A systematic review of outcomes after stem cell transplantation in acute lymphoblastic leukemia with or without measurable residual disease

This systematic literature review compared clinical outcomes post-stem cell transplantation (SCT) among patients with vs. without the measurable residual disease (MRD) pre-transplant. Relevant literature on adults undergoing transplant with known MRD status pre-transplant was extracted from the MEDLINE, Embase, and CENTRAL databases (through 8 May 2018) and oncology conferences (2014-2018) using keywords for acute lymphoblastic leukemia and MRD. Thirty primary studies reporting SCT outcomes were identified. Hazard ratios (HRs) for overall survival indicated that patients with MRD pre-transplant were more likely to die post-SCT vs. patients with no detectable MRD (HR: 1.51-3.856). In post-SCT relapse studies, 16-100% of patients with MRD vs. 0-50% of patients without MRD relapsed. This review found evidence of markedly worse outcomes post-transplant among patients with vs. without MRD pre-transplant, including shorter median survival (overall, relapse-free, and event-free survival), higher risk of death, more relapse events, and decreased likelihood of remaining in hematologic remission.