CD19-targeted CAR T cell therapy has transformed the treatment landscape for children and young adults with chemo-refractory or relapsed B cell Acute Lymphoblastic Leukemia (B-ALL). Despite remarkable initial response rates, approximately 50% of pediatric patients experience a subsequent disease relapse. The prognosis for these patients is dismal with a median survival of less than one year from the time of post-CART19 relapse. The primary mechanisms contributing to CART19 failure include CD19-antigen escape and loss of CAR T cell surveillance due to short CART persistence. This study aims to counter each driver of relapse by co-administering two next-generation CAR T cell products: an anti-CD22 CART (CART22-65s), designed to overcome CD19-antigen escape; and a humanized anti-CD19 CART (huCART19), designed to overcome immune-mediated rejection of murine CART19.
This study will evaluate the safety and efficacy of administering two CAR T cell products, huCART19 and CART22-65s, in children with advanced B cell Acute Lymphoblastic Leukemia (B-ALL).