Fresh platinum complexes with promising antitumor activity

Platinum-based anticancer chemotherapy constitutes a cornerstone for the treatment of various solid tumors. However, existing platinum drugs like cisplatin encounter many obstacles such as drug resistance and systemic toxicity in clinical applications. Extensive attempts have been made to minimize the side effects of platinum drugs. This review concentrates on the major development of novel platinum complexes in the last five years, and highlights the complexes with DNA damage mode fundamentally different from that of cisplatin. Diverse platinum complexes are discussed in the text, including analogues of cisplatin or oxaliplatin, monofunctional platinum(II) complexes, polynuclear platinum(II) complexes, trans-platinum(II) complexes, and platinum(IV) complexes. All of these complexes display impressive antitumor activity and some of them show remarkable potentiality to circumvent the resistance to cisplatin. On the basis of these new facts, it can be concluded that structural modifications could substantially modulate the DNA binding mode and DNA damage process, and as a result largely improve the antitumor efficacy of platinum complexes.