© 2016 The Authors. Objective Rolapitant, a novel neurokinin-1 receptor antagonist (RA), was shown to protect against delayed chemotherapy-induced nausea and vomiting (CINV) during the first cycle of moderately emetogenic chemotherapy (MEC) or highly emetogenic chemotherapy (HEC) in randomized, double-blind trials. This analysis explored the efficacy and safety of rolapitant in preventing CINV over multiple cycles of MEC or HEC. Patients and methods Patients in one phase III MEC, one phase II HEC, and two phase III HEC clinical trials were randomized to receive oral rolapitant (180 mg) or placebo in combination with a 5-hydroxytryptamine type 3 RA and dexamethasone. Regardless of response in cycle 1, patients could continue the same antiemetic treatment for up to six cycles. On days 6-8 of each subsequent chemotherapy cycle, patients reported the incidence of emesis and/or nausea interfering with normal daily life. Post hoc analyses of pooled safety and efficacy data from the four trials were performed for cycles 2-6. Results Significantly more patients receiving rolapitant than control reported no emesis or interfering nausea (combined measure) in cycles 2 (p = 0.006), 3 (p < 0.001), 4 (p = 0.001), and 5 (p = 0.021). Over cycles 1-6, time-to-first emesis was significantly longer with rolapitant than with control (p < 0.001). The incidence of treatment-related adverse events during cycles 2-6 was similar in rolapitant (5.5%) and control (6.8%) arms. No cumulative toxicity was observed. Conclusions Over multiple cycles of MEC or HEC, rolapitant provided superior CINV protection and reduced emesis and nausea interfering with daily life compared with control and remained well tolerated.