Fig. 1. (a) Metallodrugs approved in US and/or EU countries classified by metal centre. Different formulations of the same active ingredient are not included, nor are pharmaceuticals where the metal represents only the counter ion. Imaging/diagnostic agents, food supplements, agents used as anaesthetics and in implants are also excluded. A comprehensive list of the agents included is in Table S1.† Remarkably, the total number of clinically-approved metallodrugs is about half of that for kinase inhibitors, a single class of organic drugs (see https://www.ppu.mrc.ac.uk/list-clinically-approved-kinase-inhibitors). (b) Timeline describing the development of anticancer drugs cisplatin (Pt1), carboplatin (Pt2) and oxaliplatin (Pt3).