Comprehensive clinical-molecular transplant scoring system for myelofibrosis undergoing stem cell transplantation

Allogeneic hematopoietic stem cell transplantation is curative in myelofibrosis and current prognostic scoring systems aim to select patients for transplantation. Here, we aimed to develop a prognostic score to determine prognosis after transplantation itself using clinical, molecular and transplant-specific information of a total of 361 myelofibrosis patients. Of these, 205 patients were used as a training cohort to create a clinical-molecular myelofibrosis transplant scoring system (MTSS), which was then externally validated in a cohort of 156 patients. Multivariable analysis on survival identified age ≥ 57 years, Karnofsky performance status 25 x 10 9 /L prior to transplantation, HLA-mismatched unrelated donor, ASXL1 mutation and non-CALR/MPL driver mutation genotype being independent predictors of outcome. The uncorrected concordance index for the final survival model was 0.723, and bias-corrected indices were similar. Risk factors were incorporated into a 4-level MTSS: low (score of 0-2), intermediate (score of 3-4), high (score of 5), and very high (score of > 5). The 5-year survival according to risk groups in the validation cohort was 83% (95% CI, 71-95%), 64% (95% CI, 53-75%), 37% (95% CI, 17-57%), and 22% (95% CI, 4-39%), respectively (p