Pilot study of ONCOS-102 and pembrolizumab for anti-PD1-resistant advanced melanoma

Intratumoral oncolytic virotherapy may overcome anti-PD-(L)1 resistance by triggering pro-inflammatory remodelling of the tumor environment. A pilot study investigated intratumoral ONCOS-102 (oncolytic adenovirus expressing GM-CSF) plus pembrolizumab for anti-PD-1 resistant advanced melanoma. The treatment was well tolerated: most adverse events were mild or moderate in severity. The ORR was 35%. Reduction in size of one or more non-injected lesions were observed in 53% of patients, indicating a systemic effect. In injected tumors, persistent immune-related gene expression and T-cell infiltration was associated with clinical benefit. The authors conclude that further investigation of ONCOS-102 plus PD-1 blockade is warranted.