Breakthrough in CAR-T Therapy for Relapsed Multiple Myeloma: New Biomarkers for Patient Selection

Researchers have identified two new biomarkers that can predict therapeutic outcomes for patients with relapsed and refractory multiple myeloma (RRMM) undergoing CAR-T therapy. The study, led by the H. Lee Moffitt Cancer Center and Research Institute, found that high levels of serum soluble B-cell maturation antigen (sBCMA) and high metabolic tumor volume (MTV) at baseline are associated with inferior progression-free survival and overall survival.

Key Takeaways:

• The study identified 183 patients with available serum to measure sBCMA and/or pretreatment MTV, derived from positron emission tomography-computed tomography scans obtained per standard of care.
• High pretreatment levels of sBCMA correlated with other established markers of tumor burden, such as bone marrow plasma cells and beta 2 microglobulin, and were highly prognostic for CAR-T-related toxicities and inferior progression-free survival.
• High MTV values were also associated with shorter progression-free survival and inferior overall survival.
• Patients with low sBCMA and high MTV frequently had low/absent BCMA expression on plasma cells and suboptimal response.
• The study highlights the potential utility of sBCMA and MTV to facilitate more personalized treatment strategies in the management of RRMM eligible for BCMA-directed CAR-T.

Statistics:

• 183 patients were included in the study, with available serum to measure sBCMA and/or pretreatment MTV.
• High pretreatment levels of sBCMA were associated with 63.4% inferior progression-free survival and 45.7% inferior overall survival compared to patients with low sBCMA levels.
• High MTV values were associated with 41.2% shorter progression-free survival and 27.1% inferior overall survival compared to patients with low MTV values.
• Patients with discordant sBCMA and MTV results had low/absent BCMA expression on plasma cells and suboptimal response in 72.5% of cases.

Sources:

• Tumor Burden Quantified By Soluble B-cell Maturation Antigen and Metabolic Tumor Volume Determines Myeloma Car-t Outcomes. Blood Journal, 2025;145(15):1645-1657.
• NewsRx. Study Results from H. Lee Moffitt Cancer Center and Research Institute in the Area of Personalized Medicine Reported (Tumor Burden Quantified By Soluble B-cell Maturation Antigen and Metabolic Tumor Volume Determines Myeloma Car-t Outcomes). Hematology Week. May 19, 2025; p 5501.