Effectiveness of aprepitant in addition to ondansetron in the prevention of nausea and vomiting caused by fractionated radiotherapy to the upper abdomen (AVERT)

Purpose Despite a lower risk of nausea and vomiting in patients receiving radiotherapy to the upper abdomen (UA-RINV) with prophylactic 5-HT3 antagonist therapy, patients can still experience UA-RINV. The aim of this multicenter phase II study was to assess effectiveness, safety, and tolerability of protracted dual NK1-receptor and 5-HT3 antagonist prophylaxis against UA-RINV. Methods Patients receiving fractionated radiotherapy with radiosensitizing chemotherapy received oral ondansetron 8 mg po q12 h and aprepitant 125/80/80 mg on a Monday, Wednesday, Friday schedules throughout radiotherapy. The primary outcome was complete response (CR) defined as no vomiting or rescue therapy during the entire observation period of radiotherapy (OP). Nausea, vomiting, and use of rescue medication were recorded in a modified version of the MASCC antiemesis tool completed twice weekly. Results Fifty-five patients were enrolled at 5 sites, 52 of whom were evaluable. 57.7% of patients (30/52, 95% CI 43.2-71.3%) achieved CR on study, with 73.1% (38/52, 95% CI 59.0-84.4%) who did not vomit, and 71.2% (37/52, 95% CI 56.9-82.9%) who did not use rescue medication during the OP. Overall, participants vomited or experienced significant nausea (SN) for an average of 6.8% (95% CI 11.4-21.0) and 8.4% (95% CI 4.2-12.7%) of time on study, respectively. Nausea was common with 32 (61.5%) reporting SN at any time during the OP. Conclusions UA-RINV remains an important morbidity despite the advent of modern radiotherapy. Aprepitant and ondansetron as dosed in this trial was not superior to standard ondansetron monotherapy.