A chimeric monoclonal antibody specifically targeting human immunoglobulin light chain (LC)-related fibrils, which may potentially be used in the treatment of light chain-associated (AL) amyloidosis. Upon administration, chimeric fibril-reactive monoclonal antibody 111F4 targets and binds to the amyloid-related, conformational epitope on LC-related fibrils. This inhibits fibrillogenesis, induces an Fc-mediated cellular inflammatory response, increases degradation and elimination of AL amyloidomas, and prevents systemic LC-associated amyloid deposits. In AL amyloidosis the amyloid fibrils are composed of immunoglobulin light chain fragments.