Pharmacokinetics of vinorelbine in man

A Phase I Comparative Pharmacokinetic and Safety Study of Two Intravenous Formulations of Vinorelbine in Patients With Advanced Non-Small Cell Lung Cancer

Purpose: The aim of this study was to compare the pharmacokinetics and safety between two vinorelbine formulations [a new oil-in-water emulsion formulation (ANX) versus a previously marketed solution formulation (Navelbine)] in Chinese patients with advanced non-small cell lung cancer (NSCLC).

Method: This was a single-center, randomized, open-label study. Eligible patients aged 18–70 years who had histologically or cytologically confirmed NSCLC were enrolled. In cycle 1, the patients alternatively received the two formulations (30 mg/m², given as a 10-min infusion) with a 7-day interval. Samples for pharmacokinetic analysis were taken during cycle 1. For all subsequent 21-day cycles (maximum four cycles), ANX was administered on days 1 and day 8. Bioequivalence analysis was performed on C_max, AUC_last, and AUC_inf. The safety profiles and anti-tumor effects were also determined.

Results: From March 2013 to January 2015, 24 patients were enrolled and 20 were eligible for pharmacokinetic evaluation. The 20 subjects in the pharmacokinetic analysis set had a median age of 61 years (range, 37–70 years), and 15 patients were male (75%). Mean vinorelbine C_max values for ANX and Navelbine were 1,317.40 and 1,446.30 ng/mL, respectively. Corresponding AUC_last values were 797.08 and 924.26 ng·h/mL, respectively. AUC_inf values were 830.14 and 957.16 ng·h/mL, respectively. Treatment ratios of the geometric means were 90.00% (90% CI, 83.22–99.07%) for C_max, 86.92% (90% CI, 80.91–93.37%) for AUC_last, and 87.44% (90% CI, 82.08–93.16%) for AUC_inf. These results met the required 80–125% bioequivalence criteria. The most frequently reported adverse events after vinorelbine administration were neutropenia, leucopenia, neutropenic fever, and constipation.

Conclusion: At therapeutic dosage levels, pharmacokinetic behavior and safety profiles were similar for both formulations. Chinese National Registry Code: ChiCTR-IPR-15005856.

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.

Fatal iatrogenic vinorelbine poisoning: a case report

The paper describes the case of a 69-year-old man with non-small-cell lung cancer who, owing to a mistake, received intravenously 500 mg of vinorelbine. Within 3 days of intoxication, the bone marrow of the patient was damaged with subsequent pancytopenia that did not respond to treatment. On the fifth day after the poisoning, features of intestinal obstruction appeared. The patient died on the sixth day after the drug overdose. The case presented by us constitutes the first description of a fatal iatrogenic poisoning with this drug.

Increased risk of vincristine neurotoxicity associated with low CYP3A5 expression genotype in children with acute lymphoblastic leukemia

BACKGROUND

This study evaluates the relationship between cytochrome P450 (CYP) 3A5 genotype and vincristine-induced peripheral neuropathy (VIPN) in children with precursor B cell acute lymphoblastic leukemia (preB ALL). We have shown in vitro that vincristine is metabolized significantly more efficiently by CYP3A5 than by CYP3A4. We also found that vincristine neurotoxicity is less common in African-Americans (70% express CYP3A5) than in Caucasians. We test the hypothesis that CYP3A5 expressers experience less vincristine neuropathy than do CYP3A5 non-expressers.

PROCEDURE

This study of pharmacogenetics of vincristine neuropathy in children with preB ALL was completed at Indiana University Simon Cancer Center. Whole blood for DNA extraction and genotyping was collected as well as plasma from a single time-point for analysis of vincristine and primary metabolite (M1) concentrations. Vincristine neuropathy was captured via chart review and graded per the National Cancer Institute Common Terminology Criteria for Adverse Events, version 3.0.

RESULTS

Eighty-nine percent of CYP3A5 expressers experienced neurotoxicity versus 100% of non-expressers (P = 0.03). The proportion of treatment months with neurotoxicity was significantly different between the expressers and non-expressers (16% vs. 27%, P = 0.0007). Limited pharmacokinetic data suggest different rates of vincristine metabolism between CYP3A5 genotype groups with higher primary metabolite (M1) plasma concentrations (P = 0.0004) and lower metabolic ratios ([vincristine]/[M1]) (P = 0.036) in the CYP3A5 expressers compared to the CYP3A5 non-expressers. M1 concentration was also inversely related to severity of neuropathy (P = 0.0316).

CONCLUSIONS

In children with preB ALL, CYP3A5 expressers experience less VIPN, produce more M1, and have lower metabolic ratios compared to CYP3A5 non-expressers.

