A phase I clinical study using l-asparaginase-loaded RBCs in the treatment of pancreatic cancer patients, a phase 2 study of l-asparaginase encapsulated in erythrocytes in patients with acute lymphoblastic leukemia and a multicenter trial of erythrocyte-encapsulated thymidine phosphorylase for the treatment of patients with encephalomyopathy have been conducted. Here, ASPG is linked to acute lymphoblastic leukemia.