Intrapleural interleukin-2–expressing oncolytic virotherapy enhances acute antitumor effects and T-cell receptor diversity in malignant pleural disease

The mainstay of treatment for patients with malignant pleural disease is fluid drainage and systemic therapy. A tumor-specific oncolytic virus or T-cell–activating interleukin-2 immunotherapy may provide an opportunity for local control. We previously developed a vaccinia virus–expressing interleukin-2, an oncolytic virus that mediated tumor regression in preclinical peritoneal tumor models with expansion of tumor-infiltrating lymphocytes. We evaluated the antitumor efficacy and immune modulatory effects of vaccinia virus–expressing interleukin-2 in malignant pleural disease.