Troxacitabine, a novel dioxolane nucleoside analog, has activity in patients with advanced leukemia

Purpose: To investigate the toxicity profile, activity, and pharmacokinetic s of a novel L-nucleoside analog, troxacitabine (BCH-4556), in patients wit h advanced leukemia. Patients and Methods: patients with refractory or relapsed acute myeloid (A ML) or lymphocytic (ALL) leukemia, myeladysplastic syndromes (MDS), or chro nic myelogenaus leukemia in blastic phase (CML-BP). Troxacitabine was given as an intravenous infusion over 30 minutes daily for 5 days. The starting dose was 0.72 mg/m(2)/d (3.6 mg/m(2)/course), Courses were given every 3 to 4 weeks according to toxicity and antileukemic efficacy. The dose was esca lated by 50% until grade 2 toxicity was observed, and then by 30% to 35% un til the dose-limiting toxicity (DLT) was defined. Results: Forty-two patients (AML: 31 patients; MDS: six patients [five MDS + one CMML]; ALL: four patients; CML-BP: one patient) were treated. Median age was 61 years (range, 23 to 79 years), and 29 patients were males. Stoma titis and hand-foot syndrome were the DLTs. The MTD was defined as 8 mg/m(2 )/d. The pharmacokinetic behavior of troxacitabine is linear over the dose range of 0.72 to 10.0 m/m(2). Approximately 69% of troxacitabine was excret ed as unchanged drug in the urine. Marrow hypoplasia occurred between days 14 and 28 in 73% of AML patients. Three complete remissions and one partial remission were observed in 30 assessable AML patients. One MDS patient ach ieved a hematologic improvement. A patient with CML-BP achieved a return to chronic phase disease. Conclusion: Troxacitabine has a unique metabolic and pharmacokinetic profil e and significant antileukemic activity. DLTs were stomatitis and hand-foot syndrome. Troxacitabine merits further study in hematologic malignancies. (C) 2001 by American Society of Clinical Oncology.