BCMA-CAR-T cell(Takara Bio)

Patients with relapsed/refractory multiple myeloma (R/R MM) receiving chimeric antigen receptor (CAR) T-cell therapy are at high risk of toxicities, including cytokine release syndrome (CRS). The roles of positron emission-tomography computed tomography (PET/CT) in predicting these toxicities remain unclear. We retrospectively studied 62 patients with R/R MM who received B-cell maturation antigen (BCMA) CAR T-cell therapy at our center. Baseline metabolic tumor volume (MTV) of more than 107.2 cm³ and total lesion glycolysis (TLG) exceeding 406.5 were classified as high MTV and high TLG, respectively. Both high MTV (P = 0.008) and high TLG (P = 0.011) were identified as independent risk factors for the development of severe CRS classified as grade 3 to 4. Moreover, the administration of tocilizumab for the treatment of CRS was associated with high MTV (P = 0.005) or high TLG (P = 0.010). Notably, our multivariate Cox models that incorporated either MTV (P = 0.029) or TLG (P = 0.009) along with plasmacytoma types, high-risk cytogenetics, and high bone marrow plasma cell frequencies demonstrated strong predictive capabilities for the 5.3-year long-term OS. Therefore, baseline high MTV or TLG measured by PET/CT are recognized as adverse prognostic indicators for the incidence of severe CRS and poor outcomes in patients with R/R MM undergoing BCMA CAR T-cell therapy.