An Investigational Immuno-therapy Study of Nivolumab, or Nivolumab in Combination With Ipilimumab, or Placebo in Patients With Extensive-Stage Disease Small Cell Lung Cancer (ED-SCLC) After Completion of Platinum-based Chemotherapy

In this study, all patients must have already completed first-line chemotherapy to treat extensive-stage disease small cell lung cancer. The purpose of this study is to show that nivolumab, or nivolumab plus ipilimumab followed by nivolumab by itself, will prolong overall survival when administered as consolidation treatment in patients that are stable or responding after chemotherapy. Patients receiving treatment will be compared with patients taking placebo.