Selective JAK2 pathway inhibition enhances anti-leukemic functionality in CD19 CAR-T cells

Area of Science:

• Immunotherapy
• Molecular Targeted Therapeutics
• Oncology

Background:

• CAR-T cell therapy shows promise for B-cell leukemias.
• JAK inhibitors can reduce CAR-T cell potency by inhibiting T cell activation.
• Existing JAK1/2 inhibitors may limit combined efficacy.

Purpose of the Study:

• To investigate the combinatorial effect of a selective JAK2 inhibitor (CHZ868) with CD19 CAR-T cells.
• To assess the impact of CHZ868 on CAR-T cell function and anti-leukemic activity.
• To explore a novel therapeutic strategy for resistant B-cell leukemias.

Main Methods:

• Utilized CD19 CAR-T cells and a selective type II JAK2 inhibitor (CHZ868) in B-cell tumor models.
• Evaluated anti-leukemic activity, CAR-T cell exhaustion, and survival in mouse models.
• Performed transcriptomic analyses to understand the mechanism of action.

Main Results:

• CHZ868 synergistically enhanced anti-leukemic activity of CD19 CAR-T cells.
• JAK2 inhibition by CHZ868 did not induce CAR-T cell exhaustion and maintained efficacy.
• Significantly extended survival in mouse models with JAK2 inhibitor-resistant leukemia.
• CHZ868 preserved CAR-T cell proliferative capacity while impeding differentiation.

Conclusions:

• Selective JAK2 inhibition with CHZ868 potentiates CAR-T cell therapy.
• This combination offers a viable strategy for treating resistant B-cell leukemias.
• Understanding CHZ868's effect on T cell differentiation is key to optimizing therapy.