Composition and Methods for Selective Expansion of CAR-T Cells Made in vivo or ex-vivo with the IL9R

Stanford scientists have developed a method to selectively expand CAR-T cells by co-delivering IL9R with CAR genes using a novel platform that enables rapid CAR-T cell engineering through targeted lentiviral delivery. This approach promotes selective expansion of engineered T cells through IL9 cytokine treatment, eliminating the need for traditional lymphodepletion procedures and achieving enhanced anti-tumor efficacy.

Current CAR-T cell manufacturing processes require lymphodepletion prior to infusion to promote CAR-T cell engraftment and expansion in patients. While lymphodepletion creates a favorable microenvironment for CAR-T cell activation and proliferation, it puts patients at significant risk of infections and cytopenia due to the depletion of normal immune cells. Additionally, emerging rapid CAR-T manufacturing platforms enable in vivo engineering but face significant challenges. These approaches cannot utilize traditional lymphodepletion methods, as this would eliminate the T cells targeted for engineering, and the rapid in vivo modification process produces relatively low numbers of CAR-positive T cells compared to conventional manufacturing. Therefore, a method to selectively expand engineered T cells while promoting optimal anti-tumor signaling is essential for successful in-vivo CAR-T cell therapy.

Co-delivering IL9R with CAR genes enables selective expansion of engineered T cells through treatment with IL9, a naturally orthogonal cytokine that specifically targets cells expressing the co-delivered receptor. This approach promotes optimal JAK/STAT signaling for enhanced T cell proliferation and anti-tumor function without affecting non-engineered cells. In preclinical studies, CAR-T cells co-delivered with IL9R demonstrated significantly enhanced expansion and anti-tumor potency compared to CAR alone in leukemia models. Consequently, IL9R co-delivery has the potential to overcome the key limitations of rapid in vivo CAR-T manufacturing by enabling selective expansion without requiring lymphodepletion, offering a safer and more effective approach to CAR-T cell therapy.

Stage of Development
Preclinical: in-vivo
Continued research: Translating the platform to mouse models for toxicity assessment, evaluating in vivo targeting with different binding molecules, and optimizing ex vivo delivery protocols with ultra-short exposure times.