Phase II study of the combination of S-1 with bevacizumab for patients with previously treated advanced non-squamous non-small-cell lung cancer

Background We assessed the efficacy and safety of bevacizumab and S-1 chemotherapy for patients with previously treated advanced non-squamous non-small-cell lung cancer (NSCLC). Methods This was a prospective single-arm study, including patients with non-squamous NSCLC who had received at least one chemotherapy regimen along with a platinum-based regimen. Bevacizumab 15 mg/kg was intravenously administered every 3 weeks, and S-1 40 mg/m(2) was orally administered twice daily from day 1 (evening) through day 15 (morning). The treatment continued for 3 weeks/cycle until disease progression or until unacceptable toxicities occurred. During the lead-in part, six patients were evaluated for dose-limiting toxicity (DLT) rate. In phase II, the primary endpoint was objective response rate (ORR). Secondary endpoints were progression-free survival (PFS), overall survival (OS), and safety. Results In the lead-in part, we evaluated the safety in the first six patients and observed no DLT. In phase II, a total of 46 patients were enrolled from September 2012 to December 2018. The median follow-up duration was 13.7 months [95% confidence interval (CI) 1.4-72.0]. The ORR was 28.3%. The median PFS and OS were 4.3 (95% CI 2.9-5.9) and 15.0 months (95% CI 9.8-30.3), respectively. The most common adverse events were hypertension (65.2%), diarrhea (47.8%), mucositis oral (45.7%), and proteinuria (43.5%), and the most common grade 3 adverse events were hypertension (23.9%) and proteinuria (6.5%). Grade 4/5 adverse events were not observed. Conclusion Bevacizumab and S-1 combination chemotherapy showed high activity and were well tolerated in patients with previously treated advanced non-squamous NSCLC.