The goal of the JCAR017 study was to find a safe and effective treatment for children and adolescents with B-cell acute lymphoblastic leukemia (B-ALL) or B-cell non-Hodgkin lymphoma (B-NHL). The researchers wanted to see if liso-cel could help children and adolescents with B-ALL or B-NHL in whom the disease had returned after other treatments. They wanted to determine how safe the new treatment is and whether it works well.
Liso-cel
Liso-cel is made from a particular type of white blood cells called T cells. Healthy T cells are collected from the child's blood. In the laboratory, a new gene is placed in the T cells. This new gene allows the child's T cells (now called CAR T cells) to bind to a special protein called CD19. The CAR T cells can now recognize and attack leukemia and lymphoma cells. This type of treatment is called immunotherapy with CAR T cells or CAR T cell therapy. After chemotherapy treatment, the CAR T cells are returned to the child by infusion.
Almost half showed a response
Twenty-one children with B-ALL from different European countries participated in the study. Fourteen of them eventually received liso-cel. In eleven children, researchers were able to determine how well the treatment worked. Almost half (45.5%) of them showed a response to the treatment. There were no leukemia cells visible anymore in any of them, but normal blood cells had not (yet) fully recovered.
Liso-cel also caused side effects. The most common side effects were anemia and the so-called “cytokine-release syndrome” (CRS), an overreaction of the immune system. In CRS, substances are released that can cause fever, low blood pressure and breathing problems. CRS is a common side effect of CAR T cell therapy. Other side effects that were seen were deficiencies in platelets and white blood cells. No side effects made it necessary to stop treatment.
Study discontinued
Through this study, much has been learned about the safety and efficacy of liso-cel in children and adolescents with relapsed B-ALL. However, liso-cel does not seem to work better than existing treatments. Therefore, the study was discontinued earlier than planned. As a result, the best dosage of liso-cel could not be determined. Six of the children who received liso-cel are now being followed for long-term effects.
More information:
Clinicaltrials.gov: NCT03743246
EU clinical trials registry: 2018-001246-34