Abstract 2213: Comparison of infusion devices for hepatic artery delivery of CAR-T
Authors: Darpolor Josephine K. , Cunetta Marissa , Lima Matthew , Gardell Jillian , Point Gary , Liu Zhi , Espat N J. , Guha Prajna , Katz Steven 
Published: July 2016

We previously tested the efficacy of chimeric antigen receptor T cell (CAR-T) treatment via hepatic artery infusion in a phase I clinical trial. Though these results were promising, our current protocol for hepatic immunotherapy for metastasis (HITM) includes transcatheter arterial embolization in order to reduce off-target toxicity from CAR-T delivery to gastric, enteric, or pancreatic tissues. Surefire Infusion System devices employ a soft fabric one way valve that prevents back-flow during hepatic artery infusion and generates a pressure gradient, which is clinically shown to increase delivery of therapeutic agents into tumor. We performed in vitro and in vivo testing in preparation for a phase Ib trial to ensure that the SIS does not adversely affect CAR-T performance. Viability, phenotype and activation status of CAR-T with no catheter (NC) and following passage through a standard microcatheter (STD), Surefire Infusion System (SIS), or Surefire Precision (SP) infusion system were tested via flow cytometry. CAR-T viability was preserved as measured by Zombie NIR. We did not detect a significant phenotype shift when examining CD4, CD8, CD25, and CD69. A CFSE assay and an LDH were done to track proliferation and measure the cytotoxicity of the CAR-T when stimulated by tumor. NC CAR-T had significantly more proliferation than each of the catheter groups. Specific Lysis was not significantly different between the NC, STD, SIS, and SP groups. We also performed in vivo testing in mice with intraperitoneal (IP) tumor with IP NC or SIS CAR-T. By Day 10, there was significantly less tumor present in the NC (5.7- fold reduction, p = 0.02) and the SIS (44- fold reduction, p = 0.04) groups than in the tumor only control group. The SIS CAR-T group and the NC CAR-T group were not significantly different (p = 0.38). The SIS and SP devices did not adversely impact CAR-T viability, phenotype, or performance implying that these catheters could be interchangeably used for more efficient and targeted CAR-T dose delivery.

In Vitro Experimental Data ExperimentNC (Control)STD (Control)SISPSViability (Zombie NIR)6%7.9% p = 0.7 vs NC7.4% p = 0.9 vs. STD9.9% p = 0.7 vs STDPhenotype (CD3+CD4+)33.1%30.6% p = 0.9 vs NC33.3% p = 0.9 vs STD21.3% p = 0.8 vs STDPhenotype (CD3+CD8+)68.8%69.5% p = 0.9 vs NC69.1% p = 0.9 vs STD66.7% p = 0.7 vs STDActivation (CD69+)34.93%32.3% p = 0.9 vs NC33% p = 0.9 vs STD25.6% p = 0.7 vs STDTreg (CD25+)35.2%36.2% p = 0.9 vs NC36.8% p = 0.6 vs STD40.5% p = 0.6 vs STDProliferation (CFSE)41.7%26.7% p = 0.005 vs NC27.3% p = 0.8 vs STD24.2% p = 0.4 vs STDCytotoxicity (LDH Assay)51.2%42.1% p = 0.1 vs NC44% p = 0.7 vs STD41.1% p = 0.9 vs STD

Citation Format: Josephine K. Darpolor, Marissa Cunetta, Matthew Lima, Jillian Gardell, Gary Point, Zhi Liu, N J. Espat, Prajna Guha, Steven Katz. Comparison of infusion devices for hepatic artery delivery of CAR-T. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 2213.