The purpose of this study is to determine the efficacy of pembrolizumab given in combination with either ipilimumab or placebo as first-line treatment in participants with metastatic non-small cell lung cancer (NSCLC). The primary hypothesis of this study is that overall survival (OS) and/or progression-free survival (PFS) is prolonged in participants who receive pembrolizumab and ipilimumab compared to those who receive pembrolizumab and placebo.
With Amendment 6 (effective date: 11-Dec-2020), active participants, investigator, and sponsor personnel or delegate(s) involved in the treatment administration or clinical evaluation of the participants will be unblinded. Participants will discontinue ipilimumab and placebo and participants who remain on treatment will receive open-label pembrolizumab only.
