Kappa myeloma antigen (KMA) (KMA)

Kappa myeloma antigen (KMA) is a tumor-specific cell surface antigen found predominantly on the malignant plasma cells of patients with kappa-type multiple myeloma (Boux et al., 1983). It represents a unique conformational epitope of the kappa light chain that is non-covalently associated with the cell membrane, a feature not typically found on normal B cells or healthy plasma cells (Haagen et al., 2006). Because KMA is expressed in approximately 80% of kappa-type myeloma cases and is absent from normal tissues, it serves as a highly specific therapeutic target (Spencer et al., 2019). The primary therapeutic agent targeting this antigen is KappaMab (MDX-1097), a chimeric monoclonal antibody designed to induce antibody-dependent cellular cytotoxicity (ADCC) against the cancerous cells (Hutchins et al., 2017). Clinical studies have explored its use both as a monotherapy and in combination with standard myeloma treatments like lenalidomide (ClinicalTrials.gov, NCT02095639). Targeting KMA offers a precision medicine approach to treating a subset of multiple myeloma patients while minimizing damage to the broader immune system.

Other names

KMAKappa-type myeloma antigenSurface-bound kappa light chainKappa myeloma-associated antigen

Induction of antibody-dependent cellular cytotoxicity (ADCC) and apoptosis upon binding to the KMA epitope on malignant plasma cells.