Phase I study of maytansine using a 3-day schedule

Maytansine, a new ansa macrolide antitumor antibiotic, was administered to 60 patients as part of a phase I study. The doses given ranged from 0.01 (starting level) to 0.9 mg/m² for 3 days. The toxic effects encountered consisted principally of nausea, vomiting, diarrhea, and occasionally, stomatitis, and alopecia. Superficial phlebitis was also encountered and occurred when the drug was diluted in a volume of <250 ml. Myelosuppression occurred infrequently; it was almost regularly associated with abnormal liver function tests. Antitumor activity was detected in one patient each with melanoma, breast carcinoma, and head and neck clear cell carcinoma. Further studies are indicated with this compound since it has shown evidence of activity with little or no myelosuppression.