A Study of CTD402 in T-ALL/LBL Patients

Key Inclusion Criteria: 1. Male or female, ≥ 1 year of age. 2. Participants with body weight ≥ 40 kilogram. 3. A) Relapsed or refractory T-ALL/LBL or MRD positive defined as one of the following: * Relapsed or refractory disease after two or more lines of systemic therapy; * The first relapse occurs within 12 months after first remission; * Relapse after allogeneic HSCT and must be ≥100 days from HSCT prior to screening period. B) Minimal Residual Disease (MRD) positive T-ALL/LBL is defined as evidence of MRD, defined as \< 5% blasts in bone marrow but ≥ 1 cancer cell in 1,000 cells determined by NGS ClonoSEQ® and/or other regionally acceptable methodologies (e.g., EuroMRD guidelines). 4. The presence of bone marrow lymphoblasts is ≥ 5% as determined by morphologic evaluation or evidence of extramedullary disease at screening. 5. Adequate organ function 6. ECOG of 2 or less or Karnofsky PS ≥ 60 (for participants age ≥ 16) or Lansky PS ≥ 60 (for participants \< 16) at screening. Key Exclusion Criteria: 1. Participants with concomitant genetic syndromes associated with bone marrow failure states or any other known bone marrow failure syndrome. 2. Active central nervous system (CNS) involvement 3. Participants with following cardiac conditions will be excluded: 1. History of heart failure New York Heart Association (NYHA) class III or IV; 2. History of myocardial infarction, cardiovascular angioplasty or stenting, unstable angina, or other serious heart diseases within 12 months of enrollment. 4. Primary immune deficiency. 5. Presence of uncontrolled infections. 6. Known history of infection with the human immunodeficiency virus (HIV); hepatitis C virus and syphilis. 7. Active or latent hepatitis B virus infection 8. Epstein-Barr virus (EBV), Cytomegalovirus (CMV) DNA or IgM positive at screening.