Multicenter randomized phase 2 study of chemotherapy with or without ONCOS-102 for malignant pleural mesothelioma

ONCOS-102, an oncolytic adenovirus expressing granulocyte-macrophage colony-stimulating factor, can alter the tumor microenvironment to an immunostimulatory state. A randomized phase 2 study in Spain and France evaluated addition of intratumoral ONCOS-102 to pemetrexed and platinum chemotherapy for unresectable malignant pleural mesothelioma (MPM). By day 36, ONCOS-102 was associated with increased T-cell infiltration and immune-related gene expression that was not observed in the control cohort. Among chemotherapy-naïve patients, median overall survival was 20.3 months with ONCOS-102 plus chemotherapy versus 13.5 months with chemotherapy alone (p=0.088),with 30-month OS-rate 34.1% versus 0. No patients discontinued ONCOS-102 dus to adverse events. The authors conclude that ONCO-102 plus chemotherapy was tolerated well bij MPM patients. In injected tumors, ONCOS-102 promoted a proinflammatory environment, which showed association with survival at month 18.