Evolving strategies with immunomodulating drugs and tandem autologous/allogeneic hematopoietic stem cell transplantation in first line high risk multiple myeloma patients.

We prospectively evaluated in high-risk myeloma patients the efficacy and toxicity of tandem autologous hematopoietic stem cell transplantation (auto-HSCT) followed by reduced-intensity conditioning (RIC) and allogeneic (allo)-HSCT with bortezomib and donor lymphocyte infusions introduction after allo-HSCT (group 1). Results were compared with results from tandem auto-RIC-allo-HSCT without bortezomib (group 2). Groups 1 and 2 were compared to matched patients not receiving allo-HSCT from the Intergroupe Francophone du Myélome prospective studies. Allo-HSCT groups included 25 patients (12 in group 1, 13 in group 2). All patients engrafted. There were 8 acute GVHD (7 grade II [3 in group 1], 1 grade III in group 1)] and 11 chronic GVHD (3 limited [in group 1], 8 extensive [1 in group 1]). Matched population included 36 controls for group 1 and 39 for group 2. After a median follow-up of 55 months (range, 3-142 months), median overall survival was not reached in group 1 versus 65 months (51-not reached [NR]) in its matched group (p = 0.027); it was 96 months (49-NR) in group 2 versus 91 months (32-NR) in its matched group (p = 0.77). Median progression-free survival was 49 months (29-NR) in group 1 and was 25 months (range, 21-35 months) in its matched group (p = 0.0045); it was 31 months (22-NR) in group 2 and 28 months (range, 21-40 months) in its matched group (p = 0.0776). Tandem auto-RIC-allo-HSCT including new molecules and immunomodulation after transplantation could be used as a first-line treatment for high-risk myeloma patients.