Five-day schedule of vinzolidine, an oral vinca alkaloid, in a variety of tumors.

This Phase I-II trial evaluated vinzolidine (VZL), a semisynthetic vinblastine derivative administered on a five-day oral schedule every 21 days, with 60% of the total dose on day 1 followed by 10% of the total on each of the following four days. Forty-four patients with advanced malignancies were entered in this study and 34 were evaluable for response. Three patients responded, with complete remissions in patients with adenocarcinoma of the lung (39+ weeks) and adenocarcinoma of the pancreas (20+ weeks) and a minor response in a patient with metastatic carcinoid (6 weeks). Myelosuppression was the dose-limiting toxicity, and was remarkable for its unpredictability among patients and even in the same patient receiving a constant dose of vinzolidine. There was one drug related death associated with myelosuppression. This study was closed because of the erratic myelotoxicity of oral vinzolidine. However, the activity observed with vinzolidine merits future trials, using a parenteral formulation which may have more predictable toxicity.