Current Research Studies

Cancer – PLAT-03: A Pilot Feasibility and Safety Study of CD19t T-APC Vaccination Following CAR T-Cell Immunotherapy for CD19+ Leukemia

Condition or Therapy:

Leukemia and lymphoma 


Cancer and Blood Disorders

What is the goal of this study?

PLAT-03 is a phase 1 trial that will test the feasibility and safety of giving a series of 1 to 6 “booster” infusions called T cell antigen-presenting cells (T-APCs). These will be given to children and young adults after they receive their initial T-cell therapy on PLAT-02. The infusions of T-APCs are intended to make the patient’s reprogrammed cancer-fighting T cells last longer.

Learn how CAR T-cell therapy works

Who can join the study?

This study might be a good fit for children or young adults who:

  • Are ages 1 to 26 years old
  • Are enrolled in phase 2 of Seattle Children’s PLAT-02 trial
  • Have been identified as being at risk for losing their reprogrammed T-cells shortly after T-cell therapy
  • After receiving T cells through PLAT-02, have lost their reprogrammed T cells within 6 months

Researchers use many other factors to decide whether a patient can take part in a study (inclusion criteria) or cannot take part (exclusion criteria). The study team at Seattle Children’s can explain what these factors mean for you or your child.

What will happen if my child takes part in this study?

You can read more about the PLAT-03 study at

Who can I contact for more information?

Please email or call us at 206-987-2106 to learn more about the study.

Learn about other PLAT studies at Seattle Children's: 

  • PLAT-02: A Phase 1/2 Feasibility and Safety Study of CD19-CAR T-Cell Immunotherapy for CD19+ Leukemia
  • PLAT-05: A Phase 1 Feasibility and Safety Study of Dual Specificity CD19 and CD22-CAR T-Cell Immunotherapy for CD19+CD22+ Leukemia and Lymphoma
  • PLAT-07: A Phase 1/2 Study of CD22-Specific CAR T Cells for CD22+ Leukemia or Lymphoma

Study Location(s):

Seattle Children's Hospital main campus 

Principal Investigator:

 Dr. Colleen Annesley