Sequential Infusion of Anti-CD22 and Anti-CD19 Chimeric Antigen Receptor T Cells for a Pediatric Ph-Like B-ALL Patient That Relapsed After CART-Cell and Haplo-HSCT Therapy: A Case Report and Review of Literature

Pediatric Philadelphia chromosome-like (Ph-like) acute B-lymphoblastic leukemia (B-ALL), a high-risk subset of B-ALL characterized by a gene expression profile similar to that of Ph-positive ALL, has extremely poor outcome after a relapse following autologous chimeric antigen receptor (CAR)-T and haploidentical (haplo) hematopoietic stem cell transplantation(HSCT)therapy. with very limited treatment options. Donor-derived CAR T-cell therapy, the most vital advanced anticancer technology, may be a promising salvage strategy for patients with Ph-like B-ALL. Here, we presented a relapsed and refractory case of a child with Ph-like B-ALL after autologous anti-CD19 CAR T-cell therapy followed by haplo-HSCT. She successfully achieved the fourth complete remission (CR4) and maintained CR for five months after the sequential infusion of donor-derived anti-CD22 and anti-CD19 CAR T cells, with mild CRS side effects and no obvious graft-versus-host disease. A donorderived anti-CD22 and -CD19 CAR T-cell therapy combined with a sequential infusion strategy may provide a promising alternative treatment strategy as effective and safe salvage therapy for children with recurrent and refractory Ph-like B-ALL after autologous CD19-directed CAR T-cell therapy followed by haplo-HSCT.