(PA-095) Efficacy and Safety of CAR-T Therapy in CNS-MM

Introduction:  Multiple myeloma involving the central nervous system (CNS-MM) is rare, with an incidence of approximately 1%, and is associated with poor prognosis, exhibiting a median overall survival (OS) of less than 6 months. While CAR-T therapy has demonstrated remarkable efficacy in relapsed/refractory multiple myeloma (RRMM), its effectiveness and safety in CNS-MM remain an unmet clinical need.

Methods:   This retrospective study included 19 CNS-MM patients diagnosed between January 2016 and December 2024 across six centers. Diagnosis was based on the International Myeloma Working Group (IMWG) criteria and the 2018 definition by the Brazilian Dias group, incorporating pathological, cerebrospinal fluid (CSF) cytological, and imaging evidence. Treatment response was assessed using IMWG criteria, and overall survival (OS) and progression-free survival (PFS) were calculated via the Kaplan-Meier method.

Results:   A total of 19 CNS-MM patients were included in the study, comprising 5 with primary CNS-MM and 14 with secondary CNS-MM. The median interval from initial MM diagnosis to CNS involvement was 22.70 months. All patients received systemic therapy, with the entire cohort demonstrating a median OS of 4.33 months and median PFS of 3.33 months. Among these, 5 patients received additional CAR-T immunotherapy. The non-CAR-T group (n=14) showed inferior outcomes (median OS: 2.53 months; median PFS: 2.37 months), whereas the CAR-T group, despite limited sample size, exhibited improved survival (median OS: 5.30 months; median PFS: 5.30 months). No severe toxicities (including CRS or ICANS) were observed in any patient.

Conclusions:   CAR-T therapy demonstrates modest efficacy and acceptable safety in CNS-MM, though further optimization of treatment strategies is warranted to enhance clinical outcomes.