Osteonecrosis of the jaw related to sunitinib

CASE REPORT

A 59-year-old male patient was referred to the hospital with exposed bone measuring 10 mm in diameter in the posterior, left-side region of the lower jaw. Two months previous, the first molar had been extracted. The patient had contracted renal cell carcinoma and had been treated by nephrectomy in 2003. Soft tissue metastases occurred. After initial therapy with interferon and vinblastine, a relapse occurred and the therapy was changed to sorafenib, followed by sunitinib. Osteonecrosis of the lower jaw appeared 1 year after initial and exclusive therapy with sunitinib.

CONCLUSIONS

Bisphosphonates had never been applied. With increasing application of multi-kinase inhibitors, complications due to osteonecrosis could occur more frequently.

The bioanalysis of vinorelbine and 4-O-deacetylvinorelbine in human and mouse plasma using high-performance liquid chromatography coupled with heated electrospray ionization tandem mass-spectrometry

A sensitive, specific and efficient high-performance liquid chromatography/tandem mass spectrometry assay for the simultaneous determination of vinorelbine and its metabolite 4-O-deacetylvinorelbine in human and mouse plasma is presented. Heated electrospray ionization was applied followed by tandem mass spectrometry. A 50 microL plasma aliquot was protein precipitated with acetonitrile-methanol (1:1, v/v) containing the internal standard vinorelbine-d3 and 20 microL volumes were injected onto the HPLC system. Separation was achieved on a 50 x 2.1 mm i.d. Xbridge C(18) column using isocratic elution with 1 mm ammonium acetate-ammonia buffer pH 10.5-acetonitrile-methanol (28:12:60, v/v/v) at a flow rate of 0.4 mL/min. The HPLC run time was 5 min. The assay quantifies both vinorelbine and 4-O-deacetylvinorelbine from 0.1 to 100 ng/mL using sample volumes of only 50 microL. Mouse plasma samples can be quantified using calibration curves prepared in human plasma. Validation results demonstrate that vinorelbine and 4-O-deacetylvinorelbine can be accurately and precisely quantified in human and mouse plasma with the presented method. The assay is now in use to support (pre-)clinical pharmacologic studies with vinorelbine in humans and mice.

A sensitive assay for the quantitative analysis of vinorelbine in mouse and human EDTA plasma by high-performance liquid chromatography coupled with electrospray tandem mass spectrometry

A sensitive, specific and fast high-performance liquid chromatography/tandem mass spectrometry (HPLC-MS/MS) assay for the determination of vinorelbine in mouse and human plasma is presented. A 200 microL aliquot was extracted with solid-phase extraction (SPE) using Bond-Elut C(2) cartridges. Dried extracts were reconstituted in 100 microL 1 mM ammonium acetate pH 10.5-acetonitrile-methanol (21:9:70, v/v/v) containing the internal standard vintriptol (100 ng/mL) and 10 microL volumes were injected onto the HPLC system. Separation was achieved on a 50 mm x 2.0 mm i.d. Gemini C(18) column using isocratic elution with 1 mM ammonium acetate pH 10.5-acetonitrile-methanol (21:9:70, v/v/v) at a flow rate of 0.4 mL/min. HPLC run time was only 5 min. Detection was performed using positive ion electrospray ionization followed by tandem mass spectrometry (ESI-MS/MS). The assay quantifies vinorelbine from 0.1 to 100 ng/mL using human plasma sample volumes of 200 microL. With this method vinorelbine can be measured in mouse plasma samples when these samples are diluted eight times in control human plasma. Calibration samples prepared in control human plasma can be used for the quantification of the drug. The lower limit of quantification in mouse plasma is 0.8 ng/mL. This assay is used to support preclinical and clinical pharmacologic studies with vinorelbine.

Effect of race on vincristine-associated neurotoxicity in pediatric acute lymphoblastic leukemia patients

BACKGROUND

This report examines the association between race and vincristine-associated neurotoxicity in pediatric patients with precursor B cell acute lymphoblastic leukemia (preB ALL). Given that in vitro vincristine is metabolized more efficiently by cytochrome P450 (CYP) 3A5 than by CYP3A4 and that 70% African-Americans (vs. 20% of Caucasians) express CYP3A5, one may hypothesize that African-Americans metabolize vincristine more efficiently resulting in lower vincristine exposure and associated-toxicity.

