A Pilot Study Of Preemptive Low-dose Interleukin-2Therapy In Patients Showing Elevated Minimal Residual Disease After Allogeneic Stem Cell Transplantation

Objective:To determine the efficacy and safety of low-dose Interleukin-2(IL-2) administered to patients with elevated minimal residual disease (MRD) after allogenetic hematopoietic stem cell transplantation(allo-HSCT), and to evaluate the survival benefit of this therapy.Method:"We studied37patients who underwent low-dose IL-2treatment between August1,2010to January31,2014at the first affiliated hospital of Zhejiang University. Follow up to March31,2014,we compared the differences of outcomes between groups classified by genius morbid and MRD levels. Also,we explored the safety of IL-2administration.Results:The3-year overall survival(OS),relapse-free survival(RFS) and cumulative occurrence rates were83.4%(95%CI76.5-90.3%),78.5%(95%CI,71.2%-85.8%)and26.5%(95%CI,18.8%-34.2%).Patients stratified in the high-risk group had a lower OS (RR=0.122, p=0.048) and higher cumulative occurrence rates (RR=0.036, p=0.006). Patients with higher MRD before the treatment of IL-2were easier to relapse (RR=3.926, p=0.011.Low-dose IL-2administration was safe. No serious treatment-related adverse events were observed.Conclusions:Preemptive low-dose interleukin-2therapy could be an effective and safe way to eliminate minimal disease and control its recurrence for the patients showing elevated MRD after allo-HSCT.