Osimertinib With or Without Bevacizumab in Treating Patients With EGFR Positive Non-small Cell Lung Cancer and Brain Metastases

PRIMARY OBJECTIVE: I. To determine the progression-free survival with osimertinib (AZD9291) plus bevacizumab compared to osimertinib (AZD9291) alone. SECONDARY OBJECTIVES: I. To assess the safety and tolerability of the combination of osimertinib (AZD9291) and bevacizumab. II. To evaluate the time to progression in the central nervous system (CNS) with osimertinib (AZD9291) plus bevacizumab versus single-agent osimertinib (AZD9291). III. To determine the overall response rate and the intracranial response rate to the combination versus single agent. IV. To assess the overall survival in patients receiving osimertinib (AZD9291) plus bevacizumab compared to osimertinib (AZD9291) alone. TRANSLATIONAL OBJECTIVES: I. To investigate mechanisms of sensitivity and resistance to combination osimertinib (AZD9291) plus bevacizumab versus osimertinib (AZD9291) by molecularly characterizing tumor samples including T790M status. II. To assess whether circulating tumor deoxyribonucleic acid (DNA) in plasma can be used as an indicator of sensitivity and resistance to treatment. III. To determine whether an angiogenic signature using a multiplex panel array is associated with benefit from the combination of osimertinib (AZD9291) plus bevacizumab. IV. To investigate angiogenesis, immune and signaling pathway markers in tumor samples to determine biomarkers predictive of benefit from combination therapy. OUTLINE: Patients are randomized to 1 of 2 arms. ARM I: Patients receive osimertinib orally (PO) once daily (QD) on days 1-21 and bevacizumab intravenously (IV) over 30-90 minutes on day 1. Cycles repeat every 21 days in the absence of disease progression or unacceptable toxicity. ARM II: Patients receive osimertinib PO QD on days 1-21. Cycles repeat every 21 days in the absence of disease progression or unacceptable toxicity. Patients undergo computed tomography (CT) scan, magnetic resonance imaging (MRI), tumor biopsy and blood sample collection throughout the study. After completion of study treatment, patients are followed up for a minimum of 4 weeks.