Relapsed refractory multiple myeloma with CNS involvement successfully treated with Elranatamab: first reported case

Abstract

Central nervous system (CNS) involvement in multiple myeloma (MM) is a rare and challenging complication associated with poor prognosis and limited treatment options. Emerging T-cell directing therapies, such as bispecific antibodies (bsAbs) and chimeric antigen receptor T cells (CAR-T), have shown remarkable success in treating MM, but their efficacy in CNS involvement remains unclear. Elranatamab, a humanized bispecific antibody targeting B-cell maturation antigen (BCMA) and CD3-expressing T cells, has demonstrated promising results in relapsed refractory MM. However, its efficacy in treating CNS-MM has not been reported. We present a case of a 37-year-old male MM patient with CNS involvement who has been successfully treated with Elranatamab.

Keywords: BCMA; CNS involvement; Elranatamab; bispecific Ab; multiple myeloma.

Figure 1

Timeline of patient treatment schema.

Figure 2

(A) Flowcytometric analyses of CNS fluid at the time of diagnosis showing CD138 positive lambda clonal plasma cells and decreased CD38 positivity after Daratumumab therapy. (B) Flowcytometric analyses of CNS fluid after 2 cycles of Elranatamab showing decreased CD138 positive lambda clonal plasma cells.

Figure 3

PET CT images are showing a complete remission before (on the top) and after (bottom) Elranatamab therapy.