Here, we present the results of a phase 1 study (ClinicalTrials.gov identifier: NCT05333302) evaluating CD19 CAR T cells (BY19) in patients with relapsed or refractory B cell malignancies conducted in the Republic of Belarus, demonstrating both the feasibility of manufacturing and preliminary durable responses across different B cell neoplasms. Here, CD19 is linked to B-cell neoplasm.