Relapsed/Refractory Multiple Myeloma Patients. a Multicenter Retrospective Analysis of Eligibility Criteria for CAR-T Cell Therapy

Background. The overall survival (OS) of multiple myeloma (MM) patients (pts) has improved over the years due to the introduction of several novel drugs, such as proteosome inhibitors (PI), immunomodulatory drugs (IMiDs) and, more recently, anti-CD38 monoclonal antibodies (moAb). Nevertheless, the majority of pts continues to relapse, and MM remains an incurable disease. To date, no standard of care has been established for relapsed/refractory (RR) MM pts who have been exposed to the main anti-myeloma drugs. Currently, these pts have a limited number of available treatment options and represent an unmet medical need. Moreover, the outcome of pts failing standard of care regimens, which is now defined as triple-refractory (including PI, IMiDs and moAb), is poor, with a median progression free survival (PFS) of 3-4 months and OS of 8-9 months. Novel therapeutic strategies with different mechanisms of action are warranted to overcome the natural occurrence of relapse or therapy resistance in RR MM pts. Immunotherapy, especially T-cell based approaches, represents the emerging therapeutic strategy for this subset of pts. Chimeric antigen receptor (CAR)-modified T cells are a promising new therapy approach for triple refractory RRMM. Different constructs and specific CAR-T targets are being studied, but BCMA-directed CAR-T cells have so far provided the most convincing evidence of activity, with one product (idecabtage vicleucel) recently approved by FDA.