PROCEDURE

A retrospective analysis of vincristine-related side effects in pediatric patients treated for preB ALL was performed. Data were compared between Caucasians (n = 92) and African-Americans (n = 21) to examine the relationship between race and vincristine-associated neurotoxicity thus using race as a surrogate for CYP3A5 genotype. Race, age, gender, disease subtype, highest grade of vincristine-associated neurotoxicity (per NIH Common Terminology Criteria for Adverse Events version 3.0), number of omitted and reduced vincristine doses, cumulative vincristine dose, and disease outcome were captured.

RESULTS

34.8% of Caucasians experienced symptoms consistent with vincristine-related neurotoxicity compared to 4.8% of African-Americans (P = 0.007). The average grade of neurotoxicity for Caucasians was 2.72 versus grade 1 neurotoxicity in the African-American (P < 0.0001). Four percent of total doses administered to Caucasian patients were reduced due to vincristine-related neurotoxicity compared to 0.1% given to African-Americans (P < 0.0001). 1.2% of all protocol-indicated doses for Caucasians were held due to severe vincristine-associated toxicity compared to 0.1% of doses for African-Americans (P < 0.01).

CONCLUSIONS

The data support the hypothesis pharmacogenetic polymorphisms in CYP3A5 expression contribute to variability in vincristine metabolism and neurotoxicity.

Pemetrexed pharmacokinetics and pharmacodynamics in a phase I/II study of doublet chemotherapy with vinorelbine: implications for further optimisation of pemetrexed schedules

The purpose of this study was to investigate the utility of plasma pharmacokinetic and pharmacodynamic measures including plasma deoxynucleosides, homocysteine and methylmalonic acid concentrations in understanding the time course and extent of the inhibition of thymidylate synthase (TS) by pemetrexed in the context of a phase I/II combination study with vinorelbine. Eighteen patients received supplementation with folic acid and Vitamin B₁₂ 1 week before beginning treatment with pemetrexed and vinorelbine administered in a dose-escalating manner on a 21-day cycle. Heparinised blood samples were collected from consenting patients in the first cycle for pharmacokinetic analyses and in the first two cycles for determination of plasma thymidine, deoxyuridine, homocysteine and methylmalonic acid concentrations. These values were correlated with response and toxicity. Plasma deoxyuridine was used as a measure of TS inhibition, and concentrations of deoxyuridine were significantly elevated relative to baseline on days 1 (P<0.01), 2 (P<0.001) and 3 (P<0.05) after treatment at all pemetrexed dose levels (400–700 mg m⁻²). The magnitude of deoxyuridine elevation correlated with pemetrexed area under the plasma concentration–time curve (AUC) (r²=0.23, P<0.05). However, deoxyuridine concentrations returned to baseline between 8 and 15 days after treatment with pemetrexed, suggesting that inhibition of TS was not durable. Pemetrexed AUC correlated with the percentage decline (relative to baseline) in both platelets (r²=0.58, P<0.001) and leucocytes (r²=0.26, P<0.05) at day 8. Baseline homocysteine was also significantly correlated with these measures of haematological toxicity (r²=0.37, P<0.01 and r²=0.39, P<0.01, respectively). In addition, there was a significant reduction of plasma homocysteine on days 8 (P<0.005) and 15 (P<0.05) in cycle 1 compared to baseline values. The results suggest that the TS inhibitory effects of pemetrexed are short-lived and make the case for a more frequent schedule of administration such as every 2 weeks. The lack of protracted TS inhibition may be due to concomitant vitamin administration, and this may be the mechanism by which vitamins prevent life-threatening toxicity from pemetrexed. Baseline homocysteine concentration remains a predictive marker for haematological toxicity even following folate supplementation.

Clinical pharmacology and use of microtubule-targeting agents in cancer therapy

The microtubule-targeting agents have made significant contributions to cancer therapy over the past 50 years. The vinca alkaloids and taxanes have been used to treat a broad range of malignancies, including leukemias and lymphomas and many types of solid tumors. The taxanes have been frequently used in the treatment of advanced ovarian, breast, lung, head and neck, and prostate cancer, and they are increasingly being used in early stage disease. This chapter reviews the pharmacology, clinical indications, and toxicities associated with the vinca alkaloids and taxanes.

Phase I Evaluation of Oral and Intravenous Vinorelbine in Pediatric Cancer Patients: A Report from the Children's Oncology Group

PURPOSE

Vinorelbine (Navelbine) is an orally absorbable Vinca with broad antitumor activity. It differs from other Vinca in that it is structurally modified on the catharanthine nucleus and has differential actions on tubulin that render it less neurotoxic than other compounds in this class. We conducted a phase I study of vinorelbine given the activity of Vinca alkaloids in many pediatric tumors.

