Efficacy and safety of chimeric antigen receptor T-cell therapy targeting CD19/CD22 in refractory/relapsed transformed aggressive B-cell lymphoma

Indolent lymphomas, including follicular lymphoma (FL), marginal zone lymphoma, lymphoplasmacytic lymphoma and chronic lymphocytic leukemia/small lymphocytic lymphoma, are characterized by a prolonged waxing and waning of the disease course and relatively long survival in most patients compared with their aggressive lymphoma counterparts. However, indolent lymphomas have the potential to transform into more aggressive lymphomas. Patients with FL have a transformation rate of 2–3% per year [1–3], and the most common histological transformation subtype is diffuse large B-cell lymphoma (DLBCL), and transformation to other histological subtypes, such as Burkitt lymphoma, lymphoblastic lymphoma, acute lymphoblastic leukemia and even Hodgkin lymphoma, is also seen.