Survival after stem-cell transplant in pediatric and young-adult patients with relapsed and refractory B-cell acute lymphoblastic leukemia.

OBJECTIVE

Allogeneic stem-cell transplant (allo-SCT) is the standard of care for pediatric patients with acute lymphoblastic leukemia (ALL) who relapse after frontline chemotherapy; however, for patients who relapse after allo-SCT, outcomes are very poor. Few studies have examined overall survival in this patient population, particularly in patients who received a second allo-SCT.

METHODS

This was a retrospective analysis using data from the Center for International Blood and Marrow Transplant Research (CIBMTR) registry. The study population included patients aged 3 to 21 years who were diagnosed with B-ALL and underwent their first allo-SCT between 2009 and 2013. The primary endpoint was the time from the date of posttransplant relapse to the date of death due to any reason.

RESULTS

Outcomes in 1349 pediatric and young-adult patients were included in this analysis. The Kaplan-Meier estimated probability of survival at 3 years after first allo-SCT was 63.1% (95% CI, 60.2%-65.8%). Overall, 29.2% of patients relapsed after first allo-SCT and had a median survival of 7.4 months (95% CI, 6.0-9.6 months). Twenty-five patients in the analysis developed secondary malignancies, most of which were lymphoproliferative disorders.

CONCLUSIONS

Survival rates are low in pediatric and young-adult patients who relapse after first and second allo-SCT, and new therapies are needed to improve outcomes in this population. This data can be used as a historical comparison for single-arm trials of novel therapies for this patient population, including chimeric antigen receptor T-cell therapy.