Despite a partial decrease in the induction of type I IFNs compared with MSA-2, PtIV-MSA-2 conjugate (I) is highly cytotoxic to Pan02 tumors (IC50 = 20 nM) and could effectively suppress tumor growth through the STING agonism rather than the simple mixture of platinum and MSA-2.109. Here, STING1 is linked to neoplasm.