Phase II Study to Evaluate Safety and Efficacy of CB-103 With Venetoclax in Adolescent and Young Adult Patients With Relapsed/Refractory T-ALL or T-LBL

Inclusion Criteria: * Adolescent (12 to 18 years) and adult (19 to 60 years) participants who have relapsed or refractory T-cell lymphoblastic leukemia (T-ALL) or T-Cell lymphoblastic lymphoma (T-LBL) according to 2017 WHO classification \[29\] and NCCN v1 2021 \[30\]: * Participants must have ≥ 5% blasts in the bone marrow as assessed by morphology on standard bone marrow biopsy and aspirate or less than 5% blasts in the bone marrow in presence of extramedullary relapse, excluding isolated central nervous system (CNS) relapse. However, if an adequate bone marrow sample cannot be obtained, participants may be enrolled if there is unequivocal evidence of leukemia with ≥ 5% blasts in the peripheral blood. * Participants are eligible independently of Notch pathway activation in the leukemic blasts: however, a fresh marrow/blood sample must be obtained before starting the study treatment to classify the participants as being either Notch positive or negative. * Leukemic blasts must express of at least 2 of the following immune phenotyping: CD1a, CD2, CD3, CD4, CD5, CD7, CD8, CD34, TCRαβ, TCRγδ, cyCD3 * Participants have adequate performance status (ECOG ≤2) for participants ≥16 years old, Lansky score \>50 for patients \<16 years old. * Participants must be 12 to 60 years of age inclusive when signing the informed consent. For participants \< 18 years of age, parent or legally authorized representative (LAR) should be willing and able to give informed consent. Non-English spea…