Phase III Trial of Casopitant, a Novel Neurokinin-1 Receptor Antagonist, for the Prevention of Nausea and Vomiting in Patients Receiving Moderately Emetogenic Chemotherapy

PurposeThe purpose of this phase III trial was to evaluate the efficacy and safety of regimens containing casopitant, a novel neurokinin-1 receptor antagonist, for the prevention of chemotherapy-induced nausea and vomiting during the first cycle in patients receiving moderately emetogenic chemotherapy (MEC).Patients and MethodsPredominantly female patients (98%) diagnosed with breast cancer (96%) who were chemotherapy-naïve and scheduled to receive an anthracycline and cyclophosphamide (AC) –based regimen were enrolled onto this multinational, randomized, double-blind, parallel-group, placebo-controlled clinical trial. All patients received dexamethasone 8 mg intravenously (IV) on day 1 and oral ondansetron 8 mg twice daily on days 1 to 3. Patients were randomly assigned to a control arm (placebo), a single oral dose casopitant arm (150 mg orally [PO] on day 1), a 3-day oral casopitant arm (150 mg PO on day 1 plus 50 mg PO on days 2 to 3), or a 3-day IV/oral casopitant arm (90 mg IV on day 1 plus 50 mg PO on days 2 to 3). The primary end point was the proportion of patients achieving complete response (no vomiting/retching or rescue medications) in the first 120 hours after the initiation of MEC.ResultsA significantly greater proportion of patients in the single-dose oral casopitant arm, 3-day oral casopitant arm, and 3-day IV/oral casopitant arm achieved complete response (73%, 73%, and 74%, respectively) versus control (59%; P < .0001). The study did not demonstrate a reduced proportion of patients with nausea or significant nausea in those receiving casopitant. Adverse events were balanced among study arms.ConclusionAll casopitant regimens studied were more effective than the control regimen. Casopitant was generally well tolerated.