Rhenium‐Based Complexes and in Vivo Testing: A Brief History

The success of metal‐based anticancer therapeutics in the treatment of cancer is best exemplified by cisplatin. Currently used in 32/78 cancer regimens, metal‐based drugs have a clear role in cancer therapy. Despite this, metal‐based anticancer therapeutics are not without drawbacks, with issues such as toxic side effects and the development of resistance mechanisms. This has led to investigations of other metal‐based drug candidates such as auranofin, a gold‐based drug candidate as well as ruthenium‐based candidates, NAMI‐A, NKP‐1339 and TLD‐1433. All are currently undergoing clinical trials. Another class of complexes under study are rhenium‐based; such complexes have undergone extensive in vitro testing but only nine have been reported to display antitumour in vivo activity, which is a necessary step before entering clinical trials. This review will document, chronologically, the rhenium‐based drug candidates that have undergone in vivo testing and the outlook for such complexes.