Phase I study of L-alanosine using a daily x 3 schedule.

L-Alanosine is an antitumor antibiotic that inhibits adenine synthesis. It showed significant activity in animal tumor systems. Using a daily x 3 dose schedule every 3 weeks, we performed a phase I study to determine toxicity in man. Doses of 8-375 mg/m2/day x 3 were administered to 49 patients in 117 courses. The dose-limiting toxic effect was mucositis. Vomiting, infrequent myelosuppression, fever, headache, malaise, and blood pressure changes were detected at higher dose levels. No antitumor activity was noted. Toxicity with this regimen is acceptable. A phase II study with doses of 250 mg/m2/day x 3 every 3 weeks is feasible.