OBJECTIVES: Although the INO-VATE trial showed that inotuzumab ozogamicin (InO) is associated with better survival outcomes than SOC in the treatment of patients with relapsed or refractory (R/R) acute lymphocytic leukaemia (ALL), InO comes with a high price tag. As a result, the value of this intervention remains unclear. The purpose of this study was to evaluate the value-based drug price of InO in the treatment of patients with R/R ALL, accounting for drug wastage. This study was conducted according to a U.S. Medicare perspective.

METHODS: A Markov model composed of 3 health states: progression-free, progression, and death was developed and populated from multiple sources, including the INO-VATE trial, to evaluate the costs and utilities associated with each treatment regimen. Transition probabilities for the Markov model were derived after the individual patient data reconstruction from published Kaplan-Meier progression-free and death curves (INO-VATE trial). Drug costs, administration costs, adverse events costs, lab and imaging costs were obtained using Medicare reimbursement rates ($ US 2017) and the literature. Baseline health utilities weights were obtained from the INO-VATE trial. Costs and outcomes were discounted at 3% annually. Sensitivity analyses and drug wastage scenarios were conducted. Incremental cost-effectiveness ratios (ICERs) for InO compared with SoC were estimated and assessed against benchmark willingness to pay thresholds.

RESULTS: The ICER for InO vs SoC was estimated to be 190,829 per QALM under wastage considerations. A threshold analysis established that for InO to be cost-effective considering a WTP of 50,000/QALY, its acquisition should less than $19195 per month. The results of the sensitivity analyses under no wastage considerations suggest that SoC is dominated by InO.

CONCLUSIONS: Drug wastage has a significant influence on the cost-effectiveness of InO when compared with SoC. Further studies are needed to estimate the value-based price of Ino when hematopoietic stem cell transplantation (HSCT) costs are considered.