[Efficacy of Osimertinib Combined with Bevacizumab in Advanced Non-small Cell 
Lung Cancer Patients with Acquired EGFR T790M Mutation].

Background: Osimertinib is a third-generation epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) capable of overcoming non-small cell lung cancer (NSCLC) with EGFR T790M mutation. Although the addition of bevacizumab to 1st generation EGFR-TKIs confers a significant improvement in progression-free survival (PFS) in treatment-naive EGFR mutant NSCLC patients, osimertinib plus bevacizumab combination failed to show prolongation in the phase 2 study WJOG8715L. Data of such combination in Chinese patients are still lacking. This study aimed to explore the efficacy of the addition of bevacizumab to osimertinib as second-line therapy in real-world data, and to evaluate the role of anti-angiogenesis plus osimertinib combination therapeutic strategies in pretreated Chinese NSCLC patients with acquired EGFR T790M mutation.
Methods: A total of 42 advanced NSCLC patients with acquired EGFR T790M mutation after prior EGFR-TKIs treatment were collected between January 2020 to August 2021, with 16 cases treated with osimertinib plus bevacizumab and 26 cases treated with osimertinib. The treatment effect of patients were analyzed.
Results: The objective response rate (ORR) in combination group and osimertinib group were 43.8% and 50.0% respectively (P=0.694). No statistically significant difference in median PFS (14.0 mon vs 13.0 mon, P=0.797) and overall survival (OS) (29.0 mon vs 26.0 mon, P=0.544) between the combination group and osimertinib group were observed. Prior history of bevacizumab was identified as an independent predictor of PFS (P=0.045) and OS (P=0.023).
Conclusions: Our study demonstrated that adding bevacizumab to osimertinib could not show advantages in PFS and OS in pretreated NSCLC patients harboring EGFR T790M-mutation.