Factors Increasing the Risk of Infection in Patients With Multiple Myeloma: From Biology to Prevention

New therapies for multiple myeloma (MM) have improved survival rates but also increased infection risks, particularly during the early treatment of newly diagnosed disease (NDMM) and in cases of relapsed/refractory disease (RRMM). Understanding the factors contributing to Grade ≥3 infections in MM patients and identifying risk factors is critical for implementing effective prevention strategies and reducing infection incidence and severity. These factors can vary based on the disease, the patient's condition, and the anti-MM therapies employed. This review compiles and analyzes the key factors associated with the increased infection risk in MM patients, emphasizing infection rates linked to different treatment regimens and the reasons behind this increased risk. Additionally, it explores whether infection patterns differ according to the types of regimens or treatments used. Clinical trials report an infection risk of approximately 10% to 15% in ND patients with regimens combining immunomodulators (IMiDs), proteasome inhibitors (PIs), and corticosteroids. However, this risk rises above 30% when anti-CD38 monoclonal antibodies-now a cornerstone of MM treatment-are included. For triple-exposed RRMM patients receiving cellular therapies targeting BCMA, the infection risk exceeds 50%. In recent years, predictive models have been developed to assess the risk of Grade ≥ 3 infections in MM patients, enabling the optimization of preventive strategies. Furthermore, expert recommendations have been published to mitigate the incidence and severity of infections in this population. This review consolidates these recommendations and suggests strategies for managing infections in MM patients undergoing treatment.