Metronomic vinorelbine (oral) in combination with sorafenib in advanced non-small cell lung cancer

To date, biomarkers to predict benefit from anti-angiogenic therapy are still lacking. Sorafenib and metronomic oral vinorelbine combination was studied and changes in blood and DCE-MRI parameters were investigated as biomarkers for benefit.

Patients with advanced NSCLC were recruited to 3 successive cohorts. Each cohort was given a fixed metronomic (3 times a week) dose of oral vinorelbine at 60 mg/week, 90 mg/week, or 120 mg/week respectively. Within each cohort, patients received a starting dose of sorafenib at 200mg bid for 4 weeks. In the absence of dose-limiting toxicities, each patient's dose of sorafenib was escalated to 400mg bid for 4 weeks, 600 mg bid for 4 weeks and finally 800 mg bid. Biomarkers measured include DCE-MRI parameters, circulating endothelial cells (CECs), circulating endothelial progenitor cells (CEPs), and plasma thrombospondin (TSP-1).

48 evaluable patients were analyzed. There were 4 (8.9%) patients with partial response (PR) and 7 (15.2%) with cavitary response (CaR). Two subpopulations of CECs (CEC(hi), CEC(lo)) were identified that trended in opposite directions during treatment, with CEC(hi) demonstrating an upward trend in contrast to CEC(lo). Higher baseline CEC(hi) and lower baseline blood flow (F) and fractional intravascular blood volume (V1) predicted for response. Multivariate analysis revealed a lower baseline V1, and dynamic changes of CEC during treatment (CEC increase, sum of CEC(hi) and CEC(lo)) predicted for improved survival.

Sorafenib and metronomic oral vinorelbine is active in advanced NSCLC. Baseline levels and changes in DCE parameters and CEC may be useful predictive biomarkers.