Non-myeloablative allogeneic hematopoietic transplantation for patients with hematologic malignancies: 9-year single-centre experience

Matched related and unrelated allogeneic non-myeloablative hematopoietic transplantation (NMT) is increasingly being used in patients with hematologic malignancies. Conditioning regimens and indications for NMT vary considerably from centre to centre. Our institution uses intravenous fludarabine and cyclophosphamide, plus graft-versus-host disease (GVHD) prophylaxis with tacrolimus and mycophenolate mofetil. We retrospectively analyzed 89 consecutive patients who underwent NMT (65 related, 24 unrelated) at our institution from October 2002 to September 2011. The most frequent indications for NMT were acute myelocytic leukemia (high-risk in first complete or subsequent remission: n = 20, 22.5%) and relapsed follicular lymphoma (n = 18, 20.2%). The cumulative incidence of acute GVHD (grades 2-4) was 28.1% (n = 25), and rates were similar for related (n = 18, 28%) and unrelated (n = 7, 29%) NMT. At a median follow-up of 22.6 months, the cumulative incidence of chronic GVHD (limited and extensive) was 68% (n = 61): 68.5% (n = 44) for related and 71% (n = 17) for unrelated NMT. The 100-day transplant-related mortality rate was 2.2%: 1.5% for related and 4.2% for unrelated NMT. Of the 89 patients, 30 (33.7%) have relapsed: 41.5% after related and 12.5% after unrelated NMT. Relapse rates were similar in patients with myeloid and lymphoid malignancies (36.4% vs. 33.3%). The 3-year overall and progression-free survival rates were 50.0% and 43.4% respectively, with multivariate analysis showing that neither rate was affected by age, disease group, status at transplantation, or related compared with unrelated NMT. Our findings indicate that, despite its limitations, including the incidence of chronic GVHD, NMT is an important treatment modality for a selected subgroup of patients with hematologic malignancies.