Nonmyeloablative allogeneic stem cell transplantation in elderly patients with hematological malignancies: results from the GITMO (Gruppo Italiano Trapianto Midollo Osseo) multicenter prospective clinical trial

This study aimed to evaluate the efficacy of a nonmyeloablative conditioning consisting of fludarabine and TBI in patients aged >= 60 years. A total of 32 patients (median age 62 years; range 60-70) with hematological malignancies were treated with fludarabine (30 mg/m(2) x 3-5 days) and 200 cCy TBI followed by allogeneic hematopoietic stem cell transplantation (HSCT) from a matched-sibling donor. GVHD prophylaxis consisted of cyclosporine and mycophenolate. Neutrophil recovery occurred in all patients at a median time of 16 days (range 9-34). Six patients did not become granulocytopenic. On day +30, 10 patients had > 95% donor chimerism and 19 patients had mixed chimerism. The cumulative probabilities of Grade II-IV acute GVHD and chronic GVHD were 48 and 83%, respectively. Transplant-related mortality at 100 days and 1 year was 6 and 10%, respectively. The probabilities of 2-year overall (OS) and progression-free survival (PFS) were 39 and 35%, respectively. The estimated 2-year probability of OS and PFS for patients in early disease stages were 77 and 64%, respectively, which were significantly higher than the survival and PFS estimates of 0% obtained in patients with advanced disease stages at the time of transplant. Our analysis would suggest that for patients older than 60, this regimen is well tolerated and associated with a low incidence of transplant-related mortality. The leukemic burden at time of transplant has proven to be the most important risk factor for the outcome.