This is a prospective, multicenter, real-world study of 500 participants with childhood acute lymphoblastic leukemia who are scheduled to receive dolasetron mesylate injection for prophylaxis against chemotherapy-induced nausea and vomiting.

This study did not make any decision or process intervention for clinical antitumor therapy. The study plans to observe the control of nausea and vomiting within 120 h (D1-D5) after receiving induction chemotherapy and the safety within 7 days (or until this discharge, whichever occurs first).

During the whole study, demographic data, history of motion sickness, ECOG score, complications, name and dosage of anti-tumor therapy drugs, this antiemetic regimen, nausea and vomiting, rescue therapy drugs, combined drugs and adverse events were recorded.

Screening period: D-14~D0 (D1 recorded on the day of chemotherapy drug infusion)

Subjects who planned to receive induction chemotherapy for the first time signed informed consent for this study, completed screening period examination, checked the inclusion criteria before drug infusion, and successfully screened subjects received CINV（chemotherapy-induced nausea and vomiting） prophylaxis regimen including Dolasetron mesylate injection.

Treatment observation period: D1~D5 (beginning of study drug administration - 120 h after chemotherapy drug infusion)

Subjects who met all inclusion criteria and did not meet any exclusion criteria were required to complete pre-chemotherapy CINV prophylaxis 30±10 min before induction chemotherapy drug infusion, as described in the administration protocol. The time of starting infusion of chemotherapy drugs (referring to other chemotherapy drugs except hormone drugs in the chemotherapy regimen) was recorded as 0 h, and the subsequent days were calculated as 24 hours.

Within 120 h after the start of chemotherapy infusion, if the subject had at least one episode of vomiting, retching, or nausea and complained of antiemetic therapy, the investigator evaluated the subject and gave remedial antiemetic therapy, which was determined by the investigator.

Within 120 h after the infusion of chemotherapy drugs, the subject or guardian will fill in the occurrence of vomiting/retching and nausea daily through the subject's diary. If there were any omissions in the subjects' diaries, the researchers would remind the subjects to fill in the contents through phone calls and wechat.

Follow-up period: D6~D7 (or until this discharge, whichever occurs first)

Adverse events were collected from D6 to D7 after chemotherapy drug infusion began (or until this discharge, whichever occurred first), and the relevant data were recorded in the study medical records and EDC（Electronic Data Capture） system.

Inclusion Criteria:

1. Age 2~17 years old
2. The diagnosis of acute lymphoblastic leukemia was analyzed by comprehensive examination of bone marrow cell morphology, immune typing, cytogenetics and molecular biology.
3. The subjects plan to receive induced remission therapy such as VDLP/VDLD+CAM, multicenter CCCG ALL 2015 protocol, SCCCG-ALL-2023 protocol, etc. according to Guidelines for Diagnosis and Treatment of Childhood acute lymphoblastic Leukemia (2018 Edition) for the first time
4. Eastern Cooperative Oncology Group (ECOG) performance status (PS) score 0-2
5. Expected to survive for more than 3 months
6. Subject or guardian can read, understand and complete subject diary.

Exclusion Criteria:

1. Allergic to Dolasetron mesylate injection and its excipients
2. Patients with prolonged QTc interval (QT interval ≥460 ms)
3. Other conditions considered by the researchers not to be included in the group.

Nausea and vomiting induced by induction chemotherapy in children with acute lymphoblastic leukemia