IL TRAPIANTO DI MIDOLLO OSSEO ALLOGENICO DA DONATORE APLOIDENTICO NEI PAZIENTI CON LINFOMA DI HODGKIN RICADUTO/REFRATTARIO

Background. Disease relapse remains an unmet medical need for patients with Hodgkin lymphoma (HL) receiving an allogeneic hematopoietic cell transplantation (HCT). Methods. With the aim of identifying patients at high risk for post-transplant relapse, we retrospectively reviewed 41 HL patients who had received haploidentical (haplo) non myeloablative (NMA) HCT with high dose post-transplant cyclophosphamide (PT-CY) for graft-versus-host (GvHD) prophylaxis. Primary refractory disease, relapse within 6 months from autologous stem cell transplantation (ASCT), age, pre-transplant chemotherapy, hematopoietic cell transplantation comorbidity index (HCT-CI), sex mismatch, tumor burden and pre-transplant positron-emission tomography (FDG-PET) status, assessed by Deauville score, were analyzed as variables influencing outcomes. Results. All but one patient engrafted: median time to neutrophil and platelet recovery were15 (range 13-23) and 19 (12-28) days, respectively. Cumulative incidence of severe (grade III-IV) acute GvHD and 3-year moderate-severe chronic GvHD was 2.4% and 11.8%, respectively. The 3-year overall (OS), progression free (PFS) and graft relapse free survival (GRFS) were 75.6%, 43.9%, and 39%, respectively. On multivariate analysis, 3-year OS was significantly worse in patients with HCT-CI ≥ 3 (HR 5.0 95% CI 1.1-21.8 p =0.03). Three-year relapse rate , 3-year PFS and 3-year GRFS were significantly worse in patients with HCT-CI ≥ 3 (HR=3.5 95% CI 1.3-9.3 p=0.01, HR=3.3 95% CI 1.2-9.0 p=0.02 and HR=4.2 95% CI 1.7-9.9 p=0.001, respectively) and in patients with a Deauville score ≥ 4 on pre-transplant FDG-PET (HR=4.4 95% CI 1.6-12.4 p=0.005, HR=3.8 95% CI 1.5-9.7 p=0.005 and 3.2 95% CI 1.3-7.9 p=0.01, respectively). On univariate analysis, 3-year NRM was significantly worse only in patients with a HCT-CI ≥ 3 (HR=17.6 95% CI 1.4-221.0). Conclusions. Among relapsed/refractory HL patients undergoing haplo NMA HCT with PT-Cy, pre-transplant FDG-PET with a Deauville score ≥ 4 and HCT-CI ≥ 3 identified patients at high risk of relapse. Moreover, a HCTCI ≥ 3 was associated with higher NRM and lower OS.