OBJECTIVES: To evaluate the effectiveness of inotuzumab ozogamicin for the treatment of relapsed or refractory CD22-positive B cell precursor acute lymphoblastic leukaemia (ALL) with no previous allogeneic hematopoietic stem cell transplantation (HSCT) in Portugal.

METHODS: The effectiveness analysis of inotuzumab ozogamicin compared to standard of care (SoC) was based on a state transition Markov model populated with INO-VATE ALL trial data. The model reflects the clinical pathway for patients with relapsed or refractory ALL, being progression-free survival and overall survival dependent on the achievement of complete response (with or without incomplete count recovery) and subsequent possibility of hematopoietic stem cell transplantation (HSCT). Survival of patients with no relapse post-HSTC for 5 years was based on the literature. Pre-progression and veno-occlusive liver disease utilities were based on EQ-5D-3L results from INO-VATE ALL trial. Post-progression and post-HSCT utilities were based on the literature. Age-specific utility adjustments were made according to the Portuguese general population tariffs. One-way and probabilistic sensitivity analyses were used to assess uncertainty.

RESULTS: Compared to SoC, inotuzumab ozogamicin resulted on an average of 3.91 added life years (LY) and 2.89 quality adjusted life years (QALY). Most gains of inotuzumab ozogamicin (98%) are due to the incremental LY on post-HSCT survival. Deterministic sensitivity analyses show that results are robust to most scenarios but sensitive to the parametric extrapolation of post-SCT survival.

CONCLUSIONS: Inotuzumab ozogamicin for the treatment of relapsed or refractory CD22-positive B cell precursor ALL with no previous allotransplantation allows a relevant health gains, when compared to SoC, in the Portuguese setting. Most gains are due to patients undergoing HSCT after achieving complete response with inotuzumab ozogamicin.