UCSF Immune Cells That Switch On Only in the Brain Clear Childhood Brain Tumors in Mice
Early research on a deadly pediatric cancer shows promise; human trials could begin as soon as April 2027.
Scientists at the University of California, San Francisco have designed an experimental cell therapy that stays inactive until it reaches the brain, and in mice it eliminated tumors from a deadly childhood cancer. The work, published on 28 October 2026 in *Science Translational Medicine*, is early laboratory research, not a treatment available to patients.
What the team did
The therapy, called B-SYNC CAR-T, modifies a patient's own T cells with a sensor that switches on cancer-fighting activity only when it detects brevican, a protein abundant in the brain. In tests, the cells did not activate in blood or spleen. The team, including Senthilnath Lakshmanachetty, Hideho Okada and Wendell Lim, tested it against diffuse midline glioma, an aggressive pediatric brain cancer that is nearly always fatal within a year.
Results in mice
- Delivered directly into the brain, the cells eliminated tumors in every treated mouse in two models; conventional CAR-T cells did not control them.
- About seven weeks later, the mice rejected re-introduced cancer cells.
- The engineered cells stayed functional for more than 70 days.
Why it matters
Limiting activity to the brain could reduce the risk of the cells attacking healthy tissue elsewhere. The approach also relies on a brain-associated signal rather than a mutation found in only a minority of patients, so it may suit more people.
Caveats and next steps
Mouse results often do not carry over to people, and the number of animals was not reported in the summary reviewed. The researchers say the exact reason the cells last so long remains unclear. Clinical trials at UCSF Health could begin as early as April 2027, comparing intravenous delivery with direct delivery to the brain.
