Presentation (CTI)

OBJECTIVES: Nab-paclitaxel plus gemcitabine combination therapy (NabP+Gem) is the standard treatment for metastatic pancreatic ductal adenocarcinoma (mPDAC), but its efficacy is unsatisfactory. Although the four-drug combination therapy, NALIRIFOX, showed superiority over NabP+Gem in improving overall survival, it is not approved in Japan and its cost-effectiveness is not necessarily clear. This study aimed to evaluate the cost-effectiveness of NALIRIFOX 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 NALIRIFOX and NabP+Gem groups. The survival data were derived from the phase III NAPOLI 3 study. Drug costs were based on Japanese prices, whereas other cost parameters were estimated using the JMDC claims database. A Lifetime horizon and a discount rate of 2% per year were applied. Utility weights were estimated based on previous studies. An incremental cost-effectiveness ratio (ICER) of NALIRIFOX compared with NabP+Gem was estimated. In addition, sensitivity analyses (SA) were performed to assess heterogeneity, specifically focusing on body size differences, and parameter uncertainty.
RESULTS: Compared with NabP+Gem, NALIRIFOX incurred an additional cost of JPY 2,486,688 and conferred an additional 0.043 QALY. This resulted in the ICER of JPY 57,916,013/QALY gained. SA revealed that the utility value of NALIRIFOX group in progression-free state was the most influential parameter, with the ICER ranging from JPY 36,818,737 to JPY 135,635,903/QALY. Furthermore, scenario analyses focusing on body size differences revealed significant variations in the ICER.
CONCLUSIONS: Applying the willingness to pay threshold of JPY15 million/QALY, NALIRIFOX was not cost effective compared to NabP+Gem. In the future, it would be necessary to incorporate a cost-effectiveness perspective in clinical and health policy decision on cancer treatment in Japan.