Serum BCMA: A Novel Prognostic Indicator in Patients with Multiple Myeloma

Background: B-cell maturation antigen (BCMA) is a tumor necrosis factor receptor family member that is expressed on normal and malignant B-cells, including those from patients (pts) with multiple myeloma (MM).

Objective: We have analyzed the relationship between serum BCMA levels and monoclonal (M)-protein levels as well as the relationship of BCMA to response status, progression-free survival (PFS) and OS in a cohort of MM pts.

Methods of Use: Two hundred thirty-three MM pts were evaluated. Kaplan‑Meier survival of MM pts was determined from time of initial serum BCMA to death/last follow-up. Cox-proportional hazards regression was utilized to determine the predictive influence of serum BCMA. ELISA was used to correlate serum BCMA and M-protein levels.

Results: Serum BCMA levels correlated with patient’s clinical status at the time of its determination (P < 0.0001). Pts with > PR had significantly lower serum BCMA levels (median, 11.69 ng/mL) than those with stable and progressive disease (median, 64.17 ng/mL; P < 0.001). Changes in serum BCMA levels correlated with changes in M-protein levels. PFS was longer among pts with serum BCMA levels below than among those with levels above the median (P<.0001). OS of pts whose serum BCMA levels were above the median (≥ 32.6 ng/mL) was significantly shorter than among those whose levels were below the median (P<.0001). In the multivariate analyses, serum BCMA levels significantly correlated with OS (P = 0.0003). In contrast, age, bone disease status, creatinine, hemoglobin, and ISS staging did not correlate with OS.

Conclusion: The results demonstrate that BCMA is a novel serum marker that can be used to follow the course of disease, clinical status, and predict survival for MM pts.