A randomized trial of olanzapine versus palonosetron versus infused ondansetron for the treatment of breakthrough chemotherapy-induced nausea and vomiting in patients undergoing hematopoietic stem cell transplantation.

The primary aim of this study was to compare the effectiveness of olanzapine, palonosetron and ondansetron infusion (standard of care) for the treatment of breakthrough chemotherapy-induced nausea and vomiting (CINV) in patients undergoing hematopoietic stem cell transplantation (HSCT).

It was a randomized open-label prospective study. Sixty-two patients were randomized to receive either ondansetron 32-mg infusion over 24 h, or olanzapine wafer 10 mg once daily in addition to ondansetron 8 mg IV three times a day or a single dose of palonosetron 0.25 mg IV instead of ondansetron. All groups were allowed rescue antiemetics. The primary endpoint was a composite outcome of no emesis, no use of rescue medication, and nausea score reduction of ≥50 %. The secondary endpoint was nausea score reduction of ≥50 %. Both endpoints were measured at 24 and 48 h after initiation of the study treatment. Statistical analysis was conducted using a double-sided Fisher's exact test.

The primary endpoint was achieved in 6, 45, and 18 %, and 6, 64, and 18 % of ondansetron versus olanzapine versus palonosetron patient groups at 24 and 48 h, respectively. The secondary outcome was observed in 17, 60, and 62 %, and 35, 71, and 43 % of ondansetron versus olanzapine versus palonosetron patient groups at 24 and 48 h, respectively. Serious adverse drug reactions were not reported in any arms. Time to engraftment was not significantly different between the arms.

Olanzapine was an effective treatment of breakthrough CINV. A single dose of palonosetron significantly reduced nausea up to 24 h.