2ND BONE-MARROW TRANSPLANTATION FOR LEUKEMIA IN UNTREATED RELAPSE

Seven patients with relapsed acute leukemia (4 ANLL, 3 ALL) and one wi th juvenile chronic myelomonocytic leukemia (JCMML) received a second BMT (BMT2). Patients were conditioned with CY/TBI (n = 7) or BU/CY (n = 1) for the first BMT (BMT1), with adequate recovery in all and witho ut the appearance of acute GVHD (n = 3) or with mild forms (grade I, n = 2; grade II, n = 3). Relapse after BMT1 occurred in < 6 months (n = 2), between 6 and 12 months (n = 5) and > 12 months (n = 1), and the interval from BMT1 to BMT2 was < 6 months (n = 1), from 6 to 12 months (la = 5) or > 12 months (n = 2). Conditioning for BMT2 was done in un treated relapse and included combinations of BU/CY (n = 2), CY/TBI (n = 1) or BU 1 mg/kg at intervals of 6 h by mouth on days -7 to -4 and m elphalan 180 mg/m(2) iv on day -2, with the addition; of VP-16 in the patient with JCMML. Two patients died on day +11 with no evidence of r esidual leukemia at autopsy. Six patients engrafted, one of whom had a n uneventful BMT2, but he relapsed 6 months later. The other five deve loped severe acute GVHD (grades III-IV), with a fatal outcome in three cases, while two responded to treatment and are currently alive in co ntinuous CR at 12 and 36 months. All patients had received conventiona l prophylaxis against acute GVHD. It is concluded that second BMT is a suitable therapeutic alternative for some patients and that the combi nation of BU/melphalan has a good antileukemic potential and permits a dequate engraftment in this setting as evidenced by achievement of com plete remission despite being conditioned in relapse. Despite the pres ence of a mixed hematopoietic chimerism at relapse, these patients are at risk of developing severe acute GVHD and intensive prophylactic me asures are required.