Abstract: Objective  To analyze the clinical characteristics and efficacy of chimeric antigen receptors-modified T cells (CAR-T) based therapy in the treatment of patients with refractory/relapsed B-cell tumor. Methods The data of 2 patients with B-cell tumor who developed a secondary tumor after CD19 and CD22 CAR-T therapy were retrospectively analyzed, and the related literature was reviewed. Results One case was diagnosed as follicular lymphoma and had a progression-free survival of 28 months after treatment with CD19 and CD22 CAR-T therapy, followed by secondary adenocarcinoma; the other case was diagnosed as acute B-lymphoblastic leukemia and had a progression-free survival of 14 months after CD19 CAR-T therapy, followed by secondary acute myeloid leukemia. Conclusions A great breakthrough is made in CAR-T therapy for the treatment of B-cell tumor patients. However, the therapy still has long-term adverse reactions in clinical application, such as the secondary tumor, which needs a long-term follow-up and summary in clinical practice.

Key words: CAR-T therapy, B-cell tumor, Secondary tumor, Long-term adverse reactions