A randomized phase II study of afatinib alone or combined with bevacizumab for treating chemo-naïve patients with non-small cell lung cancer harboring EGFR mutations

Adding bevacizumab to first-generation epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors (TKIs) prolonged the progression-free survival (PFS), but limited data are available for second-generation EGFR-TKIs. AfaBev-CS is a randomized, phase II trial comparing afatinib plus bevacizumab and afatinib alone as first-line treatment.Untreated patients with non-squamous non-small cell lung cancer (NSCLC) harboring EGFR mutations (Del19 or L858R) were enrolled and randomly assigned to receive either afatinib (30 mg) plus bevacizumab (AfaBev group) or afatinib (40 mg) monotherapy (Afa group). The primary endpoint was PFS. The power was >50% under the assumptions of a median PFS of 12 months for the Afa group and hazard ratio (HR) of 0.6 for the AfaBev group.Between August 2017 and September 2019, 100 patients were enrolled. There was no significant difference in PFS between the groups. The median PFS was 16.3 and 16.1 months for the AfaBev and Afa groups, respectively, with an HR of 0.865 (95% confidence interval [CI], 0.539 to 1.388; p = 0.55). In terms of overall survival, there was no significant difference between the groups (HR, 0.84; 95% CI, 0.39 to 1.83; p = 0.67). The overall response rate was 82.6% and 76.6% in the AfaBev and Afa groups, respectively (p = 0.61). Grade ≥ 3 diarrhea, hypertension, acneiform rash, paronychia, and stomatitis were frequently observed in the AfaBev group.This study failed to show efficacy of AfaBev over Afa for improving PFS in untreated patients with EGFR-mutated NSCLC.