Superiority of Double over Single Autologous Stem-Cell Transplantation for Newly Diagnosed Multiple Myeloma and Prognostic Impact of Complete Response: Final Analysis of 'Bologna 96' Study

We performed a prospective, randomized study of single (arm A) versus double (arm B) autologous stem-cell (SC) transplantation (ASCT) for younger patients with newly diagnosed multiple myeloma. A total of 321 patients were enrolled in the study and were randomly assigned to receive either a single course of SC-supported melphalan, 200 mg/m2 (MEL-200) (n=163 patients) or MEL-200 followed, 3 to 6 months apart, by melphalan, 120 mg/m2, and busulfan, 12 mg/kg (n=158 patients). As compared with arm A, randomization to receive double ASCT significantly increased the probability to attain at least a near (n) complete response (CR) (33% vs 47%, respectively; P=0.008). Patients who responded to induction therapy had a CR or nCR rate following either single or double ASCT of 73% and 52%, respectively (P=0.010). Both these values were much higher than those observed among patients who failed to respond to induction therapy, whose posttransplantation ≥ nCR rate was 11% in arm A and 12% in arm B (P=0.20). On multivariate analysis, randomization to double ASCT (P