Chimeric Antigen Receptor T Cell Therapy Redirected to CD4 (CD4CAR)as a Second Line Treatment for Chronic Myelomonocytic Leukemia, CMML.

This study tests a cutting-edge cell therapy called CD4 CAR T-cell therapy for people with chronic myelomonocytic leukemia (CMML) — a rare blood cancer — whose disease has returned or not responded to standard first-line treatment. This therapy uses the patient's own immune cells, re-engineered to target and destroy cancer cells. **You may be eligible if...** - You are 18 or older - You have CMML that has come back or didn't respond to first-line treatment - Your cancer cells test positive for a protein called CD4 - Your kidney, liver, and heart function are adequate - You do not need supplemental oxygen at rest **You may NOT be eligible if...** - You have active uncontrolled infection - You have had a prior stem cell transplant within a certain timeframe - You have serious heart, liver, or lung problems - You are pregnant or breastfeeding Talk to your doctor to see if this trial is right for you.