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 – PLAT and ENCIT – focus on T-cell therapy.
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.
Who can benefit from the studies?
- PLAT – Children and young adults with relapsed or refractory acute lymphoblastic leukemia (ALL) or other CD19+ or CD22+ acute leukemia who have not responded to standard therapies
- ENCIT-01 – Children and adolescents with recurrent or refractory neuroblastoma who are not likely to survive with current treatments
Meet the Experts
Discover a World Without Childhood Cancer
Dr. Michael Jensen describes immunotherapy treatment for childhood cancer. (5:25)
For more information on pediatric immunotherapy or referral information, call 206-987-2106 or send us an email.
Updated April 2018.
New Cure. New Hope.
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