Chimeric antigen receptor (CAR) T cells have demonstrated success in treating select hematological malignancies, but their activity in solid tumors has been comparably modest. Challenges specific to treating solid tumors include trafficking and distribution throughout the tumor site, overcoming the immunosuppressive tumor microenvironment (TME), and identifying antigenic targets that are widely expressed and indispensable to tumor biology. In this issue of the JCI, Tian et al. describe the use of bicistronic CAR T cells that target multiple antigens expressed in neuroblastoma to overcome antigenic heterogeneity. Combining this approach with interventions that enhance T cell trafficking and prevent acquired dysfunction in the TME may lead to a long-awaited breakthrough in the clinical implementation of CAR T cells for the treatment of solid tumors.
Ayush Pant, Christopher M. Jackson