Phase I evaluation of gemcitabine, mitoxantrone, and their effect on plasma disposition of fludarabine in patients with relapsed or refractory acute myeloid leukemia

Abstract

Our aim was to estimate the duration of maximum tolerated dose (MTD) duration for gemcitabine given as a continuous infusion in combination with fludarabine and mitoxantrone and to evaluate potential pharmacokinetic (PK) interactions in 17 patients with refractory or relapsed acute myeloid leukaemia (AML). Gemcitabine was administered at 10 mg/m(2)/min for 3-15 h, fludarabine at 25 mg/m(2) daily for days 1-5 and mitoxantrone at 10 mg/m(2) daily on days 1-3. PK studies revealed that fludarabine clearance was not affected by gemcitabine but mean terminal half-life and volume of distribution of fludarabine were slightly increased. The duration of MTD for gemcitabine was 12 h. Our previous in vitro work has demonstrated the binary combination of gemcitabine + fludarabine is most synergistic at a molar ratio around 0.002. However, with MTD dosing this drug ratio is not optimal to produce synergy and future studies using ratiometric dosing are required to confirm these findings.

Phase I study of dose dense induction and consolidation with gemtuzumab ozogamicin and high dose cytarabine in older adults with AML

“…38,39 Phase I studies at our institution using a single prolonged infusion gemcitabine in AML has shown promising results. 40,41 In addition, this study led to the exploration of the biology of AML in older adults at a gene-expression level. Our group at Duke was able to demonstrate that older adults with AML have a higher probability of RAS, TNF, and Src pathway activation compared to their younger counterparts.…”