Oral vinorelbine pharmacokinetics and absolute bioavailability study in patients with solid tumors

Phase II trial of oral vinorelbine for the treatment of metastatic breast cancer in patients ≥65 years of age: an NCCTG study

BACKGROUND

A one-stage phase II trial was conducted to assess the tumor response rate and toxicity profile of single agent oral vinorelbine as first or second-line chemotherapy for women at least 65 years of age with metastatic breast cancer.

PATIENTS AND METHODS

Twenty-five patients with metastatic breast cancer aged > or = 65 years of age were enrolled to receive oral vinorelbine on a weekly basis. The oral vinorelbine was given at 60 mg/m2 weekly for the first four doses and was increased to 70 mg/m2 for the subsequent administrations if there was no grade 4 neutropenia or no more than one episode of grade 3 neutropenia. Therapy was continued until progression or intolerable toxicity.

RESULTS

Twenty-five patients were included and evaluable for analysis. One patient (4%) achieved a partial response (PR) that lasted for more than 13 months. Two additional patients remained stable for at least 6 months for a clinical benefit rate (PR + stable disease) of 12%. The 1-year survival rate was estimated to be 48% (95% CI 30% to 74.5%). Median time to progression was estimated to be 4.7 months (95% CI 2.0-5.5 months) and the 9-month disease progression-free rate was estimated to be 8% (95% CI 30.9% to 74.5%). The treatment was fairly well tolerated with grade 3 neutropenia in 12.5%, fatigue in 12.5% of the patients, and grade 2 neuromotor and neurosensory toxicities in 12.5% and 8.3%, respectively.

CONCLUSION

Oral vinorelbine as a single agent at these dose and schedule in this population of women > or = 65 years is well tolerated but has a low level of objective efficacy for the treatment of metastatic breast cancer.

Vinorelbine in the management of breast cancer: New perspectives, revived role in the era of targeted therapy

Vinorelbine is a semi-synthetic vinca alkaloid that has been shown active in many tumour types and is currently registered for the treatment of advanced breast cancer (ABC) and non-small cell lung cancer (NSCLC). This agent has a generally favourable safety profile, and may be suitable for use in special populations such as the elderly and/or frail patient. However, with the taxanes firmly established as standard second line treatment for ABC after failure of an anthracycline, vinorelbine has been generally relegated for use as third line therapy, in competition with the oral compound capecitabine. More recently, the exciting results observed with the combination of vinorelbine and trastuzumab in patients with Her-2 overexpressing/amplified tumours, as well as the development of a reliable formulation and revised schedule of oral vinorelbine with proven activity in ABC appear to have revived the interest in this compound in the management of this disease. There are still a number of unanswered questions that will have to be addressed by properly designed, adequately powered randomised clinical trials.

Oral Vinorelbine and Cisplatin with Concomitant Radiotherapy in Stage III Non-Small Cell Lung Cancer (NSCLC): A Feasibility Study

BACKGROUND

Concurrent chemoradiotherapy has improved survival in inoperable stage III non-small cell lung cancer (NSCLC). This phase I trial was performed in order to establish a dose recommendation for oral vinorelbine in combination with cisplatin and simultaneous radiotherapy.

PATIENTS AND METHODS

Previously untreated patients with stage IIIB NSCLC received concurrent chemoradiotherapy with 66 Gy and 2 cycles of cisplatin and oral vinorelbine which was administered at 3 different levels (40, 50 and 60 mg/m2). This was to be followed by 2 cycles of cisplatin/ vinorelbine oral consolidation chemotherapy. The study goal was to determine the maximal recommended dose of oral vinorelbine during concurrent treatment.

RESULTS

11 stage IIIB patients were entered into the study. The median radiotherapy dose was 66 Gy. Grade 3-4 toxicity included neutropenia, esophagitis, gastritis and febrile neutropenia. The dose-limiting toxicity for concurrent chemoradiotherapy was esophagitis. 9 patients received consolidation chemotherapy, with neutropenia and anemia/thrombocytopenia grade 3 being the only toxicities. The overall response was 73%.

