Title: Intraperitoneal immunotherapy with T cells stably and transiently expressing anti-EpCAM CAR in xenograft models of peritoneal carcinomatosis
Abstract: // Wei Xia Ang 1, 2, * , Zhendong Li 1, * , Zhixia Chi 1 , Shou-Hui Du 1 , Can Chen 3 , Johan C.K. Tay 1 , Han Chong Toh 4 , John E. Connolly 5 , Xue Hu Xu 6 , Shu Wang 1, 2 1 Department of Biological Sciences, National University of Singapore 117543, Singapore 2 Institute of Bioengineering and Nanotechnology 138669, Singapore 3 Tessa Therapeutics, Pte Ltd., 239351, Singapore 4 Division of Medical Oncology, National Cancer Centre, 169610, Singapore 5 Programme in Translational Immunology, Institute for Molecular and Cell Biology 138648, Singapore 6 Department of Gastrointestinal Surgery, The Third Affiliated Hospital of Guangzhou Medical University, Guangzhou 510150, China * The authors contributed equally to these work Correspondence to: Shu Wang, email: [email protected] Keywords: peritoneal carcinomatosis, EpCAM, chimeric antigen receptor, T lymphocytes, adoptive immunotherapy Received: June 16, 2016 Accepted: January 03, 2017 Published: January 10, 2017 ABSTRACT The epithelial cell adhesion molecule (EpCAM) is overexpressed in a wide variety of tumor types, including peritoneal carcinomatosis (PC) from gastrointestinal and gynecological malignancies. To develop a chimeric antigen receptor T (CART) cell therapy approach to treat patients with end-stage PC, we constructed third generation CARs specific to EpCAM using the 4D5MOC-B single chain variable fragment. CART cells were generated with lentiviral transduction and exhibited specific in vitro killing activity against EpCAM-positive human ovarian and colorectal cancer cells. A single intraperitoneal injection of the CART cells eradicated established ovarian xenografts and resulted in significantly prolonged animal survival. Since EpCAM is also expressed on normal epithelium, anti-EpCAM CART cells were generated by mRNA electroporation that display a controlled cytolytic activity with a limited CAR expression duration. Multiple repeated infusions of these RNA CAR-modified T cells delayed disease progression in immunodeficient mice bearing well-established peritoneal ovarian and colorectal xenografts. Thus, our study demonstrates the effectiveness of using anti-EpCAM CAR-expressing T cells for local treatment of PC in mice. The possibility of using this approach for clinical treatment of EpCAM-positive gastrointestinal and gynecological malignancies warrants further validation.