Phase II trial of the novel sulphonylurea sulofenur in advanced breast cancer.

A total of 18 women with advanced breast cancer were treated with sulofenur [LY186641; N-(5-indanylsulfonyl)-N'-(4-chlorophenyl)-urea], a diarylsulfonylurea that has broad-spectrum activity against a number of murine mammary tumour xenografts. The dosage chosen on the basis of pre-clinical and phase I studies was 700 mg/m2 given orally once daily for 14 days, with treatments being repeated every 3 weeks. There was no response. All patients experienced at least grade 1 anaemia, and two patients developed symptomatic methaemoglobinaemia. Two patients developed grade 4 rises in serum liver-function values along with histological changes consistent with drug-induced toxicity. The mean plasma concentrations of 176 micrograms/ml were lower than the levels required to exert anti-tumour effect in the mouse model.