ITK-targeted immune remodeling enhanced the efficacy of anti-CD19 CAR-T cell therapy

Abstract Despite the promising efficacy of anti-CD19 CAR-T cells in treating B-cell lymphoma, T cell dysfunction and exhaustion remains a critical barrier to achieving durable responses. Based on the immunomodulatory effect in the clinical trial enrolled lymphoma patients, this study aims to explore the potential of the first in class highly selective ITK inhibitor soquelitinib in enhancing the persistence and antitumor functionality of CAR-T cells. We employed flow cytometric analysis to characterize T cell populations, RNA sequencing for gene expression profiling, and tumor bearing mice models to evaluate therapeutic efficacy. Our results demonstrated that the cytotoxic and anti-tumor activities of CAR-T cells were significantly increased post ITK inhibition treatment through elevation of cytotoxic and effector molecules, such as GZMB, TNF-α and IFN-γ. Meanwhile, soquelitinib promoted the expansion of CD8 + naïve and effector T cells while preventing exhaustion, as indicated by the downregulation of exhaustion markers such as TIM3, LAG3, and PD-1. Additionally, ITK inhibitor-treated CAR-T cells also exhibited increased cytotoxicity against malignant B cells and prolonged survival in tumor-bearing mice. Importantly, the modulation of transcription factors like TOX and TCF1 suggested a delay in T cell exhaustion and maintenance of effector functions. These findings provide a compelling rationale for the integration of clinical stage ITK inhibitor soquelitinib with CAR-T therapy, highlighting its potential to improve treatment outcomes in hematological malignancies and solid tumors.