Serum B-Cell Maturation Antigen: A Novel Biomarker to Predict Outcomes for Multiple Myeloma Patients

Michael Ghermezi, Mingjie Li, Suzie Vardanyan, Nika Manik Harutyunyan, Jillian Gottlieb, Ariana Berenson, Tanya M. Spektor, Claudia Andreu-Vieyra, Sophia Petraki, Eric Sanchez, Kyle Udd, Cathy S. Wang, Regina A. Swift, Haiming Chen, James R Berenson

Abstract

B-cell maturation antigen is expressed on plasma cells. In this study, we have identified serum B-call maturation antigen as a novel biomarker that can monitor and predict outcomes for multiple myeloma patients. Compared to healthy donors, patients with multiple myeloma showed elevated serum B-cell maturation antigen levels (P < 0.0001). Serum B-cell maturation antigen levels correlated with the proportion of plasma cells in bone marrow biopsies (Spearman rho = 0.710; P < 0.001), clinical status (P values: 0.0374 complete response vs partial response; < 0.0001 complete response vs. progressive disease), and tracked with changes in M protein levels. Among patients with non secretory disease, serum B-cell maturation antigen levels correlated with bone marrow plasma cell levels and PET scan findings. Kaplan-Meier analysis demonstrated that serum B-cell maturation antigen levels above the median levels were predictive of a shorter progression-free survival (PFS; P = 0.0006) and overall survival (OS; P = 0.0108) among multiple myeloma patients (n = 243). Specifically, patients with serum B-cell maturation antigen levels above the median level at the time of starting frontline (P = 0.0043) or a new salvage therapy (P = 0.0044) were found to have shorter progression-free survival. Importantly, serum B-cell maturation antigen levels did not show any dependence on renal function and maintained independent significance when tested against other known prognostic markers for multiple myeloma such as age, β2M, hemoglobin, and bone disease. These data identify serum B-cell maturation antigen as a new biomarker to manage multiple myeloma patients.