Health Care Utilization Databases obtained from health system inform outcome for ruxolitinib treatment in patients with myelofibrosis

Ruxolitinib (RUX) is a JAK1/2 inhibitor widely used in patients with myelofibrosis (MF). Here, we provided real-world data on 652 intermediate-2 and high-risk MF patients receiving RUX, by analyzing electronic Health Care Utilization Databases (HCUD) of all individuals that started RUX in three Italian regions (Lombardy, Lazio, and Tuscany) between October 2014 and December 2017. Over 9 years of observation, the median follow-up of the cohort was 36.8 months. HCUD of this cohort provided relevant information, (1) contemporary rate of patients on RUX receiving stem cell transplantation: 10.9%; (2) median time to RUX discontinuation: 31.2 months (95% confidence interval [CI]: 26.4-36); (3) transfusions need in the first 6 months of RUX: no red blood cell (RBC) units in 408 (69%), 1-5 in 172 (29%), ≥6 in 14 (2%); (4) events' incidence rate (×100 person-years) that led to hospital admission: 10.3 for infections, 5.47 for solid tumors, 3.47 for bleeding, 1.56 for thrombosis, and 5.22 for accelerated/blast phase; (5) RUX individual average cost rate in Italy: 30,675 €/year, increasing with worsening Multisource Comorbidity Score (MCS). Finally, the median survival was 48 months (95% CI: 43.2-51.6). In a multivariable Cox model, together with patient-related factors, starting RUX doses below 20 mg every 12 h (BID) were associated with increased mortality (P from 0.007 to <0.001). We report a novel HCUD-based approach to provide critical healthcare information in the field of MF, based on large populations of patients with documented follow-up.