Comparative clinical effectiveness of various 5-HT(3) RA antiemetic regimens on chemotherapy-induced nausea and vomiting associated with hospital and emergency department visits in real world practice

PURPOSE: The aim of this study was to compare the risk of chemotherapy-induced nausea and vomiting (CINV) events for various 5-HT(3) RAs in patients who received moderately (MEC) or highly emetogenic chemotherapy (HEC) by evaluating hospital or emergency department (ED) admissions. METHODS: PharMetrics claims database was used to identify patients diagnosed with breast cancer (BC) who were initiated on cyclophosphamide-based adjuvant chemotherapy or with lung cancer (LC) initiated on carboplatin-based or cisplatin-based chemotherapy between 2005 and 2008. Patients were stratified in two groups: those initiated and maintained on palonosetron versus those treated with any other 5-HT(3) RA regimens in the 6-month post first chemotherapy. Risk for CINV events, identified by ICD-9-CM for nausea, vomiting, and/or dehydration, were estimated using logistic regressions, controlling for age, gender, comorbidity, and total chemotherapy doses or days. RESULTS: Of the 4,868 cyclophosphamide-treated BC, 5,414 carboplatin-treated LC, and 1,692 cisplatin-treated LC identified, there were 1,864 BC (38.5%), 1,806 carboplatin-treated LC (33.4%), and 390 cisplatin-treated LC (23.0%) in the palonosetron-only group. Palonosetron-only group had significantly lower probability of CINV events associated with ED/hospital admissions in all three cohorts (3.5% vs. 6.3% in BC, 9.5% vs. 13.8% in carboplatin-treated LC, and 16.4% vs. 22.6% in cisplatin-treated LC, all at p < 0.05). Logistic regressions found palonosetron-only group had significantly lower risk of CINV events (odds ratios = 0.550, 0.653, and 0.689 in BC, carboplatin-treated LC and cisplatin-treated LC, respectively, p < 0.05). CONCLUSION: Patients with lung or breast cancer receiving MEC or HEC had significantly lower risk of CINV events associated with hospital/ED admissions if initiated and maintained on palonosetron relative to patients receiving 5-HT(3) RA regimens.