Philadelphia chromosome-positive acute lymphoblastic leukemia: a case report

Prognosis of patients with Philadelphia-positive acute lymphoblastic leukemia (Ph-ALL) relapsing after allogeneic hematopoietic stem cell transplantation (HSCT) is extremely poor. Therefore, effective alternative therapeutic measures are urgently needed. Recently, the use of antigen receptor-modified T cells holds great promise for relapsed and refractory ALL treatment. Prior to chimeric antigen receptor T-cell (CAR-T) infusion conditioning chemotherapy is used routinely to establish a favorable in vivo environment for CAR-T expansion, which has mostly involved fludarabine and cyclophosphamide. We report on a patient presented with extreme fatigue and anemia and was diagnosed with relapsed and refractory acute lymphoblastic leukemia (ALL) harbored T315I-BCR-ABL mutation, who had undergone allogeneic HSCT and multiple reinducing chemotherapy, but achieved complete hematologic remission (CHR) with CAR -T infusion as a later salvage treatment. Prior to CAR-T infusion there was no conditioning chemotherapy, but a bone marrow suppression period induced by ponatinib. CAR-T cell infusion was well tolerated and the patient achieved a CHR and maintained it for three months. At present, there is no relevant report on the use of tyrosine kinase inhibitors (TKI) as preconditioning protocols before CAR-T cells infusion. Our case indicated ponatinib not only reduces tumor burden but may also serve as a conditioning regimen for CAR-T therapy in the treatment of relapsed and refractory Ph-ALL.