Treosulfan-fludarabine-thiotepa conditioning before allogeneic haemopoietic stem cell transplantation for patients with advanced lympho-proliferative disease. A single centre study

In recent years, with the aim of reducing transplant-related mortality, new conditioning regimens have been explored in patients not eligible for conventional haemopoietic stem cell transplantation. In this setting, we investigated safety and feasibility of the treosulfan-fludarabine-thiotepa combination prior to allogeneic haemopoietic stem cell transplantation in patients with advanced lympho-proliferative diseases and at high transplant risk. Twenty-seven consecutive patients, median age 43 years (range 19-60), entered this study. All of them were affected by lympho-proliferative disease in advanced phase and have been heavily pre-treated. The median haemopoietic stem cell transplant co-morbidity index was 1 (range 0-3). Twenty-five patients had regular engraftment, while the remaining two patients were not evaluable for early deaths. Non-haematological toxicity was limited. No patient developed veno-occlusive disease. The estimated probability of overall survival and progression-free survival with a median follow-up of 40 months was 52% (95% confidence interval 33-73) and 50% (95% confidence interval 30-70) respectively. Six patients have relapsed; all of them were not in remission before transplantation. The treosulfan-fludarabine-thiotepa combination is a reduced toxicity but myeloablative regimen that can be proposed to patients not fitting criteria for conventional myeloablative transplant regimens. Longer follow-up and prospective randomized studies are necessary to evaluate this regimen.