Efficacy of triplet antiemetic prophylaxis against chemotherapy-induced nausea and vomiting in patients with soft tissue sarcomas receiving consecutive-day doxorubicin and ifosfamide therapy.

Background: Doxorubicin and ifosfamide (AI) therapy for soft tissue sarcomas (STS) is given as a 5-day continuous-dose chemotherapy regimen, and classified as carrying high emetic risk. The purpose of this study was to evaluate the efficacy of triplet antiemetic prophylaxis, consisting of a 5-HT₃ receptor antagonist, dexamethasone (DEX), and an NK₁ receptor antagonist, against chemotherapy-induced nausea and vomiting (CINV) induced by AI therapy, and to determine the prophylactic antiemetic effect of the addition of olanzapine (OLZ) to this triplet antiemetic prophylaxis in cases of poor antiemesis.

Patients and methods: Patients who received AI therapy for STS between October 2011 and October 2022 were included in this retrospective study. Patients who did not receive the standard triplet antiemetic prophylaxis of granisetron, DEX, and aprepitant were excluded. Primary endpoint was the rate of complete response (CR) and secondary endpoint was the rate of significant nausea prevention during the acute (days 1-6), delayed (days 7-10), and overall (days 1-10) periods. In addition, CR rate and significant nausea prevention during the acute phase were compared before and after the addition of OLZ in patients who received OLZ as antiemetic prophylaxis in the subsequent cycle due to poor antiemetic control.

Results: A total of 58 patients were analyzed. CR rate for all patients was 32.8% in the acute phase, 53.4% in the delayed phase, and 29.3% in the overall period. The significant nausea prevention rate was 19.0%, 43.1%, and 13.8%, respectively. Sixteen patients received additional OLZ as an antiemetic prophylaxis. Their CR rate before and after the addition of OLZ during the acute phase improved significantly, from 6.3 to 43.8% (P = 0.041). The rate of significant nausea prevention tended to improve, from 6.3 to 43.8% (P = 0.077).

Conclusion: Control of CINV with granisetron, DEX, and aprepitant was poor in patients with STS receiving AI therapy. Addition of OLZ to this standard triplet antiemetic prophylaxis may improve CINV control in the subsequent cycle in patients who experience inadequate CINV control during their first cycle of AI therapy.