Phase I study of the mitomycin C analogue BMS-181174

BMS-181174 is an waminodisulphide derivative of Mitomycin C (MMC) with acti vity against a range of tumour cell lines and xenografts, including MMC-res istant tumours. In a phase I study of 82 patients with confirmed malignancy , we administered EMS-181174 at doses of 0.8-75 mg m(-2) by intravenous inj ection every 28 days. At least three patients were evaluated at each dose l evel, and 174 courses were administered. The pharmacokinetics were dose lin ear at EMS-181174 doses of 11.5-75 mg m(-2) and the drug appeared to underg o wide distribution. The maximum-tolerated dose was 65 mg m(-2) in previous ly treated patients and 75 mg m(-2) in chemotherapy-naive cases. The dose-l imiting toxicity was myelosuppression, particularly thrombocytopenia, which was prolonged and cumulative. Three patients treated at 65-75 mg m(-2) die d suddenly with evidence of pneumonia/pneumonitis, thought to be drug-relat ed. Other toxicities included thrombophlebitis, possible cardiotoxicity (as ymptomatic, reversible decline in left ventricular function) and renal impa irment. The partial response rate was 5% (4 out of 82) overall, and 9% (3 o ut of 32) in patients treated at 65-75 mg m(-2). Responses occurred in trea ted and previously-untreated patients, including cases of colorectal cancer , non-small-cell lung cancer, ovarian cancer and adenocarcinoma of unknown primary site. BMS181174 has anti-cancer activity but, because of its toxici ty, particularly pneumonitis and thrombophlebitis, no phase II studies are planned.