Next-generation T cell engagers for cancer and autoimmune diseases

T cell-engaging antibody constructs (TCEs) have emerged as a potent modality to treat cancer and autoimmune diseases. Twelve TCEs have been approved by the FDA and EMA for the treatment of hematological malignancies or solid tumors. Despite the varying designs and binding properties, they all lead to robust single-agent efficacy and approvals in refractory or relapsed leukemia, lymphomas, multiple myeloma (MM), small cell lung cancer, EpCAM-expressing cancers or uveal melanoma. Where comparisons can be deduced, TCEs appear to achieve response rates like those obtained with CAR-T cell therapies. Given the success of the first generation of TCEs, considerable attempts are underway to further improve upon this modality. With the goal of expanding TCEs into other malignant and autoimmune indications, and to further enhance efficacy and improve safety, a multitude of novel TCEs are currently in preclinical and clinical development. Here we review the current approaches to developing next-generation TCEs that can widen the therapeutic index, address heterogeneous target expression, and thereby potentially improve efficacy and safety.