A phase I study of vinblastine tryptophan ester.

Vinblastine tryptophan ester (VTrpE) is a new vinca alkaloid derivative that achieves antitumor activity in a large variety of animal models. In this phase I study the drug was given as an i.v. injection over 5 min, once a week or once every 2 weeks. Twenty patients with advanced cancer were entered in this trial. The doses ranged from 2.5 mg/m2 to 35 mg/m2. Myelosuppression is the dose-limiting toxicity, with the risk of leukopenia being more serious than that of thrombocytopenia, but the myelosuppression is always reversible. Neurotoxicity, well documented when other vinca alkaloid derivatives are used, is insignificant. Two cases of disease stabilization have been observed in patients with non-small cell lung cancer. For VTrpE, a dose schedule of 30 mg/m2 per week may be recommended for phase II studies in non-small cell lung cancer.