The purpose of this first-in-human (FIH) study of BLZ945 given as a single agent or in combination with PDR001 is to characterize the safety, tolerability, pharmacokinetics (PK), pharmacodynamics, and anti-tumor activity of BLZ945, administered orally, as a single agent or in combination with PDR001, administered intravenously (i.v.) in adult patients with advanced solid tumors.