Master protocol: The primary objective of this study is to evaluate the efficacy of brexucabtagene autoleucel in four rare B-cell malignancies. This study will use a basket study design with separate, indication-specific substudies, to investigate relapsed/refractory Waldenstrom macroglobulinemia (r/r WM), relapsed/refractory Richter transformation (r/r RT), relapsed/refractory Burkitt lymphoma (r/r BL), and relapsed/refractory hairy cell leukemia (r/r HCL).~After completing the treatment period, all participants will be followed in the post-treatment follow-up period. Thereafter, participants will transition to a separate long-term follow-up study (KT-US-982-5968) to continue follow-up out to 15 years.
Master protocol: The goal of this master clinical study is to test how well the study drug, brexucabtagene autoleucel, works in participants with rare B-cell malignancies: relapsed/refractory Waldenstrom macroglobulinemia (r/r WM) (Substudy A), relapsed/refractory Richter transformation (r/r RT) (Substudy B), relapsed/refractory Burkitt lymphoma (r/r BL) (Substudy C), and relapsed/refractory hairy cell leukemia (r/r HCL) (Substudy D).