tabalumab tabalumab tabalumab (ly 2127399) is an anti-b-cell activating factor (baff) human monoclonal antibody designed for the treatment of autoimmune diseases and b cell malignancies. tabalumab was developed by eli lilly and company. tabalumabmonoclonal antibodytypewhole antibodysourcehumantargetbaffclinical dataatc codenoneidentifierscas number1143503-67-6 nchemspidernoneuniipqp8vh3mjwkeggd10083chemical and physical dataformulac6518h10008n1724o2032s38molar mass146252.08 g·mol−1 ny (what is this?) (verify) a phase iii clinical trial for rheumatoid arthritis was halted in feb 2013. in september 2014, a second phase iii trial focussing on treating systemic lupus erythematosus, was terminated early as the study failed to meet its primary endpoint.