Immunotheranostics in Solid Tumors: Longitudinal Tracking of Human IL13Rα2 CAR-T Cells In Vivo

Area of Science:

• Immunotherapy
• Oncology
• Biotechnology

Background:

• Chimeric antigen receptor (CAR)-T cell therapy shows limited efficacy against solid tumors.
• Understanding in vivo biodistribution of engineered T cells is vital for improving CAR-T cell therapy.
• The anti-DOTA huC825 reporter system, termed "Thor", offers a novel approach for tracking cells.

Purpose of the Study:

• To integrate the Thor platform into anti-interleukin-13 receptor α-2 (IL13Rα2)-specific CAR-T cells.
• To evaluate the utility of this engineered CAR-T cell system for mapping T cell distribution in a xenograft melanoma model.
• To assess the sensitivity and temporal resolution of the Thor platform for monitoring CAR-T cell kinetics.

Main Methods:

• Engineered anti-IL13Rα2-scFv CAR-T cells expressing huC825 (KLG3BBz-huC825) were developed.
• Detection sensitivity of the Thor platform was evaluated.
• CAR-T cell biodistribution was monitored using weekly 86Y-labeled DOTA PET/CT scans.
• Therapeutic efficacy was assessed in a xenograft mouse model.

Main Results:

• KLG3BBz-huC825 T cells exhibited potent antigen-specific cytotoxicity and cytokine release in vitro.
• The Thor platform demonstrated high sensitivity, detecting as few as 3,000 engineered T cells.
• Spatiotemporal assessment of CAR-T cell kinetics was achieved for up to 7 weeks post-infusion.
• Histopathology corroborated the PET/CT findings.
• Treatment with KLG3BBz-huC825 CAR-T cells resulted in a survival benefit.

Conclusions:

• The Thor platform provides a versatile and highly sensitive method for studying real-time CAR-T cell kinetics in vivo.
• This technology can significantly aid in optimizing CAR-T cell therapy for solid tumors.
• Accurate biodistribution mapping is essential for advancing CAR-T cell-based cancer treatments.