Pediatric and Young Adult Leukemia Adoptive Therapy (PLAT)-02: A Phase 1/2 Feasibility and Safety Study of CD19-CAR T Cell Immunotherapy for CD19+ Leukemia

Patients with relapsed or refractory leukemia often develop resistance to chemotherapy. For this reason, we are attempting to use T cells obtained directly from the patient, which can be genetically modified to express a chimeric antigen receptor (CAR). The CAR enables the T cell to recognize and kill the leukemic cell through the recognition of CD19, a protein expressed of the surface of the leukemic cell in patients with CD19+ leukemia. This is a phase 1/2 study designed to determine the maximum tolerated dose of the CAR+ T cells as well as to determine the efficacy. The phase 1 cohort is restricted to those patients who have already had an allogeneic hematopoietic cell transplant (HCT). The phase 2 is open to all patients regardless of having a history of HCT.

Upon meeting the eligibility requirements and enrolling on study, subjects will undergo apheresis to obtain the T cells for the generation of the CD19 CAR+ T cells. In patients with a prior history of allogeneic HCT, the T cells obtained are of donor origin. The T cells are isolated from the apheresis product, the CD4 and CD8 T cells are then selected and grown separately, transduced with a lentivirus to express the CD19 CAR as well as a truncated EGFR that has no signaling capacity (noted EGFRt) and expanded in culture over a three week period. During the process of cell generation, subjects will continue to be cared for by their primary oncologist and may undergo additional treatment directed at the leukemia during this time.

After the CAR+ T cells have been generated, the subject undergoes a disease assessment and determination if lymphodepletion is necessary. A variety of lymphodepletion strategies are acceptable and determined on a case-by-case basis. At least 48 hours after the completion of lymphodepletion, the subject will receive and infusion of CAR+ T cells at an approximate 1:1 ratio of CD4 to CD8 CAR+ T cells.

Following treatment with the CAR+ T cells, subjects will be followed intensely for 2 months with serial blood testing and re-evaluation of disease status with bone marrow aspirates. After 2 months, clinical care will be resumed by the patient's primary oncologist, and it is possible that they would receive additional chemotherapy or HCT.

Some subjects will receive cetuximab for ablation of the genetically modified T cells. Criteria to receive cetuximab include acute toxicities that are life-threatening, as well as an ongoing remission with continued B cell aplasia.

Upon completion of the study, subjects will be followed bi-annually for 5 years, and then annually for 10 additional years with either a medical history, physical exam and blood tests or a phone call/questionnaire. This follow-up will help to determine if the subject develops any long-term health problems related to the CAR+ T cells including a new cancer.


Seattle Children's Hospital

Status of enrollment

In progress, not accepting new patients

Ages Eligible for Study

For people ages 1-26

Disease indication


Principal Investigator

Anurag Agrawal, MD


Julie Decaris: [email protected]

Additional study eligibility details can be found at UCSF Clinical Trials.