This study was conducted to assess the effectiveness of single-dose combined netupitant and palonosetron (NEPA) compared to multi-day ondansetron (ONDA) in preventing delayed chemotherapy-induced nausea and vomiting (CINV) with melphalan-based conditioning prior to autologous stem cell transplant (ASCT).
This retrospective cohort study included ASCT patients conditioned with melphalan-based regimens at a teaching hospital in Australia who received either single-dose NEPA (intervention), or multi-day ONDA (historical control). Sample size calculations determined that 108 patients were required. Patients were matched on conditioning regimen, gender, age and malignancy type. Demographics, presence of nausea, incidence of vomiting and doses of rescue medicine were collected for each patient within 24- 120 hours post melphalan. The primary outcome was total control (no vomiting/no nausea/no rescue medicines). Secondary outcomes included complete response (no vomiting/no rescue medicines), doses of rescue medicine, number of emetic episodes and time to first rescue medicine. Statistical analysis included the Fischer’s exact test, Mann-Whitney U test and Kaplan Meier/Log-rank analysis.
A total of 108 patients were included in the study (54 patients per group) with comparable baseline characteristics, meeting the target accrual. A statistically significant difference was not detected for total control (NEPA 13%; ONDA 6%; RR=2.33; p= 0.32; CI= 0.69-7.99). NEPA was found to achieve a superior complete response (NEPA 24%; ONDA 7%; RR=3.20 p= 0.03, CI= 1.18-8.90), a lower median number of emetic episodes (p<0.01) and lower median number of breakthrough antiemetic doses (p<0.01). The median time to first rescue medicine was 54 hours in the NEPA group compared to 23.5 hours in the ONDA group (p<0.01).
Although improved total control with NEPA was not found, there were statistically significant differences in complete response, emetic episodes and breakthrough antiemetic doses, in favour of NEPA. These are clinically important outcomes, suggesting NEPA is advantageous in this setting.