Cost-effectiveness in Canada of azacitidine for the treatment of higher-risk myelodysplastic syndromes

Abstract

OBJECTIVE Our goal was to determine the economic value of azacitidine in Canada compared with conventional care regimens (ccrs), including best supportive care (bsc) and low- or standard-dose chemotherapy plus bsc in the treatment of higher-risk myelodysplastic syndromes (mdss) and acute myeloid leukemia (aml) with 20%-30% blasts. METHODS The cost-utility model is a lifetime probabilistic Markov model with a 35-day cycle length consisting of 3 health states: mds; transformation to aml with more than 30% blasts; and death. A third-party public payer perspective was adopted. Overall survival was extrapolated beyond the time horizon of the aza-001 trial comparing azacitidine with ccr. Resource use was determined through a questionnaire completed by Canadian hematologists. Utility values were obtained from two studies in which EQ-5D health questionnaire values were mapped from the European Organization for Research and Treatment of Cancer qlq-C30 survey, and SF-6D scores were mapped from the Short Form 12, elicited from 191 and 43 patients in two different trials. RESULTS In the base case, azacitidine had an incremental cost-effectiveness ratio (icer) of $86,182 (95% confidence limits: $69,920, $107,157) per quality-adjusted life year (qaly) gained relative to ccr. Comparing azacitidine with bsc, low-dose chemotherapy plus bsc, and standard-dose chemotherapy plus bsc, the icers were, respectively, $86,973, $84,829, and $2,152 per qaly gained. Results were most sensitive to the utility for azacitidine after 6 months of treatment and to overall survival. CONCLUSIONS The prolonged 9-month median overall survival with azacitidine relative to ccr fills a gap w hen treating patients with higher-risk mds and aml with 20%-30% blasts. The economic value of azacitidine is within the threshold of willingness-to-pay for third-party public payers for oncology treatments in Canada.