\*\*Control arm (n = 92)\*\* Correction: hetrombopag 7.5 mg p.o. daily until PLT ≥ 100 × 10⁹/L. During Cycle 1, monitor PLT; if PLT \< 75 × 10⁹/L, initiate hetrombopag 7.5 mg p.o. daily until C1D21.
\*\*Correction-phase rules\*\* Discontinue hetrombopag once PLT ≥ 100 × 10⁹/L. If after ≥ 14 days of hetrombopag correction PLT remains \< 100 × 10⁹/L and the next treatment cycle has not started, the investigator may resume hetrombopag or institute alternative platelet-enhancing rescue therapy at their discretion.
Female, aged 18-75 years (inclusive).
Histopathologically or cytologically confirmed ovarian, cervical, endometrial, or other gynecologic malignancy.
Thrombocytopenia (platelet count < 75 × 10⁹/L) attributable to anti-cancer therapy, with ≥ 2 further treatment cycles planned.
ECOG performance status 0-1.
Pregnant or lactating women.
Unable to understand the study nature or give informed consent.
History of any arterial or venous thrombosis (stroke, TIA, MI, DVT, PE) or clinical/laboratory evidence of thrombophilia.
Cardiac disease within 3 months before screening: NYHA class III/IV heart failure, symptomatic arrhythmia requiring therapy, MI, arrhythmias increasing thrombotic risk (e.g., atrial fibrillation), or QTc prolongation.