Nausea With Vomiting Chemotherapy-Induced

Patients undergoing either an autologous or allogeneic hematopoietic stem cell transplant (HSCT) and receiving preparative chemotherapy experience a considerable amount of chemotherapy-induced nausea and vomiting (CINV). Current strategies at reducing CINV in this patient population are suboptimal due to lack of efficacy and supportive evidence, potential for increased adverse events, and drug-drug and drug-disease contraindications.

A prospective longitudinal cohort study that will assess the effect of a Personalized Medicine (PM) clinic recommendations on pharmacogenetic variation and/or interacting drugs on plasma drug exposure, effectiveness or toxicity of commonly used antidepressant, pain, and antiemetic medications in cancer patients. Such recommendations will entail genotype-guided treatment suggestions while also considering potential DDI, and will be provided to patients during their clinic visit, and referring physicians thereafter. Drug concentration and therapeutic effectiveness will be assessed before (baseline) and 6 months after recommendations have been provided. To assess effectiveness, patient-reported outcomes will be evaluated using validated scales for symptoms of depression, pain and chemotherapy-induced nausea/ vomiting The investigators hypothesize that the pharmacogenetic variation and DDI, if applicable, determine steady state drug concentration and therapeutic response or toxicity of the investigated antidepressant, pain or antiemetic treatments at baseline, while there is a clinically significant reduction or absence of the effect 6 months after the PM clinic recommendations to referring physicians and patients.

Chemo- or radiation-induced nausea and vomiting (CRVN) is one of the most frequent and feared side effects. It is a symptom that is few or not at all evaluated. There is a significant discrepancy between the perception of the CRVN symptom by caregivers and the patient's own experience. At present, there is no real consensus to manage CRVN with medication, and CRVN relief is also the subject of heterogeneous practices. The importance of primary prevention of CRVN, before starting the first treatment sequence, has been highlighted to optimize the action of antiemetic treatments and limit the risk of anticipated nausea and vomiting (NV). The investigators' objective is to objectively assess the risk of CRVN in children/adolescents treated for cancer (and thus effectively prevent this symptom).

The aim of this randomized study is to compare the efficacy and safety of ondanstron weekly with every 3 weeks for the prevention of nausea and vomiting induced by chemotherapy combined with PD-1 blockade.