In March 2024, doctors at Mass General Brigham tested a bold variation of CAR‑T therapy on three people with recurrent glioblastoma, one of the deadliest brain cancers known. Instead of relying on standard protocols, they combined an existing CAR‑T approach with targeted antibodies, effectively sharpening the immune system’s aim inside the brain. The treatment was delivered directly into the fluid surrounding the brain and spinal cord, bringing engineered immune cells face‑to‑face with the tumor.
The response stunned them. One patient’s tumor shrank by 18.5% in just two days, then by over 60% within ten weeks. Another showed rapid regression; the third had visible MRI changes within five days. These are early, fragile results from only three people, not a cure. Yet for a cancer long defined by hopelessness, this small trial marks something extraordinary: a first, undeniable glimpse that even glioblastoma may finally have a weakness.
