Advances of platinum-based complexes in chemo-immunotherapy strategies for malignant tumor

Platinum-based complexes, particularly divalent platinum platinum(Ⅱ), Pt(Ⅱ) compounds, have become classic chemotherapy agents for the treatment of malignant tumors. However, their widespread clinical use is limited due to issues such as insufficient stability, the induction of acquired resistance and strong cytotoxicity. Although antibodies that interfere with the interaction between programmed cell death protein 1 (PD-1) and programmed cell death ligand 1 (PD-L1), in combination with platinum-based compounds, have shown significant clinical progress in cancer treatment, their high efficacy is often accompanied by substantial toxicity and immune-related side effects, which limit their long-term use. In contrast, platinum(Ⅳ) Pt(Ⅳ) complexes, with their unique octahedral geometry, have demonstrated promising anticancer potential. By modifying the axial ligands, Pt(Ⅳ)-based complexes not only show higher inertness and improved tumor selectivity, but also enable the targeted release of active ligands in the tumor microenvironment. The mechanism allows Pt(Ⅳ)-based complexes to overcome drug resistance, reduce toxicity and enhance immune system activation, making them a research hotspot in the current cancer field. More importantly, Pt(Ⅳ)-based complexes can exert anticancer effects through multiple pathways including causing DNA damage to trigger apoptosis, autophagy and ferroptosis in tumor cells. This multifaceted action mechanism not only enhances antitumor efficacy but also significantly reduces side effects associated with traditional platinum-based compounds. This review summarizes whole anticancer mechanisms of platinum-based complexes, particularly Pt(Ⅳ) complexes in chemo-immunetherapy combination therapies, discussing their potential in cancer treatment and providing theoretical support for the development of efficient, low-toxicity and highly selective Pt(Ⅳ)-based complexes.