This study employs a prospective, multicenter, randomized, two-arm design aimed at evaluating the efficacy and safety of the FTO regimen in preventing delayed chemotherapy-induced nausea and vomiting (CINV) following high-dose chemotherapy for hematopoietic stem cell transplantation (HSCT). A total of 92 patients with multiple myeloma who were indicated for autologous HSCT were enrolled. The primary endpoint was to compare the complete response (CR) rates of the FTO regimen versus the FTD regimen in the delayed phase (24-240 hours after chemotherapy) for preventing nausea and vomiting induced by high-dose chemotherapy during HSCT.

Based on strict inclusion and exclusion criteria, 92 patients with multiple myeloma from 11 hospitals were enrolled. Eligible subjects were randomly assigned in a 1:1 ratio to either the experimental group (FTO regimen) or the control group (FTD regimen).The FTO regimen was administered as follows:Fosaprepitant 150 mg (intravenously every 72 hours starting from the initiation of preconditioning chemotherapy until day +6 after HSCT),Tropisetron 5 mg (intravenously 30 minutes before preconditioning chemotherapy on days -3 to -2),Olanzapine 5 mg (orally once daily at bedtime until day +8 after HSCT, or until the occurrence of an adverse drug event requiring study termination or death, whichever occurred first).The FTD regimen was administered as follows: Fosaprepitant 150 mg (intravenously 30 minutes before chemotherapy on day -3),Tropisetron 5 mg (intravenously 30 minutes before preconditioning chemotherapy on days -3 to -2),Dexamethasone 6 mg (orally 30 minutes before chemotherapy on day -3),and 3.75 mg (orally on days -2 to 0).

The study compared the complete response (CR) rates of the FTO regimen versus the FTD regimen during the acute phase (preconditioning chemotherapy period and 0-24 hours after chemotherapy) and the overall phase (preconditioning chemotherapy period and 0-240 hours after chemotherapy). It also observed and compared the major response (MR), clinical benefit response (CBR), minor response (MiR), and treatment failure (TF) between the two regimens during the acute, delayed, and overall phases. Additionally, the toxic side effects of the FTO and FTD regimens were observed and compared.

Inclusion Criteria:

• Patients with multiple myeloma who are indicated for autologous hematopoietic stem cell transplantation;
• Preconditioning regimen consists of melphalan at a dose of 200 mg/m²;
• ECOG performance status score of 0 to 2;
• Age >18 years and <65 years;
• Expected survival time >3 months;
• Absence of intracranial hypertension, gastrointestinal obstruction, or other causes of refractory vomiting;
• Ability to understand and provide written informed consent.

Exclusion Criteria:

• Presence of nausea or vomiting within 48 hours prior to enrollment, with prior use of antiemetic medications;
• Current use or use within the past month of CYP3A4 inducers, inhibitors, or substrate drugs;
• History of hypersensitivity to fosaprepitant or olanzapine;
• Serum creatinine clearance <60 mL/min;
• Inability to receive treatment and follow-up at the designated study site, or inability to comprehend, comply with the study protocol, or provide informed consent.