Study of Oral Vinorelbine and Erlotinib in Non-Small Cell Lung Cancer

Additive or supraadditive activity of an EGFR TK-I with vinorelbine has been demonstrated in-vitro. Clinical synergism has also been described between gefitinib and vinorelbine in NSCLC. The use of cytotoxics in a metronomic schedule has not been well investigated in the clinical setting despite emerging pre-clinical data. Using an established oral cytotoxic such as oral vinorelbine in a metronomic dose-schedule is attractive due to the oral route of administration. Preclinical studies have shown that by using cytotoxics in a low-dose protracted manner, endothelial cells are preferentially affected via inhibition of proliferation and induction of apoptosis. In addition to this anti-angiogenic mechanism, an anti-vasculogenic process may also be involved that acts by reducing circulating endothelial progenitor mobilization and viability. Moreover, it has also been shown that tumours that were selected for high levels of acquired resistance to cytotoxics can be induced to respond by using metronomic doses of chemotherapy. Continuous administration of metronomic oral vinorelbine, given three times a week, has been reported as feasible and well tolerated at doses up to 180 mg total dose per week. Early results showed activity against refractory solid tumors such as renal cancer, NSCLC, ovarian cancer, prostate cancer, unknown primary and Kaposi sarcoma. This phase I study combines erlotinib and oral vinorelbine on two different schedules. The conventional schedule vinorelbine (CSV) aims to determine the MTD of conventional schedule of oral vinorelbine given on days 1 and 8 every 21 days plus daily erlotinib and the metronomic schedule vinorelbine (MSV) aims to determine the optimal metronomic dose of vinorelbine given 3 times a week plus daily erlotinib.