RT Journal Article SR Electronic T1 Tumor regression mediated by oncogene withdrawal or erlotinib stimulates infiltration of inflammatory immune cells in EGFR mutant lung tumors JF Journal for ImmunoTherapy of Cancer JO J Immunother Cancer FD BMJ Publishing Group Ltd SP 172 DO 10.1186/s40425-019-0643-8 VO 7 IS 1 A1 Ayeni, Deborah A1 Miller, Braden A1 Kuhlmann, Alexandra A1 Ho, Ping-Chih A1 Robles-Oteiza, Camila A1 Gaefele, Mmaserame A1 Levy, Stellar A1 de Miguel, Fernando J. A1 Perry, Curtis A1 Guan, Tianxia A1 Krystal, Gerald A1 Lockwood, William A1 Zelterman, Daniel A1 Homer, Robert A1 Liu, Zongzhi A1 Kaech, Susan A1 Politi, Katerina YR 2019 UL http://jitc.bmj.com/content/7/1/172.abstract AB Background Epidermal Growth Factor Receptor (EGFR) tyrosine kinase inhibitors (TKIs) like erlotinib are effective for treating patients with EGFR mutant lung cancer; however, drug resistance inevitably emerges. Approaches to combine immunotherapies and targeted therapies to overcome or delay drug resistance have been hindered by limited knowledge of the effect of erlotinib on tumor-infiltrating immune cells.Methods Using mouse models, we studied the immunological profile of mutant EGFR-driven lung tumors before and after erlotinib treatment.Results We found that erlotinib triggered the recruitment of inflammatory T cells into the lungs and increased maturation of alveolar macrophages. Interestingly, this phenotype could be recapitulated by tumor regression mediated by deprivation of the EGFR oncogene indicating that tumor regression alone was sufficient for these immunostimulatory effects. We also found that further efforts to boost the function and abundance of inflammatory cells, by combining erlotinib treatment with anti-PD-1 and/or a CD40 agonist, did not improve survival in an EGFR-driven mouse model.Conclusions Our findings lay the foundation for understanding the effects of TKIs on the tumor microenvironment and highlight the importance of investigating targeted and immuno-therapy combination strategies to treat EGFR mutant lung cancer.Abbreviations:AMAlveolar MacrophageEGFREpidermal Growth Factor ReceptorGzmbGranzyme BMRIMagnetic Resonance ImagingTH1T helper type 1TKITyrosine kinase inhibitorTMETumor microenvironmentTregRegulatory T cell