CONCLUSION

Oral vinorelbine 50 mg/m2 (days 1, 8, 15 over 4 weeks) in combination with cisplatin 20 mg/m2 (days 1-4) is the recommended dose in combination with radiotherapy (66 Gy) and will be used for concurrent chemoradiotherapy in a forthcoming phase III trial testing the efficacy of consolidation chemotherapy in patients not progressing after chemoradiotherapy.

[Oral vinorelbine: pharmacology and treatment outcome in non-small cell bronchial carcinoma and breast carcinoma]

The development of an oral formulation of vinorelbine (Navelbine softgelatine capsules, Pierre Fabre Pharma, Freiburg i.Br., Germany) represents a significant advance in the treatment of patients with cancer. Oral chemotherapy is more convenient for the patients and brings significant time savings. Vinorelbine is rapidly absorbed after oral ingestion. The bioavailability is in the range of 33 to 43% and is not affected by concomitant food intake or by vomiting occuring 1.5 h or later after dosing. No significant differences in the pharmacokinetics of oral vinorelbine were observed between elderly (> or =70 years) and younger patients. The recommended dose schedule for oral vinorelbine is 60 mg/m(2) weekly for the initial 3 weeks (cycle 1) and 80 mg/m(2) weekly thereafter. However, if severe neutropenia is encountered during the first cycle, treatment is continued with weekly doses of 60 mg/m(2). Bioavailability studies have demonstrated that oral vinorelbine doses of 60 and 80 mg/m(2) are comparable to intravenous doses of 25 and 30 mg/m(2), respectively. Several clinical studies have demonstrated that the new oral formulation of vinorelbine can be safely administered, even to elderly patients, and is comparable in activity to intravenous vinorelbine in advanced non-small cell lung cancer (NSCLC) and metastatic breast cancer (MBC). A randomized phase II comparison of oral vinorelbine at the recommended dose schedule vs. intravenous vinorelbine at 30 mg/(2) in patients with advanced NSCLC found no significant differences in response rate, progression-free and overall survival between the two treatments. In studies of combination chemotherapy using vinorelbine plus cisplatin or carboplatin in advanced NSCLC, or vinorelbine plus taxanes, capecitabine,epirubicin, or the monoclonal HER2/neu antibody trastuzumab in MBC, intravenous vinorelbine could be completely or partially replaced by oral vinorelbine, resulting in maintained efficacy, good tolerability and improved patient convenience. Concurrent chemoradiation with oral vinorelbine and cisplatin was shown to be well tolerated and produced significant down-staging in patients with locally advanced NSCLC. Metronomic chemotherapy is a new treatment approach designed to maximize the antiangiogenic effect. Oral vinorelbine given every other day at low doses is currently evaluated in patients with refractory solid tumors. Oral vinorelbine has also proven useful as a substitute for intravenous vinorelbine in patients experiencing intractable acute tumor pain during or after intravenous infusion of vinorelbine.

Dose-finding and pharmacokinetic study of an all-oral combination regimen of oral vinorelbine and capecitabine for patients with metastatic breast cancer

PURPOSE

A phase I study was performed to determine the maximal tolerated dose, recommended doses (RDs), safety and efficacy of oral vinorelbine when combined with capecitabine in an all-oral chemotherapy regimen in patients with metastatic breast cancer (MBC), with pharmacokinetic blood sampling to investigate potential drug-drug interactions.

PATIENTS AND METHODS

Forty-four patients with MBC received as first- or second-line chemotherapy, oral vinorelbine at a dose of 60 or 80 mg/m2 on days 1 and 8 (and 15) with escalating doses of capecitabine from 1650 to 2500 mg/m2/day days 1-14 every 3 or 4 weeks. Three schedules were tested: day 1, day 8 and weekly regimens of oral vinorelbine with a 14-day course of capecitabine every 3 weeks; and a days 1 and 8 regimen of oral vinorelbine with a 14-day course of capecitabine every 4 weeks.

