Phase I trial of pentamethylmelamine.

Pentamethylmelamine, an analog of hexamethylmelamine developed for iv use, was administered to 42 patients in a phase I clinical trial. The dose ranged from 0.080 to 2.50 g/m2/day x 5 and was repeated approximately every 3 weeks. The dose-limiting toxic effects included moderate to severe nausea, vomiting, and central nervous system (CNS) toxicity. Myelosuppression was mild and was not dose-limiting. Antineoplastic activity was observed in four patients. Due to unacceptable gastrointestinal and CNS toxic effects from pentamethylmelamine at the active dose levels, we do not recommend disease-specific phase II trials.