Purpose: The primary objective was to determine if a single dose of casopitant 90 mg added to ondansetron and dexamethasone would improve the control of chemotherapy-induced nausea and vomiting (CINV) over 0-120 h following initiation of oxaliplatin-based moderately emetic chemotherapy (MEC) compared to ondansetron and dexamethasone alone.
Methods: Patients with colorectal cancer received either casopitant or placebo intravenously (IV) added to ondansetron 8 mg bid oral on study days 1 to 3 and one dose of dexamethasone 8 mg IV given prior to starting the oxaliplatin on day 1. The primary endpoint was the percentage of subjects achieving complete response (CR; no vomiting/retching or use of rescue medication) during 120 h after initiation of chemotherapy in cycle 1.
Results: No difference in the rate of CR was noted in the casopitant group compared to the placebo group for the overall (placebo 85%, casopitant 86%, p = 0.7273), acute (placebo 96%, casopitant 97%), or delayed phases (placebo 85%, casopitant 86%). The average area under curve (0-∞) of casopitant after a single 90-mg IV dose was 8,390 ng h/mL. At 24 h after casopitant 90-mg IV dosing, the plasma casopitant concentration was 24% lower than the values noted in prior studies with 150 mg oral administration, and the plasma exposure of the major metabolite (GSK525060) was 18% lower.
Conclusions: Addition of single-dose casopitant 90 mg IV did not improve the control of CINV at any time during 120 h following initiation of oxaliplatin-based MEC. Excellent control of CINV was achieved in this study population with the combination of ondansetron and dexamethasone alone.
Trial registration: ClinicalTrials.gov NCT00601172.