Open Access

Tuuli Ranki, Timo Joensuu, Elke Jäger, Julia Karbach, Claudia Wahle, Kalevi Kairemo, Tuomo Alanko, Kaarina Partanen, Riku Turkki, Nina Linder, Johan Lundin, Ari Ristimäki, Matti Kankainen, Akseli Hemminki, Charlotta Backman, Kasper Dienel, Mikael von Euler, Elina Haavisto, Tiina Hakonen, Juuso Juhila, Magnus Jaderberg, Petri Priha, Lotta Vassilev, Antti Vuolanto, Sari Pesonen

• Late stage cancer is often associated with reduced immune recognition and a highly immunosuppressive tumor microenvironment. The presence of tumor infiltrating lymphocytes (TILs) and specific gene-signatures prior to treatment are linked to good prognosis, while the opposite is true for extensive immunosuppression. The use of adenoviruses as cancer vaccines is a form of active immunotherapy to initialise a tumor-specific immune response that targets the patient’s unique tumor antigen repertoire. We report a case of a 68-year-old male with asbestos-related malignant pleural mesothelioma who was treated in a Phase I study with a granulocyte-macrophage colony‑stimulating factor (GM-CSF)-expressing oncolytic adenovirus, Ad5/3-D24-GMCSF (ONCOS-102). The treatment resulted in prominent infiltration of CD8C lymphocytes to tumor, marked induction of systemic antitumor CD8C T-cells and induction of Th1- type polarization in the tumor. These results indicate that ONCOS-102 treatment sensitizes tumors to other immunotherapies by inducing a T-cell positive phenotype to an initially T-cell negative tumor.