A new immune cell-based treatment for glioblastoma, the most aggressive type of brain cancer, has shown promise in shrinking tumors in the short-term, according to two early clinical trials. 

The trials tested the safety and effectiveness of a personalized therapy called chimeric antigen receptor (CAR) T-cell therapy. This involves drawing out and genetically manipulating patients’ immune cells, known as T cells, to more effectively recognize and attack tumors once they’re reintroduced into the body.