Patients with refractory and/or recurrent B cell malignancies have poor prognosis despite complex multimodal therapy. Despite impressive progress, more than 50% of patients treated with CD19-targeting chimeric antigen receptor T cells (CAR19) experience progressive disease. Further, more than 40% patients with progressive large B cell lymphoma (LBCL) experienced reduced or lost expression of CD19 on the tumor cells after CAR19 treatment; low surface CD19 density before treatment was associated with progressive disease. Therefore, novel curative approaches are needed. The investigation attempts to use genetically modified T cells to express a 4th generation lentiviral anti-CD19/22 bi-specific CAR (bi-4SCAR-CD19/22). The CAR molecules enable the T cells to recognize and kill tumor cells through the recognition of a surface antigen, CD19 or CD22, which is expressed at high levels on tumor cells but not at significant levels on normal tissues.~To overcome tumor escape of single target antigen and enhance in vivo CAR-T efficacy, a novel bi-specific CD19/22 CAR-T therapy regimen is developed to include booster and consolidation CAR-T applications to target highly-refractory B cell cancer. The aim is to evaluate safety and long term efficacy of the bi-CAR-T therapy strategy in CD19 and/or CD22 positive cancer patients.
The purpose of this study is to assess the feasibility, safety and efficacy of anti-CD19/22 bi-specific CAR-T cell therapy in patients with CD19 and/or CD22 positive B cell malignancies. Another goal of the study is to learn more about the safety and function of the anti-CD19/22 bi-specific CAR-T cells and their persistency in patients.