Clinical outcomes of myeloablative allogeneic peripheral blood stem cell transplantation for relapsed/refractory...

The aim of this study was to evaluate the efficacy and safety of myeloablative allogeneic peripheral blood stem cell transplantation (allo-PBSCT) in patients with relapsed/refractory T-cell acute lymphoblastic leukemia/lymphoma (R/R T-ALL/LBL), focusing on immune interventions' impact on long-term prognosis.

16 adult patients (≥18 years; 11 male, 5 female; median age 28 years [range 18-50]) with R/R T-ALL/LBL undergoing salvage allo-PBSCT at the Chinese PLA General Hospital between 2013 and 2022 were retrospectively analyzed. All patients were in partial remission (PR) or disease progression (PD) pre-transplant. Primary endpoints were overall survival (OS), progression-free survival (PFS), and relapse rate (RR); secondary endpoints included GVHD incidence and immune intervention efficacy. Median follow-up was 15.5 months (range 2-69).

5 patients (31.3%) survived at last follow-up. At 3-month post-transplantation assessment, 9 patients achieved CR and 5 maintained PR, while 2 patients died of PD within 2 months post-transplant. Among the 14 evaluable patients, CR patients (n = 9) received immunosuppressant tapering without additional intervention: 4 sustained CR, 2 died of relapse, 3 of transplant-related mortality. PR patients (n = 5) underwent initial immunosuppression withdrawal followed by: donor lymphocyte infusions (DLI, n = 3), chemotherapy (n = 1), or DLI + radiotherapy (n = 1). 4 patients ultimately died of relapse, and 1 attained CR. The 1-year OS and PFS were both 56.3%, 1-year RR was 22.1%, and non-relapse mortality rate (NRM) was 27.1%.

Myeloablative allo-PBSCT is a feasible salvage therapeutic option for R/R T-ALL/LBL patients. Furthermore, immune interventions, such as DLI, may improve outcomes, particularly in patients with PR.