A phase I study of vinflunine in combination with capecitabine in patients with metastatic breast cancer previously treated with anthracyclines and taxanes

Randomised phase III trial of vinflunine plus capecitabine versus capecitabine alone in patients with advanced breast cancer previously treated with an anthracycline and resistant to taxane

Background

Capecitabine is an approved standard therapy for anthracycline- and taxane-pretreated locally advanced or metastatic breast cancer (BC). Vinflunine has demonstrated single-agent activity in phase II studies in this setting and activity and tolerability when combined with capecitabine. We compared the combination of vinflunine plus capecitabine (VC) with single-agent capecitabine.

Patients and methods

Patients with locally recurrent/metastatic BC previously treated or resistant to an anthracycline and resistant to taxane therapy were randomly assigned to either vinflunine (280 mg/m2, day 1) plus oral capecitabine [825 mg/m2 twice daily (b.i.d.), days 1-14] every 3 weeks (q3w) or single-agent oral capecitabine (1250 mg/m2 b.i.d., days 1-14) q3w. The primary end point was progression-free survival (PFS) assessed by an independent review committee. The study had 90% power to detect a 30% improvement in PFS.

Results

Overall, 770 patients were randomised. PFS was significantly longer with VC than with capecitabine alone [hazard ratio, 0.84, 95% confidence interval (CI), 0.71-0.99; log-rank P = 0.043; median 5.6 versus 4.3 months, respectively]. Median overall survival was 13.9 versus 11.7 months with VC versus capecitabine alone, respectively (hazard ratio, 0.98; 95% CI, 0.83-1.15; log-rank P = 0.77). No difference in quality of life was observed between the two treatment arms. The most common adverse events (NCI CTCAE version 3.0) in the combination arm were haematological and gastrointestinal. Grade 4 neutropenia was more frequent with VC (12% versus 1% with capecitabine alone); febrile neutropenia occurred in 2% versus 0.5%, respectively. Hand-foot syndrome was less frequent with VC (grade 3: 4% versus 19% for capecitabine alone). Peripheral neuropathy was uncommon in both arms (grade 3: 1% versus 0.3%).

Conclusions

Vinflunine combined with capecitabine demonstrated a modest improvement in PFS and an acceptable safety profile compared with capecitabine alone in patients with anthracycline- and taxane-pretreated locally recurrent/metastatic BC.

ClinicalTrials.gov

NCT01095003.

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.

Anti-mitotic agents: Are they emerging molecules for cancer treatment?

Mutations in cancer cells frequently result in cell cycle alterations that lead to unrestricted growth compared to normal cells. Considering this phenomenon, many drugs have been developed to inhibit different cell-cycle phases. Mitotic phase targeting disturbs mitosis in tumor cells, triggers the spindle assembly checkpoint and frequently results in cell death. The first anti-mitotics to enter clinical trials aimed to target tubulin. Although these drugs improved the treatment of certain cancers, and many anti-microtubule compounds are already approved for clinical use, severe adverse events such as neuropathies were observed. Since then, efforts have been focused on the development of drugs that also target kinases, motor proteins and multi-protein complexes involved in mitosis. In this review, we summarize the major proteins involved in the mitotic phase that can also be targeted for cancer treatment. Finally, we address the activity of anti-mitotic drugs tested in clinical trials in recent years.

Vinflunine for the treatment of breast cancer

INTRODUCTION

Breast cancer is the most frequently diagnosed cancer and the highest cause of cancer mortality in females worldwide. The development of drugs improving overall survival in late-stage metastatic breast cancer remains a challenge. Vinflunine is the most recently developed drug in the vinca alkaloid class. Its arrival has been eagerly awaited for treatment of solid tumors, and in particular, for metastatic breast cancer.

AREAS COVERED

The pharmacological features of vinflunine are described. Its clinical development as monotherapy or in combination in metastatic breast cancer is detailed. A literature search on the topic was conducted through PubMed, clinical trials and the proceedings of the main cancer congresses.

EXPERT OPINION

The overall results from phase III studies, and in particular those that combined vinflunine with capecitabine, have been less favorable. The combination's effectiveness was at best moderate compared with other drugs which also target metastatic breast cancer, and complicated by significant hematological and gastrointestinal adverse effects. Its use in advanced metastatic breast cancer cannot currently be recommended.