Efficacy and safety of original EGFR-TKI combined with bevacizumab in advanced lung adenocarcinoma patients harboring EGFR-mutation experiencing gradual progression after EGFR-TKI treatment: a single-arm study.

Background: Keeping on original epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) treatment is the standard treatment for gradual progression EGFR-positive metastatic non-small cell lung cancer (NSCLC). Angiogenic pathway can lead to EGFR-TKI resistance, but the effectiveness of combination strategies in this group is still controversial. This study aimed to assess the efficacy and safety of the original EGFR-TKI combined with bevacizumab in advanced and metastatic lung adenocarcinoma patients harboring EGFR-mutation who experience gradual progression in a real-world setting. Methods: From June 2019 to December 2021, a total of 35 metastatic EGFR positive NSCLC patients experienced gradual progression after EGFR-TKI treatments and received original TKI combined with bevacizumab were identified at Chongqing University Cancer Hospital, China. All patients were confirmed EGFR positive by rebiopsy before treatment. Patients were treated with EGFR-TKI and bevacizumab (15 mg/kg Q3W) after gradual progression until rapid progression or intolerable toxicity. The overall survival (OS), progression-free survival 1 (PFS1, period from the beginning of EGFR-TKI treatment to the rapid progression of the disease), PFS2 (period from the beginning of EGFR-TKI combined with bevacizumab treatment to the rapid progression of the disease), disease control rate (DCR), and adverse events of the combined treatment were collected and analyzed. Results: A total of 33 patients could participate the efficacy evaluation. Median PFS1 and PFS2 were 20.5 and 8 months, respectively; DCR was 93.94%; median OS was immature. Multivariate Cox proportional hazards model showed that smoking status [hazard ratio (HR) =3.692, 95% confidence interval (CI): 1.450-9.404, P=0.006], combined EGFR T790M mutation or rare mutation (HR =2.480, 95% CI: 1.073-5.729, P=0.034), and malignant pleural effusion (HR =3.707, 95% CI: 1.460-9.414, P=0.006) were independent risk factors for PFS2. The most common treatment-related adverse events greater than grade 3 included hypertension (23.7%), proteinuria (8.3%), and increased alanine aminotransferase (ALT; 4.1%) and aspartate aminotransferase (AST; 2.9%). Conclusions: Continuous original TKI combined with bevacizumab showed partly favorable efficacy and safety and may represent a therapeutic option for metastatic EGFR-mutation NSCLC patients experiencing gradual progression after EGFR-TKI treatment.