A phase II trial of prophylactic olanzapine combined with palonosetron and dexamethasone for preventing nausea and vomiting induced by cisplatin.

AIM: To investigate the efficacy and safety of olanzapine in combination with palonosetron and dexamethasone for patients receiving cisplatin (≥50 mg/m(2) ), because this antiemetic therapy has not been sufficiently examined in patients receiving cisplatin.

METHODS: We conducted a phase II study to evaluate the efficacy and safety of olanzapine in combination with palonosetron and dexamethasone for chemotherapy naïve patients receiving cisplatin (≥50 mg/m(2) ). Patients received prophylactic dexamethasone (20 mg IV, day 1), palonosetron (0.75 mg IV, day 1), and olanzapine (10 mg, days 1-4). The patients were monitored for emesis and nausea for 120 h after chemotherapy. The primary endpoint was the complete response (CR) rate, which was defined as no vomiting episodes and no use of rescue medication for the overall period. CR rates of 65% and 45% would indicate the potential usefulness and the lower limit of interest, respectively.

RESULTS: Fifty-one patients, including 37 esophageal cancer patients were enrolled, of whom 41 (80%) completed the treatment protocol as planned. The complete response rate for the overall period was 43% (95% confidence interval: 29-58); the primary endpoint was not met. Vomiting was frequently observed, with the overall rate of 51%. Most events occurred during 24-72 h after chemotherapy. Somnolence was observed in 73% of the patients, but it was well tolerated in most cases.

CONCLUSIONS: Olanzapine combined with palonosetron and dexamethasone did not prevent chemotherapy-induced nausea and vomiting induced by cisplatin as expected. The safety of this antiemetic therapy was confirmed.