EXPERIMENTAL DESIGN

We evaluated the safety and pharmacokinetics of oral and i.v. vinorelbine administered weekly x 6 in children (age, 2-17 years) with different tumors. Patients with disease involvement in the bone marrow were eligible but were stratified and dose-escalated separately. Oral vinorelbine (week 1) was administered as liquid-filled gelatin capsules at thrice the i.v. dose. Intravenous vinorelbine doses of 24 to 37.5 mg/m(2) were administered on weeks 2 to 6.

RESULTS

The dose-limiting toxicity in patients without marrow involvement was reversible neutropenia. Common nonhematologic toxicities included < or = grade 2 nausea/vomiting and increased hepatic transaminases. A higher mean i.v. Cl(TB) was observed (1.75 +/- 1.0 L/h/kg) compared with adult reports, with a mean t(1/2B) of 16.5 +/- 9.7 hours. Mean oral bioavailability was 28.5 +/- 22.5%. The apparent oral clearance (12.1 +/- 13.0 L/h/kg) and volume of distribution (69.4 +/- 30.6 L/kg) were substantially higher than in adults given similar oral doses.

CONCLUSIONS

The maximum tolerated dose in children without bone marrow involvement was 30 mg/m(2), similar to that reported in adults, with myelosuppression being the dose-limiting toxicity. Higher plasma clearance resulted in lower area under the plasma concentration-time curves at a given dose compared with that reported in adults.

Combination vinorelbine and capecitabine for metastatic breast cancer using a non-body surface area dosing scheme

PURPOSE

This study sought to determine the maximum tolerated dose of flat-dosed vinorelbine in combination with capecitabine in patients with metastatic breast cancer. At the time of study initiation, it was anticipated that vinorelbine would be developed as an oral capsule. A flat dosing scheme of both drugs was used to facilitate development of the oral regimen, and because neither drug's clearance is associated with body surface area (BSA), pharmacokinetic and pharmacogenetic endpoints were explored.

EXPERIMENTAL DESIGN

Capecitabine was administered orally at 3,000 mg/day on days 1-14. The starting dose of vinorelbine was 20 mg intravenously on days 1 and 8 of a 21-day cycle. The vinorelbine dose was escalated until dose limiting toxicity (DLT). Vinorelbine pharmacokinetics were measured after the first dose. Patients underwent genotype analysis for polymorphisms in the CYP3A5 gene, and the erythromycin breath test (ERMBT), a phenotypic test of CYP3A enzyme activity.

RESULTS

Twenty five eligible patients were enrolled. Hematologic DLT was seen at the 50 and 45 mg vinorelbine doses; thus the recommended dose is 40 mg on days 1 and 8. Response rate was 30%, and disease stabilization rate was 64% (all dose levels included). Vinorelbine clearance was not associated with ERMBT, BSA, or age. CYP3A5 genotype in this small sample did not have an obvious relationship to clearance or toxicity.

CONCLUSIONS

A non-BSA based dosing scheme of capecitabine and vinorelbine is safe and efficacious. BSA did not affect vinorelbine clearance. We recommend future studies with capecitabine and/or vinorelbine to compare the safety and efficacy of flat dosed versus BSA-dosed treatment.

Potential activity of paclitaxel, vinorelbine and gemcitabine in anaplastic thyroid carcinoma

Anaplastic thyroid carcinoma (ATC) has a rapidly fatal course in the mostly elderly patients with a median survival after diagnosis of 4-12 months. Activity of commonly used chemotherapy (doxorubicin) is low, thus more active compounds need to be introduced into the therapeutic concept of ATC. Recently, based on preclinical data Ain et al. conducted a clinical phase II study with paclitaxel 96 h infusion in ATC achieving a promising response rate of 53%. To further improve therapeutic options in ATC, we evaluated the activity of topotecan, oxaliplatin, vinorelbine, gemcitabine and paclitaxel in comparision to cisplatin and doxorubicin (1 and 96 h drug exposure) alone or in combination in the ATC cell lines SW1736 and 8505C. IC50 values were determined by the sulforhodamine B assay, potential clinical activity was estimated by relative antitumor activity (RAA) and drug interaction was analyzed using a parametric response surface approach (Greco model) of the Loewe additivity. Duration of drug effect was estimated by regrowth kinetics. We found paclitaxel, vinorelbine and gemcitabine active in ATC with RAA (1 h drug exposure) ranging from 86 to 454, 15 to 17 and 31 to 140, respectively. The activity of doxorubicin and cisplatin was moderate with RAA ranging from 1.4 to 2.2 and 0.2 to 0.3, respectively. Combined drug exposure of gemcitabine/paclitaxel and gemcitabine/vinorelbine was synergistic with a Loewe index > 0. However, these results did not reach statistical significance with p > 0.05. At clinically relevant drug concentrations paclitaxel, gemcitabine and vinorelbine but not oxaliplatin exerted a sustained growth inhibition after cessation of drug exposure for the complete assay time of 15 days. In conclusion, paclitaxel, gemcitabine and vinorelbine but not topotecan or oxaliplatin appeared to be active in anaplastic thyroid carcinoma based on RAA or growth delay at clinically relevant drug concentrations. Combinations of vinorelbine/gemcitabine and paclitaxel/gemcitabine exerted a trend to synergy. Thus, further evaluation of paclitaxel, vinorelbine and gemcitabine alone or in combination with ATC seems warranted.

