Efficacy of antiemetic regimens for highly emetogenic chemotherapy-induced nausea and vomiting: A network meta-analysis

Several regimens have been introduced in clinical practice in the last years to treat chemotherapy-induced nausea and vomiting (CINV). Direct comparative data remain insufficient. Here, we indirectly compared the efficacy and safety of all combinations used for HEC-induced nausea and vomiting. We retrieved randomized controlled trials (RCTs) published in Pubmed, Embase, and Cochrane Library until October 01, 2021. We included II-III RCTs, including adults with any cancer receiving HEC, and compared different antiemetic regimes to prevent CINV. The primary outcome was overall complete response (defined as the absence of CINV from 0 to 120 hrs since chemotherapy); secondary outcomes were acute (absence of CINV 0-48 hrs after chemotherapy) and delayed (48-120hrs) response and adverse events (AEs). A total of 41 RCTs enrolling 15575 patients were included. We classified the different antiemetic regimes into 18 different groups. Overall, 4-drug regimens containing a combination of dexamethasone, second-generation 5HT3 antagonists, NK antagonists, and olanzapine proved to be the most effective regimen in terms of complete response (p-score 0.95, 0.88 respectively, for the 5 mg and 10 mg olanzapine dosage). On the contrary, regimens containing a combination of dexamethasone and 5-HT3 antagonist confirm the poor efficacy in preventing episodes of nausea. In our network meta-analysis, 4-drug regimens displayed the highest probability of efficacy in terms of complete response.