Novel agents for multiple myeloma with extramedullary disease

Multiple myeloma (MM) is the second most common hematological malignancy. The introduction of proteasome inhibitors (PIs) and immunomodulatory drugs (IMiDs) greatly improved the outcomes for these patients. Extramedullary disease (EMD), an aggressive manifestation of MM, remains a significant treatment challenge. Recently, active clinical development of remarkable novel agents for MM with new mechanisms of action has begun. These agents show promising anti-MM effects and provide the opportunity to extend the survival of patients. They include next-generation PIs and IMiDs; monoclonal antibodies; chimeric antigen receptor T cells; antibody-drug conjugates; bispecific T cell engager antibodies; and small molecular inhibitors. However, few clinical trials have focused on patients with EMD, and the effectiveness of these agents has not been well evaluated and compared in these patients. In this review, we summarize the efficacy of these novel agents in MM patients with EMD.