RT Journal Article SR Electronic T1 Anti-pancreatic tumor efficacy of a Listeria-based, Annexin A2-targeting immunotherapy in combination with anti-PD-1 antibodies JF Journal for ImmunoTherapy of Cancer JO J Immunother Cancer FD BMJ Publishing Group Ltd SP 132 DO 10.1186/s40425-019-0601-5 VO 7 IS 1 A1 Kim, Victoria M. A1 Blair, Alex B. A1 Lauer, Peter A1 Foley, Kelly A1 Che, Xu A1 Soares, Kevin A1 Xia, Tao A1 Muth, Stephen T. A1 Kleponis, Jennifer A1 Armstrong, Todd D. A1 Wolfgang, Christopher L. A1 Jaffee, Elizabeth M. A1 Brockstedt, Dirk A1 Zheng, Lei YR 2019 UL http://jitc.bmj.com/content/7/1/132.abstract AB Background Immune checkpoint inhibitors are not effective for pancreatic ductal adenocarcinoma (PDAC) as single agents. Vaccine therapy may sensitize PDACs to checkpoint inhibitor treatments. Annexin A2 (ANXA2) is a pro-metastasis protein, previously identified as a relevant PDAC antigen that is expressed by a GM-CSF-secreting allogenic whole pancreatic tumor cell vaccine (GVAX) to induce an anti-ANXA2 antibody response in patients with PDAC. We hypothesized that an ANXA2-targeting vaccine approach not only provokes an immune response but also mounts anti-tumor effects.Methods We developed a Listeria-based, ANXA2-targeting cancer immunotherapy (Lm-ANXA2) and investigated its effectiveness within two murine models of PDAC.Results We show that Lm-ANXA2 prolonged the survival in a transplant model of mouse PDACs. More importantly, priming with the Lm-ANXA2 treatment prior to administration of anti-PD-1 antibodies increased cure rates in the implanted PDAC model and resulted in objective tumor responses and prolonged survival in the genetically engineered spontaneous PDAC model. In tumors treated with Lm-ANXA2 followed by anti-PD-1 antibody, the T cells specific to ANXA2 had significantly increased INFγ expression.Conclusions For the first time, a listeria vaccine-based immunotherapy was shown to be able to induce a tumor antigen-specific T cell response within the tumor microenvironment of a “cold” tumor such as PDAC and sensitize the tumor to checkpoint inhibitor therapy. Moreover, this combination immunotherapy led to objective tumor responses and survival benefit in the mice with spontaneously developed PDAC tumors. Therefore, our study supports developing Lm-ANXA2 as a therapeutic agent in combination with anti-PD-1 antibody for PDAC treatment.Victoria M. Kim and Alex B. Blair contributed equally to this work.Abbreviations:ALTalanine aminotransferaseANXA2Annexin A2ASTaspartate aminotransferaseCRS-207mesothelin-expressing Listeria-based immunotherapyCycyclophosphamideGM-CSFgranulocyte-macrophage colony-stimulating factorGVAXGM-CSF-secreting pancreatic tumor whole cell vaccineIACUCInstitutional Animal Care and Use CommitteeIFNinterferonIPintraperitonealKPCKrasLSL.G12D/+; p53R172H/+; PdxCretg/+LADDΔactA ΔinlB live attenuated, double deleted Listeria platform strainLm-ANXA2ANXA2-expressing Listeria-based immunotherapyNCBINational Center for Biotechnology InformationPBSphosphate-buffered salinePD-1programmed death-1PDACpancreatic ductal adenocarcinomaPD-L1programmed death-ligand 1qPCRquantitative real-time RT-PCRTNFtumor necrosis factor