Abstract
BACKGROUND AND OBJECTIVE: The phase III ALFA-0701 study demonstrated the efficacy and safety of gemtuzumab ozogamicin (GO) versus standard of care (SOC) chemotherapy (daunorubicin and cytarabine) for the treatment of adult patients with de novo CD33+ acute myeloid leukaemia (AML). This study analysed the cost-effectiveness of GO from the perspective of the UK health care payer. METHODS: A cohort state-transition model was developed to estimate direct health care costs and quality-adjusted life-years (QALYs) over a lifetime time horizon from AML diagnosis to death using monthly cycles. Data on complete remission, overall survival, relapse-free survival (RFS), haematopoietic stem-cell transplantation, and adverse events for GO plus SOC versus SOC were obtained from the ALFA-0701 study. Overall survival and RFS were extrapolated beyond the trial horizon using mixture cure models. Unit costs were obtained from standard national sources. Utilities were identified in a systematic literature review. Costs and outcomes were discounted at 3.5%. Analyses were performed for the base-case population, excluding patients with an unfavourable cytogenetic profile, and the overall population. RESULTS: For the base-case and overall populations respectively, incremental per-patient costs (£13,456 and £14,773) and QALYs (0.99 and 0.68) for GO plus SOC versus SOC resulted in incremental cost-effectiveness ratios (ICERs) of £13,561 and £21,819 per QALY gained. The mean probabilistic ICERs were £14,217 and £23,245, respectively. Univariate sensitivity analyses supported the robustness of the results. CONCLUSIONS: The ICERs for both populations met NICE's £20,000-£30,000 willingness-to-pay threshold for medicines and supported the current approval for GO.