Background: This study assesses CINV events and resource utilization for CINV in pts treated with HEC and carbo with palo-based CINV regimens in a payer database. Methods: The cohort was randomly selected from Inovalon’s MORE2 Research Edition claims database of longitudinal data from US health plans. Pts received 1st line, either HEC (anthracycline plus cyclophosphamide (AC) or cisplatin) or carbo from 1/1/2010 to 3/30/2015. CINV event frequency (CINV events per ICD-9 for nausea and vomiting and CPT codes for hydration) and CINV-related resources were analyzed for the first four cycles. The use of rescue medications could not accurately be determined for this analysis. HEC pts received triple-drug anti-emetics (IV palo/NK-1/dex) and carbo pts received palo-based therapy. Results: HEC consisted of 1,299 pts receiving 4,503 cycles, 97% female, 96% with breast cancer, mean age 53.0 years. 96% pts treated AC, and 4% cisplatin. CINV triple regimens included IV NK-1 in 92% pts. CINV events were documented in 666 (51%) HEC pts, and 1781 (40%) cycles. CINV-related ER events were seen in 7% pts and 2% cycles. CINV-related hospitalizations were seen in 2% pts and 1% cycles. The length of stay averaged 2.82 days per pt (SD: 22.50). Carbo cohort consisted of 288 pts, total 774 cycles, 67% female, 31% ovarian cancer, with mean age 61.8 yrs. CINV regimens included 52% palo/dex (PD); 22% palo/dex/IV NK-1 (PDN); and 10% palo(P). CINV events for the P cohort were 31%, 48% for the PD group and 41% for the PDN group (NS). CINV-related ER events were in 6% pts and 3% cycles and CINV-related hospitalizations were in 4% pts and 1% cycles. Conclusions: For HEC, NCCN and ASCO recommend triple anti-emetic therapy; however CINV event frequencies for HEC pts with palo-based triple drugs are concerning. Carbo is considered moderately emetogenic chemotherapy. Despite the recommendations for either 2 drugs (5-HT3/dex) or 3 drugs, Carbo pts are still receiving monotherapy, and evidence is disappointing for all levels of prophylaxis, indicating need for better anti-emetic regimens.