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.