ideasIdea
Deliver CAR-T cells straight into the fluid around the brain
Cancer spreading along the linings of the brain is almost untreatable. Injecting engineered immune cells directly into the brain fluid, through a small reservoir, reaches it.
Intraventricular delivery of HER2-directed CAR-T cells via an Ommaya reservoir has produced responses in leptomeningeal metastasis in early trials at City of Hope, and intrathecal chemotherapy is long-established. Local delivery avoids the barrier entirely, gives high local cell dose and appears to reduce systemic cytokine toxicity.
Hypothesis
Repeat intraventricular CAR-T dosing produces cerebrospinal fluid tumour cell clearance in at least a third of patients with leptomeningeal metastasis, with median survival better than the current two to four months.
Rationale
The cerebrospinal fluid is a closed, low-volume compartment where a small number of cells produces high effective concentration, and cell products can be re-dosed through an implanted reservoir without repeated surgery.
What would test it
A multi-centre phase 2 in HER2-positive breast cancer leptomeningeal disease with cerebrospinal fluid cytology and ctDNA clearance as primary endpoints, and quality of life measured throughout.
Maturity
early clinical
Who has to act
clinic
Cost to try
Medium ($1M to $50M)
Years to first evidence
5
Bottlenecks it attacks
- The brain: barrier and sanctuary · Most drugs cannot cross into the brain, so brain tumours and brain metastases lag every other site.
- Metastasis is understood least and studied last · Metastasis causes about nine in ten cancer deaths but gets a small fraction of research money and almost no trials of its own.