STAT3-IN-18 (compound SPP) is a platinum (IV) complex with an axial ligand derived from sandalwood. STAT3-IN-18 inhibits the JAK2-STAT3 pathway in breast cancer (BC) cells, with anti-proliferative activity. STAT3-IN-18 activates caspase-3 and increases cleaved polyADP-ribose polymerase to induce apoptosis. STAT3-IN-18 promotes maturation and antigen presentation of dendritic cells and demonstrates safety in vivo.