This is a Phase Ib, multi-center, open-label study to characterize the safety, tolerability, pharmacokinetics, pharmacodynamics and preliminary antitumor activity of MIW815(ADU-S100) in combination with the PD-1 checkpoint inhibitor PDR001. Two different schedules will be explored in two dose escalation groups in accessible cutaneous or subcutaneous lesions, as well as an optional dose confirmation group exploring intratumoral injection of viscerally located lesions.