Identification of optimal contemporary antiemetic prophylaxis for doxorubicin-cyclophosphamide chemotherapy in Chinese cancer patients: post-hoc analysis of 3 prospective studies

Objective: Chemotherapy-induced nausea and vomiting (CINV) are common with doxorubicin-cyclophosphamide (AC)chemotherapy. Recommended antiemetic regimens incorporate neurokinin-1 receptor antagonist (NK1RA), 5-hydroxytryptaminetype-3 receptor antagonist (5HT3RA), corticosteroid, and dopamine antagonists. This post-hoc analysis compared results of 3prospective antiemetic studies conducted among Chinese breast cancer patients who received (neo)adjuvant AC, in order to identifyoptimal antiemetic prophylaxis. Methods: A total of 304 patients were included: Group 1, ondansetron/dexamethasone (D1); Group 2, aprepitant/ondansetron/dexamethasone (D1); Group 3, aprepitant/ondansetron/dexamethasone (D1–3); Group 4, aprepitant/ondansetron/dexamethasone(D1–3)/olanzapine; and Group 5, netupitant/palonosetron/dexamethasone (D1–3). Antiemetic efficacies of Groups 3, 4, and 5during cycle 1 of AC were individually compared with Group 1. In addition, emesis outcomes of patients in Groups 3 and 5, andthose of Groups 2 and 3, were compared. Results: When comparing efficacies of a historical doublet (5HT3RA/dexamethasone) with triplet antiemetic regimens(NK1RA/5HT3RA/dexamethasone) with/without olanzapine, complete response (CR) percentages and quality of life (QOL) inoverall phase of cycle 1 AC were compared between Group 1 and the other groups: Group 1 vs. 3, 41.9% vs. 38.3% (P = 0.6849);Group 1 vs. 4, 41.9% vs. 65.0% (P = 0.0107); and Group 1 vs. 5, 41.9% vs. 60.0% (P = 0.0460). Groups 4 and 5 achieved a betterQOL. When comparing netupitant-based (Group 3) with aprepitant-based (Group 5) triplet antiemetics, CR percentages were38.3% vs. 60.0%, respectively (P = 0.0176); Group 5 achieved a better QOL. When comparing 1 day (Group 2) vs. 3 day (Group 3)dexamethasone, CR percentages were 46.8% and 38.3%, respectively (P = 0.3459); Group 3 had a worse QOL. Conclusions: Aprepitant-containing triplets were non-superior to doublet antiemetics. Netupitant-containing triplets and addingolanzapine to aprepitant-containing triplets were superior to doublets. Netupitant/palonosetron/dexamethasone was superior toaprepitant/ondansetron/dexamethasone. Protracted administration of dexamethasone provided limited additional benefit.