ideasIdea
Treat the body cavity, not the bloodstream, for surface spread
Intracavitary immunotherapy targets cancer that coats the lining of the abdomen or chest, which drugs given by drip barely reach. Delivering it straight into the cavity gives far higher local doses.
Peritoneal and pleural surface disease has poor drug penetration from the circulation, which is why intraperitoneal chemotherapy and pressurised aerosol delivery persist despite mixed evidence. Regional immunotherapy — intraperitoneal interleukin-2, checkpoint antibodies, T-cell engagers or CAR-T cells — reaches high local concentrations, and intrapleural mesothelin CAR-T has shown feasibility. The unresolved questions are dosing, drainage-related loss and cytokine toxicity.
Hypothesis
Intracavitary administration achieves at least tenfold higher local drug exposure than intravenous dosing at equal systemic exposure, and produces higher rates of cytological clearance of malignant effusion.
Rationale
Pharmacology strongly favours regional delivery for a compartmentalised disease, and cytological clearance provides a fast, objective, inexpensive endpoint. Regional cell therapy has already been shown to be safer than systemic in the pleural space.
What would test it
A pharmacokinetic and pharmacodynamic study comparing intracavitary with intravenous dosing of the same agent, with cytological clearance and paired compartment sampling as endpoints.
Maturity
early clinical
Who has to act
clinic
Cost to try
Medium ($1M to $50M)
Years to first evidence
6
Bottlenecks it attacks
- Cold tumours and the immunosuppressive microenvironment · Most tumours keep the immune system out or asleep, so immunotherapy helps only a minority.
- 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.