Autologous bone marrow transplantation for acute myeloid leukemia in remission or first relapse using monoclonal antibody-purged marrow: results of phase II studies with long-term follow-up

Abstract

One hundred and thirty-eight patients with AML underwent ABMT with monoclonal antibody plus complement-purged marrow between August 1984 and March 1997. One hundred and ten patients were in CR (CR1: 23; CR2/3: 87) and 28 were in first relapse (R1) at ABMT. Preparative regimens included busulfan (16 mg/kg) and CY (120 mg/kg) (n = 93), CY (120 mg/kg over 2 days) with TBI (1200 cGy) (n = 35), and busulfan (16 mg/kg) plus etoposide (60 mg/kg) (n = 10). CR1 patients treated with CY/TBI (n = 7) had 3- and 5-year disease-free survival (DFS) rates of 71% and 57%. CR1 patients treated with BU/CY (n = 12), had 3- and 5-year DFS rates of 45%. Three and 5-year DFS for CR2/3 patients treated with CY/TBI (n = 26) was 23%. Three- and 5-year DFS for patients in CR2/3 treated with BU/CY (n = 55) was 31 and 28%. Three- and 5-year DFS for patients in R1 treated with BU/CY (n = 26) was 37%. In multivariate analysis, increased age was associated with greater risk of death and relapse. For CR2/3 patients, the length of CR1 was a significant predictor of DFS. ABMT performed in CR or R1 results in excellent 5-year DFS and OS. The contribution of purging may require a randomized trial comparing purged vs unpurged stem cell infusions.