Efficacy of 3-day versus 5-day aprepitant regimens for long-delayed chemotherapy-induced nausea and vomiting in patients receiving cisplatin-based chemotherapy

Background: Chemotherapy-induced nausea and vomiting (CINV) is an ongoing problem. While effectiveness of triplet antiemetic regimens in the delayed CINV phase (24-120 hours after administration of chemotherapy) has been studied, their effectiveness in the long-delayed phase (120-168 hours post-administration) is unknown. We compared the efficacy of 3- and 5-day courses of a triplet antiemetic prophylaxis containing aprepitant (APR) in controlling long-delayed CINV after cisplatin (CDDP)-based chemotherapy.Research design and methods: We obtained patient-level data from a nationwide, multicenter, prospective observational study in Japan. The incidence and timing of CINV after 3- and 5-day APR-containing regimens were compared using inverse probability treatment weighting.Results: The analysis included 380 patients. The incidence rates of long-delayed nausea and vomiting were significantly reduced for the 5-day compared with the 3-day regimen (29.1% vs. 22.2%, p = 0.0042; 6.7% vs. 0%, p < 0.0001, respectively). Among those without CINV, vomiting was not reported after day 2 in the 5-day APR group but increased after day 4 in the 3-day APR group.Conclusion: A 5-day regimen triplet antiemetic prophylaxis with APR decreased long-delayed vomiting compared with a 3-day regimen in patients receiving CDDP-based chemotherapy. However, the 5-day regimen showed no advantage over the 3-day regimen against long-delayed nausea.