OBJECTIVES: Salvage chemotherapy is the standard of care for relapsed or refractory (R/R) Philadelphia-chromosome-negative (Ph−) B-precursor acute lymphoblastic leukemia (ALL), but its efficacy is unsatisfactory. Although blinatumomab showed superiority over salvage chemotherapy in improving overall survival, its cost-effectiveness is not necessarily clear. This study aimed to evaluate the cost-effectiveness of blinatumomab from the payer’s perspective in Japan.

METHODS: A partitioned survival analysis model was developed to predict costs and quality-adjusted life years (QALYs) in blinatumomab and salvage chemotherapy groups. Survival data were derived from the phase III TOWER study. Drug prices for blinatumomab were estimated based on prices in Japan. Other cost parameters were estimated by using the JMDC calims database. Utility weights were estimated based on previous studies. The incremental cost-effectiveness ratio (ICER) of blinatumomab compared with salvage chemotherapy was estimated. Sensitivity analysis (SA) was performed to assess parameter uncertainty.

RESULTS: Compared with salvage chemotherapy, blinatumomab incurred an additional cost of JPY49,254,687 and conferred an additional 0.428 QALY. This resulted in the ICER of JPY115,044,877/QALY gained. SA showed that the parameter with the largest influence was medical costs other than blinatumomab costs in event-free state, and the ICER ranged from JPY2,344,620 to JPY3,190,562/QALY.

CONCLUSIONS: Applying the willingness to pay threshold of JPY15 million/QALY, blinatumomab was not cost-effective compared to salvage chemotherapy. In the future, it would be necessary to incorporate a cost-effectiveness perspective in the pricing of cancer treatment in Japan.