We Partner 4 Research

All Substudies: - Presence of toxicities due to prior therapy must be stable and recovered to Grade 1 or lower. - Eastern Cooperative Oncology Group (ECOG) performance status score of 0 or 1 - Adequate hematologic and end-organ function. - Individuals of childbearing potential who engage in heterosexual intercourse must agree to use specified method(s) of contraception. Substudy B: - Confirmed diagnosis of chronic lymphocytic leukemia (CLL) based on International Workshop on Chronic Lymphocytic Leukemia (IWCLL) 2018 criteria with histologically confirmed Richter transformation (RT) to a diffuse large B-cell lymphoma (DLBCL) subtype. - Relapsed or refractory disease after 1 line of therapy, defined as at least 1 of the following: - Refractory disease, defined as progressive disease or stable disease as best response to first-line therapy. - Relapsed disease, defined as complete remission to first-line therapy followed by biopsy-proven disease relapse. - At least 1 measurable lesion based on the Lugano Classification. Lesions that have been previously irradiated will be considered measurable only if progression has been documented following completion of radiation therapy. Substudy C: - Histologically confirmed mature B-cell non-Hodgkin lymphoma (NHL) Burkitt lymphoma/leukemia. - Relapsed or refractory disease after first-line chemoimmunotherapy, defined as 1 of the following: - Refractory disease, defined as progressive disease or stable disease as best response to first-line therapy; individuals who are intolerant to first-line therapy are excluded. - Relapsed disease, defined as complete remission to first-line therapy followed by biopsy-proven disease relapse. - At least 1 measurable lesion based on the Lugano Classification. Lesions that have been previously irradiated will be considered measurable only if progression has been documented following completion of radiation therapy.

All Substudies: - Prior CAR therapy or treatment with any anti-CD19 therapy. - HIV-positive patients, unless taking appropriate anti-HIV medications, having an undetectable viral load by quantitative polymerase chain reaction (qPCR) and a CD4 count > 200 cells/uL. - Presence of detectable cerebrospinal fluid malignant cells or brain metastases. - History of autoimmune disease (eg, Crohn's disease, rheumatoid arthritis, systemic lupus). Substudy B: - Diagnosis of RT not of DLBCL subtype (including, but not limited to, Hodgkin lymphoma (HL) and prolymphocytic leukemia). - Prior allogeneic or autologous stem cell transplant < 3 months prior to screening and/or < 4 months prior to planned infusion of brexucabtagene autoleucel. - Presence of active graft-versus-host disease following prior stem cell transplant. Substudy C: - Burkitt-like lymphoma with 11q aberration, high-grade B-cell lymphoma with MYC and BCL2 and/or BCL6 rearrangement, or high-grade B-cell lymphoma not otherwise specified. - Prior allogeneic stem cell transplant < 3 months prior to screening and/or < 4 months prior to planned infusion of brexucabtagene autoleucel. - Presence of active graft-versus-host disease following prior allogeneic stem cell transplant. - Presence of CNS involvement. Individuals with a prior history of CNS involvement are eligible if they show a negative CSF and no involvement by imaging. Substudies A and D have been early terminated by the sponsor. Note: Other protocol defined Inclusion/Exclusion criteria may apply.