Purpose: We assessed the efficacy of aprepitant (APR) or 10 or 5 mg OLN (OLN10 or OLN5) plus ondansetron and dexamethasone for chemotherapy-induced nausea/vomiting (CINV) prophylaxis in patients receiving high-emetogenic chemotherapy (HEC).

Methods: Patients who received doxorubicin + cyclophosphamide or cisplatin were given intravenous ondansetron and dexamethasone prior to chemotherapy and oral dexamethasone on days 2-4 and randomized 1:1:1 to receive APR125 on day 1 and APR80 on days 2-3 or OLN10 or OLN5 on days 1-4. Matched placebo controls were used. The primary endpoint was no nausea in ≤ 120 h. Secondary endpoints included CINV severity, complete response (CR) rate, adverse effects (AE), and quality of life.

Results: Of 141 patients, 104 received AC and 37 received cisplatin. The no-nausea rates were 33% (APR), 43.2% (OLN10; p = 0.24), and 37% (OLN5; p = 0.87). Grades 2-4 nausea were experienced by fewer patients for OLN10 than for APR (24-120 h, 8.7% vs. 27.7%, respectively; p = 0.02; overall period, 19.6% vs. 40.4%, respectively; p = 0.03). The median visual analog scale nausea score from 24 to 120 h was significantly lower for OLN10 (2.3) than for APR (1.2, p = 0.03). The degrees of vomiting, CR, and AE were similar between the APR and OLN10 groups. CINV was similar between the OLN5 and APR groups.

Conclusions: Nausea was less severe for OLN10 than for APR in patients receiving HEC, but other measures were similar. CINV prevention efficacy was comparable between OLN5 and APR.