Evaluating the Efficacy and Safety of HSK21542 Injection in Chemotherapy-induced Nausea and Vomiting

Inclusion Criteria: 1.18 years of age or older, of either gender; 2\. Has never been treated with chemotherapy regimen and plan to receive asingle day high emetic chemotherapy regimen by intravenous infusion，including but not limited to AC regimen, carboplatin AUC ≥ 4, Camustine\>250 mg/m2, cisplatin, and other treatment options; 3\. Diagnosed with a malignant solid tumor by histology or cytology; 4\. Has an ECOG Performance Status of 0 or 1; 5\. Predicted life expectancy of ≥3 months; 6\. Adequate bone marrow, kidney, and liver function: 1. Absolute neutrophil count ≥ 1.5 × 109/L, white blood cell count ≥ 3.0 × 109/L; 2. Platelet count ≥ 75 × 109/L; 3. Hemoglobin ≥ 70 g/L; 4. Aspartate transaminase (AST) ≤ 3 × ULN (≤ 5 × ULN in patients with hepatocellular carcinoma or liver metastasis); 5. Alanine transaminase (ALT) ≤ 3 × ULN (≤ 5 × ULN in patients with hepatocellular carcinoma or liver metastasis); 6. Serum total bilirubin ≤ 2 × ULN (≤ 3 × ULN for patients with hepatocellular carcinoma or liver metastasis); 7. Creatinine ≤ 2 × ULN; 7\. Subjects who agree to participate in the trial and voluntarily sign the Informed Consent Form (ICF); Exclusion Criteria: 1. History or evidence of any of the following diseases prior to screening: 1. Suffering from primary or metastatic malignant tumors of the central nervous system; 2. Suffering from epilepsy, Parkinson\'s disease, or other central nervous system disorders that cause nausea and vomiting; 3. Suffering from intestinal obstruction or other digestive system diseases that may cause nausea and vomiting as determined by researchers; 4. Suffering from clearly diagnosed vestibular dysfunction other than motion sickness (including but not limited to peripheral vestibular syndrome, central vestibular syndrome, etc.); 5. History of obvious and chronic dizziness; 6. QT interval\>450 ms during screening or taking concomitant medications due to prolonged QT interval or has risk factors for QT interval prolongation or correspon; 2. Allergies or contraindications to the study drugs or other drugs specified in the protocol (including chemotherapy drugs, investigational drugs and mimetics, dorasetron, aripipitan, dexamethasone, etc.) ; 3. Subjects who have experienced nausea, retching, or vomiting before 24 hours of randomization; 4. Subjects who have received abdominal or pelvic radiation therapy within the first 7 days of randomization or plan to receive abdominal or pelvic radiation therapy during the study period; 5. Subjects with a history of drug abuse, drug addiction, or alcoholism within 3 months prior to screening, where alcoholism is defined as consuming \>2 units of alcohol on average daily (1 unit = 360 mL of beer with 5% alcohol, 45 mL of liquor with 40% alcohol or 150 mL of wine); 6. Subjects who have participated in any investigational trial (defined as receiving investigational drug or placebo) within 1 month prior to screening; 7. Female subjects who are pregnant or breastfeeding; female or male subjects of child-bearing potential are unwilling to use contraception throughout the entire study period and for 3 months after the study completion; 8. Subjects judged by the investigator to be unsuitable for participating in this clinical trial for any other factors.