Oral versus intravenous vinorelbine: clinical safety profile

The availability of chemotherapeutic drugs administrable by oral route represents a step forward in the management of cancer patients. Among oral agents, vinorelbine is particularly interesting for its pharmacological characteristics and clinical efficacy. Oral vinorelbine is rapidly absorbed (1.5-3 hours) with an elimination half-life of approximately 40 hours. It shows a low level of binding to plasma proteins (13%), is highly bound to platelets (78%) and has a hepatic metabolism and an absolute bioavailability of 40% with a moderate and similar interpatient variability for the two forms. Food has no influence on the pharmacokinetic profile of oral vinorelbine even if nausea/vomiting is less frequent and less severe in the fed patients than in the fasting patients. Therefore, to ensure patient comfort, it is recommended that oral vinorelbine is administered with a snack. All the metabolites of oral vinorelbine have been identified and, among these, only deacetyl-vinorelbine presented activity demonstrating that for both oral and intravenous (i.v.) routes of administration the drug has the same metabolism pattern. Oral vinorelbine is eliminated mainly in a unconjugated form via the bile. In this process, the CYP 3A4 isoform of cytochrome P450 is mostly involved. Absorption of oral vinorelbine is not delayed in elderly patients. After oral administration, blood concentrations of vinorelbine in elderly patients are within the range of values observed in younger patients. The absolute bioavailability is close to 38% in elderly whereas it is close to 40% in younger patients. This difference is not significant. As compared to the intravenous drug, oral vinorelbine demonstrated linear pharmacokinetics as well an absolute bioavailability of approximately 40%, and a reliable dose-correspondence of 80 mg/m2 oral form --> 30 mg/m2 i.v. and 60 mg/m2 oral --> 25 mg/m2 i.v. Therefore, i.v. and oral forms show similar interindividual variability, same metabolism pattern, reproducible intra-patient blood exposure, and same pharmacokinetic-pharmacodynamic relationship. Oral vinorelbine has shown significant activity in advanced non-small cell lung cancer. Given at 60 mg/m2/week for the first 3 administrations and then increased to 80 mg/m2/week achieved the same efficacy as i.v. vinorelbine in terms of progression-free survival, overall survival, objective response. Mild-to-moderate gastrointestinal toxicity, easily manageable with standard treatment was recorded. Reproducible efficacy compared to previously reported results with vinorelbine i.v. Also, in advanced breast cancer, oral vinorelbine has shown significant activity with a good therapeutic index. Albeit no formal comparison between the oral and the intravenous formulations of vinorelbine has been made, however, the oral route seems to offer major advantages to patients who are faced with a clear decrease in the frequency of hospital admissions as compared to that needed to give intravenous chemotherapy.

Prediction of human pharmacokinetics from animal data and molecular structural parameters using multivariate regression analysis: volume of distribution at steady state

The aim of this study was to develop a regression equation for predicting volume of distribution at steady state (Vd(ss)) in humans to enable application to various types of drugs using animal experimental data for rats and dogs and some molecular structural parameters. The Vd(ss) data for rats, dogs and humans of 64 drugs were obtained from literature. The compounds have various structures, pharmacological activities and pharmacokinetic characteristics. In addition, the molecular weight, calculated partition coefficient (clogP), and the number of hydrogen bond acceptors were used as possible descriptors related to the Vd(ss) in humans. Multivariate regression analyses, multiple linear regression analysis and the partial least squares (PLS) method were used to predict Vd(ss) in humans. Interaction terms were also introduced into the regression analysis to evaluate the non-linear relationship. For the data set used in the present study, PLS with quadratic term descriptors gave the best predictive performance. The PLS model using Vd(ss) data for only two animal species and using easily calculated structural parameters could generally predict Vd(ss) in humans better than an allometric method. In addition, the PLS model with only animal data gave almost the same predictive performance as the PLS model with quadratic term descriptors. This model may be easier to use and be practical in a realistic situation, and could predict Vd(ss) in humans better than the allometric method.

