TAME – CD19-targeted B-cell therapy for post-infectious autoimmune ME/CFS using the monoclonal antibody tafasitamab: open-label follow-up study to a randomized, placebo-controlled Phase II trial of the CD19 antibody inebilizumab

Growing scientific evidence suggests that autoantibodies and dysregulated B cells play a significant role in a subset of ME/CFS patients. In studies—including those conducted at Charité – Universitätsmedizin Berlin—immunoadsorption (the removal of circulating antibodies from the blood) led to marked, though only temporary, clinical improvement in some treated patients; this is likely because the procedure has only a limited effect on the antibody-producing B cells themselves. The targeted elimination of antibody-producing cells using therapeutic monoclonal antibodies is an established treatment strategy for various autoimmune diseases. The TAME project is investigating the CD19 antibody tafasitamab as a potential new treatment for ME/CFS. Tafasitamab targets B cells and plasmablasts involved in the production of disease-relevant autoantibodies. Tafasitamab is being administered as a direct follow-up treatment in a study succeeding the placebo-controlled PIONEER trial (funded by the Federal Ministry for Research, Technology and Space, BMFTR), in which the CD19 antibody inebilizumab was used. The aim is to determine whether tafasitamab can achieve or maintain B-cell depletion and clinical remission as effectively as inebilizumab. While tafasitamab is significantly less expensive than inebilizumab, data regarding its use in autoimmune diseases remain limited. The TAME study will involve 38 patients who previously participated in the PIONEER trial. Depending on their original PIONEER study arm, patients receive tafasitamab under different treatment regimens—either as an initial B-cell-depleting therapy or as maintenance therapy following prior treatment with inebilizumab. The study aims to provide important insights into whether CD19-targeted B-cell therapy is a promising therapeutic approach for an immunologically defined subgroup of ME/CFS.

​