Phase I study of intra-pleural administration of GL-ONC1, an oncolytic vaccinia virus, in patients with malignant pleural effusion.

7559 Background: GL-ONC1 is an attenuated vaccinia virus genetically engineered with the insertion of RUC (luciferase)-GFP, LacZ (beta-galactosidase), and gusA (beta-glucuronidase) genes. We investigated the feasibility, safety, and recommended dose of GL-ONC1 when administered intrapleurally. Methods: Pts with pleural effusion from malignant pleural mesothelioma (MPM), NSCLC, breast cancer, or other solid tumor, and a free pleural space were eligible. Single doses of 1x107, 1x108, 1x109, or 3x109 plaque forming units were administered, and escalation used a 3+3 design. Virus was infused with 500cc Ringer’s Lactate over 1hr through a pleural catheter. Fluorescent-imaging guided, thoracoscopic pleural biopsies were performed 2-9 days later. Blood, sputum, urine, and pleural fluid were analyzed for viral shedding by viral plaque assays (VPA). No chemotherapy or radiation was administered during the course of the study (-14 days to 60 days). Results: 14 pts have been treated: MPM (11), NSCLC (2), breast (1)....