BAY 43-9006 (Sorafenib) to Treat Relapsed Non-Small Cell Lung Cancer

Despite advances in systemic chemotherapy, patients with stage IV NSCLC will die from their disease. The median survival of all patients is 8-16 months, with a one year-survival rate of 33%. Chemotherapy is the mainstay of treatment of advanced disease. Based on available data from randomized trials, current treatment recommendations are to treat with one of several effective cisplatin-doublets which have resulted in median survival of 16 to 18 months. Second line chemotherapy is able to improve outcome in patients who have had prior cisplatin therapy. Although these important milestones represent improvements in the care of patients with metastatic NSCLC, outcome has not been able to be further improved by substituting one active drug for another in a platinum-based doublet, treating patients with more than four cycles of chemotherapy or by using cisplatin-based triplets. It is clear that if we are to improve outcome of NSCLC patients, we will need to develop drugs with novel mechanisms of action that perhaps will inhibit major cellular signaling pathways affecting survival, proliferation and angiogenesis. One new compound, BAY 43-9006, was designed to inhibit Raf and is also known to inhibit other kinases including VEGFR2, VEGFR3, PDGFR-beta, Flt3, c-KIT, and p38(1). BAY 43-9006 has shown in vitro activity against NSCLC cell lines NCI-H460 and A549 with tumor growth inhibition of 27% to 68%. In addition, BAY 43-9006 has shown activity in the H460 NSCLC xenograft model. In NSCLC, the proliferation signaling of the Ras/Raf/MEK/ERK pathway is increased due to the frequent (30%) presence of K-ras mutations in the tumor. Mutations in K-ras have been associated with malignant transformation of normal epithelium and constitutive activation of p21 and its downstream effects on cellular proliferation and inhibition of apoptosis. Clinical observations have shown that tumors with K-ras mutations tended to be smaller but more poorly differentiated, and associated with a significantly worse three-year mortality rate. As mentioned above, other pathways significant to the malignant potential of NSCLC, particularly those involved in angiogenesis, may also be affected by BAY 43-9006. The in vitro and in vivo data support the clinical investigation of BAY 43-9006 as an inhibitor of the Ras/Raf/MEK/ERK downstream proliferation effects. The goal of this phase II trial is to determinate if BAY 43-9006 is active in NSCLC, and to measure the BAY 43-9006 biological effects on the Ras/Raf/MEK/ERK pathway. To achieve these goals, patients with relapsed or recurrent NSCLC will be given BAY 43-9006 (four weeks cycle of 400mg PO BID). A series of correlative studies will be done during treatment to measure biological and clinical effects of BAY 43-9006. These studies will include analyses of tissue and blood samples as well as correlative imaging studies.