Haploidentical hematopoietic stem cell transplantation compared to immunosuppressive therapy plus eltrombopag as first-line treatment for severe aplastic anemia patients aged 40-65: a multicenter retrospective study.

Immunosuppressive therapy (IST) plus eltrombopag (EPAG) (IST+EPAG) is the preferred first-line treatment for severe aplastic anemia (SAA) patients over 40 years. However, direct comparison between IST+EPAG and upfront haploidentical hematopoietic stem cell transplantation (HID-HSCT) in this population remains limited. We retrospectively analyzed 123 newly diagnosed SAA patients aged 40-65 who received first-line HID-HSCT (n = 67) or IST+EPAG (n = 56) between 2016 and 2024. Hematological response, survival, and safety were compared. The HID-HSCT group demonstrated superior complete response (CR) rates at 3 months (17.9% vs. 5.4%), 6 months (44.8% vs. 17.9%), and 12 months (64.2% vs. 33.9%) (all P < 0.001). The 3-year overall survival (OS) was comparable between the HID-HSCT and IST+EPAG groups (78.0% vs. 80.3%, P = 0.662), and a landmark analysis conditional on survival to 6 months confirmed comparable subsequent 3-year OS (92.2% vs. 88.9%, P = 0.616). Meanwhile, the 3-year failure-free survival (FFS) was significantly higher in the HID-HSCT group among patients aged 40-49 (82.9% vs. 60.1%, P = 0.045), whereas no difference was observed in those aged 50-65 (P = 0.984). HID-HSCT may offer more durable benefits in selected SAA patients aged 40-49, while its advantage over IST+EPAG is not evident in patients aged 50-65.