OBJECTIVETo study the efficacy and safety of immunotherapy and imatinib mesylate used in early post allogeneic hematopoietic stem cell transplantation (HSCT) for intervention.

METHODSSixty-four chronic myelogenous leukemia (CML) patients received HSCT were analyzed retrospectively based on bcr-abl kinetics post HSCT. Patients were divided into three groups, imatinib group (n = 13), immunotherapy group (n = 20)and combining both group (n = 31). The primary endpoint is molecular response, the second endpoint is side effect related to intervention.

RESULTSThere was no difference among the three groups in converting to bcr-abl negativity (86.0%, 90.0% and 83.9%, respectively, P = 0.126), 4 years cumulative relapse incidence (32.3%, 0% and 16.1%, respectively, P = 0.130) and 4 years OS (90.0%, 89.7%, 83.0%, respectively, P = 0.696). There was a trend of more relapse in Imatinib group than in immunotherapy group (P = 0.052). There were more hematological toxicity in imatinib and combining groups than that in immunotherapy group (30.8%, 38.7%, and 5.0%, respectively, P = 0.001). There was significant difference in the incidence of GVHD among the three groups (P = 0.000), being 95.0%, 0% and 67.7% in immunotherapy, imatinib and combining groups, respectively. Intervention related death occurred in 2 cases, both with discontinuation of CsA, graft failure in another patient with CsA withdrawal. No intervention related death occurred in the other two groups.

CONCLUSIONSAll three regimens can give a quick and durable molecular remission in most of the patients, but side effects are different. The choice of regimen should be balanced with toxicity individually. CsA withdrawal is not the best choice for very early intervention, the long-term effect for patients received imatinib alone without GVHD is needed to be studied.