Bevacizumab in the Treatment of Malignant Pleural Effusions of Non-squamous Non-small Cell Lung Cancer

This study is a prospective, multicenter, randomized, phase II clinical study. 87 patients will be recruited. Group A (low dose group) Intrapleural injection of bevacizumab 2.5mg/kg/times, d1, d8; 21 days for a course of treatment. Subjects will received two courses of treatment if there is no termination of treatment listed in the standard. Group B (medium dose group) Intrapleural injection of bevacizumab 5mg/kg/times, d1, d8; 21 days for a course of treatment. Subjects will received two courses of treatment if there is no termination of treatment listed in the standard. Group C (high dose group) Intrapleural injection of bevacizumab 7.5mg/kg/times, d1, d8; 21 days for a course of treatment. Subjects will received two courses of treatment if there is no termination of treatment listed in the standard. Main evaluation criteria: pleural effusion objective response rate(ORR) (WHO standard) Secondary evaluation criteria: pleural fluid time to progression (TTP), overall survival (OS), ORR, QOL scores (Quality of Life Questionnaire-lung cancer) and KPS, and safety (NCI CTCAE V4.03)