Children's National Health System today announced the opening of a unique chimeric antigen receptor (CAR) T-cell immunotherapy trial for pediatric patients with relapsed positive acute lymphoblastic leukemia (ALL). The PLAT-05 trial will focus on targeting the CD19 and CD22 proteins simultaneously found in leukemia cancer cells. Through the PLAT-05 trial, Children's National researchers will ultimately be able to reduce the rate of relapse following CAR T therapy by almost 50%.

"Being able to participate in another trial that is strengthening this unique pediatric cancer therapy consortium is extremely exciting," said Catherine Bollard, M.B.Ch.B, M.D., director of the Center for Cancer and Immunology Research at the Children's Research Institute.

Children's National is now the second hospital in the country to offer the PLAT-05 trial after it first launched at Seattle Children's. The trial was developed based on what researchers at Seattle Children's Research Institute learned from their PLAT-02 CAR T-cell therapy trial, which targets CD19 protein on cancer cells.

Researchers learned that following CAR T-cell therapy, some patients' leukemia returned and had no longer exhibited the CD19 protein. Instead, the CD22 protein had manifested and the CAR T-cells were unable to recognize and destroy the cancerous cells.

With the PLAT-05 trial, Children's National researchers will be able to reprogram CAR T-cells to detect and destroy leukemia cells by targeting both the CD19 and CD22 proteins upfront. If the cancer evolves to no longer express CD19, the CAR T-cells can still attack the cancer through the identification of the CD22 protein.  

"We're excited to bring CD19 and CD22 CAR T-cell therapy to Children's National for the treatment of pediatric patients with relapsed /refractory acute lymphoblastic leukemia," said Dr. Bollard. "We hope the PLAT-05 trial leads to increased remission rates for our patients in our effort to make them cancer-free for life."

Children's National will leverage their participation in the Consortium for Pediatric Cellular Immunotherapy, a National Institute of Health's U01 funded grant, to advance novel cellular therapies and facilitate the implementation of PLAT-05.

Children's National and Seattle Children's are both CureWorks sites. CureWorks serves as an international collaborative of leading academic children's hospitals determined to accelerate the development of immunotherapy treatments for childhood cancer.

"We are thrilled that children on the East Coast will now have access to PLAT-05 at Children's National, allowing them to participate in the groundbreaking CAR T-cell trial closer to home," said Dr. Mike Jensen, executive director of CureWorks and director of the Ben Towne Center for Childhood Cancer Research at Seattle Children's Research Institute. "Extending the reach of this clinical trial not only allows patients to be treated in their own community, but it also helps to accelerate our ability to ultimately develop a treatment that enables all kids with cancer to grow up and realize their full potential."

The PLAT-05 trial will be open to children and young adults between the ages of 1 to 26-years-old who have experienced relapsed or refractory pre-B acute lymphoblastic leukemia (ALL) or other CD19 or CD22-positive acute leukemia or CD19 non-Hodgkin lymphoma.