Safety and outcome of allogeneic stem cell transplantation in myelofibrosis

We evaluated the safety and outcome of allo-HSCTs in myelofibrosis (MF).

A total of 27 patients with primary (n = 20) or secondary (n = 7) MF, aged 51 (21-63) yr, transplanted from HLA-matched related (59%) or unrelated (41%) donors were analyzed. Conditioning was reduced in 26 and myeloablative in one patient; and ATG was used in 25. Sources of stem cells were as follows: peripheral blood (21), bone marrow (4) or both (2).

Prognostic factors that adversely affected overall survival (OS) in the multivariate analysis were as follows: recipient age >45 yr (HR = 10.55, P = 0.025) and unrelated donor (HR=3.73, P = 0.026). Post-transplant transfusion dependence adversely affected OS in the univariate analysis: dependence from either both RBCs and platelets (HR = 33.26, P = 0.001) or from either of them (HR = 10.53, P = 0.043). Of 16 JAK2V617F-positive patients evaluated post-transplant, it was eradicated in 69% and decreased in 25%. Acute GVHD III-IV developed in 19% and extensive chronic GVHD in 26% of patients; the relapse in four patients was treated with second allo-HSCT. Spleen decreased in all evaluated patients (n = 24). Fibrotic changes improved or disappeared in 80% of evaluated patients (n = 10).

Allo-HSCT may prolong survival, provide disease regression and improve quality of life in MF, especially in patients ≤ 45 yr transplanted from matched related donors. Achieving transfusion independence post-transplant indicates the favorable outcome.