Abstract: Objective: To observe and assess the efficacy and safety of palonosetron made in China plus Dexamethasone for preventing nausea and vomiting induced by cisplatin-based chemotherapy. Methods: This study was performed as a randomized，clinical control trial. The patients were received a single dose of palonosetron 0.25mg i.v. bolus (treatment group), or tropisetron 2mg i.v. drop (control group), each administered 30 min before initiation of highly emetogenic cisplatin-based (≥50mg/m2) chemotherapy,both with Dexamethasone (16 mg i.v. drop on day 1, 8 mg i.v. drop on day 2, 3) for prophylactic antiemesis. To observe the proportion of patients with a complete response(CR) and emesis-free during the acute phase (0-24h postchemotherapy )、delayed phase (24-120h postchemotherapy ) and both phases (0-120h postchemotherapy )，and administer rescue medication（tropisetron or Methoxychlorproeainamide ) if the patient needed. Results: 72 patients were included in the clinical trail: 35 patients in the palonosetron group and 37 patients in the tropisetron group. CR rates(CRR) were slightly higher (P ＞0.05) for palonosetron 0.25 mg than tropisetron during the acute (0-24 h) (82.9% versus 75.7%, respectively), delayed (24–120 h)( 65.7% versus 43.2%) phases , but CRR were significantly higher (P ＜0.05) for treatment group than control group during the both phases (0-120 h)( 65.7% vs40.5%).The percent of patients emisis-free for treatment group were numerically higher but not statistically different from control group during the acute phase(91.4% vs 83.8%， P＞0.05), but were significantly higher (P ＜0.05) than control group during the delayed and both phases(77.1% versus 48.6% 、74.3% versus 43.2%， P＜0.05).The adverse reaction of two groups patients included mainly headache、constipation、dizzy and Abdominal discomfort, which were very slight and well tolerated for the patients. Conclusions: Conclusions: palonosetron made in China plus Dexamethasone is effective and safe for preventing both acute and delayed nausea and vomiting with highly emetogenic chemotherapy, and it is superior to tropisetron in preventing chemotherapy-induced delayed nausea and vomiting.

Key words: chemotherapy-induced nausea and vomiting, emesis, 5-HT3 receptor antagonist, ondansetron, Palonosetron