A phase 1 trial involving 12 children with relapsed neuroblastoma - a hard-to-treat pediatric cancer - shows that anticancer CAR T cells displayed signs of efficacy against these tumors while avoiding damage to nerve tissue.
The results suggest that CAR T cells should be further evaluated as treatments for neuroblastoma and other solid tumors, which have typically been difficult to target with T cell therapies.
CAR T cells are immune cells from patients that have been engineered to hunt down cancer cells, and have shown great promise against blood cancers such as leukemia.
However, it has been much more difficult to use CAR T cells against solid tumors, which are harder for the cells to penetrate. Here, Karin Straathof and colleagues performed a phase 1 trial to study the safety and performance of CAR T cells against neuroblastoma.
They created CAR T cells that target the GD2 protein, which is common on neuroblastoma tumors, and administered the cells to 12 pediatric patients who had failed to respond to standard chemotherapies.
None of the children showed measurable drops in the size of their tumors after one month, according to standard X-ray criteria, and some experienced immune-related side effects.
However, three patients who also received two conditioning drugs showed some signs of antitumor immunity, and did not display any signs of damage to healthy nerve tissue bearing GD2. Straathof et al. note that further modifications to the CAR T cells will be necessary to boost their persistence within tumors, given the transient nature of the observed antitumor responses.
Straathof, K., et al. (2020) Antitumor activity without on-target off-tumor toxicity of GD2–chimeric antigen receptor T cells in patients with neuroblastoma. Science Translational Medicine. doi.org/10.1126/scitranslmed.abd6169.