Conditioning with treosulfan and fludarabine for patients with refractory or relapsed non-Hodgkin lymphoma

The treatment of refractory or relapsed non-Hodgkin lymphoma (NHL) remains challenging. In this retrospective study, 88 patients with refractory or relapsed NHL received treosulfan and fludarabine as a reduced-intensity conditioning for allogeneic hematopoietic stem cell transplantation (allo-HSCT). Of the 88 intensely pre-treated patients, 73 experienced a relapse, with 18 of the 88 patients experiencing an early relapse (ER; <6 months from the last chemotherapy). At the time of allo-HSCT, 26 patients were in complete remission (CR) and 43 in partial remission (PR), 12 patients had progressive disease (PD) and 7 had stable disease (SD). A total of 47 patients received an autologous graft followed by allo-HSCT. Following allo-HSCT, 69 of the 88 patients were in CR and 7 were in PR, resulting in an overall response rate of 86.4% (76/88). A total of 33 patients achieved a CR from PR, as did 6 patients from PD and 5 from SD. Of the 88 patients, 43 (49%) were alive at the end of the follow-up period. The patients who directly underwent allo-HSCT without prior auto-HSCT exhibited a better disease-free survival (DFS; P=0.038) with a tendency (P=0.077) for a better overall survival (OS). The patients with ER exhibited a probability of OS of 0.35±0.12 after 3 and 7 years. Chronic graft-versus-host disease (cGvHD) exerted a positive effect on OS and DFS (for limited cGvHD vs. no cGvHD, P=0.002 and 0.004, respectively). In conclusion, allogeneic stem cell transplantation following conditioning with treosufan and fludarabine constitutes a viable therapeutic option for patients with refractory or relapsed NHL and should be considered early during the course of salvage treatment.