Health-Related Quality of Life And Economic Analysis of Olanzapine Versus Aprepitant in Preventing Chemotherapy-Induced Nausea and Vomiting in Patients Receiving Highly Emetogenic Chemotherapy in Malaysia

OBJECTIVES: Olanzapine has been shown to be effective in preventing chemotherapy-induced nausea and vomiting (CINV) after highly emetogenic chemotherapy (HEC); however, there is limited work on the impact of CINV on health-related quality of life (HRQoL) and the comparative cost-effectiveness of CINV prophylaxis in the Malaysian context. Therefore, this study was conducted to determine the HRQoL using EQ-5D-5L and the cost-effectiveness of olanzapine compared with aprepitant for CINV prophylaxis in Malaysia using data from a local study.

METHODS: Fifty-nine chemo-naive patients receiving either olanzapine or aprepitant were randomly recruited and completed the EQ-5D-5L before and day 5 after HEC. HRQoL utility scores were analyzed according to the Malaysian valuation set. The economic evaluation was conducted from a healthcare payer perspective with a 5-day time horizon. Quality-adjusted life days (QALD) and the rate of successfully treated patients were used to measure health effects. The incremental cost-effectiveness ratio is assessed as the mean difference between groups' costs per mean difference in health effects. A one-way sensitivity analysis was performed to assess variations that might affect outcomes.

RESULTS: Aprepitant and olanzapine arms' patients had comparable baseline mean HRQoL utility scores of 0.920 (SD = 0.097) and 0.930 (SD = 0.117), respectively; however, on day 5, a significant difference (P value = .006) was observed with mean score of 0.778 (SD = 0.168) for aprepitant and 0.889 (SD = 0.133) for olanzapine. The cost per successfully treated patient in the aprepitant arm was 60 times greater than in the olanzapine arm (Malaysian Ringgit [MYR] 927 vs MYR 14.83). Likewise, the cost per QALD gain in the aprepitant arm was 36 times higher than in the olanzapine arm (MYR 57.05 vs MYR 1.57). Incremental cost-effectiveness ratio of MYR -937.00 (USD -200.98) per successfully treated patient and MYR -391.84 (USD -85.43) per QALD gained for olanzapine compared with the aprepitant-based regimen.

CONCLUSIONS: An olanzapine-based regimen is a cost-effective therapeutic substitution in patients receiving HEC in Malaysia.