Vinorelbine: a review of its use in elderly patients with advanced non-small cell lung cancer

Vinorelbine is a semisynthetic vinca alkaloid that is effective as monotherapy in elderly patients with advanced non-small cell lung cancer (NSCLC). In the large comparative Elderly Lung Cancer Vinorelbine Italian Study (ELVIS), patients receiving vinorelbine monotherapy achieved an objective response rate of 19.7%. The median survival time and the 1-year survival rate were significantly higher in recipients of vinorelbine plus best supportive care than in recipients of best supportive care alone. Vinorelbine recipients generally scored better than recipients of best supportive care on quality-of-life (QOL) functioning scales and experienced significantly fewer lung cancer-related symptoms; however, QOL scores were worse with vinorelbine for parameters relating to drug tolerability. Comparative phase III trials investigating the efficacy of combination therapy with vinorelbine and other agents specifically in elderly patients with advanced NSCLC have been conducted only for the combination of vinorelbine and gemcitabine [the Southern Italy Cooperative Oncology Group (SICOG) trial and the Multicenter Italian Lung Cancer in the Elderly Study (MILES)]. Objective response rates for vinorelbine/gemcitabine combination therapy in these phase III trials were 22 and 20%, respectively. The SICOG trial was closed early when an interim analysis demonstrated a significant survival advantage for combination therapy with vinorelbine plus gemcitabine over vinorelbine monotherapy. However, a survival advantage for combination therapy versus vinorelbine monotherapy was not demonstrated in the larger MILES trial. The main adverse effect of vinorelbine monotherapy in the elderly is myelosuppression. Adverse events associated with most antineoplastic agents, such as mild alopecia, nausea, vomiting and mucositis, were reported in clinical trials; however, these events were rarely severe. Mild-to-moderate neurotoxicity, including constipation (presumably from autonomic neuropathy), was also reported. The addition of gemcitabine to vinorelbine increased the incidence of both haematological and nonhaematological adverse events. However, there was no significant increase in the incidence of life-threatening toxicity. Vinorelbine as a single agent is effective in elderly patients with NSCLC and is associated with improved survival and at least a trend towards improved QOL parameters compared with best supportive care alone. Vinorelbine was associated with a generally manageable tolerability profile. The benefit of adding gemcitabine to vinorelbine for the treatment of NSCLC in the elderly is equivocal; improved survival was reported in one comparative trial, but not in another larger one. Vinorelbine is an effective and well tolerated palliative treatment option for elderly patients with advanced NSCLC.

An animal model for the study of chronopharmacokinetics of drugs and application to methotrexate and vinorelbine

An animal model was designed to study the chronopharmacokinetics of intravenous drugs and applied to anticancer agents vinorelbine (VNB) and methotrexate (MTX). Each experiment was performed on four pigs housed in a standardized light-dark cycle (12:12). Four pigs received a 0.16-mg bolus of VNB, followed by a 60-h continuous infusion at 0.48 mg/h. After hydration and urine alkalinization, four other pigs received a 2 mg/kg bolus of MTX, followed by two concomitant 60-h continuous infusions, one with MTX (8 mg/kg/h) and the other for hydration and folinic acid rescue (1.5 mg/kg/24 h). Serum cortisol was determined in each blood sample collected in these pigs. Blood samples were collected each hour for 60 h. The infusion flow rates and drug solution concentrations were controlled throughout the experiments. Analysis of VNB serum concentrations did not show any circadian rhythm of VNB serum concentrations. One pig administered MTX exhibited severe toxicity. Interestingly, no circadian rhythm of serum cortisol concentration was observed in this pig, whereas the three others exhibited a statistically significant cortisol circadian rhythm with a peak secretion in the morning. Two of these three pigs showed a significant 24-h rhythm of MTX with acrophase occurring at approximately 1:00 PM in both. The maximal concentration was found at 12:00 AM in the third pig. After the data were pooled, a highly significant (P < 0.01) circadian rhythm in MTX serum concentrations (57%) was found, with acrophase at midday. The pig represents a useful model for the study of chronopharmacokinetics of drugs given intravenously in human. The MTX chronokinetic variation found herein may be of interest for the improvement of chemotherapy in cancer patients.

