Phase I and pharmacokinetic (PK) dose-adjusted study of IV vinflunine (VFL) in cancer patients with liver dysfunction (LD): Pharmacokinetic results
2523 Background: VFL is a novel microtubule inhibitor of the vinca alkaloid class that has shown high antitumour activity in several in vivo tumour models and in clinical trials. VFL is mainly eliminated through metabolism and bile excretion. Therefore this trial was designed to determine if LD could increase exposure and toxicity of VFL and require a dose-adjustment. Methods: This trial had a sequential design with the objective of determining the maximal tolerated dose (MTD) and the recommended dose (RD) in three groups of LD based on clinical and biological criteria: mild (PT > 70% and UNL < serum bilirubin = 1.5xUNL), moderate (Child-Pugh A) and severe (Child-Pugh B). VFL and 4-O-deacetylvinflunine (DVFL), its only active metabolite, were quantified in whole blood during cycle 1. PK parameters (AUCinf, Cltot) were estimated using a non-compartmental analysis and were compared using a one-way ANOVA with group factor either between groups or between groups and a control group of 49 patients without LD enrolled in phase I trials). Results: Three VFL doses were investigated: The inter-individual variability (CV) in AUCinf was approximately 30% for all groups. Even if AUCinf increased between mild and moderate groups, no difference was demonstrated between moderate and severe LD groups. All individual values were within the range of control values. Cltot were also similar between groups and the control group. Statistical analysis did not evidence any significant difference between groups. No difference was observed in blood concentrations of DVFL compared to the control group. No relationship between dose limiting toxicity and blood exposure was evidenced. Conclusions: The results showed that vinflunine and DVFL pharmacokinetic parameters do not appear to be affected by the degree of LD. However, the dose of VFL has to be adjusted to the level of LD for safety reasons. [Table: see text] No significant financial relationships to disclose.