BCL-2 disruption during CAR T cell production augments potency through non-apoptotic adaptive changes

Further, long-term in vivo treatment with venetoclax results in transcriptional alterations of signaling pathways involved in T cell activation and exhaustion resistance. Herein, we investigate whether this venetoclax-induced T cell reprograming can be employed to improve the efficacy of adoptive T cell therapy. Using murine and human CD19-targeted chimeric antigen receptor (CAR) T cell therapy (CD19CART) as a model, we show that venetoclax treatment during expansion of CD19CARTs prepared from T cells isolated from healthy donors and patients exhibit enhanced antitumor efficacy in vitro and in vivo using pre-clinical xenograft models of lymphoma and leukemia.

Mechanistically, bulk and single-cell RNA sequencing analyses reveal that venetoclax treatment during CART manufacturing transcriptionally reprograms CART cells at key T cell signaling (JAK/STAT5, PI3K/AKT, NFKB) and metabolic (PGC1α, OXPHOS, glycolysis) pathways to enhance CAR T cell fitness and durability, mechanisms dependent upon BCL-2 affinity to venetoclax. Our study highlights a possible novel therapeutic approach to induce adaptive anti-apoptotic reprograming to enhance the efficacy of CAR T cell therapy and supports the continued examination of BH3 mimetics as immune modulators.