Allogeneic stem cell transplantation in patients with myelofibrosis harboring the MPL mutation

Abstract Introduction Primary and post‐ET/PV myelofibrosis are myeloproliferative neoplasms harboring in most cases driving mutations in JAK2, CALR or MPL , and a variable number of additional mutations in other genes. Molecular analysis represents a powerful tool to guide prognosis and clinical management. Only about 10% of patients with myelofibrosis harbor alterations in MPL gene. No data are available about the transplantation outcome in the specific MPL ‐mutated group. Patients We collected the data of 18 myelofibrosis patients(primary: 14; post‐ET: 4) transplanted in 4 EBMT centers (Hamburg, Paris, Essen, and Hannover) between 2005 and 2016. Results Before the transplant, we explored the molecular profile by NGS and reported the frequency of mutations occurring in a panel of genes including JAK2, MPL, CALR, U2AF1, SRSF2, SF3B1, ASXL1, IDH1, IDH2, CBL, DNMT3A, TET2, EZH2, TP53, IKZF1, NRAS, KRAS, FLT3, SH2B3, and RUNX1 . The 1‐year transplant‐related mortality was 16.5%, 5‐years overall survival and 5‐y relapse‐free survival 83.5%. The only relapse occurred in a patient who harbored mutations in both ASXL1 and EZH2 genes. Conclusion These retrospective data suggest that MPL‐mutated myelofibrosis patients have a favorable outcome after allogeneic transplantation with very low rate of disease relapse (5.5%) in comparison with the available historical controls regarding myelofibrosis in all.