To evaluate the efficacy of Megestrol Acetate Oral Suspension in Preventing Nausea and Vomiting Induced by Highly Emetogenic Chemotherapy in Malignant Solid Tumor Patients

This multicenter, randomized, double-blind, placebo-controlled parallel-group study evaluates the efficacy, safety, and pharmacokinetic profile of megestrol acetate oral suspension in preventing nausea and vomiting induced by highly emetogenic chemotherapy. The trial plans to enroll 132 chemotherapy-naive malignant solid tumor patients scheduled to undergo initial single-day highly emetogenic chemotherapy regimens.

Inclusion Criteria:

1. Age ≥ 18 years, regardless of sex
2. Histologically or cytologically confirmed lung cancer
3. Expected survival ≥ 3 months
4. Female subjects of childbearing potential must have negative serum pregnancy test within 72 hours prior to randomization and must be non-lactating
5. Capable of comprehending and willingly providing signed informed consent form (ICF), and adhering to study requirements/restrictions Exclusion Criteria

1. Received or scheduled to receive concurrent radiotherapy within 7 days prior to enrollment through Day 1-8 of treatment 2. Systemic corticosteroid therapy or sedating antihistamines within 7 days prior to enrollment 3. Poorly controlled serous cavity effusions (pleural/peritoneal/pericardial) 4. Severe cardiovascular diseases within 3 months prior to enrollment 5. Participation in other clinical trials within 30 days prior to enrollment