Seattle Children’s hospital in the US has started a Phase I chimeric antigen receptor (CAR) T-cell immunotherapy trial (PLAT-05) in children and young adults with relapsed or refractory CD19 and CD22 positive acute lymphoblastic leukaemia (ALL).
The new investigational CAR T cell therapy simultaneously targets the CD19 and CD22 proteins, and is expected to lower the relapse rate by 50%.
PLAT-05 is based on the previous CAR T-cell immunotherapy trials such as the ongoing PLAT-02 trial, when 93% of relapsed or refractory ALL subjects are reported to have experienced complete initial remission.
As 50% of these patients relapsed, the latest trial aims to improve the therapy to deliver long-term remission for all participants by preventing the escape of cancer from the CAR T cells.
For the PLAT-05 trial, researchers intend to reprogramme CAR T cells to identify and kill the cancer by targeting both the CD19 and CD22 proteins. This will ensure detection of the CD22 protein, even when the cancer evolves to not express CD19.
The trial is set to enrol approximately 20 patients over the next 18 months.
Seattle Children’s researchers are currently working towards the development of CAR T-cell trials to target solid tumours such as those in the brain and sarcomas.
PLAT-05 lead investigator and Seattle Children’s oncologist Dr Rebecca Gardner said: "We believe that T-cell immunotherapy holds tremendous potential to combat leukaemia and several other types of paediatric cancer.
"Leukaemia is just the tip of the iceberg, and we hope to develop a therapy that can be given to patients as a first line of defence, greatly reducing the side-effects of cancer treatment."