Effect of ethnicity on vinorelbine pharmacokinetics: a population pharmacokinetics analysis.

BACKGROUND: Pharmacokinetics of vinorelbine is mainly known from studies conducted in European patients. Interethnic differences in drug disposition may, however, induce interethnic variation in drug exposure. This paper aimed to evaluate the effect of ethnicity on the bioavailability and clearance of oral and intravenous vinorelbine. METHODS: Oral and intravenous vinorelbine pharmacokinetics data in Asian patients were pooled from two-phase II studies of patients with non-small-cell lung cancer or advanced breast cancer in China. Blood vinorelbine and its active metabolite, 4'-O-deacetylvinorelbine, were quantified using liquid chromatography-tandem mass spectrometry. Bayesian pharmacokinetic parameters were calculated and vinorelbine monotherapy results (intravenous 25 mg/m2; oral 60 mg/m2) of the Asian data set were compared to a reference European data set (intravenous 30 mg/m2; oral 80 mg/m2). Subsequently, a population pharmacokinetics analysis was conducted in a combined cohort (Asian data set + historical vinorelbine pharmacokinetics database) to investigate for a potential effect of ethnicity. RESULTS: Pharmacokinetics data from the Asian data set (oral: n = 47; intravenous: n = 34) was compared to the European reference data set (oral: n = 48; intravenous: n = 48). Mean apparent clearance of oral vinorelbine and mean absolute clearance of intravenous vinorelbine was comparable between the Asian and reference European data set. A population pharmacokinetic analysis (oral: n = 222; intravenous: n = 111) demonstrated no influence of ethnicity on oral and intravenous vinorelbine bioavailability and clearance. CONCLUSION: Vinorelbine pharmacokinetics were found to be comparable between Asian and European patients. No relevant influence of ethnicity on vinorelbine bioavailability and clearance for oral and intravenous routes of administration was observed.

Better characterization of vinflunine pharmacokinetics variability and exposure/toxicity relationship to improve its use: Analyses from 18 trials.

AIMS: Vinflunine is a novel tubulin-targeted inhibitor indicated as a single agent for the treatment of bladder cancers after failure of prior platinum-based therapy. Its pharmacokinetics (PK) and pharmacodynamics (PD) have been independently characterized through several phase I and phase II studies. However, no global pharmacometric analysis had been conducted as yet. METHODS: Vinflunine concentrations and safety data from 18 phase I and phase II studies were used to conduct population PK and PK/PD analysis, using Nonmem. A four-compartment model was used to describe vinflunine PK and several covariates were tested to explain interindividual variability. In terms of PK/PD relationship, a semiphysiological population PK/PD model was applied to describe time course of absolute neutrophil counts (ANC) after vinflunine administration and logistic regression models were used to test the relationship between vinflunine exposure and toxicities. RESULTS: Vinflunine clearance is explained by creatinine clearance, body surface area and combination with PEGylated doxorubicin, leading to a decrease from 28.2 to 25.3% of the interindividual variability. When vinflunine dose is decreased, simulations of ANC time course (via a semiphysiological model) after vinflunine administration show a risk of neutropenia grade 3-4 at cycle 2 always lower than when dose is delayed. As an example, for moderate renal impaired patients, the risk is 42.1% when vinflunine is dosed at 320 mg m-2 once every 4 weeks vs. 23.3% for 280 mg m-2 once every 3 weeks. CONCLUSIONS: We propose for the first time a global comprehensive clinical pharmacological analysis for intravenous vinflunine that may help drive dose adjustment.

F14512, a polyamine-vectorized inhibitor of topoisomerase II, exhibits a marked anti-tumor activity in ovarian cancer.

Epithelial ovarian cancer is the fourth cause of death among cancer-bearing women and frequently associated with carboplatin resistance, underlining the need for more efficient and targeted therapies. F14512 is an epipodophylotoxin-core linked to a spermine chain which enters cells via the polyamine transport system (PTS). Here, we investigate this novel concept of vectorization in ovarian cancer. We compared the effects of etoposide and F14512 on a panel of five carboplatin-sensitive or resistant ovarian cancer models. We assessed the incorporation of F17073, a spermine-linked fluorescent probe, in these cells and in 18 clinical samples. We then showed that F14512 exhibits a high anti-proliferative and pro-apoptotic activity, particularly in cells with high levels of F17073 incorporation. Consistently, F14512 significantly inhibited tumor growth compared to etoposide, in a cisplatin-resistant A2780R subcutaneous model, at a dose of 1.25 mg/kg. In addition, ex vivo analysis indicated that 15 out of 18 patients presented a higher F17073 incorporation into tumor cells compared to normal cells. Overall, our data suggest that F14512, a targeted drug with a potent anti-tumor efficacy, constitutes a potential new therapy for highly PTS-positive and platinum-resistant ovarian cancer-bearing patients.

A simple and sensitive high-performance liquid chromatographic method for the determination of vinflunine and 4-O-deacetylvinflunine from human blood.

Vinflunine (VFL) is the first bifluorinated tubulin-targeted agent obtained through a semi synthetic process using superacidic chemistry. Pharmacologic models evidenced a high degree of activity from several cancer lines. The intravenous formulation of VFL (Javlor, Pierre Fabre Medicament, Boulogne, France) is registered for bladder cancer and is undergoing Phase III trials for nonsmall cell lung and breast cancer. To support most of the pharmacokinetic studies in humans, a sensitive high-performance liquid chromatography bioanalytical method coupled with ultraviolet detection was developed and validated for the simultaneous quantification of VFL and its active metabolite 4-O-deacetylvinflunine. The two compounds, together with 17-bromovinorelbine, used as an internal standard, were extracted from blood (1 mL) by a liquid-liquid process under basic conditions using diethyl ether. The organic phase was then back-extracted with HCl 0.1 mol/L. Analysis was performed through a cyano column and detection was set at 268 nm. Total analysis run time was less than 15 minutes. The assay was sensitive for the two compounds to at least 2 ng/mL and calibration curves were linear up to 200 ng/mL. The between-run imprecision and the mean inaccuracy were lower than 7% and 8.3%, respectively. Blood samples were stable when stored at -70°C over 24 months. The long-term reproducibility and the suitability of this analytical method were demonstrated through the analysis of about 6000 biologic samples during the clinical development of intravenous VFL. This method is adequately sensitive to monitor the blood concentrations observed at the recommended dose defined in a clinical setting.

Determination of milnacipran, a serotonin and noradrenaline reuptake inhibitor, in human plasma using liquid chromatography with spectrofluorimetric detection.

Milnacipran is an antidepressant drug belonging to the class of serotonin and noradrenaline reuptake inhibitors. A sensitive high performance liquid chromatographic during the development method coupled with a fluorimetric detection was set up, validated and then used routinely of the drug. After liquid-liquid extraction, milnacipran and its internal standard were analyzed by reversed-phase liquid chromatography (LC). The drug was derivatized with fluorescamine for fluorescence detection. The identity of the liquid chromatography peaks was controlled using mass spectrometry. The assay linearity was validated up to 1000 ng/ml. The limit of quantification was set at 5 ng/ml. Precision values (relative standard deviations) were lower than 5.4%, whereas the mean accuracy was higher than 95%. The extraction recoveries were higher than 70% for both milnacipran and the internal standard. In clinics, the LC-fluorescence method was routinely used to investigate the pharmacokinetics of milnacipran in patients and proved to be robust and capable of quantifying milnacipran in plasma for at least 36 h (four- to five-fold the elimination half-life).