Phase I study of diaziquone.

Twenty-eight patients received diaziquone (AZQ) as a single iv dose ranging from 2 to 27.5 mg/m2 in a phase I study. Myelosuppression was dose-limiting, tended to be cumulative, and was somewhat unpredictable in its occurrence. No pretreatment patient characteristics or chemical abnormalities were found to be consistently related to hematologic toxicity. No objective responses were noted in this study, with most patients having gastrointestinal neoplasms. A single iv injection of 22.5-27.5 mg/m2 of AZQ given every 4-5 weeks would be a suitable initial schedule. Pharmacokinetic studies revealed that the plasma elimination of AZQ was best described by a two-compartment open model with rapid plasma elimination of the parent drug.