Research and Clinical Trials
T-Cell Immunotherapy Overview
Seattle Children’s doctors and researchers are leading efforts to better treat cancer in children, adolescents and young adults by boosting the immune system with immunotherapy. Clinical trials developed at the Ben Towne Center for Childhood Cancer Research focus on chimeric antigen receptor (CAR) T-cell therapy. Open clinical trials include:
- Acute lymphoblastic leukemia and non-Hodgkin lymphoma: Pediatric Leukemia Adoptive Therapy (PLAT)
- Acute myeloid leukemia: HA-1 Therapy
- Brain and central nervous system tumors: BrainChild
- Neuroblastoma: Engineered Neuroblastoma Cellular Immunotherapy (ENCIT)
- Solid tumors: STRIvE
Is T-cell therapy effective?
The clinical trials needed to answer that question are ongoing, but early results are very promising. In April 2017, Seattle Children's published in Blood that:
- 40 of 43 patients achieved complete initial remission during treatment in the phase 1 PLAT-02 clinical trial studying immunotherapy to treat relapsed acute lymphoblastic leukemia (ALL). This is a 93% initial remission rate.
- Of the children who achieved initial remission, about 50% were still in remission 1 year after therapy. Some have now been in remission for more than 3 years.
How does CAR T-cell therapy work?
T cells are white blood cells in the immune system that fight infection. The goal with T-cell immunotherapy is to reprogram a child’s own T cells so they can seek out and destroy cancer cells wherever they are hiding in the body.
The steps in this process are:
- A blood sample is drawn from the child. This sample goes to a special part of Seattle Children’s Research Institute called the Therapeutic Cell Production Core. Lab staff remove the T cells from the sample, purify them and reprogram them. In this case, “reprogram” means to change the T cells by adding recombinant DNA (genetically modify them). Then, the newly programmed T cells are grown to multiply into millions of new cells.
- The changed T cells are put back into the child’s body through an intravenous (IV) infusion.
- The hope is that the changed cells will go to work right away, finding and destroying the cancer cells in the child’s body. The change tells the T cells to make a place on their surface (a receptor) that acts like Velcro. This receptor allows the T cells to recognize and bind to a target on the cancer cells. When they bind, the T cells can attack the cancer cells as if they were fighting an infection.
The receptor that’s made on the T cells is called a chimeric antigen receptor (CAR). T cells that have the receptor may be called CAR T cells.
The change made to the T cells also “tags” the cells so our research team can track them in the body. If doctors want to stop the action of the T cells later, they can do this with the drug cetuximab, which recognizes the tag.
Learn how immunotherapy research at Seattle Children’s is paving the way to become the next great advancement in cancer treatment. Through cellular engineering, we enable the body’s own immune system to heal itself – without the harsh and often lifelong side effects of chemotherapy and radiation.
Who can benefit from the studies?
- BrainChild-01 and -02: Children and young adults who have relapsed or refractory brain or central nervous system (CNS) tumors that express the protein HER2 or EGFR.
- ENCIT-01: Children and adolescents with recurrent or refractory neuroblastoma who are not likely to survive with current treatments.
- HA-1 therapy: Children and young adults with relapsed or refractory acute myeloid leukemia (AML), T-cell ALL or B-cell ALL that does not respond to treatment after a donor stem cell transplant.
- PLAT: studies: Children and young adults with relapsed or refractory CD19+ or CD22+ acute leukemia or lymphoma who have not responded to standard therapies or who have relapsed after other T-cell therapy.
- STRIvE-01: Children and young adults with relapsed or refractory solid tumors that express the protein EGFR.
Meet the Experts
- Katie Albert, MD
- Colleen Annesley, MD
- Marie Bleakley, MD, PhD
- Rebecca Gardner, MD
- Michael Jensen, MD
- Julie Park, MD
- Corinne Summers, MD
- Nicholas Vitanza, MD
Meet the Heroes (video 4:43)
Updated August 2018.