Value of pre-transplant consolidation chemotherapy in adults with acute lymphoblastic leukemia undergoing allogeneic hematopoietic stem cell transplantation without minimal residual disease in first complete remission.

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is recommended for adults acute lymphoblastic leukemia (ALL) with minimal residual disease (MRD) negative during their first complete remission (CR1). However, the role of pre-transplant consolidation chemotherapy remains unclear. We evaluated 78 CR1/MRD-negative patients, the consolidation and non-consolidation groups had similar 5-year OS (74.8% [95% CI: 62.2-87.3%] vs. 74.2% [95% CI: 53.2-95.1%], p = .894), RFS (72.2% [95% CI: 59.6-84.7%] vs. 73.1% [95% CI: 54.2-91.9%], p = .942), CIR (9.4% [95% CI: 9.1-9.7%] vs. 18.9% [95% CI: 17.3-20.4%], p = .376), and NRM (18.4% [95% CI: 17.7-19.0%] vs. 8.0% [95% CI: 7.3-8.6%], p = .375). Multivariable analysis confirmed that high cytogenetic risk independently predicted poor OS and RFS, although pre-transplant consolidation chemotherapy did not predict the prognosis. Based on these findings, we recommend performing transplantation immediately for adult ALL patients after they have achieved CR1/MRD-negative status when there are readily available donors.