Switch maintenance chemotherapy using S-1 with or without bevacizumab in patients with advanced non-small cell lung cancer: a phase II study

- This is the first prospective clinical study to evaluate switch maintenance therapy with S-1.
- Switch maintenance chemotherapy with S-1 in combination with bevacizumab yielded modest efficacy.
- Toxicities were mild and acceptable.

ObjectivesWe conducted this single-institute; prospective, non-randomized parallel two-arm phase II study to evaluate the efficacy and safety of switch maintenance chemotherapy with S-1 after induction therapy with a platinum-based regimen in patients with advanced non-small cell lung cancer (NSCLC).Patients and methodsPatients not showing disease progression after induction platinum-based chemotherapy received S-1 at the dose of 40 mg/m2 twice daily for 14 consecutive days, every three weeks, with or without bevacizumab (Bev) at the dose of 15 mg/kg. In cases where the induction chemotherapy regimen contained Bev, Bev was used as continuation maintenance chemotherapy where appropriate. The efficacy/toxicity of switch maintenance chemotherapy with S-1 and S-1 + Bev was evaluated separately. The primary end point of this study was the treatment success rate at three months after the start of S-1 treatment.ResultsBetween July 2010 and January 2014, 79 patients were enrolled, of which 78 were found to be eligible for inclusion in this study. The treatment success rate at three months was 28.2% (90% confidence interval (CI), 7.1-17.1%) in the S-1 group and 64.1% (90% CI, 50.0-76.8%) in the S-1 + Bev group. The primary endpoint was met in the S-1 + Bev group. The median PFS and OS were 2.6 months and 11.0 months in the S-1 group, and 4.6 months and 19.9 months in the S-1 + Bev group, respectively. The most common grade three toxicity was neutropenia (10% incidence in the S-1 + Bev group). There were no cases of febrile neutropenia.ConclusionsSwitch maintenance chemotherapy with S-1 in combination with continuation maintenance chemotherapy with bevacizumab yielded modest efficacy with mild and acceptable toxicities.