Impact of Minimal Residual Disease on Hematopoietic Stem Cell Transplantation in Acute Lymphoblastic Leukemia

Strategic Insights -

Research published in Haematologica has shed light on the impact of minimal residual disease (MRD) on the outcome of hematopoietic stem cell transplantation (HSCT) for childhood acute lymphoblastic leukemia (ALL). The study, conducted within the international phase-III FORUM trial, found that MRD positivity was associated with worse event-free survival (EFS) in patients with pediatric ALL.

Key Takeaways:

  • The FORUM trial, which enrolled 1,014 patients aged 4-21 years, demonstrated that MRD positivity before HSCT was found in 21% of patients.
  • Patients with MRD positivity before HSCT had a significantly lower 3-year EFS rate of 0.47 compared to MRD-negative patients, who had an EFS rate of 0.77 (p<0.001).
  • MRD positivity at day 100 and 1 year after HSCT was also associated with a lower EFS rate, with a trend towards a worse outcome in MRD-positive patients.
  • The study found that MRD negativity before HSCT was associated with a better EFS rate, but the difference was not significant when MRD negativity was assessed at day 100.
  • The research suggests that MRD assessment before HSCT and at day 100 after HSCT is crucial for determining the outcome of HSCT in pediatric ALL patients.
  • The study highlights the importance of developing more effective strategies to reduce MRD in pediatric ALL patients undergoing HSCT.

Statistics:

  • 21% of patients were MRD-positive before HSCT.
  • 3-year event-free survival (EFS) rate was 0.73 for MRD-negative patients and 0.59 for MRD-positive patients before HSCT (p<0.001).
  • At day 100, 3-year EFS rate was 0.77 for MRD-negative patients and 0.47 for MRD-positive patients (p<0.001).

Sources:

  • Impact of minimal residual disease on the outcome of hematopoietic stem cell transplantation for childhood acute lymphoblastic leukemia within the FORUM Trial. Haematologica, 2025,999(1). (Haematologica - http://www.haematologica.org)
  • Haematologica: This journal article is available at https://doi-org.sdpl.idm.oclc.org/10.3324/haematol.2025.287456
  • Adriana Balduzzi, et al. (2025). Pediatric Department, Fondazione IRCCS San Gerardo, Monza, Italy.