Summary Oxaliplatin (trans-/-diaminocyclohexane oxalatoplatinum; L-OHP) is a new platinum derivative for the treatment of advanced colorectal cancer. Preclinical data have shown that oxaliplatin is active in a wide range of human and murine tumour cell lines, and has been found to be non-cross-resistant with cisplatin in various cisplatin-resistant cell lines and tumours. Oxaliplatin in combination with 5-fluorouracil (5-FU) leads to synergistic antiproliferative activity both in vivo and in vitro. Clinical data have shown that oxaliplatin is active and well tolerated both as monotherapy and in combination with 5-FU/folinic acid in first-or second-line treatment of patients with metastatic colorectal cancer. Oxaliplatin has a very good safety profile, and studies have confirmed that peripheral sensory neuropathy is related to the cumulative dose of oxaliplatin administered and that this neuropathy is generally reversible after discontinuation of treatment. High response rates and prolonged survival have been achieved in metastatic colorectal cancer patients, even after 5-FU failure.Keywords: advanced colorectal cancer; first-line treatment; 5-fluorouracil/folinic acid; oxaliplatin; second-line treatment; synergistic antiproliferative activity Oxaliplatin (trans-/-diaminocyclohexane oxalatoplatinum; L-OHP) is a new platinum derivative in which oxalate is the hydrolysable ligand and diaminocyclohexane (DACH) the carrier ( Figure 1). The drug is the first clinically available platinum derivative that has been approved in France for the treatment of advanced colorectal cancer.Preclinical data have shown that oxaliplatin is active in a wide range of human and murine tumour cell lines (Silvestro et al, 1990). The National Cancer Institute's Anticancer Drug Screening Programme has shown oxaliplatin to have a very different profile from that of cisplatin when tested on colon cell lines with no crossresistance with cisplatin in most cell lines (Rixe et al, 1996). DNA adducts of oxaliplatin are not recognized by the DNA mismatch repair proteins. The combination of oxaliplatin with other drugs, such as 5-fluorouracil (5-FU) and CPT-I 1, can lead to synergistic antiproliferative activity in vivo and in vitro (Raymond et al, 1996.Five phase I studies have been carried out, involving 122 patients (Mathe et al, 1986;Caussanel et al, 1990;Extra et al, 1990). From these studies, it was clear that haematological toxicity was minimal, with no nephrotoxicity, ototoxicity or alopecia; the doselimiting toxicity was a peripheral sensory neuropathy that was related to the cumulative dose of oxaliplatin administered, and was generally reversible after treatment discontinuation. However, the toxicity profile of oxaliplatin will be discussed in more detail in the following paper. The maximal tolerated dose was 200 mg m-2, and the recommended dose for treating these patients in phase II studies was 130 mg m-2 every 3 weeks.Clinical data have shown that oxaliplatin is active and well tolerated, both as monotherapy and in combination with 5-...