RESULTS

With oral vinorelbine at 60 mg/m2, the RDs were established as oral vinorelbine 60 mg/m2 on days 1 and 8 plus capecitabine 2250 mg/m2/day days 1-14 and oral vinorelbine 60 mg/m2/week plus capecitabine 2000 mg/m2/day days 1-14. With oral vinorelbine at 80 mg/m2, the RD was oral vinorelbine 80 mg/m2 on days 1 and 8 plus capecitabine 2000 mg/m2/day days 1-14. Neutropenia was the main dose-limiting toxicity of the combination; it was reported in 40 patients (90.9%), with grade 3 in 14 patients (31.8%) and 6.2% of cycles, and grade 4 in 12 patients (27.3%) and 4.3% of cycles. Complications were rare with only three patients experiencing febrile neutropenia (one episode each). The most frequent non-haematological toxicity was gastrointestinal; however, the incidence of grade 3 was low, with no episode of grade 4. Hand-foot syndrome was reported in 14 patients (31.8%) and 22.6% of cycles, with grade 2 in two patients (4.5%) and 1.2% of cycles (two episodes each). No episode of grade 3 was observed. Objective responses were reported in 18 patients (three complete responses and 15 partial responses), yielding a response rate of 40.9% in the intention-to-treat population according to the investigator assessment. Results from the pharmacokinetic study demonstrated the absence of mutual pharmacokinetic interactions when both drugs were co-administered.

CONCLUSIONS

The combination of oral vinorelbine and capecitabine is safe and easy to administer in an outpatient setting. This all-oral combination chemotherapy may offer a good alternative to the intravenous route for patients with MBC. Based on these promising results, a phase II study has started using oral vinorelbine 60 mg/m2/week with capecitabine 2000 mg/m2/day days 1-14 every 3 weeks as first-line chemotherapy in patients with MBC.

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.

Vinorelbine alternating oral and intravenous plus epirubicin in first-line therapy of metastatic breast cancer: results of a multicentre phase II study

The combination of intravenous (i.v.) vinorelbine and epirubicin is highly active in the treatment of metastatic breast cancer (MBC). In an effort to improve patient convenience, we investigated a regimen alternating i.v. and oral vinorelbine in combination with epirubicin as first-line chemotherapy of patients with MBC. In all, 49 patients with MBC received, as first-line treatment, a combination regimen consisting of i.v. vinorelbine 25 mg m⁻² plus epirubicin 90 mg m⁻² given on day 1, and oral vinorelbine 60 mg m⁻² on day 8 (or day 15 if neutrophils <1500 mm⁻³) every 3 weeks, in an open-label, multicentre phase II study. Treatment was to be repeated for a maximum of six cycles. The study population had a median age of 55 years, half of the patients had received prior adjuvant chemotherapy and 86% presented a visceral involvement. In all, 25 responses were documented and validated by an independent panel review, yielding response rates of 51% (95% CI: 36–66) in the 49 enrolled patients and 54.5% (95% CI: 39–70) in the 44 evaluable patients. Median durations of progression-free survival and survival were 8 and 20 months, respectively. Neutropenia was the main dose-limiting toxicity, but complications were uncommon, four patients having experienced febrile neutropenia and six having developed neutropenic infection. Other frequently reported adverse events included stomatitis, nausea and vomiting, which were rarely severe. No toxic death was reported. Among patients who received six cycles, global score of quality of life remained stable. This regimen alternating oral and i.v. vinorelbine in combination with epirubicin is effective and safe. Oral vinorelbine on day 8 offers greater convenience to the patient, and decreases the need for i.v. injection and reduces time spent in hospital. Therefore, oral vinorelbine is a convenient alternative to the i.v. form in combination regimens commonly used to treat MBC.

The absolute bioavailability of oral vinorelbine in patients with solid tumors

Due to advances in the methods used to quantitate vinorelbine, this study was conducted to characterize fully the bioavailability of an oral dosage form of vinorelbine. Twenty-seven eligible patients with solid tumors were enrolled onto this study and were treated in a randomized crossover design to receive either 70 mg/m2 orally or 30 mg/m2 intravenously followed by the alternative treatment one week later. Vinorelbine was administered orally as a soft-gelatin capsule. Pharmacokinetic sampling was carried out for 7 days following each dose. Whole blood vinorelbine concentrations were measured using a sensitive LC/MS/MS method. The data from patients were excluded if they vomited within 3 h after the oral dose.

