BrainChild Bio, a spinout from Seattle Children’s Hospital, has raised $116 million in Series A financing to develop CAR-T cell therapies for rare, deadly childhood brain cancers — tumors that have long defied treatment.

Why childhood brain tumors are so hard

CAR-T therapy — in which a patient’s immune cells are engineered to hunt cancer — has been revolutionary for blood cancers. But it has struggled against solid tumors, and brain tumors are especially forbidding: the blood-brain barrier keeps most therapies out, and pediatric brain cancers like diffuse intrinsic pontine glioma (DIPG) are among the most lethal diagnoses in all of medicine, with survival often measured in months.

What sets BrainChild apart

The company’s core idea is about where the cells go. Instead of infusing engineered T cells into the bloodstream and hoping enough reach the brain, BrainChild uses locoregional delivery — administering CAR-T cells directly into the brain and its fluid spaces. Counterintuitively, this turns the blood-brain barrier into an ally: it helps keep the engineered cells concentrated where the tumor is, and may reduce dangerous body-wide side effects such as cytokine release syndrome. Founder Michael Jensen framed the company’s central bet directly: “The prejudice is that the brain would be intolerant to having cells directly administered” — an assumption BrainChild was built to overturn.

The pipeline

The lead program, BCB-276, is in Phase 2 testing for DIPG, a brainstem tumor that strikes roughly 300 U.S. children a year. It targets a protein called B7-H3 and, notably, requires no chemotherapy conditioning regimen — which means it can be dosed repeatedly (primary completion is expected in 2028). A second program, BCB-214, is in preclinical development for glioblastoma, the deadly adult brain cancer, and could enter human trials next year.

Why it matters

Investors in the round include Seattle Children’s and the Washington Research Foundation’s venture arm. For families facing a diagnosis like DIPG — where standard options are few and outcomes devastating — even early-stage progress carries outsized emotional weight. The important caveat is that these therapies remain in trials: the approach is promising and rationally designed, but pediatric brain cancer has broken many hopeful ideas before, and only rigorous clinical data will show whether locoregional CAR-T can change the odds. Not medical advice.