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

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 when 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.