RESULTS

Three subjects were removed from study following the first dose due to safety reasons. Of the remaining 24 subjects, five experienced vomiting within 3 h of oral dosing. Total body clearance calculated from the intravenous dose was 43.65 L/h (+/-10.9) and the terminal half-life was estimated to be 49 h. Using complete data from the remaining 19 subjects, the mean absolute bioavailability of the oral dosage formulation of vinorelbine was calculated to be 33% (+/-18%). In conclusion we have characterized the pharmacokinetics of both orally administered and intravenous vinorelbine over 7 days after administration and have determined the mean oral bioavailability of this oral formulation to be 33%.

Oral vinorelbine given as monotherapy to advanced, elderly NSCLC patients: a multicentre phase II trial

Vinorelbine intravenously (i.v.) demonstrated its efficacy and tolerability in advanced non-small cell lung cancer (NSCLC) patients, including elderly subjects. Since vinorelbine is now available as an oral formulation this phase II open study was designed to evaluate its activity and tolerability in advanced, elderly NSCLC patients. A total of 56 chemonaive patients were recruited from April 2001 through to March 2002. The dosage schedule, already tested in younger NSCLC patients, was 60 mg/m(2)once a week for three weeks (first cycle), followed by 80 mg/m(2) once a week until disease progression or development of unacceptable toxicity. A limited sampling scheme was used for performing pharmacokinetic analysis on 52 of 56 patients enrolled in the study. Treatment was well tolerated with grade 3/4 neutropenia in 11/17 patients (20/30%) and febrile neutropenia in 1 (2%). Six partial responses (11%) and 25 stable disease responses were recorded, with a disease control rate of 55%. Median overall survival was 8.2 months (95% Confidence Interval (CI) [6.2-11.3]). The clinical benefit response rate was 31% on 32 evaluable patients. Pharmacokinetic profiles appeared quite similar to the historical profiles recorded following i.v. administration. Oral vinorelbine appears to be a reasonable alternative to i.v. vinorelbine, both in terms of activity and tolerability, in advanced, elderly NSCLC patients.

Vinorelbine alternating oral and intravenous plus carboplatinin advanced non-small-cell lung cancer: results of a multicentre phase II study

BACKGROUND

Vinorelbine and carboplatin are both active agents in the treatment of non-small-cell lung cancer (NSCLC). Vinorelbine has recently been developed in an oral formulation, which is as active as the intravenous (i.v.) form.

PATIENTS AND METHODS

Fifty-two chemonaive patients with unresectable localised or metastatic NSCLC received i.v. vinorelbine 25 mg/m(2) plus carboplatin (AUC 5) on day 1 and oral vinorelbine 60 mg/m(2) on day 8 (or day 15 if neutrophils <1500/mm(3)) every 3 weeks in an open-label, multicentre phase II study.

RESULTS

A total of 224 cycles were given, with the median number per patient of four (range one to eight). Eight responses out of 52 enrolled patients were documented and validated by an independent panel review, yielding a response rate of 18.2% [95% confidence interval (CI) 6.8-29.6%] in the evaluable population. This response rate was balanced by a high rate of disease control (78.9% in the intention-to treat population and 90.9% in the evaluable population). The median progression-free and median survival were 5.1 months (95% CI 4.3-8.1) and 9.3 months (95% CI 6.8-11.4), respectively. Overall, the safety profile of the combination regimen alternating i.v. and oral vinorelbine appeared similar to that expected for each individual agent. Some lung cancer-specific items (pain, dyspnoea) improved or were stabilised by assessment using the EORTC QLQ-C30 and QLQ-LC13 questionnaires.

CONCLUSIONS

The combination of carboplatin with an alternating regimen of i.v./oral vinorelbine is a well tolerated regimen with a low level of toxicity and a low rate of serious adverse events. A high rate of disease control (partial response + no change) was achieved. Progression-free survival and overall survival fell within the expected range. This regimen is convenient and safe for the treatment of patients with locally advanced or metastatic NSCLC patients.

