mPRPS1-CD19CAR T cells

mPRPS1-CD19CAR T cells are genetically engineered T cells designed to target CD19-expressing B-cell acute lymphoblastic leukemia (B-ALL) cells. These CAR T cells are modified to express a mutant form of phosphoribosyl pyrophosphate synthetase I (mPRPS1), which confers resistance to the chemotherapy agent mercaptopurine (6-MP). This modification aims to enable the concurrent administration of CD19CAR T cell therapy with 6-MP and methotrexate (MTX) maintenance therapy, thereby improving long-term event-free survival in patients with relapsed or refractory pediatric B-ALL. The mPRPS1 engineering does not alter the intrinsic T cell phenotype, such as CD4/CD8 ratio, differentiation state, or expression of activation/exhaustion markers.