Interferon-α: A Potentially Effective Treatment for Minimal Residual Disease in Acute Leukemia/Myelodysplastic Syndrome after Allogeneic Hematopoietic Stem Cell Transplantation

In this prospective clinical study, the safety and efficacy of preemptive interferon-α (IFN-α) treatment were investigated and compared with preemptive donor lymphocyte infusion (DLI) in patients who were minimal residual disease (MRD)-positive after allogeneic hematopoietic stem cell transplantation (HSCT). Patients undergoing allogeneic HSCT were eligible if they had acute leukemia or myelodysplastic syndrome and were MRD-positive after HSCT. Patients who were able to receive DLI were assigned to a preemptive DLI group (n = 45); patients who could not or did not agree to receive DLI after HSCT received preemptive IFN-α. A total of 22 patients received preemptive IFN-α; the median treatment duration was 35 days (range, 4 to 180 days). Seven patients relapsed, and 1 patient died from severe pneumonia. The 1-year cumulative incidence of chronic graft-versus-host disease (cGVHD) after intervention was 90.9% for the IFN-α group and 62.9% for the DLI group (P < .001). MRD status after preemptive intervention was comparable in the 2 groups, and the 1-year cumulative incidence of relapse after intervention was 27.3% for the IFN-α group and 35.6% for the DLI group (P = .514). The 1-year cumulative incidence of nonrelapse mortality after intervention was 4.5% for the IFN-α group and 4.4% for the DLI group (P = .985). The 1-year probability of disease-free survival after intervention was 68.2% for the IFN-α group and 60.0% for the DLI group (P = .517). In multivariate analysis, early-onset MRD, persistent MRD after intervention, and absence of cGVHD after intervention were significantly associated with poorer clinical outcomes. Thus, preemptive IFN-α may be a potential alternative for MRD-positive patients who cannot receive preemptive DLI after HSCT.