Dendritic cell-based immunotherapy in multiple myeloma

Most patients with multiple myeloma (MM) cannot be cured with currently available therapies. Although complete remission could be achieved in about 50% of newly diagnosed patients with high-dose chemotherapy and tandem transplantation, relapses of the underlying disease occur frequently. To realize long-term disease-free survival, it will be necessary to develop complementary therapies that are non-cross-resistant with chemotherapy. To this end, immunotherapy aimed at inducing or enhancing tumor-specific immunity that may control or eradicate remaining tumor cells may be an appealing method. Dendritic cells (DCs) are professional antigen-presenting cells and considered the best natural adjuvants for immunotherapy in malignancies. Vaccination with tumor antigen-pulsed DCs has been shown to be protective and therapeutic in animal tumor models, and induced a strong tumor-specific immunity and durable tumor regression in human solid tumors and B-cell lymphoma. As a result, clinical trials in various human malignancies have been initiated. This review will focus on DC-based immunotherapy in MM. I will discuss myeloma antigens and antigen-specific immune responses, the capacity of DCs to present myeloma antigens and induce cytotoxic T-cell responses, and clinical experience of DC vaccination in myeloma patients.