Safety and Efficacy of OC-1 Therapy in Patients With R/R T-ALL/LL

Inclusion Criteria 1. Children older than 2 years or adults, male and female in both groups. 2. Patients CD1a antigen blast expression ≥20% at inclusion, either immunophenotypically (flow cytometry) or histologically confirmed. 3. R/R CD1a-positive T-ALL/LL patients defined as: * Failure to achieve morphological complete remission (\> 5% bone marrow blasts) or persistence of extramedullary disease after at least two cycles of chemotherapy. * First or subsequent relapse, including morphologic or MRD-detectable (≥1x10-4 ) bone marrow and/or extramedullary relapses after at least one standard frontline therapy. * Relapse after allogeneic haematopoietic stem cell transplantation (allo-HSCT). * Primary refractoriness, defined as either morphologic persistence or detectable MRD (≥1x10-4 ) after at least two cycles of chemotherapy, making the patient not candidate for allo-HSCT. 4. Patient without reproductive capacity or else, commitment to the use of a highly effective method of contraception during the study. Exclusion Criteria: 1. Limiting organ dysfunction, such as uncontrolled cardiac (e.g., depressed left ventricular ejection fraction (LVEF), \<45%), pulmonary, liver, renal or CNS dysfunction. 2. Allo-HSCT within a time frame \<3 months, or requiring continued immunosuppressive treatment for graft versus host disease (GvHD). 3. Uncontrolled epilepsy or underlying central nervous system (CNS) severe disease. 4. Active bacterial, fungal or viral infection not controlled by adequate treatment. 5. Known HIV, active hepatitis B (HBV), or hepatitis C virus (HCV) infection. 6. Women who are pregnant (urine/blood pregnancy test positive) or lactating. 7. Severe illness or medical condition, which would not permit the patient to be managed according to the protocol. 8. Suffering from a serious autoimmune disease or immunodeficiency disease. 9. The patient participated in other experimental drug clinical trial within 6 weeks prior to OC-1 infusion. 10. Other non-controlled concomitant neoplasms.