Antiemetic efficacy of the neurokinin-1 antagonist, aprepitant, plus a 5HT3 antagonist and a corticosteroid in patients receiving anthracyclines or cyclophosphamide in addition to high-dose cisplatin: analysis of combined data from two Phase III randomized clinical trials.
BACKGROUND: The tendency of chemotherapeutic regimens to cause vomiting is dependent on the individual drugs in the regimen. The authors analyzed data combined from 2 Phase III trials to assess the effect of the neurokinin-1 (NK(1)) antagonist aprepitant combined with a 5HT(3) antagonist plus a corticosteroid in a subpopulation receiving > 1 emetogenic chemotherapeutic agent. METHODS: In the current study, 1043 cisplatin-naive patients (42% were women) receiving cisplatin-based (> or = 70 mg/m(2)) chemotherapy were assigned randomly to a control regimen (ondansetron [O] 32 mg intravenously and dexamethasone [D] 20 mg orally on Day 1; D 8 mg twice daily on Days 2-4) or an aprepitant (A) regimen (A 125 mg orally plus O 32 mg and D 12 mg on Day 1; A 80 mg and D 8 mg once daily on Days 2-3; and D 8 mg on Day 4). Randomization was stratified for use of concomitant chemotherapy and female gender. The primary end point was complete response (no vomiting and no rescue therapy) on Days 1-5 (0-120 hours). Data were analyzed by a modified intent-to-treat approach, and logistic regression was used to make treatment comparisons among patients receiving the most frequently coadministered emetogenic concomitant chemotherapy (Hesketh level > or = 3). RESULTS: Among the approximately 13% of patients (n = 81 for A; n = 80 for control) who received additional emetogenic chemotherapy (doxorubicin or cyclophosphamide), the aprepitant regimen provided a 33 percentage-point improvement in the complete response rate compared with the control regimen. Among the general population, the advantage with aprepitant was 20 percentage points. CONCLUSIONS: The current analysis of > 1000 patients from 2 large randomized trials showed that in the subpopulation at increased risk of chemotherapy-induced nausea and vomiting due to concomitant emetogenic chemotherapy, the addition of aprepitant to standard antiemetics improved protection to an even greater extent than in the general study population.