Targovax ASA announced immune activation data in the first four patients treated with ONCOS-102 followed by the checkpoint inhibitor (CPI) pembrolizumab (KEYTRUDA) in patients with advanced melanoma whose disease has progressed after prior CPI treatment. This is the first time ONCOS-102 has been used therapeutically in melanoma patients, and also the first time the virus has been administered to CPI refractory patients. In this Phase I open label study, patients are scheduled to receive three intra-tumoral ONCOS-102 injections during the first week, and thereafter subsequently re-challenged with the re-challenged with the programmed cell death protein 1(PD-1) blocking CPI KEYTRUDA. As reported in December, the first planned safety review passed without any issues, and the trial was recommended to continue. To date, four patients have been treated with ONCOS-102, and immune activation has been assessed at week 3. Early systemic immune activation in all four patients was indicated by: Increase of several pro-inflammatory cytokines, Increase of the relative level of cytotoxic CD8+ T-cells and Increase of PD-1 expression on CD8+ T-cells. These data indicate that ONCOS-102 may induce both an innate and adaptive immune activation in CPI refractory patients. In addition, increased PD-1 expression on the surface of CD8+ T-cells after ONCOS-102 treatment suggests that the tumors may be susceptible to re-challenge with KEYTRUDA.