A monoclonal antibody with selectivity for human kappa myeloma and lymphoma cells which has potential as a therapeutic agent.

Abstract

K-1-21 is a monoclonal antibody which binds to human free kappa light chains and recognises a determinant, KMA selectively expressed on kappa myeloma and lymphoma cells. KMA is absent on plasma cells and resting B cells from normal adults but can be detected on some foetal B cells and a small proportion of activated B cells. Expression of KMA is greatest on cycling cells. K-1-21 is an IgG1 antibody that elicits ADCC but will not cap the KMA determinant unless a second ligand is present. K-1-21 has potential for practical application.