Cellular Immunotherapy Using Dendritic Cells in Multiple Myeloma: New Concept to Enhance Efficacy

Multiple myeloma (MM) is a clonal B-cell malignancy that is currently incurable with con‐ ventional chemotherapy, even if high-dose chemotherapy with autologous or allogeneic hematopoietic stem cell transplantation (HSCT) and the development of novel molecular target agents have resulted in a marked improvement in overall survival [1, 2]. Allogeneic HSCT, which induces a clinically significant immune-mediated allogeneic graft-versusmyeloma (GVM) effect, has provided the framework for the development of immunothera‐ peutic strategies [3, 4]. To prolong the survival of patients with MM, who are undergoing allogeneic HSCT, a donor lymphocyte infusion can be used successfully as a salvage therapy, which is based on the GVM effect in some cases of MM that relapse after allogeneic HSCT [5, 6]. A clinically significant immune-mediated GVM effect provides the framework for the development of immune-based therapeutic options that use antigen-presenting cells (APCs) with increased potency, such as dendritic cells (DCs), in MM [6].