Metronomic treatment of advanced non-small-cell lung cancer with daily oral vinorelbine - a Phase I trial

Micro-abstract: In a Phase I dose-finding study of metronomic daily oral vinorelbine in advanced non-small-cell lung cancer, a recommended dose was established for this therapeutic approach. In addition, this trial revealed promising efficacy data and an acceptable tolerability profile. The observed vinorelbine blood concentrations suggest continuous anti-angiogenic coverage. Introduction: We present a Phase I dose-finding study investigating metronomic daily oral vinorelbine (Navelbine (R) Oral, NVBo) in advanced non-small-cell lung cancer (NSCLC). Patients and methods: Patients with stage III/IV NSCLC received daily NVBo at fixed dose levels of 20-50 mg/d for 21 days of each 4-week cycle. Primary end point was the maximum tolerated dose. Secondary end points included tumor response, time to progression (TTP), overall survival (OS) and tolerability. Results: Twenty-seven patients with advanced NSCLC were enrolled. Most of them were extensively pretreated. Daily NVBo was well tolerated up to 30 mg/d. At 40 mg/d, two of five patients experienced dose-limiting toxicities (DLTs). Three of six patients had DLTs at the 50 mg/d level. The recommended dose was established at 30 mg/d in cycle 1, with escalation to 40 mg/d in cycle 2, if tolerated. Pharmacokinetic analyses showed continuous blood exposure over 21 days and only marginal accumulation. The tolerability profile was acceptable (all dose levels - all grades: decreased appetite 33%, diarrhea 33%, leukopenia 33%, nausea 30%, vomiting 26%; >= grade 3: leukopenia 30%, lymphopenia 19%, neutropenia 19%, febrile neutropenia 15%). Disease control rate, OS and TTP signaled a treatment effect. Conclusion: Daily metronomic NVBo therapy in extensively pretreated patients with advanced NSCLC is feasible and safe at the recommended dose of 30 mg/d. Escalation to 40 mg/d in the second cycle is possible. The blood concentrations of vinorelbine after daily metronomic dosing reached lower peaks than intravenous or oral conventional dosing. Blood concentrations were consistent with anti-angiogenic or immune modulating pharmacologic properties of vinorelbine. Further studies are warranted to evaluate the safety and efficacy of this novel approach in specific patient populations.