Addition of the neurokinin 1 receptor antagonist aprepitant to standard antiemetic therapy improves control of chemotherapy-induced nausea and vomiting. Results from a randomized, double-blind, placebo-controlled trial in Latin America.

BACKGROUND: Aprepitant is a novel neurokinin 1 (NK(1)) antagonist that has been shown to improve control of chemotherapy-induced nausea and vomiting (CINV) when added to a standard antiemetic regimen of a 5-hydroxytriptamine-3 antagonist plus a corticosteroid. The authors sought to evaluate further the efficacy and tolerability of aprepitant plus standard therapy in a large clinical trial.

METHODS: This was a multicenter, randomized, double-blind, placebo-controlled, parallel-groups, Phase III study. Patients with cancer who were scheduled to receive treatment with high-dose cisplatin chemotherapy were randomized to receive 1 of 2 treatment regimens; the standard therapy group received intravenous ondansetron 32 mg and oral dexamethasone 20 mg on Day 1, and oral dexamethasone 8 mg twice daily on Days 2-4. The aprepitant group received oral aprepitant 125 mg, intravenous ondansetron 32 mg, and oral dexamethasone 12 mg on Day 1; oral aprepitant 80 mg and oral dexamethasone 8 mg once daily on Days 2-3; and oral dexamethasone 8 mg on Day 4. Patients recorded episodes of emesis, use of rescue therapy, and severity of nausea in a diary. A modified intent-to-treat approach was used to analyze the efficacy data. The primary endpoint was complete response (no emesis and no rescue therapy) during the 5-day period postcisplatin. Treatment comparisons were made using logistic regression models, and reported adverse events and physical and laboratory assessments were used to assess tolerability.

RESULTS: A total of 523 patients were evaluated for efficacy, and 568 patients were evaluated for safety. During the 5 days after chemotherapy, the percentages of patients who achieved a complete response were 62.7% in the aprepitant group (163 of 260 patients) versus 43.3% in the standard therapy group (114 of 263 patients; P < 0.001). For Day 1, the complete response rates were 82.8% for the aprepitant group and 68.4% for the standard therapy group (P < 0.001); for Days 2-5, the complete response rates were 67.7% in the aprepitant group and 46.8% in the standard therapy group (P < 0.001). The overall incidence of adverse events was similar between the 2 treatment groups (72.8% in the aprepitant group [206 of 283 patients] and 72.6% in the standard therapy group [207 of 285 patients]) as were rates of serious adverse events, discontinuations due to adverse events, and deaths.

CONCLUSIONS: In patients with cancer who are receiving high-dose cisplatin-based chemotherapy, therapy consisting of aprepitant (125 mg on Day 1 and 80 mg on Days 2-3) plus a standard regimen of ondansetron and dexamethasone provided superior antiemetic protection compared with standard therapy alone and was generally well tolerated.