A phase II trial was conducted in 57 patients with advanced metastatic breast cancer given 2-N-methyl 9-hydroxy-ellipticine (NMHE) as 100 mg/m2 weekly. Evaluation of response, after at least 4 injections, was possible in 46 patients. Two complete regressions (of 3 and 12 months) and 7 regressions of over 50 p. cent were observed, a total regression rate of 19 p. cent. Regression was mainly observed in cutaneous or subcutaneous metastases. No objective regression was noted for pulmonary or hepatic metastases. Bone metastases were not taken in account when assessing response to treatment. Absence of haematological changes must be emphasized. The most frequent side effects were anorexia, nausea +/- vomiting and dryness of mouth. Major toxicity was intravascular haemolysis, observed in 6 of 175 patients receiving NMHE in the Institut Gustave-Roussy, always controlled by symptomatic treatment. This product, of acceptable efficacy in breast cancer treatment, will probably occupy an original place in anti-cancer chemotherapy because of its lack of myelotoxicity.