Phase I Study of Anti-CD22 Chimeric Receptor T Cells in Patients With Relapsed/Refractory Hairy Cell Leukemia and Variant

Background: CAR (Chimeric Antigen Receptor) T cell therapy is a type of cancer treatment in which a person s T cells (a type of immune cell) are changed in a laboratory to recognize and attack cancer cells. Researchers want to see if this treatment can help people with hairy cell leukemia (HCL). Objective: To test whether it is safe to give anti-CD22 CAR T cells to people with HCL. Eligibility: Adults ages 18 and older with HCL (classic or variant type) who have already had, are unable to receive, or have refused other standard treatments for their cancer. Design: Participants will be screened with the following: Medical history Physical exam Blood and urine tests Biopsy sample Electrocardiogram Echocardiogram Lung function tests Imaging scans Some screening tests will be repeated during the study. Participants may need to have a catheter placed in a large vein. Participants will have magnetic resonance imaging of the brain. Participants will have a neurologic evaluation and fill out questionnaires. Participants will have leukapheresis. Blood will be removed from the participant. A machine will divide whole blood into red cells, plasma, and lymphocytes. The lymphocytes will be collected. The remaining blood will be returned to the participant. Participants will get infusions of chemotherapy drugs. Participants will get an infusion of the anti-CD22 CAR T cells. They will stay at the hospital for 14 days. Then they will have visits twice a week for 1 month. After treatment, participants will be followed closely for 6 months, and then less frequently for at least 5 years. Then they will have long-term follow-up for 15 years.