Intra-patient Dose Escalation Study of Sorafenib in Advanced Non-small Cell Lung Cancer

Inclusion Criteria: * Histologically or cytologically confirmed, advanced (stage IIIB with pleural effusion, stage IV, or recurrent), kras mutation positive, non-small cell lung cancer (NSCLC) * Measurable disease per RECIST criteria * Patients must have received one + prior chemotherapy regimens for NSCLC * Patients may have treated and clinically stable brain metastases * Adequate bone marrow, liver and renal function * Women of childbearing potential must have a negative serum pregnancy test within 7 days prior to the start of treatment * Women of childbearing potential and men must agree to use adequate contraception (barrier method of birth control) prior to study entry and for the duration of study participation, and for 3 months after last administration of sorafenib * Patients must have the ability to understand and willingness to sign a written informed consent * International normalized ratio(INR) \< 1.5 or prothrombin time/ partial thromboplastin time (PT/PTT) within normal limits Exclusion Criteria: * Prior exposure to a Ras pathway inhibitor * Any other anti-tumor therapy within 3 weeks of enrollment * Prior bevacizumab within the past 6 weeks * An active secondary malignancy except non-melanoma skin cancer * Cardiac disease: Congestive heart failure \> class II NYHA. Patients must not have unstable angina or new onset angina or myocardial infarction within the past 6 months * Cardiac ventricular arrhythmias requiring anti-arrhythmic therapy * Uncontrolled hypertension, defined as systolic blood pressure \> 150mm Hg or diastolic pressure \> 90mm Hg, despite optical medical management * Known human immunodeficiency virus (HIV) infection or chronic Hepatitis B or C * Active clinically serious infection \> Common Terminology Criteria for Adverse Events (CTCAE) Grade 2 * Thrombolic or embolic events such as cerebrovascular accident including transient ischemic attack within the past 6 months * Pulmonary hemorrhage/bleeding event \>/= CTCAE Grade 2 within 4 weeks of first dose of study drug * Any other hemorrhage/bleeding event \>/= CTCAE Grade 3 within 4 weeks of first dose of study drug * Serious non-healing wound, ulcer, or bone fracture * Evidence or history of bleeding diathesis or coagulopathy * Major surgery, open biopsy or significant traumatic injury within 4 weeks of first study drug * Use of St. John's Wort or rifampin * Known or suspected allergy to sorafenib or any agent given in the course of the trial * Any condition that impairs patient's ability to swallow whole pills * Any malabsorption problem