Engineered CXCR3-A expression enhances B7-H3-targeting CAR T cell migration and efficacy against diffuse intrinsic pontine glioma
Edward Z. Song, Andrea Timpanaro, Michael Meechan, Leonel Elena-Sanchez, Lucy Z. Li, Sophie Jamet, Davina Lau, Lily I. Winter, Matthew D. Dun, Jessica Foster, Myron K. Evans, Siobhan S. Pattwell, Vandana Kalia, Surojit Sarkar, Michael C. Jensen, Matthew C. Biery, Nicholas A. Vitanza
Abstract
Diffuse intrinsic pontine glioma (DIPG) is a fatal brainstem tumor desperately in need of better treatments. Chimeric antigen receptor (CAR) T cell therapies for DIPG have demonstrated clinical tolerability and bioactivity, but not universal benefit. A major obstacle is insufficient CAR T cell trafficking to the tumor. As our recent clinical trials have demonstrated locoregional elevation of CXCL10, a ligand of the chemokine receptor CXCR3, here we aim to leverage this CXCL10 upregulation to enhance cell trafficking by engineering our B7-H3-targeting CAR T cells to overexpress CXCR3 variants. We demonstrate that, compared to unmodified B7-H3 CAR T cells, CXCR3-A-modified CAR T cells migrate more efficiently toward CXCR3 ligands in vitro, and when delivered intracerebroventricularly in orthotopic DIPG mouse models, CXCR3-A-modified CAR T cells show enhanced trafficking into the tumor and improved therapeutic efficacy. Overall, our data support the potential for engineering CXCR3-A expression to enhance CAR T cell trafficking and efficacy against DIPG. CAR T cell therapies have been developed to treat paediatric diffuse intrinsic pontine glioma (DIPG), however, clinical efficacy remains limited. Here, the authors report that engineering B7-H3-targeting CAR T cells to express the chemokine receptor CXCR3-A enhances their trafficking and efficacy in DIPG preclinical models.