RecruitingPhase 1Drug trialPreliminary Safety and Tolerability of CD19x22 CAR T Cells in Adolescent and Adult R/R B-NHL PatientsThis open-label, single arm phase 1 trial aims to determine the safety and tolerability of anti-CD19 and anti-CD22 chimeric antigen receptor-expressing (CAR) T cells (CD19x22 CAR T) in adolescents and adults with relapsed/refractory (R/R) B-cell Non-Hodgkin Lymphoma (B-NHL). This trial will determine the maximum tolerated dose of CD19x22 CAR T cells using a standard 3+3 trial design.