Pharmacology of anticancer drugs in the elderly population

Modifications to bodily functions and physiology are known to occur with age. These changes can have a considerable impact on the pharmacokinetic processes of absorption, distribution, metabolism and excretion and the pharmacodynamic properties of administered drugs. For many drugs with a high therapeutic index, this will be clinically unimportant, but for anticancer drugs, which usually have a low therapeutic index, these pharmacological changes can lead to dramatic consequences, such as excessive drug concentrations and unacceptable toxicity, or subtherapeutic drug concentrations and ineffective treatment. Despite the increased susceptibility of the elderly to these changes, doses are rarely adapted on the basis of pharmacokinetics and pharmacodynamics, with the exception of changes secondary to altered renal function. Until recently, only a few large prospective randomised trials have provided evidence-based data for dose adaptations in elderly patients. However, with increasing knowledge of the pharmacokinetics of anticancer drugs, advances in the knowledge of pharmacokinetic behaviour with aging, and documented efficacy and toxicity data in the elderly population, it is possible to highlight aspects of prescribing anticancer drugs in the elderly. In general, and for most drugs, age itself is not a contraindication to full-dose chemotherapy. The main limiting factors are comorbidity and poor functional status, which may be present in a significant number of the elderly population. Elderly patients with cancer are part of the daily practice of oncologists, but currently clinicians can often only estimate whether dose modification is advantageous for the elderly. This review attempts to elucidate the factors that can influence the pharmacokinetics of anticancer drugs frequently used in the elderly, and the clinical or biochemical parameters that form the basis for dose adjustments with age.

Non–Small-Cell Lung Cancer in Elderly Patients: Influence of Age on Vinorelbine Oral Pharmacokinetics

The majority of cancer-related deaths are attributed to lung carcinoma. Age increases this incidence, which is also likely associated with physiologic modifications that affect drug pharmacokinetics and metabolism. Therefore, knowledge of pharmacokinetics in elderly patients is one of the major factors in deciding whether or not to reduce the dose to prevent toxicity. This phase II study was aimed at evaluating the influence of age on oral vinorelbine pharmacokinetics in elderly patients with non-small-cell lung cancer (NSCLC). Inclusion criteria were > 70 years of age; histologically or cytologically proven NSCLC; inoperable stage IIIB, IV, or delayed relapse of any stage becoming unresectable; Karnofsky performance status > 80%; and normal hematology and biochemistry. Blood-limited sampling at intervals of 1.5, 3, and 24 hours after dosing was performed during the first administration of oral vinorelbine at 60 mg/m2. Bayesian pharmacokinetic parameters were calculated through previously published nonlinear mixed-effect modeling (NONMEM), and compared with a reference population of 52 patients (age, 56 years 12) selected from vinorelbine pharmacokinetic database. There were 48 patients evaluable for pharmacokinetics out of the 52 elderly patients enrolled (age, 74 years 3). There was no difference between pharmacokinetic parameters, including the bioavailability factor evaluated by NONMEM, even without intravenous administration, and a similar interindividual variability (32%-33%) was observed between the 2 groups. Furthermore, no correlation between age (range, 31-82 years) and oral vinorelbine total clearance was observed in 100 patients pooled together. Therefore, no requirement for oral vinorelbine dose reduction was suggested from a pharmacokinetic standpoint.

Oral vinorelbine in combination with cisplatin: a novel active regimen in advanced non-small-cell lung cancer

BACKGROUND

A phase II trial of alternating i.v. and oral vinorelbine in combination with cisplatin was designed to determine the response rate, safety profile, progression-free survival, overall survival and quality of life (QoL) in advanced non-small-cell lung cancer (NSCLC).

PATIENTS AND METHODS

Fifty-six chemotherapy-naïve patients received cisplatin 100 mg/m(2) and i.v. vinorelbine 25 mg/m(2) on day 1, followed by oral vinorelbine 60 mg/m(2) on days 8, 15 and 22, every 28 days.

RESULTS

After an independent review, the response rate was 33% [95% confidence interval (CI) 20% to 46%]. Median progression-free and overall survival were 5.5 months (95% CI 3.7-6.4) and 8.9 months (95% CI 8.8-11.7), respectively. The most frequent hematological toxicities were neutropenia (grade 3-4 in 73% of patients) and anemia (grade 3-4 in 11% of patients). Grade 3-4 infections and non-hematological toxicities occurred occasionally. QoL for lung cancer related symptoms was stable or improved.

CONCLUSIONS

The efficacy and safety of the alternating vinorelbine schedule (i.v. on day 1, oral on days 8, 15 and 22) in combination with cisplatin in advanced NSCLC are similar to those of the standard regimen using exclusively i.v. vinorelbine, whereas ease of administration and patient comfort may favor the novel approach.