RT Journal Article SR Electronic T1 Switchable CAR-T cells mediate remission in metastatic pancreatic ductal adenocarcinoma JF Gut JO Gut FD BMJ Publishing Group Ltd and British Society of Gastroenterology SP 1052 OP 1064 DO 10.1136/gutjnl-2018-316595 VO 68 IS 6 A1 Raj, Deepak A1 Yang, Ming-Hsin A1 Rodgers, David A1 Hampton, Eric N A1 Begum, Julfa A1 Mustafa, Arif A1 Lorizio, Daniela A1 Garces, Irene A1 Propper, David A1 Kench, James G A1 Kocher, H M A1 Young, Travis S A1 Aicher, Alexandra A1 Heeschen, Christopher YR 2019 UL http://gut.bmj.com/content/68/6/1052.abstract AB Objective Pancreatic ductal adenocarcinoma (PDAC) is a disease of unmet medical need. While immunotherapy with chimeric antigen receptor T (CAR-T) cells has shown much promise in haematological malignancies, their efficacy for solid tumours is challenged by the lack of tumour-specific antigens required to avoid on-target, off-tumour effects. Switchable CAR-T cells whereby activity of the CAR-T cell is controlled by dosage of a tumour antigen-specific recombinant Fab-based ‘switch’ to afford a fully tunable response may overcome this translational barrier.Design In this present study, we have used conventional and switchable CAR-T cells to target the antigen HER2, which is upregulated on tumour cells, but also present at low levels on normal human tissue. We used patient-derived xenograft models derived from patients with stage IV PDAC that mimic the most aggressive features of PDAC, including severe liver and lung metastases.Results Switchable CAR-T cells followed by administration of the switch directed against human epidermal growth factor receptor 2 (HER2)-induced complete remission in difficult-to-treat, patient-derived advanced pancreatic tumour models. Switchable HER2 CAR-T cells were as effective as conventional HER2 CAR-T cells in vivo testing a range of different CAR-T cell doses.Conclusion These results suggest that a switchable CAR-T system is efficacious against aggressive and disseminated tumours derived from patients with advanced PDAC while affording the potential safety of a control switch.