Phase II evaluation of hexamethylmelamine in advanced breast cancer: a Southwest Oncology Group study.

Ninety-eight patients with metastatic breast cancer, heavily pretreated with other agents, were entered in a phase II trial of hexamethylmelamine (HEX). Patients were randomized to receive HEX alone or combined with prophylactic pyridoxine. There was a 2% response rate in 89 partially or fully evaluable patients. Seven percent of these patients developed neurologic toxicity which occurred in the HEX-alone group only.