Ponatinib inhibits LCK and PI3K signaling and promotes CD8<sup>+</sup> T stem cell memory cell development.

Okuhiro, Yuki; Ito, Sachiko; Watanabe, Keisuke; Yan, Yue; Kumagai, Kazuhiro; Sato, Takahiko; Kojima, Yasuhiro; Fujioka, Yuki et al. · Nat Commun · 2026

basic_science · Level V

Where this comes from

Abstract

CD8<sup>+</sup> T stem cell memory (T<sub>SCM</sub>) cells show clinical promise for cancer immunotherapy, but T<sub>SCM</sub> cell generation in clinical settings requires further optimization. Ponatinib is a tyrosine kinase inhibitor primarily targeting BCR-ABL1 and used for the treatment of chronic myeloid leukemia. Here, we investigate the effect of ponatinib on T cell activation and differentiation. Acting off-target, ponatinib inhibits LCK and PI3K signaling to enhance the transcriptional functions of TCF7 and FOXO1, thereby promoting CD8<sup>+</sup> T<sub>SCM</sub> cell differentiation. Mechanistically, stable and sustained, but not intermittent, inhibition of the LCK and PI3K pathways is essential for CD8<sup>+</sup> T<sub>SCM</sub> cell induction. In mouse tumor models, ponatinib treatment exhibits antitumor efficacy alone and in combination with PD-1 blockade. Furthermore, ponatinib increases chimeric antigen receptor (CAR) T<sub>SCM</sub> cells by reducing CAR T cell exhaustion, resulting in durable antitumor efficacy. Our results thus implicate ponatinib as therapeutic immunomodulator, inducing T<sub>SCM</sub> cells for improved antitumor T cell activity.