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

This study is testing a new therapy called OC-1 for patients with a rare and aggressive type of leukemia called T-ALL or T-cell lymphoblastic lymphoma (T-LL) that has relapsed (come back) or stopped responding to prior treatments. OC-1 is designed to target a specific protein (CD1a) found on the surface of these cancer cells. **You may be eligible if...** - You are older than 2 years (children and adults are eligible) - Your leukemia or lymphoma cells express a specific marker called CD1a (confirmed by testing) - Your cancer has relapsed or failed to respond to at least two rounds of chemotherapy - You are not pregnant and are using effective contraception if applicable **You may NOT be eligible if...** - You have significant heart, lung, liver, kidney, or brain problems - You had a stem cell transplant within the past 3 months or still need anti-rejection medications - You have uncontrolled epilepsy or severe nervous system disease - You have an active, uncontrolled infection or HIV/active hepatitis - You are pregnant or breastfeeding - You have another uncontrolled cancer Talk to your doctor to see if this trial is right for you.