A Baltimore-modified non-TBI conditioning for allogeneic stem cell transplantation in elderly or unfit patients with haploidentical or mismatched donors

Abstract Background: The Baltimore conditioning regimen is nowadays one of the most used reduced-intensity conditioning (RIC) regimens, although access to total body irradiation (TBI) may be challenging in some centers.

Objective

The aim of this study was to evaluate the outcomes following a non-TBI modified Baltimore RIC regimen consisting of fludarabine, cyclophosphamide and busulfan (FE2B2) in allogeneic stem cell transplantation (Allo-SCT) with haploidentical or mismatched unrelated donor (MMUD) transplantation, with post-transplant high-dose cyclophosphamide-based graft-versus-host disease (GVHD) prophylaxis. Study Design: We conducted a non-interventional, monocentric, retrospective cohort study at a tertiary care center (Grenoble-Alpes University Hospital). We included adult patients (> 18 years) who received an HLA haploidentical or a MMUD allogeneic peripheral blood stem cell graft with a non-TBI modified Baltimore conditioning regimen. The primary endpoint of the study was overall survival (OS) at 2- and 5-years post transplantation. Secondary endpoints were donor engraftment, progression-free survival (PFS), non-relapse mortality (NRM), GVHD-free, relapse-free survival (GRFS), and the incidence of acute and chronic GVHD at 2- and 5-years post-transplantation.