Cost-effectiveness of Ruxolitinib vs Best Available Therapy in the Treatment of Myelofibrosis in Spain

**Introduction:** Primary myelofibrosis (MF) is a rare hematologic disease belonging to the group of Philadelphia-negative chronic myeloproliferative neoplasms. Identification of the Janus Kinase (JAK) gene mutations inaugurated a new era in the targeted therapy of myeloproliferative diseases. Ruxolitinib is the first JAK1/JAK2 inhibitor specifically approved for the treatment of disease-related splenomegaly or symptoms in adult patients with primary myelofibrosis. The objective of this study was to assess the cost-effectiveness of ruxolitinib vs best available therapy (BAT) in MF patients in Spain. **Methods:** A decision-tree and Markov model were adapted to the Spanish setting to assess the cost-effectiveness of ruxolitinib vs. BAT on a lifetime horizon (≤15 years) from the societal perspective, while healthcare system perspective was included in the one-way sensitivity analysis. The population was assumed to be similar to that of the COMFORT-II clinical trial (CT), which was also the source of treatment efficacy data. BAT composition was derived from the same CT and validated with Spanish experts. Utilities were derived from the COMFORT-I CT. Costs included treatment, management, hospitalizations, emergency and outpatient visits, as well as adverse events and end-of-life costs. Additionally, costs associated to productivity loss were taken into account. Resource use was validated with experts and costs were extracted from Spanish sources. A probabilistic sensitivity analysis was also performed to evaluate the consistency of the results under the uncertainty or variability of the input data. **Results:** Patients on ruxolitinib accumulated 6.1 life years gained (LYGs), resulting in 73% extra life-years compared to patients treated with BAT (3.5LYs gained). Ruxolitinib provided 4.4 quality-adjusted life years (QALYs), with a 99% improvement compared to BAT (2.2 QALYs). This analysis gave an incremental cost of €47 199 per LYG and an incremental cost of €55 616 per QALY gained from the societal perspective. **Conclusions:** Ruxolitinib would be cost-effective in Spain according to the end-of-life criteria defined by the NICE and commonly referred for Spain (cost-effectiveness threshold of €61 500/QALY), in line with results published for other European countries.