Trasplante alogénico de células progenitoras hematopoyéticas en pacientes con mielofibrosis: resultados del Grupo Argentino de Trasplante de Médula Ósea (GATMO)

In a multicenter retrospective study, we evaluated the outcome of patients with myelofibrosis (MF) who underwent allogeneic hematopoietic stem cell transplantation (AHCT) in Argentina. A total of 43 patients were included (median age 53; range 23-70; males 56%) who received an AHSCT between 2002 and 2016 in 12 centers; 33 patients had primary MF and 10 patients MF secondary to PV or ET. Donors were related in 30 cases and full match in 38 cases, and the source of stem cells was peripheral blood for all patients. Conditioning regimen was myeloblative (MAC; n=16; Bu ≥9.6 mg/kg) or reduced intensity (RIC; n=27; 13 Bu, 10 Mel and four TBI based). 1-year cumulative incidence of acute grade 2-4 graft versus host disease (GVHD) was 49% and chronic GVHD 11% and the corresponding relapse incidence was 20% (higher in patients with a high DIPSS PLUS; p=0.015). 100-days and 1-year nonrelapse mortality (NRM) was 19% and 37% respectively with the GVHD being the main cause of death. 1-year overall survival (OS) was 55%; in the multivariate analysis pre-transplant factors associated with inferior OS were the HCT-CI (p=0.019), splenomegaly ≥10 cm (p=0.021) and the leukemic transformation (p=0.019). Patients with low HCT-CI (n=17) had better 1-year OS with MAC (MAC vs RIC: 83% vs 41%; p=0.025) whereas those with intermediate-high HCT-CI (n=23) had an inferior 1-year OS with MAC (MAC vs RIC: 22% vs 69%; p=0.040). Our data show that NRM is the main determiner of OS in patients with MF. We should make efforts to control the GVHD and the related infections.