Abstract
BACKGROUND
Chimeric antigen receptor (CAR) modified T cell therapy is a promising treatment strategy for cancer therapy. We developed IL-8 receptor-linked CD70CAR (8R-70CAR), aiming to enhance T-cell intratumoral trafficking and persistence, guided by IL-8-secreting tumors. The preclinical results show that 8R-70CAR T cells induce complete tumor regression and long-lasting antitumor immunity, which necessitate further clinical development of this technology.
OBJECTIVE
To assess the toxicity of 8R-70CAR T cells, evaluate in vitro tumor recognition and expansion of the 8R-70CAR T cells, and develop clinically compliant SOPs for the CAR T cell manufacture.
METHODS
The m8R-70CAR (mouse), h8R-70CAR (human), and control CAR were constructed. Toxicology: C57BL/6J mice were intravenously injected with or without 2x106 m8R-70CAR T cells after total body irradiation (5Gy). The body weight, clinical signs, hematology, serum chemistry, serum cytokines, gross pathology, and histopathology of 12 vital organs were evaluated. Tumor recognition: T cells derived from GBM patients were transduced with h8R-70CAR and then co-cultured with CD70+ glioblastoma. INF-g production was measured. Ex vivo expansion: The G-Rex system was utilized for CAR T cell production, and the expansion of h8R-70CAR T cells was assessed by cell count.
RESULTS
No CAR T cell-related toxicity was observed in mouse study. In addition to a robust antitumor reactivity, the h8R-70CAR T cells present an auto-stimulative property that elicits greater ex vivo expansion compared to other CAR T cells tested. An approximately 1200-fold expansion was achieved during the 2 weeks CAR T cell production without additional stimulation, which allows production of the CAR T cells on a clinical trial scale using < 100mL of whole blood.
CONCLUSION
The 8R-70CAR T cells are effective, auto-stimulative, and safe. These properties are fundamental for successful clinical applications in cancer treatment. A phase I trial using the 8R-70CAR T cells in newly diagnosed GBM will be initiated soon.
Point-Of-Care CAR T-Cell Production (ARI-0001) Using a Closed Semi-automatic Bioreactor: Experience From an Academic Phase I Clinical Trial