['We investigated whether aprepitant, a neurokinin-1 antagonist, could decrease chemotherapy-induced nausea and vomiting (CINV) following cisplatin, when a conventional anti-emetic regimen had failed.', 'This was a prospective study (April 2011-April 2012) of patients with lung cancer, treated with cisplatin at the Beijing Cancer Hospital, and initially receiving granisetron, dexamethasone, and metoclopramide as anti-emetics. If patients experienced vomiting of grade ≥2 and required rescue anti-emetic medications during the first cycle, oral aprepitant was added in subsequent cycles (day 1: 125 mg; days 2-3: 80 mg once daily). Acute (day 1) and delayed (days 2-5) nausea and vomiting, use of rescue medications, and occurrence of adverse reactions were monitored after the start of chemotherapy.', 'Twenty-five of 132 patients (18.9 %) were administered aprepitant for secondary prophylaxis against emesis during the second cycle of chemotherapy. The incidences of acute and delayed nausea were 52 and 100 % in the first cycle, but 8 and 72 % in the second cycle. The incidences of acute and delayed vomiting were 20 and 100 % in the first cycle, but 0 and 36 % in the second cycle. No patients required rescue medications or intravenous rehydration during the second cycle. Aprepitant was not associated with additional adverse events.'] Does addition of aprepitant improve protection against cisplatin-induced emesis when a conventional anti-emetic regimen fails?