BCMA CAR-T therapy as salvage therapy in patients with plasmablastic myeloma.

Objectives: Plasmablastic myeloma (PBM) is a variant of multiple myeloma associated with a poor prognosis. We investigated the efficacy and safety of B-cell maturation antigen (BCMA) chimeric antigen receptor T cell (CAR-T) therapy in patients with PBM.

Methods: The study comprised six patients diagnosed with PBM between January 1, 2023 and December 31, 2023. The patients received BCMA single-target CAR-T therapy or BMCA/CD19 dual-target CAR-T therapy, with some patients undergoing hematopoietic stem cell transplantation before treatment. The median patient age was 55.5 years (range, 41-63). Four patients exhibited high-risk cytogenetic abnormalities.

Results: The objective response rate (ORR) was 83.3%, with four of six patients achieving a complete response or better and three of six achieving a strigent complete response. Two patients exhibited progression-free survival (PFS) of at least 6 months, one of whom succumbed to a pulmonary infection, whereas four patients died of disease progression. Cytokine release syndrome (CRS) was observed in all patients, three of whom experienced grade 3-4 CRS. Two patients experienced grade 1-2 immune effector cell-associated neurotoxicity syndrome. There were no CRS-related deaths.

Conclusion: BCMA CAR-T therapy was safe and effective as a salvage treatment for PBM, and its toxicity was controllable. Future research will examine the use of CAR-T therapy as part of combination regimens.