Phase I evaluation of prolonged-infusion gemcitabine with fludarabine for relapsed or refractory acute myelogenous leukemia.

PURPOSE The purpose of this study was to determine the maximum tolerated duration of infusion of gemcitabine at 10 mg/m(2)/min in combination with fludarabine at 25 mg/m(2) daily for 5 days in the treatment of relapsed or refractory acute myelogenous leukemia. EXPERIMENTAL DESIGN Eighteen patients with relapsed or refractory acute myelogenous leukemia were enrolled. The median age was 54.5 years (range, 21-80 years). Patients received a 30-min infusion of fludarabine at 25 mg/m(2) daily for 5 days. i.v. gemcitabine was given as a single infusion at 10 mg/m(2)/min with the duration adjusted following a modified continuous reassessment method. RESULTS After 18 patients, the maximum recommended duration of infusion of gemcitabine in combination with fludarabine was selected as a 15-h infusion given at 10 mg/m(2)/min (9,000 mg/m(2)). Severe stomatitis or esophagitis was the most common nonhematological dose-limiting toxicity. Myelosuppression was universal. Febrile neutropenia was common, and 3 of 18 (17%) patients developed bacteremia. Occasional nausea, vomiting, or diarrhea was also reported. There were three complete responses and two partial responses for an overall response rate of 28%. CONCLUSIONS Prolonged-infusion gemcitabine at a fixed dose rate of 10 mg/m(2)/min for 15 h with 25 mg/m(2)/day fludarabine for 5 days is a tolerable induction regimen for relapsed or refractory leukemia. Stomatitis, esophagitis, febrile neutropenia, and myelosuppression should be anticipated; however, this regimen may be beneficial in patients with relapsed or refractory leukemia.