A limited-sampling strategy to estimate individual pharmacokinetic parameters of vinorelbine in elderly patients with advanced metastatic cancer

The aim of this study was to characterize the population pharmacokinetic of vinorelbine in elderly patients and to propose a limited-sampling strategy to estimate individual pharmacokinetic parameters. Vinorelbine was administered by a 10-min continuous infusion at a dose of 20-30 mg/m2. The population parameters were computed, using a three-compartment model, from an initial group of 27 patients. Twelve additional courses were used for model validation and evaluation of eight different limited-sampling strategies. The inter-individual variability of CL was explained by a linear dependency with age. The population average parameters and the interindividual variabilities (CV%) were: CL=47.1 l/h (31.7%), V=16.6 l (64%), k21=0.776 h-1 (20%), k31=0.0346 h-1 (15.2%), alpha=0.431 h-1 (6.84%) and beta=0.0167 h-1 (25%). Bayesian estimation with three measured levels (end of infusion, and 6 and 48 h) can be selected, because it allows adequate estimation of CL, elimination half-life and vinorelbine concentrations with a non-significant bias. Moreover, the choice of these three sampling times presents practicality advantages for the patient's comfort. Vinorelbine clearance decreasing with age and AUC being a good predictor of several toxicity end points during vinorelbine treatment, the limited-sampling strategy developed in this paper may be clinically relevant.

Sensitive determination of vinorelbine and its metabolites in human serum using liquid chromatography-electrospray mass spectrometry

A liquid chromatography-electrospray mass spectrometry method was developed for the quantitation of vinorelbine (VNB) and two metabolites, vinorelbine N-oxide (VNO) and deacetyl vinorelbine (DAV) in human serum. The limits of quantitation (LOQ) reached 0.5 ng/ml for both VNB and VNO and 1 ng/ml for DAV. The method was proved linear in the range of LOQs up to 1000 ng/ml, and extraction recovery was 80% on average for the three compounds. It was applied to the pharmacokinetic monitoring of vinorelbine and, for the first time, to the detection of VNO in the serum of patients suffering from non-small-cell lung cancer.

Schedule-dependent interactions between vinorelbine and paclitaxel in human carcinoma cell lines in vitro

Vinorelbine and paclitaxel are new anticancer agents that bind to distinct sites on tubulin and affect microtubules in opposite ways. Clinical studies of combinations of these agents have been in progress against breast cancer and some solid tumors. To clarify the optimal schedule for this combination, we studied the schedule-dependent cytotoxic effects of vinorelbine and paclitaxel against the human lung carcinoma cell line A549, the breast carcinoma cell line MCF7, the ovarian carcinoma cell line PA1, and the colon carcinoma cell line WiDr in vitro. Tumor cells were incubated with vinorelbine and paclitaxel simultaneously for both 24 h and 5 days. Cells were also incubated with vinorelbine for 24 h, followed by a 24-h exposure to paclitaxel and vice versa. Cell growth inhibition after 5 days was determined by MTT assay. The effects of drug combinations at the concentration producing 80% cell growth inhibition (IC80) were analyzed by the isobologram method (Steel and Peckham). The simultaneous exposures to vinorelbine and paclitaxel for both 24 h and 5 days produced additive effects for all four cell lines. The sequential exposure to vinorelbine followed by paclitaxel produced additive effects for the PA1 and WiDr cells, additive and antagonistic effects for the A549 cells, and antagonistic effects for the MCF7 cells. The sequential exposure to paclitaxel followed by vinorelbine produced additive effects for the A549, and PA1 cells, additive and antagonistic effects for the MCF7 cells, and antagonistic effects for the WiDr cells. Our findings suggest that the simultaneous rather than the sequential administration of vinorelbine and paclitaxel may be the optimal schedule for this combination of these two agents. Applications of this schedule dependency may be beneficial for the treatment of breast cancer and other solid tumors.

Combination cisplatin-vinorelbine for relapsed and chemotherapy-pretreated metastatic breast cancer

