Allogeneic stem cell transplantation for myelofibrosis in the modern era: single- center outcomes with DIPSS risk stratification

Background To describe post-transplant outcomes in patients with myelofibrosis stratified by the Dynamic International Prognostic Scoring System (DIPSS) risk at transplantation, and to identify clinical factors associated with overall survival (OS) after allogeneic hematopoietic stem cell transplantation (allo-HSCT). Methods We retrospectively analyzed 42 patients with myelofibrosis who underwent allo-HSCT at Samsung Medical Center between 2014 and 2023. OS was estimated using the Kaplan-Meier method and compared via the log-rank test. Exploratory Cox proportional hazards regression analyses were performed to assess independent associations with OS. Results At transplantation, 28 patients (66.7%) had Intermediate (Int-1/2) and 14 (33.3%) had High DIPSS risk. OS differed significantly by DIPSS risk group (log-rank p = 0.0034): the median OS was 15.2 months (95% CI, 7.2–NR) in the Intermediate group versus 6.4 months (95% CI, 3.3–35.1) in the High-risk group. All 14 High-risk patients (100%) died during follow-up, compared with 14 of 28 (50.0%) in the Intermediate group. The 1-year OS was 57.1% versus 28.6%, 2-year OS was 50.0% versus 14.3%, and 3-year OS was 50.0% versus 7.1%, respectively. In an exploratory multivariable analysis adjusting for HCT-CI and donor type, DIPSS High risk remained independently associated with inferior OS (adjusted HR, 2.91; 95% CI, 1.27–6.63; p = 0.011). No other clinical variable, including age (≥ 60 vs. <60 years; p = 0.16 by log-rank), achieved statistical significance. Conclusion DIPSS High-risk disease at transplantation was associated with uniformly poor post-transplant survival in this single-center cohort. These hypothesis-generating findings underscore the importance of transplant timing before progression to high-risk disease, and warrant validation in larger, multicenter studies.