Phase II trial of PCNU in advanced malignant melanoma: an Eastern Cooperative Oncology Group pilot study

PCNU, a chloroethylnitrosourea with high alkylating activity, low carbamoylating activity, optimal octanol: water partition coefficient and broad activity in animal systems, was administered to 32 evaluable patients with measurable metastatic melanoma by brief intravenous infusions every six weeks. The initial dose was 75 or 100 mg/m2, with escalation or reduction for toxicity, and a total of 58 evaluable courses were given. Half of the patient population had received no prior chemotherapy. One objective complete response (duration 585 days) and four objective partial responses (durations 55, 169, 405 and 102 days) occurred, the last recorded in a patient previously treated with DTIC. These responses included visceral, nodal and subcutaneous disease. The response rate was 16% with a 95% confidence interval of 5.5 to 33.7%. Thrombocytopenia was dose-limiting and leukopenia was relatively mild. Gastrointestinal toxicity was less severe than expected for a nitrosourea. PCNU has comparable clinical activity to that of other nitrosoureas in patients with advanced melanoma.