Development of next-generation CAR-T cells for enhanced efficacy and reduced toxicity in T-cell acute lymphoblastic leukaemia (T-ALL) (360G-Wellcome-344116_Z_26_Z)

Background: T-cell acute lymphoblastic leukaemia (T-ALL) has dismal outcomes in relapsed/refractory disease. Whilst CAR-T therapy revolutionised B-ALL treatment, translating this to T-ALL is challenging. Targeting pan-T antigens causes fratricide during manufacture and life-threatening T-cell aplasia. Anti-CD7 CAR-T trials show 80-100% initial responses but frequent antigen- negative relapses, serving merely as bridge-to-transplant with ~20% mortality. I have focused on T-lymphoblast restricted antigens to overcome these challenges, demonstrating CD21 expression on ~50%of T-ALL but less than 10% normal T cells. However, these targets face limitations including heterogeneous expression and potential for antigen-negative relapse. Aims: I will develop next-generation CAR-T therapies through three approaches: discovering novel T-lymphoblast-restricted antigens via proteomics; engineering CAR-T cells co-targeting multiple antigens to maximise patient coverage and prevent escape; and exploring asparaginase combination, exploiting T-ALL's asparagine synthetase deficiency whilst sparing normal T-cells. Methods: Cell-surface capture proteomics on primary T-ALL samples will identify novel targets. Multi-antigen CAR-T cells will be developed using co-transduction approaches and tested against engineered lines and primary samples. Asparaginase combinations will be characterised in vitro and validated using xenograft models. Impact: This research will establish personalised CAR-T therapy pathways, transforming treatment from bridge-to- transplant into standalone curative therapy, potentially revolutionising outcomes for this neglected disease.