Multiple myeloma and infections in the era of novel treatment modalities

Infections are major cause of morbidity and mortality in patients with multiple myeloma. Current treatment landscape of newly-diagnosed multiple myeloma includes different classes of drugs, such as proteasome inhibitors, immunomodulatory drugs, and monoclonal antibodies, all of which are characterized by specific risk and pattern of infectious complications. Additionally, autologous and allogeneic hematopoietic cell transplantation, widely used in the treatment of multiple myeloma, are complex procedures, carrying a significant risk of complications, and mainly infections. Finally, novel treatment modalities such as bispecific T-cell engagers and chimeric antigen receptor T-lymphocytes have been changing the paradigm of myeloma treatment in relapsed-refractory setting. These agents due to unique mechanism of action carry distinct pattern of infectious complications. In this review, an attempt has been made to summarize the incidence, risk factors, and patterns of infections during different stages of myeloma treatment including novel treatment modalities, and to provide evidence underlying the current concept of infectious disease prophylaxis in this category of patients.