# Regionally delivered mesothelin CAR-T with PD-1 blockade

Source: https://onco.cc/ideas/idea-mesothelin-car-t-regional/  
OnCo record `idea-mesothelin-car-t-regional` (Idea). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

Deliver engineered T cells directly into the chest cavity where mesothelioma grows, and give immunotherapy to keep them working.

## Summary

This idea would infuse mesothelin-directed CAR-T cells directly into the pleural cavity of patients with relapsed mesothelioma and add PD-1 blockade to keep the cells working. Mesothelin is expressed on almost all mesotheliomas, the pleural space is accessible, regional delivery avoids on-target lung toxicity, and in preclinical models CAR-T exhaustion is reversible with checkpoint blockade. A phase 1 study at Memorial Sloan Kettering Cancer Center led by Adusumilli combined intrapleural CAR-T with pembrolizumab and produced responses and some long survivors. The next step is a phase 2 with a second-line control and an armoured CAR-T arm; at an early clinical stage, it addresses the bottleneck of cold tumours and the idea of treating the body cavity rather than the bloodstream.

## Fields

- Kind: Idea
- Last checked: 2026-09-07
- Hypothesis: Intrapleural mesothelin CAR-T plus PD-1 blockade achieves median OS beyond 24 months in relapsed mesothelioma, exceeding historical second-line outcomes.
- Rationale: Mesothelin is near-universally expressed; the pleural space is accessible; CAR-T exhaustion is reversible with checkpoint blockade in preclinical models.
- Proposed test: Phase 2 with a contemporaneous control (second-line chemotherapy or nivolumab), OS endpoint; armoured (PD-1 dominant-negative) CAR-T variant as a second arm.
- Maturity: early-clinical

## Sources

- Adusumilli et al., Phase 1 trial of regional mesothelin-targeted CAR T-cell therapy with pembrolizumab in malignant pleural disease (Cancer Discovery 2021): https://doi.org/10.1158/2159-8290.CD-21-0407

## Connected records

- cancers: [Mesothelioma](https://onco.cc/cancers/mesothelioma/)
- technologies: [Armoured, logic-gated & next-gen CARs](https://onco.cc/technologies/armored-car/), [CAR-T cell therapy](https://onco.cc/technologies/car-t/)
- targets: [Mesothelin](https://onco.cc/targets/mesothelin/), [PD-1](https://onco.cc/targets/pd1/)
- institutions: [Memorial Sloan Kettering Cancer Center](https://onco.cc/institutions/mskcc/)
- key papers: [A Phase I Trial of Regional Mesothelin-Targeted CAR T-cell Therapy in Patients with Malignant Pleural Disease, in Combination with the Anti-PD-1 Agent Pembrolizumab](https://onco.cc/key-papers/paper-adusumilli-cancer-discov/), [Mesothelin Immunotherapy for Cancer: Ready for Prime Time?](https://onco.cc/key-papers/paper-mesothelin-mesothelioma-j-clin-oncol-2016/), [Mesothelin-Targeted CARs: Driving T Cells to Solid Tumors](https://onco.cc/key-papers/paper-mesothelin-mesothelioma-cancer-discov-2016/), [Mesothelin: a new target for immunotherapy](https://onco.cc/key-papers/paper-mesothelin-mesothelioma-clin-cancer-res-2004/)
- bottlenecks: [Cold tumours and the immunosuppressive microenvironment](https://onco.cc/bottlenecks/b-tme-immunosuppression/)
- ideas: [Treat the body cavity, not the bloodstream, for surface spread](https://onco.cc/ideas/idea-bio2-intracavitary-immunotherapy/)

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