A real-world experience of eltrombopag plus rabbit antithymocyte immunoglobulin–based IST in Chinese patients with severe aplastic anemia

Eltrombopag (EPAG), a thrombopoietin receptor agonist, was approved for the treatment of severe aplastic anemia (SAA) combined with immunosuppressive therapy (IST). However, the effects of real-life use of low doses of EPAG combined with rabbit antithymocyte globulin (ATG)-based IST in Asian patients with SAA are yet unknown. A total of 121 previously untreated Chinese patients with SAA were enrolled in a multicenter registry of the Chinese Eastern Collaboration Group of Anemia (2014-2020): 67 patients received IST alone and 54 patients received additional EPAG. Patients receiving IST plus EPAG had a higher overall response rate (ORR) at 1 month (P = 0.002), 3 months (P = 0.028), 6 months (P = 0.006), and 12 months (P = 0.031) compared to those receiving IST alone. EPAG was the favorable factor for response efficacy at 6 months. The complete response rate in the EPAG plus IST group was 17% at 3 months, 27% at 6 months, and 32% at 12 months, compared to 7% (P = 0.069), 14% (P = 0.11), and 33% (P = 0.92) for those treated with IST alone. The 2-year overall survival rate in EPAG plus IST and IST alone groups was 98% and 88%, respectively (P = 0.078). The rate of adverse events, including clonal evolution, infection, and transaminitis, was similar in the two cohorts. The addition of EPAG to IST was well-tolerated and associated with high rates of hematologic responses among the previously untreated Chinese patients with SAA.