Safety and efficacy of second-line metronomic oral vinorelbine-atezolizumab combination in stage IV non-small-cell lung cancer: An open-label phase II trial (VinMetAtezo)

Objective To evaluate the safety and efficacy of second-line metronomic oral vinorelbine–atezolizumab combination for stage IV non-small-cell lung cancer. Methods This was a multicenter, open-label, single-arm Phase II study performed in patients with advanced NSCLC without activating EGFR mutation or ALK rearrangement who progressed after first-line platinum-doublet chemotherapy. Combination treatment was atezolizumab (1200 mg IV day 1, every 3 weeks) and oral vinorelbine (40 mg, 3 times by week). The primary outcome was progression-free survival (PFS) during the 4-month follow-up from the first dose of treatment. Statistical analysis was based on the exact single-stage Phase II design defined by A'Hern. Based on literature data, the Phase III trial threshold was set at 36 successes in 71 patients. Results 71 patients were analyzed (median age, 64 years; male, 66.2%; ex-smokers/active smokers, 85.9%; ECOG performance status 0–1, 90.2%; non-squamous NSCLC, 83.1%; PD-L1 ≥ 50%, 4.4%). After a median follow-up of 8.1 months from treatment initiation, 4-month PFS rate was 32% (95% CI, 22–44), i.e. 23 successes out 71 patients. OS rate was 73.2% at 4 months and 24.3% at 24 months. Median PFS and OS were 2.2 (95% CI, 1.5–3.0) months and 7.9 (95% CI, 4.8–11.4) months, respectively. Overall response rate and disease control rate at 4 months were 11% (95% CI, 5–21) and 32% (95% CI, 22–44), respectively. No safety signal was evidenced. Conclusion Metronomic oral vinorelbine-atezolizumab in the second-line setting did not achieve the predefined PFS threshold. No new safety signal was reported for vinorelbine-atezolizumab combination.