The purpose of this study was to evaluate the combination of cisplatin and vinorelbine (PVn) for relapsed and chemotherapy-pretreated metastatic breast cancer. Twenty-three patients with metastatic breast cancer and prior chemotherapy were entered in a phase II study between June 1993 and December 1994. Eleven patients were premenopausal and 12 were postmenopausal. Follow-up data up to June 1997 are presented. All patients received cisplatin at a dose of 90 mg/m2 divided over 3 days as 30 mg/m2 infused over 4 hours. Intravenous vinorelbine 25 mg/m2 was given on days 1 and 8 or 15 according to patients' blood counts. Cycles were given every 3 to 4 weeks. An overall response rate of 61% (16/23 patients) was observed. Complete remission was obtained in six patients (26%) and partial remission was obtained in nine patients (35%). The duration of response ranged from 3 to 9 months, with an average of 4 months. Stable disease was noted in 29.1% and progressive disease in 8.3%. Overall survival at 12 months was 50%, and at 36 months it was 8%. Five of 12 patients (42%) who had prior doxorubicin therapy responded well to cisplatin-vinorelbine. Of those 12, seven were refractory and progressive on a doxorubicin-containing regimen, one had complete remission, and four had partial remission. Hematologic toxicity was acceptable. Treatment was delayed because of neutropenia in nine cycles (9.2%) and grade 2 leukopenia occurred in 54% of cycles. Febrile neutropenia occurred in seven cycles (7.1%), and five cycles were complicated by documented sepsis (5.1%). No treatment-related mortality occurred. Thrombocytopenia (grade 3) was seen in 27% of cycles, with no patient having a platelet count below 50,000 or bleeding episodes. Other toxicities were not major or dose-limiting. In conclusion, the combination of cisplatin and vinorelbine produced good responses: 61% response rate (16 of 23 patients) in relapsed, refractory, and heavily pretreated metastatic breast cancer, with 50% survival at 1 year, 12% at 2 years, and 8% at 3 years. In addition, a response rate of 42% (5 of 12 patients) was seen in patients resistant to anthracyclines.

Vinorelbine (Navelbine): a third-generation vinca alkaloid

The vinca alkaloids represent one of the oldest classes of antineoplastic agents used in humans with a wide spectrum of activity against both animal and human tumors. These agents are known to inhibit microtubule polymerization. Vinorelbine is a semisynthetic analog that reached clinical trial on the basis of less preclinical evidence of toxicity to neuronal tissue and greater cytotoxic activity in preclinical models than the older compounds of this class. In humans, the clearance of this agent shows a wide variation among subjects with the predominant toxicity being hematological. Significant antitumor activity has been observed in diseases that previously have been shown to respond to vinca alkaloids.

Pharmacokinetics and tolerance of vinorelbine in elderly patients with metastatic breast cancer

25 patients older than 65 years with metastatic breast cancer were treated with vinorelbine 30 mg/m2 i.v. days 1 and 8 every 3 weeks; the pharmacokinetics were studied in 10 of them. Vinorelbine showed a large apparent volume of distribution (mean 23.4 l/kg), a long terminal half-life (mean 26.2 h) and a large systemic clearance rate (mean 1.2 l/kg). These results are similar to those reported in younger patients. No correlation has been found between toxicity, age and drug exposure. We observed 6 partial responses out of 20 evaluable patients despite a relatively low mean dose intensity (67%). Severe neutropenia occurred in 37% of the patients; other side-effects were acceptable. This study does not provide a pharmacokinetic rationale for reducing the dosage of vinorelbine in selected elderly patients.

Pharmacokinetics of vinorelbine in patients with liver metastases

BACKGROUND

The main elimination pathway of vinorelbine is hepatic metabolism, and the clearance of vinorelbine could be reduced in patients with liver metastases.

OBJECTIVES

To study the pharmacokinetics of vinorelbine in patients who have advanced breast cancer with or without liver metastases and to study the relationship between hepatic function and vinorelbine clearance.

PATIENTS AND METHODS

We studied 29 patients with advanced breast cancer: 19 with liver metastases and 10 control patients with extrahepatic metastases (mean age, 61 years; age range, 38 to 81 years). The vinorelbine dose was 30 mg/m2 as a short intravenous infusion; the dose was reduced by 50% in patients with bilirubin > 2 mg/dl. Patients were classified by ultrasonographic estimation of the liver volume replaced by tumor (%LVRT). Standard liver function tests and a monoethylglycinexylidide test (a quantitative liver function test based on lidocaine metabolite formation) were performed. Vinorelbine was assayed in plasma by HPLC with fluorescence detection. Vinorelbine determination was impossible in two patients with more than 75% LVRT because of interferences. Pharmacokinetic parameters were calculated with a noncompartimental method and compared by means of the Kruskal-Wallis test.

RESULTS

A lower vinorelbine clearance rate was observed in the five patients with more than 75% LVRT (22.9 L/hr/m2) compared with the 10 patients with no liver metastases (48.0 L/hr/m2) and the 12 patients with 25% to 75% LVRT (45.3 L/hr/m2). Terminal elimination half-life and apparent volume of distribution were not significantly different among groups. The monoethylglycinexylidide test had a significant correlation with vinorelbine clearance. (r2 = 0.70; p = 10(-4).

CONCLUSIONS

These results support vinorelbine dose reduction in patients with severe liver failure but not in patients with moderate secondary liver involvement. The monoethylglycinexylidide test may prove to be useful for vinorelbine dose individualization.